[PATCH v6 00/39] KVM: arm64: Introduce vGIC-v5 with PPI support

[PATCH v6 00/39] KVM: arm64: Introduce vGIC-v5 with PPI support

[Sascha Bischoff]

This is v6 of the patch series to add the virtual GICv5 [1] device
(vgic_v5). Only PPIs are supported by this initial series, and the
vgic_v5 implementation is restricted to the CPU interface,
only. Further patch series are to follow in due course, and will add
support for SPIs, LPIs, the GICv5 IRS, and the GICv5 ITS.

v1, v2, v3, v4, and v5 of this series can be found at [2], [3], [4],
[5], [6], respectively.

Headline changes since v5:

* Reworked all of the PPI state manipulation (with the exception of
  PPI priorities) to use bitmaps rather than u64 arrays which were
  mapped onto registers. This allows us to manipulate the state much
  more elegantly. PPI priority state was not included in this as we
  have 8-bits per PPI, so using a bitmap is not helpful here.

* Reduced the number of supported PPIs in KVM from 128 to 64, meaning
  that we only support the architected set and not the impdef
  set. Given that we only expose the SW_PPI, PMUIRQ, and the timer
  PPIs to a guest we were handling a lot of state that never got
  used. If the impdef set of PPIs are required in the future, it is
  just a case of bumping the number of PPIs back up to 128 - the code
  is parameterised based on the value now that we use bitmaps.

* Updated the core vgic code to use switch statements rather than
  if-else constructs, where appropriate. This is more readable, and
  maintainable, if more verbose. vgic_restore_state() and
  vgic_save_state() are the exception as the logic becomes rather
  convoluted quickly, and comments have been included to explain
  why. In short, the __vgic_v3_*_state() functions need to be called
  in many different situations, resulting in a complex mess of nested
  switch and if-else statements.

* Introduced some vgic_v5_* helpers to manipulate IntIDs to either
  extract the ID and type, or to build a GICv5-style IntID. These have
  been worked into the appropriate places.

* Moved the vgic_is_v3() from vgic.h helper to live in arm_vgic.h,
  alongside the vgic_is_v5() one. Both are now implemented as macros,
  whereas previously one was a macro and the other was a static inline
  function.

* Separated mapping/unmapping of irqs from setting/clearing the
  irq_ops. We rely on some functions being overridden via irq_ops for
  GICv5, and previously the act of unmapping an irq was
  indiscriminately clearing them. While this is not an issue for
  non-nested operation as irqs are not dynamically unmapped, this
  would have gone very, very wrong with nested virt for GICv5. Now
  mapping/unmapping ONLY handles what the name suggests, and the
  setting/clearing of irq_ops is explicitly handled via
  kvm_vgic_set_irq_ops() and kvm_vgic_clear_irq_ops(). This results in
  some extra code, but avoids conflating the two mechanisms.

* Introduced a set_direct_injection() irq_op, and reimplemented the
  GICv5 PPI DVI mechanism to use this. This keeps the core vgic
  mapping/unmapping code free of special case handling for GICv5. As
  part of this, also dropped the directly_injected flag from struct
  vgic_irq as it was no longer used or useful.

* Dropped the hypercall for __vgic_v5_save_ppi_state() and
  __vgic_v5_restore_ppi_state() as these functions are only ever
  called directly by the relevant VHE/NVHE code, meaning that the
  hypercall itself was never used.

* General clean-up some some of the commit messages to more accurately
  document the commits.

These changes are based on v7.0-rc4. I have pushed these changes to a
branch that can be found at [7].

Thanks all for the feedback! As always, it is greatly appreciated.

Sascha

[1] https://developer.arm.com/documentation/aes0070/latest
[2] https://lore.kernel.org/all/20251212152215.675767-1-sascha.bischoff@arm.com/
[3] https://lore.kernel.org/all/20251219155222.1383109-1-sascha.bischoff@arm.com/
[4] https://lore.kernel.org/all/20260109170400.1585048-1-sascha.bischoff@arm.com/
[5] https://lore.kernel.org/all/20260128175919.3828384-1-sascha.bischoff@arm.com/
[6] https://lore.kernel.org/all/20260226155515.1164292-1-sascha.bischoff@arm.com/
[7] https://gitlab.arm.com/linux-arm/linux-sb/-/tree/gicv5_ppi_support_v6

Sascha Bischoff (39):
  KVM: arm64: vgic-v3: Drop userspace write sanitization for
    ID_AA64PFR0.GIC on GICv5
  KVM: arm64: vgic: Rework vgic_is_v3() and add vgic_host_has_gicvX()
  KVM: arm64: Return early from kvm_finalize_sys_regs() if guest has run
  KVM: arm64: vgic: Split out mapping IRQs and setting irq_ops
  arm64/sysreg: Add remaining GICv5 ICC_ & ICH_ sysregs for KVM support
  arm64/sysreg: Add GICR CDNMIA encoding
  KVM: arm64: gic-v5: Add ARM_VGIC_V5 device to KVM headers
  KVM: arm64: gic: Introduce interrupt type helpers
  KVM: arm64: gic-v5: Add Arm copyright header
  KVM: arm64: gic-v5: Detect implemented PPIs on boot
  KVM: arm64: gic-v5: Sanitize ID_AA64PFR2_EL1.GCIE
  KVM: arm64: gic-v5: Support GICv5 FGTs & FGUs
  KVM: arm64: gic-v5: Add emulation for ICC_IAFFIDR_EL1 accesses
  KVM: arm64: gic-v5: Trap and emulate ICC_IDR0_EL1 accesses
  KVM: arm64: gic-v5: Add vgic-v5 save/restore hyp interface
  KVM: arm64: gic-v5: Implement GICv5 load/put and save/restore
  KVM: arm64: gic-v5: Finalize GICv5 PPIs and generate mask
  KVM: arm64: gic: Introduce queue_irq_unlock to irq_ops
  KVM: arm64: gic-v5: Implement PPI interrupt injection
  KVM: arm64: gic-v5: Init Private IRQs (PPIs) for GICv5
  KVM: arm64: gic-v5: Clear TWI if single task running
  KVM: arm64: gic-v5: Check for pending PPIs
  KVM: arm64: gic-v5: Trap and mask guest ICC_PPI_ENABLERx_EL1 writes
  KVM: arm64: Introduce set_direct_injection irq_op
  KVM: arm64: gic-v5: Implement direct injection of PPIs
  KVM: arm64: gic-v5: Support GICv5 interrupts with KVM_IRQ_LINE
  KVM: arm64: gic-v5: Create and initialise vgic_v5
  KVM: arm64: gic-v5: Initialise ID and priority bits when resetting
    vcpu
  KVM: arm64: gic-v5: Enlighten arch timer for GICv5
  KVM: arm64: gic-v5: Mandate architected PPI for PMU emulation on GICv5
  KVM: arm64: gic: Hide GICv5 for protected guests
  KVM: arm64: gic-v5: Hide FEAT_GCIE from NV GICv5 guests
  KVM: arm64: gic-v5: Introduce kvm_arm_vgic_v5_ops and register them
  KVM: arm64: gic-v5: Set ICH_VCTLR_EL2.En on boot
  KVM: arm64: gic-v5: Probe for GICv5 device
  Documentation: KVM: Introduce documentation for VGICv5
  KVM: arm64: gic-v5: Communicate userspace-driveable PPIs via a UAPI
  KVM: arm64: selftests: Introduce a minimal GICv5 PPI selftest
  KVM: arm64: selftests: Add no-vgic-v5 selftest

 Documentation/virt/kvm/api.rst                |   6 +-
 .../virt/kvm/devices/arm-vgic-v5.rst          |  50 ++
 Documentation/virt/kvm/devices/index.rst      |   1 +
 Documentation/virt/kvm/devices/vcpu.rst       |   5 +-
 arch/arm64/include/asm/el2_setup.h            |   2 +
 arch/arm64/include/asm/kvm_asm.h              |   2 +
 arch/arm64/include/asm/kvm_host.h             |  34 ++
 arch/arm64/include/asm/kvm_hyp.h              |  10 +
 arch/arm64/include/asm/sysreg.h               |   7 +
 arch/arm64/include/asm/vncr_mapping.h         |   3 +
 arch/arm64/include/uapi/asm/kvm.h             |   1 +
 arch/arm64/kvm/arch_timer.c                   | 132 ++++-
 arch/arm64/kvm/arm.c                          |  44 +-
 arch/arm64/kvm/config.c                       | 123 ++++-
 arch/arm64/kvm/emulate-nested.c               |  68 +++
 arch/arm64/kvm/hyp/include/hyp/switch.h       |  27 +
 arch/arm64/kvm/hyp/nvhe/Makefile              |   2 +-
 arch/arm64/kvm/hyp/nvhe/hyp-main.c            |  16 +
 arch/arm64/kvm/hyp/nvhe/switch.c              |  15 +
 arch/arm64/kvm/hyp/nvhe/sys_regs.c            |   8 +
 arch/arm64/kvm/hyp/vgic-v5-sr.c               | 166 ++++++
 arch/arm64/kvm/hyp/vhe/Makefile               |   2 +-
 arch/arm64/kvm/nested.c                       |   5 +
 arch/arm64/kvm/pmu-emul.c                     |  20 +-
 arch/arm64/kvm/sys_regs.c                     | 176 ++++++-
 arch/arm64/kvm/vgic/vgic-init.c               | 213 +++++---
 arch/arm64/kvm/vgic/vgic-kvm-device.c         | 107 +++-
 arch/arm64/kvm/vgic/vgic-mmio.c               |  40 +-
 arch/arm64/kvm/vgic/vgic-v3.c                 |   2 +-
 arch/arm64/kvm/vgic/vgic-v5.c                 | 492 +++++++++++++++++-
 arch/arm64/kvm/vgic/vgic.c                    | 184 +++++--
 arch/arm64/kvm/vgic/vgic.h                    |  53 +-
 arch/arm64/tools/sysreg                       | 480 +++++++++++++++++
 include/kvm/arm_arch_timer.h                  |  11 +-
 include/kvm/arm_pmu.h                         |   5 +-
 include/kvm/arm_vgic.h                        | 191 ++++++-
 include/linux/irqchip/arm-gic-v5.h            |  27 +
 include/linux/kvm_host.h                      |   1 +
 include/uapi/linux/kvm.h                      |   2 +
 tools/arch/arm64/include/uapi/asm/kvm.h       |   1 +
 tools/include/uapi/linux/kvm.h                |   2 +
 tools/testing/selftests/kvm/Makefile.kvm      |   3 +-
 .../testing/selftests/kvm/arm64/no-vgic-v3.c  | 177 -------
 tools/testing/selftests/kvm/arm64/no-vgic.c   | 297 +++++++++++
 tools/testing/selftests/kvm/arm64/vgic_v5.c   | 228 ++++++++
 .../selftests/kvm/include/arm64/gic_v5.h      | 150 ++++++
 46 files changed, 3209 insertions(+), 382 deletions(-)
 create mode 100644 Documentation/virt/kvm/devices/arm-vgic-v5.rst
 create mode 100644 arch/arm64/kvm/hyp/vgic-v5-sr.c
 delete mode 100644 tools/testing/selftests/kvm/arm64/no-vgic-v3.c
 create mode 100644 tools/testing/selftests/kvm/arm64/no-vgic.c
 create mode 100644 tools/testing/selftests/kvm/arm64/vgic_v5.c
 create mode 100644 tools/testing/selftests/kvm/include/arm64/gic_v5.h

-- 
2.34.1

[PATCH v6 01/39] KVM: arm64: vgic-v3: Drop userspace write sanitization for ID_AA64PFR0.GIC on GICv5

[Sascha Bischoff]

Drop a check that blocked userspace writes to ID_AA64PFR0_EL1 for
writes that set the GIC field to 0 (NI) on GICv5 hosts. There is no
such check for GICv3 native systems, and having inconsistent behaviour
both complicates the logic and risks breaking existing userspace
software that expects to be able to write the register.

This means that userspace is now able to create a GICv3 guest on GICv5
hosts, and disable the guest from seeing that it has a GICv3. This
matches the already existing behaviour for GICv3-native VMs.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
---
 arch/arm64/kvm/sys_regs.c | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 1b4cacb6e918a..4b9f4e5d946b1 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -2177,14 +2177,6 @@ static int set_id_aa64pfr0_el1(struct kvm_vcpu *vcpu,
 	    (vcpu_has_nv(vcpu) && !FIELD_GET(ID_AA64PFR0_EL1_EL2, user_val)))
 		return -EINVAL;
 
-	/*
-	 * If we are running on a GICv5 host and support FEAT_GCIE_LEGACY, then
-	 * we support GICv3. Fail attempts to do anything but set that to IMP.
-	 */
-	if (vgic_is_v3_compat(vcpu->kvm) &&
-	    FIELD_GET(ID_AA64PFR0_EL1_GIC_MASK, user_val) != ID_AA64PFR0_EL1_GIC_IMP)
-		return -EINVAL;
-
 	return set_id_reg(vcpu, rd, user_val);
 }
 
-- 
2.34.1

Re: [PATCH v6 01/39] KVM: arm64: vgic-v3: Drop userspace write sanitization for ID_AA64PFR0.GIC on GICv5

[Jonathan Cameron]

On Tue, 17 Mar 2026 11:40:13 +0000
Sascha Bischoff <Sascha.Bischoff@arm.com> wrote:

> Drop a check that blocked userspace writes to ID_AA64PFR0_EL1 for
> writes that set the GIC field to 0 (NI) on GICv5 hosts. There is no
> such check for GICv3 native systems, and having inconsistent behaviour
> both complicates the logic and risks breaking existing userspace
> software that expects to be able to write the register.
> 
> This means that userspace is now able to create a GICv3 guest on GICv5
> hosts, and disable the guest from seeing that it has a GICv3. This

Just to clarify this is removing a check on a nonsensical setup?
I'm not against it if that simplifies things but I couldn't quite
parse the description.

> matches the already existing behaviour for GICv3-native VMs.
> 
> Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
> ---
>  arch/arm64/kvm/sys_regs.c | 8 --------
>  1 file changed, 8 deletions(-)
> 
> diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
> index 1b4cacb6e918a..4b9f4e5d946b1 100644
> --- a/arch/arm64/kvm/sys_regs.c
> +++ b/arch/arm64/kvm/sys_regs.c
> @@ -2177,14 +2177,6 @@ static int set_id_aa64pfr0_el1(struct kvm_vcpu *vcpu,
>  	    (vcpu_has_nv(vcpu) && !FIELD_GET(ID_AA64PFR0_EL1_EL2, user_val)))
>  		return -EINVAL;
>  
> -	/*
> -	 * If we are running on a GICv5 host and support FEAT_GCIE_LEGACY, then
> -	 * we support GICv3. Fail attempts to do anything but set that to IMP.
> -	 */
> -	if (vgic_is_v3_compat(vcpu->kvm) &&
> -	    FIELD_GET(ID_AA64PFR0_EL1_GIC_MASK, user_val) != ID_AA64PFR0_EL1_GIC_IMP)
> -		return -EINVAL;
> -
>  	return set_id_reg(vcpu, rd, user_val);
>  }
>  

Re: [PATCH v6 01/39] KVM: arm64: vgic-v3: Drop userspace write sanitization for ID_AA64PFR0.GIC on GICv5

[Sascha Bischoff]

On Thu, 2026-03-19 at 10:02 +0000, Jonathan Cameron wrote:
> On Tue, 17 Mar 2026 11:40:13 +0000
> Sascha Bischoff <Sascha.Bischoff@arm.com> wrote:
> 
> > Drop a check that blocked userspace writes to ID_AA64PFR0_EL1 for
> > writes that set the GIC field to 0 (NI) on GICv5 hosts. There is no
> > such check for GICv3 native systems, and having inconsistent
> > behaviour
> > both complicates the logic and risks breaking existing userspace
> > software that expects to be able to write the register.
> > 
> > This means that userspace is now able to create a GICv3 guest on
> > GICv5
> > hosts, and disable the guest from seeing that it has a GICv3. This
> 
> Just to clarify this is removing a check on a nonsensical setup?
> I'm not against it if that simplifies things but I couldn't quite
> parse the description.

Effectively, we were being more strict when running with GICv3 on a
GICv5 host than when running natively on a GICv3 host. This by itself
wasn't too big an issue, but it can cause existing software break if it
relies on being able to hide GICv3 this way (for whatever reason...),
and somewhat breaks the portability story.

Moreover, we test these sorts of things in the selftests. If a virtual
GICv3 is created but then userspace comes along and zeros the feature
bits (so, hides the feature), we expect the FGU infrastructure to take
over to undef registers/instructions related to that feature. So, in
this case, rather than letting userspace hide the virtual GICv3 from
the guest, we instead stopped it from hiding it.

Does that make some sort of sense?

Thanks,
Sascha

> 
> > matches the already existing behaviour for GICv3-native VMs.
> > 
> > Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
> > ---
> >  arch/arm64/kvm/sys_regs.c | 8 --------
> >  1 file changed, 8 deletions(-)
> > 
> > diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
> > index 1b4cacb6e918a..4b9f4e5d946b1 100644
> > --- a/arch/arm64/kvm/sys_regs.c
> > +++ b/arch/arm64/kvm/sys_regs.c
> > @@ -2177,14 +2177,6 @@ static int set_id_aa64pfr0_el1(struct
> > kvm_vcpu *vcpu,
> >  	    (vcpu_has_nv(vcpu) && !FIELD_GET(ID_AA64PFR0_EL1_EL2,
> > user_val)))
> >  		return -EINVAL;
> >  
> > -	/*
> > -	 * If we are running on a GICv5 host and support
> > FEAT_GCIE_LEGACY, then
> > -	 * we support GICv3. Fail attempts to do anything but set
> > that to IMP.
> > -	 */
> > -	if (vgic_is_v3_compat(vcpu->kvm) &&
> > -	    FIELD_GET(ID_AA64PFR0_EL1_GIC_MASK, user_val) !=
> > ID_AA64PFR0_EL1_GIC_IMP)
> > -		return -EINVAL;
> > -
> >  	return set_id_reg(vcpu, rd, user_val);
> >  }
> >  
> 

Re: [PATCH v6 01/39] KVM: arm64: vgic-v3: Drop userspace write sanitization for ID_AA64PFR0.GIC on GICv5

[Jonathan Cameron]

On Thu, 19 Mar 2026 11:35:32 +0000
Sascha Bischoff <Sascha.Bischoff@arm.com> wrote:

> On Thu, 2026-03-19 at 10:02 +0000, Jonathan Cameron wrote:
> > On Tue, 17 Mar 2026 11:40:13 +0000
> > Sascha Bischoff <Sascha.Bischoff@arm.com> wrote:
> >   
> > > Drop a check that blocked userspace writes to ID_AA64PFR0_EL1 for
> > > writes that set the GIC field to 0 (NI) on GICv5 hosts. There is no
> > > such check for GICv3 native systems, and having inconsistent
> > > behaviour
> > > both complicates the logic and risks breaking existing userspace
> > > software that expects to be able to write the register.
> > > 
> > > This means that userspace is now able to create a GICv3 guest on
> > > GICv5
> > > hosts, and disable the guest from seeing that it has a GICv3. This  
> > 
> > Just to clarify this is removing a check on a nonsensical setup?
> > I'm not against it if that simplifies things but I couldn't quite
> > parse the description.  
> 
> Effectively, we were being more strict when running with GICv3 on a
> GICv5 host than when running natively on a GICv3 host. This by itself
> wasn't too big an issue, but it can cause existing software break if it
> relies on being able to hide GICv3 this way (for whatever reason...),
> and somewhat breaks the portability story.
> 
> Moreover, we test these sorts of things in the selftests. If a virtual
> GICv3 is created but then userspace comes along and zeros the feature
> bits (so, hides the feature), we expect the FGU infrastructure to take
> over to undef registers/instructions related to that feature. So, in
> this case, rather than letting userspace hide the virtual GICv3 from
> the guest, we instead stopped it from hiding it.
> 
You have me at self tests of the infrastructure.  That bit I get :)

> Does that make some sort of sense?
> 
> Thanks,
> Sascha
> 
> >   
> > > matches the already existing behaviour for GICv3-native VMs.
> > > 
> > > Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
> > > ---
> > >  arch/arm64/kvm/sys_regs.c | 8 --------
> > >  1 file changed, 8 deletions(-)
> > > 
> > > diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
> > > index 1b4cacb6e918a..4b9f4e5d946b1 100644
> > > --- a/arch/arm64/kvm/sys_regs.c
> > > +++ b/arch/arm64/kvm/sys_regs.c
> > > @@ -2177,14 +2177,6 @@ static int set_id_aa64pfr0_el1(struct
> > > kvm_vcpu *vcpu,
> > >  	    (vcpu_has_nv(vcpu) && !FIELD_GET(ID_AA64PFR0_EL1_EL2,
> > > user_val)))
> > >  		return -EINVAL;
> > >  
> > > -	/*
> > > -	 * If we are running on a GICv5 host and support
> > > FEAT_GCIE_LEGACY, then
> > > -	 * we support GICv3. Fail attempts to do anything but set
> > > that to IMP.
> > > -	 */
> > > -	if (vgic_is_v3_compat(vcpu->kvm) &&
> > > -	    FIELD_GET(ID_AA64PFR0_EL1_GIC_MASK, user_val) !=
> > > ID_AA64PFR0_EL1_GIC_IMP)
> > > -		return -EINVAL;
> > > -
> > >  	return set_id_reg(vcpu, rd, user_val);
> > >  }
> > >    
> >   
> 

[PATCH v6 02/39] KVM: arm64: vgic: Rework vgic_is_v3() and add vgic_host_has_gicvX()

[Sascha Bischoff]

The GIC version checks used to determine host capabilities and guest
configuration have become somewhat conflated (in part due to the
addition of GICv5 support). vgic_is_v3() is a prime example, which
prior to this change has been a combination of guest configuration and
host cabability.

Split out the host capability check from vgic_is_v3(), which now only
checks if the vgic model itself is GICv3. Add two new functions:
vgic_host_has_gicv3() and vgic_host_has_gicv5(). These explicitly
check the host capabilities, i.e., can the host system run a GICvX
guest or not.

The vgic_is_v3() check in vcpu_set_ich_hcr() has been replaced with
vgic_host_has_gicv3() as this only applies on GICv3-capable hardware,
and isn't strictly only applicable for a GICv3 guest (it is actually
vital for vGICv2 on GICv3 hosts).

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
---
 arch/arm64/kvm/sys_regs.c     |  2 +-
 arch/arm64/kvm/vgic/vgic-v3.c |  2 +-
 arch/arm64/kvm/vgic/vgic.h    | 17 +++++++++++++----
 3 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 4b9f4e5d946b1..0acd10e50aaba 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1985,7 +1985,7 @@ static u64 sanitise_id_aa64pfr0_el1(const struct kvm_vcpu *vcpu, u64 val)
 		val |= SYS_FIELD_PREP_ENUM(ID_AA64PFR0_EL1, CSV3, IMP);
 	}
 
-	if (vgic_is_v3(vcpu->kvm)) {
+	if (vgic_host_has_gicv3()) {
 		val &= ~ID_AA64PFR0_EL1_GIC_MASK;
 		val |= SYS_FIELD_PREP_ENUM(ID_AA64PFR0_EL1, GIC, IMP);
 	}
diff --git a/arch/arm64/kvm/vgic/vgic-v3.c b/arch/arm64/kvm/vgic/vgic-v3.c
index 6a355eca19348..9e841e7afd4a7 100644
--- a/arch/arm64/kvm/vgic/vgic-v3.c
+++ b/arch/arm64/kvm/vgic/vgic-v3.c
@@ -499,7 +499,7 @@ void vcpu_set_ich_hcr(struct kvm_vcpu *vcpu)
 {
 	struct vgic_v3_cpu_if *vgic_v3 = &vcpu->arch.vgic_cpu.vgic_v3;
 
-	if (!vgic_is_v3(vcpu->kvm))
+	if (!vgic_host_has_gicv3())
 		return;
 
 	/* Hide GICv3 sysreg if necessary */
diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h
index c9b3bb07e483c..0bb8fa10bb4ef 100644
--- a/arch/arm64/kvm/vgic/vgic.h
+++ b/arch/arm64/kvm/vgic/vgic.h
@@ -454,15 +454,24 @@ void vgic_v3_put_nested(struct kvm_vcpu *vcpu);
 void vgic_v3_handle_nested_maint_irq(struct kvm_vcpu *vcpu);
 void vgic_v3_nested_update_mi(struct kvm_vcpu *vcpu);
 
-static inline bool vgic_is_v3_compat(struct kvm *kvm)
+static inline bool vgic_is_v3(struct kvm *kvm)
+{
+	return kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3;
+}
+
+static inline bool vgic_host_has_gicv3(void)
 {
-	return cpus_have_final_cap(ARM64_HAS_GICV5_CPUIF) &&
+	/*
+	 * Either the host is a native GICv3, or it is GICv5 with
+	 * FEAT_GCIE_LEGACY.
+	 */
+	return kvm_vgic_global_state.type == VGIC_V3 ||
 		kvm_vgic_global_state.has_gcie_v3_compat;
 }
 
-static inline bool vgic_is_v3(struct kvm *kvm)
+static inline bool vgic_host_has_gicv5(void)
 {
-	return kvm_vgic_global_state.type == VGIC_V3 || vgic_is_v3_compat(kvm);
+	return kvm_vgic_global_state.type == VGIC_V5;
 }
 
 int vgic_its_debug_init(struct kvm_device *dev);
-- 
2.34.1

[PATCH v6 03/39] KVM: arm64: Return early from kvm_finalize_sys_regs() if guest has run

[Sascha Bischoff]

If the guest has already run, we have no business finalizing the
system register state - it is too late. Therefore, check early and
bail if the VM has already run.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
---
 arch/arm64/kvm/sys_regs.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 0acd10e50aaba..42c84b7900ff5 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -5659,11 +5659,14 @@ int kvm_finalize_sys_regs(struct kvm_vcpu *vcpu)
 
 	guard(mutex)(&kvm->arch.config_lock);
 
+	if (kvm_vm_has_ran_once(kvm))
+		return 0;
+
 	/*
 	 * This hacks into the ID registers, so only perform it when the
 	 * first vcpu runs, or the kvm_set_vm_id_reg() helper will scream.
 	 */
-	if (!irqchip_in_kernel(kvm) && !kvm_vm_has_ran_once(kvm)) {
+	if (!irqchip_in_kernel(kvm)) {
 		u64 val;
 
 		val = kvm_read_vm_id_reg(kvm, SYS_ID_AA64PFR0_EL1) & ~ID_AA64PFR0_EL1_GIC;
-- 
2.34.1

Re: [PATCH v6 03/39] KVM: arm64: Return early from kvm_finalize_sys_regs() if guest has run

[Jonathan Cameron]

On Tue, 17 Mar 2026 11:40:44 +0000
Sascha Bischoff <Sascha.Bischoff@arm.com> wrote:

> If the guest has already run, we have no business finalizing the
> system register state - it is too late. Therefore, check early and
> bail if the VM has already run.
Given it isn't in the scope below, might be worth calling out that
this is skipping kvm_init_nv_sysregs()  So on non NV setups isn't
changing anything but on those it's indeed skipping setup of system
registers.

Seems correct to me, but is this a fix?  So should it have a fixes tag?


> 
> Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
> ---
>  arch/arm64/kvm/sys_regs.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
> index 0acd10e50aaba..42c84b7900ff5 100644
> --- a/arch/arm64/kvm/sys_regs.c
> +++ b/arch/arm64/kvm/sys_regs.c
> @@ -5659,11 +5659,14 @@ int kvm_finalize_sys_regs(struct kvm_vcpu *vcpu)
>  
>  	guard(mutex)(&kvm->arch.config_lock);
>  
> +	if (kvm_vm_has_ran_once(kvm))
> +		return 0;
> +
>  	/*
>  	 * This hacks into the ID registers, so only perform it when the
>  	 * first vcpu runs, or the kvm_set_vm_id_reg() helper will scream.
>  	 */
> -	if (!irqchip_in_kernel(kvm) && !kvm_vm_has_ran_once(kvm)) {
> +	if (!irqchip_in_kernel(kvm)) {
>  		u64 val;
>  
>  		val = kvm_read_vm_id_reg(kvm, SYS_ID_AA64PFR0_EL1) & ~ID_AA64PFR0_EL1_GIC;

Re: [PATCH v6 03/39] KVM: arm64: Return early from kvm_finalize_sys_regs() if guest has run

[Sascha Bischoff]

On Thu, 2026-03-19 at 10:12 +0000, Jonathan Cameron wrote:
> On Tue, 17 Mar 2026 11:40:44 +0000
> Sascha Bischoff <Sascha.Bischoff@arm.com> wrote:
> 
> > If the guest has already run, we have no business finalizing the
> > system register state - it is too late. Therefore, check early and
> > bail if the VM has already run.
> Given it isn't in the scope below, might be worth calling out that
> this is skipping kvm_init_nv_sysregs()  So on non NV setups isn't
> changing anything but on those it's indeed skipping setup of system
> registers.

I'll add that to the description to make it clearer, thanks!

> 
> Seems correct to me, but is this a fix?  So should it have a fixes
> tag?

I'm not sure it is a fix as such - it is more of an optimisation. While
the call to kvm_init_nv_sysregs() was previously happening irrespective
of the VM having run or not, it was not actually doing anything as kvm-
>arch.sysreg_masks is non-null the second time it is called, and hence
returned early.

Now we just skip calling it altogether if it has already run once.

Thanks,
Sascha

> 
> 
> > 
> > Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
> > ---
> >  arch/arm64/kvm/sys_regs.c | 5 ++++-
> >  1 file changed, 4 insertions(+), 1 deletion(-)
> > 
> > diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
> > index 0acd10e50aaba..42c84b7900ff5 100644
> > --- a/arch/arm64/kvm/sys_regs.c
> > +++ b/arch/arm64/kvm/sys_regs.c
> > @@ -5659,11 +5659,14 @@ int kvm_finalize_sys_regs(struct kvm_vcpu
> > *vcpu)
> >  
> >  	guard(mutex)(&kvm->arch.config_lock);
> >  
> > +	if (kvm_vm_has_ran_once(kvm))
> > +		return 0;
> > +
> >  	/*
> >  	 * This hacks into the ID registers, so only perform it
> > when the
> >  	 * first vcpu runs, or the kvm_set_vm_id_reg() helper will
> > scream.
> >  	 */
> > -	if (!irqchip_in_kernel(kvm) && !kvm_vm_has_ran_once(kvm))
> > {
> > +	if (!irqchip_in_kernel(kvm)) {
> >  		u64 val;
> >  
> >  		val = kvm_read_vm_id_reg(kvm, SYS_ID_AA64PFR0_EL1)
> > & ~ID_AA64PFR0_EL1_GIC;
> 

[PATCH v6 04/39] KVM: arm64: vgic: Split out mapping IRQs and setting irq_ops

[Sascha Bischoff]

Prior to this change, the act of mapping a virtual IRQ to a physical
one also set the irq_ops. Unmapping then reset the irq_ops to NULL. So
far, this has been fine and hasn't caused any major issues.

Now, however, as GICv5 support is being added to KVM, it has become
apparent that conflating mapping/unmapping IRQs and setting/clearing
irq_ops can cause issues. The reason is that the upcoming GICv5
support introduces a set of default irq_ops for PPIs, and removing
this when unmapping will cause things to break rather horribly.

Split out the mapping/unmapping of IRQs from the setting/clearing of
irq_ops. The arch timer code is updated to set the irq_ops following a
successful map. The irq_ops are intentionally not removed again on an
unmap as the only irq_op introduced by the arch timer only takes
effect if the hw bit in struct vgic_irq is set. Therefore, it is safe
to leave this in place, and it avoids additional complexity when GICv5
support is introduced.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
---
 arch/arm64/kvm/arch_timer.c | 32 ++++++++++++++++++-------------
 arch/arm64/kvm/vgic/vgic.c  | 38 +++++++++++++++++++++++++++++++------
 include/kvm/arm_vgic.h      |  5 ++++-
 3 files changed, 55 insertions(+), 20 deletions(-)

diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c
index 600f250753b45..1f536dd5978d4 100644
--- a/arch/arm64/kvm/arch_timer.c
+++ b/arch/arm64/kvm/arch_timer.c
@@ -740,14 +740,17 @@ static void kvm_timer_vcpu_load_nested_switch(struct kvm_vcpu *vcpu,
 
 		ret = kvm_vgic_map_phys_irq(vcpu,
 					    map->direct_vtimer->host_timer_irq,
-					    timer_irq(map->direct_vtimer),
-					    &arch_timer_irq_ops);
-		WARN_ON_ONCE(ret);
+					    timer_irq(map->direct_vtimer));
+		if (!WARN_ON_ONCE(ret))
+			kvm_vgic_set_irq_ops(vcpu, timer_irq(map->direct_vtimer),
+					     &arch_timer_irq_ops);
+
 		ret = kvm_vgic_map_phys_irq(vcpu,
 					    map->direct_ptimer->host_timer_irq,
-					    timer_irq(map->direct_ptimer),
-					    &arch_timer_irq_ops);
-		WARN_ON_ONCE(ret);
+					    timer_irq(map->direct_ptimer));
+		if (!WARN_ON_ONCE(ret))
+			kvm_vgic_set_irq_ops(vcpu, timer_irq(map->direct_ptimer),
+					     &arch_timer_irq_ops);
 	}
 }
 
@@ -1565,20 +1568,23 @@ int kvm_timer_enable(struct kvm_vcpu *vcpu)
 
 	ret = kvm_vgic_map_phys_irq(vcpu,
 				    map.direct_vtimer->host_timer_irq,
-				    timer_irq(map.direct_vtimer),
-				    &arch_timer_irq_ops);
+				    timer_irq(map.direct_vtimer));
 	if (ret)
 		return ret;
 
+	kvm_vgic_set_irq_ops(vcpu, timer_irq(map.direct_vtimer),
+			     &arch_timer_irq_ops);
+
 	if (map.direct_ptimer) {
 		ret = kvm_vgic_map_phys_irq(vcpu,
 					    map.direct_ptimer->host_timer_irq,
-					    timer_irq(map.direct_ptimer),
-					    &arch_timer_irq_ops);
-	}
+					    timer_irq(map.direct_ptimer));
+		if (ret)
+			return ret;
 
-	if (ret)
-		return ret;
+		kvm_vgic_set_irq_ops(vcpu, timer_irq(map.direct_ptimer),
+				     &arch_timer_irq_ops);
+	}
 
 no_vgic:
 	timer->enabled = 1;
diff --git a/arch/arm64/kvm/vgic/vgic.c b/arch/arm64/kvm/vgic/vgic.c
index e22b79cfff965..e37c640d74bcf 100644
--- a/arch/arm64/kvm/vgic/vgic.c
+++ b/arch/arm64/kvm/vgic/vgic.c
@@ -553,10 +553,38 @@ int kvm_vgic_inject_irq(struct kvm *kvm, struct kvm_vcpu *vcpu,
 	return 0;
 }
 
+void kvm_vgic_set_irq_ops(struct kvm_vcpu *vcpu, u32 vintid,
+			 struct irq_ops *ops)
+{
+	struct vgic_irq *irq = vgic_get_vcpu_irq(vcpu, vintid);
+
+	BUG_ON(!irq);
+
+	scoped_guard(raw_spinlock_irqsave, &irq->irq_lock)
+	{
+		irq->ops = ops;
+	}
+
+	vgic_put_irq(vcpu->kvm, irq);
+}
+
+void kvm_vgic_clear_irq_ops(struct kvm_vcpu *vcpu, u32 vintid)
+{
+	struct vgic_irq *irq = vgic_get_vcpu_irq(vcpu, vintid);
+
+	BUG_ON(!irq);
+
+	scoped_guard(raw_spinlock_irqsave, &irq->irq_lock)
+	{
+		irq->ops = NULL;
+	}
+
+	vgic_put_irq(vcpu->kvm, irq);
+}
+
 /* @irq->irq_lock must be held */
 static int kvm_vgic_map_irq(struct kvm_vcpu *vcpu, struct vgic_irq *irq,
-			    unsigned int host_irq,
-			    struct irq_ops *ops)
+			    unsigned int host_irq)
 {
 	struct irq_desc *desc;
 	struct irq_data *data;
@@ -576,7 +604,6 @@ static int kvm_vgic_map_irq(struct kvm_vcpu *vcpu, struct vgic_irq *irq,
 	irq->hw = true;
 	irq->host_irq = host_irq;
 	irq->hwintid = data->hwirq;
-	irq->ops = ops;
 	return 0;
 }
 
@@ -585,11 +612,10 @@ static inline void kvm_vgic_unmap_irq(struct vgic_irq *irq)
 {
 	irq->hw = false;
 	irq->hwintid = 0;
-	irq->ops = NULL;
 }
 
 int kvm_vgic_map_phys_irq(struct kvm_vcpu *vcpu, unsigned int host_irq,
-			  u32 vintid, struct irq_ops *ops)
+			  u32 vintid)
 {
 	struct vgic_irq *irq = vgic_get_vcpu_irq(vcpu, vintid);
 	unsigned long flags;
@@ -598,7 +624,7 @@ int kvm_vgic_map_phys_irq(struct kvm_vcpu *vcpu, unsigned int host_irq,
 	BUG_ON(!irq);
 
 	raw_spin_lock_irqsave(&irq->irq_lock, flags);
-	ret = kvm_vgic_map_irq(vcpu, irq, host_irq, ops);
+	ret = kvm_vgic_map_irq(vcpu, irq, host_irq);
 	raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
 	vgic_put_irq(vcpu->kvm, irq);
 
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index f2eafc65bbf4c..46262d1433bca 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -397,8 +397,11 @@ void kvm_vgic_init_cpu_hardware(void);
 
 int kvm_vgic_inject_irq(struct kvm *kvm, struct kvm_vcpu *vcpu,
 			unsigned int intid, bool level, void *owner);
+void kvm_vgic_set_irq_ops(struct kvm_vcpu *vcpu, u32 vintid,
+			  struct irq_ops *ops);
+void kvm_vgic_clear_irq_ops(struct kvm_vcpu *vcpu, u32 vintid);
 int kvm_vgic_map_phys_irq(struct kvm_vcpu *vcpu, unsigned int host_irq,
-			  u32 vintid, struct irq_ops *ops);
+			  u32 vintid);
 int kvm_vgic_unmap_phys_irq(struct kvm_vcpu *vcpu, unsigned int vintid);
 int kvm_vgic_get_map(struct kvm_vcpu *vcpu, unsigned int vintid);
 bool kvm_vgic_map_is_active(struct kvm_vcpu *vcpu, unsigned int vintid);
-- 
2.34.1

Re: [PATCH v6 04/39] KVM: arm64: vgic: Split out mapping IRQs and setting irq_ops

[Marc Zyngier]

On Tue, 17 Mar 2026 11:40:59 +0000,
Sascha Bischoff <Sascha.Bischoff@arm.com> wrote:
> 
> Prior to this change, the act of mapping a virtual IRQ to a physical
> one also set the irq_ops. Unmapping then reset the irq_ops to NULL. So
> far, this has been fine and hasn't caused any major issues.
> 
> Now, however, as GICv5 support is being added to KVM, it has become
> apparent that conflating mapping/unmapping IRQs and setting/clearing
> irq_ops can cause issues. The reason is that the upcoming GICv5
> support introduces a set of default irq_ops for PPIs, and removing
> this when unmapping will cause things to break rather horribly.
> 
> Split out the mapping/unmapping of IRQs from the setting/clearing of
> irq_ops. The arch timer code is updated to set the irq_ops following a
> successful map. The irq_ops are intentionally not removed again on an
> unmap as the only irq_op introduced by the arch timer only takes
> effect if the hw bit in struct vgic_irq is set. Therefore, it is safe
> to leave this in place, and it avoids additional complexity when GICv5
> support is introduced.
> 
> Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
> ---
>  arch/arm64/kvm/arch_timer.c | 32 ++++++++++++++++++-------------
>  arch/arm64/kvm/vgic/vgic.c  | 38 +++++++++++++++++++++++++++++++------
>  include/kvm/arm_vgic.h      |  5 ++++-
>  3 files changed, 55 insertions(+), 20 deletions(-)
> 
> diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c
> index 600f250753b45..1f536dd5978d4 100644
> --- a/arch/arm64/kvm/arch_timer.c
> +++ b/arch/arm64/kvm/arch_timer.c
> @@ -740,14 +740,17 @@ static void kvm_timer_vcpu_load_nested_switch(struct kvm_vcpu *vcpu,
>  
>  		ret = kvm_vgic_map_phys_irq(vcpu,
>  					    map->direct_vtimer->host_timer_irq,
> -					    timer_irq(map->direct_vtimer),
> -					    &arch_timer_irq_ops);
> -		WARN_ON_ONCE(ret);
> +					    timer_irq(map->direct_vtimer));
> +		if (!WARN_ON_ONCE(ret))
> +			kvm_vgic_set_irq_ops(vcpu, timer_irq(map->direct_vtimer),
> +					     &arch_timer_irq_ops);
> +
>  		ret = kvm_vgic_map_phys_irq(vcpu,
>  					    map->direct_ptimer->host_timer_irq,
> -					    timer_irq(map->direct_ptimer),
> -					    &arch_timer_irq_ops);
> -		WARN_ON_ONCE(ret);
> +					    timer_irq(map->direct_ptimer));
> +		if (!WARN_ON_ONCE(ret))
> +			kvm_vgic_set_irq_ops(vcpu, timer_irq(map->direct_ptimer),
> +					     &arch_timer_irq_ops);

Do we really need this eager setting of ops? Given that nothing seems
to clear them, why can't we just set the ops at vcpu init time? Given
that this is a pretty hot path (on each exception/exception return
between L2 and L1), the least we do here, the better.

>  	}
>  }
>  
> @@ -1565,20 +1568,23 @@ int kvm_timer_enable(struct kvm_vcpu *vcpu)
>  
>  	ret = kvm_vgic_map_phys_irq(vcpu,
>  				    map.direct_vtimer->host_timer_irq,
> -				    timer_irq(map.direct_vtimer),
> -				    &arch_timer_irq_ops);
> +				    timer_irq(map.direct_vtimer));
>  	if (ret)
>  		return ret;
>  
> +	kvm_vgic_set_irq_ops(vcpu, timer_irq(map.direct_vtimer),
> +			     &arch_timer_irq_ops);
> +
>  	if (map.direct_ptimer) {
>  		ret = kvm_vgic_map_phys_irq(vcpu,
>  					    map.direct_ptimer->host_timer_irq,
> -					    timer_irq(map.direct_ptimer),
> -					    &arch_timer_irq_ops);
> -	}
> +					    timer_irq(map.direct_ptimer));
> +		if (ret)
> +			return ret;
>  
> -	if (ret)
> -		return ret;
> +		kvm_vgic_set_irq_ops(vcpu, timer_irq(map.direct_ptimer),
> +				     &arch_timer_irq_ops);
> +	}

which would mean moving this to kvm_timer_vcpu_init().

>  
>  no_vgic:
>  	timer->enabled = 1;
> diff --git a/arch/arm64/kvm/vgic/vgic.c b/arch/arm64/kvm/vgic/vgic.c
> index e22b79cfff965..e37c640d74bcf 100644
> --- a/arch/arm64/kvm/vgic/vgic.c
> +++ b/arch/arm64/kvm/vgic/vgic.c
> @@ -553,10 +553,38 @@ int kvm_vgic_inject_irq(struct kvm *kvm, struct kvm_vcpu *vcpu,
>  	return 0;
>  }
>  
> +void kvm_vgic_set_irq_ops(struct kvm_vcpu *vcpu, u32 vintid,
> +			 struct irq_ops *ops)
> +{
> +	struct vgic_irq *irq = vgic_get_vcpu_irq(vcpu, vintid);
> +
> +	BUG_ON(!irq);
> +
> +	scoped_guard(raw_spinlock_irqsave, &irq->irq_lock)
> +	{
> +		irq->ops = ops;
> +	}

nit: opening brace in the wrong spot, and overall not useful. This
could simply be written as:

	scoped_guard(raw_spinlock_irqsave, &irq->irq_lock)
		irq->ops = ops;

> +
> +	vgic_put_irq(vcpu->kvm, irq);
> +}
> +
> +void kvm_vgic_clear_irq_ops(struct kvm_vcpu *vcpu, u32 vintid)
> +{
> +	struct vgic_irq *irq = vgic_get_vcpu_irq(vcpu, vintid);
> +
> +	BUG_ON(!irq);
> +
> +	scoped_guard(raw_spinlock_irqsave, &irq->irq_lock)
> +	{
> +		irq->ops = NULL;
> +	}
> +
> +	vgic_put_irq(vcpu->kvm, irq);
> +}
> +

nit: that could also be written as:

void kvm_vgic_clear_irq_ops(struct kvm_vcpu *vcpu, u32 vintid)
{
	kvm_vgic_set_irq_ops(vcpu, vintid, NULL);
}

I can fix all of it when applying if that works for you.

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.

Re: [PATCH v6 04/39] KVM: arm64: vgic: Split out mapping IRQs and setting irq_ops

[Sascha Bischoff]

On Tue, 2026-03-17 at 16:00 +0000, Marc Zyngier wrote:
> On Tue, 17 Mar 2026 11:40:59 +0000,
> Sascha Bischoff <Sascha.Bischoff@arm.com> wrote:
> > 
> > Prior to this change, the act of mapping a virtual IRQ to a
> > physical
> > one also set the irq_ops. Unmapping then reset the irq_ops to NULL.
> > So
> > far, this has been fine and hasn't caused any major issues.
> > 
> > Now, however, as GICv5 support is being added to KVM, it has become
> > apparent that conflating mapping/unmapping IRQs and
> > setting/clearing
> > irq_ops can cause issues. The reason is that the upcoming GICv5
> > support introduces a set of default irq_ops for PPIs, and removing
> > this when unmapping will cause things to break rather horribly.
> > 
> > Split out the mapping/unmapping of IRQs from the setting/clearing
> > of
> > irq_ops. The arch timer code is updated to set the irq_ops
> > following a
> > successful map. The irq_ops are intentionally not removed again on
> > an
> > unmap as the only irq_op introduced by the arch timer only takes
> > effect if the hw bit in struct vgic_irq is set. Therefore, it is
> > safe
> > to leave this in place, and it avoids additional complexity when
> > GICv5
> > support is introduced.
> > 
> > Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
> > ---
> >  arch/arm64/kvm/arch_timer.c | 32 ++++++++++++++++++-------------
> >  arch/arm64/kvm/vgic/vgic.c  | 38 +++++++++++++++++++++++++++++++--
> > ----
> >  include/kvm/arm_vgic.h      |  5 ++++-
> >  3 files changed, 55 insertions(+), 20 deletions(-)
> > 
> > diff --git a/arch/arm64/kvm/arch_timer.c
> > b/arch/arm64/kvm/arch_timer.c
> > index 600f250753b45..1f536dd5978d4 100644
> > --- a/arch/arm64/kvm/arch_timer.c
> > +++ b/arch/arm64/kvm/arch_timer.c
> > @@ -740,14 +740,17 @@ static void
> > kvm_timer_vcpu_load_nested_switch(struct kvm_vcpu *vcpu,
> >  
> >  		ret = kvm_vgic_map_phys_irq(vcpu,
> >  					    map->direct_vtimer-
> > >host_timer_irq,
> > -					    timer_irq(map-
> > >direct_vtimer),
> > -					    &arch_timer_irq_ops);
> > -		WARN_ON_ONCE(ret);
> > +					    timer_irq(map-
> > >direct_vtimer));
> > +		if (!WARN_ON_ONCE(ret))
> > +			kvm_vgic_set_irq_ops(vcpu, timer_irq(map-
> > >direct_vtimer),
> > +					     &arch_timer_irq_ops);
> > +
> >  		ret = kvm_vgic_map_phys_irq(vcpu,
> >  					    map->direct_ptimer-
> > >host_timer_irq,
> > -					    timer_irq(map-
> > >direct_ptimer),
> > -					    &arch_timer_irq_ops);
> > -		WARN_ON_ONCE(ret);
> > +					    timer_irq(map-
> > >direct_ptimer));
> > +		if (!WARN_ON_ONCE(ret))
> > +			kvm_vgic_set_irq_ops(vcpu, timer_irq(map-
> > >direct_ptimer),
> > +					     &arch_timer_irq_ops);
> 
> Do we really need this eager setting of ops? Given that nothing seems
> to clear them, why can't we just set the ops at vcpu init time? Given
> that this is a pretty hot path (on each exception/exception return
> between L2 and L1), the least we do here, the better.

Hmm, I think you're right. When making this change, I was trying to
preserve the existing behaviour so set the irq_ops for each map call.
However, as you say nothing is clearing the ops (as things stand, at
least), so that does indeed make sense to do IMO.

> 
> >  	}
> >  }
> >  
> > @@ -1565,20 +1568,23 @@ int kvm_timer_enable(struct kvm_vcpu *vcpu)
> >  
> >  	ret = kvm_vgic_map_phys_irq(vcpu,
> >  				    map.direct_vtimer-
> > >host_timer_irq,
> > -				    timer_irq(map.direct_vtimer),
> > -				    &arch_timer_irq_ops);
> > +				    timer_irq(map.direct_vtimer));
> >  	if (ret)
> >  		return ret;
> >  
> > +	kvm_vgic_set_irq_ops(vcpu, timer_irq(map.direct_vtimer),
> > +			     &arch_timer_irq_ops);
> > +
> >  	if (map.direct_ptimer) {
> >  		ret = kvm_vgic_map_phys_irq(vcpu,
> >  					    map.direct_ptimer-
> > >host_timer_irq,
> > -					   
> > timer_irq(map.direct_ptimer),
> > -					    &arch_timer_irq_ops);
> > -	}
> > +					   
> > timer_irq(map.direct_ptimer));
> > +		if (ret)
> > +			return ret;
> >  
> > -	if (ret)
> > -		return ret;
> > +		kvm_vgic_set_irq_ops(vcpu,
> > timer_irq(map.direct_ptimer),
> > +				     &arch_timer_irq_ops);
> > +	}
> 
> which would mean moving this to kvm_timer_vcpu_init().

This, however, is not quite that simple.

It turns out that we actually call kvm_timer_vcpu_init() before
kvm_vgic_vcpu_init() from kvm_arch_vcpu_create(), meaning that we don't
have the private IRQs allocated.

Is there a good reason that the timer (and PMU) are initialised prior
to initialising the CPU?

I've tried making this chang, and once I reorder the timer and vcpu
initialisation I can confirm that things work with and without nested.

> 
> >  
> >  no_vgic:
> >  	timer->enabled = 1;
> > diff --git a/arch/arm64/kvm/vgic/vgic.c
> > b/arch/arm64/kvm/vgic/vgic.c
> > index e22b79cfff965..e37c640d74bcf 100644
> > --- a/arch/arm64/kvm/vgic/vgic.c
> > +++ b/arch/arm64/kvm/vgic/vgic.c
> > @@ -553,10 +553,38 @@ int kvm_vgic_inject_irq(struct kvm *kvm,
> > struct kvm_vcpu *vcpu,
> >  	return 0;
> >  }
> >  
> > +void kvm_vgic_set_irq_ops(struct kvm_vcpu *vcpu, u32 vintid,
> > +			 struct irq_ops *ops)
> > +{
> > +	struct vgic_irq *irq = vgic_get_vcpu_irq(vcpu, vintid);
> > +
> > +	BUG_ON(!irq);
> > +
> > +	scoped_guard(raw_spinlock_irqsave, &irq->irq_lock)
> > +	{
> > +		irq->ops = ops;
> > +	}
> 
> nit: opening brace in the wrong spot, and overall not useful. This
> could simply be written as:
> 
> 	scoped_guard(raw_spinlock_irqsave, &irq->irq_lock)
> 		irq->ops = ops;

Argh, sorry that slipped through!

> 
> > +
> > +	vgic_put_irq(vcpu->kvm, irq);
> > +}
> > +
> > +void kvm_vgic_clear_irq_ops(struct kvm_vcpu *vcpu, u32 vintid)
> > +{
> > +	struct vgic_irq *irq = vgic_get_vcpu_irq(vcpu, vintid);
> > +
> > +	BUG_ON(!irq);
> > +
> > +	scoped_guard(raw_spinlock_irqsave, &irq->irq_lock)
> > +	{
> > +		irq->ops = NULL;
> > +	}
> > +
> > +	vgic_put_irq(vcpu->kvm, irq);
> > +}
> > +
> 
> nit: that could also be written as:
> 
> void kvm_vgic_clear_irq_ops(struct kvm_vcpu *vcpu, u32 vintid)
> {
> 	kvm_vgic_set_irq_ops(vcpu, vintid, NULL);
> }

Ah, that is indeed cleaner.

> 
> I can fix all of it when applying if that works for you.

If you're happy to do that, that is great! Do note what I said above
regarding the order of vcpu and timer init!

Thanks,
Sascha

> 
> Thanks,
> 
> 	M.
> 

[PATCH v6 05/39] arm64/sysreg: Add remaining GICv5 ICC_ & ICH_ sysregs for KVM support

[Sascha Bischoff]

Add the GICv5 system registers required to support native GICv5 guests
with KVM. Many of the GICv5 sysregs have already been added as part of
the host GICv5 driver, keeping this set relatively small. The
registers added in this change complete the set by adding those
required by KVM either directly (ICH_) or indirectly (FGTs for the
ICC_ sysregs).

The following system registers and their fields are added:

	ICC_APR_EL1
	ICC_HPPIR_EL1
	ICC_IAFFIDR_EL1
	ICH_APR_EL2
	ICH_CONTEXTR_EL2
	ICH_PPI_ACTIVER<n>_EL2
	ICH_PPI_DVI<n>_EL2
	ICH_PPI_ENABLER<n>_EL2
	ICH_PPI_PENDR<n>_EL2
	ICH_PPI_PRIORITYR<n>_EL2

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
---
 arch/arm64/tools/sysreg | 480 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 480 insertions(+)

diff --git a/arch/arm64/tools/sysreg b/arch/arm64/tools/sysreg
index 9d1c211080571..51dcca5b2fa6e 100644
--- a/arch/arm64/tools/sysreg
+++ b/arch/arm64/tools/sysreg
@@ -3243,6 +3243,14 @@ UnsignedEnum	3:0	ID_BITS
 EndEnum
 EndSysreg
 
+Sysreg	ICC_HPPIR_EL1	3	0	12	10	3
+Res0	63:33
+Field	32	HPPIV
+Field	31:29	TYPE
+Res0	28:24
+Field	23:0	ID
+EndSysreg
+
 Sysreg	ICC_ICSR_EL1	3	0	12	10	4
 Res0	63:48
 Field	47:32	IAFFID
@@ -3257,6 +3265,11 @@ Field	1	Enabled
 Field	0	F
 EndSysreg
 
+Sysreg	ICC_IAFFIDR_EL1	3	0	12	10	5
+Res0	63:16
+Field	15:0	IAFFID
+EndSysreg
+
 SysregFields	ICC_PPI_ENABLERx_EL1
 Field	63	EN63
 Field	62	EN62
@@ -3663,6 +3676,42 @@ Res0	14:12
 Field	11:0	AFFINITY
 EndSysreg
 
+Sysreg	ICC_APR_EL1	3	1	12	0	0
+Res0	63:32
+Field	31	P31
+Field	30	P30
+Field	29	P29
+Field	28	P28
+Field	27	P27
+Field	26	P26
+Field	25	P25
+Field	24	P24
+Field	23	P23
+Field	22	P22
+Field	21	P21
+Field	20	P20
+Field	19	P19
+Field	18	P18
+Field	17	P17
+Field	16	P16
+Field	15	P15
+Field	14	P14
+Field	13	P13
+Field	12	P12
+Field	11	P11
+Field	10	P10
+Field	9	P9
+Field	8	P8
+Field	7	P7
+Field	6	P6
+Field	5	P5
+Field	4	P4
+Field	3	P3
+Field	2	P2
+Field	1	P1
+Field	0	P0
+EndSysreg
+
 Sysreg	ICC_CR0_EL1	3	1	12	0	1
 Res0	63:39
 Field	38	PID
@@ -4687,6 +4736,42 @@ Field	31:16	PhyPARTID29
 Field	15:0	PhyPARTID28
 EndSysreg
 
+Sysreg	ICH_APR_EL2	3	4	12	8	4
+Res0	63:32
+Field	31	P31
+Field	30	P30
+Field	29	P29
+Field	28	P28
+Field	27	P27
+Field	26	P26
+Field	25	P25
+Field	24	P24
+Field	23	P23
+Field	22	P22
+Field	21	P21
+Field	20	P20
+Field	19	P19
+Field	18	P18
+Field	17	P17
+Field	16	P16
+Field	15	P15
+Field	14	P14
+Field	13	P13
+Field	12	P12
+Field	11	P11
+Field	10	P10
+Field	9	P9
+Field	8	P8
+Field	7	P7
+Field	6	P6
+Field	5	P5
+Field	4	P4
+Field	3	P3
+Field	2	P2
+Field	1	P1
+Field	0	P0
+EndSysreg
+
 Sysreg	ICH_HFGRTR_EL2	3	4	12	9	4
 Res0	63:21
 Field	20	ICC_PPI_ACTIVERn_EL1
@@ -4735,6 +4820,306 @@ Field	1	GICCDDIS
 Field	0	GICCDEN
 EndSysreg
 
+SysregFields	ICH_PPI_DVIRx_EL2
+Field	63	DVI63
+Field	62	DVI62
+Field	61	DVI61
+Field	60	DVI60
+Field	59	DVI59
+Field	58	DVI58
+Field	57	DVI57
+Field	56	DVI56
+Field	55	DVI55
+Field	54	DVI54
+Field	53	DVI53
+Field	52	DVI52
+Field	51	DVI51
+Field	50	DVI50
+Field	49	DVI49
+Field	48	DVI48
+Field	47	DVI47
+Field	46	DVI46
+Field	45	DVI45
+Field	44	DVI44
+Field	43	DVI43
+Field	42	DVI42
+Field	41	DVI41
+Field	40	DVI40
+Field	39	DVI39
+Field	38	DVI38
+Field	37	DVI37
+Field	36	DVI36
+Field	35	DVI35
+Field	34	DVI34
+Field	33	DVI33
+Field	32	DVI32
+Field	31	DVI31
+Field	30	DVI30
+Field	29	DVI29
+Field	28	DVI28
+Field	27	DVI27
+Field	26	DVI26
+Field	25	DVI25
+Field	24	DVI24
+Field	23	DVI23
+Field	22	DVI22
+Field	21	DVI21
+Field	20	DVI20
+Field	19	DVI19
+Field	18	DVI18
+Field	17	DVI17
+Field	16	DVI16
+Field	15	DVI15
+Field	14	DVI14
+Field	13	DVI13
+Field	12	DVI12
+Field	11	DVI11
+Field	10	DVI10
+Field	9	DVI9
+Field	8	DVI8
+Field	7	DVI7
+Field	6	DVI6
+Field	5	DVI5
+Field	4	DVI4
+Field	3	DVI3
+Field	2	DVI2
+Field	1	DVI1
+Field	0	DVI0
+EndSysregFields
+
+Sysreg	ICH_PPI_DVIR0_EL2	3	4	12	10	0
+Fields ICH_PPI_DVIx_EL2
+EndSysreg
+
+Sysreg	ICH_PPI_DVIR1_EL2	3	4	12	10	1
+Fields ICH_PPI_DVIx_EL2
+EndSysreg
+
+SysregFields	ICH_PPI_ENABLERx_EL2
+Field	63	EN63
+Field	62	EN62
+Field	61	EN61
+Field	60	EN60
+Field	59	EN59
+Field	58	EN58
+Field	57	EN57
+Field	56	EN56
+Field	55	EN55
+Field	54	EN54
+Field	53	EN53
+Field	52	EN52
+Field	51	EN51
+Field	50	EN50
+Field	49	EN49
+Field	48	EN48
+Field	47	EN47
+Field	46	EN46
+Field	45	EN45
+Field	44	EN44
+Field	43	EN43
+Field	42	EN42
+Field	41	EN41
+Field	40	EN40
+Field	39	EN39
+Field	38	EN38
+Field	37	EN37
+Field	36	EN36
+Field	35	EN35
+Field	34	EN34
+Field	33	EN33
+Field	32	EN32
+Field	31	EN31
+Field	30	EN30
+Field	29	EN29
+Field	28	EN28
+Field	27	EN27
+Field	26	EN26
+Field	25	EN25
+Field	24	EN24
+Field	23	EN23
+Field	22	EN22
+Field	21	EN21
+Field	20	EN20
+Field	19	EN19
+Field	18	EN18
+Field	17	EN17
+Field	16	EN16
+Field	15	EN15
+Field	14	EN14
+Field	13	EN13
+Field	12	EN12
+Field	11	EN11
+Field	10	EN10
+Field	9	EN9
+Field	8	EN8
+Field	7	EN7
+Field	6	EN6
+Field	5	EN5
+Field	4	EN4
+Field	3	EN3
+Field	2	EN2
+Field	1	EN1
+Field	0	EN0
+EndSysregFields
+
+Sysreg	ICH_PPI_ENABLER0_EL2	3	4	12	10	2
+Fields ICH_PPI_ENABLERx_EL2
+EndSysreg
+
+Sysreg	ICH_PPI_ENABLER1_EL2	3	4	12	10	3
+Fields ICH_PPI_ENABLERx_EL2
+EndSysreg
+
+SysregFields	ICH_PPI_PENDRx_EL2
+Field	63	PEND63
+Field	62	PEND62
+Field	61	PEND61
+Field	60	PEND60
+Field	59	PEND59
+Field	58	PEND58
+Field	57	PEND57
+Field	56	PEND56
+Field	55	PEND55
+Field	54	PEND54
+Field	53	PEND53
+Field	52	PEND52
+Field	51	PEND51
+Field	50	PEND50
+Field	49	PEND49
+Field	48	PEND48
+Field	47	PEND47
+Field	46	PEND46
+Field	45	PEND45
+Field	44	PEND44
+Field	43	PEND43
+Field	42	PEND42
+Field	41	PEND41
+Field	40	PEND40
+Field	39	PEND39
+Field	38	PEND38
+Field	37	PEND37
+Field	36	PEND36
+Field	35	PEND35
+Field	34	PEND34
+Field	33	PEND33
+Field	32	PEND32
+Field	31	PEND31
+Field	30	PEND30
+Field	29	PEND29
+Field	28	PEND28
+Field	27	PEND27
+Field	26	PEND26
+Field	25	PEND25
+Field	24	PEND24
+Field	23	PEND23
+Field	22	PEND22
+Field	21	PEND21
+Field	20	PEND20
+Field	19	PEND19
+Field	18	PEND18
+Field	17	PEND17
+Field	16	PEND16
+Field	15	PEND15
+Field	14	PEND14
+Field	13	PEND13
+Field	12	PEND12
+Field	11	PEND11
+Field	10	PEND10
+Field	9	PEND9
+Field	8	PEND8
+Field	7	PEND7
+Field	6	PEND6
+Field	5	PEND5
+Field	4	PEND4
+Field	3	PEND3
+Field	2	PEND2
+Field	1	PEND1
+Field	0	PEND0
+EndSysregFields
+
+Sysreg	ICH_PPI_PENDR0_EL2	3	4	12	10	4
+Fields ICH_PPI_PENDRx_EL2
+EndSysreg
+
+Sysreg	ICH_PPI_PENDR1_EL2	3	4	12	10	5
+Fields ICH_PPI_PENDRx_EL2
+EndSysreg
+
+SysregFields	ICH_PPI_ACTIVERx_EL2
+Field	63	ACTIVE63
+Field	62	ACTIVE62
+Field	61	ACTIVE61
+Field	60	ACTIVE60
+Field	59	ACTIVE59
+Field	58	ACTIVE58
+Field	57	ACTIVE57
+Field	56	ACTIVE56
+Field	55	ACTIVE55
+Field	54	ACTIVE54
+Field	53	ACTIVE53
+Field	52	ACTIVE52
+Field	51	ACTIVE51
+Field	50	ACTIVE50
+Field	49	ACTIVE49
+Field	48	ACTIVE48
+Field	47	ACTIVE47
+Field	46	ACTIVE46
+Field	45	ACTIVE45
+Field	44	ACTIVE44
+Field	43	ACTIVE43
+Field	42	ACTIVE42
+Field	41	ACTIVE41
+Field	40	ACTIVE40
+Field	39	ACTIVE39
+Field	38	ACTIVE38
+Field	37	ACTIVE37
+Field	36	ACTIVE36
+Field	35	ACTIVE35
+Field	34	ACTIVE34
+Field	33	ACTIVE33
+Field	32	ACTIVE32
+Field	31	ACTIVE31
+Field	30	ACTIVE30
+Field	29	ACTIVE29
+Field	28	ACTIVE28
+Field	27	ACTIVE27
+Field	26	ACTIVE26
+Field	25	ACTIVE25
+Field	24	ACTIVE24
+Field	23	ACTIVE23
+Field	22	ACTIVE22
+Field	21	ACTIVE21
+Field	20	ACTIVE20
+Field	19	ACTIVE19
+Field	18	ACTIVE18
+Field	17	ACTIVE17
+Field	16	ACTIVE16
+Field	15	ACTIVE15
+Field	14	ACTIVE14
+Field	13	ACTIVE13
+Field	12	ACTIVE12
+Field	11	ACTIVE11
+Field	10	ACTIVE10
+Field	9	ACTIVE9
+Field	8	ACTIVE8
+Field	7	ACTIVE7
+Field	6	ACTIVE6
+Field	5	ACTIVE5
+Field	4	ACTIVE4
+Field	3	ACTIVE3
+Field	2	ACTIVE2
+Field	1	ACTIVE1
+Field	0	ACTIVE0
+EndSysregFields
+
+Sysreg	ICH_PPI_ACTIVER0_EL2	3	4	12	10	6
+Fields ICH_PPI_ACTIVERx_EL2
+EndSysreg
+
+Sysreg	ICH_PPI_ACTIVER1_EL2	3	4	12	10	7
+Fields ICH_PPI_ACTIVERx_EL2
+EndSysreg
+
 Sysreg	ICH_HCR_EL2	3	4	12	11	0
 Res0	63:32
 Field	31:27	EOIcount
@@ -4789,6 +5174,18 @@ Field	1	V3
 Field	0	En
 EndSysreg
 
+Sysreg	ICH_CONTEXTR_EL2	3	4	12	11	6
+Field	63	V
+Field	62	F
+Field	61	IRICHPPIDIS
+Field	60	DB
+Field	59:55	DBPM
+Res0	54:48
+Field	47:32	VPE
+Res0	31:16
+Field	15:0	VM
+EndSysreg
+
 Sysreg	ICH_VMCR_EL2	3	4	12	11	7
 Prefix	FEAT_GCIE
 Res0	63:32
@@ -4810,6 +5207,89 @@ Field	1	VENG1
 Field	0	VENG0
 EndSysreg
 
+SysregFields	ICH_PPI_PRIORITYRx_EL2
+Res0	63:61
+Field	60:56	Priority7
+Res0	55:53
+Field	52:48	Priority6
+Res0	47:45
+Field	44:40	Priority5
+Res0	39:37
+Field	36:32	Priority4
+Res0	31:29
+Field	28:24	Priority3
+Res0	23:21
+Field	20:16	Priority2
+Res0	15:13
+Field	12:8	Priority1
+Res0	7:5
+Field	4:0	Priority0
+EndSysregFields
+
+Sysreg	ICH_PPI_PRIORITYR0_EL2	3	4	12	14	0
+Fields	ICH_PPI_PRIORITYRx_EL2
+EndSysreg
+
+Sysreg	ICH_PPI_PRIORITYR1_EL2	3	4	12	14	1
+Fields	ICH_PPI_PRIORITYRx_EL2
+EndSysreg
+
+Sysreg	ICH_PPI_PRIORITYR2_EL2	3	4	12	14	2
+Fields	ICH_PPI_PRIORITYRx_EL2
+EndSysreg
+
+Sysreg	ICH_PPI_PRIORITYR3_EL2	3	4	12	14	3
+Fields	ICH_PPI_PRIORITYRx_EL2
+EndSysreg
+
+Sysreg	ICH_PPI_PRIORITYR4_EL2	3	4	12	14	4
+Fields	ICH_PPI_PRIORITYRx_EL2
+EndSysreg
+
+Sysreg	ICH_PPI_PRIORITYR5_EL2	3	4	12	14	5
+Fields	ICH_PPI_PRIORITYRx_EL2
+EndSysreg
+
+Sysreg	ICH_PPI_PRIORITYR6_EL2	3	4	12	14	6
+Fields	ICH_PPI_PRIORITYRx_EL2
+EndSysreg
+
+Sysreg	ICH_PPI_PRIORITYR7_EL2	3	4	12	14	7
+Fields	ICH_PPI_PRIORITYRx_EL2
+EndSysreg
+
+Sysreg	ICH_PPI_PRIORITYR8_EL2	3	4	12	15	0
+Fields	ICH_PPI_PRIORITYRx_EL2
+EndSysreg
+
+Sysreg	ICH_PPI_PRIORITYR9_EL2	3	4	12	15	1
+Fields	ICH_PPI_PRIORITYRx_EL2
+EndSysreg
+
+Sysreg	ICH_PPI_PRIORITYR10_EL2	3	4	12	15	2
+Fields	ICH_PPI_PRIORITYRx_EL2
+EndSysreg
+
+Sysreg	ICH_PPI_PRIORITYR11_EL2	3	4	12	15	3
+Fields	ICH_PPI_PRIORITYRx_EL2
+EndSysreg
+
+Sysreg	ICH_PPI_PRIORITYR12_EL2	3	4	12	15	4
+Fields	ICH_PPI_PRIORITYRx_EL2
+EndSysreg
+
+Sysreg	ICH_PPI_PRIORITYR13_EL2	3	4	12	15	5
+Fields	ICH_PPI_PRIORITYRx_EL2
+EndSysreg
+
+Sysreg	ICH_PPI_PRIORITYR14_EL2	3	4	12	15	6
+Fields	ICH_PPI_PRIORITYRx_EL2
+EndSysreg
+
+Sysreg	ICH_PPI_PRIORITYR15_EL2	3	4	12	15	7
+Fields	ICH_PPI_PRIORITYRx_EL2
+EndSysreg
+
 Sysreg	CONTEXTIDR_EL2	3	4	13	0	1
 Fields	CONTEXTIDR_ELx
 EndSysreg
-- 
2.34.1

[PATCH v6 06/39] arm64/sysreg: Add GICR CDNMIA encoding

[Sascha Bischoff]

The encoding for the GICR CDNMIA system instruction is thus far unused
(and shall remain unused for the time being). However, in order to
plumb the FGTs into KVM correctly, KVM needs to be made aware of the
encoding of this system instruction.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
---
 arch/arm64/include/asm/sysreg.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index f4436ecc630cd..938cdb248f83c 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -1052,6 +1052,7 @@
 #define GICV5_OP_GIC_CDPRI		sys_insn(1, 0, 12, 1, 2)
 #define GICV5_OP_GIC_CDRCFG		sys_insn(1, 0, 12, 1, 5)
 #define GICV5_OP_GICR_CDIA		sys_insn(1, 0, 12, 3, 0)
+#define GICV5_OP_GICR_CDNMIA		sys_insn(1, 0, 12, 3, 1)
 
 /* Definitions for GIC CDAFF */
 #define GICV5_GIC_CDAFF_IAFFID_MASK	GENMASK_ULL(47, 32)
@@ -1098,6 +1099,12 @@
 #define GICV5_GIC_CDIA_TYPE_MASK	GENMASK_ULL(31, 29)
 #define GICV5_GIC_CDIA_ID_MASK		GENMASK_ULL(23, 0)
 
+/* Definitions for GICR CDNMIA */
+#define GICV5_GICR_CDNMIA_VALID_MASK	BIT_ULL(32)
+#define GICV5_GICR_CDNMIA_VALID(r)	FIELD_GET(GICV5_GICR_CDNMIA_VALID_MASK, r)
+#define GICV5_GICR_CDNMIA_TYPE_MASK	GENMASK_ULL(31, 29)
+#define GICV5_GICR_CDNMIA_ID_MASK	GENMASK_ULL(23, 0)
+
 #define gicr_insn(insn)			read_sysreg_s(GICV5_OP_GICR_##insn)
 #define gic_insn(v, insn)		write_sysreg_s(v, GICV5_OP_GIC_##insn)
 
-- 
2.34.1

[PATCH v6 07/39] KVM: arm64: gic-v5: Add ARM_VGIC_V5 device to KVM headers

[Sascha Bischoff]

This is the base GICv5 device which is to be used with the
KVM_CREATE_DEVICE ioctl to create a GICv5-based vgic.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
---
 include/uapi/linux/kvm.h       | 2 ++
 tools/include/uapi/linux/kvm.h | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 80364d4dbebb0..d0c0c86059767 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1224,6 +1224,8 @@ enum kvm_device_type {
 #define KVM_DEV_TYPE_LOONGARCH_EIOINTC	KVM_DEV_TYPE_LOONGARCH_EIOINTC
 	KVM_DEV_TYPE_LOONGARCH_PCHPIC,
 #define KVM_DEV_TYPE_LOONGARCH_PCHPIC	KVM_DEV_TYPE_LOONGARCH_PCHPIC
+	KVM_DEV_TYPE_ARM_VGIC_V5,
+#define KVM_DEV_TYPE_ARM_VGIC_V5	KVM_DEV_TYPE_ARM_VGIC_V5
 
 	KVM_DEV_TYPE_MAX,
 
diff --git a/tools/include/uapi/linux/kvm.h b/tools/include/uapi/linux/kvm.h
index 65500f5db3799..713e4360eca00 100644
--- a/tools/include/uapi/linux/kvm.h
+++ b/tools/include/uapi/linux/kvm.h
@@ -1220,6 +1220,8 @@ enum kvm_device_type {
 #define KVM_DEV_TYPE_LOONGARCH_EIOINTC	KVM_DEV_TYPE_LOONGARCH_EIOINTC
 	KVM_DEV_TYPE_LOONGARCH_PCHPIC,
 #define KVM_DEV_TYPE_LOONGARCH_PCHPIC	KVM_DEV_TYPE_LOONGARCH_PCHPIC
+	KVM_DEV_TYPE_ARM_VGIC_V5,
+#define KVM_DEV_TYPE_ARM_VGIC_V5	KVM_DEV_TYPE_ARM_VGIC_V5
 
 	KVM_DEV_TYPE_MAX,
 
-- 
2.34.1

[PATCH v6 08/39] KVM: arm64: gic: Introduce interrupt type helpers

[Sascha Bischoff]

GICv5 has moved from using interrupt ranges for different interrupt
types to using some of the upper bits of the interrupt ID to denote
the interrupt type. This is not compatible with older GICs (which rely
on ranges of interrupts to determine the type), and hence a set of
helpers is introduced. These helpers take a struct kvm*, and use the
vgic model to determine how to interpret the interrupt ID.

Helpers are introduced for PPIs, SPIs, and LPIs. Additionally, a
helper is introduced to determine if an interrupt is private - SGIs
and PPIs for older GICs, and PPIs only for GICv5.

Additionally, vgic_is_v5() is introduced (which unsurpisingly returns
true when running a GICv5 guest), and the existing vgic_is_v3() check
is moved from vgic.h to arm_vgic.h (to live alongside the vgic_is_v5()
one), and has been converted into a macro.

The helpers are plumbed into the core vgic code, as well as the Arch
Timer and PMU code.

There should be no functional changes as part of this change.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
---
 arch/arm64/kvm/arch_timer.c           |   2 +-
 arch/arm64/kvm/pmu-emul.c             |   7 +-
 arch/arm64/kvm/vgic/vgic-kvm-device.c |   2 +-
 arch/arm64/kvm/vgic/vgic.c            |  14 ++--
 arch/arm64/kvm/vgic/vgic.h            |   5 --
 include/kvm/arm_vgic.h                | 102 ++++++++++++++++++++++++--
 6 files changed, 110 insertions(+), 22 deletions(-)

diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c
index 1f536dd5978d4..53312b88c342d 100644
--- a/arch/arm64/kvm/arch_timer.c
+++ b/arch/arm64/kvm/arch_timer.c
@@ -1609,7 +1609,7 @@ int kvm_arm_timer_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
 	if (get_user(irq, uaddr))
 		return -EFAULT;
 
-	if (!(irq_is_ppi(irq)))
+	if (!(irq_is_ppi(vcpu->kvm, irq)))
 		return -EINVAL;
 
 	mutex_lock(&vcpu->kvm->arch.config_lock);
diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c
index 93cc9bbb5cecd..41a3c5dc2bcac 100644
--- a/arch/arm64/kvm/pmu-emul.c
+++ b/arch/arm64/kvm/pmu-emul.c
@@ -939,7 +939,8 @@ int kvm_arm_pmu_v3_enable(struct kvm_vcpu *vcpu)
 		 * number against the dimensions of the vgic and make sure
 		 * it's valid.
 		 */
-		if (!irq_is_ppi(irq) && !vgic_valid_spi(vcpu->kvm, irq))
+		if (!irq_is_ppi(vcpu->kvm, irq) &&
+		    !vgic_valid_spi(vcpu->kvm, irq))
 			return -EINVAL;
 	} else if (kvm_arm_pmu_irq_initialized(vcpu)) {
 		   return -EINVAL;
@@ -991,7 +992,7 @@ static bool pmu_irq_is_valid(struct kvm *kvm, int irq)
 		if (!kvm_arm_pmu_irq_initialized(vcpu))
 			continue;
 
-		if (irq_is_ppi(irq)) {
+		if (irq_is_ppi(vcpu->kvm, irq)) {
 			if (vcpu->arch.pmu.irq_num != irq)
 				return false;
 		} else {
@@ -1142,7 +1143,7 @@ int kvm_arm_pmu_v3_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
 			return -EFAULT;
 
 		/* The PMU overflow interrupt can be a PPI or a valid SPI. */
-		if (!(irq_is_ppi(irq) || irq_is_spi(irq)))
+		if (!(irq_is_ppi(vcpu->kvm, irq) || irq_is_spi(vcpu->kvm, irq)))
 			return -EINVAL;
 
 		if (!pmu_irq_is_valid(kvm, irq))
diff --git a/arch/arm64/kvm/vgic/vgic-kvm-device.c b/arch/arm64/kvm/vgic/vgic-kvm-device.c
index 3d1a776b716d7..b12ba99a423e5 100644
--- a/arch/arm64/kvm/vgic/vgic-kvm-device.c
+++ b/arch/arm64/kvm/vgic/vgic-kvm-device.c
@@ -639,7 +639,7 @@ static int vgic_v3_set_attr(struct kvm_device *dev,
 		if (vgic_initialized(dev->kvm))
 			return -EBUSY;
 
-		if (!irq_is_ppi(val))
+		if (!irq_is_ppi(dev->kvm, val))
 			return -EINVAL;
 
 		dev->kvm->arch.vgic.mi_intid = val;
diff --git a/arch/arm64/kvm/vgic/vgic.c b/arch/arm64/kvm/vgic/vgic.c
index e37c640d74bcf..d95fbf20002f4 100644
--- a/arch/arm64/kvm/vgic/vgic.c
+++ b/arch/arm64/kvm/vgic/vgic.c
@@ -94,7 +94,7 @@ struct vgic_irq *vgic_get_irq(struct kvm *kvm, u32 intid)
 	}
 
 	/* LPIs */
-	if (intid >= VGIC_MIN_LPI)
+	if (irq_is_lpi(kvm, intid))
 		return vgic_get_lpi(kvm, intid);
 
 	return NULL;
@@ -123,7 +123,7 @@ static void vgic_release_lpi_locked(struct vgic_dist *dist, struct vgic_irq *irq
 
 static __must_check bool __vgic_put_irq(struct kvm *kvm, struct vgic_irq *irq)
 {
-	if (irq->intid < VGIC_MIN_LPI)
+	if (!irq_is_lpi(kvm, irq->intid))
 		return false;
 
 	return refcount_dec_and_test(&irq->refcount);
@@ -148,7 +148,7 @@ void vgic_put_irq(struct kvm *kvm, struct vgic_irq *irq)
 	 * Acquire/release it early on lockdep kernels to make locking issues
 	 * in rare release paths a bit more obvious.
 	 */
-	if (IS_ENABLED(CONFIG_LOCKDEP) && irq->intid >= VGIC_MIN_LPI) {
+	if (IS_ENABLED(CONFIG_LOCKDEP) && irq_is_lpi(kvm, irq->intid)) {
 		guard(spinlock_irqsave)(&dist->lpi_xa.xa_lock);
 	}
 
@@ -186,7 +186,7 @@ void vgic_flush_pending_lpis(struct kvm_vcpu *vcpu)
 	raw_spin_lock_irqsave(&vgic_cpu->ap_list_lock, flags);
 
 	list_for_each_entry_safe(irq, tmp, &vgic_cpu->ap_list_head, ap_list) {
-		if (irq->intid >= VGIC_MIN_LPI) {
+		if (irq_is_lpi(vcpu->kvm, irq->intid)) {
 			raw_spin_lock(&irq->irq_lock);
 			list_del(&irq->ap_list);
 			irq->vcpu = NULL;
@@ -521,12 +521,12 @@ int kvm_vgic_inject_irq(struct kvm *kvm, struct kvm_vcpu *vcpu,
 	if (ret)
 		return ret;
 
-	if (!vcpu && intid < VGIC_NR_PRIVATE_IRQS)
+	if (!vcpu && irq_is_private(kvm, intid))
 		return -EINVAL;
 
 	trace_vgic_update_irq_pending(vcpu ? vcpu->vcpu_idx : 0, intid, level);
 
-	if (intid < VGIC_NR_PRIVATE_IRQS)
+	if (irq_is_private(kvm, intid))
 		irq = vgic_get_vcpu_irq(vcpu, intid);
 	else
 		irq = vgic_get_irq(kvm, intid);
@@ -711,7 +711,7 @@ int kvm_vgic_set_owner(struct kvm_vcpu *vcpu, unsigned int intid, void *owner)
 		return -EAGAIN;
 
 	/* SGIs and LPIs cannot be wired up to any device */
-	if (!irq_is_ppi(intid) && !vgic_valid_spi(vcpu->kvm, intid))
+	if (!irq_is_ppi(vcpu->kvm, intid) && !vgic_valid_spi(vcpu->kvm, intid))
 		return -EINVAL;
 
 	irq = vgic_get_vcpu_irq(vcpu, intid);
diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h
index 0bb8fa10bb4ef..f2924f8211974 100644
--- a/arch/arm64/kvm/vgic/vgic.h
+++ b/arch/arm64/kvm/vgic/vgic.h
@@ -454,11 +454,6 @@ void vgic_v3_put_nested(struct kvm_vcpu *vcpu);
 void vgic_v3_handle_nested_maint_irq(struct kvm_vcpu *vcpu);
 void vgic_v3_nested_update_mi(struct kvm_vcpu *vcpu);
 
-static inline bool vgic_is_v3(struct kvm *kvm)
-{
-	return kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3;
-}
-
 static inline bool vgic_host_has_gicv3(void)
 {
 	/*
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 46262d1433bca..b8011b395796d 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -19,6 +19,7 @@
 #include <linux/jump_label.h>
 
 #include <linux/irqchip/arm-gic-v4.h>
+#include <linux/irqchip/arm-gic-v5.h>
 
 #define VGIC_V3_MAX_CPUS	512
 #define VGIC_V2_MAX_CPUS	8
@@ -31,9 +32,88 @@
 #define VGIC_MIN_LPI		8192
 #define KVM_IRQCHIP_NUM_PINS	(1020 - 32)
 
-#define irq_is_ppi(irq) ((irq) >= VGIC_NR_SGIS && (irq) < VGIC_NR_PRIVATE_IRQS)
-#define irq_is_spi(irq) ((irq) >= VGIC_NR_PRIVATE_IRQS && \
-			 (irq) <= VGIC_MAX_SPI)
+#define is_v5_type(t, i)	(FIELD_GET(GICV5_HWIRQ_TYPE, (i)) == (t))
+
+#define __irq_is_sgi(t, i)						\
+	({								\
+		bool __ret;						\
+									\
+		switch (t) {						\
+		case KVM_DEV_TYPE_ARM_VGIC_V5:				\
+			__ret = false;					\
+			break;						\
+		default:						\
+			__ret  = (i) < VGIC_NR_SGIS;			\
+		}							\
+									\
+		__ret;							\
+	})
+
+#define __irq_is_ppi(t, i)						\
+	({								\
+		bool __ret;						\
+									\
+		switch (t) {						\
+		case KVM_DEV_TYPE_ARM_VGIC_V5:				\
+			__ret = is_v5_type(GICV5_HWIRQ_TYPE_PPI, (i));	\
+			break;						\
+		default:						\
+			__ret  = (i) >= VGIC_NR_SGIS;			\
+			__ret &= (i) < VGIC_NR_PRIVATE_IRQS;		\
+		}							\
+									\
+		__ret;							\
+	})
+
+#define __irq_is_spi(t, i)						\
+	({								\
+		bool __ret;						\
+									\
+		switch (t) {						\
+		case KVM_DEV_TYPE_ARM_VGIC_V5:				\
+			__ret = is_v5_type(GICV5_HWIRQ_TYPE_SPI, (i));	\
+			break;						\
+		default:						\
+			__ret  = (i) <= VGIC_MAX_SPI;			\
+			__ret &= (i) >= VGIC_NR_PRIVATE_IRQS;		\
+		}							\
+									\
+		__ret;							\
+	})
+
+#define __irq_is_lpi(t, i)						\
+	({								\
+		bool __ret;						\
+									\
+		switch (t) {						\
+		case KVM_DEV_TYPE_ARM_VGIC_V5:				\
+			__ret = is_v5_type(GICV5_HWIRQ_TYPE_LPI, (i));	\
+			break;						\
+		default:						\
+			__ret  = (i) >= 8192;				\
+		}							\
+									\
+		__ret;							\
+	})
+
+#define irq_is_sgi(k, i) __irq_is_sgi((k)->arch.vgic.vgic_model, i)
+#define irq_is_ppi(k, i) __irq_is_ppi((k)->arch.vgic.vgic_model, i)
+#define irq_is_spi(k, i) __irq_is_spi((k)->arch.vgic.vgic_model, i)
+#define irq_is_lpi(k, i) __irq_is_lpi((k)->arch.vgic.vgic_model, i)
+
+#define irq_is_private(k, i) (irq_is_ppi(k, i) || irq_is_sgi(k, i))
+
+#define vgic_v5_get_hwirq_id(x) FIELD_GET(GICV5_HWIRQ_ID, (x))
+#define vgic_v5_set_hwirq_id(x) FIELD_PREP(GICV5_HWIRQ_ID, (x))
+
+#define __vgic_v5_set_type(t) (FIELD_PREP(GICV5_HWIRQ_TYPE, GICV5_HWIRQ_TYPE_##t))
+#define vgic_v5_make_ppi(x) (__vgic_v5_set_type(PPI) | vgic_v5_set_hwirq_id(x))
+#define vgic_v5_make_spi(x) (__vgic_v5_set_type(SPI) | vgic_v5_set_hwirq_id(x))
+#define vgic_v5_make_lpi(x) (__vgic_v5_set_type(LPI) | vgic_v5_set_hwirq_id(x))
+
+#define __vgic_is_v(k, v) ((k)->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V##v)
+#define vgic_is_v3(k) (__vgic_is_v(k, 3))
+#define vgic_is_v5(k) (__vgic_is_v(k, 5))
 
 enum vgic_type {
 	VGIC_V2,		/* Good ol' GICv2 */
@@ -417,8 +497,20 @@ u64 vgic_v3_get_misr(struct kvm_vcpu *vcpu);
 
 #define irqchip_in_kernel(k)	(!!((k)->arch.vgic.in_kernel))
 #define vgic_initialized(k)	((k)->arch.vgic.initialized)
-#define vgic_valid_spi(k, i)	(((i) >= VGIC_NR_PRIVATE_IRQS) && \
-			((i) < (k)->arch.vgic.nr_spis + VGIC_NR_PRIVATE_IRQS))
+#define vgic_valid_spi(k, i)						\
+	({								\
+		bool __ret = irq_is_spi(k, i);				\
+									\
+		switch ((k)->arch.vgic.vgic_model) {			\
+		case KVM_DEV_TYPE_ARM_VGIC_V5:				\
+			__ret &= FIELD_GET(GICV5_HWIRQ_ID, i) < (k)->arch.vgic.nr_spis; \
+			break;						\
+		default:						\
+			__ret &= (i) < ((k)->arch.vgic.nr_spis + VGIC_NR_PRIVATE_IRQS); \
+		}							\
+									\
+		__ret;							\
+	})
 
 bool kvm_vcpu_has_pending_irqs(struct kvm_vcpu *vcpu);
 void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu);
-- 
2.34.1

[PATCH v6 09/39] KVM: arm64: gic-v5: Add Arm copyright header

[Sascha Bischoff]

This header was mistakenly omitted during the creation of this
file. Add it now. Better late than never.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
---
 arch/arm64/kvm/vgic/vgic-v5.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm64/kvm/vgic/vgic-v5.c b/arch/arm64/kvm/vgic/vgic-v5.c
index 331651087e2c7..9d9aa5774e634 100644
--- a/arch/arm64/kvm/vgic/vgic-v5.c
+++ b/arch/arm64/kvm/vgic/vgic-v5.c
@@ -1,4 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2025, 2026 Arm Ltd.
+ */
 
 #include <kvm/arm_vgic.h>
 #include <linux/irqchip/arm-vgic-info.h>
-- 
2.34.1

[PATCH v6 10/39] KVM: arm64: gic-v5: Detect implemented PPIs on boot

[Sascha Bischoff]

As part of booting the system and initialising KVM, create and
populate a mask of the implemented PPIs. This mask allows future PPI
operations (such as save/restore or state, or syncing back into the
shadow state) to only consider PPIs that are actually implemented on
the host.

The set of implemented virtual PPIs matches the set of implemented
physical PPIs for a GICv5 host. Therefore, this mask represents all
PPIs that could ever by used by a GICv5-based guest on a specific
host, albeit pre-filtered by what we support in KVM (see next
paragraph).

Only architected PPIs are currently supported in KVM with
GICv5. Moreover, as KVM only supports a subset of all possible PPIS
(Timers, PMU, GICv5 SW_PPI) the PPI mask only includes these PPIs, if
present. The timers are always assumed to be present; if we have KVM
we have EL2, which means that we have the EL1 & EL2 Timer PPIs. If we
have a PMU (v3), then the PMUIRQ is present. The GICv5 SW_PPI is
always assumed to be present.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
---
 arch/arm64/kvm/vgic/vgic-v5.c      | 31 ++++++++++++++++++++++++++++++
 include/kvm/arm_vgic.h             | 13 +++++++++++++
 include/linux/irqchip/arm-gic-v5.h | 22 +++++++++++++++++++++
 3 files changed, 66 insertions(+)

diff --git a/arch/arm64/kvm/vgic/vgic-v5.c b/arch/arm64/kvm/vgic/vgic-v5.c
index 9d9aa5774e634..cf8382a954bbc 100644
--- a/arch/arm64/kvm/vgic/vgic-v5.c
+++ b/arch/arm64/kvm/vgic/vgic-v5.c
@@ -4,10 +4,39 @@
  */
 
 #include <kvm/arm_vgic.h>
+
+#include <linux/bitops.h>
 #include <linux/irqchip/arm-vgic-info.h>
 
 #include "vgic.h"
 
+static struct vgic_v5_ppi_caps ppi_caps;
+
+/*
+ * Not all PPIs are guaranteed to be implemented for GICv5. Deterermine which
+ * ones are, and generate a mask.
+ */
+static void vgic_v5_get_implemented_ppis(void)
+{
+	if (!cpus_have_final_cap(ARM64_HAS_GICV5_CPUIF))
+		return;
+
+	/*
+	 * If we have KVM, we have EL2, which means that we have support for the
+	 * EL1 and EL2 Physical & Virtual timers.
+	 */
+	__assign_bit(GICV5_ARCH_PPI_CNTHP, ppi_caps.impl_ppi_mask, 1);
+	__assign_bit(GICV5_ARCH_PPI_CNTV, ppi_caps.impl_ppi_mask, 1);
+	__assign_bit(GICV5_ARCH_PPI_CNTHV, ppi_caps.impl_ppi_mask, 1);
+	__assign_bit(GICV5_ARCH_PPI_CNTP, ppi_caps.impl_ppi_mask, 1);
+
+	/* The SW_PPI should be available */
+	__assign_bit(GICV5_ARCH_PPI_SW_PPI, ppi_caps.impl_ppi_mask, 1);
+
+	/* The PMUIRQ is available if we have the PMU */
+	__assign_bit(GICV5_ARCH_PPI_PMUIRQ, ppi_caps.impl_ppi_mask, system_supports_pmuv3());
+}
+
 /*
  * Probe for a vGICv5 compatible interrupt controller, returning 0 on success.
  * Currently only supports GICv3-based VMs on a GICv5 host, and hence only
@@ -18,6 +47,8 @@ int vgic_v5_probe(const struct gic_kvm_info *info)
 	u64 ich_vtr_el2;
 	int ret;
 
+	vgic_v5_get_implemented_ppis();
+
 	if (!cpus_have_final_cap(ARM64_HAS_GICV5_LEGACY))
 		return -ENODEV;
 
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index b8011b395796d..0fabeabedd6d7 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -32,6 +32,14 @@
 #define VGIC_MIN_LPI		8192
 #define KVM_IRQCHIP_NUM_PINS	(1020 - 32)
 
+/*
+ * GICv5 supports 128 PPIs, but only the first 64 are architected. We only
+ * support the timers and PMU in KVM, both of which are architected. Rather than
+ * handling twice the state, we instead opt to only support the architected set
+ * in KVM for now. At a future stage, this can be bumped up to 128, if required.
+ */
+#define VGIC_V5_NR_PRIVATE_IRQS	64
+
 #define is_v5_type(t, i)	(FIELD_GET(GICV5_HWIRQ_TYPE, (i)) == (t))
 
 #define __irq_is_sgi(t, i)						\
@@ -420,6 +428,11 @@ struct vgic_v3_cpu_if {
 	unsigned int used_lrs;
 };
 
+/* What PPI capabilities does a GICv5 host have */
+struct vgic_v5_ppi_caps {
+	DECLARE_BITMAP(impl_ppi_mask, VGIC_V5_NR_PRIVATE_IRQS);
+};
+
 struct vgic_cpu {
 	/* CPU vif control registers for world switch */
 	union {
diff --git a/include/linux/irqchip/arm-gic-v5.h b/include/linux/irqchip/arm-gic-v5.h
index b78488df6c989..b1566a7c93ecb 100644
--- a/include/linux/irqchip/arm-gic-v5.h
+++ b/include/linux/irqchip/arm-gic-v5.h
@@ -24,6 +24,28 @@
 #define GICV5_HWIRQ_TYPE_LPI		UL(0x2)
 #define GICV5_HWIRQ_TYPE_SPI		UL(0x3)
 
+/*
+ * Architected PPIs
+ */
+#define GICV5_ARCH_PPI_S_DB_PPI		0x0
+#define GICV5_ARCH_PPI_RL_DB_PPI	0x1
+#define GICV5_ARCH_PPI_NS_DB_PPI	0x2
+#define GICV5_ARCH_PPI_SW_PPI		0x3
+#define GICV5_ARCH_PPI_HACDBSIRQ	0xf
+#define GICV5_ARCH_PPI_CNTHVS		0x13
+#define GICV5_ARCH_PPI_CNTHPS		0x14
+#define GICV5_ARCH_PPI_PMBIRQ		0x15
+#define GICV5_ARCH_PPI_COMMIRQ		0x16
+#define GICV5_ARCH_PPI_PMUIRQ		0x17
+#define GICV5_ARCH_PPI_CTIIRQ		0x18
+#define GICV5_ARCH_PPI_GICMNT		0x19
+#define GICV5_ARCH_PPI_CNTHP		0x1a
+#define GICV5_ARCH_PPI_CNTV		0x1b
+#define GICV5_ARCH_PPI_CNTHV		0x1c
+#define GICV5_ARCH_PPI_CNTPS		0x1d
+#define GICV5_ARCH_PPI_CNTP		0x1e
+#define GICV5_ARCH_PPI_TRBIRQ		0x1f
+
 /*
  * Tables attributes
  */
-- 
2.34.1

[PATCH v6 11/39] KVM: arm64: gic-v5: Sanitize ID_AA64PFR2_EL1.GCIE

[Sascha Bischoff]

Add in a sanitization function for ID_AA64PFR2_EL1, preserving the
already-present behaviour for the FPMR, MTEFAR, and MTESTOREONLY
fields. Add sanitisation for the GCIE field, which is set to IMP if
the host supports a GICv5 guest and NI, otherwise.

Extend the sanitisation that takes place in kvm_vgic_create() to zero
the ID_AA64PFR2.GCIE field when a non-GICv5 GIC is created. More
importantly, move this sanitisation to a separate function,
kvm_vgic_finalize_sysregs(), and call it from kvm_finalize_sys_regs().

We are required to finalize the GIC and GCIE fields a second time in
kvm_finalize_sys_regs() due to how QEMU blindly reads out then
verbatim restores the system register state. This avoids the issue
where both the GCIE and GIC features are marked as present (an
architecturally invalid combination), and hence guests fall over. See
the comment in kvm_finalize_sys_regs() for more details.

Overall, the following happens:

* Before an irqchip is created, FEAT_GCIE is presented if the host
  supports GICv5-based guests.
* Once an irqchip is created, all other supported irqchips are hidden
  from the guest; system register state reflects the guest's irqchip.
* Userspace is allowed to set invalid irqchip feature combinations in
  the system registers, but...
* ...invalid combinations are removed a second time prior to the first
  run of the guest, and things hopefully just work.

All of this extra work is required to make sure that "legacy" GICv3
guests based on QEMU transparently work on compatible GICv5 hosts
without modification.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
---
 arch/arm64/kvm/sys_regs.c       | 70 +++++++++++++++++++++++++++++----
 arch/arm64/kvm/vgic/vgic-init.c | 49 ++++++++++++++++-------
 include/kvm/arm_vgic.h          |  1 +
 3 files changed, 98 insertions(+), 22 deletions(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 42c84b7900ff5..140cf35f4eeb4 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1758,6 +1758,7 @@ static u8 pmuver_to_perfmon(u8 pmuver)
 
 static u64 sanitise_id_aa64pfr0_el1(const struct kvm_vcpu *vcpu, u64 val);
 static u64 sanitise_id_aa64pfr1_el1(const struct kvm_vcpu *vcpu, u64 val);
+static u64 sanitise_id_aa64pfr2_el1(const struct kvm_vcpu *vcpu, u64 val);
 static u64 sanitise_id_aa64dfr0_el1(const struct kvm_vcpu *vcpu, u64 val);
 
 /* Read a sanitised cpufeature ID register by sys_reg_desc */
@@ -1783,10 +1784,7 @@ static u64 __kvm_read_sanitised_id_reg(const struct kvm_vcpu *vcpu,
 		val = sanitise_id_aa64pfr1_el1(vcpu, val);
 		break;
 	case SYS_ID_AA64PFR2_EL1:
-		val &= ID_AA64PFR2_EL1_FPMR |
-			(kvm_has_mte(vcpu->kvm) ?
-			 ID_AA64PFR2_EL1_MTEFAR | ID_AA64PFR2_EL1_MTESTOREONLY :
-			 0);
+		val = sanitise_id_aa64pfr2_el1(vcpu, val);
 		break;
 	case SYS_ID_AA64ISAR1_EL1:
 		if (!vcpu_has_ptrauth(vcpu))
@@ -2027,6 +2025,23 @@ static u64 sanitise_id_aa64pfr1_el1(const struct kvm_vcpu *vcpu, u64 val)
 	return val;
 }
 
+static u64 sanitise_id_aa64pfr2_el1(const struct kvm_vcpu *vcpu, u64 val)
+{
+	val &= ID_AA64PFR2_EL1_FPMR |
+	       ID_AA64PFR2_EL1_MTEFAR |
+	       ID_AA64PFR2_EL1_MTESTOREONLY;
+
+	if (!kvm_has_mte(vcpu->kvm)) {
+		val &= ~ID_AA64PFR2_EL1_MTEFAR;
+		val &= ~ID_AA64PFR2_EL1_MTESTOREONLY;
+	}
+
+	if (vgic_host_has_gicv5())
+		val |= SYS_FIELD_PREP_ENUM(ID_AA64PFR2_EL1, GCIE, IMP);
+
+	return val;
+}
+
 static u64 sanitise_id_aa64dfr0_el1(const struct kvm_vcpu *vcpu, u64 val)
 {
 	val = ID_REG_LIMIT_FIELD_ENUM(val, ID_AA64DFR0_EL1, DebugVer, V8P8);
@@ -2216,6 +2231,12 @@ static int set_id_aa64pfr1_el1(struct kvm_vcpu *vcpu,
 	return set_id_reg(vcpu, rd, user_val);
 }
 
+static int set_id_aa64pfr2_el1(struct kvm_vcpu *vcpu,
+			       const struct sys_reg_desc *rd, u64 user_val)
+{
+	return set_id_reg(vcpu, rd, user_val);
+}
+
 /*
  * Allow userspace to de-feature a stage-2 translation granule but prevent it
  * from claiming the impossible.
@@ -3197,10 +3218,11 @@ static const struct sys_reg_desc sys_reg_descs[] = {
 				       ID_AA64PFR1_EL1_RES0 |
 				       ID_AA64PFR1_EL1_MPAM_frac |
 				       ID_AA64PFR1_EL1_MTE)),
-	ID_WRITABLE(ID_AA64PFR2_EL1,
-		    ID_AA64PFR2_EL1_FPMR |
-		    ID_AA64PFR2_EL1_MTEFAR |
-		    ID_AA64PFR2_EL1_MTESTOREONLY),
+	ID_FILTERED(ID_AA64PFR2_EL1, id_aa64pfr2_el1,
+		    ~(ID_AA64PFR2_EL1_FPMR |
+		      ID_AA64PFR2_EL1_MTEFAR |
+		      ID_AA64PFR2_EL1_MTESTOREONLY |
+		      ID_AA64PFR2_EL1_GCIE)),
 	ID_UNALLOCATED(4,3),
 	ID_WRITABLE(ID_AA64ZFR0_EL1, ~ID_AA64ZFR0_EL1_RES0),
 	ID_HIDDEN(ID_AA64SMFR0_EL1),
@@ -5671,8 +5693,40 @@ int kvm_finalize_sys_regs(struct kvm_vcpu *vcpu)
 
 		val = kvm_read_vm_id_reg(kvm, SYS_ID_AA64PFR0_EL1) & ~ID_AA64PFR0_EL1_GIC;
 		kvm_set_vm_id_reg(kvm, SYS_ID_AA64PFR0_EL1, val);
+		val = kvm_read_vm_id_reg(kvm, SYS_ID_AA64PFR2_EL1) & ~ID_AA64PFR2_EL1_GCIE;
+		kvm_set_vm_id_reg(kvm, SYS_ID_AA64PFR2_EL1, val);
 		val = kvm_read_vm_id_reg(kvm, SYS_ID_PFR1_EL1) & ~ID_PFR1_EL1_GIC;
 		kvm_set_vm_id_reg(kvm, SYS_ID_PFR1_EL1, val);
+	} else {
+		/*
+		 * Certain userspace software - QEMU - samples the system
+		 * register state without creating an irqchip, then blindly
+		 * restores the state prior to running the final guest. This
+		 * means that it restores the virtualization & emulation
+		 * capabilities of the host system, rather than something that
+		 * reflects the final guest state. Moreover, it checks that the
+		 * state was "correctly" restored (i.e., verbatim), bailing if
+		 * it isn't, so masking off invalid state isn't an option.
+		 *
+		 * On GICv5 hardware that supports FEAT_GCIE_LEGACY we can run
+		 * both GICv3- and GICv5-based guests. Therefore, we initially
+		 * present both ID_AA64PFR0.GIC and ID_AA64PFR2.GCIE as IMP to
+		 * reflect that userspace can create EITHER a vGICv3 or a
+		 * vGICv5. This is an architecturally invalid combination, of
+		 * course. Once an in-kernel GIC is created, the sysreg state is
+		 * updated to reflect the actual, valid configuration.
+		 *
+		 * Setting both the GIC and GCIE features to IMP unsurprisingly
+		 * results in guests falling over, and hence we need to fix up
+		 * this mess in KVM. Before running for the first time we yet
+		 * again ensure that the GIC and GCIE fields accurately reflect
+		 * the actual hardware the guest should see.
+		 *
+		 * This hack allows legacy QEMU-based GICv3 guests to run
+		 * unmodified on compatible GICv5 hosts, and avoids the inverse
+		 * problem for GICv5-based guests in the future.
+		 */
+		kvm_vgic_finalize_idregs(kvm);
 	}
 
 	if (vcpu_has_nv(vcpu)) {
diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c
index e9b8b5fc480c7..e1be9c5ada7b3 100644
--- a/arch/arm64/kvm/vgic/vgic-init.c
+++ b/arch/arm64/kvm/vgic/vgic-init.c
@@ -71,7 +71,6 @@ static int vgic_allocate_private_irqs_locked(struct kvm_vcpu *vcpu, u32 type);
 int kvm_vgic_create(struct kvm *kvm, u32 type)
 {
 	struct kvm_vcpu *vcpu;
-	u64 aa64pfr0, pfr1;
 	unsigned long i;
 	int ret;
 
@@ -145,19 +144,11 @@ int kvm_vgic_create(struct kvm *kvm, u32 type)
 	kvm->arch.vgic.implementation_rev = KVM_VGIC_IMP_REV_LATEST;
 	kvm->arch.vgic.vgic_dist_base = VGIC_ADDR_UNDEF;
 
-	aa64pfr0 = kvm_read_vm_id_reg(kvm, SYS_ID_AA64PFR0_EL1) & ~ID_AA64PFR0_EL1_GIC;
-	pfr1 = kvm_read_vm_id_reg(kvm, SYS_ID_PFR1_EL1) & ~ID_PFR1_EL1_GIC;
-
-	if (type == KVM_DEV_TYPE_ARM_VGIC_V2) {
-		kvm->arch.vgic.vgic_cpu_base = VGIC_ADDR_UNDEF;
-	} else {
-		INIT_LIST_HEAD(&kvm->arch.vgic.rd_regions);
-		aa64pfr0 |= SYS_FIELD_PREP_ENUM(ID_AA64PFR0_EL1, GIC, IMP);
-		pfr1 |= SYS_FIELD_PREP_ENUM(ID_PFR1_EL1, GIC, GICv3);
-	}
-
-	kvm_set_vm_id_reg(kvm, SYS_ID_AA64PFR0_EL1, aa64pfr0);
-	kvm_set_vm_id_reg(kvm, SYS_ID_PFR1_EL1, pfr1);
+	/*
+	 * We've now created the GIC. Update the system register state
+	 * to accurately reflect what we've created.
+	 */
+	kvm_vgic_finalize_idregs(kvm);
 
 	kvm_for_each_vcpu(i, vcpu, kvm) {
 		ret = vgic_allocate_private_irqs_locked(vcpu, type);
@@ -617,6 +608,36 @@ int kvm_vgic_map_resources(struct kvm *kvm)
 	return ret;
 }
 
+void kvm_vgic_finalize_idregs(struct kvm *kvm)
+{
+	u32 type = kvm->arch.vgic.vgic_model;
+	u64 aa64pfr0, aa64pfr2, pfr1;
+
+	aa64pfr0 = kvm_read_vm_id_reg(kvm, SYS_ID_AA64PFR0_EL1) & ~ID_AA64PFR0_EL1_GIC;
+	aa64pfr2 = kvm_read_vm_id_reg(kvm, SYS_ID_AA64PFR2_EL1) & ~ID_AA64PFR2_EL1_GCIE;
+	pfr1 = kvm_read_vm_id_reg(kvm, SYS_ID_PFR1_EL1) & ~ID_PFR1_EL1_GIC;
+
+	switch (type) {
+	case KVM_DEV_TYPE_ARM_VGIC_V2:
+		kvm->arch.vgic.vgic_cpu_base = VGIC_ADDR_UNDEF;
+		break;
+	case KVM_DEV_TYPE_ARM_VGIC_V3:
+		INIT_LIST_HEAD(&kvm->arch.vgic.rd_regions);
+		aa64pfr0 |= SYS_FIELD_PREP_ENUM(ID_AA64PFR0_EL1, GIC, IMP);
+		pfr1 |= SYS_FIELD_PREP_ENUM(ID_PFR1_EL1, GIC, GICv3);
+		break;
+	case KVM_DEV_TYPE_ARM_VGIC_V5:
+		aa64pfr2 |= SYS_FIELD_PREP_ENUM(ID_AA64PFR2_EL1, GCIE, IMP);
+		break;
+	default:
+		WARN_ONCE(1, "Unknown VGIC type!!!\n");
+	}
+
+	kvm_set_vm_id_reg(kvm, SYS_ID_AA64PFR0_EL1, aa64pfr0);
+	kvm_set_vm_id_reg(kvm, SYS_ID_AA64PFR2_EL1, aa64pfr2);
+	kvm_set_vm_id_reg(kvm, SYS_ID_PFR1_EL1, pfr1);
+}
+
 /* GENERIC PROBE */
 
 void kvm_vgic_cpu_up(void)
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 0fabeabedd6d7..24969fa8d02d6 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -485,6 +485,7 @@ int kvm_vgic_create(struct kvm *kvm, u32 type);
 void kvm_vgic_destroy(struct kvm *kvm);
 void kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu);
 int kvm_vgic_map_resources(struct kvm *kvm);
+void kvm_vgic_finalize_idregs(struct kvm *kvm);
 int kvm_vgic_hyp_init(void);
 void kvm_vgic_init_cpu_hardware(void);
 
-- 
2.34.1

Re: [PATCH v6 11/39] KVM: arm64: gic-v5: Sanitize ID_AA64PFR2_EL1.GCIE

[Jonathan Cameron]

On Tue, 17 Mar 2026 11:42:47 +0000
Sascha Bischoff <Sascha.Bischoff@arm.com> wrote:

> Add in a sanitization function for ID_AA64PFR2_EL1, preserving the
> already-present behaviour for the FPMR, MTEFAR, and MTESTOREONLY
> fields. Add sanitisation for the GCIE field, which is set to IMP if
> the host supports a GICv5 guest and NI, otherwise.
> 
> Extend the sanitisation that takes place in kvm_vgic_create() to zero
> the ID_AA64PFR2.GCIE field when a non-GICv5 GIC is created. More
> importantly, move this sanitisation to a separate function,
> kvm_vgic_finalize_sysregs(), and call it from kvm_finalize_sys_regs().
> 
> We are required to finalize the GIC and GCIE fields a second time in
> kvm_finalize_sys_regs() due to how QEMU blindly reads out then
> verbatim restores the system register state. This avoids the issue
> where both the GCIE and GIC features are marked as present (an
> architecturally invalid combination), and hence guests fall over. See
> the comment in kvm_finalize_sys_regs() for more details.
> 
> Overall, the following happens:
> 
> * Before an irqchip is created, FEAT_GCIE is presented if the host
>   supports GICv5-based guests.
> * Once an irqchip is created, all other supported irqchips are hidden
>   from the guest; system register state reflects the guest's irqchip.
> * Userspace is allowed to set invalid irqchip feature combinations in
>   the system registers, but...
> * ...invalid combinations are removed a second time prior to the first
>   run of the guest, and things hopefully just work.
> 
> All of this extra work is required to make sure that "legacy" GICv3
> guests based on QEMU transparently work on compatible GICv5 hosts
> without modification.
> 
> Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>

Kind of trivial but I'd have split this into a factor out of the helper
(no functional changes) then the additional stuff.
Meh, it's simple enough to perhaps not be worth the effort.

Anyhow, one comment on what to me looks like a slightly inconsistent approach
to sanitization. Anyhow, not that important as code is easy enough to read
and if anything over restricts (which could be relaxed if that ever becomes
relevant).

Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>


> ---
>  arch/arm64/kvm/sys_regs.c       | 70 +++++++++++++++++++++++++++++----
>  arch/arm64/kvm/vgic/vgic-init.c | 49 ++++++++++++++++-------
>  include/kvm/arm_vgic.h          |  1 +
>  3 files changed, 98 insertions(+), 22 deletions(-)
> 
> diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
> index 42c84b7900ff5..140cf35f4eeb4 100644
> --- a/arch/arm64/kvm/sys_regs.c
> +++ b/arch/arm64/kvm/sys_regs.c
> @@ -1758,6 +1758,7 @@ static u8 pmuver_to_perfmon(u8 pmuver)
>  
>  static u64 sanitise_id_aa64pfr0_el1(const struct kvm_vcpu *vcpu, u64 val);
>  static u64 sanitise_id_aa64pfr1_el1(const struct kvm_vcpu *vcpu, u64 val);
> +static u64 sanitise_id_aa64pfr2_el1(const struct kvm_vcpu *vcpu, u64 val);
>  static u64 sanitise_id_aa64dfr0_el1(const struct kvm_vcpu *vcpu, u64 val);
>  
>  /* Read a sanitised cpufeature ID register by sys_reg_desc */
> @@ -1783,10 +1784,7 @@ static u64 __kvm_read_sanitised_id_reg(const struct kvm_vcpu *vcpu,
>  		val = sanitise_id_aa64pfr1_el1(vcpu, val);
>  		break;
>  	case SYS_ID_AA64PFR2_EL1:
> -		val &= ID_AA64PFR2_EL1_FPMR |
> -			(kvm_has_mte(vcpu->kvm) ?
> -			 ID_AA64PFR2_EL1_MTEFAR | ID_AA64PFR2_EL1_MTESTOREONLY :
> -			 0);
> +		val = sanitise_id_aa64pfr2_el1(vcpu, val);
>  		break;
>  	case SYS_ID_AA64ISAR1_EL1:
>  		if (!vcpu_has_ptrauth(vcpu))
> @@ -2027,6 +2025,23 @@ static u64 sanitise_id_aa64pfr1_el1(const struct kvm_vcpu *vcpu, u64 val)
>  	return val;
>  }
>  
> +static u64 sanitise_id_aa64pfr2_el1(const struct kvm_vcpu *vcpu, u64 val)
> +{
> +	val &= ID_AA64PFR2_EL1_FPMR |
> +	       ID_AA64PFR2_EL1_MTEFAR |
> +	       ID_AA64PFR2_EL1_MTESTOREONLY;

Style wise this feels inconsistent.  For these 3 registers the sanitise simply
clears them if not supported, it doesn't enforce particular values despite
for example MTESTOREONLY only taking values 0 and 1..


> +
> +	if (!kvm_has_mte(vcpu->kvm)) {
> +		val &= ~ID_AA64PFR2_EL1_MTEFAR;
> +		val &= ~ID_AA64PFR2_EL1_MTESTOREONLY;
> +	}
> +
> +	if (vgic_host_has_gicv5())

..but for this one you are forcing a specific value rather than clearing whatever
was there if !vgic_host_has_gicv5()

I don't mind that much though as still obvious what is going on and perhaps
we do need to be careful this takes only a 1 or 0.


> +		val |= SYS_FIELD_PREP_ENUM(ID_AA64PFR2_EL1, GCIE, IMP);
> +
> +	return val;
> +}

Re: [PATCH v6 11/39] KVM: arm64: gic-v5: Sanitize ID_AA64PFR2_EL1.GCIE

[Sascha Bischoff]

On Thu, 2026-03-19 at 10:31 +0000, Jonathan Cameron wrote:
> On Tue, 17 Mar 2026 11:42:47 +0000
> Sascha Bischoff <Sascha.Bischoff@arm.com> wrote:
> 
> > Add in a sanitization function for ID_AA64PFR2_EL1, preserving the
> > already-present behaviour for the FPMR, MTEFAR, and MTESTOREONLY
> > fields. Add sanitisation for the GCIE field, which is set to IMP if
> > the host supports a GICv5 guest and NI, otherwise.
> > 
> > Extend the sanitisation that takes place in kvm_vgic_create() to
> > zero
> > the ID_AA64PFR2.GCIE field when a non-GICv5 GIC is created. More
> > importantly, move this sanitisation to a separate function,
> > kvm_vgic_finalize_sysregs(), and call it from
> > kvm_finalize_sys_regs().
> > 
> > We are required to finalize the GIC and GCIE fields a second time
> > in
> > kvm_finalize_sys_regs() due to how QEMU blindly reads out then
> > verbatim restores the system register state. This avoids the issue
> > where both the GCIE and GIC features are marked as present (an
> > architecturally invalid combination), and hence guests fall over.
> > See
> > the comment in kvm_finalize_sys_regs() for more details.
> > 
> > Overall, the following happens:
> > 
> > * Before an irqchip is created, FEAT_GCIE is presented if the host
> >   supports GICv5-based guests.
> > * Once an irqchip is created, all other supported irqchips are
> > hidden
> >   from the guest; system register state reflects the guest's
> > irqchip.
> > * Userspace is allowed to set invalid irqchip feature combinations
> > in
> >   the system registers, but...
> > * ...invalid combinations are removed a second time prior to the
> > first
> >   run of the guest, and things hopefully just work.
> > 
> > All of this extra work is required to make sure that "legacy" GICv3
> > guests based on QEMU transparently work on compatible GICv5 hosts
> > without modification.
> > 
> > Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
> 
> Kind of trivial but I'd have split this into a factor out of the
> helper
> (no functional changes) then the additional stuff.
> Meh, it's simple enough to perhaps not be worth the effort.
> 
> Anyhow, one comment on what to me looks like a slightly inconsistent
> approach
> to sanitization. Anyhow, not that important as code is easy enough to
> read
> and if anything over restricts (which could be relaxed if that ever
> becomes
> relevant).
> 
> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
> 
> 
> > ---
> >  arch/arm64/kvm/sys_regs.c       | 70
> > +++++++++++++++++++++++++++++----
> >  arch/arm64/kvm/vgic/vgic-init.c | 49 ++++++++++++++++-------
> >  include/kvm/arm_vgic.h          |  1 +
> >  3 files changed, 98 insertions(+), 22 deletions(-)
> > 
> > diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
> > index 42c84b7900ff5..140cf35f4eeb4 100644
> > --- a/arch/arm64/kvm/sys_regs.c
> > +++ b/arch/arm64/kvm/sys_regs.c
> > @@ -1758,6 +1758,7 @@ static u8 pmuver_to_perfmon(u8 pmuver)
> >  
> >  static u64 sanitise_id_aa64pfr0_el1(const struct kvm_vcpu *vcpu,
> > u64 val);
> >  static u64 sanitise_id_aa64pfr1_el1(const struct kvm_vcpu *vcpu,
> > u64 val);
> > +static u64 sanitise_id_aa64pfr2_el1(const struct kvm_vcpu *vcpu,
> > u64 val);
> >  static u64 sanitise_id_aa64dfr0_el1(const struct kvm_vcpu *vcpu,
> > u64 val);
> >  
> >  /* Read a sanitised cpufeature ID register by sys_reg_desc */
> > @@ -1783,10 +1784,7 @@ static u64 __kvm_read_sanitised_id_reg(const
> > struct kvm_vcpu *vcpu,
> >  		val = sanitise_id_aa64pfr1_el1(vcpu, val);
> >  		break;
> >  	case SYS_ID_AA64PFR2_EL1:
> > -		val &= ID_AA64PFR2_EL1_FPMR |
> > -			(kvm_has_mte(vcpu->kvm) ?
> > -			 ID_AA64PFR2_EL1_MTEFAR |
> > ID_AA64PFR2_EL1_MTESTOREONLY :
> > -			 0);
> > +		val = sanitise_id_aa64pfr2_el1(vcpu, val);
> >  		break;
> >  	case SYS_ID_AA64ISAR1_EL1:
> >  		if (!vcpu_has_ptrauth(vcpu))
> > @@ -2027,6 +2025,23 @@ static u64 sanitise_id_aa64pfr1_el1(const
> > struct kvm_vcpu *vcpu, u64 val)
> >  	return val;
> >  }
> >  
> > +static u64 sanitise_id_aa64pfr2_el1(const struct kvm_vcpu *vcpu,
> > u64 val)
> > +{
> > +	val &= ID_AA64PFR2_EL1_FPMR |
> > +	       ID_AA64PFR2_EL1_MTEFAR |
> > +	       ID_AA64PFR2_EL1_MTESTOREONLY;
> 
> Style wise this feels inconsistent.  For these 3 registers the
> sanitise simply
> clears them if not supported, it doesn't enforce particular values
> despite
> for example MTESTOREONLY only taking values 0 and 1..
> 
> 
> > +
> > +	if (!kvm_has_mte(vcpu->kvm)) {
> > +		val &= ~ID_AA64PFR2_EL1_MTEFAR;
> > +		val &= ~ID_AA64PFR2_EL1_MTESTOREONLY;
> > +	}
> > +
> > +	if (vgic_host_has_gicv5())
> 
> ..but for this one you are forcing a specific value rather than
> clearing whatever
> was there if !vgic_host_has_gicv5()

Yeah, I think it is a combination of matching the previous behaviour
(which was to let though fields through verbatim) and what is has been
done previously for the GIC field in the ID_AA64PFR0.

I do agree that the styles are different, but I am not sure changing
that will make things clearer. It is good to be explicit about when
FEAT_GCIE is presented as IMP or not, so would prefer to leave that as
it is. The other checks would require something like:

if (val & ID_AA64PFR2_EL1_MTEFAR) {
	val &= ~ID_AA64PFR2_EL1_MTEFAR;
	val |= SYS_FIELD_PREP_ENUM(ID_AA64PFR2_EL1, MTEFAR, IMP);
}

I'm happy to do this if you feel strongly enough, but otherwise would
prefer to leave this as is for now.

Thanks,
Sascha

> 
> I don't mind that much though as still obvious what is going on and
> perhaps
> we do need to be careful this takes only a 1 or 0.
> 
> 
> > +		val |= SYS_FIELD_PREP_ENUM(ID_AA64PFR2_EL1, GCIE,
> > IMP);
> > +
> > +	return val;
> > +}
> 
> 

[PATCH v6 12/39] KVM: arm64: gic-v5: Support GICv5 FGTs & FGUs

[Sascha Bischoff]

Extend the existing FGT/FGU infrastructure to include the GICv5 trap
registers (ICH_HFGRTR_EL2, ICH_HFGWTR_EL2, ICH_HFGITR_EL2). This
involves mapping the trap registers and their bits to the
corresponding feature that introduces them (FEAT_GCIE for all, in this
case), and mapping each trap bit to the system register/instruction
controlled by it.

As of this change, none of the GICv5 instructions or register accesses
are being trapped.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
---
 arch/arm64/include/asm/kvm_host.h       | 19 +++++
 arch/arm64/include/asm/vncr_mapping.h   |  3 +
 arch/arm64/kvm/arm.c                    |  3 +
 arch/arm64/kvm/config.c                 | 97 +++++++++++++++++++++++--
 arch/arm64/kvm/emulate-nested.c         | 68 +++++++++++++++++
 arch/arm64/kvm/hyp/include/hyp/switch.h | 27 +++++++
 arch/arm64/kvm/hyp/nvhe/switch.c        |  3 +
 arch/arm64/kvm/sys_regs.c               |  2 +
 8 files changed, 215 insertions(+), 7 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 70cb9cfd760a3..64a1ee6c442f0 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -287,6 +287,9 @@ enum fgt_group_id {
 	HDFGRTR2_GROUP,
 	HDFGWTR2_GROUP = HDFGRTR2_GROUP,
 	HFGITR2_GROUP,
+	ICH_HFGRTR_GROUP,
+	ICH_HFGWTR_GROUP = ICH_HFGRTR_GROUP,
+	ICH_HFGITR_GROUP,
 
 	/* Must be last */
 	__NR_FGT_GROUP_IDS__
@@ -620,6 +623,10 @@ enum vcpu_sysreg {
 	VNCR(ICH_HCR_EL2),
 	VNCR(ICH_VMCR_EL2),
 
+	VNCR(ICH_HFGRTR_EL2),
+	VNCR(ICH_HFGWTR_EL2),
+	VNCR(ICH_HFGITR_EL2),
+
 	NR_SYS_REGS	/* Nothing after this line! */
 };
 
@@ -675,6 +682,9 @@ extern struct fgt_masks hfgwtr2_masks;
 extern struct fgt_masks hfgitr2_masks;
 extern struct fgt_masks hdfgrtr2_masks;
 extern struct fgt_masks hdfgwtr2_masks;
+extern struct fgt_masks ich_hfgrtr_masks;
+extern struct fgt_masks ich_hfgwtr_masks;
+extern struct fgt_masks ich_hfgitr_masks;
 
 extern struct fgt_masks kvm_nvhe_sym(hfgrtr_masks);
 extern struct fgt_masks kvm_nvhe_sym(hfgwtr_masks);
@@ -687,6 +697,9 @@ extern struct fgt_masks kvm_nvhe_sym(hfgwtr2_masks);
 extern struct fgt_masks kvm_nvhe_sym(hfgitr2_masks);
 extern struct fgt_masks kvm_nvhe_sym(hdfgrtr2_masks);
 extern struct fgt_masks kvm_nvhe_sym(hdfgwtr2_masks);
+extern struct fgt_masks kvm_nvhe_sym(ich_hfgrtr_masks);
+extern struct fgt_masks kvm_nvhe_sym(ich_hfgwtr_masks);
+extern struct fgt_masks kvm_nvhe_sym(ich_hfgitr_masks);
 
 struct kvm_cpu_context {
 	struct user_pt_regs regs;	/* sp = sp_el0 */
@@ -1659,6 +1672,11 @@ static __always_inline enum fgt_group_id __fgt_reg_to_group_id(enum vcpu_sysreg
 	case HDFGRTR2_EL2:
 	case HDFGWTR2_EL2:
 		return HDFGRTR2_GROUP;
+	case ICH_HFGRTR_EL2:
+	case ICH_HFGWTR_EL2:
+		return ICH_HFGRTR_GROUP;
+	case ICH_HFGITR_EL2:
+		return ICH_HFGITR_GROUP;
 	default:
 		BUILD_BUG_ON(1);
 	}
@@ -1673,6 +1691,7 @@ static __always_inline enum fgt_group_id __fgt_reg_to_group_id(enum vcpu_sysreg
 		case HDFGWTR_EL2:					\
 		case HFGWTR2_EL2:					\
 		case HDFGWTR2_EL2:					\
+		case ICH_HFGWTR_EL2:					\
 			p = &(vcpu)->arch.fgt[id].w;			\
 			break;						\
 		default:						\
diff --git a/arch/arm64/include/asm/vncr_mapping.h b/arch/arm64/include/asm/vncr_mapping.h
index c2485a862e690..14366d35ce82f 100644
--- a/arch/arm64/include/asm/vncr_mapping.h
+++ b/arch/arm64/include/asm/vncr_mapping.h
@@ -108,5 +108,8 @@
 #define VNCR_MPAMVPM5_EL2       0x968
 #define VNCR_MPAMVPM6_EL2       0x970
 #define VNCR_MPAMVPM7_EL2       0x978
+#define VNCR_ICH_HFGITR_EL2	0xB10
+#define VNCR_ICH_HFGRTR_EL2	0xB18
+#define VNCR_ICH_HFGWTR_EL2	0xB20
 
 #endif /* __ARM64_VNCR_MAPPING_H__ */
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 410ffd41fd73a..aa69fd5b372fd 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -2529,6 +2529,9 @@ static void kvm_hyp_init_symbols(void)
 	kvm_nvhe_sym(hfgitr2_masks) = hfgitr2_masks;
 	kvm_nvhe_sym(hdfgrtr2_masks)= hdfgrtr2_masks;
 	kvm_nvhe_sym(hdfgwtr2_masks)= hdfgwtr2_masks;
+	kvm_nvhe_sym(ich_hfgrtr_masks) = ich_hfgrtr_masks;
+	kvm_nvhe_sym(ich_hfgwtr_masks) = ich_hfgwtr_masks;
+	kvm_nvhe_sym(ich_hfgitr_masks) = ich_hfgitr_masks;
 
 	/*
 	 * Flush entire BSS since part of its data containing init symbols is read
diff --git a/arch/arm64/kvm/config.c b/arch/arm64/kvm/config.c
index d9f553cbf9dfd..e4ec1bda8dfcb 100644
--- a/arch/arm64/kvm/config.c
+++ b/arch/arm64/kvm/config.c
@@ -225,6 +225,7 @@ struct reg_feat_map_desc {
 #define FEAT_MTPMU		ID_AA64DFR0_EL1, MTPMU, IMP
 #define FEAT_HCX		ID_AA64MMFR1_EL1, HCX, IMP
 #define FEAT_S2PIE		ID_AA64MMFR3_EL1, S2PIE, IMP
+#define FEAT_GCIE		ID_AA64PFR2_EL1, GCIE, IMP
 
 static bool not_feat_aa64el3(struct kvm *kvm)
 {
@@ -1277,6 +1278,58 @@ static const struct reg_bits_to_feat_map vtcr_el2_feat_map[] = {
 static const DECLARE_FEAT_MAP(vtcr_el2_desc, VTCR_EL2,
 			      vtcr_el2_feat_map, FEAT_AA64EL2);
 
+static const struct reg_bits_to_feat_map ich_hfgrtr_feat_map[] = {
+	NEEDS_FEAT(ICH_HFGRTR_EL2_ICC_APR_EL1 |
+		   ICH_HFGRTR_EL2_ICC_IDRn_EL1 |
+		   ICH_HFGRTR_EL2_ICC_CR0_EL1 |
+		   ICH_HFGRTR_EL2_ICC_HPPIR_EL1 |
+		   ICH_HFGRTR_EL2_ICC_PCR_EL1 |
+		   ICH_HFGRTR_EL2_ICC_ICSR_EL1 |
+		   ICH_HFGRTR_EL2_ICC_IAFFIDR_EL1 |
+		   ICH_HFGRTR_EL2_ICC_PPI_HMRn_EL1 |
+		   ICH_HFGRTR_EL2_ICC_PPI_ENABLERn_EL1 |
+		   ICH_HFGRTR_EL2_ICC_PPI_PENDRn_EL1 |
+		   ICH_HFGRTR_EL2_ICC_PPI_PRIORITYRn_EL1 |
+		   ICH_HFGRTR_EL2_ICC_PPI_ACTIVERn_EL1,
+		   FEAT_GCIE),
+};
+
+static const DECLARE_FEAT_MAP_FGT(ich_hfgrtr_desc, ich_hfgrtr_masks,
+				  ich_hfgrtr_feat_map, FEAT_GCIE);
+
+static const struct reg_bits_to_feat_map ich_hfgwtr_feat_map[] = {
+	NEEDS_FEAT(ICH_HFGWTR_EL2_ICC_APR_EL1 |
+		   ICH_HFGWTR_EL2_ICC_CR0_EL1 |
+		   ICH_HFGWTR_EL2_ICC_PCR_EL1 |
+		   ICH_HFGWTR_EL2_ICC_ICSR_EL1 |
+		   ICH_HFGWTR_EL2_ICC_PPI_ENABLERn_EL1 |
+		   ICH_HFGWTR_EL2_ICC_PPI_PENDRn_EL1 |
+		   ICH_HFGWTR_EL2_ICC_PPI_PRIORITYRn_EL1 |
+		   ICH_HFGWTR_EL2_ICC_PPI_ACTIVERn_EL1,
+		   FEAT_GCIE),
+};
+
+static const DECLARE_FEAT_MAP_FGT(ich_hfgwtr_desc, ich_hfgwtr_masks,
+				  ich_hfgwtr_feat_map, FEAT_GCIE);
+
+static const struct reg_bits_to_feat_map ich_hfgitr_feat_map[] = {
+	NEEDS_FEAT(ICH_HFGITR_EL2_GICCDEN |
+		   ICH_HFGITR_EL2_GICCDDIS |
+		   ICH_HFGITR_EL2_GICCDPRI |
+		   ICH_HFGITR_EL2_GICCDAFF |
+		   ICH_HFGITR_EL2_GICCDPEND |
+		   ICH_HFGITR_EL2_GICCDRCFG |
+		   ICH_HFGITR_EL2_GICCDHM |
+		   ICH_HFGITR_EL2_GICCDEOI |
+		   ICH_HFGITR_EL2_GICCDDI |
+		   ICH_HFGITR_EL2_GICRCDIA |
+		   ICH_HFGITR_EL2_GICRCDNMIA,
+		   FEAT_GCIE),
+};
+
+static const DECLARE_FEAT_MAP_FGT(ich_hfgitr_desc, ich_hfgitr_masks,
+				  ich_hfgitr_feat_map, FEAT_GCIE);
+
 static void __init check_feat_map(const struct reg_bits_to_feat_map *map,
 				  int map_size, u64 resx, const char *str)
 {
@@ -1328,6 +1381,9 @@ void __init check_feature_map(void)
 	check_reg_desc(&sctlr_el2_desc);
 	check_reg_desc(&mdcr_el2_desc);
 	check_reg_desc(&vtcr_el2_desc);
+	check_reg_desc(&ich_hfgrtr_desc);
+	check_reg_desc(&ich_hfgwtr_desc);
+	check_reg_desc(&ich_hfgitr_desc);
 }
 
 static bool idreg_feat_match(struct kvm *kvm, const struct reg_bits_to_feat_map *map)
@@ -1460,6 +1516,13 @@ void compute_fgu(struct kvm *kvm, enum fgt_group_id fgt)
 		val |= compute_fgu_bits(kvm, &hdfgrtr2_desc);
 		val |= compute_fgu_bits(kvm, &hdfgwtr2_desc);
 		break;
+	case ICH_HFGRTR_GROUP:
+		val |= compute_fgu_bits(kvm, &ich_hfgrtr_desc);
+		val |= compute_fgu_bits(kvm, &ich_hfgwtr_desc);
+		break;
+	case ICH_HFGITR_GROUP:
+		val |= compute_fgu_bits(kvm, &ich_hfgitr_desc);
+		break;
 	default:
 		BUG();
 	}
@@ -1531,6 +1594,15 @@ struct resx get_reg_fixed_bits(struct kvm *kvm, enum vcpu_sysreg reg)
 	case VTCR_EL2:
 		resx = compute_reg_resx_bits(kvm, &vtcr_el2_desc, 0, 0);
 		break;
+	case ICH_HFGRTR_EL2:
+		resx = compute_reg_resx_bits(kvm, &ich_hfgrtr_desc, 0, 0);
+		break;
+	case ICH_HFGWTR_EL2:
+		resx = compute_reg_resx_bits(kvm, &ich_hfgwtr_desc, 0, 0);
+		break;
+	case ICH_HFGITR_EL2:
+		resx = compute_reg_resx_bits(kvm, &ich_hfgitr_desc, 0, 0);
+		break;
 	default:
 		WARN_ON_ONCE(1);
 		resx = (typeof(resx)){};
@@ -1565,6 +1637,12 @@ static __always_inline struct fgt_masks *__fgt_reg_to_masks(enum vcpu_sysreg reg
 		return &hdfgrtr2_masks;
 	case HDFGWTR2_EL2:
 		return &hdfgwtr2_masks;
+	case ICH_HFGRTR_EL2:
+		return &ich_hfgrtr_masks;
+	case ICH_HFGWTR_EL2:
+		return &ich_hfgwtr_masks;
+	case ICH_HFGITR_EL2:
+		return &ich_hfgitr_masks;
 	default:
 		BUILD_BUG_ON(1);
 	}
@@ -1618,12 +1696,17 @@ void kvm_vcpu_load_fgt(struct kvm_vcpu *vcpu)
 	__compute_hdfgwtr(vcpu);
 	__compute_fgt(vcpu, HAFGRTR_EL2);
 
-	if (!cpus_have_final_cap(ARM64_HAS_FGT2))
-		return;
+	if (cpus_have_final_cap(ARM64_HAS_FGT2)) {
+		__compute_fgt(vcpu, HFGRTR2_EL2);
+		__compute_fgt(vcpu, HFGWTR2_EL2);
+		__compute_fgt(vcpu, HFGITR2_EL2);
+		__compute_fgt(vcpu, HDFGRTR2_EL2);
+		__compute_fgt(vcpu, HDFGWTR2_EL2);
+	}
 
-	__compute_fgt(vcpu, HFGRTR2_EL2);
-	__compute_fgt(vcpu, HFGWTR2_EL2);
-	__compute_fgt(vcpu, HFGITR2_EL2);
-	__compute_fgt(vcpu, HDFGRTR2_EL2);
-	__compute_fgt(vcpu, HDFGWTR2_EL2);
+	if (cpus_have_final_cap(ARM64_HAS_GICV5_CPUIF)) {
+		__compute_fgt(vcpu, ICH_HFGRTR_EL2);
+		__compute_fgt(vcpu, ICH_HFGWTR_EL2);
+		__compute_fgt(vcpu, ICH_HFGITR_EL2);
+	}
 }
diff --git a/arch/arm64/kvm/emulate-nested.c b/arch/arm64/kvm/emulate-nested.c
index 22d497554c949..dba7ced74ca5e 100644
--- a/arch/arm64/kvm/emulate-nested.c
+++ b/arch/arm64/kvm/emulate-nested.c
@@ -2053,6 +2053,60 @@ static const struct encoding_to_trap_config encoding_to_fgt[] __initconst = {
 	SR_FGT(SYS_AMEVCNTR0_EL0(2),	HAFGRTR, AMEVCNTR02_EL0, 1),
 	SR_FGT(SYS_AMEVCNTR0_EL0(1),	HAFGRTR, AMEVCNTR01_EL0, 1),
 	SR_FGT(SYS_AMEVCNTR0_EL0(0),	HAFGRTR, AMEVCNTR00_EL0, 1),
+
+	/*
+	 * ICH_HFGRTR_EL2 & ICH_HFGWTR_EL2
+	 */
+	SR_FGT(SYS_ICC_APR_EL1,			ICH_HFGRTR, ICC_APR_EL1, 0),
+	SR_FGT(SYS_ICC_IDR0_EL1,		ICH_HFGRTR, ICC_IDRn_EL1, 0),
+	SR_FGT(SYS_ICC_CR0_EL1,			ICH_HFGRTR, ICC_CR0_EL1, 0),
+	SR_FGT(SYS_ICC_HPPIR_EL1,		ICH_HFGRTR, ICC_HPPIR_EL1, 0),
+	SR_FGT(SYS_ICC_PCR_EL1,			ICH_HFGRTR, ICC_PCR_EL1, 0),
+	SR_FGT(SYS_ICC_ICSR_EL1,		ICH_HFGRTR, ICC_ICSR_EL1, 0),
+	SR_FGT(SYS_ICC_IAFFIDR_EL1,		ICH_HFGRTR, ICC_IAFFIDR_EL1, 0),
+	SR_FGT(SYS_ICC_PPI_HMR0_EL1,		ICH_HFGRTR, ICC_PPI_HMRn_EL1, 0),
+	SR_FGT(SYS_ICC_PPI_HMR1_EL1,		ICH_HFGRTR, ICC_PPI_HMRn_EL1, 0),
+	SR_FGT(SYS_ICC_PPI_ENABLER0_EL1,	ICH_HFGRTR, ICC_PPI_ENABLERn_EL1, 0),
+	SR_FGT(SYS_ICC_PPI_ENABLER1_EL1,	ICH_HFGRTR, ICC_PPI_ENABLERn_EL1, 0),
+	SR_FGT(SYS_ICC_PPI_CPENDR0_EL1,		ICH_HFGRTR, ICC_PPI_PENDRn_EL1, 0),
+	SR_FGT(SYS_ICC_PPI_CPENDR1_EL1,		ICH_HFGRTR, ICC_PPI_PENDRn_EL1, 0),
+	SR_FGT(SYS_ICC_PPI_SPENDR0_EL1,		ICH_HFGRTR, ICC_PPI_PENDRn_EL1, 0),
+	SR_FGT(SYS_ICC_PPI_SPENDR1_EL1,		ICH_HFGRTR, ICC_PPI_PENDRn_EL1, 0),
+	SR_FGT(SYS_ICC_PPI_PRIORITYR0_EL1,	ICH_HFGRTR, ICC_PPI_PRIORITYRn_EL1, 0),
+	SR_FGT(SYS_ICC_PPI_PRIORITYR1_EL1,	ICH_HFGRTR, ICC_PPI_PRIORITYRn_EL1, 0),
+	SR_FGT(SYS_ICC_PPI_PRIORITYR2_EL1,	ICH_HFGRTR, ICC_PPI_PRIORITYRn_EL1, 0),
+	SR_FGT(SYS_ICC_PPI_PRIORITYR3_EL1,	ICH_HFGRTR, ICC_PPI_PRIORITYRn_EL1, 0),
+	SR_FGT(SYS_ICC_PPI_PRIORITYR4_EL1,	ICH_HFGRTR, ICC_PPI_PRIORITYRn_EL1, 0),
+	SR_FGT(SYS_ICC_PPI_PRIORITYR5_EL1,	ICH_HFGRTR, ICC_PPI_PRIORITYRn_EL1, 0),
+	SR_FGT(SYS_ICC_PPI_PRIORITYR6_EL1,	ICH_HFGRTR, ICC_PPI_PRIORITYRn_EL1, 0),
+	SR_FGT(SYS_ICC_PPI_PRIORITYR7_EL1,	ICH_HFGRTR, ICC_PPI_PRIORITYRn_EL1, 0),
+	SR_FGT(SYS_ICC_PPI_PRIORITYR8_EL1,	ICH_HFGRTR, ICC_PPI_PRIORITYRn_EL1, 0),
+	SR_FGT(SYS_ICC_PPI_PRIORITYR9_EL1,	ICH_HFGRTR, ICC_PPI_PRIORITYRn_EL1, 0),
+	SR_FGT(SYS_ICC_PPI_PRIORITYR10_EL1,	ICH_HFGRTR, ICC_PPI_PRIORITYRn_EL1, 0),
+	SR_FGT(SYS_ICC_PPI_PRIORITYR11_EL1,	ICH_HFGRTR, ICC_PPI_PRIORITYRn_EL1, 0),
+	SR_FGT(SYS_ICC_PPI_PRIORITYR12_EL1,	ICH_HFGRTR, ICC_PPI_PRIORITYRn_EL1, 0),
+	SR_FGT(SYS_ICC_PPI_PRIORITYR13_EL1,	ICH_HFGRTR, ICC_PPI_PRIORITYRn_EL1, 0),
+	SR_FGT(SYS_ICC_PPI_PRIORITYR14_EL1,	ICH_HFGRTR, ICC_PPI_PRIORITYRn_EL1, 0),
+	SR_FGT(SYS_ICC_PPI_PRIORITYR15_EL1,	ICH_HFGRTR, ICC_PPI_PRIORITYRn_EL1, 0),
+	SR_FGT(SYS_ICC_PPI_CACTIVER0_EL1,	ICH_HFGRTR, ICC_PPI_ACTIVERn_EL1, 0),
+	SR_FGT(SYS_ICC_PPI_CACTIVER1_EL1,	ICH_HFGRTR, ICC_PPI_ACTIVERn_EL1, 0),
+	SR_FGT(SYS_ICC_PPI_SACTIVER0_EL1,	ICH_HFGRTR, ICC_PPI_ACTIVERn_EL1, 0),
+	SR_FGT(SYS_ICC_PPI_SACTIVER1_EL1,	ICH_HFGRTR, ICC_PPI_ACTIVERn_EL1, 0),
+
+	/*
+	 * ICH_HFGITR_EL2
+	 */
+	SR_FGT(GICV5_OP_GIC_CDEN,	ICH_HFGITR, GICCDEN, 0),
+	SR_FGT(GICV5_OP_GIC_CDDIS,	ICH_HFGITR, GICCDDIS, 0),
+	SR_FGT(GICV5_OP_GIC_CDPRI,	ICH_HFGITR, GICCDPRI, 0),
+	SR_FGT(GICV5_OP_GIC_CDAFF,	ICH_HFGITR, GICCDAFF, 0),
+	SR_FGT(GICV5_OP_GIC_CDPEND,	ICH_HFGITR, GICCDPEND, 0),
+	SR_FGT(GICV5_OP_GIC_CDRCFG,	ICH_HFGITR, GICCDRCFG, 0),
+	SR_FGT(GICV5_OP_GIC_CDHM,	ICH_HFGITR, GICCDHM, 0),
+	SR_FGT(GICV5_OP_GIC_CDEOI,	ICH_HFGITR, GICCDEOI, 0),
+	SR_FGT(GICV5_OP_GIC_CDDI,	ICH_HFGITR, GICCDDI, 0),
+	SR_FGT(GICV5_OP_GICR_CDIA,	ICH_HFGITR, GICRCDIA, 0),
+	SR_FGT(GICV5_OP_GICR_CDNMIA,	ICH_HFGITR, GICRCDNMIA, 0),
 };
 
 /*
@@ -2127,6 +2181,9 @@ FGT_MASKS(hfgwtr2_masks, HFGWTR2_EL2);
 FGT_MASKS(hfgitr2_masks, HFGITR2_EL2);
 FGT_MASKS(hdfgrtr2_masks, HDFGRTR2_EL2);
 FGT_MASKS(hdfgwtr2_masks, HDFGWTR2_EL2);
+FGT_MASKS(ich_hfgrtr_masks, ICH_HFGRTR_EL2);
+FGT_MASKS(ich_hfgwtr_masks, ICH_HFGWTR_EL2);
+FGT_MASKS(ich_hfgitr_masks, ICH_HFGITR_EL2);
 
 static __init bool aggregate_fgt(union trap_config tc)
 {
@@ -2162,6 +2219,14 @@ static __init bool aggregate_fgt(union trap_config tc)
 		rmasks = &hfgitr2_masks;
 		wmasks = NULL;
 		break;
+	case ICH_HFGRTR_GROUP:
+		rmasks = &ich_hfgrtr_masks;
+		wmasks = &ich_hfgwtr_masks;
+		break;
+	case ICH_HFGITR_GROUP:
+		rmasks = &ich_hfgitr_masks;
+		wmasks = NULL;
+		break;
 	}
 
 	rresx = rmasks->res0 | rmasks->res1;
@@ -2232,6 +2297,9 @@ static __init int check_all_fgt_masks(int ret)
 		&hfgitr2_masks,
 		&hdfgrtr2_masks,
 		&hdfgwtr2_masks,
+		&ich_hfgrtr_masks,
+		&ich_hfgwtr_masks,
+		&ich_hfgitr_masks,
 	};
 	int err = 0;
 
diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h
index 2597e8bda8672..ae04fd680d1e2 100644
--- a/arch/arm64/kvm/hyp/include/hyp/switch.h
+++ b/arch/arm64/kvm/hyp/include/hyp/switch.h
@@ -233,6 +233,18 @@ static inline void __activate_traps_hfgxtr(struct kvm_vcpu *vcpu)
 	__activate_fgt(hctxt, vcpu, HDFGWTR2_EL2);
 }
 
+static inline void __activate_traps_ich_hfgxtr(struct kvm_vcpu *vcpu)
+{
+	struct kvm_cpu_context *hctxt = host_data_ptr(host_ctxt);
+
+	if (!cpus_have_final_cap(ARM64_HAS_GICV5_CPUIF))
+		return;
+
+	__activate_fgt(hctxt, vcpu, ICH_HFGRTR_EL2);
+	__activate_fgt(hctxt, vcpu, ICH_HFGWTR_EL2);
+	__activate_fgt(hctxt, vcpu, ICH_HFGITR_EL2);
+}
+
 #define __deactivate_fgt(htcxt, vcpu, reg)				\
 	do {								\
 		write_sysreg_s(ctxt_sys_reg(hctxt, reg),		\
@@ -265,6 +277,19 @@ static inline void __deactivate_traps_hfgxtr(struct kvm_vcpu *vcpu)
 	__deactivate_fgt(hctxt, vcpu, HDFGWTR2_EL2);
 }
 
+static inline void __deactivate_traps_ich_hfgxtr(struct kvm_vcpu *vcpu)
+{
+	struct kvm_cpu_context *hctxt = host_data_ptr(host_ctxt);
+
+	if (!cpus_have_final_cap(ARM64_HAS_GICV5_CPUIF))
+		return;
+
+	__deactivate_fgt(hctxt, vcpu, ICH_HFGRTR_EL2);
+	__deactivate_fgt(hctxt, vcpu, ICH_HFGWTR_EL2);
+	__deactivate_fgt(hctxt, vcpu, ICH_HFGITR_EL2);
+
+}
+
 static inline void  __activate_traps_mpam(struct kvm_vcpu *vcpu)
 {
 	u64 r = MPAM2_EL2_TRAPMPAM0EL1 | MPAM2_EL2_TRAPMPAM1EL1;
@@ -328,6 +353,7 @@ static inline void __activate_traps_common(struct kvm_vcpu *vcpu)
 	}
 
 	__activate_traps_hfgxtr(vcpu);
+	__activate_traps_ich_hfgxtr(vcpu);
 	__activate_traps_mpam(vcpu);
 }
 
@@ -345,6 +371,7 @@ static inline void __deactivate_traps_common(struct kvm_vcpu *vcpu)
 		write_sysreg_s(ctxt_sys_reg(hctxt, HCRX_EL2), SYS_HCRX_EL2);
 
 	__deactivate_traps_hfgxtr(vcpu);
+	__deactivate_traps_ich_hfgxtr(vcpu);
 	__deactivate_traps_mpam();
 }
 
diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c
index 779089e42681e..b41485ce295ab 100644
--- a/arch/arm64/kvm/hyp/nvhe/switch.c
+++ b/arch/arm64/kvm/hyp/nvhe/switch.c
@@ -44,6 +44,9 @@ struct fgt_masks hfgwtr2_masks;
 struct fgt_masks hfgitr2_masks;
 struct fgt_masks hdfgrtr2_masks;
 struct fgt_masks hdfgwtr2_masks;
+struct fgt_masks ich_hfgrtr_masks;
+struct fgt_masks ich_hfgwtr_masks;
+struct fgt_masks ich_hfgitr_masks;
 
 extern void kvm_nvhe_prepare_backtrace(unsigned long fp, unsigned long pc);
 
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 140cf35f4eeb4..cd6deaf473159 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -5661,6 +5661,8 @@ void kvm_calculate_traps(struct kvm_vcpu *vcpu)
 	compute_fgu(kvm, HFGRTR2_GROUP);
 	compute_fgu(kvm, HFGITR2_GROUP);
 	compute_fgu(kvm, HDFGRTR2_GROUP);
+	compute_fgu(kvm, ICH_HFGRTR_GROUP);
+	compute_fgu(kvm, ICH_HFGITR_GROUP);
 
 	set_bit(KVM_ARCH_FLAG_FGU_INITIALIZED, &kvm->arch.flags);
 out:
-- 
2.34.1

[PATCH v6 13/39] KVM: arm64: gic-v5: Add emulation for ICC_IAFFIDR_EL1 accesses

[Sascha Bischoff]

GICv5 doesn't provide an ICV_IAFFIDR_EL1 or ICH_IAFFIDR_EL2 for
providing the IAFFID to the guest. A guest access to the
ICC_IAFFIDR_EL1 must therefore be trapped and emulated to avoid the
guest accessing the host's ICC_IAFFIDR_EL1.

The virtual IAFFID is provided to the guest when it reads
ICC_IAFFIDR_EL1 (which always traps back to the hypervisor). Writes are
rightly ignored. KVM treats the GICv5 VPEID, the virtual IAFFID, and
the vcpu_id as the same, and so the vcpu_id is returned.

The trapping for the ICC_IAFFIDR_EL1 is always enabled when in a guest
context.

Co-authored-by: Timothy Hayes <timothy.hayes@arm.com>
Signed-off-by: Timothy Hayes <timothy.hayes@arm.com>
Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
---
 arch/arm64/kvm/config.c    | 10 +++++++++-
 arch/arm64/kvm/sys_regs.c  | 16 ++++++++++++++++
 arch/arm64/kvm/vgic/vgic.h |  5 +++++
 3 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/config.c b/arch/arm64/kvm/config.c
index e4ec1bda8dfcb..bac5f49fdbdef 100644
--- a/arch/arm64/kvm/config.c
+++ b/arch/arm64/kvm/config.c
@@ -1684,6 +1684,14 @@ static void __compute_hdfgwtr(struct kvm_vcpu *vcpu)
 		*vcpu_fgt(vcpu, HDFGWTR_EL2) |= HDFGWTR_EL2_MDSCR_EL1;
 }
 
+static void __compute_ich_hfgrtr(struct kvm_vcpu *vcpu)
+{
+	__compute_fgt(vcpu, ICH_HFGRTR_EL2);
+
+	/* ICC_IAFFIDR_EL1 *always* needs to be trapped when running a guest */
+	*vcpu_fgt(vcpu, ICH_HFGRTR_EL2) &= ~ICH_HFGRTR_EL2_ICC_IAFFIDR_EL1;
+}
+
 void kvm_vcpu_load_fgt(struct kvm_vcpu *vcpu)
 {
 	if (!cpus_have_final_cap(ARM64_HAS_FGT))
@@ -1705,7 +1713,7 @@ void kvm_vcpu_load_fgt(struct kvm_vcpu *vcpu)
 	}
 
 	if (cpus_have_final_cap(ARM64_HAS_GICV5_CPUIF)) {
-		__compute_fgt(vcpu, ICH_HFGRTR_EL2);
+		__compute_ich_hfgrtr(vcpu);
 		__compute_fgt(vcpu, ICH_HFGWTR_EL2);
 		__compute_fgt(vcpu, ICH_HFGITR_EL2);
 	}
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index cd6deaf473159..d4531457ea026 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -681,6 +681,21 @@ static bool access_gic_dir(struct kvm_vcpu *vcpu,
 	return true;
 }
 
+static bool access_gicv5_iaffid(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
+				const struct sys_reg_desc *r)
+{
+	if (p->is_write)
+		return undef_access(vcpu, p, r);
+
+	/*
+	 * For GICv5 VMs, the IAFFID value is the same as the VPE ID. The VPE ID
+	 * is the same as the VCPU's ID.
+	 */
+	p->regval = FIELD_PREP(ICC_IAFFIDR_EL1_IAFFID, vcpu->vcpu_id);
+
+	return true;
+}
+
 static bool trap_raz_wi(struct kvm_vcpu *vcpu,
 			struct sys_reg_params *p,
 			const struct sys_reg_desc *r)
@@ -3405,6 +3420,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
 	{ SYS_DESC(SYS_ICC_AP1R1_EL1), undef_access },
 	{ SYS_DESC(SYS_ICC_AP1R2_EL1), undef_access },
 	{ SYS_DESC(SYS_ICC_AP1R3_EL1), undef_access },
+	{ SYS_DESC(SYS_ICC_IAFFIDR_EL1), access_gicv5_iaffid },
 	{ SYS_DESC(SYS_ICC_DIR_EL1), access_gic_dir },
 	{ SYS_DESC(SYS_ICC_RPR_EL1), undef_access },
 	{ SYS_DESC(SYS_ICC_SGI1R_EL1), access_gic_sgi },
diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h
index f2924f8211974..7b7eed69d7973 100644
--- a/arch/arm64/kvm/vgic/vgic.h
+++ b/arch/arm64/kvm/vgic/vgic.h
@@ -447,6 +447,11 @@ static inline bool kvm_has_gicv3(struct kvm *kvm)
 	return kvm_has_feat(kvm, ID_AA64PFR0_EL1, GIC, IMP);
 }
 
+static inline bool kvm_has_gicv5(struct kvm *kvm)
+{
+	return kvm_has_feat(kvm, ID_AA64PFR2_EL1, GCIE, IMP);
+}
+
 void vgic_v3_flush_nested(struct kvm_vcpu *vcpu);
 void vgic_v3_sync_nested(struct kvm_vcpu *vcpu);
 void vgic_v3_load_nested(struct kvm_vcpu *vcpu);
-- 
2.34.1

Re: [PATCH v6 13/39] KVM: arm64: gic-v5: Add emulation for ICC_IAFFIDR_EL1 accesses

[Jonathan Cameron]

On Tue, 17 Mar 2026 11:43:18 +0000
Sascha Bischoff <Sascha.Bischoff@arm.com> wrote:

> GICv5 doesn't provide an ICV_IAFFIDR_EL1 or ICH_IAFFIDR_EL2 for
> providing the IAFFID to the guest. A guest access to the
> ICC_IAFFIDR_EL1 must therefore be trapped and emulated to avoid the
> guest accessing the host's ICC_IAFFIDR_EL1.
> 
> The virtual IAFFID is provided to the guest when it reads
> ICC_IAFFIDR_EL1 (which always traps back to the hypervisor). Writes are
> rightly ignored. KVM treats the GICv5 VPEID, the virtual IAFFID, and
> the vcpu_id as the same, and so the vcpu_id is returned.
> 
> The trapping for the ICC_IAFFIDR_EL1 is always enabled when in a guest
> context.
> 
> Co-authored-by: Timothy Hayes <timothy.hayes@arm.com>
> Signed-off-by: Timothy Hayes <timothy.hayes@arm.com>
> Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>

[PATCH v6 14/39] KVM: arm64: gic-v5: Trap and emulate ICC_IDR0_EL1 accesses

[Sascha Bischoff]

Unless accesses to the ICC_IDR0_EL1 are trapped by KVM, the guest
reads the same state as the host. This isn't desirable as it limits
the migratability of VMs and means that KVM can't hide hardware
features such as FEAT_GCIE_LEGACY.

Trap and emulate accesses to the register, and present KVM's chosen ID
bits and Priority bits (which is 5, as GICv5 only supports 5 bits of
priority in the CPU interface). FEAT_GCIE_LEGACY is never presented to
the guest as it is only relevant for nested guests doing mixed GICv5
and GICv3 support.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
---
 arch/arm64/kvm/config.c   | 11 +++++++++--
 arch/arm64/kvm/sys_regs.c | 23 +++++++++++++++++++++++
 2 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kvm/config.c b/arch/arm64/kvm/config.c
index bac5f49fdbdef..5663f25905e83 100644
--- a/arch/arm64/kvm/config.c
+++ b/arch/arm64/kvm/config.c
@@ -1688,8 +1688,15 @@ static void __compute_ich_hfgrtr(struct kvm_vcpu *vcpu)
 {
 	__compute_fgt(vcpu, ICH_HFGRTR_EL2);
 
-	/* ICC_IAFFIDR_EL1 *always* needs to be trapped when running a guest */
-	*vcpu_fgt(vcpu, ICH_HFGRTR_EL2) &= ~ICH_HFGRTR_EL2_ICC_IAFFIDR_EL1;
+	/*
+	 * ICC_IAFFIDR_EL1 *always* needs to be trapped when running a guest.
+	 *
+	 * We also trap accesses to ICC_IDR0_EL1 to allow us to completely hide
+	 * FEAT_GCIE_LEGACY from the guest, and to (potentially) present fewer
+	 * ID bits than the host supports.
+	 */
+	*vcpu_fgt(vcpu, ICH_HFGRTR_EL2) &= ~(ICH_HFGRTR_EL2_ICC_IAFFIDR_EL1 |
+					     ICH_HFGRTR_EL2_ICC_IDRn_EL1);
 }
 
 void kvm_vcpu_load_fgt(struct kvm_vcpu *vcpu)
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index d4531457ea026..85300e76bbe46 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -681,6 +681,28 @@ static bool access_gic_dir(struct kvm_vcpu *vcpu,
 	return true;
 }
 
+static bool access_gicv5_idr0(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
+			      const struct sys_reg_desc *r)
+{
+	if (p->is_write)
+		return undef_access(vcpu, p, r);
+
+	/*
+	 * Expose KVM's priority- and ID-bits to the guest, but not GCIE_LEGACY.
+	 *
+	 * Note: for GICv5 the mimic the way that the num_pri_bits and
+	 * num_id_bits fields are used with GICv3:
+	 * - num_pri_bits stores the actual number of priority bits, whereas the
+	 *   register field stores num_pri_bits - 1.
+	 * - num_id_bits stores the raw field value, which is 0b0000 for 16 bits
+	 *   and 0b0001 for 24 bits.
+	 */
+	p->regval = FIELD_PREP(ICC_IDR0_EL1_PRI_BITS, vcpu->arch.vgic_cpu.num_pri_bits - 1) |
+		    FIELD_PREP(ICC_IDR0_EL1_ID_BITS, vcpu->arch.vgic_cpu.num_id_bits);
+
+	return true;
+}
+
 static bool access_gicv5_iaffid(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
 				const struct sys_reg_desc *r)
 {
@@ -3420,6 +3442,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
 	{ SYS_DESC(SYS_ICC_AP1R1_EL1), undef_access },
 	{ SYS_DESC(SYS_ICC_AP1R2_EL1), undef_access },
 	{ SYS_DESC(SYS_ICC_AP1R3_EL1), undef_access },
+	{ SYS_DESC(SYS_ICC_IDR0_EL1), access_gicv5_idr0 },
 	{ SYS_DESC(SYS_ICC_IAFFIDR_EL1), access_gicv5_iaffid },
 	{ SYS_DESC(SYS_ICC_DIR_EL1), access_gic_dir },
 	{ SYS_DESC(SYS_ICC_RPR_EL1), undef_access },
-- 
2.34.1

Re: [PATCH v6 14/39] KVM: arm64: gic-v5: Trap and emulate ICC_IDR0_EL1 accesses

[Jonathan Cameron]

On Tue, 17 Mar 2026 11:43:34 +0000
Sascha Bischoff <Sascha.Bischoff@arm.com> wrote:

> Unless accesses to the ICC_IDR0_EL1 are trapped by KVM, the guest
> reads the same state as the host. This isn't desirable as it limits
> the migratability of VMs and means that KVM can't hide hardware
> features such as FEAT_GCIE_LEGACY.
> 
> Trap and emulate accesses to the register, and present KVM's chosen ID
> bits and Priority bits (which is 5, as GICv5 only supports 5 bits of
> priority in the CPU interface). FEAT_GCIE_LEGACY is never presented to
> the guest as it is only relevant for nested guests doing mixed GICv5
> and GICv3 support.
> 
> Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Does what I'd expect.

Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>

[PATCH v6 15/39] KVM: arm64: gic-v5: Add vgic-v5 save/restore hyp interface

[Sascha Bischoff]

Introduce the following hyp functions to save/restore GICv5 state:

* __vgic_v5_save_apr()
* __vgic_v5_restore_vmcr_apr()
* __vgic_v5_save_ppi_state()	- no hypercall required
* __vgic_v5_restore_ppi_state()	- no hypercall required
* __vgic_v5_save_state()	- no hypercall required
* __vgic_v5_restore_state()	- no hypercall required

Note that the functions tagged as not requiring hypercalls are always
called directly from the same context. They are either called via the
vgic_save_state()/vgic_restore_state() path when running with VHE, or
via __hyp_vgic_save_state()/__hyp_vgic_restore_state() otherwise. This
mimics how vgic_v3_save_state()/vgic_v3_restore_state() are
implemented.

Overall, the state of the following registers is saved/restored:

* ICC_ICSR_EL1
* ICH_APR_EL2
* ICH_PPI_ACTIVERx_EL2
* ICH_PPI_DVIRx_EL2
* ICH_PPI_ENABLERx_EL2
* ICH_PPI_PENDRx_EL2
* ICH_PPI_PRIORITYRx_EL2
* ICH_VMCR_EL2

All of these are saved/restored to/from the KVM vgic_v5 CPUIF shadow
state, with the exception of the PPI active, pending, and enable
state. The pending state is saved and restored from kvm_host_data as
any changes here need to be tracked and propagated back to the
vgic_irq shadow structures (coming in a future commit). Therefore, an
entry and an exit copy is required. The active and enable state is
restored from the vgic_v5 CPUIF, but is saved to kvm_host_data. Again,
this needs to by synced back into the shadow data structures.

The ICSR must be save/restored as this register is shared between host
and guest. Therefore, to avoid leaking host state to the guest, this
must be saved and restored. Moreover, as this can by used by the host
at any time, it must be save/restored eagerly. Note: the host state is
not preserved as the host should only use this register when
preemption is disabled.

As with GICv3, the VMCR is eagerly saved as this is required when
checking if interrupts can be injected or not, and therefore impacts
things such as WFI.

As part of restoring the ICH_VMCR_EL2 and ICH_APR_EL2, GICv3-compat
mode is also disabled by setting the ICH_VCTLR_EL2.V3 bit to 0. The
correspoinding GICv3-compat mode enable is part of the VMCR & APR
restore for a GICv3 guest as it only takes effect when actually
running a guest.

Co-authored-by: Timothy Hayes <timothy.hayes@arm.com>
Signed-off-by: Timothy Hayes <timothy.hayes@arm.com>
Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
---
 arch/arm64/include/asm/kvm_asm.h   |   2 +
 arch/arm64/include/asm/kvm_host.h  |  16 +++
 arch/arm64/include/asm/kvm_hyp.h   |   9 ++
 arch/arm64/kvm/hyp/nvhe/Makefile   |   2 +-
 arch/arm64/kvm/hyp/nvhe/hyp-main.c |  16 +++
 arch/arm64/kvm/hyp/vgic-v5-sr.c    | 170 +++++++++++++++++++++++++++++
 arch/arm64/kvm/hyp/vhe/Makefile    |   2 +-
 include/kvm/arm_vgic.h             |  22 ++++
 8 files changed, 237 insertions(+), 2 deletions(-)
 create mode 100644 arch/arm64/kvm/hyp/vgic-v5-sr.c

diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index a1ad12c72ebf1..44e4696ca113e 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -89,6 +89,8 @@ enum __kvm_host_smccc_func {
 	__KVM_HOST_SMCCC_FUNC___pkvm_vcpu_load,
 	__KVM_HOST_SMCCC_FUNC___pkvm_vcpu_put,
 	__KVM_HOST_SMCCC_FUNC___pkvm_tlb_flush_vmid,
+	__KVM_HOST_SMCCC_FUNC___vgic_v5_save_apr,
+	__KVM_HOST_SMCCC_FUNC___vgic_v5_restore_vmcr_apr,
 };
 
 #define DECLARE_KVM_VHE_SYM(sym)	extern char sym[]
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 64a1ee6c442f0..c4a172b702063 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -800,6 +800,22 @@ struct kvm_host_data {
 
 	/* Last vgic_irq part of the AP list recorded in an LR */
 	struct vgic_irq *last_lr_irq;
+
+	/* PPI state tracking for GICv5-based guests */
+	struct {
+		/*
+		 * For tracking the PPI pending state, we need both the entry
+		 * state and exit state to correctly detect edges as it is
+		 * possible that an interrupt has been injected in software in
+		 * the interim.
+		 */
+		DECLARE_BITMAP(pendr_entry, VGIC_V5_NR_PRIVATE_IRQS);
+		DECLARE_BITMAP(pendr_exit, VGIC_V5_NR_PRIVATE_IRQS);
+
+		/* The saved state of the regs when leaving the guest */
+		DECLARE_BITMAP(activer_exit, VGIC_V5_NR_PRIVATE_IRQS);
+		DECLARE_BITMAP(enabler_exit, VGIC_V5_NR_PRIVATE_IRQS);
+	} vgic_v5_ppi_state;
 };
 
 struct kvm_host_psci_config {
diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h
index 76ce2b94bd97e..2d8dfd534bd9d 100644
--- a/arch/arm64/include/asm/kvm_hyp.h
+++ b/arch/arm64/include/asm/kvm_hyp.h
@@ -87,6 +87,15 @@ void __vgic_v3_save_aprs(struct vgic_v3_cpu_if *cpu_if);
 void __vgic_v3_restore_vmcr_aprs(struct vgic_v3_cpu_if *cpu_if);
 int __vgic_v3_perform_cpuif_access(struct kvm_vcpu *vcpu);
 
+/* GICv5 */
+void __vgic_v5_save_apr(struct vgic_v5_cpu_if *cpu_if);
+void __vgic_v5_restore_vmcr_apr(struct vgic_v5_cpu_if *cpu_if);
+/* No hypercalls for the following */
+void __vgic_v5_save_ppi_state(struct vgic_v5_cpu_if *cpu_if);
+void __vgic_v5_restore_ppi_state(struct vgic_v5_cpu_if *cpu_if);
+void __vgic_v5_save_state(struct vgic_v5_cpu_if *cpu_if);
+void __vgic_v5_restore_state(struct vgic_v5_cpu_if *cpu_if);
+
 #ifdef __KVM_NVHE_HYPERVISOR__
 void __timer_enable_traps(struct kvm_vcpu *vcpu);
 void __timer_disable_traps(struct kvm_vcpu *vcpu);
diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile
index a244ec25f8c5b..84a3bf96def6b 100644
--- a/arch/arm64/kvm/hyp/nvhe/Makefile
+++ b/arch/arm64/kvm/hyp/nvhe/Makefile
@@ -26,7 +26,7 @@ hyp-obj-y := timer-sr.o sysreg-sr.o debug-sr.o switch.o tlb.o hyp-init.o host.o
 	 hyp-main.o hyp-smp.o psci-relay.o early_alloc.o page_alloc.o \
 	 cache.o setup.o mm.o mem_protect.o sys_regs.o pkvm.o stacktrace.o ffa.o
 hyp-obj-y += ../vgic-v3-sr.o ../aarch32.o ../vgic-v2-cpuif-proxy.o ../entry.o \
-	 ../fpsimd.o ../hyp-entry.o ../exception.o ../pgtable.o
+	 ../fpsimd.o ../hyp-entry.o ../exception.o ../pgtable.o ../vgic-v5-sr.o
 hyp-obj-y += ../../../kernel/smccc-call.o
 hyp-obj-$(CONFIG_LIST_HARDENED) += list_debug.o
 hyp-obj-y += $(lib-objs)
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
index e7790097db93a..007fc993f2319 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
@@ -589,6 +589,20 @@ static void handle___pkvm_teardown_vm(struct kvm_cpu_context *host_ctxt)
 	cpu_reg(host_ctxt, 1) = __pkvm_teardown_vm(handle);
 }
 
+static void handle___vgic_v5_save_apr(struct kvm_cpu_context *host_ctxt)
+{
+	DECLARE_REG(struct vgic_v5_cpu_if *, cpu_if, host_ctxt, 1);
+
+	__vgic_v5_save_apr(kern_hyp_va(cpu_if));
+}
+
+static void handle___vgic_v5_restore_vmcr_apr(struct kvm_cpu_context *host_ctxt)
+{
+	DECLARE_REG(struct vgic_v5_cpu_if *, cpu_if, host_ctxt, 1);
+
+	__vgic_v5_restore_vmcr_apr(kern_hyp_va(cpu_if));
+}
+
 typedef void (*hcall_t)(struct kvm_cpu_context *);
 
 #define HANDLE_FUNC(x)	[__KVM_HOST_SMCCC_FUNC_##x] = (hcall_t)handle_##x
@@ -630,6 +644,8 @@ static const hcall_t host_hcall[] = {
 	HANDLE_FUNC(__pkvm_vcpu_load),
 	HANDLE_FUNC(__pkvm_vcpu_put),
 	HANDLE_FUNC(__pkvm_tlb_flush_vmid),
+	HANDLE_FUNC(__vgic_v5_save_apr),
+	HANDLE_FUNC(__vgic_v5_restore_vmcr_apr),
 };
 
 static void handle_host_hcall(struct kvm_cpu_context *host_ctxt)
diff --git a/arch/arm64/kvm/hyp/vgic-v5-sr.c b/arch/arm64/kvm/hyp/vgic-v5-sr.c
new file mode 100644
index 0000000000000..f34ea219cc4e9
--- /dev/null
+++ b/arch/arm64/kvm/hyp/vgic-v5-sr.c
@@ -0,0 +1,170 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2025, 2026 - Arm Ltd
+ */
+
+#include <linux/irqchip/arm-gic-v5.h>
+
+#include <asm/kvm_hyp.h>
+
+void __vgic_v5_save_apr(struct vgic_v5_cpu_if *cpu_if)
+{
+	cpu_if->vgic_apr = read_sysreg_s(SYS_ICH_APR_EL2);
+}
+
+static void  __vgic_v5_compat_mode_disable(void)
+{
+	sysreg_clear_set_s(SYS_ICH_VCTLR_EL2, ICH_VCTLR_EL2_V3, 0);
+	isb();
+}
+
+void __vgic_v5_restore_vmcr_apr(struct vgic_v5_cpu_if *cpu_if)
+{
+	__vgic_v5_compat_mode_disable();
+
+	write_sysreg_s(cpu_if->vgic_vmcr, SYS_ICH_VMCR_EL2);
+	write_sysreg_s(cpu_if->vgic_apr, SYS_ICH_APR_EL2);
+}
+
+void __vgic_v5_save_ppi_state(struct vgic_v5_cpu_if *cpu_if)
+{
+	/*
+	 * The following code assumes that the bitmap storage that we have for
+	 * PPIs is either 64 (architected PPIs, only) or 128 bits (architected &
+	 * impdef PPIs).
+	 */
+	BUILD_BUG_ON(VGIC_V5_NR_PRIVATE_IRQS % 64);
+
+	bitmap_write(host_data_ptr(vgic_v5_ppi_state)->activer_exit,
+		     read_sysreg_s(SYS_ICH_PPI_ACTIVER0_EL2), 0, 64);
+	bitmap_write(host_data_ptr(vgic_v5_ppi_state)->enabler_exit,
+		     read_sysreg_s(SYS_ICH_PPI_ENABLER0_EL2), 0, 64);
+	bitmap_write(host_data_ptr(vgic_v5_ppi_state)->pendr_exit,
+		     read_sysreg_s(SYS_ICH_PPI_PENDR0_EL2), 0, 64);
+
+	cpu_if->vgic_ppi_priorityr[0] = read_sysreg_s(SYS_ICH_PPI_PRIORITYR0_EL2);
+	cpu_if->vgic_ppi_priorityr[1] = read_sysreg_s(SYS_ICH_PPI_PRIORITYR1_EL2);
+	cpu_if->vgic_ppi_priorityr[2] = read_sysreg_s(SYS_ICH_PPI_PRIORITYR2_EL2);
+	cpu_if->vgic_ppi_priorityr[3] = read_sysreg_s(SYS_ICH_PPI_PRIORITYR3_EL2);
+	cpu_if->vgic_ppi_priorityr[4] = read_sysreg_s(SYS_ICH_PPI_PRIORITYR4_EL2);
+	cpu_if->vgic_ppi_priorityr[5] = read_sysreg_s(SYS_ICH_PPI_PRIORITYR5_EL2);
+	cpu_if->vgic_ppi_priorityr[6] = read_sysreg_s(SYS_ICH_PPI_PRIORITYR6_EL2);
+	cpu_if->vgic_ppi_priorityr[7] = read_sysreg_s(SYS_ICH_PPI_PRIORITYR7_EL2);
+
+	if (VGIC_V5_NR_PRIVATE_IRQS == 128) {
+		bitmap_write(host_data_ptr(vgic_v5_ppi_state)->activer_exit,
+			     read_sysreg_s(SYS_ICH_PPI_ACTIVER1_EL2), 64, 64);
+		bitmap_write(host_data_ptr(vgic_v5_ppi_state)->enabler_exit,
+			     read_sysreg_s(SYS_ICH_PPI_ENABLER1_EL2), 64, 64);
+		bitmap_write(host_data_ptr(vgic_v5_ppi_state)->pendr_exit,
+			     read_sysreg_s(SYS_ICH_PPI_PENDR1_EL2), 64, 64);
+
+		cpu_if->vgic_ppi_priorityr[8] = read_sysreg_s(SYS_ICH_PPI_PRIORITYR8_EL2);
+		cpu_if->vgic_ppi_priorityr[9] = read_sysreg_s(SYS_ICH_PPI_PRIORITYR9_EL2);
+		cpu_if->vgic_ppi_priorityr[10] = read_sysreg_s(SYS_ICH_PPI_PRIORITYR10_EL2);
+		cpu_if->vgic_ppi_priorityr[11] = read_sysreg_s(SYS_ICH_PPI_PRIORITYR11_EL2);
+		cpu_if->vgic_ppi_priorityr[12] = read_sysreg_s(SYS_ICH_PPI_PRIORITYR12_EL2);
+		cpu_if->vgic_ppi_priorityr[13] = read_sysreg_s(SYS_ICH_PPI_PRIORITYR13_EL2);
+		cpu_if->vgic_ppi_priorityr[14] = read_sysreg_s(SYS_ICH_PPI_PRIORITYR14_EL2);
+		cpu_if->vgic_ppi_priorityr[15] = read_sysreg_s(SYS_ICH_PPI_PRIORITYR15_EL2);
+	}
+
+	/* Now that we are done, disable DVI */
+	write_sysreg_s(0, SYS_ICH_PPI_DVIR0_EL2);
+	write_sysreg_s(0, SYS_ICH_PPI_DVIR1_EL2);
+}
+
+void __vgic_v5_restore_ppi_state(struct vgic_v5_cpu_if *cpu_if)
+{
+	DECLARE_BITMAP(pendr, VGIC_V5_NR_PRIVATE_IRQS);
+
+	/* We assume 64 or 128 PPIs - see above comment */
+	BUILD_BUG_ON(VGIC_V5_NR_PRIVATE_IRQS % 64);
+
+	/* Enable DVI so that the guest's interrupt config takes over */
+	write_sysreg_s(bitmap_read(cpu_if->vgic_ppi_dvir, 0, 64),
+		       SYS_ICH_PPI_DVIR0_EL2);
+
+	write_sysreg_s(bitmap_read(cpu_if->vgic_ppi_activer, 0, 64),
+		       SYS_ICH_PPI_ACTIVER0_EL2);
+	write_sysreg_s(bitmap_read(cpu_if->vgic_ppi_enabler, 0, 64),
+		       SYS_ICH_PPI_ENABLER0_EL2);
+
+	/* Update the pending state of the NON-DVI'd PPIs, only */
+	bitmap_andnot(pendr, host_data_ptr(vgic_v5_ppi_state)->pendr_entry,
+		      cpu_if->vgic_ppi_dvir, VGIC_V5_NR_PRIVATE_IRQS);
+	write_sysreg_s(bitmap_read(pendr, 0, 64), SYS_ICH_PPI_PENDR0_EL2);
+
+	write_sysreg_s(cpu_if->vgic_ppi_priorityr[0],
+		       SYS_ICH_PPI_PRIORITYR0_EL2);
+	write_sysreg_s(cpu_if->vgic_ppi_priorityr[1],
+		       SYS_ICH_PPI_PRIORITYR1_EL2);
+	write_sysreg_s(cpu_if->vgic_ppi_priorityr[2],
+		       SYS_ICH_PPI_PRIORITYR2_EL2);
+	write_sysreg_s(cpu_if->vgic_ppi_priorityr[3],
+		       SYS_ICH_PPI_PRIORITYR3_EL2);
+	write_sysreg_s(cpu_if->vgic_ppi_priorityr[4],
+		       SYS_ICH_PPI_PRIORITYR4_EL2);
+	write_sysreg_s(cpu_if->vgic_ppi_priorityr[5],
+		       SYS_ICH_PPI_PRIORITYR5_EL2);
+	write_sysreg_s(cpu_if->vgic_ppi_priorityr[6],
+		       SYS_ICH_PPI_PRIORITYR6_EL2);
+	write_sysreg_s(cpu_if->vgic_ppi_priorityr[7],
+		       SYS_ICH_PPI_PRIORITYR7_EL2);
+
+	if (VGIC_V5_NR_PRIVATE_IRQS == 128) {
+		/* Enable DVI so that the guest's interrupt config takes over */
+		write_sysreg_s(bitmap_read(cpu_if->vgic_ppi_dvir, 64, 64),
+			       SYS_ICH_PPI_DVIR1_EL2);
+
+		write_sysreg_s(bitmap_read(cpu_if->vgic_ppi_activer, 64, 64),
+			       SYS_ICH_PPI_ACTIVER1_EL2);
+		write_sysreg_s(bitmap_read(cpu_if->vgic_ppi_enabler, 64, 64),
+			       SYS_ICH_PPI_ENABLER1_EL2);
+		write_sysreg_s(bitmap_read(pendr, 64, 64),
+			       SYS_ICH_PPI_PENDR1_EL2);
+
+		write_sysreg_s(cpu_if->vgic_ppi_priorityr[8],
+			       SYS_ICH_PPI_PRIORITYR8_EL2);
+		write_sysreg_s(cpu_if->vgic_ppi_priorityr[9],
+			       SYS_ICH_PPI_PRIORITYR9_EL2);
+		write_sysreg_s(cpu_if->vgic_ppi_priorityr[10],
+			       SYS_ICH_PPI_PRIORITYR10_EL2);
+		write_sysreg_s(cpu_if->vgic_ppi_priorityr[11],
+			       SYS_ICH_PPI_PRIORITYR11_EL2);
+		write_sysreg_s(cpu_if->vgic_ppi_priorityr[12],
+			       SYS_ICH_PPI_PRIORITYR12_EL2);
+		write_sysreg_s(cpu_if->vgic_ppi_priorityr[13],
+			       SYS_ICH_PPI_PRIORITYR13_EL2);
+		write_sysreg_s(cpu_if->vgic_ppi_priorityr[14],
+			       SYS_ICH_PPI_PRIORITYR14_EL2);
+		write_sysreg_s(cpu_if->vgic_ppi_priorityr[15],
+			       SYS_ICH_PPI_PRIORITYR15_EL2);
+	} else {
+		write_sysreg_s(0, SYS_ICH_PPI_DVIR1_EL2);
+
+		write_sysreg_s(0, SYS_ICH_PPI_ACTIVER1_EL2);
+		write_sysreg_s(0, SYS_ICH_PPI_ENABLER1_EL2);
+		write_sysreg_s(0, SYS_ICH_PPI_PENDR1_EL2);
+
+		write_sysreg_s(0, SYS_ICH_PPI_PRIORITYR8_EL2);
+		write_sysreg_s(0, SYS_ICH_PPI_PRIORITYR9_EL2);
+		write_sysreg_s(0, SYS_ICH_PPI_PRIORITYR10_EL2);
+		write_sysreg_s(0, SYS_ICH_PPI_PRIORITYR11_EL2);
+		write_sysreg_s(0, SYS_ICH_PPI_PRIORITYR12_EL2);
+		write_sysreg_s(0, SYS_ICH_PPI_PRIORITYR13_EL2);
+		write_sysreg_s(0, SYS_ICH_PPI_PRIORITYR14_EL2);
+		write_sysreg_s(0, SYS_ICH_PPI_PRIORITYR15_EL2);
+	}
+}
+
+void __vgic_v5_save_state(struct vgic_v5_cpu_if *cpu_if)
+{
+	cpu_if->vgic_vmcr = read_sysreg_s(SYS_ICH_VMCR_EL2);
+	cpu_if->vgic_icsr = read_sysreg_s(SYS_ICC_ICSR_EL1);
+}
+
+void __vgic_v5_restore_state(struct vgic_v5_cpu_if *cpu_if)
+{
+	write_sysreg_s(cpu_if->vgic_icsr, SYS_ICC_ICSR_EL1);
+}
diff --git a/arch/arm64/kvm/hyp/vhe/Makefile b/arch/arm64/kvm/hyp/vhe/Makefile
index afc4aed9231ac..9695328bbd96e 100644
--- a/arch/arm64/kvm/hyp/vhe/Makefile
+++ b/arch/arm64/kvm/hyp/vhe/Makefile
@@ -10,4 +10,4 @@ CFLAGS_switch.o += -Wno-override-init
 
 obj-y := timer-sr.o sysreg-sr.o debug-sr.o switch.o tlb.o
 obj-y += ../vgic-v3-sr.o ../aarch32.o ../vgic-v2-cpuif-proxy.o ../entry.o \
-	 ../fpsimd.o ../hyp-entry.o ../exception.o
+	 ../fpsimd.o ../hyp-entry.o ../exception.o ../vgic-v5-sr.o
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 24969fa8d02d6..07e394690dccb 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -428,6 +428,27 @@ struct vgic_v3_cpu_if {
 	unsigned int used_lrs;
 };
 
+struct vgic_v5_cpu_if {
+	u64	vgic_apr;
+	u64	vgic_vmcr;
+
+	/* PPI register state */
+	DECLARE_BITMAP(vgic_ppi_dvir, VGIC_V5_NR_PRIVATE_IRQS);
+	DECLARE_BITMAP(vgic_ppi_activer, VGIC_V5_NR_PRIVATE_IRQS);
+	DECLARE_BITMAP(vgic_ppi_enabler, VGIC_V5_NR_PRIVATE_IRQS);
+	/* We have one byte (of which 5 bits are used) per PPI for priority */
+	u64	vgic_ppi_priorityr[VGIC_V5_NR_PRIVATE_IRQS / 8];
+
+	/*
+	 * The ICSR is re-used across host and guest, and hence it needs to be
+	 * saved/restored. Only one copy is required as the host should block
+	 * preemption between executing GIC CDRCFG and acccessing the
+	 * ICC_ICSR_EL1. A guest, of course, can never guarantee this, and hence
+	 * it is the hyp's responsibility to keep the state constistent.
+	 */
+	u64	vgic_icsr;
+};
+
 /* What PPI capabilities does a GICv5 host have */
 struct vgic_v5_ppi_caps {
 	DECLARE_BITMAP(impl_ppi_mask, VGIC_V5_NR_PRIVATE_IRQS);
@@ -438,6 +459,7 @@ struct vgic_cpu {
 	union {
 		struct vgic_v2_cpu_if	vgic_v2;
 		struct vgic_v3_cpu_if	vgic_v3;
+		struct vgic_v5_cpu_if	vgic_v5;
 	};
 
 	struct vgic_irq *private_irqs;
-- 
2.34.1

[PATCH v6 16/39] KVM: arm64: gic-v5: Implement GICv5 load/put and save/restore

[Sascha Bischoff]

This change introduces GICv5 load/put. Additionally, it plumbs in
save/restore for:

* PPIs (ICH_PPI_x_EL2 regs)
* ICH_VMCR_EL2
* ICH_APR_EL2
* ICC_ICSR_EL1

A GICv5-specific enable bit is added to struct vgic_vmcr as this
differs from previous GICs. On GICv5-native systems, the VMCR only
contains the enable bit (driven by the guest via ICC_CR0_EL1.EN) and
the priority mask (PCR).

A struct gicv5_vpe is also introduced. This currently only contains a
single field - bool resident - which is used to track if a VPE is
currently running or not, and is used to avoid a case of double load
or double put on the WFI path for a vCPU. This struct will be extended
as additional GICv5 support is merged, specifically for VPE doorbells.

Co-authored-by: Timothy Hayes <timothy.hayes@arm.com>
Signed-off-by: Timothy Hayes <timothy.hayes@arm.com>
Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
---
 arch/arm64/kvm/hyp/nvhe/switch.c   | 12 +++++
 arch/arm64/kvm/vgic/vgic-mmio.c    | 40 +++++++++++++---
 arch/arm64/kvm/vgic/vgic-v5.c      | 74 ++++++++++++++++++++++++++++++
 arch/arm64/kvm/vgic/vgic.c         | 74 ++++++++++++++++++++++++------
 arch/arm64/kvm/vgic/vgic.h         |  7 +++
 include/kvm/arm_vgic.h             |  2 +
 include/linux/irqchip/arm-gic-v5.h |  5 ++
 7 files changed, 193 insertions(+), 21 deletions(-)

diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c
index b41485ce295ab..a88da302b6d08 100644
--- a/arch/arm64/kvm/hyp/nvhe/switch.c
+++ b/arch/arm64/kvm/hyp/nvhe/switch.c
@@ -113,6 +113,12 @@ static void __deactivate_traps(struct kvm_vcpu *vcpu)
 /* Save VGICv3 state on non-VHE systems */
 static void __hyp_vgic_save_state(struct kvm_vcpu *vcpu)
 {
+	if (vgic_is_v5(kern_hyp_va(vcpu->kvm))) {
+		__vgic_v5_save_state(&vcpu->arch.vgic_cpu.vgic_v5);
+		__vgic_v5_save_ppi_state(&vcpu->arch.vgic_cpu.vgic_v5);
+		return;
+	}
+
 	if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) {
 		__vgic_v3_save_state(&vcpu->arch.vgic_cpu.vgic_v3);
 		__vgic_v3_deactivate_traps(&vcpu->arch.vgic_cpu.vgic_v3);
@@ -122,6 +128,12 @@ static void __hyp_vgic_save_state(struct kvm_vcpu *vcpu)
 /* Restore VGICv3 state on non-VHE systems */
 static void __hyp_vgic_restore_state(struct kvm_vcpu *vcpu)
 {
+	if (vgic_is_v5(kern_hyp_va(vcpu->kvm))) {
+		__vgic_v5_restore_state(&vcpu->arch.vgic_cpu.vgic_v5);
+		__vgic_v5_restore_ppi_state(&vcpu->arch.vgic_cpu.vgic_v5);
+		return;
+	}
+
 	if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) {
 		__vgic_v3_activate_traps(&vcpu->arch.vgic_cpu.vgic_v3);
 		__vgic_v3_restore_state(&vcpu->arch.vgic_cpu.vgic_v3);
diff --git a/arch/arm64/kvm/vgic/vgic-mmio.c b/arch/arm64/kvm/vgic/vgic-mmio.c
index a573b1f0c6cbe..74d76dec97304 100644
--- a/arch/arm64/kvm/vgic/vgic-mmio.c
+++ b/arch/arm64/kvm/vgic/vgic-mmio.c
@@ -842,18 +842,46 @@ vgic_find_mmio_region(const struct vgic_register_region *regions,
 
 void vgic_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr)
 {
-	if (kvm_vgic_global_state.type == VGIC_V2)
-		vgic_v2_set_vmcr(vcpu, vmcr);
-	else
+	const struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+
+	switch (dist->vgic_model) {
+	case KVM_DEV_TYPE_ARM_VGIC_V5:
+		vgic_v5_set_vmcr(vcpu, vmcr);
+		break;
+	case KVM_DEV_TYPE_ARM_VGIC_V3:
 		vgic_v3_set_vmcr(vcpu, vmcr);
+		break;
+	case KVM_DEV_TYPE_ARM_VGIC_V2:
+		if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
+			vgic_v3_set_vmcr(vcpu, vmcr);
+		else
+			vgic_v2_set_vmcr(vcpu, vmcr);
+		break;
+	default:
+		BUG();
+	}
 }
 
 void vgic_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr)
 {
-	if (kvm_vgic_global_state.type == VGIC_V2)
-		vgic_v2_get_vmcr(vcpu, vmcr);
-	else
+	const struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+
+	switch (dist->vgic_model) {
+	case KVM_DEV_TYPE_ARM_VGIC_V5:
+		vgic_v5_get_vmcr(vcpu, vmcr);
+		break;
+	case KVM_DEV_TYPE_ARM_VGIC_V3:
 		vgic_v3_get_vmcr(vcpu, vmcr);
+		break;
+	case KVM_DEV_TYPE_ARM_VGIC_V2:
+		if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
+			vgic_v3_get_vmcr(vcpu, vmcr);
+		else
+			vgic_v2_get_vmcr(vcpu, vmcr);
+		break;
+	default:
+		BUG();
+	}
 }
 
 /*
diff --git a/arch/arm64/kvm/vgic/vgic-v5.c b/arch/arm64/kvm/vgic/vgic-v5.c
index cf8382a954bbc..41317e1d94a2f 100644
--- a/arch/arm64/kvm/vgic/vgic-v5.c
+++ b/arch/arm64/kvm/vgic/vgic-v5.c
@@ -86,3 +86,77 @@ int vgic_v5_probe(const struct gic_kvm_info *info)
 
 	return 0;
 }
+
+void vgic_v5_load(struct kvm_vcpu *vcpu)
+{
+	struct vgic_v5_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v5;
+
+	/*
+	 * On the WFI path, vgic_load is called a second time. The first is when
+	 * scheduling in the vcpu thread again, and the second is when leaving
+	 * WFI. Skip the second instance as it serves no purpose and just
+	 * restores the same state again.
+	 */
+	if (cpu_if->gicv5_vpe.resident)
+		return;
+
+	kvm_call_hyp(__vgic_v5_restore_vmcr_apr, cpu_if);
+
+	cpu_if->gicv5_vpe.resident = true;
+}
+
+void vgic_v5_put(struct kvm_vcpu *vcpu)
+{
+	struct vgic_v5_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v5;
+
+	/*
+	 * Do nothing if we're not resident. This can happen in the WFI path
+	 * where we do a vgic_put in the WFI path and again later when
+	 * descheduling the thread. We risk losing VMCR state if we sync it
+	 * twice, so instead return early in this case.
+	 */
+	if (!cpu_if->gicv5_vpe.resident)
+		return;
+
+	kvm_call_hyp(__vgic_v5_save_apr, cpu_if);
+
+	cpu_if->gicv5_vpe.resident = false;
+}
+
+void vgic_v5_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcrp)
+{
+	struct vgic_v5_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v5;
+	u64 vmcr = cpu_if->vgic_vmcr;
+
+	vmcrp->en = FIELD_GET(FEAT_GCIE_ICH_VMCR_EL2_EN, vmcr);
+	vmcrp->pmr = FIELD_GET(FEAT_GCIE_ICH_VMCR_EL2_VPMR, vmcr);
+}
+
+void vgic_v5_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcrp)
+{
+	struct vgic_v5_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v5;
+	u64 vmcr;
+
+	vmcr = FIELD_PREP(FEAT_GCIE_ICH_VMCR_EL2_VPMR, vmcrp->pmr) |
+	       FIELD_PREP(FEAT_GCIE_ICH_VMCR_EL2_EN, vmcrp->en);
+
+	cpu_if->vgic_vmcr = vmcr;
+}
+
+void vgic_v5_restore_state(struct kvm_vcpu *vcpu)
+{
+	struct vgic_v5_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v5;
+
+	__vgic_v5_restore_state(cpu_if);
+	__vgic_v5_restore_ppi_state(cpu_if);
+	dsb(sy);
+}
+
+void vgic_v5_save_state(struct kvm_vcpu *vcpu)
+{
+	struct vgic_v5_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v5;
+
+	__vgic_v5_save_state(cpu_if);
+	__vgic_v5_save_ppi_state(cpu_if);
+	dsb(sy);
+}
diff --git a/arch/arm64/kvm/vgic/vgic.c b/arch/arm64/kvm/vgic/vgic.c
index d95fbf20002f4..6df03d0d55078 100644
--- a/arch/arm64/kvm/vgic/vgic.c
+++ b/arch/arm64/kvm/vgic/vgic.c
@@ -1028,7 +1028,10 @@ static inline bool can_access_vgic_from_kernel(void)
 
 static inline void vgic_save_state(struct kvm_vcpu *vcpu)
 {
-	if (!static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
+	/* No switch statement here. See comment in vgic_restore_state() */
+	if (vgic_is_v5(vcpu->kvm))
+		vgic_v5_save_state(vcpu);
+	else if (!static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
 		vgic_v2_save_state(vcpu);
 	else
 		__vgic_v3_save_state(&vcpu->arch.vgic_cpu.vgic_v3);
@@ -1037,14 +1040,16 @@ static inline void vgic_save_state(struct kvm_vcpu *vcpu)
 /* Sync back the hardware VGIC state into our emulation after a guest's run. */
 void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu)
 {
-	/* If nesting, emulate the HW effect from L0 to L1 */
-	if (vgic_state_is_nested(vcpu)) {
-		vgic_v3_sync_nested(vcpu);
-		return;
-	}
+	if (vgic_is_v3(vcpu->kvm)) {
+		/* If nesting, emulate the HW effect from L0 to L1 */
+		if (vgic_state_is_nested(vcpu)) {
+			vgic_v3_sync_nested(vcpu);
+			return;
+		}
 
-	if (vcpu_has_nv(vcpu))
-		vgic_v3_nested_update_mi(vcpu);
+		if (vcpu_has_nv(vcpu))
+			vgic_v3_nested_update_mi(vcpu);
+	}
 
 	if (can_access_vgic_from_kernel())
 		vgic_save_state(vcpu);
@@ -1066,7 +1071,18 @@ void kvm_vgic_process_async_update(struct kvm_vcpu *vcpu)
 
 static inline void vgic_restore_state(struct kvm_vcpu *vcpu)
 {
-	if (!static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
+	/*
+	 * As nice as it would be to restructure this code into a switch
+	 * statement as can be found elsewhere, the logic quickly gets ugly.
+	 *
+	 * __vgic_v3_restore_state() is doing a lot of heavy lifting here. It is
+	 * required for GICv3-on-GICv3, GICv2-on-GICv3, GICv3-on-GICv5, and the
+	 * no-in-kernel-irqchip case on GICv3 hardware. Hence, adding a switch
+	 * here results in much more complex code.
+	 */
+	if (vgic_is_v5(vcpu->kvm))
+		vgic_v5_restore_state(vcpu);
+	else if (!static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
 		vgic_v2_restore_state(vcpu);
 	else
 		__vgic_v3_restore_state(&vcpu->arch.vgic_cpu.vgic_v3);
@@ -1120,30 +1136,58 @@ void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu)
 
 void kvm_vgic_load(struct kvm_vcpu *vcpu)
 {
+	const struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+
 	if (unlikely(!irqchip_in_kernel(vcpu->kvm) || !vgic_initialized(vcpu->kvm))) {
 		if (has_vhe() && static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
 			__vgic_v3_activate_traps(&vcpu->arch.vgic_cpu.vgic_v3);
 		return;
 	}
 
-	if (!static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
-		vgic_v2_load(vcpu);
-	else
+	switch (dist->vgic_model) {
+	case KVM_DEV_TYPE_ARM_VGIC_V5:
+		vgic_v5_load(vcpu);
+		break;
+	case KVM_DEV_TYPE_ARM_VGIC_V3:
 		vgic_v3_load(vcpu);
+		break;
+	case KVM_DEV_TYPE_ARM_VGIC_V2:
+		if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
+			vgic_v3_load(vcpu);
+		else
+			vgic_v2_load(vcpu);
+		break;
+	default:
+		BUG();
+	}
 }
 
 void kvm_vgic_put(struct kvm_vcpu *vcpu)
 {
+	const struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+
 	if (unlikely(!irqchip_in_kernel(vcpu->kvm) || !vgic_initialized(vcpu->kvm))) {
 		if (has_vhe() && static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
 			__vgic_v3_deactivate_traps(&vcpu->arch.vgic_cpu.vgic_v3);
 		return;
 	}
 
-	if (!static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
-		vgic_v2_put(vcpu);
-	else
+	switch (dist->vgic_model) {
+	case KVM_DEV_TYPE_ARM_VGIC_V5:
+		vgic_v5_put(vcpu);
+		break;
+	case KVM_DEV_TYPE_ARM_VGIC_V3:
 		vgic_v3_put(vcpu);
+		break;
+	case KVM_DEV_TYPE_ARM_VGIC_V2:
+		if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
+			vgic_v3_put(vcpu);
+		else
+			vgic_v2_put(vcpu);
+		break;
+	default:
+		BUG();
+	}
 }
 
 int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu)
diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h
index 7b7eed69d7973..cc487a69d0389 100644
--- a/arch/arm64/kvm/vgic/vgic.h
+++ b/arch/arm64/kvm/vgic/vgic.h
@@ -187,6 +187,7 @@ static inline u64 vgic_ich_hcr_trap_bits(void)
  * registers regardless of the hardware backed GIC used.
  */
 struct vgic_vmcr {
+	u32	en; /* GICv5-specific */
 	u32	grpen0;
 	u32	grpen1;
 
@@ -363,6 +364,12 @@ void vgic_debug_init(struct kvm *kvm);
 void vgic_debug_destroy(struct kvm *kvm);
 
 int vgic_v5_probe(const struct gic_kvm_info *info);
+void vgic_v5_load(struct kvm_vcpu *vcpu);
+void vgic_v5_put(struct kvm_vcpu *vcpu);
+void vgic_v5_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr);
+void vgic_v5_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr);
+void vgic_v5_restore_state(struct kvm_vcpu *vcpu);
+void vgic_v5_save_state(struct kvm_vcpu *vcpu);
 
 static inline int vgic_v3_max_apr_idx(struct kvm_vcpu *vcpu)
 {
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 07e394690dccb..b27bfc463a311 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -447,6 +447,8 @@ struct vgic_v5_cpu_if {
 	 * it is the hyp's responsibility to keep the state constistent.
 	 */
 	u64	vgic_icsr;
+
+	struct gicv5_vpe gicv5_vpe;
 };
 
 /* What PPI capabilities does a GICv5 host have */
diff --git a/include/linux/irqchip/arm-gic-v5.h b/include/linux/irqchip/arm-gic-v5.h
index b1566a7c93ecb..40d2fce682940 100644
--- a/include/linux/irqchip/arm-gic-v5.h
+++ b/include/linux/irqchip/arm-gic-v5.h
@@ -387,6 +387,11 @@ int gicv5_spi_irq_set_type(struct irq_data *d, unsigned int type);
 int gicv5_irs_iste_alloc(u32 lpi);
 void gicv5_irs_syncr(void);
 
+/* Embedded in kvm.arch */
+struct gicv5_vpe {
+	bool			resident;
+};
+
 struct gicv5_its_devtab_cfg {
 	union {
 		struct {
-- 
2.34.1

[PATCH v6 17/39] KVM: arm64: gic-v5: Finalize GICv5 PPIs and generate mask

[Sascha Bischoff]

We only want to expose a subset of the PPIs to a guest. If a PPI does
not have an owner, it is not being actively driven by a device. The
SW_PPI is a special case, as it is likely for userspace to wish to
inject that.

Therefore, just prior to running the guest for the first time, we need
to finalize the PPIs. A mask is generated which, when combined with
trapping a guest's PPI accesses, allows for the guest's view of the
PPI to be filtered. This mask is global to the VM as all VCPUs PPI
configurations must match.

In addition, the PPI HMR is calculated.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
---
 arch/arm64/kvm/arm.c          |  4 ++++
 arch/arm64/kvm/vgic/vgic-v5.c | 35 +++++++++++++++++++++++++++++++++++
 include/kvm/arm_vgic.h        | 24 ++++++++++++++++++++++++
 3 files changed, 63 insertions(+)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index aa69fd5b372fd..5bbc1adb705e2 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -934,6 +934,10 @@ int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu)
 			return ret;
 	}
 
+	ret = vgic_v5_finalize_ppi_state(kvm);
+	if (ret)
+		return ret;
+
 	if (is_protected_kvm_enabled()) {
 		ret = pkvm_create_hyp_vm(kvm);
 		if (ret)
diff --git a/arch/arm64/kvm/vgic/vgic-v5.c b/arch/arm64/kvm/vgic/vgic-v5.c
index 41317e1d94a2f..07f416fbc4bc8 100644
--- a/arch/arm64/kvm/vgic/vgic-v5.c
+++ b/arch/arm64/kvm/vgic/vgic-v5.c
@@ -87,6 +87,41 @@ int vgic_v5_probe(const struct gic_kvm_info *info)
 	return 0;
 }
 
+int vgic_v5_finalize_ppi_state(struct kvm *kvm)
+{
+	struct kvm_vcpu *vcpu0;
+	int i;
+
+	if (!vgic_is_v5(kvm))
+		return 0;
+
+	/* The PPI state for all VCPUs should be the same. Pick the first. */
+	vcpu0 = kvm_get_vcpu(kvm, 0);
+
+	bitmap_zero(kvm->arch.vgic.gicv5_vm.vgic_ppi_mask, VGIC_V5_NR_PRIVATE_IRQS);
+	bitmap_zero(kvm->arch.vgic.gicv5_vm.vgic_ppi_hmr, VGIC_V5_NR_PRIVATE_IRQS);
+
+	for_each_set_bit(i, ppi_caps.impl_ppi_mask, VGIC_V5_NR_PRIVATE_IRQS) {
+		const u32 intid = vgic_v5_make_ppi(i);
+		struct vgic_irq *irq;
+
+		irq = vgic_get_vcpu_irq(vcpu0, intid);
+
+		/* Expose PPIs with an owner or the SW_PPI, only */
+		scoped_guard(raw_spinlock_irqsave, &irq->irq_lock) {
+			if (irq->owner || i == GICV5_ARCH_PPI_SW_PPI) {
+				__assign_bit(i, kvm->arch.vgic.gicv5_vm.vgic_ppi_mask, 1);
+				__assign_bit(i, kvm->arch.vgic.gicv5_vm.vgic_ppi_hmr,
+					     irq->config == VGIC_CONFIG_LEVEL);
+			}
+		}
+
+		vgic_put_irq(vcpu0->kvm, irq);
+	}
+
+	return 0;
+}
+
 void vgic_v5_load(struct kvm_vcpu *vcpu)
 {
 	struct vgic_v5_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v5;
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index b27bfc463a311..fdad0263499ba 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -326,6 +326,23 @@ struct vgic_redist_region {
 	struct list_head list;
 };
 
+struct vgic_v5_vm {
+	/*
+	 * We only expose a subset of PPIs to the guest. This subset is a
+	 * combination of the PPIs that are actually implemented and what we
+	 * actually choose to expose.
+	 */
+	DECLARE_BITMAP(vgic_ppi_mask, VGIC_V5_NR_PRIVATE_IRQS);
+
+	/*
+	 * The HMR itself is handled by the hardware, but we still need to have
+	 * a mask that we can use when merging in pending state (only the state
+	 * of Edge PPIs is merged back in from the guest an the HMR provides a
+	 * convenient way to do that).
+	 */
+	DECLARE_BITMAP(vgic_ppi_hmr, VGIC_V5_NR_PRIVATE_IRQS);
+};
+
 struct vgic_dist {
 	bool			in_kernel;
 	bool			ready;
@@ -398,6 +415,11 @@ struct vgic_dist {
 	 * else.
 	 */
 	struct its_vm		its_vm;
+
+	/*
+	 * GICv5 per-VM data.
+	 */
+	struct vgic_v5_vm	gicv5_vm;
 };
 
 struct vgic_v2_cpu_if {
@@ -588,6 +610,8 @@ int vgic_v4_load(struct kvm_vcpu *vcpu);
 void vgic_v4_commit(struct kvm_vcpu *vcpu);
 int vgic_v4_put(struct kvm_vcpu *vcpu);
 
+int vgic_v5_finalize_ppi_state(struct kvm *kvm);
+
 bool vgic_state_is_nested(struct kvm_vcpu *vcpu);
 
 /* CPU HP callbacks */
-- 
2.34.1

[PATCH v6 18/39] KVM: arm64: gic: Introduce queue_irq_unlock to irq_ops

[Sascha Bischoff]

There are times when the default behaviour of vgic_queue_irq_unlock()
is undesirable. This is because some GICs, such a GICv5 which is the
main driver for this change, handle the majority of the interrupt
lifecycle in hardware. In this case, there is no need for a per-VCPU
AP list as the interrupt can be made pending directly. This is done
either via the ICH_PPI_x_EL2 registers for PPIs, or with the VDPEND
system instruction for SPIs and LPIs.

The vgic_queue_irq_unlock() function is made overridable using a new
function pointer in struct irq_ops. vgic_queue_irq_unlock() is
overridden if the function pointer is non-null.

This new irq_op is unused in this change - it is purely providing the
infrastructure itself. The subsequent PPI injection changes provide a
demonstration of the usage of the queue_irq_unlock irq_op.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
---
 arch/arm64/kvm/vgic/vgic.c | 3 +++
 include/kvm/arm_vgic.h     | 8 ++++++++
 2 files changed, 11 insertions(+)

diff --git a/arch/arm64/kvm/vgic/vgic.c b/arch/arm64/kvm/vgic/vgic.c
index 6df03d0d55078..f3677535200ff 100644
--- a/arch/arm64/kvm/vgic/vgic.c
+++ b/arch/arm64/kvm/vgic/vgic.c
@@ -404,6 +404,9 @@ bool vgic_queue_irq_unlock(struct kvm *kvm, struct vgic_irq *irq,
 
 	lockdep_assert_held(&irq->irq_lock);
 
+	if (irq->ops && irq->ops->queue_irq_unlock)
+		return irq->ops->queue_irq_unlock(kvm, irq, flags);
+
 retry:
 	vcpu = vgic_target_oracle(irq);
 	if (irq->vcpu || !vcpu) {
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index fdad0263499ba..e9797c5dbbf0c 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -189,6 +189,8 @@ enum vgic_irq_config {
 	VGIC_CONFIG_LEVEL
 };
 
+struct vgic_irq;
+
 /*
  * Per-irq ops overriding some common behavious.
  *
@@ -207,6 +209,12 @@ struct irq_ops {
 	 * peaking into the physical GIC.
 	 */
 	bool (*get_input_level)(int vintid);
+
+	/*
+	 * Function pointer to override the queuing of an IRQ.
+	 */
+	bool (*queue_irq_unlock)(struct kvm *kvm, struct vgic_irq *irq,
+				unsigned long flags) __releases(&irq->irq_lock);
 };
 
 struct vgic_irq {
-- 
2.34.1

[PATCH v6 19/39] KVM: arm64: gic-v5: Implement PPI interrupt injection

[Sascha Bischoff]

This change introduces interrupt injection for PPIs for GICv5-based
guests.

The lifecycle of PPIs is largely managed by the hardware for a GICv5
system. The hypervisor injects pending state into the guest by using
the ICH_PPI_PENDRx_EL2 registers. These are used by the hardware to
pick a Highest Priority Pending Interrupt (HPPI) for the guest based
on the enable state of each individual interrupt. The enable state and
priority for each interrupt are provided by the guest itself (through
writes to the PPI registers).

When Direct Virtual Interrupt (DVI) is set for a particular PPI, the
hypervisor is even able to skip the injection of the pending state
altogether - it all happens in hardware.

The result of the above is that no AP lists are required for GICv5,
unlike for older GICs. Instead, for PPIs the ICH_PPI_* registers
fulfil the same purpose for all 128 PPIs. Hence, as long as the
ICH_PPI_* registers are populated prior to guest entry, and merged
back into the KVM shadow state on exit, the PPI state is preserved,
and interrupts can be injected.

When injecting the state of a PPI the state is merged into the
PPI-specific vgic_irq structure. The PPIs are made pending via the
ICH_PPI_PENDRx_EL2 registers, the value of which is generated from the
vgic_irq structures for each PPI exposed on guest entry. The
queue_irq_unlock() irq_op is required to kick the vCPU to ensure that
it seems the new state. The result is that no AP lists are used for
private interrupts on GICv5.

Prior to entering the guest, vgic_v5_flush_ppi_state() is called from
kvm_vgic_flush_hwstate(). This generates the pending state to inject
into the guest, and snapshots it (twice - an entry and an exit copy)
in order to track any changes. These changes can come from a guest
consuming an interrupt or from a guest making an Edge-triggered
interrupt pending.

When returning from running a guest, the guest's PPI state is merged
back into KVM's vgic_irq state in vgic_v5_merge_ppi_state() from
kvm_vgic_sync_hwstate(). The Enable and Active state is synced back for
all PPIs, and the pending state is synced back for Edge PPIs (Level is
driven directly by the devices generating said levels). The incoming
pending state from the guest is merged with KVM's shadow state to
avoid losing any incoming interrupts.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
---
 arch/arm64/kvm/vgic/vgic-v5.c | 143 ++++++++++++++++++++++++++++++++++
 arch/arm64/kvm/vgic/vgic.c    |  41 ++++++++--
 arch/arm64/kvm/vgic/vgic.h    |  25 +++---
 3 files changed, 194 insertions(+), 15 deletions(-)

diff --git a/arch/arm64/kvm/vgic/vgic-v5.c b/arch/arm64/kvm/vgic/vgic-v5.c
index 07f416fbc4bc8..e080fce61dc35 100644
--- a/arch/arm64/kvm/vgic/vgic-v5.c
+++ b/arch/arm64/kvm/vgic/vgic-v5.c
@@ -122,6 +122,149 @@ int vgic_v5_finalize_ppi_state(struct kvm *kvm)
 	return 0;
 }
 
+/*
+ * For GICv5, the PPIs are mostly directly managed by the hardware. We (the
+ * hypervisor) handle the pending, active, enable state save/restore, but don't
+ * need the PPIs to be queued on a per-VCPU AP list. Therefore, sanity check the
+ * state, unlock, and return.
+ */
+static bool vgic_v5_ppi_queue_irq_unlock(struct kvm *kvm, struct vgic_irq *irq,
+					 unsigned long flags)
+	__releases(&irq->irq_lock)
+{
+	struct kvm_vcpu *vcpu;
+
+	lockdep_assert_held(&irq->irq_lock);
+
+	if (WARN_ON_ONCE(!__irq_is_ppi(KVM_DEV_TYPE_ARM_VGIC_V5, irq->intid)))
+		goto out_unlock_fail;
+
+	vcpu = irq->target_vcpu;
+	if (WARN_ON_ONCE(!vcpu))
+		goto out_unlock_fail;
+
+	raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
+
+	/* Directly kick the target VCPU to make sure it sees the IRQ */
+	kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
+	kvm_vcpu_kick(vcpu);
+
+	return true;
+
+out_unlock_fail:
+	raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
+
+	return false;
+}
+
+static struct irq_ops vgic_v5_ppi_irq_ops = {
+	.queue_irq_unlock = vgic_v5_ppi_queue_irq_unlock,
+};
+
+void vgic_v5_set_ppi_ops(struct vgic_irq *irq)
+{
+	if (WARN_ON(!irq))
+		return;
+
+	guard(raw_spinlock_irqsave)(&irq->irq_lock);
+
+	if (!WARN_ON(irq->ops))
+		irq->ops = &vgic_v5_ppi_irq_ops;
+}
+
+/*
+ * Detect any PPIs state changes, and propagate the state with KVM's
+ * shadow structures.
+ */
+void vgic_v5_fold_ppi_state(struct kvm_vcpu *vcpu)
+{
+	struct vgic_v5_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v5;
+	DECLARE_BITMAP(changed_active, VGIC_V5_NR_PRIVATE_IRQS);
+	DECLARE_BITMAP(changed_pending, VGIC_V5_NR_PRIVATE_IRQS);
+	DECLARE_BITMAP(changed_bits, VGIC_V5_NR_PRIVATE_IRQS);
+	unsigned long *activer, *pendr_entry, *pendr;
+	int i;
+
+	activer = host_data_ptr(vgic_v5_ppi_state)->activer_exit;
+	pendr_entry = host_data_ptr(vgic_v5_ppi_state)->pendr_entry;
+	pendr = host_data_ptr(vgic_v5_ppi_state)->pendr_exit;
+
+	bitmap_xor(changed_active, cpu_if->vgic_ppi_activer, activer,
+		   VGIC_V5_NR_PRIVATE_IRQS);
+	bitmap_xor(changed_pending, pendr_entry, pendr,
+		   VGIC_V5_NR_PRIVATE_IRQS);
+	bitmap_or(changed_bits, changed_active, changed_pending,
+		  VGIC_V5_NR_PRIVATE_IRQS);
+
+	for_each_set_bit (i, changed_bits, VGIC_V5_NR_PRIVATE_IRQS) {
+		u32 intid = vgic_v5_make_ppi(i);
+		struct vgic_irq *irq;
+
+		irq = vgic_get_vcpu_irq(vcpu, intid);
+
+		scoped_guard(raw_spinlock_irqsave, &irq->irq_lock) {
+			irq->active = test_bit(i, activer);
+
+			/* This is an OR to avoid losing incoming edges! */
+			if (irq->config == VGIC_CONFIG_EDGE)
+				irq->pending_latch |= test_bit(i, pendr);
+		}
+
+		vgic_put_irq(vcpu->kvm, irq);
+	}
+
+	/*
+	 * Re-inject the exit state as entry state next time!
+	 *
+	 * Note that the write of the Enable state is trapped, and hence there
+	 * is nothing to explcitly sync back here as we already have the latest
+	 * copy by definition.
+	 */
+	bitmap_copy(cpu_if->vgic_ppi_activer, activer, VGIC_V5_NR_PRIVATE_IRQS);
+}
+
+void vgic_v5_flush_ppi_state(struct kvm_vcpu *vcpu)
+{
+	DECLARE_BITMAP(pendr, VGIC_V5_NR_PRIVATE_IRQS);
+	int i;
+
+	/*
+	 * Time to enter the guest - we first need to build the guest's
+	 * ICC_PPI_PENDRx_EL1, however.
+	 */
+	bitmap_zero(pendr, VGIC_V5_NR_PRIVATE_IRQS);
+	for_each_set_bit(i, vcpu->kvm->arch.vgic.gicv5_vm.vgic_ppi_mask,
+			 VGIC_V5_NR_PRIVATE_IRQS) {
+		u32 intid = vgic_v5_make_ppi(i);
+		struct vgic_irq *irq;
+
+		irq = vgic_get_vcpu_irq(vcpu, intid);
+
+		scoped_guard(raw_spinlock_irqsave, &irq->irq_lock)
+			__assign_bit(i, pendr, irq_is_pending(irq));
+
+		vgic_put_irq(vcpu->kvm, irq);
+	}
+
+	/*
+	 * Copy the shadow state to the pending reg that will be written to the
+	 * ICH_PPI_PENDRx_EL2 regs. While the guest is running we track any
+	 * incoming changes to the pending state in the vgic_irq structures. The
+	 * incoming changes are merged with the outgoing changes on the return
+	 * path.
+	 */
+	bitmap_copy(host_data_ptr(vgic_v5_ppi_state)->pendr_entry, pendr,
+		    VGIC_V5_NR_PRIVATE_IRQS);
+
+	/*
+	 * Make sure that we can correctly detect "edges" in the PPI
+	 * state. There's a path where we never actually enter the guest, and
+	 * failure to do this risks losing pending state
+	 */
+	bitmap_copy(host_data_ptr(vgic_v5_ppi_state)->pendr_exit, pendr,
+		    VGIC_V5_NR_PRIVATE_IRQS);
+}
+
 void vgic_v5_load(struct kvm_vcpu *vcpu)
 {
 	struct vgic_v5_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v5;
diff --git a/arch/arm64/kvm/vgic/vgic.c b/arch/arm64/kvm/vgic/vgic.c
index f3677535200ff..3b148d3d4875e 100644
--- a/arch/arm64/kvm/vgic/vgic.c
+++ b/arch/arm64/kvm/vgic/vgic.c
@@ -105,6 +105,18 @@ struct vgic_irq *vgic_get_vcpu_irq(struct kvm_vcpu *vcpu, u32 intid)
 	if (WARN_ON(!vcpu))
 		return NULL;
 
+	if (vgic_is_v5(vcpu->kvm)) {
+		u32 int_num, hwirq_id;
+
+		if (!__irq_is_ppi(KVM_DEV_TYPE_ARM_VGIC_V5, intid))
+			return NULL;
+
+		hwirq_id = FIELD_GET(GICV5_HWIRQ_ID, intid);
+		int_num = array_index_nospec(hwirq_id, VGIC_V5_NR_PRIVATE_IRQS);
+
+		return &vcpu->arch.vgic_cpu.private_irqs[int_num];
+	}
+
 	/* SGIs and PPIs */
 	if (intid < VGIC_NR_PRIVATE_IRQS) {
 		intid = array_index_nospec(intid, VGIC_NR_PRIVATE_IRQS);
@@ -841,8 +853,13 @@ static void vgic_prune_ap_list(struct kvm_vcpu *vcpu)
 		vgic_release_deleted_lpis(vcpu->kvm);
 }
 
-static inline void vgic_fold_lr_state(struct kvm_vcpu *vcpu)
+static void vgic_fold_state(struct kvm_vcpu *vcpu)
 {
+	if (vgic_is_v5(vcpu->kvm)) {
+		vgic_v5_fold_ppi_state(vcpu);
+		return;
+	}
+
 	if (!*host_data_ptr(last_lr_irq))
 		return;
 
@@ -1057,8 +1074,10 @@ void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu)
 	if (can_access_vgic_from_kernel())
 		vgic_save_state(vcpu);
 
-	vgic_fold_lr_state(vcpu);
-	vgic_prune_ap_list(vcpu);
+	vgic_fold_state(vcpu);
+
+	if (!vgic_is_v5(vcpu->kvm))
+		vgic_prune_ap_list(vcpu);
 }
 
 /* Sync interrupts that were deactivated through a DIR trap */
@@ -1091,6 +1110,17 @@ static inline void vgic_restore_state(struct kvm_vcpu *vcpu)
 		__vgic_v3_restore_state(&vcpu->arch.vgic_cpu.vgic_v3);
 }
 
+static void vgic_flush_state(struct kvm_vcpu *vcpu)
+{
+	if (vgic_is_v5(vcpu->kvm)) {
+		vgic_v5_flush_ppi_state(vcpu);
+		return;
+	}
+
+	scoped_guard(raw_spinlock, &vcpu->arch.vgic_cpu.ap_list_lock)
+		vgic_flush_lr_state(vcpu);
+}
+
 /* Flush our emulation state into the GIC hardware before entering the guest. */
 void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu)
 {
@@ -1127,13 +1157,12 @@ void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu)
 
 	DEBUG_SPINLOCK_BUG_ON(!irqs_disabled());
 
-	scoped_guard(raw_spinlock, &vcpu->arch.vgic_cpu.ap_list_lock)
-		vgic_flush_lr_state(vcpu);
+	vgic_flush_state(vcpu);
 
 	if (can_access_vgic_from_kernel())
 		vgic_restore_state(vcpu);
 
-	if (vgic_supports_direct_irqs(vcpu->kvm))
+	if (vgic_supports_direct_irqs(vcpu->kvm) && kvm_vgic_global_state.has_gicv4)
 		vgic_v4_commit(vcpu);
 }
 
diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h
index cc487a69d0389..ef4e3fb7159dd 100644
--- a/arch/arm64/kvm/vgic/vgic.h
+++ b/arch/arm64/kvm/vgic/vgic.h
@@ -364,6 +364,9 @@ void vgic_debug_init(struct kvm *kvm);
 void vgic_debug_destroy(struct kvm *kvm);
 
 int vgic_v5_probe(const struct gic_kvm_info *info);
+void vgic_v5_set_ppi_ops(struct vgic_irq *irq);
+void vgic_v5_flush_ppi_state(struct kvm_vcpu *vcpu);
+void vgic_v5_fold_ppi_state(struct kvm_vcpu *vcpu);
 void vgic_v5_load(struct kvm_vcpu *vcpu);
 void vgic_v5_put(struct kvm_vcpu *vcpu);
 void vgic_v5_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr);
@@ -432,15 +435,6 @@ void vgic_its_invalidate_all_caches(struct kvm *kvm);
 int vgic_its_inv_lpi(struct kvm *kvm, struct vgic_irq *irq);
 int vgic_its_invall(struct kvm_vcpu *vcpu);
 
-bool system_supports_direct_sgis(void);
-bool vgic_supports_direct_msis(struct kvm *kvm);
-bool vgic_supports_direct_sgis(struct kvm *kvm);
-
-static inline bool vgic_supports_direct_irqs(struct kvm *kvm)
-{
-	return vgic_supports_direct_msis(kvm) || vgic_supports_direct_sgis(kvm);
-}
-
 int vgic_v4_init(struct kvm *kvm);
 void vgic_v4_teardown(struct kvm *kvm);
 void vgic_v4_configure_vsgis(struct kvm *kvm);
@@ -481,6 +475,19 @@ static inline bool vgic_host_has_gicv5(void)
 	return kvm_vgic_global_state.type == VGIC_V5;
 }
 
+bool system_supports_direct_sgis(void);
+bool vgic_supports_direct_msis(struct kvm *kvm);
+bool vgic_supports_direct_sgis(struct kvm *kvm);
+
+static inline bool vgic_supports_direct_irqs(struct kvm *kvm)
+{
+	/* GICv5 always supports direct IRQs */
+	if (vgic_is_v5(kvm))
+		return true;
+
+	return vgic_supports_direct_msis(kvm) || vgic_supports_direct_sgis(kvm);
+}
+
 int vgic_its_debug_init(struct kvm_device *dev);
 void vgic_its_debug_destroy(struct kvm_device *dev);
 
-- 
2.34.1

Re: [PATCH v6 19/39] KVM: arm64: gic-v5: Implement PPI interrupt injection

[Marc Zyngier]

On Tue, 17 Mar 2026 11:44:55 +0000,
Sascha Bischoff <Sascha.Bischoff@arm.com> wrote:
> 
> This change introduces interrupt injection for PPIs for GICv5-based
> guests.
> 
> The lifecycle of PPIs is largely managed by the hardware for a GICv5
> system. The hypervisor injects pending state into the guest by using
> the ICH_PPI_PENDRx_EL2 registers. These are used by the hardware to
> pick a Highest Priority Pending Interrupt (HPPI) for the guest based
> on the enable state of each individual interrupt. The enable state and
> priority for each interrupt are provided by the guest itself (through
> writes to the PPI registers).
> 
> When Direct Virtual Interrupt (DVI) is set for a particular PPI, the
> hypervisor is even able to skip the injection of the pending state
> altogether - it all happens in hardware.
> 
> The result of the above is that no AP lists are required for GICv5,
> unlike for older GICs. Instead, for PPIs the ICH_PPI_* registers
> fulfil the same purpose for all 128 PPIs. Hence, as long as the
> ICH_PPI_* registers are populated prior to guest entry, and merged
> back into the KVM shadow state on exit, the PPI state is preserved,
> and interrupts can be injected.
> 
> When injecting the state of a PPI the state is merged into the
> PPI-specific vgic_irq structure. The PPIs are made pending via the
> ICH_PPI_PENDRx_EL2 registers, the value of which is generated from the
> vgic_irq structures for each PPI exposed on guest entry. The
> queue_irq_unlock() irq_op is required to kick the vCPU to ensure that
> it seems the new state. The result is that no AP lists are used for
> private interrupts on GICv5.
> 
> Prior to entering the guest, vgic_v5_flush_ppi_state() is called from
> kvm_vgic_flush_hwstate(). This generates the pending state to inject
> into the guest, and snapshots it (twice - an entry and an exit copy)
> in order to track any changes. These changes can come from a guest
> consuming an interrupt or from a guest making an Edge-triggered
> interrupt pending.
> 
> When returning from running a guest, the guest's PPI state is merged
> back into KVM's vgic_irq state in vgic_v5_merge_ppi_state() from
> kvm_vgic_sync_hwstate(). The Enable and Active state is synced back for
> all PPIs, and the pending state is synced back for Edge PPIs (Level is
> driven directly by the devices generating said levels). The incoming
> pending state from the guest is merged with KVM's shadow state to
> avoid losing any incoming interrupts.
> 
> Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
> ---
>  arch/arm64/kvm/vgic/vgic-v5.c | 143 ++++++++++++++++++++++++++++++++++
>  arch/arm64/kvm/vgic/vgic.c    |  41 ++++++++--
>  arch/arm64/kvm/vgic/vgic.h    |  25 +++---
>  3 files changed, 194 insertions(+), 15 deletions(-)
> 
> diff --git a/arch/arm64/kvm/vgic/vgic-v5.c b/arch/arm64/kvm/vgic/vgic-v5.c
> index 07f416fbc4bc8..e080fce61dc35 100644
> --- a/arch/arm64/kvm/vgic/vgic-v5.c
> +++ b/arch/arm64/kvm/vgic/vgic-v5.c
> @@ -122,6 +122,149 @@ int vgic_v5_finalize_ppi_state(struct kvm *kvm)
>  	return 0;
>  }
>  
> +/*
> + * For GICv5, the PPIs are mostly directly managed by the hardware. We (the
> + * hypervisor) handle the pending, active, enable state save/restore, but don't
> + * need the PPIs to be queued on a per-VCPU AP list. Therefore, sanity check the
> + * state, unlock, and return.
> + */
> +static bool vgic_v5_ppi_queue_irq_unlock(struct kvm *kvm, struct vgic_irq *irq,
> +					 unsigned long flags)
> +	__releases(&irq->irq_lock)
> +{
> +	struct kvm_vcpu *vcpu;
> +
> +	lockdep_assert_held(&irq->irq_lock);
> +
> +	if (WARN_ON_ONCE(!__irq_is_ppi(KVM_DEV_TYPE_ARM_VGIC_V5, irq->intid)))
> +		goto out_unlock_fail;
> +
> +	vcpu = irq->target_vcpu;
> +	if (WARN_ON_ONCE(!vcpu))
> +		goto out_unlock_fail;
> +
> +	raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
> +
> +	/* Directly kick the target VCPU to make sure it sees the IRQ */
> +	kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
> +	kvm_vcpu_kick(vcpu);
> +
> +	return true;
> +
> +out_unlock_fail:
> +	raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
> +
> +	return false;
> +}
> +
> +static struct irq_ops vgic_v5_ppi_irq_ops = {
> +	.queue_irq_unlock = vgic_v5_ppi_queue_irq_unlock,
> +};
> +
> +void vgic_v5_set_ppi_ops(struct vgic_irq *irq)
> +{
> +	if (WARN_ON(!irq))
> +		return;
> +
> +	guard(raw_spinlock_irqsave)(&irq->irq_lock);
> +
> +	if (!WARN_ON(irq->ops))
> +		irq->ops = &vgic_v5_ppi_irq_ops;
> +}

Why isn't this a call to kvm_vgic_set_irq_ops()? It feels very odd to
have two ways to do the same thing.

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.

Re: [PATCH v6 19/39] KVM: arm64: gic-v5: Implement PPI interrupt injection

[Sascha Bischoff]

On Tue, 2026-03-17 at 16:31 +0000, Marc Zyngier wrote:
> On Tue, 17 Mar 2026 11:44:55 +0000,
> Sascha Bischoff <Sascha.Bischoff@arm.com> wrote:
> > 
> > This change introduces interrupt injection for PPIs for GICv5-based
> > guests.
> > 
> > The lifecycle of PPIs is largely managed by the hardware for a
> > GICv5
> > system. The hypervisor injects pending state into the guest by
> > using
> > the ICH_PPI_PENDRx_EL2 registers. These are used by the hardware to
> > pick a Highest Priority Pending Interrupt (HPPI) for the guest
> > based
> > on the enable state of each individual interrupt. The enable state
> > and
> > priority for each interrupt are provided by the guest itself
> > (through
> > writes to the PPI registers).
> > 
> > When Direct Virtual Interrupt (DVI) is set for a particular PPI,
> > the
> > hypervisor is even able to skip the injection of the pending state
> > altogether - it all happens in hardware.
> > 
> > The result of the above is that no AP lists are required for GICv5,
> > unlike for older GICs. Instead, for PPIs the ICH_PPI_* registers
> > fulfil the same purpose for all 128 PPIs. Hence, as long as the
> > ICH_PPI_* registers are populated prior to guest entry, and merged
> > back into the KVM shadow state on exit, the PPI state is preserved,
> > and interrupts can be injected.
> > 
> > When injecting the state of a PPI the state is merged into the
> > PPI-specific vgic_irq structure. The PPIs are made pending via the
> > ICH_PPI_PENDRx_EL2 registers, the value of which is generated from
> > the
> > vgic_irq structures for each PPI exposed on guest entry. The
> > queue_irq_unlock() irq_op is required to kick the vCPU to ensure
> > that
> > it seems the new state. The result is that no AP lists are used for
> > private interrupts on GICv5.
> > 
> > Prior to entering the guest, vgic_v5_flush_ppi_state() is called
> > from
> > kvm_vgic_flush_hwstate(). This generates the pending state to
> > inject
> > into the guest, and snapshots it (twice - an entry and an exit
> > copy)
> > in order to track any changes. These changes can come from a guest
> > consuming an interrupt or from a guest making an Edge-triggered
> > interrupt pending.
> > 
> > When returning from running a guest, the guest's PPI state is
> > merged
> > back into KVM's vgic_irq state in vgic_v5_merge_ppi_state() from
> > kvm_vgic_sync_hwstate(). The Enable and Active state is synced back
> > for
> > all PPIs, and the pending state is synced back for Edge PPIs (Level
> > is
> > driven directly by the devices generating said levels). The
> > incoming
> > pending state from the guest is merged with KVM's shadow state to
> > avoid losing any incoming interrupts.
> > 
> > Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
> > Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
> > ---
> >  arch/arm64/kvm/vgic/vgic-v5.c | 143
> > ++++++++++++++++++++++++++++++++++
> >  arch/arm64/kvm/vgic/vgic.c    |  41 ++++++++--
> >  arch/arm64/kvm/vgic/vgic.h    |  25 +++---
> >  3 files changed, 194 insertions(+), 15 deletions(-)
> > 
> > diff --git a/arch/arm64/kvm/vgic/vgic-v5.c
> > b/arch/arm64/kvm/vgic/vgic-v5.c
> > index 07f416fbc4bc8..e080fce61dc35 100644
> > --- a/arch/arm64/kvm/vgic/vgic-v5.c
> > +++ b/arch/arm64/kvm/vgic/vgic-v5.c
> > @@ -122,6 +122,149 @@ int vgic_v5_finalize_ppi_state(struct kvm
> > *kvm)
> >  	return 0;
> >  }
> >  
> > +/*
> > + * For GICv5, the PPIs are mostly directly managed by the
> > hardware. We (the
> > + * hypervisor) handle the pending, active, enable state
> > save/restore, but don't
> > + * need the PPIs to be queued on a per-VCPU AP list. Therefore,
> > sanity check the
> > + * state, unlock, and return.
> > + */
> > +static bool vgic_v5_ppi_queue_irq_unlock(struct kvm *kvm, struct
> > vgic_irq *irq,
> > +					 unsigned long flags)
> > +	__releases(&irq->irq_lock)
> > +{
> > +	struct kvm_vcpu *vcpu;
> > +
> > +	lockdep_assert_held(&irq->irq_lock);
> > +
> > +	if (WARN_ON_ONCE(!__irq_is_ppi(KVM_DEV_TYPE_ARM_VGIC_V5,
> > irq->intid)))
> > +		goto out_unlock_fail;
> > +
> > +	vcpu = irq->target_vcpu;
> > +	if (WARN_ON_ONCE(!vcpu))
> > +		goto out_unlock_fail;
> > +
> > +	raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
> > +
> > +	/* Directly kick the target VCPU to make sure it sees the
> > IRQ */
> > +	kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
> > +	kvm_vcpu_kick(vcpu);
> > +
> > +	return true;
> > +
> > +out_unlock_fail:
> > +	raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
> > +
> > +	return false;
> > +}
> > +
> > +static struct irq_ops vgic_v5_ppi_irq_ops = {
> > +	.queue_irq_unlock = vgic_v5_ppi_queue_irq_unlock,
> > +};
> > +
> > +void vgic_v5_set_ppi_ops(struct vgic_irq *irq)
> > +{
> > +	if (WARN_ON(!irq))
> > +		return;
> > +
> > +	guard(raw_spinlock_irqsave)(&irq->irq_lock);
> > +
> > +	if (!WARN_ON(irq->ops))
> > +		irq->ops = &vgic_v5_ppi_irq_ops;
> > +}
> 
> Why isn't this a call to kvm_vgic_set_irq_ops()? It feels very odd to
> have two ways to do the same thing.

Absolutely no good reason not to do that. This needs to drop the taking
of the lock to avoid double locking, of course, but it makes sense.

I think this becomes:

diff --git a/arch/arm64/kvm/vgic/vgic-v5.c b/arch/arm64/kvm/vgic/vgic-
v5.c
index e080fce61dc35..a66e8bc1ca256 100644
--- a/arch/arm64/kvm/vgic/vgic-v5.c
+++ b/arch/arm64/kvm/vgic/vgic-v5.c
@@ -161,15 +161,9 @@ static struct irq_ops vgic_v5_ppi_irq_ops = {
        .queue_irq_unlock = vgic_v5_ppi_queue_irq_unlock,
 };
 
-void vgic_v5_set_ppi_ops(struct vgic_irq *irq)
+void vgic_v5_set_ppi_ops(struct kvm_vcpu *vcpu, u32 vintid)
 {
-       if (WARN_ON(!irq))
-               return;
-
-       guard(raw_spinlock_irqsave)(&irq->irq_lock);
-
-       if (!WARN_ON(irq->ops))
-               irq->ops = &vgic_v5_ppi_irq_ops;
+       kvm_vgic_set_irq_ops(vcpu, vintid, &vgic_v5_ppi_irq_ops);
 }
 
 /*
diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h
index ef4e3fb7159dd..d90af676d5d06 100644
--- a/arch/arm64/kvm/vgic/vgic.h
+++ b/arch/arm64/kvm/vgic/vgic.h
@@ -364,7 +364,7 @@ void vgic_debug_init(struct kvm *kvm);
 void vgic_debug_destroy(struct kvm *kvm);
 
 int vgic_v5_probe(const struct gic_kvm_info *info);
-void vgic_v5_set_ppi_ops(struct vgic_irq *irq);
+void vgic_v5_set_ppi_ops(struct kvm_vcpu *vcpu, u32 vintid);
 void vgic_v5_flush_ppi_state(struct kvm_vcpu *vcpu);
 void vgic_v5_fold_ppi_state(struct kvm_vcpu *vcpu);
 void vgic_v5_load(struct kvm_vcpu *vcpu);

Thanks,
Sascha

> 
> Thanks,
> 
> 	M.
> 

[PATCH v6 20/39] KVM: arm64: gic-v5: Init Private IRQs (PPIs) for GICv5

[Sascha Bischoff]

Initialise the private interrupts (PPIs, only) for GICv5. This means
that a GICv5-style intid is generated (which encodes the PPI type in
the top bits) instead of the 0-based index that is used for older
GICs.

Additionally, set all of the GICv5 PPIs to use Level for the handling
mode, with the exception of the SW_PPI which uses Edge. This matches
the architecturally-defined set in the GICv5 specification (the CTIIRQ
handling mode is IMPDEF, so Level has been picked for that).

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
---
 arch/arm64/kvm/vgic/vgic-init.c | 95 +++++++++++++++++++++++----------
 1 file changed, 66 insertions(+), 29 deletions(-)

diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c
index e1be9c5ada7b3..f8d7d5a895e79 100644
--- a/arch/arm64/kvm/vgic/vgic-init.c
+++ b/arch/arm64/kvm/vgic/vgic-init.c
@@ -250,9 +250,64 @@ int kvm_vgic_vcpu_nv_init(struct kvm_vcpu *vcpu)
 	return ret;
 }
 
+static void vgic_allocate_private_irq(struct kvm_vcpu *vcpu, int i, u32 type)
+{
+	struct vgic_irq *irq = &vcpu->arch.vgic_cpu.private_irqs[i];
+
+	INIT_LIST_HEAD(&irq->ap_list);
+	raw_spin_lock_init(&irq->irq_lock);
+	irq->vcpu = NULL;
+	irq->target_vcpu = vcpu;
+	refcount_set(&irq->refcount, 0);
+
+	irq->intid = i;
+	if (vgic_irq_is_sgi(i)) {
+		/* SGIs */
+		irq->enabled = 1;
+		irq->config = VGIC_CONFIG_EDGE;
+	} else {
+		/* PPIs */
+		irq->config = VGIC_CONFIG_LEVEL;
+	}
+
+	switch (type) {
+	case KVM_DEV_TYPE_ARM_VGIC_V3:
+		irq->group = 1;
+		irq->mpidr = kvm_vcpu_get_mpidr_aff(vcpu);
+		break;
+	case KVM_DEV_TYPE_ARM_VGIC_V2:
+		irq->group = 0;
+		irq->targets = BIT(vcpu->vcpu_id);
+		break;
+	}
+}
+
+static void vgic_v5_allocate_private_irq(struct kvm_vcpu *vcpu, int i, u32 type)
+{
+	struct vgic_irq *irq = &vcpu->arch.vgic_cpu.private_irqs[i];
+
+	INIT_LIST_HEAD(&irq->ap_list);
+	raw_spin_lock_init(&irq->irq_lock);
+	irq->vcpu = NULL;
+	irq->target_vcpu = vcpu;
+	refcount_set(&irq->refcount, 0);
+
+	irq->intid = vgic_v5_make_ppi(i);
+
+	/* The only Edge architected PPI is the SW_PPI */
+	if (i == GICV5_ARCH_PPI_SW_PPI)
+		irq->config = VGIC_CONFIG_EDGE;
+	else
+		irq->config = VGIC_CONFIG_LEVEL;
+
+	/* Register the GICv5-specific PPI ops */
+	vgic_v5_set_ppi_ops(irq);
+}
+
 static int vgic_allocate_private_irqs_locked(struct kvm_vcpu *vcpu, u32 type)
 {
 	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
+	u32 num_private_irqs;
 	int i;
 
 	lockdep_assert_held(&vcpu->kvm->arch.config_lock);
@@ -260,8 +315,13 @@ static int vgic_allocate_private_irqs_locked(struct kvm_vcpu *vcpu, u32 type)
 	if (vgic_cpu->private_irqs)
 		return 0;
 
+	if (vgic_is_v5(vcpu->kvm))
+		num_private_irqs = VGIC_V5_NR_PRIVATE_IRQS;
+	else
+		num_private_irqs = VGIC_NR_PRIVATE_IRQS;
+
 	vgic_cpu->private_irqs = kzalloc_objs(struct vgic_irq,
-					      VGIC_NR_PRIVATE_IRQS,
+					      num_private_irqs,
 					      GFP_KERNEL_ACCOUNT);
 
 	if (!vgic_cpu->private_irqs)
@@ -271,34 +331,11 @@ static int vgic_allocate_private_irqs_locked(struct kvm_vcpu *vcpu, u32 type)
 	 * Enable and configure all SGIs to be edge-triggered and
 	 * configure all PPIs as level-triggered.
 	 */
-	for (i = 0; i < VGIC_NR_PRIVATE_IRQS; i++) {
-		struct vgic_irq *irq = &vgic_cpu->private_irqs[i];
-
-		INIT_LIST_HEAD(&irq->ap_list);
-		raw_spin_lock_init(&irq->irq_lock);
-		irq->intid = i;
-		irq->vcpu = NULL;
-		irq->target_vcpu = vcpu;
-		refcount_set(&irq->refcount, 0);
-		if (vgic_irq_is_sgi(i)) {
-			/* SGIs */
-			irq->enabled = 1;
-			irq->config = VGIC_CONFIG_EDGE;
-		} else {
-			/* PPIs */
-			irq->config = VGIC_CONFIG_LEVEL;
-		}
-
-		switch (type) {
-		case KVM_DEV_TYPE_ARM_VGIC_V3:
-			irq->group = 1;
-			irq->mpidr = kvm_vcpu_get_mpidr_aff(vcpu);
-			break;
-		case KVM_DEV_TYPE_ARM_VGIC_V2:
-			irq->group = 0;
-			irq->targets = BIT(vcpu->vcpu_id);
-			break;
-		}
+	for (i = 0; i < num_private_irqs; i++) {
+		if (vgic_is_v5(vcpu->kvm))
+			vgic_v5_allocate_private_irq(vcpu, i, type);
+		else
+			vgic_allocate_private_irq(vcpu, i, type);
 	}
 
 	return 0;
-- 
2.34.1

Re: [PATCH v6 20/39] KVM: arm64: gic-v5: Init Private IRQs (PPIs) for GICv5

[Marc Zyngier]

On Tue, 17 Mar 2026 11:45:10 +0000,
Sascha Bischoff <Sascha.Bischoff@arm.com> wrote:
> 
> Initialise the private interrupts (PPIs, only) for GICv5. This means
> that a GICv5-style intid is generated (which encodes the PPI type in
> the top bits) instead of the 0-based index that is used for older
> GICs.
> 
> Additionally, set all of the GICv5 PPIs to use Level for the handling
> mode, with the exception of the SW_PPI which uses Edge. This matches
> the architecturally-defined set in the GICv5 specification (the CTIIRQ
> handling mode is IMPDEF, so Level has been picked for that).
> 
> Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
> ---
>  arch/arm64/kvm/vgic/vgic-init.c | 95 +++++++++++++++++++++++----------
>  1 file changed, 66 insertions(+), 29 deletions(-)
> 
> diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c
> index e1be9c5ada7b3..f8d7d5a895e79 100644
> --- a/arch/arm64/kvm/vgic/vgic-init.c
> +++ b/arch/arm64/kvm/vgic/vgic-init.c
> @@ -250,9 +250,64 @@ int kvm_vgic_vcpu_nv_init(struct kvm_vcpu *vcpu)
>  	return ret;
>  }
>  
> +static void vgic_allocate_private_irq(struct kvm_vcpu *vcpu, int i, u32 type)
> +{
> +	struct vgic_irq *irq = &vcpu->arch.vgic_cpu.private_irqs[i];
> +
> +	INIT_LIST_HEAD(&irq->ap_list);
> +	raw_spin_lock_init(&irq->irq_lock);
> +	irq->vcpu = NULL;
> +	irq->target_vcpu = vcpu;
> +	refcount_set(&irq->refcount, 0);
> +
> +	irq->intid = i;
> +	if (vgic_irq_is_sgi(i)) {
> +		/* SGIs */
> +		irq->enabled = 1;
> +		irq->config = VGIC_CONFIG_EDGE;
> +	} else {
> +		/* PPIs */
> +		irq->config = VGIC_CONFIG_LEVEL;
> +	}
> +
> +	switch (type) {
> +	case KVM_DEV_TYPE_ARM_VGIC_V3:
> +		irq->group = 1;
> +		irq->mpidr = kvm_vcpu_get_mpidr_aff(vcpu);
> +		break;
> +	case KVM_DEV_TYPE_ARM_VGIC_V2:
> +		irq->group = 0;
> +		irq->targets = BIT(vcpu->vcpu_id);
> +		break;
> +	}
> +}
> +
> +static void vgic_v5_allocate_private_irq(struct kvm_vcpu *vcpu, int i, u32 type)
> +{
> +	struct vgic_irq *irq = &vcpu->arch.vgic_cpu.private_irqs[i];
> +
> +	INIT_LIST_HEAD(&irq->ap_list);
> +	raw_spin_lock_init(&irq->irq_lock);
> +	irq->vcpu = NULL;
> +	irq->target_vcpu = vcpu;
> +	refcount_set(&irq->refcount, 0);
> +
> +	irq->intid = vgic_v5_make_ppi(i);
> +
> +	/* The only Edge architected PPI is the SW_PPI */
> +	if (i == GICV5_ARCH_PPI_SW_PPI)
> +		irq->config = VGIC_CONFIG_EDGE;
> +	else
> +		irq->config = VGIC_CONFIG_LEVEL;
> +
> +	/* Register the GICv5-specific PPI ops */
> +	vgic_v5_set_ppi_ops(irq);

I'd definitely expect this to use the generic accessor instead of
something v5-specific.

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.

Re: [PATCH v6 20/39] KVM: arm64: gic-v5: Init Private IRQs (PPIs) for GICv5

[Sascha Bischoff]

On Tue, 2026-03-17 at 16:42 +0000, Marc Zyngier wrote:
> On Tue, 17 Mar 2026 11:45:10 +0000,
> Sascha Bischoff <Sascha.Bischoff@arm.com> wrote:
> > 
> > Initialise the private interrupts (PPIs, only) for GICv5. This
> > means
> > that a GICv5-style intid is generated (which encodes the PPI type
> > in
> > the top bits) instead of the 0-based index that is used for older
> > GICs.
> > 
> > Additionally, set all of the GICv5 PPIs to use Level for the
> > handling
> > mode, with the exception of the SW_PPI which uses Edge. This
> > matches
> > the architecturally-defined set in the GICv5 specification (the
> > CTIIRQ
> > handling mode is IMPDEF, so Level has been picked for that).
> > 
> > Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
> > Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
> > ---
> >  arch/arm64/kvm/vgic/vgic-init.c | 95 +++++++++++++++++++++++------
> > ----
> >  1 file changed, 66 insertions(+), 29 deletions(-)
> > 
> > diff --git a/arch/arm64/kvm/vgic/vgic-init.c
> > b/arch/arm64/kvm/vgic/vgic-init.c
> > index e1be9c5ada7b3..f8d7d5a895e79 100644
> > --- a/arch/arm64/kvm/vgic/vgic-init.c
> > +++ b/arch/arm64/kvm/vgic/vgic-init.c
> > @@ -250,9 +250,64 @@ int kvm_vgic_vcpu_nv_init(struct kvm_vcpu
> > *vcpu)
> >  	return ret;
> >  }
> >  
> > +static void vgic_allocate_private_irq(struct kvm_vcpu *vcpu, int
> > i, u32 type)
> > +{
> > +	struct vgic_irq *irq = &vcpu-
> > >arch.vgic_cpu.private_irqs[i];
> > +
> > +	INIT_LIST_HEAD(&irq->ap_list);
> > +	raw_spin_lock_init(&irq->irq_lock);
> > +	irq->vcpu = NULL;
> > +	irq->target_vcpu = vcpu;
> > +	refcount_set(&irq->refcount, 0);
> > +
> > +	irq->intid = i;
> > +	if (vgic_irq_is_sgi(i)) {
> > +		/* SGIs */
> > +		irq->enabled = 1;
> > +		irq->config = VGIC_CONFIG_EDGE;
> > +	} else {
> > +		/* PPIs */
> > +		irq->config = VGIC_CONFIG_LEVEL;
> > +	}
> > +
> > +	switch (type) {
> > +	case KVM_DEV_TYPE_ARM_VGIC_V3:
> > +		irq->group = 1;
> > +		irq->mpidr = kvm_vcpu_get_mpidr_aff(vcpu);
> > +		break;
> > +	case KVM_DEV_TYPE_ARM_VGIC_V2:
> > +		irq->group = 0;
> > +		irq->targets = BIT(vcpu->vcpu_id);
> > +		break;
> > +	}
> > +}
> > +
> > +static void vgic_v5_allocate_private_irq(struct kvm_vcpu *vcpu,
> > int i, u32 type)
> > +{
> > +	struct vgic_irq *irq = &vcpu-
> > >arch.vgic_cpu.private_irqs[i];
> > +
> > +	INIT_LIST_HEAD(&irq->ap_list);
> > +	raw_spin_lock_init(&irq->irq_lock);
> > +	irq->vcpu = NULL;
> > +	irq->target_vcpu = vcpu;
> > +	refcount_set(&irq->refcount, 0);
> > +
> > +	irq->intid = vgic_v5_make_ppi(i);
> > +
> > +	/* The only Edge architected PPI is the SW_PPI */
> > +	if (i == GICV5_ARCH_PPI_SW_PPI)
> > +		irq->config = VGIC_CONFIG_EDGE;
> > +	else
> > +		irq->config = VGIC_CONFIG_LEVEL;
> > +
> > +	/* Register the GICv5-specific PPI ops */
> > +	vgic_v5_set_ppi_ops(irq);
> 
> I'd definitely expect this to use the generic accessor instead of
> something v5-specific.

I think it is cleaner to use a helper here, as otherwise we need to
expose the instance of struct irq_ops outside of the vgic-v5 code.
We're already handling a special case for vgic-v5 here.

Given my response to the previous patch, this code would be changed
with:

diff --git a/arch/arm64/kvm/vgic/vgic-init.c
b/arch/arm64/kvm/vgic/vgic-init.c
index f8d7d5a895e79..e0366e8c144d5 100644
--- a/arch/arm64/kvm/vgic/vgic-init.c
+++ b/arch/arm64/kvm/vgic/vgic-init.c
@@ -285,6 +285,7 @@ static void vgic_allocate_private_irq(struct
kvm_vcpu *vcpu, int i, u32 type)
 static void vgic_v5_allocate_private_irq(struct kvm_vcpu *vcpu, int i,
u32 type)
 {
        struct vgic_irq *irq = &vcpu->arch.vgic_cpu.private_irqs[i];
+       u32 intid = vgic_v5_make_ppi(i);
 
        INIT_LIST_HEAD(&irq->ap_list);
        raw_spin_lock_init(&irq->irq_lock);
@@ -292,7 +293,7 @@ static void vgic_v5_allocate_private_irq(struct
kvm_vcpu *vcpu, int i, u32 type)
        irq->target_vcpu = vcpu;
        refcount_set(&irq->refcount, 0);
 
-       irq->intid = vgic_v5_make_ppi(i);
+       irq->intid = intid;
 
        /* The only Edge architected PPI is the SW_PPI */
        if (i == GICV5_ARCH_PPI_SW_PPI)
@@ -301,7 +302,7 @@ static void vgic_v5_allocate_private_irq(struct
kvm_vcpu *vcpu, int i, u32 type)
                irq->config = VGIC_CONFIG_LEVEL;
 
        /* Register the GICv5-specific PPI ops */
-       vgic_v5_set_ppi_ops(irq);
+       vgic_v5_set_ppi_ops(vcpu, intid);
 }
 
 static int vgic_allocate_private_irqs_locked(struct kvm_vcpu *vcpu,
u32 type)

Thanks,
Sascha

> 
> Thanks,
> 
> 	M.
> 

[PATCH v6 21/39] KVM: arm64: gic-v5: Clear TWI if single task running

[Sascha Bischoff]

Handle GICv5 in kvm_vcpu_should_clear_twi(). Clear TWI if there is a
single task running, and enable it otherwise. This is a sane default
for GICv5 given the current level of support.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
---
 arch/arm64/kvm/arm.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 5bbc1adb705e2..f68c4036afebd 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -613,6 +613,9 @@ static bool kvm_vcpu_should_clear_twi(struct kvm_vcpu *vcpu)
 	if (unlikely(kvm_wfi_trap_policy != KVM_WFX_NOTRAP_SINGLE_TASK))
 		return kvm_wfi_trap_policy == KVM_WFX_NOTRAP;
 
+	if (vgic_is_v5(vcpu->kvm))
+		return single_task_running();
+
 	return single_task_running() &&
 	       vcpu->kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3 &&
 	       (atomic_read(&vcpu->arch.vgic_cpu.vgic_v3.its_vpe.vlpi_count) ||
-- 
2.34.1

[PATCH v6 22/39] KVM: arm64: gic-v5: Check for pending PPIs

[Sascha Bischoff]

This change allows KVM to check for pending PPI interrupts. This has
two main components:

First of all, the effective priority mask is calculated.  This is a
combination of the priority mask in the VPEs ICC_PCR_EL1.PRIORITY and
the currently running priority as determined from the VPE's
ICH_APR_EL1. If an interrupt's priority is greater than or equal to
the effective priority mask, it can be signalled. Otherwise, it
cannot.

Secondly, any Enabled and Pending PPIs must be checked against this
compound priority mask. The reqires the PPI priorities to by synced
back to the KVM shadow state on WFI entry - this is skipped in general
operation as it isn't required and is rather expensive. If any Enabled
and Pending PPIs are of sufficient priority to be signalled, then
there are pending PPIs. Else, there are not. This ensures that a VPE
is not woken when it cannot actually process the pending interrupts.

As the PPI priorities are not synced back to the KVM shadow state on
every guest exit, they must by synced prior to checking if there are
pending interrupts for the guest. The sync itself happens in
vgic_v5_put() if, and only if, the vcpu is entering WFI as this is the
only case where it is not planned to run the vcpu thread again. If the
vcpu enters WFI, the vcpu thread will be descheduled and won't be
rescheduled again until it has a pending interrupt, which is checked
from kvm_arch_vcpu_runnable().

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
---
 arch/arm64/kvm/vgic/vgic-v5.c | 101 ++++++++++++++++++++++++++++++++++
 arch/arm64/kvm/vgic/vgic.c    |   3 +
 arch/arm64/kvm/vgic/vgic.h    |   1 +
 3 files changed, 105 insertions(+)

diff --git a/arch/arm64/kvm/vgic/vgic-v5.c b/arch/arm64/kvm/vgic/vgic-v5.c
index e080fce61dc35..14dba634f79b4 100644
--- a/arch/arm64/kvm/vgic/vgic-v5.c
+++ b/arch/arm64/kvm/vgic/vgic-v5.c
@@ -122,6 +122,29 @@ int vgic_v5_finalize_ppi_state(struct kvm *kvm)
 	return 0;
 }
 
+static u32 vgic_v5_get_effective_priority_mask(struct kvm_vcpu *vcpu)
+{
+	struct vgic_v5_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v5;
+	u32 highest_ap, priority_mask;
+
+	/*
+	 * Counting the number of trailing zeros gives the current active
+	 * priority. Explicitly use the 32-bit version here as we have 32
+	 * priorities. 32 then means that there are no active priorities.
+	 */
+	highest_ap = cpu_if->vgic_apr ? __builtin_ctz(cpu_if->vgic_apr) : 32;
+
+	/*
+	 * An interrupt is of sufficient priority if it is equal to or
+	 * greater than the priority mask. Add 1 to the priority mask
+	 * (i.e., lower priority) to match the APR logic before taking
+	 * the min. This gives us the lowest priority that is masked.
+	 */
+	priority_mask = FIELD_GET(FEAT_GCIE_ICH_VMCR_EL2_VPMR, cpu_if->vgic_vmcr);
+
+	return min(highest_ap, priority_mask + 1);
+}
+
 /*
  * For GICv5, the PPIs are mostly directly managed by the hardware. We (the
  * hypervisor) handle the pending, active, enable state save/restore, but don't
@@ -172,6 +195,80 @@ void vgic_v5_set_ppi_ops(struct vgic_irq *irq)
 		irq->ops = &vgic_v5_ppi_irq_ops;
 }
 
+/*
+ * Sync back the PPI priorities to the vgic_irq shadow state for any interrupts
+ * exposed to the guest (skipping all others).
+ */
+static void vgic_v5_sync_ppi_priorities(struct kvm_vcpu *vcpu)
+{
+	struct vgic_v5_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v5;
+	u64 priorityr;
+	int i;
+
+	/*
+	 * We have up to 16 PPI Priority regs, but only have a few interrupts
+	 * that the guest is allowed to use. Limit our sync of PPI priorities to
+	 * those actually exposed to the guest by first iterating over the mask
+	 * of exposed PPIs.
+	 */
+	for_each_set_bit(i, vcpu->kvm->arch.vgic.gicv5_vm.vgic_ppi_mask, VGIC_V5_NR_PRIVATE_IRQS) {
+		u32 intid = vgic_v5_make_ppi(i);
+		struct vgic_irq *irq;
+		int pri_idx, pri_reg;
+		u8 priority;
+
+		/*
+		 * Determine which priority register and the field within it to
+		 * extract.
+		 */
+		pri_reg = i / 8;
+		pri_idx = i % 8;
+
+		priorityr = cpu_if->vgic_ppi_priorityr[pri_reg];
+		priority = (priorityr >> (pri_idx * 8)) & GENMASK(4, 0);
+
+		irq = vgic_get_vcpu_irq(vcpu, intid);
+
+		scoped_guard(raw_spinlock_irqsave, &irq->irq_lock)
+			irq->priority = priority;
+
+		vgic_put_irq(vcpu->kvm, irq);
+	}
+}
+
+bool vgic_v5_has_pending_ppi(struct kvm_vcpu *vcpu)
+{
+	unsigned int priority_mask;
+	int i;
+
+	priority_mask = vgic_v5_get_effective_priority_mask(vcpu);
+
+	/* If the combined priority mask is 0, nothing can be signalled! */
+	if (!priority_mask)
+		return false;
+
+	for_each_set_bit(i, vcpu->kvm->arch.vgic.gicv5_vm.vgic_ppi_mask, VGIC_V5_NR_PRIVATE_IRQS) {
+		u32 intid = vgic_v5_make_ppi(i);
+		bool has_pending = false;
+		struct vgic_irq *irq;
+
+		irq = vgic_get_vcpu_irq(vcpu, intid);
+
+		scoped_guard(raw_spinlock_irqsave, &irq->irq_lock) {
+			if (irq->enabled && irq_is_pending(irq) &&
+			    irq->priority <= priority_mask)
+				has_pending = true;
+		}
+
+		vgic_put_irq(vcpu->kvm, irq);
+
+		if (has_pending)
+			return true;
+	}
+
+	return false;
+}
+
 /*
  * Detect any PPIs state changes, and propagate the state with KVM's
  * shadow structures.
@@ -299,6 +396,10 @@ void vgic_v5_put(struct kvm_vcpu *vcpu)
 	kvm_call_hyp(__vgic_v5_save_apr, cpu_if);
 
 	cpu_if->gicv5_vpe.resident = false;
+
+	/* The shadow priority is only updated on entering WFI */
+	if (vcpu_get_flag(vcpu, IN_WFI))
+		vgic_v5_sync_ppi_priorities(vcpu);
 }
 
 void vgic_v5_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcrp)
diff --git a/arch/arm64/kvm/vgic/vgic.c b/arch/arm64/kvm/vgic/vgic.c
index 3b148d3d4875e..d448205d80617 100644
--- a/arch/arm64/kvm/vgic/vgic.c
+++ b/arch/arm64/kvm/vgic/vgic.c
@@ -1230,6 +1230,9 @@ int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu)
 	unsigned long flags;
 	struct vgic_vmcr vmcr;
 
+	if (vgic_is_v5(vcpu->kvm))
+		return vgic_v5_has_pending_ppi(vcpu);
+
 	if (!vcpu->kvm->arch.vgic.enabled)
 		return false;
 
diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h
index ef4e3fb7159dd..3a9e610eefb00 100644
--- a/arch/arm64/kvm/vgic/vgic.h
+++ b/arch/arm64/kvm/vgic/vgic.h
@@ -365,6 +365,7 @@ void vgic_debug_destroy(struct kvm *kvm);
 
 int vgic_v5_probe(const struct gic_kvm_info *info);
 void vgic_v5_set_ppi_ops(struct vgic_irq *irq);
+bool vgic_v5_has_pending_ppi(struct kvm_vcpu *vcpu);
 void vgic_v5_flush_ppi_state(struct kvm_vcpu *vcpu);
 void vgic_v5_fold_ppi_state(struct kvm_vcpu *vcpu);
 void vgic_v5_load(struct kvm_vcpu *vcpu);
-- 
2.34.1

Re: [PATCH v6 22/39] KVM: arm64: gic-v5: Check for pending PPIs

[Marc Zyngier]

On Tue, 17 Mar 2026 11:45:41 +0000,
Sascha Bischoff <Sascha.Bischoff@arm.com> wrote:
> 
> This change allows KVM to check for pending PPI interrupts. This has
> two main components:
> 
> First of all, the effective priority mask is calculated.  This is a
> combination of the priority mask in the VPEs ICC_PCR_EL1.PRIORITY and
> the currently running priority as determined from the VPE's
> ICH_APR_EL1. If an interrupt's priority is greater than or equal to
> the effective priority mask, it can be signalled. Otherwise, it
> cannot.
> 
> Secondly, any Enabled and Pending PPIs must be checked against this
> compound priority mask. The reqires the PPI priorities to by synced
> back to the KVM shadow state on WFI entry - this is skipped in general
> operation as it isn't required and is rather expensive. If any Enabled
> and Pending PPIs are of sufficient priority to be signalled, then
> there are pending PPIs. Else, there are not. This ensures that a VPE
> is not woken when it cannot actually process the pending interrupts.
> 
> As the PPI priorities are not synced back to the KVM shadow state on
> every guest exit, they must by synced prior to checking if there are
> pending interrupts for the guest. The sync itself happens in
> vgic_v5_put() if, and only if, the vcpu is entering WFI as this is the
> only case where it is not planned to run the vcpu thread again. If the
> vcpu enters WFI, the vcpu thread will be descheduled and won't be
> rescheduled again until it has a pending interrupt, which is checked
> from kvm_arch_vcpu_runnable().
> 
> Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
> Reviewed-by: Joey Gouly <joey.gouly@arm.com>
> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
> ---
>  arch/arm64/kvm/vgic/vgic-v5.c | 101 ++++++++++++++++++++++++++++++++++
>  arch/arm64/kvm/vgic/vgic.c    |   3 +
>  arch/arm64/kvm/vgic/vgic.h    |   1 +
>  3 files changed, 105 insertions(+)
> 
> diff --git a/arch/arm64/kvm/vgic/vgic-v5.c b/arch/arm64/kvm/vgic/vgic-v5.c
> index e080fce61dc35..14dba634f79b4 100644
> --- a/arch/arm64/kvm/vgic/vgic-v5.c
> +++ b/arch/arm64/kvm/vgic/vgic-v5.c
> @@ -122,6 +122,29 @@ int vgic_v5_finalize_ppi_state(struct kvm *kvm)
>  	return 0;
>  }
>  
> +static u32 vgic_v5_get_effective_priority_mask(struct kvm_vcpu *vcpu)
> +{
> +	struct vgic_v5_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v5;
> +	u32 highest_ap, priority_mask;
> +
> +	/*
> +	 * Counting the number of trailing zeros gives the current active
> +	 * priority. Explicitly use the 32-bit version here as we have 32
> +	 * priorities. 32 then means that there are no active priorities.
> +	 */
> +	highest_ap = cpu_if->vgic_apr ? __builtin_ctz(cpu_if->vgic_apr) : 32;
> +
> +	/*
> +	 * An interrupt is of sufficient priority if it is equal to or
> +	 * greater than the priority mask. Add 1 to the priority mask
> +	 * (i.e., lower priority) to match the APR logic before taking
> +	 * the min. This gives us the lowest priority that is masked.
> +	 */
> +	priority_mask = FIELD_GET(FEAT_GCIE_ICH_VMCR_EL2_VPMR, cpu_if->vgic_vmcr);
> +
> +	return min(highest_ap, priority_mask + 1);
> +}
> +
>  /*
>   * For GICv5, the PPIs are mostly directly managed by the hardware. We (the
>   * hypervisor) handle the pending, active, enable state save/restore, but don't
> @@ -172,6 +195,80 @@ void vgic_v5_set_ppi_ops(struct vgic_irq *irq)
>  		irq->ops = &vgic_v5_ppi_irq_ops;
>  }
>  
> +/*
> + * Sync back the PPI priorities to the vgic_irq shadow state for any interrupts
> + * exposed to the guest (skipping all others).
> + */
> +static void vgic_v5_sync_ppi_priorities(struct kvm_vcpu *vcpu)
> +{
> +	struct vgic_v5_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v5;
> +	u64 priorityr;
> +	int i;
> +
> +	/*
> +	 * We have up to 16 PPI Priority regs, but only have a few interrupts
> +	 * that the guest is allowed to use. Limit our sync of PPI priorities to
> +	 * those actually exposed to the guest by first iterating over the mask
> +	 * of exposed PPIs.
> +	 */
> +	for_each_set_bit(i, vcpu->kvm->arch.vgic.gicv5_vm.vgic_ppi_mask, VGIC_V5_NR_PRIVATE_IRQS) {
> +		u32 intid = vgic_v5_make_ppi(i);
> +		struct vgic_irq *irq;
> +		int pri_idx, pri_reg;
> +		u8 priority;
> +
> +		/*
> +		 * Determine which priority register and the field within it to
> +		 * extract.
> +		 */
> +		pri_reg = i / 8;
> +		pri_idx = i % 8;
> +
> +		priorityr = cpu_if->vgic_ppi_priorityr[pri_reg];
> +		priority = (priorityr >> (pri_idx * 8)) & GENMASK(4, 0);

It should be able to write this as:

		pri_bit = pri_idx * 8;
		priority = field_get(GENMASK(pri_bit + 4, pri_bit), priorityr);

which while more verbose, clearly shows that you are extracting a
field from the register.

> +
> +		irq = vgic_get_vcpu_irq(vcpu, intid);
> +
> +		scoped_guard(raw_spinlock_irqsave, &irq->irq_lock)
> +			irq->priority = priority;
> +
> +		vgic_put_irq(vcpu->kvm, irq);
> +	}
> +}
> +
> +bool vgic_v5_has_pending_ppi(struct kvm_vcpu *vcpu)
> +{
> +	unsigned int priority_mask;
> +	int i;
> +
> +	priority_mask = vgic_v5_get_effective_priority_mask(vcpu);
> +
> +	/* If the combined priority mask is 0, nothing can be signalled! */
> +	if (!priority_mask)
> +		return false;

The other case when nothing can be signalled is when ICH_VMCR_EL2.En
== 0, meaning that the guest hasn't enabled interrupts at all.

This should be taken into account, or a trapping WFI is going to turn
into a nice CPU hog.

> +
> +	for_each_set_bit(i, vcpu->kvm->arch.vgic.gicv5_vm.vgic_ppi_mask, VGIC_V5_NR_PRIVATE_IRQS) {
> +		u32 intid = vgic_v5_make_ppi(i);
> +		bool has_pending = false;
> +		struct vgic_irq *irq;
> +
> +		irq = vgic_get_vcpu_irq(vcpu, intid);
> +
> +		scoped_guard(raw_spinlock_irqsave, &irq->irq_lock) {
> +			if (irq->enabled && irq_is_pending(irq) &&
> +			    irq->priority <= priority_mask)
> +				has_pending = true;
> +		}

nit:
		scoped_guard(raw_spinlock_irqsave, &irq->irq_lock)
			has_pending = (irq->enabled && irq_is_pending(irq) &&
				       irq->priority <= priority_mask);

> +
> +		vgic_put_irq(vcpu->kvm, irq);
> +
> +		if (has_pending)
> +			return true;
> +	}
> +
> +	return false;
> +}
> +
>  /*
>   * Detect any PPIs state changes, and propagate the state with KVM's
>   * shadow structures.
> @@ -299,6 +396,10 @@ void vgic_v5_put(struct kvm_vcpu *vcpu)
>  	kvm_call_hyp(__vgic_v5_save_apr, cpu_if);
>  
>  	cpu_if->gicv5_vpe.resident = false;
> +
> +	/* The shadow priority is only updated on entering WFI */
> +	if (vcpu_get_flag(vcpu, IN_WFI))
> +		vgic_v5_sync_ppi_priorities(vcpu);
>  }
>  
>  void vgic_v5_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcrp)
> diff --git a/arch/arm64/kvm/vgic/vgic.c b/arch/arm64/kvm/vgic/vgic.c
> index 3b148d3d4875e..d448205d80617 100644
> --- a/arch/arm64/kvm/vgic/vgic.c
> +++ b/arch/arm64/kvm/vgic/vgic.c
> @@ -1230,6 +1230,9 @@ int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu)
>  	unsigned long flags;
>  	struct vgic_vmcr vmcr;
>  
> +	if (vgic_is_v5(vcpu->kvm))
> +		return vgic_v5_has_pending_ppi(vcpu);
> +
>  	if (!vcpu->kvm->arch.vgic.enabled)
>  		return false;
>  
> diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h
> index ef4e3fb7159dd..3a9e610eefb00 100644
> --- a/arch/arm64/kvm/vgic/vgic.h
> +++ b/arch/arm64/kvm/vgic/vgic.h
> @@ -365,6 +365,7 @@ void vgic_debug_destroy(struct kvm *kvm);
>  
>  int vgic_v5_probe(const struct gic_kvm_info *info);
>  void vgic_v5_set_ppi_ops(struct vgic_irq *irq);
> +bool vgic_v5_has_pending_ppi(struct kvm_vcpu *vcpu);
>  void vgic_v5_flush_ppi_state(struct kvm_vcpu *vcpu);
>  void vgic_v5_fold_ppi_state(struct kvm_vcpu *vcpu);
>  void vgic_v5_load(struct kvm_vcpu *vcpu);

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.

Re: [PATCH v6 22/39] KVM: arm64: gic-v5: Check for pending PPIs

[Sascha Bischoff]

On Tue, 2026-03-17 at 17:08 +0000, Marc Zyngier wrote:
> On Tue, 17 Mar 2026 11:45:41 +0000,
> Sascha Bischoff <Sascha.Bischoff@arm.com> wrote:
> > 
> > This change allows KVM to check for pending PPI interrupts. This
> > has
> > two main components:
> > 
> > First of all, the effective priority mask is calculated.  This is a
> > combination of the priority mask in the VPEs ICC_PCR_EL1.PRIORITY
> > and
> > the currently running priority as determined from the VPE's
> > ICH_APR_EL1. If an interrupt's priority is greater than or equal to
> > the effective priority mask, it can be signalled. Otherwise, it
> > cannot.
> > 
> > Secondly, any Enabled and Pending PPIs must be checked against this
> > compound priority mask. The reqires the PPI priorities to by synced
> > back to the KVM shadow state on WFI entry - this is skipped in
> > general
> > operation as it isn't required and is rather expensive. If any
> > Enabled
> > and Pending PPIs are of sufficient priority to be signalled, then
> > there are pending PPIs. Else, there are not. This ensures that a
> > VPE
> > is not woken when it cannot actually process the pending
> > interrupts.
> > 
> > As the PPI priorities are not synced back to the KVM shadow state
> > on
> > every guest exit, they must by synced prior to checking if there
> > are
> > pending interrupts for the guest. The sync itself happens in
> > vgic_v5_put() if, and only if, the vcpu is entering WFI as this is
> > the
> > only case where it is not planned to run the vcpu thread again. If
> > the
> > vcpu enters WFI, the vcpu thread will be descheduled and won't be
> > rescheduled again until it has a pending interrupt, which is
> > checked
> > from kvm_arch_vcpu_runnable().
> > 
> > Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
> > Reviewed-by: Joey Gouly <joey.gouly@arm.com>
> > Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
> > ---
> >  arch/arm64/kvm/vgic/vgic-v5.c | 101
> > ++++++++++++++++++++++++++++++++++
> >  arch/arm64/kvm/vgic/vgic.c    |   3 +
> >  arch/arm64/kvm/vgic/vgic.h    |   1 +
> >  3 files changed, 105 insertions(+)
> > 
> > diff --git a/arch/arm64/kvm/vgic/vgic-v5.c
> > b/arch/arm64/kvm/vgic/vgic-v5.c
> > index e080fce61dc35..14dba634f79b4 100644
> > --- a/arch/arm64/kvm/vgic/vgic-v5.c
> > +++ b/arch/arm64/kvm/vgic/vgic-v5.c
> > @@ -122,6 +122,29 @@ int vgic_v5_finalize_ppi_state(struct kvm
> > *kvm)
> >  	return 0;
> >  }
> >  
> > +static u32 vgic_v5_get_effective_priority_mask(struct kvm_vcpu
> > *vcpu)
> > +{
> > +	struct vgic_v5_cpu_if *cpu_if = &vcpu-
> > >arch.vgic_cpu.vgic_v5;
> > +	u32 highest_ap, priority_mask;
> > +
> > +	/*
> > +	 * Counting the number of trailing zeros gives the current
> > active
> > +	 * priority. Explicitly use the 32-bit version here as we
> > have 32
> > +	 * priorities. 32 then means that there are no active
> > priorities.
> > +	 */
> > +	highest_ap = cpu_if->vgic_apr ? __builtin_ctz(cpu_if-
> > >vgic_apr) : 32;
> > +
> > +	/*
> > +	 * An interrupt is of sufficient priority if it is equal
> > to or
> > +	 * greater than the priority mask. Add 1 to the priority
> > mask
> > +	 * (i.e., lower priority) to match the APR logic before
> > taking
> > +	 * the min. This gives us the lowest priority that is
> > masked.
> > +	 */
> > +	priority_mask = FIELD_GET(FEAT_GCIE_ICH_VMCR_EL2_VPMR,
> > cpu_if->vgic_vmcr);
> > +
> > +	return min(highest_ap, priority_mask + 1);
> > +}
> > +
> >  /*
> >   * For GICv5, the PPIs are mostly directly managed by the
> > hardware. We (the
> >   * hypervisor) handle the pending, active, enable state
> > save/restore, but don't
> > @@ -172,6 +195,80 @@ void vgic_v5_set_ppi_ops(struct vgic_irq *irq)
> >  		irq->ops = &vgic_v5_ppi_irq_ops;
> >  }
> >  
> > +/*
> > + * Sync back the PPI priorities to the vgic_irq shadow state for
> > any interrupts
> > + * exposed to the guest (skipping all others).
> > + */
> > +static void vgic_v5_sync_ppi_priorities(struct kvm_vcpu *vcpu)
> > +{
> > +	struct vgic_v5_cpu_if *cpu_if = &vcpu-
> > >arch.vgic_cpu.vgic_v5;
> > +	u64 priorityr;
> > +	int i;
> > +
> > +	/*
> > +	 * We have up to 16 PPI Priority regs, but only have a few
> > interrupts
> > +	 * that the guest is allowed to use. Limit our sync of PPI
> > priorities to
> > +	 * those actually exposed to the guest by first iterating
> > over the mask
> > +	 * of exposed PPIs.
> > +	 */
> > +	for_each_set_bit(i, vcpu->kvm-
> > >arch.vgic.gicv5_vm.vgic_ppi_mask, VGIC_V5_NR_PRIVATE_IRQS) {
> > +		u32 intid = vgic_v5_make_ppi(i);
> > +		struct vgic_irq *irq;
> > +		int pri_idx, pri_reg;
> > +		u8 priority;
> > +
> > +		/*
> > +		 * Determine which priority register and the field
> > within it to
> > +		 * extract.
> > +		 */
> > +		pri_reg = i / 8;
> > +		pri_idx = i % 8;
> > +
> > +		priorityr = cpu_if->vgic_ppi_priorityr[pri_reg];
> > +		priority = (priorityr >> (pri_idx * 8)) &
> > GENMASK(4, 0);
> 
> It should be able to write this as:
> 
> 		pri_bit = pri_idx * 8;
> 		priority = field_get(GENMASK(pri_bit + 4, pri_bit),
> priorityr);
> 
> which while more verbose, clearly shows that you are extracting a
> field from the register.

Yeah, that's definitely better. Thanks.

> 
> > +
> > +		irq = vgic_get_vcpu_irq(vcpu, intid);
> > +
> > +		scoped_guard(raw_spinlock_irqsave, &irq->irq_lock)
> > +			irq->priority = priority;
> > +
> > +		vgic_put_irq(vcpu->kvm, irq);
> > +	}
> > +}
> > +
> > +bool vgic_v5_has_pending_ppi(struct kvm_vcpu *vcpu)
> > +{
> > +	unsigned int priority_mask;
> > +	int i;
> > +
> > +	priority_mask = vgic_v5_get_effective_priority_mask(vcpu);
> > +
> > +	/* If the combined priority mask is 0, nothing can be
> > signalled! */
> > +	if (!priority_mask)
> > +		return false;
> 
> The other case when nothing can be signalled is when ICH_VMCR_EL2.En
> == 0, meaning that the guest hasn't enabled interrupts at all.
> 
> This should be taken into account, or a trapping WFI is going to turn
> into a nice CPU hog.

Very valid point.

There are two options for this. The ICH_VMCR_EL2 contains the En bit
(which is an alias of ICH_CR0_EL1.EN, i.e., is set/cleared when the
guest enables/disables interrupt delivery for a vcpu).

The first would be to explicitly check this bit when determining if
there are pending PPIs for a vcpu. However, this would need to be
checked in multiple places as the code evolves. One of these cases
would be when requesting a VPE Doorbell.

For both PPIs and VPE Doorbells, one needs to figure out the threshold
for an interrupt signalling. Therefore, I think it makes more sense to
roll this into the calculation of the priority mask. Effectively, if a
vcpu has not opted into interrupt delivery, the effective running
priority is the highest priority and nothing can signal. This is the
second option.

I am proposing this change:

diff --git a/arch/arm64/kvm/vgic/vgic-v5.c b/arch/arm64/kvm/vgic/vgic-v5.c
index 22230e6eaa8bb..450960b792331 100644
--- a/arch/arm64/kvm/vgic/vgic-v5.c
+++ b/arch/arm64/kvm/vgic/vgic-v5.c
@@ -127,6 +127,14 @@ static u32 vgic_v5_get_effective_priority_mask(struct kvm_vcpu *vcpu)
        struct vgic_v5_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v5;
        u32 highest_ap, priority_mask;
 
+       /*
+        * If the guest's CPU has not opted to receive interrupts, then the
+        * effective running priority is the highest priority. Just return 0
+        * (the highest priority).
+        */
+       if (!FIELD_GET(FEAT_GCIE_ICH_VMCR_EL2_EN, cpu_if->vgic_vmcr))
+               return 0;
+
        /*
         * Counting the number of trailing zeros gives the current active
         * priority. Explicitly use the 32-bit version here as we have 32
@@ -237,7 +245,12 @@ bool vgic_v5_has_pending_ppi(struct kvm_vcpu *vcpu)
 
        priority_mask = vgic_v5_get_effective_priority_mask(vcpu);
 
-       /* If the combined priority mask is 0, nothing can be signalled! */
+       /*
+        * If the combined priority mask is 0, nothing can be signalled! In the
+        * case where the guest has disabled interrupt delivery for the vcpu
+        * (via ICV_CR0_EL1.EN->ICH_VMCR_EL2.EN), we calculate the priority mask
+        * as 0 too (the highest possible priority).
+        */
        if (!priority_mask)
                return false;


> 
> > +
> > +	for_each_set_bit(i, vcpu->kvm-
> > >arch.vgic.gicv5_vm.vgic_ppi_mask, VGIC_V5_NR_PRIVATE_IRQS) {
> > +		u32 intid = vgic_v5_make_ppi(i);
> > +		bool has_pending = false;
> > +		struct vgic_irq *irq;
> > +
> > +		irq = vgic_get_vcpu_irq(vcpu, intid);
> > +
> > +		scoped_guard(raw_spinlock_irqsave, &irq->irq_lock)
> > {
> > +			if (irq->enabled && irq_is_pending(irq) &&
> > +			    irq->priority <= priority_mask)
> > +				has_pending = true;
> > +		}
> 
> nit:
> 		scoped_guard(raw_spinlock_irqsave, &irq->irq_lock)
> 			has_pending = (irq->enabled &&
> irq_is_pending(irq) &&
> 				       irq->priority <=
> priority_mask);

Done

Thanks,
Sascha

> 
> > +
> > +		vgic_put_irq(vcpu->kvm, irq);
> > +
> > +		if (has_pending)
> > +			return true;
> > +	}
> > +
> > +	return false;
> > +}
> > +
> >  /*
> >   * Detect any PPIs state changes, and propagate the state with
> > KVM's
> >   * shadow structures.
> > @@ -299,6 +396,10 @@ void vgic_v5_put(struct kvm_vcpu *vcpu)
> >  	kvm_call_hyp(__vgic_v5_save_apr, cpu_if);
> >  
> >  	cpu_if->gicv5_vpe.resident = false;
> > +
> > +	/* The shadow priority is only updated on entering WFI */
> > +	if (vcpu_get_flag(vcpu, IN_WFI))
> > +		vgic_v5_sync_ppi_priorities(vcpu);
> >  }
> >  
> >  void vgic_v5_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr
> > *vmcrp)
> > diff --git a/arch/arm64/kvm/vgic/vgic.c
> > b/arch/arm64/kvm/vgic/vgic.c
> > index 3b148d3d4875e..d448205d80617 100644
> > --- a/arch/arm64/kvm/vgic/vgic.c
> > +++ b/arch/arm64/kvm/vgic/vgic.c
> > @@ -1230,6 +1230,9 @@ int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu
> > *vcpu)
> >  	unsigned long flags;
> >  	struct vgic_vmcr vmcr;
> >  
> > +	if (vgic_is_v5(vcpu->kvm))
> > +		return vgic_v5_has_pending_ppi(vcpu);
> > +
> >  	if (!vcpu->kvm->arch.vgic.enabled)
> >  		return false;
> >  
> > diff --git a/arch/arm64/kvm/vgic/vgic.h
> > b/arch/arm64/kvm/vgic/vgic.h
> > index ef4e3fb7159dd..3a9e610eefb00 100644
> > --- a/arch/arm64/kvm/vgic/vgic.h
> > +++ b/arch/arm64/kvm/vgic/vgic.h
> > @@ -365,6 +365,7 @@ void vgic_debug_destroy(struct kvm *kvm);
> >  
> >  int vgic_v5_probe(const struct gic_kvm_info *info);
> >  void vgic_v5_set_ppi_ops(struct vgic_irq *irq);
> > +bool vgic_v5_has_pending_ppi(struct kvm_vcpu *vcpu);
> >  void vgic_v5_flush_ppi_state(struct kvm_vcpu *vcpu);
> >  void vgic_v5_fold_ppi_state(struct kvm_vcpu *vcpu);
> >  void vgic_v5_load(struct kvm_vcpu *vcpu);
> 
> Thanks,
> 
> 	M.
> 

[PATCH v6 23/39] KVM: arm64: gic-v5: Trap and mask guest ICC_PPI_ENABLERx_EL1 writes

[Sascha Bischoff]

A guest should not be able to detect if a PPI that is not exposed to
the guest is implemented or not. Avoid the guest enabling any PPIs
that are not implemented as far as the guest is concerned by trapping
and masking writes to the two ICC_PPI_ENABLERx_EL1 registers.

When a guest writes these registers, the write is masked with the set
of PPIs actually exposed to the guest, and the state is written back
to KVM's shadow state. As there is now no way for the guest to change
the PPI enable state without it being trapped, saving of the PPI
Enable state is dropped from guest exit.

Reads for the above registers are not masked. When the guest is
running and reads from the above registers, it is presented with what
KVM provides in the ICH_PPI_ENABLERx_EL2 registers, which is the
masked version of what the guest last wrote.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
---
 arch/arm64/include/asm/kvm_host.h |  1 -
 arch/arm64/kvm/config.c           | 13 +++++++-
 arch/arm64/kvm/hyp/vgic-v5-sr.c   |  4 ---
 arch/arm64/kvm/sys_regs.c         | 50 +++++++++++++++++++++++++++++++
 4 files changed, 62 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index c4a172b702063..a7dc0aac3b934 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -814,7 +814,6 @@ struct kvm_host_data {
 
 		/* The saved state of the regs when leaving the guest */
 		DECLARE_BITMAP(activer_exit, VGIC_V5_NR_PRIVATE_IRQS);
-		DECLARE_BITMAP(enabler_exit, VGIC_V5_NR_PRIVATE_IRQS);
 	} vgic_v5_ppi_state;
 };
 
diff --git a/arch/arm64/kvm/config.c b/arch/arm64/kvm/config.c
index 5663f25905e83..e14685343191b 100644
--- a/arch/arm64/kvm/config.c
+++ b/arch/arm64/kvm/config.c
@@ -1699,6 +1699,17 @@ static void __compute_ich_hfgrtr(struct kvm_vcpu *vcpu)
 					     ICH_HFGRTR_EL2_ICC_IDRn_EL1);
 }
 
+static void __compute_ich_hfgwtr(struct kvm_vcpu *vcpu)
+{
+	__compute_fgt(vcpu, ICH_HFGWTR_EL2);
+
+	/*
+	 * We present a different subset of PPIs the guest from what
+	 * exist in real hardware. We only trap writes, not reads.
+	 */
+	*vcpu_fgt(vcpu, ICH_HFGWTR_EL2) &= ~(ICH_HFGWTR_EL2_ICC_PPI_ENABLERn_EL1);
+}
+
 void kvm_vcpu_load_fgt(struct kvm_vcpu *vcpu)
 {
 	if (!cpus_have_final_cap(ARM64_HAS_FGT))
@@ -1721,7 +1732,7 @@ void kvm_vcpu_load_fgt(struct kvm_vcpu *vcpu)
 
 	if (cpus_have_final_cap(ARM64_HAS_GICV5_CPUIF)) {
 		__compute_ich_hfgrtr(vcpu);
-		__compute_fgt(vcpu, ICH_HFGWTR_EL2);
+		__compute_ich_hfgwtr(vcpu);
 		__compute_fgt(vcpu, ICH_HFGITR_EL2);
 	}
 }
diff --git a/arch/arm64/kvm/hyp/vgic-v5-sr.c b/arch/arm64/kvm/hyp/vgic-v5-sr.c
index f34ea219cc4e9..2c4304ffa9f33 100644
--- a/arch/arm64/kvm/hyp/vgic-v5-sr.c
+++ b/arch/arm64/kvm/hyp/vgic-v5-sr.c
@@ -37,8 +37,6 @@ void __vgic_v5_save_ppi_state(struct vgic_v5_cpu_if *cpu_if)
 
 	bitmap_write(host_data_ptr(vgic_v5_ppi_state)->activer_exit,
 		     read_sysreg_s(SYS_ICH_PPI_ACTIVER0_EL2), 0, 64);
-	bitmap_write(host_data_ptr(vgic_v5_ppi_state)->enabler_exit,
-		     read_sysreg_s(SYS_ICH_PPI_ENABLER0_EL2), 0, 64);
 	bitmap_write(host_data_ptr(vgic_v5_ppi_state)->pendr_exit,
 		     read_sysreg_s(SYS_ICH_PPI_PENDR0_EL2), 0, 64);
 
@@ -54,8 +52,6 @@ void __vgic_v5_save_ppi_state(struct vgic_v5_cpu_if *cpu_if)
 	if (VGIC_V5_NR_PRIVATE_IRQS == 128) {
 		bitmap_write(host_data_ptr(vgic_v5_ppi_state)->activer_exit,
 			     read_sysreg_s(SYS_ICH_PPI_ACTIVER1_EL2), 64, 64);
-		bitmap_write(host_data_ptr(vgic_v5_ppi_state)->enabler_exit,
-			     read_sysreg_s(SYS_ICH_PPI_ENABLER1_EL2), 64, 64);
 		bitmap_write(host_data_ptr(vgic_v5_ppi_state)->pendr_exit,
 			     read_sysreg_s(SYS_ICH_PPI_PENDR1_EL2), 64, 64);
 
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 85300e76bbe46..e1001544d4f40 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -718,6 +718,54 @@ static bool access_gicv5_iaffid(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
 	return true;
 }
 
+static bool access_gicv5_ppi_enabler(struct kvm_vcpu *vcpu,
+				     struct sys_reg_params *p,
+				     const struct sys_reg_desc *r)
+{
+	unsigned long *mask = vcpu->kvm->arch.vgic.gicv5_vm.vgic_ppi_mask;
+	struct vgic_v5_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v5;
+	int i;
+
+	/* We never expect to get here with a read! */
+	if (WARN_ON_ONCE(!p->is_write))
+		return undef_access(vcpu, p, r);
+
+	/*
+	 * If we're only handling architected PPIs and the guest writes to the
+	 * enable for the non-architected PPIs, we just return as there's
+	 * nothing to do at all. We don't even allocate the storage for them in
+	 * this case.
+	 */
+	if (VGIC_V5_NR_PRIVATE_IRQS == 64 && p->Op2 % 2)
+		return true;
+
+	/*
+	 * Merge the raw guest write into out bitmap at an offset of either 0 or
+	 * 64, then and it with our PPI mask.
+	 */
+	bitmap_write(cpu_if->vgic_ppi_enabler, p->regval, 64 * (p->Op2 % 2), 64);
+	bitmap_and(cpu_if->vgic_ppi_enabler, cpu_if->vgic_ppi_enabler, mask,
+		   VGIC_V5_NR_PRIVATE_IRQS);
+
+	/*
+	 * Sync the change in enable states to the vgic_irqs. We consider all
+	 * PPIs as we don't expose many to the guest.
+	 */
+	for_each_set_bit(i, mask, VGIC_V5_NR_PRIVATE_IRQS) {
+		u32 intid = vgic_v5_make_ppi(i);
+		struct vgic_irq *irq;
+
+		irq = vgic_get_vcpu_irq(vcpu, intid);
+
+		scoped_guard(raw_spinlock_irqsave, &irq->irq_lock)
+			irq->enabled = test_bit(i, cpu_if->vgic_ppi_enabler);
+
+		vgic_put_irq(vcpu->kvm, irq);
+	}
+
+	return true;
+}
+
 static bool trap_raz_wi(struct kvm_vcpu *vcpu,
 			struct sys_reg_params *p,
 			const struct sys_reg_desc *r)
@@ -3444,6 +3492,8 @@ static const struct sys_reg_desc sys_reg_descs[] = {
 	{ SYS_DESC(SYS_ICC_AP1R3_EL1), undef_access },
 	{ SYS_DESC(SYS_ICC_IDR0_EL1), access_gicv5_idr0 },
 	{ SYS_DESC(SYS_ICC_IAFFIDR_EL1), access_gicv5_iaffid },
+	{ SYS_DESC(SYS_ICC_PPI_ENABLER0_EL1), access_gicv5_ppi_enabler },
+	{ SYS_DESC(SYS_ICC_PPI_ENABLER1_EL1), access_gicv5_ppi_enabler },
 	{ SYS_DESC(SYS_ICC_DIR_EL1), access_gic_dir },
 	{ SYS_DESC(SYS_ICC_RPR_EL1), undef_access },
 	{ SYS_DESC(SYS_ICC_SGI1R_EL1), access_gic_sgi },
-- 
2.34.1

[PATCH v6 24/39] KVM: arm64: Introduce set_direct_injection irq_op

[Sascha Bischoff]

GICv5 adds support for directly injected PPIs. The mechanism for
setting this up is GICv5 specific, so rather than adding
GICv5-specific code to the common vgic code, we introduce a new
irq_op.

This new irq_op is intended to be used to enable or disable direct
injection for interrupts that support it. As it is an irq_op, it has
no effect unless explicitly populated in the irq_ops structure for a
particular interrupt.  The usage is demonstracted in the subsequent
change.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
---
 arch/arm64/kvm/vgic/vgic.c | 7 +++++++
 include/kvm/arm_vgic.h     | 7 +++++++
 2 files changed, 14 insertions(+)

diff --git a/arch/arm64/kvm/vgic/vgic.c b/arch/arm64/kvm/vgic/vgic.c
index d448205d80617..d7407337f9d26 100644
--- a/arch/arm64/kvm/vgic/vgic.c
+++ b/arch/arm64/kvm/vgic/vgic.c
@@ -619,12 +619,19 @@ static int kvm_vgic_map_irq(struct kvm_vcpu *vcpu, struct vgic_irq *irq,
 	irq->hw = true;
 	irq->host_irq = host_irq;
 	irq->hwintid = data->hwirq;
+
+	if (irq->ops && irq->ops->set_direct_injection)
+		irq->ops->set_direct_injection(vcpu, irq, true);
+
 	return 0;
 }
 
 /* @irq->irq_lock must be held */
 static inline void kvm_vgic_unmap_irq(struct vgic_irq *irq)
 {
+	if (irq->ops && irq->ops->set_direct_injection)
+		irq->ops->set_direct_injection(irq->target_vcpu, irq, false);
+
 	irq->hw = false;
 	irq->hwintid = 0;
 }
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index e9797c5dbbf0c..a28cf765f3eb5 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -215,6 +215,13 @@ struct irq_ops {
 	 */
 	bool (*queue_irq_unlock)(struct kvm *kvm, struct vgic_irq *irq,
 				unsigned long flags) __releases(&irq->irq_lock);
+
+	/*
+	 * Callback function pointer to either enable or disable direct
+	 * injection for a mapped interrupt.
+	 */
+	void (*set_direct_injection)(struct kvm_vcpu *vcpu,
+				     struct vgic_irq *irq, bool direct);
 };
 
 struct vgic_irq {
-- 
2.34.1

[PATCH v6 25/39] KVM: arm64: gic-v5: Implement direct injection of PPIs

[Sascha Bischoff]

GICv5 is able to directly inject PPI pending state into a guest using
a mechanism called DVI whereby the pending bit for a paticular PPI is
driven directly by the physically-connected hardware. This mechanism
itself doesn't allow for any ID translation, so the host interrupt is
directly mapped into a guest with the same interrupt ID.

When mapping a virtual interrupt to a physical interrupt via
kvm_vgic_map_irq for a GICv5 guest, check if the interrupt itself is a
PPI or not. If it is, and the host's interrupt ID matches that used
for the guest DVI is enabled, and the interrupt itself is marked as
directly_injected.

When the interrupt is unmapped again, this process is reversed, and
DVI is disabled for the interrupt again.

Note: the expectation is that a directly injected PPI is disabled on
the host while the guest state is loaded. The reason is that although
DVI is enabled to drive the guest's pending state directly, the host
pending state also remains driven. In order to avoid the same PPI
firing on both the host and the guest, the host's interrupt must be
disabled (masked). This is left up to the code that owns the device
generating the PPI as this needs to be handled on a per-VM basis. One
VM might use DVI, while another might not, in which case the physical
PPI should be enabled for the latter.

Co-authored-by: Timothy Hayes <timothy.hayes@arm.com>
Signed-off-by: Timothy Hayes <timothy.hayes@arm.com>
Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
---
 arch/arm64/kvm/vgic/vgic-v5.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/arch/arm64/kvm/vgic/vgic-v5.c b/arch/arm64/kvm/vgic/vgic-v5.c
index 14dba634f79b4..602a970118496 100644
--- a/arch/arm64/kvm/vgic/vgic-v5.c
+++ b/arch/arm64/kvm/vgic/vgic-v5.c
@@ -180,8 +180,24 @@ static bool vgic_v5_ppi_queue_irq_unlock(struct kvm *kvm, struct vgic_irq *irq,
 	return false;
 }
 
+/*
+ * Sets/clears the corresponding bit in the ICH_PPI_DVIR register.
+ */
+static void vgic_v5_set_ppi_dvi(struct kvm_vcpu *vcpu, struct vgic_irq *irq,
+				bool dvi)
+{
+	struct vgic_v5_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v5;
+	u32 ppi;
+
+	lockdep_assert_held(&irq->irq_lock);
+
+	ppi = vgic_v5_get_hwirq_id(irq->intid);
+	__assign_bit(ppi, cpu_if->vgic_ppi_dvir, dvi);
+}
+
 static struct irq_ops vgic_v5_ppi_irq_ops = {
 	.queue_irq_unlock = vgic_v5_ppi_queue_irq_unlock,
+	.set_direct_injection = vgic_v5_set_ppi_dvi,
 };
 
 void vgic_v5_set_ppi_ops(struct vgic_irq *irq)
-- 
2.34.1

[PATCH v6 26/39] KVM: arm64: gic-v5: Support GICv5 interrupts with KVM_IRQ_LINE

[Sascha Bischoff]

Interrupts under GICv5 look quite different to those from older Arm
GICs. Specifically, the type is encoded in the top bits of the
interrupt ID.

Extend KVM_IRQ_LINE to cope with GICv5 PPIs and SPIs. The requires
subtly changing the KVM_IRQ_LINE API for GICv5 guests. For older Arm
GICs, PPIs had to be in the range of 16-31, and SPIs had to be
32-1019, but this no longer holds true for GICv5. Instead, for a GICv5
guest support PPIs in the range of 0-127, and SPIs in the range
0-65535. The documentation is updated accordingly.

The SPI range doesn't cover the full SPI range that a GICv5 system can
potentially cope with (GICv5 provides up to 24-bits of SPI ID space,
and we only have 16 bits to work with in KVM_IRQ_LINE). However, 65k
SPIs is more than would be reasonably expected on systems for years to
come.

In order to use vgic_is_v5(), the kvm/arm_vgic.h header is added to
kvm/arm.c.

Note: As the GICv5 KVM implementation currently doesn't support
injecting SPIs attempts to do so will fail. This restriction will by
lifted as the GICv5 KVM support evolves.

Co-authored-by: Timothy Hayes <timothy.hayes@arm.com>
Signed-off-by: Timothy Hayes <timothy.hayes@arm.com>
Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
---
 Documentation/virt/kvm/api.rst |  6 ++++--
 arch/arm64/kvm/arm.c           | 22 +++++++++++++++++++---
 arch/arm64/kvm/vgic/vgic.c     |  4 ++++
 3 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index 032516783e962..03d87d9b97d94 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -907,10 +907,12 @@ The irq_type field has the following values:
 - KVM_ARM_IRQ_TYPE_CPU:
 	       out-of-kernel GIC: irq_id 0 is IRQ, irq_id 1 is FIQ
 - KVM_ARM_IRQ_TYPE_SPI:
-	       in-kernel GIC: SPI, irq_id between 32 and 1019 (incl.)
+	       in-kernel GICv2/GICv3: SPI, irq_id between 32 and 1019 (incl.)
                (the vcpu_index field is ignored)
+	       in-kernel GICv5: SPI, irq_id between 0 and 65535 (incl.)
 - KVM_ARM_IRQ_TYPE_PPI:
-	       in-kernel GIC: PPI, irq_id between 16 and 31 (incl.)
+	       in-kernel GICv2/GICv3: PPI, irq_id between 16 and 31 (incl.)
+	       in-kernel GICv5: PPI, irq_id between 0 and 127 (incl.)
 
 (The irq_id field thus corresponds nicely to the IRQ ID in the ARM GIC specs)
 
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index f68c4036afebd..8577d7dd4d1ef 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -45,6 +45,9 @@
 #include <kvm/arm_hypercalls.h>
 #include <kvm/arm_pmu.h>
 #include <kvm/arm_psci.h>
+#include <kvm/arm_vgic.h>
+
+#include <linux/irqchip/arm-gic-v5.h>
 
 #include "sys_regs.h"
 
@@ -1479,16 +1482,29 @@ int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level,
 		if (!vcpu)
 			return -EINVAL;
 
-		if (irq_num < VGIC_NR_SGIS || irq_num >= VGIC_NR_PRIVATE_IRQS)
+		if (vgic_is_v5(kvm)) {
+			if (irq_num >= VGIC_V5_NR_PRIVATE_IRQS)
+				return -EINVAL;
+
+			/* Build a GICv5-style IntID here */
+			irq_num = vgic_v5_make_ppi(irq_num);
+		} else if (irq_num < VGIC_NR_SGIS ||
+			   irq_num >= VGIC_NR_PRIVATE_IRQS) {
 			return -EINVAL;
+		}
 
 		return kvm_vgic_inject_irq(kvm, vcpu, irq_num, level, NULL);
 	case KVM_ARM_IRQ_TYPE_SPI:
 		if (!irqchip_in_kernel(kvm))
 			return -ENXIO;
 
-		if (irq_num < VGIC_NR_PRIVATE_IRQS)
-			return -EINVAL;
+		if (vgic_is_v5(kvm)) {
+			/* Build a GICv5-style IntID here */
+			irq_num = vgic_v5_make_spi(irq_num);
+		} else {
+			if (irq_num < VGIC_NR_PRIVATE_IRQS)
+				return -EINVAL;
+		}
 
 		return kvm_vgic_inject_irq(kvm, NULL, irq_num, level, NULL);
 	}
diff --git a/arch/arm64/kvm/vgic/vgic.c b/arch/arm64/kvm/vgic/vgic.c
index d7407337f9d26..ab1c92902b41b 100644
--- a/arch/arm64/kvm/vgic/vgic.c
+++ b/arch/arm64/kvm/vgic/vgic.c
@@ -86,6 +86,10 @@ static struct vgic_irq *vgic_get_lpi(struct kvm *kvm, u32 intid)
  */
 struct vgic_irq *vgic_get_irq(struct kvm *kvm, u32 intid)
 {
+	/* Non-private IRQs are not yet implemented for GICv5 */
+	if (vgic_is_v5(kvm))
+		return NULL;
+
 	/* SPIs */
 	if (intid >= VGIC_NR_PRIVATE_IRQS &&
 	    intid < (kvm->arch.vgic.nr_spis + VGIC_NR_PRIVATE_IRQS)) {
-- 
2.34.1

[PATCH v6 27/39] KVM: arm64: gic-v5: Create and initialise vgic_v5

[Sascha Bischoff]

Update kvm_vgic_create to create a vgic_v5 device. When creating a
vgic, FEAT_GCIE in the ID_AA64PFR2 is only exposed to vgic_v5-based
guests, and is hidden otherwise. GIC in ~ID_AA64PFR0_EL1 is never
exposed for a vgic_v5 guest.

When initialising a vgic_v5, skip kvm_vgic_dist_init as GICv5 doesn't
support one. The current vgic_v5 implementation only supports PPIs, so
no SPIs are initialised either.

The current vgic_v5 support doesn't extend to nested guests. Therefore,
the init of vgic_v5 for a nested guest is failed in vgic_v5_init.

As the current vgic_v5 doesn't require any resources to be mapped,
vgic_v5_map_resources is simply used to check that the vgic has indeed
been initialised. Again, this will change as more GICv5 support is
merged in.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
---
 arch/arm64/kvm/vgic/vgic-init.c | 54 +++++++++++++++++++++------------
 arch/arm64/kvm/vgic/vgic-v5.c   | 26 ++++++++++++++++
 arch/arm64/kvm/vgic/vgic.h      |  2 ++
 include/kvm/arm_vgic.h          |  1 +
 4 files changed, 63 insertions(+), 20 deletions(-)

diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c
index f8d7d5a895e79..13d085bf01a97 100644
--- a/arch/arm64/kvm/vgic/vgic-init.c
+++ b/arch/arm64/kvm/vgic/vgic-init.c
@@ -66,7 +66,7 @@ static int vgic_allocate_private_irqs_locked(struct kvm_vcpu *vcpu, u32 type);
  * or through the generic KVM_CREATE_DEVICE API ioctl.
  * irqchip_in_kernel() tells you if this function succeeded or not.
  * @kvm: kvm struct pointer
- * @type: KVM_DEV_TYPE_ARM_VGIC_V[23]
+ * @type: KVM_DEV_TYPE_ARM_VGIC_V[235]
  */
 int kvm_vgic_create(struct kvm *kvm, u32 type)
 {
@@ -131,8 +131,11 @@ int kvm_vgic_create(struct kvm *kvm, u32 type)
 
 	if (type == KVM_DEV_TYPE_ARM_VGIC_V2)
 		kvm->max_vcpus = VGIC_V2_MAX_CPUS;
-	else
+	else if (type == KVM_DEV_TYPE_ARM_VGIC_V3)
 		kvm->max_vcpus = VGIC_V3_MAX_CPUS;
+	else if (type == KVM_DEV_TYPE_ARM_VGIC_V5)
+		kvm->max_vcpus = min(VGIC_V5_MAX_CPUS,
+				     kvm_vgic_global_state.max_gic_vcpus);
 
 	if (atomic_read(&kvm->online_vcpus) > kvm->max_vcpus) {
 		ret = -E2BIG;
@@ -425,22 +428,28 @@ int vgic_init(struct kvm *kvm)
 	if (kvm->created_vcpus != atomic_read(&kvm->online_vcpus))
 		return -EBUSY;
 
-	/* freeze the number of spis */
-	if (!dist->nr_spis)
-		dist->nr_spis = VGIC_NR_IRQS_LEGACY - VGIC_NR_PRIVATE_IRQS;
+	if (!vgic_is_v5(kvm)) {
+		/* freeze the number of spis */
+		if (!dist->nr_spis)
+			dist->nr_spis = VGIC_NR_IRQS_LEGACY - VGIC_NR_PRIVATE_IRQS;
 
-	ret = kvm_vgic_dist_init(kvm, dist->nr_spis);
-	if (ret)
-		goto out;
+		ret = kvm_vgic_dist_init(kvm, dist->nr_spis);
+		if (ret)
+			return ret;
 
-	/*
-	 * Ensure vPEs are allocated if direct IRQ injection (e.g. vSGIs,
-	 * vLPIs) is supported.
-	 */
-	if (vgic_supports_direct_irqs(kvm)) {
-		ret = vgic_v4_init(kvm);
+		/*
+		 * Ensure vPEs are allocated if direct IRQ injection (e.g. vSGIs,
+		 * vLPIs) is supported.
+		 */
+		if (vgic_supports_direct_irqs(kvm)) {
+			ret = vgic_v4_init(kvm);
+			if (ret)
+				return ret;
+		}
+	} else {
+		ret = vgic_v5_init(kvm);
 		if (ret)
-			goto out;
+			return ret;
 	}
 
 	kvm_for_each_vcpu(idx, vcpu, kvm)
@@ -448,12 +457,12 @@ int vgic_init(struct kvm *kvm)
 
 	ret = kvm_vgic_setup_default_irq_routing(kvm);
 	if (ret)
-		goto out;
+		return ret;
 
 	vgic_debug_init(kvm);
 	dist->initialized = true;
-out:
-	return ret;
+
+	return 0;
 }
 
 static void kvm_vgic_dist_destroy(struct kvm *kvm)
@@ -597,6 +606,7 @@ int vgic_lazy_init(struct kvm *kvm)
 int kvm_vgic_map_resources(struct kvm *kvm)
 {
 	struct vgic_dist *dist = &kvm->arch.vgic;
+	bool needs_dist = true;
 	enum vgic_type type;
 	gpa_t dist_base;
 	int ret = 0;
@@ -615,12 +625,16 @@ int kvm_vgic_map_resources(struct kvm *kvm)
 	if (dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V2) {
 		ret = vgic_v2_map_resources(kvm);
 		type = VGIC_V2;
-	} else {
+	} else if (dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3) {
 		ret = vgic_v3_map_resources(kvm);
 		type = VGIC_V3;
+	} else {
+		ret = vgic_v5_map_resources(kvm);
+		type = VGIC_V5;
+		needs_dist = false;
 	}
 
-	if (ret)
+	if (ret || !needs_dist)
 		goto out;
 
 	dist_base = dist->vgic_dist_base;
diff --git a/arch/arm64/kvm/vgic/vgic-v5.c b/arch/arm64/kvm/vgic/vgic-v5.c
index 602a970118496..0482282d59830 100644
--- a/arch/arm64/kvm/vgic/vgic-v5.c
+++ b/arch/arm64/kvm/vgic/vgic-v5.c
@@ -87,6 +87,32 @@ int vgic_v5_probe(const struct gic_kvm_info *info)
 	return 0;
 }
 
+int vgic_v5_init(struct kvm *kvm)
+{
+	struct kvm_vcpu *vcpu;
+	unsigned long idx;
+
+	if (vgic_initialized(kvm))
+		return 0;
+
+	kvm_for_each_vcpu(idx, vcpu, kvm) {
+		if (vcpu_has_nv(vcpu)) {
+			kvm_err("Nested GICv5 VMs are currently unsupported\n");
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+int vgic_v5_map_resources(struct kvm *kvm)
+{
+	if (!vgic_initialized(kvm))
+		return -EBUSY;
+
+	return 0;
+}
+
 int vgic_v5_finalize_ppi_state(struct kvm *kvm)
 {
 	struct kvm_vcpu *vcpu0;
diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h
index 3a9e610eefb00..9f1ddf9f4016c 100644
--- a/arch/arm64/kvm/vgic/vgic.h
+++ b/arch/arm64/kvm/vgic/vgic.h
@@ -364,6 +364,8 @@ void vgic_debug_init(struct kvm *kvm);
 void vgic_debug_destroy(struct kvm *kvm);
 
 int vgic_v5_probe(const struct gic_kvm_info *info);
+int vgic_v5_init(struct kvm *kvm);
+int vgic_v5_map_resources(struct kvm *kvm);
 void vgic_v5_set_ppi_ops(struct vgic_irq *irq);
 bool vgic_v5_has_pending_ppi(struct kvm_vcpu *vcpu);
 void vgic_v5_flush_ppi_state(struct kvm_vcpu *vcpu);
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index a28cf765f3eb5..a5ddccf7ef3b0 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -21,6 +21,7 @@
 #include <linux/irqchip/arm-gic-v4.h>
 #include <linux/irqchip/arm-gic-v5.h>
 
+#define VGIC_V5_MAX_CPUS	512
 #define VGIC_V3_MAX_CPUS	512
 #define VGIC_V2_MAX_CPUS	8
 #define VGIC_NR_IRQS_LEGACY     256
-- 
2.34.1

[PATCH v6 28/39] KVM: arm64: gic-v5: Initialise ID and priority bits when resetting vcpu

[Sascha Bischoff]

Determine the number of priority bits and ID bits exposed to the guest
as part of resetting the vcpu state. These values are presented to the
guest by trapping and emulating reads from ICC_IDR0_EL1.

GICv5 supports either 16- or 24-bits of ID space (for SPIs and
LPIs). It is expected that 2^16 IDs is more than enough, and therefore
this value is chosen irrespective of the hardware supporting more or
not.

The GICv5 architecture only supports 5 bits of priority in the CPU
interface (but potentially fewer in the IRS). Therefore, this is the
default value chosen for the number of priority bits in the CPU
IF.

Note: We replicate the way that GICv3 uses the num_id_bits and
num_pri_bits variables. That is, num_id_bits stores the value of the
hardware field verbatim (0 means 16-bits, 1 would mean 24-bits for
GICv5), and num_pri_bits stores the actual number of priority bits;
the field value + 1.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
---
 arch/arm64/kvm/vgic/vgic-init.c |  6 +++++-
 arch/arm64/kvm/vgic/vgic-v5.c   | 15 +++++++++++++++
 arch/arm64/kvm/vgic/vgic.h      |  1 +
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c
index 13d085bf01a97..497d4dc84913c 100644
--- a/arch/arm64/kvm/vgic/vgic-init.c
+++ b/arch/arm64/kvm/vgic/vgic-init.c
@@ -397,7 +397,11 @@ int kvm_vgic_vcpu_init(struct kvm_vcpu *vcpu)
 
 static void kvm_vgic_vcpu_reset(struct kvm_vcpu *vcpu)
 {
-	if (kvm_vgic_global_state.type == VGIC_V2)
+	const struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+
+	if (dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V5)
+		vgic_v5_reset(vcpu);
+	else if (kvm_vgic_global_state.type == VGIC_V2)
 		vgic_v2_reset(vcpu);
 	else
 		vgic_v3_reset(vcpu);
diff --git a/arch/arm64/kvm/vgic/vgic-v5.c b/arch/arm64/kvm/vgic/vgic-v5.c
index 0482282d59830..95c5fc51d180c 100644
--- a/arch/arm64/kvm/vgic/vgic-v5.c
+++ b/arch/arm64/kvm/vgic/vgic-v5.c
@@ -87,6 +87,21 @@ int vgic_v5_probe(const struct gic_kvm_info *info)
 	return 0;
 }
 
+void vgic_v5_reset(struct kvm_vcpu *vcpu)
+{
+	/*
+	 * We always present 16-bits of ID space to the guest, irrespective of
+	 * the host allowing more.
+	 */
+	vcpu->arch.vgic_cpu.num_id_bits = ICC_IDR0_EL1_ID_BITS_16BITS;
+
+	/*
+	 * The GICv5 architeture only supports 5-bits of priority in the
+	 * CPUIF (but potentially fewer in the IRS).
+	 */
+	vcpu->arch.vgic_cpu.num_pri_bits = 5;
+}
+
 int vgic_v5_init(struct kvm *kvm)
 {
 	struct kvm_vcpu *vcpu;
diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h
index 9f1ddf9f4016c..103913528450b 100644
--- a/arch/arm64/kvm/vgic/vgic.h
+++ b/arch/arm64/kvm/vgic/vgic.h
@@ -364,6 +364,7 @@ void vgic_debug_init(struct kvm *kvm);
 void vgic_debug_destroy(struct kvm *kvm);
 
 int vgic_v5_probe(const struct gic_kvm_info *info);
+void vgic_v5_reset(struct kvm_vcpu *vcpu);
 int vgic_v5_init(struct kvm *kvm);
 int vgic_v5_map_resources(struct kvm *kvm);
 void vgic_v5_set_ppi_ops(struct vgic_irq *irq);
-- 
2.34.1

[PATCH v6 29/39] KVM: arm64: gic-v5: Enlighten arch timer for GICv5

[Sascha Bischoff]

Now that GICv5 has arrived, the arch timer requires some TLC to
address some of the key differences introduced with GICv5.

For PPIs on GICv5, the queue_irq_unlock irq_op is used as AP lists are
not required at all for GICv5. The arch timer also introduces an
irq_op - get_input_level. Extend the arch-timer-provided irq_ops to
include the PPI op for vgic_v5 guests.

When possible, DVI (Direct Virtual Interrupt) is set for PPIs when
using a vgic_v5, which directly inject the pending state into the
guest. This means that the host never sees the interrupt for the guest
for these interrupts. This has three impacts.

* First of all, the kvm_cpu_has_pending_timer check is updated to
  explicitly check if the timers are expected to fire.

* Secondly, for mapped timers (which use DVI) they must be masked on
  the host prior to entering a GICv5 guest, and unmasked on the return
  path. This is handled in set_timer_irq_phys_masked.

* Thirdly, it makes zero sense to attempt to inject state for a DVI'd
  interrupt. Track which timers are direct, and skip the call to
  kvm_vgic_inject_irq() for these.

The final, but rather important, change is that the architected PPIs
for the timers are made mandatory for a GICv5 guest. Attempts to set
them to anything else are actively rejected. Once a vgic_v5 is
initialised, the arch timer PPIs are also explicitly reinitialised to
ensure the correct GICv5-compatible PPIs are used - this also adds in
the GICv5 PPI type to the intid.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
---
 arch/arm64/kvm/arch_timer.c     | 110 ++++++++++++++++++++++++++------
 arch/arm64/kvm/vgic/vgic-init.c |   9 +++
 arch/arm64/kvm/vgic/vgic-v5.c   |   7 +-
 include/kvm/arm_arch_timer.h    |  11 +++-
 include/kvm/arm_vgic.h          |   3 +
 5 files changed, 115 insertions(+), 25 deletions(-)

diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c
index 53312b88c342d..4575c36cae537 100644
--- a/arch/arm64/kvm/arch_timer.c
+++ b/arch/arm64/kvm/arch_timer.c
@@ -56,6 +56,12 @@ static struct irq_ops arch_timer_irq_ops = {
 	.get_input_level = kvm_arch_timer_get_input_level,
 };
 
+static struct irq_ops arch_timer_irq_ops_vgic_v5 = {
+	.get_input_level = kvm_arch_timer_get_input_level,
+	.queue_irq_unlock = vgic_v5_ppi_queue_irq_unlock,
+	.set_direct_injection = vgic_v5_set_ppi_dvi,
+};
+
 static int nr_timers(struct kvm_vcpu *vcpu)
 {
 	if (!vcpu_has_nv(vcpu))
@@ -177,6 +183,10 @@ void get_timer_map(struct kvm_vcpu *vcpu, struct timer_map *map)
 		map->emul_ptimer = vcpu_ptimer(vcpu);
 	}
 
+	map->direct_vtimer->direct = true;
+	if (map->direct_ptimer)
+		map->direct_ptimer->direct = true;
+
 	trace_kvm_get_timer_map(vcpu->vcpu_id, map);
 }
 
@@ -396,7 +406,11 @@ static bool kvm_timer_should_fire(struct arch_timer_context *timer_ctx)
 
 int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
 {
-	return vcpu_has_wfit_active(vcpu) && wfit_delay_ns(vcpu) == 0;
+	struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
+	struct arch_timer_context *ptimer = vcpu_ptimer(vcpu);
+
+	return kvm_timer_should_fire(vtimer) || kvm_timer_should_fire(ptimer) ||
+	       (vcpu_has_wfit_active(vcpu) && wfit_delay_ns(vcpu) == 0);
 }
 
 /*
@@ -447,6 +461,10 @@ static void kvm_timer_update_irq(struct kvm_vcpu *vcpu, bool new_level,
 	if (userspace_irqchip(vcpu->kvm))
 		return;
 
+	/* Skip injecting on GICv5 for directly injected (DVI'd) timers */
+	if (vgic_is_v5(vcpu->kvm) && timer_ctx->direct)
+		return;
+
 	kvm_vgic_inject_irq(vcpu->kvm, vcpu,
 			    timer_irq(timer_ctx),
 			    timer_ctx->irq.level,
@@ -657,6 +675,24 @@ static inline void set_timer_irq_phys_active(struct arch_timer_context *ctx, boo
 	WARN_ON(r);
 }
 
+/*
+ * On GICv5 we use DVI for the arch timer PPIs. This is restored later
+ * on as part of vgic_load. Therefore, in order to avoid the guest's
+ * interrupt making it to the host we mask it before entering the
+ * guest and unmask it again when we return.
+ */
+static inline void set_timer_irq_phys_masked(struct arch_timer_context *ctx, bool masked)
+{
+	if (masked) {
+		disable_percpu_irq(ctx->host_timer_irq);
+	} else {
+		if (ctx->host_timer_irq == host_vtimer_irq)
+			enable_percpu_irq(ctx->host_timer_irq, host_vtimer_irq_flags);
+		else
+			enable_percpu_irq(ctx->host_timer_irq, host_ptimer_irq_flags);
+	}
+}
+
 static void kvm_timer_vcpu_load_gic(struct arch_timer_context *ctx)
 {
 	struct kvm_vcpu *vcpu = timer_context_to_vcpu(ctx);
@@ -675,7 +711,10 @@ static void kvm_timer_vcpu_load_gic(struct arch_timer_context *ctx)
 
 	phys_active |= ctx->irq.level;
 
-	set_timer_irq_phys_active(ctx, phys_active);
+	if (!vgic_is_v5(vcpu->kvm))
+		set_timer_irq_phys_active(ctx, phys_active);
+	else
+		set_timer_irq_phys_masked(ctx, true);
 }
 
 static void kvm_timer_vcpu_load_nogic(struct kvm_vcpu *vcpu)
@@ -719,10 +758,14 @@ static void kvm_timer_vcpu_load_nested_switch(struct kvm_vcpu *vcpu,
 					      struct timer_map *map)
 {
 	int hw, ret;
+	struct irq_ops *ops;
 
 	if (!irqchip_in_kernel(vcpu->kvm))
 		return;
 
+	ops = vgic_is_v5(vcpu->kvm) ? &arch_timer_irq_ops_vgic_v5 :
+				      &arch_timer_irq_ops;
+
 	/*
 	 * We only ever unmap the vtimer irq on a VHE system that runs nested
 	 * virtualization, in which case we have both a valid emul_vtimer,
@@ -743,14 +786,14 @@ static void kvm_timer_vcpu_load_nested_switch(struct kvm_vcpu *vcpu,
 					    timer_irq(map->direct_vtimer));
 		if (!WARN_ON_ONCE(ret))
 			kvm_vgic_set_irq_ops(vcpu, timer_irq(map->direct_vtimer),
-					     &arch_timer_irq_ops);
+					     ops);
 
 		ret = kvm_vgic_map_phys_irq(vcpu,
 					    map->direct_ptimer->host_timer_irq,
 					    timer_irq(map->direct_ptimer));
 		if (!WARN_ON_ONCE(ret))
 			kvm_vgic_set_irq_ops(vcpu, timer_irq(map->direct_ptimer),
-					     &arch_timer_irq_ops);
+					     ops);
 	}
 }
 
@@ -867,7 +910,8 @@ void kvm_timer_vcpu_load(struct kvm_vcpu *vcpu)
 	get_timer_map(vcpu, &map);
 
 	if (static_branch_likely(&has_gic_active_state)) {
-		if (vcpu_has_nv(vcpu))
+		/* We don't do NV on GICv5, yet */
+		if (vcpu_has_nv(vcpu) && !vgic_is_v5(vcpu->kvm))
 			kvm_timer_vcpu_load_nested_switch(vcpu, &map);
 
 		kvm_timer_vcpu_load_gic(map.direct_vtimer);
@@ -937,6 +981,14 @@ void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu)
 
 	if (kvm_vcpu_is_blocking(vcpu))
 		kvm_timer_blocking(vcpu);
+
+	/* Unmask again on GICV5 */
+	if (vgic_is_v5(vcpu->kvm)) {
+		set_timer_irq_phys_masked(map.direct_vtimer, false);
+
+		if (map.direct_ptimer)
+			set_timer_irq_phys_masked(map.direct_ptimer, false);
+	}
 }
 
 void kvm_timer_sync_nested(struct kvm_vcpu *vcpu)
@@ -1100,10 +1152,19 @@ void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu)
 		      HRTIMER_MODE_ABS_HARD);
 }
 
+/*
+ * This is always called during kvm_arch_init_vm, but will also be
+ * called from kvm_vgic_create if we have a vGICv5.
+ */
 void kvm_timer_init_vm(struct kvm *kvm)
 {
+	/*
+	 * Set up the default PPIs - note that we adjust them based on
+	 * the model of the GIC as GICv5 uses a different way to
+	 * describing interrupts.
+	 */
 	for (int i = 0; i < NR_KVM_TIMERS; i++)
-		kvm->arch.timer_data.ppi[i] = default_ppi[i];
+		kvm->arch.timer_data.ppi[i] = get_vgic_ppi(kvm, default_ppi[i]);
 }
 
 void kvm_timer_cpu_up(void)
@@ -1355,6 +1416,7 @@ static int kvm_irq_init(struct arch_timer_kvm_info *info)
 		}
 
 		arch_timer_irq_ops.flags |= VGIC_IRQ_SW_RESAMPLE;
+		arch_timer_irq_ops_vgic_v5.flags |= VGIC_IRQ_SW_RESAMPLE;
 		WARN_ON(irq_domain_push_irq(domain, host_vtimer_irq,
 					    (void *)TIMER_VTIMER));
 	}
@@ -1505,10 +1567,13 @@ static bool timer_irqs_are_valid(struct kvm_vcpu *vcpu)
 			break;
 
 		/*
-		 * We know by construction that we only have PPIs, so
-		 * all values are less than 32.
+		 * We know by construction that we only have PPIs, so all values
+		 * are less than 32 for non-GICv5 VGICs. On GICv5, they are
+		 * architecturally defined to be under 32 too. However, we mask
+		 * off most of the bits as we might be presented with a GICv5
+		 * style PPI where the type is encoded in the top-bits.
 		 */
-		ppis |= BIT(irq);
+		ppis |= BIT(irq & 0x1f);
 	}
 
 	valid = hweight32(ppis) == nr_timers(vcpu);
@@ -1546,6 +1611,7 @@ int kvm_timer_enable(struct kvm_vcpu *vcpu)
 {
 	struct arch_timer_cpu *timer = vcpu_timer(vcpu);
 	struct timer_map map;
+	struct irq_ops *ops;
 	int ret;
 
 	if (timer->enabled)
@@ -1564,6 +1630,9 @@ int kvm_timer_enable(struct kvm_vcpu *vcpu)
 		return -EINVAL;
 	}
 
+	ops = vgic_is_v5(vcpu->kvm) ? &arch_timer_irq_ops_vgic_v5 :
+				      &arch_timer_irq_ops;
+
 	get_timer_map(vcpu, &map);
 
 	ret = kvm_vgic_map_phys_irq(vcpu,
@@ -1572,8 +1641,7 @@ int kvm_timer_enable(struct kvm_vcpu *vcpu)
 	if (ret)
 		return ret;
 
-	kvm_vgic_set_irq_ops(vcpu, timer_irq(map.direct_vtimer),
-			     &arch_timer_irq_ops);
+	kvm_vgic_set_irq_ops(vcpu, timer_irq(map.direct_vtimer), ops);
 
 	if (map.direct_ptimer) {
 		ret = kvm_vgic_map_phys_irq(vcpu,
@@ -1582,8 +1650,7 @@ int kvm_timer_enable(struct kvm_vcpu *vcpu)
 		if (ret)
 			return ret;
 
-		kvm_vgic_set_irq_ops(vcpu, timer_irq(map.direct_ptimer),
-				     &arch_timer_irq_ops);
+		kvm_vgic_set_irq_ops(vcpu, timer_irq(map.direct_ptimer), ops);
 	}
 
 no_vgic:
@@ -1612,12 +1679,11 @@ int kvm_arm_timer_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
 	if (!(irq_is_ppi(vcpu->kvm, irq)))
 		return -EINVAL;
 
-	mutex_lock(&vcpu->kvm->arch.config_lock);
+	guard(mutex)(&vcpu->kvm->arch.config_lock);
 
 	if (test_bit(KVM_ARCH_FLAG_TIMER_PPIS_IMMUTABLE,
 		     &vcpu->kvm->arch.flags)) {
-		ret = -EBUSY;
-		goto out;
+		return -EBUSY;
 	}
 
 	switch (attr->attr) {
@@ -1634,10 +1700,16 @@ int kvm_arm_timer_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
 		idx = TIMER_HPTIMER;
 		break;
 	default:
-		ret = -ENXIO;
-		goto out;
+		return -ENXIO;
 	}
 
+	/*
+	 * The PPIs for the Arch Timers are architecturally defined for
+	 * GICv5. Reject anything that changes them from the specified value.
+	 */
+	if (vgic_is_v5(vcpu->kvm) && vcpu->kvm->arch.timer_data.ppi[idx] != irq)
+		return -EINVAL;
+
 	/*
 	 * We cannot validate the IRQ unicity before we run, so take it at
 	 * face value. The verdict will be given on first vcpu run, for each
@@ -1645,8 +1717,6 @@ int kvm_arm_timer_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
 	 */
 	vcpu->kvm->arch.timer_data.ppi[idx] = irq;
 
-out:
-	mutex_unlock(&vcpu->kvm->arch.config_lock);
 	return ret;
 }
 
diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c
index 497d4dc84913c..f2fbd701d4831 100644
--- a/arch/arm64/kvm/vgic/vgic-init.c
+++ b/arch/arm64/kvm/vgic/vgic-init.c
@@ -173,6 +173,15 @@ int kvm_vgic_create(struct kvm *kvm, u32 type)
 	if (type == KVM_DEV_TYPE_ARM_VGIC_V3)
 		kvm->arch.vgic.nassgicap = system_supports_direct_sgis();
 
+	/*
+	 * We now know that we have a GICv5. The Arch Timer PPI interrupts may
+	 * have been initialised at this stage, but will have done so assuming
+	 * that we have an older GIC, meaning that the IntIDs won't be
+	 * correct. We init them again, and this time they will be correct.
+	 */
+	if (type == KVM_DEV_TYPE_ARM_VGIC_V5)
+		kvm_timer_init_vm(kvm);
+
 out_unlock:
 	mutex_unlock(&kvm->arch.config_lock);
 	kvm_unlock_all_vcpus(kvm);
diff --git a/arch/arm64/kvm/vgic/vgic-v5.c b/arch/arm64/kvm/vgic/vgic-v5.c
index 95c5fc51d180c..32565bfbd1051 100644
--- a/arch/arm64/kvm/vgic/vgic-v5.c
+++ b/arch/arm64/kvm/vgic/vgic-v5.c
@@ -192,8 +192,8 @@ static u32 vgic_v5_get_effective_priority_mask(struct kvm_vcpu *vcpu)
  * need the PPIs to be queued on a per-VCPU AP list. Therefore, sanity check the
  * state, unlock, and return.
  */
-static bool vgic_v5_ppi_queue_irq_unlock(struct kvm *kvm, struct vgic_irq *irq,
-					 unsigned long flags)
+bool vgic_v5_ppi_queue_irq_unlock(struct kvm *kvm, struct vgic_irq *irq,
+				  unsigned long flags)
 	__releases(&irq->irq_lock)
 {
 	struct kvm_vcpu *vcpu;
@@ -224,8 +224,7 @@ static bool vgic_v5_ppi_queue_irq_unlock(struct kvm *kvm, struct vgic_irq *irq,
 /*
  * Sets/clears the corresponding bit in the ICH_PPI_DVIR register.
  */
-static void vgic_v5_set_ppi_dvi(struct kvm_vcpu *vcpu, struct vgic_irq *irq,
-				bool dvi)
+void vgic_v5_set_ppi_dvi(struct kvm_vcpu *vcpu, struct vgic_irq *irq, bool dvi)
 {
 	struct vgic_v5_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v5;
 	u32 ppi;
diff --git a/include/kvm/arm_arch_timer.h b/include/kvm/arm_arch_timer.h
index 7310841f45121..a7754e0a2ef41 100644
--- a/include/kvm/arm_arch_timer.h
+++ b/include/kvm/arm_arch_timer.h
@@ -10,6 +10,8 @@
 #include <linux/clocksource.h>
 #include <linux/hrtimer.h>
 
+#include <linux/irqchip/arm-gic-v5.h>
+
 enum kvm_arch_timers {
 	TIMER_PTIMER,
 	TIMER_VTIMER,
@@ -47,7 +49,7 @@ struct arch_timer_vm_data {
 	u64	poffset;
 
 	/* The PPI for each timer, global to the VM */
-	u8	ppi[NR_KVM_TIMERS];
+	u32	ppi[NR_KVM_TIMERS];
 };
 
 struct arch_timer_context {
@@ -74,6 +76,9 @@ struct arch_timer_context {
 
 	/* Duplicated state from arch_timer.c for convenience */
 	u32				host_timer_irq;
+
+	/* Is this a direct timer? */
+	bool				direct;
 };
 
 struct timer_map {
@@ -130,6 +135,10 @@ void kvm_timer_init_vhe(void);
 #define timer_vm_data(ctx)		(&(timer_context_to_vcpu(ctx)->kvm->arch.timer_data))
 #define timer_irq(ctx)			(timer_vm_data(ctx)->ppi[arch_timer_ctx_index(ctx)])
 
+#define get_vgic_ppi(k, i) (((k)->arch.vgic.vgic_model != KVM_DEV_TYPE_ARM_VGIC_V5) ? \
+			    (i) : (FIELD_PREP(GICV5_HWIRQ_ID, i) |	\
+				   FIELD_PREP(GICV5_HWIRQ_TYPE, GICV5_HWIRQ_TYPE_PPI)))
+
 u64 kvm_arm_timer_read_sysreg(struct kvm_vcpu *vcpu,
 			      enum kvm_arch_timers tmr,
 			      enum kvm_arch_timer_regs treg);
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index a5ddccf7ef3b0..8cc3a7b4d8152 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -627,6 +627,9 @@ void vgic_v4_commit(struct kvm_vcpu *vcpu);
 int vgic_v4_put(struct kvm_vcpu *vcpu);
 
 int vgic_v5_finalize_ppi_state(struct kvm *kvm);
+bool vgic_v5_ppi_queue_irq_unlock(struct kvm *kvm, struct vgic_irq *irq,
+				  unsigned long flags);
+void vgic_v5_set_ppi_dvi(struct kvm_vcpu *vcpu, struct vgic_irq *irq, bool dvi);
 
 bool vgic_state_is_nested(struct kvm_vcpu *vcpu);
 
-- 
2.34.1

Re: [PATCH v6 29/39] KVM: arm64: gic-v5: Enlighten arch timer for GICv5

[Marc Zyngier]

On Tue, 17 Mar 2026 11:47:29 +0000,
Sascha Bischoff <Sascha.Bischoff@arm.com> wrote:
> 
> Now that GICv5 has arrived, the arch timer requires some TLC to
> address some of the key differences introduced with GICv5.
> 
> For PPIs on GICv5, the queue_irq_unlock irq_op is used as AP lists are
> not required at all for GICv5. The arch timer also introduces an
> irq_op - get_input_level. Extend the arch-timer-provided irq_ops to
> include the PPI op for vgic_v5 guests.
> 
> When possible, DVI (Direct Virtual Interrupt) is set for PPIs when
> using a vgic_v5, which directly inject the pending state into the
> guest. This means that the host never sees the interrupt for the guest
> for these interrupts. This has three impacts.
> 
> * First of all, the kvm_cpu_has_pending_timer check is updated to
>   explicitly check if the timers are expected to fire.
> 
> * Secondly, for mapped timers (which use DVI) they must be masked on
>   the host prior to entering a GICv5 guest, and unmasked on the return
>   path. This is handled in set_timer_irq_phys_masked.
> 
> * Thirdly, it makes zero sense to attempt to inject state for a DVI'd
>   interrupt. Track which timers are direct, and skip the call to
>   kvm_vgic_inject_irq() for these.
> 
> The final, but rather important, change is that the architected PPIs
> for the timers are made mandatory for a GICv5 guest. Attempts to set
> them to anything else are actively rejected. Once a vgic_v5 is
> initialised, the arch timer PPIs are also explicitly reinitialised to
> ensure the correct GICv5-compatible PPIs are used - this also adds in
> the GICv5 PPI type to the intid.
> 
> Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
> ---
>  arch/arm64/kvm/arch_timer.c     | 110 ++++++++++++++++++++++++++------
>  arch/arm64/kvm/vgic/vgic-init.c |   9 +++
>  arch/arm64/kvm/vgic/vgic-v5.c   |   7 +-
>  include/kvm/arm_arch_timer.h    |  11 +++-
>  include/kvm/arm_vgic.h          |   3 +
>  5 files changed, 115 insertions(+), 25 deletions(-)
> 
> diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c
> index 53312b88c342d..4575c36cae537 100644
> --- a/arch/arm64/kvm/arch_timer.c
> +++ b/arch/arm64/kvm/arch_timer.c
> @@ -56,6 +56,12 @@ static struct irq_ops arch_timer_irq_ops = {
>  	.get_input_level = kvm_arch_timer_get_input_level,
>  };
>  
> +static struct irq_ops arch_timer_irq_ops_vgic_v5 = {
> +	.get_input_level = kvm_arch_timer_get_input_level,
> +	.queue_irq_unlock = vgic_v5_ppi_queue_irq_unlock,
> +	.set_direct_injection = vgic_v5_set_ppi_dvi,
> +};
> +
>  static int nr_timers(struct kvm_vcpu *vcpu)
>  {
>  	if (!vcpu_has_nv(vcpu))
> @@ -177,6 +183,10 @@ void get_timer_map(struct kvm_vcpu *vcpu, struct timer_map *map)
>  		map->emul_ptimer = vcpu_ptimer(vcpu);
>  	}
>  
> +	map->direct_vtimer->direct = true;
> +	if (map->direct_ptimer)
> +		map->direct_ptimer->direct = true;
> +
>  	trace_kvm_get_timer_map(vcpu->vcpu_id, map);
>  }
>  
> @@ -396,7 +406,11 @@ static bool kvm_timer_should_fire(struct arch_timer_context *timer_ctx)
>  
>  int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
>  {
> -	return vcpu_has_wfit_active(vcpu) && wfit_delay_ns(vcpu) == 0;
> +	struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
> +	struct arch_timer_context *ptimer = vcpu_ptimer(vcpu);
> +
> +	return kvm_timer_should_fire(vtimer) || kvm_timer_should_fire(ptimer) ||
> +	       (vcpu_has_wfit_active(vcpu) && wfit_delay_ns(vcpu) == 0);
>  }
>  
>  /*
> @@ -447,6 +461,10 @@ static void kvm_timer_update_irq(struct kvm_vcpu *vcpu, bool new_level,
>  	if (userspace_irqchip(vcpu->kvm))
>  		return;
>  
> +	/* Skip injecting on GICv5 for directly injected (DVI'd) timers */
> +	if (vgic_is_v5(vcpu->kvm) && timer_ctx->direct)
> +		return;
> +
>  	kvm_vgic_inject_irq(vcpu->kvm, vcpu,
>  			    timer_irq(timer_ctx),
>  			    timer_ctx->irq.level,
> @@ -657,6 +675,24 @@ static inline void set_timer_irq_phys_active(struct arch_timer_context *ctx, boo
>  	WARN_ON(r);
>  }
>  
> +/*
> + * On GICv5 we use DVI for the arch timer PPIs. This is restored later
> + * on as part of vgic_load. Therefore, in order to avoid the guest's
> + * interrupt making it to the host we mask it before entering the
> + * guest and unmask it again when we return.
> + */
> +static inline void set_timer_irq_phys_masked(struct arch_timer_context *ctx, bool masked)
> +{
> +	if (masked) {
> +		disable_percpu_irq(ctx->host_timer_irq);
> +	} else {
> +		if (ctx->host_timer_irq == host_vtimer_irq)
> +			enable_percpu_irq(ctx->host_timer_irq, host_vtimer_irq_flags);
> +		else
> +			enable_percpu_irq(ctx->host_timer_irq, host_ptimer_irq_flags);
> +	}
> +}

I think this is missing a trick, which is to reuse the mask/unmask
infrastructure we use for the fruity crap. How about this following
untested hack?

diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c
index 600f250753b45..b29bea800e2ab 100644
--- a/arch/arm64/kvm/arch_timer.c
+++ b/arch/arm64/kvm/arch_timer.c
@@ -660,7 +660,7 @@ static inline void set_timer_irq_phys_active(struct arch_timer_context *ctx, boo
 static void kvm_timer_vcpu_load_gic(struct arch_timer_context *ctx)
 {
 	struct kvm_vcpu *vcpu = timer_context_to_vcpu(ctx);
-	bool phys_active = false;
+	bool phys_active = vgic_is_v5(vcpu->kvm);
 
 	/*
 	 * Update the timer output so that it is likely to match the
@@ -934,6 +934,12 @@ void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu)
 
 	if (kvm_vcpu_is_blocking(vcpu))
 		kvm_timer_blocking(vcpu);
+
+	if (vgic_is_v5(vcpu)) {
+		set_timer_irq_phys_active(map.direct_vtimer, false);
+		if (map.direct_ptimer)
+			set_timer_irq_phys_active(map.direct_ptimer, false);
+	}
 }
 
 void kvm_timer_sync_nested(struct kvm_vcpu *vcpu)
@@ -1333,7 +1339,8 @@ static int kvm_irq_init(struct arch_timer_kvm_info *info)
 	host_vtimer_irq = info->virtual_irq;
 	kvm_irq_fixup_flags(host_vtimer_irq, &host_vtimer_irq_flags);
 
-	if (kvm_vgic_global_state.no_hw_deactivation) {
+	if (kvm_vgic_global_state.no_hw_deactivation ||
+	    kvm_vgic_global_state.type == VGIC_V5) {
 		struct fwnode_handle *fwnode;
 		struct irq_data *data;
 
@@ -1351,7 +1358,8 @@ static int kvm_irq_init(struct arch_timer_kvm_info *info)
 			return -ENOMEM;
 		}
 
-		arch_timer_irq_ops.flags |= VGIC_IRQ_SW_RESAMPLE;
+		if (kvm_vgic_global_state.no_hw_deactivation)
+			arch_timer_irq_ops.flags |= VGIC_IRQ_SW_RESAMPLE;
 		WARN_ON(irq_domain_push_irq(domain, host_vtimer_irq,
 					    (void *)TIMER_VTIMER));
 	}

which should avoid adding some new masking stuff.

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.

Re: [PATCH v6 29/39] KVM: arm64: gic-v5: Enlighten arch timer for GICv5

[Sascha Bischoff]

On Tue, 2026-03-17 at 18:05 +0000, Marc Zyngier wrote:
> On Tue, 17 Mar 2026 11:47:29 +0000,
> Sascha Bischoff <Sascha.Bischoff@arm.com> wrote:
> > 
> > Now that GICv5 has arrived, the arch timer requires some TLC to
> > address some of the key differences introduced with GICv5.
> > 
> > For PPIs on GICv5, the queue_irq_unlock irq_op is used as AP lists
> > are
> > not required at all for GICv5. The arch timer also introduces an
> > irq_op - get_input_level. Extend the arch-timer-provided irq_ops to
> > include the PPI op for vgic_v5 guests.
> > 
> > When possible, DVI (Direct Virtual Interrupt) is set for PPIs when
> > using a vgic_v5, which directly inject the pending state into the
> > guest. This means that the host never sees the interrupt for the
> > guest
> > for these interrupts. This has three impacts.
> > 
> > * First of all, the kvm_cpu_has_pending_timer check is updated to
> >   explicitly check if the timers are expected to fire.
> > 
> > * Secondly, for mapped timers (which use DVI) they must be masked
> > on
> >   the host prior to entering a GICv5 guest, and unmasked on the
> > return
> >   path. This is handled in set_timer_irq_phys_masked.
> > 
> > * Thirdly, it makes zero sense to attempt to inject state for a
> > DVI'd
> >   interrupt. Track which timers are direct, and skip the call to
> >   kvm_vgic_inject_irq() for these.
> > 
> > The final, but rather important, change is that the architected
> > PPIs
> > for the timers are made mandatory for a GICv5 guest. Attempts to
> > set
> > them to anything else are actively rejected. Once a vgic_v5 is
> > initialised, the arch timer PPIs are also explicitly reinitialised
> > to
> > ensure the correct GICv5-compatible PPIs are used - this also adds
> > in
> > the GICv5 PPI type to the intid.
> > 
> > Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
> > Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
> > ---
> >  arch/arm64/kvm/arch_timer.c     | 110 ++++++++++++++++++++++++++--
> > ----
> >  arch/arm64/kvm/vgic/vgic-init.c |   9 +++
> >  arch/arm64/kvm/vgic/vgic-v5.c   |   7 +-
> >  include/kvm/arm_arch_timer.h    |  11 +++-
> >  include/kvm/arm_vgic.h          |   3 +
> >  5 files changed, 115 insertions(+), 25 deletions(-)
> > 
> > diff --git a/arch/arm64/kvm/arch_timer.c
> > b/arch/arm64/kvm/arch_timer.c
> > index 53312b88c342d..4575c36cae537 100644
> > --- a/arch/arm64/kvm/arch_timer.c
> > +++ b/arch/arm64/kvm/arch_timer.c
> > @@ -56,6 +56,12 @@ static struct irq_ops arch_timer_irq_ops = {
> >  	.get_input_level = kvm_arch_timer_get_input_level,
> >  };
> >  
> > +static struct irq_ops arch_timer_irq_ops_vgic_v5 = {
> > +	.get_input_level = kvm_arch_timer_get_input_level,
> > +	.queue_irq_unlock = vgic_v5_ppi_queue_irq_unlock,
> > +	.set_direct_injection = vgic_v5_set_ppi_dvi,
> > +};
> > +
> >  static int nr_timers(struct kvm_vcpu *vcpu)
> >  {
> >  	if (!vcpu_has_nv(vcpu))
> > @@ -177,6 +183,10 @@ void get_timer_map(struct kvm_vcpu *vcpu,
> > struct timer_map *map)
> >  		map->emul_ptimer = vcpu_ptimer(vcpu);
> >  	}
> >  
> > +	map->direct_vtimer->direct = true;
> > +	if (map->direct_ptimer)
> > +		map->direct_ptimer->direct = true;
> > +
> >  	trace_kvm_get_timer_map(vcpu->vcpu_id, map);
> >  }
> >  
> > @@ -396,7 +406,11 @@ static bool kvm_timer_should_fire(struct
> > arch_timer_context *timer_ctx)
> >  
> >  int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
> >  {
> > -	return vcpu_has_wfit_active(vcpu) && wfit_delay_ns(vcpu)
> > == 0;
> > +	struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
> > +	struct arch_timer_context *ptimer = vcpu_ptimer(vcpu);
> > +
> > +	return kvm_timer_should_fire(vtimer) ||
> > kvm_timer_should_fire(ptimer) ||
> > +	       (vcpu_has_wfit_active(vcpu) && wfit_delay_ns(vcpu)
> > == 0);
> >  }
> >  
> >  /*
> > @@ -447,6 +461,10 @@ static void kvm_timer_update_irq(struct
> > kvm_vcpu *vcpu, bool new_level,
> >  	if (userspace_irqchip(vcpu->kvm))
> >  		return;
> >  
> > +	/* Skip injecting on GICv5 for directly injected (DVI'd)
> > timers */
> > +	if (vgic_is_v5(vcpu->kvm) && timer_ctx->direct)
> > +		return;
> > +
> >  	kvm_vgic_inject_irq(vcpu->kvm, vcpu,
> >  			    timer_irq(timer_ctx),
> >  			    timer_ctx->irq.level,
> > @@ -657,6 +675,24 @@ static inline void
> > set_timer_irq_phys_active(struct arch_timer_context *ctx, boo
> >  	WARN_ON(r);
> >  }
> >  
> > +/*
> > + * On GICv5 we use DVI for the arch timer PPIs. This is restored
> > later
> > + * on as part of vgic_load. Therefore, in order to avoid the
> > guest's
> > + * interrupt making it to the host we mask it before entering the
> > + * guest and unmask it again when we return.
> > + */
> > +static inline void set_timer_irq_phys_masked(struct
> > arch_timer_context *ctx, bool masked)
> > +{
> > +	if (masked) {
> > +		disable_percpu_irq(ctx->host_timer_irq);
> > +	} else {
> > +		if (ctx->host_timer_irq == host_vtimer_irq)
> > +			enable_percpu_irq(ctx->host_timer_irq,
> > host_vtimer_irq_flags);
> > +		else
> > +			enable_percpu_irq(ctx->host_timer_irq,
> > host_ptimer_irq_flags);
> > +	}
> > +}
> 
> I think this is missing a trick, which is to reuse the mask/unmask
> infrastructure we use for the fruity crap. How about this following
> untested hack?
> 
> diff --git a/arch/arm64/kvm/arch_timer.c
> b/arch/arm64/kvm/arch_timer.c
> index 600f250753b45..b29bea800e2ab 100644
> --- a/arch/arm64/kvm/arch_timer.c
> +++ b/arch/arm64/kvm/arch_timer.c
> @@ -660,7 +660,7 @@ static inline void
> set_timer_irq_phys_active(struct arch_timer_context *ctx, boo
>  static void kvm_timer_vcpu_load_gic(struct arch_timer_context *ctx)
>  {
>  	struct kvm_vcpu *vcpu = timer_context_to_vcpu(ctx);
> -	bool phys_active = false;
> +	bool phys_active = vgic_is_v5(vcpu->kvm);

Note: This needs to be or'd in later as it gets overwritten by
kvm_vgic_map_is_active().

>  
>  	/*
>  	 * Update the timer output so that it is likely to match the
> @@ -934,6 +934,12 @@ void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu)
>  
>  	if (kvm_vcpu_is_blocking(vcpu))
>  		kvm_timer_blocking(vcpu);
> +
> +	if (vgic_is_v5(vcpu)) {
> +		set_timer_irq_phys_active(map.direct_vtimer, false);
> +		if (map.direct_ptimer)
> +			set_timer_irq_phys_active(map.direct_ptimer,
> false);
> +	}
>  }
>  
>  void kvm_timer_sync_nested(struct kvm_vcpu *vcpu)
> @@ -1333,7 +1339,8 @@ static int kvm_irq_init(struct
> arch_timer_kvm_info *info)
>  	host_vtimer_irq = info->virtual_irq;
>  	kvm_irq_fixup_flags(host_vtimer_irq,
> &host_vtimer_irq_flags);
>  
> -	if (kvm_vgic_global_state.no_hw_deactivation) {
> +	if (kvm_vgic_global_state.no_hw_deactivation ||
> +	    kvm_vgic_global_state.type == VGIC_V5) {
>  		struct fwnode_handle *fwnode;
>  		struct irq_data *data;
>  
> @@ -1351,7 +1358,8 @@ static int kvm_irq_init(struct
> arch_timer_kvm_info *info)
>  			return -ENOMEM;
>  		}
>  
> -		arch_timer_irq_ops.flags |= VGIC_IRQ_SW_RESAMPLE;
> +		if (kvm_vgic_global_state.no_hw_deactivation)
> +			arch_timer_irq_ops.flags |=
> VGIC_IRQ_SW_RESAMPLE;
>  		WARN_ON(irq_domain_push_irq(domain, host_vtimer_irq,
>  					    (void *)TIMER_VTIMER));
>  	}
> 
> which should avoid adding some new masking stuff.

Thanks for this, Marc. I've given it a go, and have eventually been
able to make it work. Things were, as they always are, a little more
complex.

First of all, the GICv5 irqchip driver doesn't register a
irq_set_type() handler for PPIs as those do not have a configurable
handling/trigger mode. I believe we originally had this in the
prototyping, but given that all it could do is to check that the
hardware matched whatever firmware said, it was dropped as part of
upstreaming. irq_set_type() is marked as optional in the genericirq
documentation, so this seemed like a fine thing to do. 

However, as it turns out things fall over if one layers a domain on top
of a domain that doesn't implement irq_set_type() and calls
request_percpu_irq(). Somewhere in the depths of that,
__irq_set_trigger() is called, which returns -ENOSYS if the parent
domain doesn't have irq_set_type() populated.

This means that without having a irq_set_type() in the GICv5 irqchip
driver, we bail out in kvm_timer_hyp_init() with your above change.

I'm not sure if this is a deficiency in the GICv5 irqchip driver, or if
it is one in the irqchip subsystem itself. As I said, the function is
marked as optional in the documentation (Documentation/core-
api/genericirq.rst), and this suggests to me that it isn't in the case
where one has a domain hierarchy rather than a single flat domain.

I worked around this with:

diff --git a/drivers/irqchip/irq-gic-v5.c b/drivers/irqchip/irq-gic-
v5.c
index 405a5eee847b6..6b0903be8ebfd 100644
--- a/drivers/irqchip/irq-gic-v5.c
+++ b/drivers/irqchip/irq-gic-v5.c
@@ -511,6 +511,23 @@ static bool gicv5_ppi_irq_is_level(irq_hw_number_t
hwirq)
        return !!(read_ppi_sysreg_s(hwirq, PPI_HM) & bit);
 }
 
+static int gicv5_ppi_irq_set_type(struct irq_data *d, unsigned int
type)
+{
+       /*
+        * GICv5's PPIs do not have a configurable trigger or handling
+        * mode. Check that the attempt to set a type matches what the
+        * hardware reports in the HMR, and error on a mismatch.
+        */
+
+       if (type & IRQ_TYPE_EDGE_BOTH && gicv5_ppi_irq_is_level(d-
>hwirq))
+               return -EINVAL;
+
+       if (type & IRQ_TYPE_LEVEL_MASK && !gicv5_ppi_irq_is_level(d-
>hwirq))
+               return -EINVAL;
+
+       return 0;
+}
+
 static int gicv5_ppi_irq_set_vcpu_affinity(struct irq_data *d, void
*vcpu)
 {
        if (vcpu)
@@ -526,6 +543,7 @@ static const struct irq_chip gicv5_ppi_irq_chip = {
        .irq_mask               = gicv5_ppi_irq_mask,
        .irq_unmask             = gicv5_ppi_irq_unmask,
        .irq_eoi                = gicv5_ppi_irq_eoi,
+       .irq_set_type           = gicv5_ppi_irq_set_type,
        .irq_get_irqchip_state  = gicv5_ppi_irq_get_irqchip_state,
        .irq_set_irqchip_state  = gicv5_ppi_irq_set_irqchip_state,
        .irq_set_vcpu_affinity  = gicv5_ppi_irq_set_vcpu_affinity,

It is noddy, but it "fixes" the issue when requesting an irq.

The next issue is around EOIing. When running GICv3 guests that make
use of the HW bit in the LRs and hence rely on hw deactivation on a
GICv5 host we handle this in the host irqchip driver. Specifically, we
do the following for PPIs:

static void gicv5_ppi_irq_eoi(struct irq_data *d)
{
        /* Skip deactivate for forwarded PPI interrupts */
        if (irqd_is_forwarded_to_vcpu(d)) {
                gic_insn(0, CDEOI);
                return;
        }

        gicv5_hwirq_eoi(d->hwirq, GICV5_HWIRQ_TYPE_PPI);
}

The arch_timer irqchip's EOI as it currently stands completely skips
the EOI callback for forwarded irqs. This doesn't work for GICv3 guests
on GICv5 as that means they never get EOI'd as the we emulate that in
software. Therefore, one needs to explicitly catch that case, and call
the host irqchip driver's EOI on GICv5 hosts:

 static void timer_irq_eoi(struct irq_data *d)
 {
-       if (!irqd_is_forwarded_to_vcpu(d))
+       /*
+        * On a GICv5 host, we still need to call EOI on the parent for
+        * PPIs. The host driver already handles irqs which are forwarded to
+        * vcpus, and skips the GIC CDDI while still doing the GIC CDEOI. This
+        * is required to emulate the EOIMode=1 on GICv5 hardware. Failure to
+        * call EOI unsurprisingly results in *BAD* lock-ups.
+        */
+       if (!irqd_is_forwarded_to_vcpu(d) ||
+           kvm_vgic_global_state.type == VGIC_V5)
                irq_chip_eoi_parent(d);
 }

In the end after making these changes, I've been able to get this
working for the arch_timer code, and can completely remove the bespoke
GICv5 masking.

Thanks,
Sascha

> 
> Thanks,
> 
> 	M.
> 

[PATCH v6 30/39] KVM: arm64: gic-v5: Mandate architected PPI for PMU emulation on GICv5

[Sascha Bischoff]

Make it mandatory to use the architected PPI when running a GICv5
guest. Attempts to set anything other than the architected PPI (23)
are rejected.

Additionally, KVM_ARM_VCPU_PMU_V3_INIT is relaxed to no longer require
KVM_ARM_VCPU_PMU_V3_IRQ to be called for GICv5-based guests. In this
case, the architectued PPI is automatically used.

Documentation is bumped accordingly.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
---
 Documentation/virt/kvm/devices/vcpu.rst |  5 +++--
 arch/arm64/kvm/pmu-emul.c               | 13 +++++++++++--
 include/kvm/arm_pmu.h                   |  5 ++++-
 3 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/Documentation/virt/kvm/devices/vcpu.rst b/Documentation/virt/kvm/devices/vcpu.rst
index 60bf205cb3730..5e38058200105 100644
--- a/Documentation/virt/kvm/devices/vcpu.rst
+++ b/Documentation/virt/kvm/devices/vcpu.rst
@@ -37,7 +37,8 @@ Returns:
 A value describing the PMUv3 (Performance Monitor Unit v3) overflow interrupt
 number for this vcpu. This interrupt could be a PPI or SPI, but the interrupt
 type must be same for each vcpu. As a PPI, the interrupt number is the same for
-all vcpus, while as an SPI it must be a separate number per vcpu.
+all vcpus, while as an SPI it must be a separate number per vcpu. For
+GICv5-based guests, the architected PPI (23) must be used.
 
 1.2 ATTRIBUTE: KVM_ARM_VCPU_PMU_V3_INIT
 ---------------------------------------
@@ -50,7 +51,7 @@ Returns:
 	 -EEXIST  Interrupt number already used
 	 -ENODEV  PMUv3 not supported or GIC not initialized
 	 -ENXIO   PMUv3 not supported, missing VCPU feature or interrupt
-		  number not set
+		  number not set (non-GICv5 guests, only)
 	 -EBUSY   PMUv3 already initialized
 	 =======  ======================================================
 
diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c
index 41a3c5dc2bcac..e1860acae641f 100644
--- a/arch/arm64/kvm/pmu-emul.c
+++ b/arch/arm64/kvm/pmu-emul.c
@@ -962,8 +962,13 @@ static int kvm_arm_pmu_v3_init(struct kvm_vcpu *vcpu)
 		if (!vgic_initialized(vcpu->kvm))
 			return -ENODEV;
 
-		if (!kvm_arm_pmu_irq_initialized(vcpu))
-			return -ENXIO;
+		if (!kvm_arm_pmu_irq_initialized(vcpu)) {
+			if (!vgic_is_v5(vcpu->kvm))
+				return -ENXIO;
+
+			/* Use the architected irq number for GICv5. */
+			vcpu->arch.pmu.irq_num = KVM_ARMV8_PMU_GICV5_IRQ;
+		}
 
 		ret = kvm_vgic_set_owner(vcpu, vcpu->arch.pmu.irq_num,
 					 &vcpu->arch.pmu);
@@ -988,6 +993,10 @@ static bool pmu_irq_is_valid(struct kvm *kvm, int irq)
 	unsigned long i;
 	struct kvm_vcpu *vcpu;
 
+	/* On GICv5, the PMUIRQ is architecturally mandated to be PPI 23 */
+	if (vgic_is_v5(kvm) && irq != KVM_ARMV8_PMU_GICV5_IRQ)
+		return false;
+
 	kvm_for_each_vcpu(i, vcpu, kvm) {
 		if (!kvm_arm_pmu_irq_initialized(vcpu))
 			continue;
diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h
index 96754b51b4116..0a36a3d5c8944 100644
--- a/include/kvm/arm_pmu.h
+++ b/include/kvm/arm_pmu.h
@@ -12,6 +12,9 @@
 
 #define KVM_ARMV8_PMU_MAX_COUNTERS	32
 
+/* PPI #23 - architecturally specified for GICv5 */
+#define KVM_ARMV8_PMU_GICV5_IRQ		0x20000017
+
 #if IS_ENABLED(CONFIG_HW_PERF_EVENTS) && IS_ENABLED(CONFIG_KVM)
 struct kvm_pmc {
 	u8 idx;	/* index into the pmu->pmc array */
@@ -38,7 +41,7 @@ struct arm_pmu_entry {
 };
 
 bool kvm_supports_guest_pmuv3(void);
-#define kvm_arm_pmu_irq_initialized(v)	((v)->arch.pmu.irq_num >= VGIC_NR_SGIS)
+#define kvm_arm_pmu_irq_initialized(v)	((v)->arch.pmu.irq_num != 0)
 u64 kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu, u64 select_idx);
 void kvm_pmu_set_counter_value(struct kvm_vcpu *vcpu, u64 select_idx, u64 val);
 void kvm_pmu_set_counter_value_user(struct kvm_vcpu *vcpu, u64 select_idx, u64 val);
-- 
2.34.1

[PATCH v6 31/39] KVM: arm64: gic: Hide GICv5 for protected guests

[Sascha Bischoff]

We don't support running protected guest with GICv5 at the moment.
Therefore, be sure that we don't expose it to the guest at all by
actively hiding it when running a protected guest.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
---
 arch/arm64/include/asm/kvm_hyp.h   | 1 +
 arch/arm64/kvm/arm.c               | 1 +
 arch/arm64/kvm/hyp/nvhe/sys_regs.c | 8 ++++++++
 3 files changed, 10 insertions(+)

diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h
index 2d8dfd534bd9d..5648e8d9ff625 100644
--- a/arch/arm64/include/asm/kvm_hyp.h
+++ b/arch/arm64/include/asm/kvm_hyp.h
@@ -145,6 +145,7 @@ void __noreturn __host_enter(struct kvm_cpu_context *host_ctxt);
 
 extern u64 kvm_nvhe_sym(id_aa64pfr0_el1_sys_val);
 extern u64 kvm_nvhe_sym(id_aa64pfr1_el1_sys_val);
+extern u64 kvm_nvhe_sym(id_aa64pfr2_el1_sys_val);
 extern u64 kvm_nvhe_sym(id_aa64isar0_el1_sys_val);
 extern u64 kvm_nvhe_sym(id_aa64isar1_el1_sys_val);
 extern u64 kvm_nvhe_sym(id_aa64isar2_el1_sys_val);
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 8577d7dd4d1ef..cb22bed9c85de 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -2530,6 +2530,7 @@ static void kvm_hyp_init_symbols(void)
 {
 	kvm_nvhe_sym(id_aa64pfr0_el1_sys_val) = get_hyp_id_aa64pfr0_el1();
 	kvm_nvhe_sym(id_aa64pfr1_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64PFR1_EL1);
+	kvm_nvhe_sym(id_aa64pfr2_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64PFR2_EL1);
 	kvm_nvhe_sym(id_aa64isar0_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64ISAR0_EL1);
 	kvm_nvhe_sym(id_aa64isar1_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64ISAR1_EL1);
 	kvm_nvhe_sym(id_aa64isar2_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64ISAR2_EL1);
diff --git a/arch/arm64/kvm/hyp/nvhe/sys_regs.c b/arch/arm64/kvm/hyp/nvhe/sys_regs.c
index 06d28621722ee..b40fd01ebf329 100644
--- a/arch/arm64/kvm/hyp/nvhe/sys_regs.c
+++ b/arch/arm64/kvm/hyp/nvhe/sys_regs.c
@@ -20,6 +20,7 @@
  */
 u64 id_aa64pfr0_el1_sys_val;
 u64 id_aa64pfr1_el1_sys_val;
+u64 id_aa64pfr2_el1_sys_val;
 u64 id_aa64isar0_el1_sys_val;
 u64 id_aa64isar1_el1_sys_val;
 u64 id_aa64isar2_el1_sys_val;
@@ -108,6 +109,11 @@ static const struct pvm_ftr_bits pvmid_aa64pfr1[] = {
 	FEAT_END
 };
 
+static const struct pvm_ftr_bits pvmid_aa64pfr2[] = {
+	MAX_FEAT(ID_AA64PFR2_EL1, GCIE, NI),
+	FEAT_END
+};
+
 static const struct pvm_ftr_bits pvmid_aa64mmfr0[] = {
 	MAX_FEAT_ENUM(ID_AA64MMFR0_EL1, PARANGE, 40),
 	MAX_FEAT_ENUM(ID_AA64MMFR0_EL1, ASIDBITS, 16),
@@ -221,6 +227,8 @@ static u64 pvm_calc_id_reg(const struct kvm_vcpu *vcpu, u32 id)
 		return get_restricted_features(vcpu, id_aa64pfr0_el1_sys_val, pvmid_aa64pfr0);
 	case SYS_ID_AA64PFR1_EL1:
 		return get_restricted_features(vcpu, id_aa64pfr1_el1_sys_val, pvmid_aa64pfr1);
+	case SYS_ID_AA64PFR2_EL1:
+		return get_restricted_features(vcpu, id_aa64pfr2_el1_sys_val, pvmid_aa64pfr2);
 	case SYS_ID_AA64ISAR0_EL1:
 		return id_aa64isar0_el1_sys_val;
 	case SYS_ID_AA64ISAR1_EL1:
-- 
2.34.1

[PATCH v6 32/39] KVM: arm64: gic-v5: Hide FEAT_GCIE from NV GICv5 guests

[Sascha Bischoff]

Currently, NV guests are not supported with GICv5. Therefore, make
sure that FEAT_GCIE is always hidden from such guests.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
---
 arch/arm64/kvm/nested.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c
index 2c43097248b21..efd5d21c7ac75 100644
--- a/arch/arm64/kvm/nested.c
+++ b/arch/arm64/kvm/nested.c
@@ -1558,6 +1558,11 @@ u64 limit_nv_id_reg(struct kvm *kvm, u32 reg, u64 val)
 			 ID_AA64PFR1_EL1_MTE);
 		break;
 
+	case SYS_ID_AA64PFR2_EL1:
+		/* GICv5 is not yet supported for NV */
+		val &= ~ID_AA64PFR2_EL1_GCIE;
+		break;
+
 	case SYS_ID_AA64MMFR0_EL1:
 		/* Hide ExS, Secure Memory */
 		val &= ~(ID_AA64MMFR0_EL1_EXS		|
-- 
2.34.1

[PATCH v6 33/39] KVM: arm64: gic-v5: Introduce kvm_arm_vgic_v5_ops and register them

[Sascha Bischoff]

Only the KVM_DEV_ARM_VGIC_GRP_CTRL->KVM_DEV_ARM_VGIC_CTRL_INIT op is
currently supported. All other ops are stubbed out.

Co-authored-by: Timothy Hayes <timothy.hayes@arm.com>
Signed-off-by: Timothy Hayes <timothy.hayes@arm.com>
Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
---
 arch/arm64/kvm/vgic/vgic-kvm-device.c | 74 +++++++++++++++++++++++++++
 include/linux/kvm_host.h              |  1 +
 2 files changed, 75 insertions(+)

diff --git a/arch/arm64/kvm/vgic/vgic-kvm-device.c b/arch/arm64/kvm/vgic/vgic-kvm-device.c
index b12ba99a423e5..772da54c1518b 100644
--- a/arch/arm64/kvm/vgic/vgic-kvm-device.c
+++ b/arch/arm64/kvm/vgic/vgic-kvm-device.c
@@ -336,6 +336,10 @@ int kvm_register_vgic_device(unsigned long type)
 			break;
 		ret = kvm_vgic_register_its_device();
 		break;
+	case KVM_DEV_TYPE_ARM_VGIC_V5:
+		ret = kvm_register_device_ops(&kvm_arm_vgic_v5_ops,
+					      KVM_DEV_TYPE_ARM_VGIC_V5);
+		break;
 	}
 
 	return ret;
@@ -715,3 +719,73 @@ struct kvm_device_ops kvm_arm_vgic_v3_ops = {
 	.get_attr = vgic_v3_get_attr,
 	.has_attr = vgic_v3_has_attr,
 };
+
+static int vgic_v5_set_attr(struct kvm_device *dev,
+			    struct kvm_device_attr *attr)
+{
+	switch (attr->group) {
+	case KVM_DEV_ARM_VGIC_GRP_ADDR:
+	case KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS:
+	case KVM_DEV_ARM_VGIC_GRP_NR_IRQS:
+		return -ENXIO;
+	case KVM_DEV_ARM_VGIC_GRP_CTRL:
+		switch (attr->attr) {
+		case KVM_DEV_ARM_VGIC_CTRL_INIT:
+			return vgic_set_common_attr(dev, attr);
+		default:
+			return -ENXIO;
+		}
+	default:
+		return -ENXIO;
+	}
+
+}
+
+static int vgic_v5_get_attr(struct kvm_device *dev,
+			    struct kvm_device_attr *attr)
+{
+	switch (attr->group) {
+	case KVM_DEV_ARM_VGIC_GRP_ADDR:
+	case KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS:
+	case KVM_DEV_ARM_VGIC_GRP_NR_IRQS:
+		return -ENXIO;
+	case KVM_DEV_ARM_VGIC_GRP_CTRL:
+		switch (attr->attr) {
+		case KVM_DEV_ARM_VGIC_CTRL_INIT:
+			return vgic_get_common_attr(dev, attr);
+		default:
+			return -ENXIO;
+		}
+	default:
+		return -ENXIO;
+	}
+}
+
+static int vgic_v5_has_attr(struct kvm_device *dev,
+			    struct kvm_device_attr *attr)
+{
+	switch (attr->group) {
+	case KVM_DEV_ARM_VGIC_GRP_ADDR:
+	case KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS:
+	case KVM_DEV_ARM_VGIC_GRP_NR_IRQS:
+		return -ENXIO;
+	case KVM_DEV_ARM_VGIC_GRP_CTRL:
+		switch (attr->attr) {
+		case KVM_DEV_ARM_VGIC_CTRL_INIT:
+			return 0;
+		default:
+			return -ENXIO;
+		}
+	default:
+		return -ENXIO;
+	}
+}
+
+struct kvm_device_ops kvm_arm_vgic_v5_ops = {
+	.name = "kvm-arm-vgic-v5",
+	.create = vgic_create,
+	.destroy = vgic_destroy,
+	.set_attr = vgic_v5_set_attr,
+	.get_attr = vgic_v5_get_attr,
+	.has_attr = vgic_v5_has_attr,
+};
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 6b76e7a6f4c22..779d9ed85cbfd 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -2366,6 +2366,7 @@ void kvm_unregister_device_ops(u32 type);
 extern struct kvm_device_ops kvm_mpic_ops;
 extern struct kvm_device_ops kvm_arm_vgic_v2_ops;
 extern struct kvm_device_ops kvm_arm_vgic_v3_ops;
+extern struct kvm_device_ops kvm_arm_vgic_v5_ops;
 
 #ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT
 
-- 
2.34.1

[PATCH v6 34/39] KVM: arm64: gic-v5: Set ICH_VCTLR_EL2.En on boot

[Sascha Bischoff]

This control enables virtual HPPI selection, i.e., selection and
delivery of interrupts for a guest (assuming that the guest itself has
opted to receive interrupts). This is set to enabled on boot as there
is no reason for disabling it in normal operation as virtual interrupt
signalling itself is still controlled via the HCR_EL2.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
---
 arch/arm64/include/asm/el2_setup.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm64/include/asm/el2_setup.h b/arch/arm64/include/asm/el2_setup.h
index 85f4c1615472d..998b2a3f615a7 100644
--- a/arch/arm64/include/asm/el2_setup.h
+++ b/arch/arm64/include/asm/el2_setup.h
@@ -248,6 +248,8 @@
 		     ICH_HFGWTR_EL2_ICC_CR0_EL1			| \
 		     ICH_HFGWTR_EL2_ICC_APR_EL1)
 	msr_s	SYS_ICH_HFGWTR_EL2, x0		// Disable reg write traps
+	mov	x0, #(ICH_VCTLR_EL2_En)
+	msr_s	SYS_ICH_VCTLR_EL2, x0		// Enable vHPPI selection
 .Lskip_gicv5_\@:
 .endm
 
-- 
2.34.1

[PATCH v6 35/39] KVM: arm64: gic-v5: Probe for GICv5 device

[Sascha Bischoff]

The basic GICv5 PPI support is now complete. Allow probing for a
native GICv5 rather than just the legacy support.

The implementation doesn't support protected VMs with GICv5 at this
time. Therefore, if KVM has protected mode enabled the native GICv5
init is skipped, but legacy VMs are allowed if the hardware supports
it.

At this stage the GICv5 KVM implementation only supports PPIs, and
doesn't interact with the host IRS at all. This means that there is no
need to check how many concurrent VMs or vCPUs per VM are supported by
the IRS - the PPI support only requires the CPUIF. The support is
artificially limited to VGIC_V5_MAX_CPUS, i.e. 512, vCPUs per VM.

With this change it becomes possible to run basic GICv5-based VMs,
provided that they only use PPIs.

Co-authored-by: Timothy Hayes <timothy.hayes@arm.com>
Signed-off-by: Timothy Hayes <timothy.hayes@arm.com>
Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
---
 arch/arm64/kvm/vgic/vgic-v5.c | 43 ++++++++++++++++++++++++++---------
 1 file changed, 32 insertions(+), 11 deletions(-)

diff --git a/arch/arm64/kvm/vgic/vgic-v5.c b/arch/arm64/kvm/vgic/vgic-v5.c
index 32565bfbd1051..e491ae0e4f56e 100644
--- a/arch/arm64/kvm/vgic/vgic-v5.c
+++ b/arch/arm64/kvm/vgic/vgic-v5.c
@@ -39,24 +39,13 @@ static void vgic_v5_get_implemented_ppis(void)
 
 /*
  * Probe for a vGICv5 compatible interrupt controller, returning 0 on success.
- * Currently only supports GICv3-based VMs on a GICv5 host, and hence only
- * registers a VGIC_V3 device.
  */
 int vgic_v5_probe(const struct gic_kvm_info *info)
 {
 	u64 ich_vtr_el2;
 	int ret;
 
-	vgic_v5_get_implemented_ppis();
-
-	if (!cpus_have_final_cap(ARM64_HAS_GICV5_LEGACY))
-		return -ENODEV;
-
 	kvm_vgic_global_state.type = VGIC_V5;
-	kvm_vgic_global_state.has_gcie_v3_compat = true;
-
-	/* We only support v3 compat mode - use vGICv3 limits */
-	kvm_vgic_global_state.max_gic_vcpus = VGIC_V3_MAX_CPUS;
 
 	kvm_vgic_global_state.vcpu_base = 0;
 	kvm_vgic_global_state.vctrl_base = NULL;
@@ -64,6 +53,34 @@ int vgic_v5_probe(const struct gic_kvm_info *info)
 	kvm_vgic_global_state.has_gicv4 = false;
 	kvm_vgic_global_state.has_gicv4_1 = false;
 
+	/*
+	 * GICv5 is currently not supported in Protected mode. Skip the
+	 * registration of GICv5 completely to make sure no guests can create a
+	 * GICv5-based guest.
+	 */
+	if (is_protected_kvm_enabled()) {
+		kvm_info("GICv5-based guests are not supported with pKVM\n");
+		goto skip_v5;
+	}
+
+	kvm_vgic_global_state.max_gic_vcpus = VGIC_V5_MAX_CPUS;
+
+	vgic_v5_get_implemented_ppis();
+
+	ret = kvm_register_vgic_device(KVM_DEV_TYPE_ARM_VGIC_V5);
+	if (ret) {
+		kvm_err("Cannot register GICv5 KVM device.\n");
+		goto skip_v5;
+	}
+
+	kvm_info("GCIE system register CPU interface\n");
+
+skip_v5:
+	/* If we don't support the GICv3 compat mode we're done. */
+	if (!cpus_have_final_cap(ARM64_HAS_GICV5_LEGACY))
+		return 0;
+
+	kvm_vgic_global_state.has_gcie_v3_compat = true;
 	ich_vtr_el2 =  kvm_call_hyp_ret(__vgic_v3_get_gic_config);
 	kvm_vgic_global_state.ich_vtr_el2 = (u32)ich_vtr_el2;
 
@@ -79,6 +96,10 @@ int vgic_v5_probe(const struct gic_kvm_info *info)
 		return ret;
 	}
 
+	/* We potentially limit the max VCPUs further than we need to here */
+	kvm_vgic_global_state.max_gic_vcpus = min(VGIC_V3_MAX_CPUS,
+						  VGIC_V5_MAX_CPUS);
+
 	static_branch_enable(&kvm_vgic_global_state.gicv3_cpuif);
 	kvm_info("GCIE legacy system register CPU interface\n");
 
-- 
2.34.1

Re: [PATCH v6 35/39] KVM: arm64: gic-v5: Probe for GICv5 device

[Joey Gouly]

On Tue, Mar 17, 2026 at 11:49:02AM +0000, Sascha Bischoff wrote:
> The basic GICv5 PPI support is now complete. Allow probing for a
> native GICv5 rather than just the legacy support.
> 
> The implementation doesn't support protected VMs with GICv5 at this
> time. Therefore, if KVM has protected mode enabled the native GICv5
> init is skipped, but legacy VMs are allowed if the hardware supports
> it.
> 
> At this stage the GICv5 KVM implementation only supports PPIs, and
> doesn't interact with the host IRS at all. This means that there is no
> need to check how many concurrent VMs or vCPUs per VM are supported by
> the IRS - the PPI support only requires the CPUIF. The support is
> artificially limited to VGIC_V5_MAX_CPUS, i.e. 512, vCPUs per VM.
> 
> With this change it becomes possible to run basic GICv5-based VMs,
> provided that they only use PPIs.
> 
> Co-authored-by: Timothy Hayes <timothy.hayes@arm.com>
> Signed-off-by: Timothy Hayes <timothy.hayes@arm.com>
> Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
> Reviewed-by: Joey Gouly <joey.gouly@arm.com>
> ---
>  arch/arm64/kvm/vgic/vgic-v5.c | 43 ++++++++++++++++++++++++++---------
>  1 file changed, 32 insertions(+), 11 deletions(-)
> 
> diff --git a/arch/arm64/kvm/vgic/vgic-v5.c b/arch/arm64/kvm/vgic/vgic-v5.c
> index 32565bfbd1051..e491ae0e4f56e 100644
> --- a/arch/arm64/kvm/vgic/vgic-v5.c
> +++ b/arch/arm64/kvm/vgic/vgic-v5.c
> @@ -39,24 +39,13 @@ static void vgic_v5_get_implemented_ppis(void)
>  
>  /*
>   * Probe for a vGICv5 compatible interrupt controller, returning 0 on success.
> - * Currently only supports GICv3-based VMs on a GICv5 host, and hence only
> - * registers a VGIC_V3 device.
>   */
>  int vgic_v5_probe(const struct gic_kvm_info *info)
>  {
>  	u64 ich_vtr_el2;
>  	int ret;
>  
> -	vgic_v5_get_implemented_ppis();
> -
> -	if (!cpus_have_final_cap(ARM64_HAS_GICV5_LEGACY))
> -		return -ENODEV;
> -
>  	kvm_vgic_global_state.type = VGIC_V5;
> -	kvm_vgic_global_state.has_gcie_v3_compat = true;
> -
> -	/* We only support v3 compat mode - use vGICv3 limits */
> -	kvm_vgic_global_state.max_gic_vcpus = VGIC_V3_MAX_CPUS;
>  
>  	kvm_vgic_global_state.vcpu_base = 0;
>  	kvm_vgic_global_state.vctrl_base = NULL;
> @@ -64,6 +53,34 @@ int vgic_v5_probe(const struct gic_kvm_info *info)
>  	kvm_vgic_global_state.has_gicv4 = false;
>  	kvm_vgic_global_state.has_gicv4_1 = false;
>  
> +	/*
> +	 * GICv5 is currently not supported in Protected mode. Skip the
> +	 * registration of GICv5 completely to make sure no guests can create a
> +	 * GICv5-based guest.
> +	 */
> +	if (is_protected_kvm_enabled()) {
> +		kvm_info("GICv5-based guests are not supported with pKVM\n");
> +		goto skip_v5;
> +	}
> +
> +	kvm_vgic_global_state.max_gic_vcpus = VGIC_V5_MAX_CPUS;
> +
> +	vgic_v5_get_implemented_ppis();
> +
> +	ret = kvm_register_vgic_device(KVM_DEV_TYPE_ARM_VGIC_V5);
> +	if (ret) {
> +		kvm_err("Cannot register GICv5 KVM device.\n");
> +		goto skip_v5;
> +	}
> +
> +	kvm_info("GCIE system register CPU interface\n");
> +
> +skip_v5:
> +	/* If we don't support the GICv3 compat mode we're done. */
> +	if (!cpus_have_final_cap(ARM64_HAS_GICV5_LEGACY))

If we jump to skip_v5 because we're in pKVM, but don't have
ARM64_HAS_GICV5_LEGACY, this returns 0 but should probably be -ENODEV?

Thanks,
Joey

> +		return 0;
> +
> +	kvm_vgic_global_state.has_gcie_v3_compat = true;
>  	ich_vtr_el2 =  kvm_call_hyp_ret(__vgic_v3_get_gic_config);
>  	kvm_vgic_global_state.ich_vtr_el2 = (u32)ich_vtr_el2;
>  
> @@ -79,6 +96,10 @@ int vgic_v5_probe(const struct gic_kvm_info *info)
>  		return ret;
>  	}
>  
> +	/* We potentially limit the max VCPUs further than we need to here */
> +	kvm_vgic_global_state.max_gic_vcpus = min(VGIC_V3_MAX_CPUS,
> +						  VGIC_V5_MAX_CPUS);
> +
>  	static_branch_enable(&kvm_vgic_global_state.gicv3_cpuif);
>  	kvm_info("GCIE legacy system register CPU interface\n");
>  
> -- 
> 2.34.1

Re: [PATCH v6 35/39] KVM: arm64: gic-v5: Probe for GICv5 device

[Sascha Bischoff]

On Wed, 2026-03-18 at 15:34 +0000, Joey Gouly wrote:
> On Tue, Mar 17, 2026 at 11:49:02AM +0000, Sascha Bischoff wrote:
> > The basic GICv5 PPI support is now complete. Allow probing for a
> > native GICv5 rather than just the legacy support.
> > 
> > The implementation doesn't support protected VMs with GICv5 at this
> > time. Therefore, if KVM has protected mode enabled the native GICv5
> > init is skipped, but legacy VMs are allowed if the hardware
> > supports
> > it.
> > 
> > At this stage the GICv5 KVM implementation only supports PPIs, and
> > doesn't interact with the host IRS at all. This means that there is
> > no
> > need to check how many concurrent VMs or vCPUs per VM are supported
> > by
> > the IRS - the PPI support only requires the CPUIF. The support is
> > artificially limited to VGIC_V5_MAX_CPUS, i.e. 512, vCPUs per VM.
> > 
> > With this change it becomes possible to run basic GICv5-based VMs,
> > provided that they only use PPIs.
> > 
> > Co-authored-by: Timothy Hayes <timothy.hayes@arm.com>
> > Signed-off-by: Timothy Hayes <timothy.hayes@arm.com>
> > Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
> > Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
> > Reviewed-by: Joey Gouly <joey.gouly@arm.com>
> > ---
> >  arch/arm64/kvm/vgic/vgic-v5.c | 43 ++++++++++++++++++++++++++-----
> > ----
> >  1 file changed, 32 insertions(+), 11 deletions(-)
> > 
> > diff --git a/arch/arm64/kvm/vgic/vgic-v5.c
> > b/arch/arm64/kvm/vgic/vgic-v5.c
> > index 32565bfbd1051..e491ae0e4f56e 100644
> > --- a/arch/arm64/kvm/vgic/vgic-v5.c
> > +++ b/arch/arm64/kvm/vgic/vgic-v5.c
> > @@ -39,24 +39,13 @@ static void vgic_v5_get_implemented_ppis(void)
> >  
> >  /*
> >   * Probe for a vGICv5 compatible interrupt controller, returning 0
> > on success.
> > - * Currently only supports GICv3-based VMs on a GICv5 host, and
> > hence only
> > - * registers a VGIC_V3 device.
> >   */
> >  int vgic_v5_probe(const struct gic_kvm_info *info)
> >  {
> >  	u64 ich_vtr_el2;
> >  	int ret;
> >  
> > -	vgic_v5_get_implemented_ppis();
> > -
> > -	if (!cpus_have_final_cap(ARM64_HAS_GICV5_LEGACY))
> > -		return -ENODEV;
> > -
> >  	kvm_vgic_global_state.type = VGIC_V5;
> > -	kvm_vgic_global_state.has_gcie_v3_compat = true;
> > -
> > -	/* We only support v3 compat mode - use vGICv3 limits */
> > -	kvm_vgic_global_state.max_gic_vcpus = VGIC_V3_MAX_CPUS;
> >  
> >  	kvm_vgic_global_state.vcpu_base = 0;
> >  	kvm_vgic_global_state.vctrl_base = NULL;
> > @@ -64,6 +53,34 @@ int vgic_v5_probe(const struct gic_kvm_info
> > *info)
> >  	kvm_vgic_global_state.has_gicv4 = false;
> >  	kvm_vgic_global_state.has_gicv4_1 = false;
> >  
> > +	/*
> > +	 * GICv5 is currently not supported in Protected mode.
> > Skip the
> > +	 * registration of GICv5 completely to make sure no guests
> > can create a
> > +	 * GICv5-based guest.
> > +	 */
> > +	if (is_protected_kvm_enabled()) {
> > +		kvm_info("GICv5-based guests are not supported
> > with pKVM\n");
> > +		goto skip_v5;
> > +	}
> > +
> > +	kvm_vgic_global_state.max_gic_vcpus = VGIC_V5_MAX_CPUS;
> > +
> > +	vgic_v5_get_implemented_ppis();
> > +
> > +	ret = kvm_register_vgic_device(KVM_DEV_TYPE_ARM_VGIC_V5);
> > +	if (ret) {
> > +		kvm_err("Cannot register GICv5 KVM device.\n");
> > +		goto skip_v5;
> > +	}
> > +
> > +	kvm_info("GCIE system register CPU interface\n");
> > +
> > +skip_v5:
> > +	/* If we don't support the GICv3 compat mode we're done.
> > */
> > +	if (!cpus_have_final_cap(ARM64_HAS_GICV5_LEGACY))
> 
> If we jump to skip_v5 because we're in pKVM, but don't have
> ARM64_HAS_GICV5_LEGACY, this returns 0 but should probably be -
> ENODEV?
> 
> Thanks,
> Joey

Yeah, I think you're probably right that we want to catch that case,
although by virtue of doing this it would block doing a userspace
irqchip on GICv5 hosts under pKVM or when GICv5 isn't registered for
whatever reason. I'm doubtful that this is an issue, however.

Something like this I think would solve it:

diff --git a/arch/arm64/kvm/vgic/vgic-v5.c b/arch/arm64/kvm/vgic/vgic-
v5.c
index ea2fbc6674903..0d69ed90bc4e0 100644
--- a/arch/arm64/kvm/vgic/vgic-v5.c
+++ b/arch/arm64/kvm/vgic/vgic-v5.c
@@ -42,6 +42,7 @@ static void vgic_v5_get_implemented_ppis(void)
  */
 int vgic_v5_probe(const struct gic_kvm_info *info)
 {
+       bool v5_registered = false;
        u64 ich_vtr_el2;
        int ret;
 
@@ -73,12 +74,16 @@ int vgic_v5_probe(const struct gic_kvm_info *info)
                goto skip_v5;
        }
 
+       v5_registered = true;
        kvm_info("GCIE system register CPU interface\n");
 
 skip_v5:
        /* If we don't support the GICv3 compat mode we're done. */
-       if (!cpus_have_final_cap(ARM64_HAS_GICV5_LEGACY))
+       if (!cpus_have_final_cap(ARM64_HAS_GICV5_LEGACY)) {
+               if (!v5_registered)
+                       return -ENODEV;
                return 0;
+       }
 
        kvm_vgic_global_state.has_gcie_v3_compat = true;
        ich_vtr_el2 =  kvm_call_hyp_ret(__vgic_v3_get_gic_config);

Thanks,
Sascha

> 
> > +		return 0;
> > +
> > +	kvm_vgic_global_state.has_gcie_v3_compat = true;
> >  	ich_vtr_el2 =  kvm_call_hyp_ret(__vgic_v3_get_gic_config);
> >  	kvm_vgic_global_state.ich_vtr_el2 = (u32)ich_vtr_el2;
> >  
> > @@ -79,6 +96,10 @@ int vgic_v5_probe(const struct gic_kvm_info
> > *info)
> >  		return ret;
> >  	}
> >  
> > +	/* We potentially limit the max VCPUs further than we need
> > to here */
> > +	kvm_vgic_global_state.max_gic_vcpus =
> > min(VGIC_V3_MAX_CPUS,
> > +						 
> > VGIC_V5_MAX_CPUS);
> > +
> >  	static_branch_enable(&kvm_vgic_global_state.gicv3_cpuif);
> >  	kvm_info("GCIE legacy system register CPU interface\n");
> >  
> > -- 
> > 2.34.1

[PATCH v6 36/39] Documentation: KVM: Introduce documentation for VGICv5

[Sascha Bischoff]

Now that it is possible to create a VGICv5 device, provide initial
documentation for it. At this stage, there is little to document.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
---
 .../virt/kvm/devices/arm-vgic-v5.rst          | 37 +++++++++++++++++++
 Documentation/virt/kvm/devices/index.rst      |  1 +
 2 files changed, 38 insertions(+)
 create mode 100644 Documentation/virt/kvm/devices/arm-vgic-v5.rst

diff --git a/Documentation/virt/kvm/devices/arm-vgic-v5.rst b/Documentation/virt/kvm/devices/arm-vgic-v5.rst
new file mode 100644
index 0000000000000..9904cb888277d
--- /dev/null
+++ b/Documentation/virt/kvm/devices/arm-vgic-v5.rst
@@ -0,0 +1,37 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+====================================================
+ARM Virtual Generic Interrupt Controller v5 (VGICv5)
+====================================================
+
+
+Device types supported:
+  - KVM_DEV_TYPE_ARM_VGIC_V5     ARM Generic Interrupt Controller v5.0
+
+Only one VGIC instance may be instantiated through this API.  The created VGIC
+will act as the VM interrupt controller, requiring emulated user-space devices
+to inject interrupts to the VGIC instead of directly to CPUs.
+
+Creating a guest GICv5 device requires a host GICv5 host.  The current VGICv5
+device only supports PPI interrupts.  These can either be injected from emulated
+in-kernel devices (such as the Arch Timer, or PMU), or via the KVM_IRQ_LINE
+ioctl.
+
+Groups:
+  KVM_DEV_ARM_VGIC_GRP_CTRL
+   Attributes:
+
+    KVM_DEV_ARM_VGIC_CTRL_INIT
+      request the initialization of the VGIC, no additional parameter in
+      kvm_device_attr.addr. Must be called after all VCPUs have been created.
+
+  Errors:
+
+    =======  ========================================================
+    -ENXIO   VGIC not properly configured as required prior to calling
+             this attribute
+    -ENODEV  no online VCPU
+    -ENOMEM  memory shortage when allocating vgic internal data
+    -EFAULT  Invalid guest ram access
+    -EBUSY   One or more VCPUS are running
+    =======  ========================================================
diff --git a/Documentation/virt/kvm/devices/index.rst b/Documentation/virt/kvm/devices/index.rst
index 192cda7405c84..70845aba38f45 100644
--- a/Documentation/virt/kvm/devices/index.rst
+++ b/Documentation/virt/kvm/devices/index.rst
@@ -10,6 +10,7 @@ Devices
    arm-vgic-its
    arm-vgic
    arm-vgic-v3
+   arm-vgic-v5
    mpic
    s390_flic
    vcpu
-- 
2.34.1

[PATCH v6 37/39] KVM: arm64: gic-v5: Communicate userspace-driveable PPIs via a UAPI

[Sascha Bischoff]

GICv5 systems will likely not support the full set of PPIs. The
presence of any virtual PPI is tied to the presence of the physical
PPI. Therefore, the available PPIs will be limited by the physical
host. Userspace cannot drive any PPIs that are not implemented.

Moreover, it is not desirable to expose all PPIs to the guest in the
first place, even if they are supported in hardware. Some devices,
such as the arch timer, are implemented in KVM, and hence those PPIs
shouldn't be driven by userspace, either.

Provided a new UAPI:
  KVM_DEV_ARM_VGIC_GRP_CTRL => KVM_DEV_ARM_VGIC_USERPSPACE_PPIs

This allows userspace to query which PPIs it is able to drive via
KVM_IRQ_LINE.

Additionally, introduce a check in kvm_vm_ioctl_irq_line() to reject
any PPIs not in the userspace mask.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
---
 .../virt/kvm/devices/arm-vgic-v5.rst          | 13 ++++++++
 arch/arm64/include/uapi/asm/kvm.h             |  1 +
 arch/arm64/kvm/arm.c                          | 11 ++++++-
 arch/arm64/kvm/vgic/vgic-kvm-device.c         | 31 +++++++++++++++++++
 arch/arm64/kvm/vgic/vgic-v5.c                 | 10 ++++++
 include/kvm/arm_vgic.h                        |  3 ++
 tools/arch/arm64/include/uapi/asm/kvm.h       |  1 +
 7 files changed, 69 insertions(+), 1 deletion(-)

diff --git a/Documentation/virt/kvm/devices/arm-vgic-v5.rst b/Documentation/virt/kvm/devices/arm-vgic-v5.rst
index 9904cb888277d..29335ea823fc5 100644
--- a/Documentation/virt/kvm/devices/arm-vgic-v5.rst
+++ b/Documentation/virt/kvm/devices/arm-vgic-v5.rst
@@ -25,6 +25,19 @@ Groups:
       request the initialization of the VGIC, no additional parameter in
       kvm_device_attr.addr. Must be called after all VCPUs have been created.
 
+   KVM_DEV_ARM_VGIC_USERPSPACE_PPIs
+      request the mask of userspace-drivable PPIs. Only a subset of the PPIs can
+      be directly driven from userspace with GICv5, and the returned mask
+      informs userspace of which it is allowed to drive via KVM_IRQ_LINE.
+
+      Userspace must allocate and point to __u64[2] of data in
+      kvm_device_attr.addr. When this call returns, the provided memory will be
+      populated with the userspace PPI mask. The lower __u64 contains the mask
+      for the lower 64 PPIS, with the remaining 64 being in the second __u64.
+
+      This is a read-only attribute, and cannot be set. Attempts to set it are
+      rejected.
+
   Errors:
 
     =======  ========================================================
diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
index a792a599b9d68..1c13bfa2d38aa 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -428,6 +428,7 @@ enum {
 #define   KVM_DEV_ARM_ITS_RESTORE_TABLES        2
 #define   KVM_DEV_ARM_VGIC_SAVE_PENDING_TABLES	3
 #define   KVM_DEV_ARM_ITS_CTRL_RESET		4
+#define   KVM_DEV_ARM_VGIC_USERSPACE_PPIS	5
 
 /* Device Control API on vcpu fd */
 #define KVM_ARM_VCPU_PMU_V3_CTRL	0
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index cb22bed9c85de..36410f7cd2ad3 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1449,10 +1449,11 @@ static int vcpu_interrupt_line(struct kvm_vcpu *vcpu, int number, bool level)
 int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level,
 			  bool line_status)
 {
-	u32 irq = irq_level->irq;
 	unsigned int irq_type, vcpu_id, irq_num;
 	struct kvm_vcpu *vcpu = NULL;
 	bool level = irq_level->level;
+	u32 irq = irq_level->irq;
+	unsigned long *mask;
 
 	irq_type = (irq >> KVM_ARM_IRQ_TYPE_SHIFT) & KVM_ARM_IRQ_TYPE_MASK;
 	vcpu_id = (irq >> KVM_ARM_IRQ_VCPU_SHIFT) & KVM_ARM_IRQ_VCPU_MASK;
@@ -1486,6 +1487,14 @@ int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level,
 			if (irq_num >= VGIC_V5_NR_PRIVATE_IRQS)
 				return -EINVAL;
 
+			/*
+			 * Only allow PPIs that are explicitly exposed to
+			 * usespace to be driven via KVM_IRQ_LINE
+			 */
+			mask = kvm->arch.vgic.gicv5_vm.userspace_ppis;
+			if (!test_bit(irq_num, mask))
+				return -EINVAL;
+
 			/* Build a GICv5-style IntID here */
 			irq_num = vgic_v5_make_ppi(irq_num);
 		} else if (irq_num < VGIC_NR_SGIS ||
diff --git a/arch/arm64/kvm/vgic/vgic-kvm-device.c b/arch/arm64/kvm/vgic/vgic-kvm-device.c
index 772da54c1518b..a96c77dccf353 100644
--- a/arch/arm64/kvm/vgic/vgic-kvm-device.c
+++ b/arch/arm64/kvm/vgic/vgic-kvm-device.c
@@ -720,6 +720,32 @@ struct kvm_device_ops kvm_arm_vgic_v3_ops = {
 	.has_attr = vgic_v3_has_attr,
 };
 
+static int vgic_v5_get_userspace_ppis(struct kvm_device *dev,
+				      struct kvm_device_attr *attr)
+{
+	struct vgic_v5_vm *gicv5_vm = &dev->kvm->arch.vgic.gicv5_vm;
+	u64 __user *uaddr = (u64 __user *)(long)attr->addr;
+	int ret;
+
+	guard(mutex)(&dev->kvm->arch.config_lock);
+
+	/*
+	 * We either support 64 or 128 PPIs. In the former case, we need to
+	 * return 0s for the second 64 bits as we have no storage backing those.
+	 */
+	ret = put_user(bitmap_read(gicv5_vm->userspace_ppis, 0, 64), uaddr);
+	if (ret)
+		return ret;
+	uaddr++;
+
+	if (VGIC_V5_NR_PRIVATE_IRQS == 128)
+		ret = put_user(bitmap_read(gicv5_vm->userspace_ppis, 64, 128), uaddr);
+	else
+		ret = put_user(0, uaddr);
+
+	return ret;
+}
+
 static int vgic_v5_set_attr(struct kvm_device *dev,
 			    struct kvm_device_attr *attr)
 {
@@ -732,6 +758,7 @@ static int vgic_v5_set_attr(struct kvm_device *dev,
 		switch (attr->attr) {
 		case KVM_DEV_ARM_VGIC_CTRL_INIT:
 			return vgic_set_common_attr(dev, attr);
+		case KVM_DEV_ARM_VGIC_USERSPACE_PPIS:
 		default:
 			return -ENXIO;
 		}
@@ -753,6 +780,8 @@ static int vgic_v5_get_attr(struct kvm_device *dev,
 		switch (attr->attr) {
 		case KVM_DEV_ARM_VGIC_CTRL_INIT:
 			return vgic_get_common_attr(dev, attr);
+		case KVM_DEV_ARM_VGIC_USERSPACE_PPIS:
+			return vgic_v5_get_userspace_ppis(dev, attr);
 		default:
 			return -ENXIO;
 		}
@@ -773,6 +802,8 @@ static int vgic_v5_has_attr(struct kvm_device *dev,
 		switch (attr->attr) {
 		case KVM_DEV_ARM_VGIC_CTRL_INIT:
 			return 0;
+		case KVM_DEV_ARM_VGIC_USERSPACE_PPIS:
+			return 0;
 		default:
 			return -ENXIO;
 		}
diff --git a/arch/arm64/kvm/vgic/vgic-v5.c b/arch/arm64/kvm/vgic/vgic-v5.c
index e491ae0e4f56e..4581e51dc6e44 100644
--- a/arch/arm64/kvm/vgic/vgic-v5.c
+++ b/arch/arm64/kvm/vgic/vgic-v5.c
@@ -138,6 +138,16 @@ int vgic_v5_init(struct kvm *kvm)
 		}
 	}
 
+	/* We only allow userspace to drive the SW_PPI, if it is implemented. */
+	bitmap_zero(kvm->arch.vgic.gicv5_vm.userspace_ppis,
+		    VGIC_V5_NR_PRIVATE_IRQS);
+	__assign_bit(GICV5_ARCH_PPI_SW_PPI,
+		     kvm->arch.vgic.gicv5_vm.userspace_ppis,
+		     VGIC_V5_NR_PRIVATE_IRQS);
+	bitmap_and(kvm->arch.vgic.gicv5_vm.userspace_ppis,
+		   kvm->arch.vgic.gicv5_vm.userspace_ppis,
+		   ppi_caps.impl_ppi_mask, VGIC_V5_NR_PRIVATE_IRQS);
+
 	return 0;
 }
 
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 8cc3a7b4d8152..1388dc6028a9a 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -350,6 +350,9 @@ struct vgic_v5_vm {
 	 */
 	DECLARE_BITMAP(vgic_ppi_mask, VGIC_V5_NR_PRIVATE_IRQS);
 
+	/* A mask of the PPIs that are exposed for userspace to drive. */
+	DECLARE_BITMAP(userspace_ppis, VGIC_V5_NR_PRIVATE_IRQS);
+
 	/*
 	 * The HMR itself is handled by the hardware, but we still need to have
 	 * a mask that we can use when merging in pending state (only the state
diff --git a/tools/arch/arm64/include/uapi/asm/kvm.h b/tools/arch/arm64/include/uapi/asm/kvm.h
index a792a599b9d68..1c13bfa2d38aa 100644
--- a/tools/arch/arm64/include/uapi/asm/kvm.h
+++ b/tools/arch/arm64/include/uapi/asm/kvm.h
@@ -428,6 +428,7 @@ enum {
 #define   KVM_DEV_ARM_ITS_RESTORE_TABLES        2
 #define   KVM_DEV_ARM_VGIC_SAVE_PENDING_TABLES	3
 #define   KVM_DEV_ARM_ITS_CTRL_RESET		4
+#define   KVM_DEV_ARM_VGIC_USERSPACE_PPIS	5
 
 /* Device Control API on vcpu fd */
 #define KVM_ARM_VCPU_PMU_V3_CTRL	0
-- 
2.34.1

[PATCH v6 38/39] KVM: arm64: selftests: Introduce a minimal GICv5 PPI selftest

[Sascha Bischoff]

This basic selftest creates a vgic_v5 device (if supported), and tests
that one of the PPI interrupts works as expected with a basic
single-vCPU guest.

Upon starting, the guest enables interrupts. That means that it is
initialising all PPIs to have reasonable priorities, but marking them
as disabled. Then the priority mask in the ICC_PCR_EL1 is set, and
interrupts are enable in ICC_CR0_EL1. At this stage the guest is able
to receive interrupts. The architected SW_PPI (64) is enabled and
KVM_IRQ_LINE ioctl is used to inject the state into the guest.

The guest's interrupt handler has an explicit WFI in order to ensure
that the guest skips WFI when there are pending and enabled PPI
interrupts.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
---
 tools/testing/selftests/kvm/Makefile.kvm      |   1 +
 tools/testing/selftests/kvm/arm64/vgic_v5.c   | 228 ++++++++++++++++++
 .../selftests/kvm/include/arm64/gic_v5.h      | 150 ++++++++++++
 3 files changed, 379 insertions(+)
 create mode 100644 tools/testing/selftests/kvm/arm64/vgic_v5.c
 create mode 100644 tools/testing/selftests/kvm/include/arm64/gic_v5.h

diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm
index dc68371f76a33..98282acd90407 100644
--- a/tools/testing/selftests/kvm/Makefile.kvm
+++ b/tools/testing/selftests/kvm/Makefile.kvm
@@ -177,6 +177,7 @@ TEST_GEN_PROGS_arm64 += arm64/vcpu_width_config
 TEST_GEN_PROGS_arm64 += arm64/vgic_init
 TEST_GEN_PROGS_arm64 += arm64/vgic_irq
 TEST_GEN_PROGS_arm64 += arm64/vgic_lpi_stress
+TEST_GEN_PROGS_arm64 += arm64/vgic_v5
 TEST_GEN_PROGS_arm64 += arm64/vpmu_counter_access
 TEST_GEN_PROGS_arm64 += arm64/no-vgic-v3
 TEST_GEN_PROGS_arm64 += arm64/idreg-idst
diff --git a/tools/testing/selftests/kvm/arm64/vgic_v5.c b/tools/testing/selftests/kvm/arm64/vgic_v5.c
new file mode 100644
index 0000000000000..3ce6cf37a629f
--- /dev/null
+++ b/tools/testing/selftests/kvm/arm64/vgic_v5.c
@@ -0,0 +1,228 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/kernel.h>
+#include <sys/syscall.h>
+#include <asm/kvm.h>
+#include <asm/kvm_para.h>
+
+#include <arm64/gic_v5.h>
+
+#include "test_util.h"
+#include "kvm_util.h"
+#include "processor.h"
+#include "vgic.h"
+
+#define NR_VCPUS		1
+
+struct vm_gic {
+	struct kvm_vm *vm;
+	int gic_fd;
+	uint32_t gic_dev_type;
+};
+
+static uint64_t max_phys_size;
+
+#define GUEST_CMD_IRQ_CDIA	10
+#define GUEST_CMD_IRQ_DIEOI	11
+#define GUEST_CMD_IS_AWAKE	12
+#define GUEST_CMD_IS_READY	13
+
+static void guest_irq_handler(struct ex_regs *regs)
+{
+	bool valid;
+	u32 hwirq;
+	u64 ia;
+	static int count;
+
+	/*
+	 * We have pending interrupts. Should never actually enter WFI
+	 * here!
+	 */
+	wfi();
+	GUEST_SYNC(GUEST_CMD_IS_AWAKE);
+
+	ia = gicr_insn(CDIA);
+	valid = GICV5_GICR_CDIA_VALID(ia);
+
+	GUEST_SYNC(GUEST_CMD_IRQ_CDIA);
+
+	if (!valid)
+		return;
+
+	gsb_ack();
+	isb();
+
+	hwirq = FIELD_GET(GICV5_GICR_CDIA_INTID, ia);
+
+	gic_insn(hwirq, CDDI);
+	gic_insn(0, CDEOI);
+
+	GUEST_SYNC(GUEST_CMD_IRQ_DIEOI);
+
+	if (++count >= 2)
+		GUEST_DONE();
+
+	/* Ask for the next interrupt to be injected */
+	GUEST_SYNC(GUEST_CMD_IS_READY);
+}
+
+static void guest_code(void)
+{
+	local_irq_disable();
+
+	gicv5_cpu_enable_interrupts();
+	local_irq_enable();
+
+	/* Enable the SW_PPI (3) */
+	write_sysreg_s(BIT_ULL(3), SYS_ICC_PPI_ENABLER0_EL1);
+
+	/* Ask for the first interrupt to be injected */
+	GUEST_SYNC(GUEST_CMD_IS_READY);
+
+	/* Loop forever waiting for interrupts */
+	while (1);
+}
+
+
+/* we don't want to assert on run execution, hence that helper */
+static int run_vcpu(struct kvm_vcpu *vcpu)
+{
+	return __vcpu_run(vcpu) ? -errno : 0;
+}
+
+static void vm_gic_destroy(struct vm_gic *v)
+{
+	close(v->gic_fd);
+	kvm_vm_free(v->vm);
+}
+
+static void test_vgic_v5_ppis(uint32_t gic_dev_type)
+{
+	struct kvm_vcpu *vcpus[NR_VCPUS];
+	struct ucall uc;
+	u64 user_ppis[2];
+	struct vm_gic v;
+	int ret, i;
+
+	v.gic_dev_type = gic_dev_type;
+	v.vm = __vm_create(VM_SHAPE_DEFAULT, NR_VCPUS, 0);
+
+	v.gic_fd = kvm_create_device(v.vm, gic_dev_type);
+
+	for (i = 0; i < NR_VCPUS; i++)
+		vcpus[i] = vm_vcpu_add(v.vm, i, guest_code);
+
+	vm_init_descriptor_tables(v.vm);
+	vm_install_exception_handler(v.vm, VECTOR_IRQ_CURRENT, guest_irq_handler);
+
+	for (i = 0; i < NR_VCPUS; i++)
+		vcpu_init_descriptor_tables(vcpus[i]);
+
+	kvm_device_attr_set(v.gic_fd, KVM_DEV_ARM_VGIC_GRP_CTRL,
+			    KVM_DEV_ARM_VGIC_CTRL_INIT, NULL);
+
+	/* Read out the PPIs that user space is allowed to drive. */
+	kvm_device_attr_get(v.gic_fd, KVM_DEV_ARM_VGIC_GRP_CTRL,
+			    KVM_DEV_ARM_VGIC_USERSPACE_PPIS, &user_ppis);
+
+	/* We should always be able to drive the SW_PPI. */
+	TEST_ASSERT(user_ppis[0] & BIT(GICV5_ARCH_PPI_SW_PPI),
+		"SW_PPI is not drivable by userspace");
+
+	while (1) {
+		ret = run_vcpu(vcpus[0]);
+
+		switch (get_ucall(vcpus[0], &uc)) {
+		case UCALL_SYNC:
+			/*
+			 * The guest is ready for the next level change. Set
+			 * high if ready, and lower if it has been consumed.
+			 */
+			if (uc.args[1] == GUEST_CMD_IS_READY ||
+			    uc.args[1] == GUEST_CMD_IRQ_DIEOI) {
+				u64 irq;
+				bool level = uc.args[1] == GUEST_CMD_IRQ_DIEOI ? 0 : 1;
+
+				irq = FIELD_PREP(KVM_ARM_IRQ_NUM_MASK, 3);
+				irq |= KVM_ARM_IRQ_TYPE_PPI << KVM_ARM_IRQ_TYPE_SHIFT;
+
+				_kvm_irq_line(v.vm, irq, level);
+			} else if (uc.args[1] == GUEST_CMD_IS_AWAKE) {
+				pr_info("Guest skipping WFI due to pending IRQ\n");
+			} else if (uc.args[1] == GUEST_CMD_IRQ_CDIA) {
+				pr_info("Guest acknowledged IRQ\n");
+			}
+
+			continue;
+		case UCALL_ABORT:
+			REPORT_GUEST_ASSERT(uc);
+			break;
+		case UCALL_DONE:
+			goto done;
+		default:
+			TEST_FAIL("Unknown ucall %lu", uc.cmd);
+		}
+	}
+
+done:
+	TEST_ASSERT(ret == 0, "Failed to test GICv5 PPIs");
+
+	vm_gic_destroy(&v);
+}
+
+/*
+ * Returns 0 if it's possible to create GIC device of a given type (V5).
+ */
+int test_kvm_device(uint32_t gic_dev_type)
+{
+	struct kvm_vcpu *vcpus[NR_VCPUS];
+	struct vm_gic v;
+	int ret;
+
+	v.vm = vm_create_with_vcpus(NR_VCPUS, guest_code, vcpus);
+
+	/* try to create a non existing KVM device */
+	ret = __kvm_test_create_device(v.vm, 0);
+	TEST_ASSERT(ret && errno == ENODEV, "unsupported device");
+
+	/* trial mode */
+	ret = __kvm_test_create_device(v.vm, gic_dev_type);
+	if (ret)
+		return ret;
+	v.gic_fd = kvm_create_device(v.vm, gic_dev_type);
+
+	ret = __kvm_create_device(v.vm, gic_dev_type);
+	TEST_ASSERT(ret < 0 && errno == EEXIST, "create GIC device twice");
+
+	vm_gic_destroy(&v);
+
+	return 0;
+}
+
+void run_tests(uint32_t gic_dev_type)
+{
+	pr_info("Test VGICv5 PPIs\n");
+	test_vgic_v5_ppis(gic_dev_type);
+}
+
+int main(int ac, char **av)
+{
+	int ret;
+	int pa_bits;
+
+	test_disable_default_vgic();
+
+	pa_bits = vm_guest_mode_params[VM_MODE_DEFAULT].pa_bits;
+	max_phys_size = 1ULL << pa_bits;
+
+	ret = test_kvm_device(KVM_DEV_TYPE_ARM_VGIC_V5);
+	if (ret) {
+		pr_info("No GICv5 support; Not running GIC_v5 tests.\n");
+		exit(KSFT_SKIP);
+	}
+
+	pr_info("Running VGIC_V5 tests.\n");
+	run_tests(KVM_DEV_TYPE_ARM_VGIC_V5);
+
+	return 0;
+}
diff --git a/tools/testing/selftests/kvm/include/arm64/gic_v5.h b/tools/testing/selftests/kvm/include/arm64/gic_v5.h
new file mode 100644
index 0000000000000..eb523d9277cf1
--- /dev/null
+++ b/tools/testing/selftests/kvm/include/arm64/gic_v5.h
@@ -0,0 +1,150 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __SELFTESTS_GIC_V5_H
+#define __SELFTESTS_GIC_V5_H
+
+#include <asm/barrier.h>
+#include <asm/sysreg.h>
+
+#include <linux/bitfield.h>
+
+#include "processor.h"
+
+/*
+ * Definitions for GICv5 instructions for the Current Domain
+ */
+#define GICV5_OP_GIC_CDAFF		sys_insn(1, 0, 12, 1, 3)
+#define GICV5_OP_GIC_CDDI		sys_insn(1, 0, 12, 2, 0)
+#define GICV5_OP_GIC_CDDIS		sys_insn(1, 0, 12, 1, 0)
+#define GICV5_OP_GIC_CDHM		sys_insn(1, 0, 12, 2, 1)
+#define GICV5_OP_GIC_CDEN		sys_insn(1, 0, 12, 1, 1)
+#define GICV5_OP_GIC_CDEOI		sys_insn(1, 0, 12, 1, 7)
+#define GICV5_OP_GIC_CDPEND		sys_insn(1, 0, 12, 1, 4)
+#define GICV5_OP_GIC_CDPRI		sys_insn(1, 0, 12, 1, 2)
+#define GICV5_OP_GIC_CDRCFG		sys_insn(1, 0, 12, 1, 5)
+#define GICV5_OP_GICR_CDIA		sys_insn(1, 0, 12, 3, 0)
+#define GICV5_OP_GICR_CDNMIA		sys_insn(1, 0, 12, 3, 1)
+
+/* Definitions for GIC CDAFF */
+#define GICV5_GIC_CDAFF_IAFFID_MASK	GENMASK_ULL(47, 32)
+#define GICV5_GIC_CDAFF_TYPE_MASK	GENMASK_ULL(31, 29)
+#define GICV5_GIC_CDAFF_IRM_MASK	BIT_ULL(28)
+#define GICV5_GIC_CDAFF_ID_MASK		GENMASK_ULL(23, 0)
+
+/* Definitions for GIC CDDI */
+#define GICV5_GIC_CDDI_TYPE_MASK	GENMASK_ULL(31, 29)
+#define GICV5_GIC_CDDI_ID_MASK		GENMASK_ULL(23, 0)
+
+/* Definitions for GIC CDDIS */
+#define GICV5_GIC_CDDIS_TYPE_MASK	GENMASK_ULL(31, 29)
+#define GICV5_GIC_CDDIS_TYPE(r)		FIELD_GET(GICV5_GIC_CDDIS_TYPE_MASK, r)
+#define GICV5_GIC_CDDIS_ID_MASK		GENMASK_ULL(23, 0)
+#define GICV5_GIC_CDDIS_ID(r)		FIELD_GET(GICV5_GIC_CDDIS_ID_MASK, r)
+
+/* Definitions for GIC CDEN */
+#define GICV5_GIC_CDEN_TYPE_MASK	GENMASK_ULL(31, 29)
+#define GICV5_GIC_CDEN_ID_MASK		GENMASK_ULL(23, 0)
+
+/* Definitions for GIC CDHM */
+#define GICV5_GIC_CDHM_HM_MASK		BIT_ULL(32)
+#define GICV5_GIC_CDHM_TYPE_MASK	GENMASK_ULL(31, 29)
+#define GICV5_GIC_CDHM_ID_MASK		GENMASK_ULL(23, 0)
+
+/* Definitions for GIC CDPEND */
+#define GICV5_GIC_CDPEND_PENDING_MASK	BIT_ULL(32)
+#define GICV5_GIC_CDPEND_TYPE_MASK	GENMASK_ULL(31, 29)
+#define GICV5_GIC_CDPEND_ID_MASK	GENMASK_ULL(23, 0)
+
+/* Definitions for GIC CDPRI */
+#define GICV5_GIC_CDPRI_PRIORITY_MASK	GENMASK_ULL(39, 35)
+#define GICV5_GIC_CDPRI_TYPE_MASK	GENMASK_ULL(31, 29)
+#define GICV5_GIC_CDPRI_ID_MASK		GENMASK_ULL(23, 0)
+
+/* Definitions for GIC CDRCFG */
+#define GICV5_GIC_CDRCFG_TYPE_MASK	GENMASK_ULL(31, 29)
+#define GICV5_GIC_CDRCFG_ID_MASK	GENMASK_ULL(23, 0)
+
+/* Definitions for GICR CDIA */
+#define GICV5_GICR_CDIA_VALID_MASK	BIT_ULL(32)
+#define GICV5_GICR_CDIA_VALID(r)	FIELD_GET(GICV5_GICR_CDIA_VALID_MASK, r)
+#define GICV5_GICR_CDIA_TYPE_MASK	GENMASK_ULL(31, 29)
+#define GICV5_GICR_CDIA_ID_MASK		GENMASK_ULL(23, 0)
+#define GICV5_GICR_CDIA_INTID		GENMASK_ULL(31, 0)
+
+/* Definitions for GICR CDNMIA */
+#define GICV5_GICR_CDNMIA_VALID_MASK	BIT_ULL(32)
+#define GICV5_GICR_CDNMIA_VALID(r)	FIELD_GET(GICV5_GICR_CDNMIA_VALID_MASK, r)
+#define GICV5_GICR_CDNMIA_TYPE_MASK	GENMASK_ULL(31, 29)
+#define GICV5_GICR_CDNMIA_ID_MASK	GENMASK_ULL(23, 0)
+
+#define gicr_insn(insn)			read_sysreg_s(GICV5_OP_GICR_##insn)
+#define gic_insn(v, insn)		write_sysreg_s(v, GICV5_OP_GIC_##insn)
+
+#define __GIC_BARRIER_INSN(op0, op1, CRn, CRm, op2, Rt)			\
+	__emit_inst(0xd5000000					|	\
+		    sys_insn((op0), (op1), (CRn), (CRm), (op2))	|	\
+		    ((Rt) & 0x1f))
+
+#define GSB_SYS_BARRIER_INSN		__GIC_BARRIER_INSN(1, 0, 12, 0, 0, 31)
+#define GSB_ACK_BARRIER_INSN		__GIC_BARRIER_INSN(1, 0, 12, 0, 1, 31)
+
+#define gsb_ack()	asm volatile(GSB_ACK_BARRIER_INSN : : : "memory")
+#define gsb_sys()	asm volatile(GSB_SYS_BARRIER_INSN : : : "memory")
+
+#define REPEAT_BYTE(x)	((~0ul / 0xff) * (x))
+
+#define GICV5_IRQ_DEFAULT_PRI 0b10000
+
+#define GICV5_ARCH_PPI_SW_PPI		0x3
+
+void gicv5_ppi_priority_init(void)
+{
+	write_sysreg_s(REPEAT_BYTE(GICV5_IRQ_DEFAULT_PRI), SYS_ICC_PPI_PRIORITYR0_EL1);
+	write_sysreg_s(REPEAT_BYTE(GICV5_IRQ_DEFAULT_PRI), SYS_ICC_PPI_PRIORITYR1_EL1);
+	write_sysreg_s(REPEAT_BYTE(GICV5_IRQ_DEFAULT_PRI), SYS_ICC_PPI_PRIORITYR2_EL1);
+	write_sysreg_s(REPEAT_BYTE(GICV5_IRQ_DEFAULT_PRI), SYS_ICC_PPI_PRIORITYR3_EL1);
+	write_sysreg_s(REPEAT_BYTE(GICV5_IRQ_DEFAULT_PRI), SYS_ICC_PPI_PRIORITYR4_EL1);
+	write_sysreg_s(REPEAT_BYTE(GICV5_IRQ_DEFAULT_PRI), SYS_ICC_PPI_PRIORITYR5_EL1);
+	write_sysreg_s(REPEAT_BYTE(GICV5_IRQ_DEFAULT_PRI), SYS_ICC_PPI_PRIORITYR6_EL1);
+	write_sysreg_s(REPEAT_BYTE(GICV5_IRQ_DEFAULT_PRI), SYS_ICC_PPI_PRIORITYR7_EL1);
+	write_sysreg_s(REPEAT_BYTE(GICV5_IRQ_DEFAULT_PRI), SYS_ICC_PPI_PRIORITYR8_EL1);
+	write_sysreg_s(REPEAT_BYTE(GICV5_IRQ_DEFAULT_PRI), SYS_ICC_PPI_PRIORITYR9_EL1);
+	write_sysreg_s(REPEAT_BYTE(GICV5_IRQ_DEFAULT_PRI), SYS_ICC_PPI_PRIORITYR10_EL1);
+	write_sysreg_s(REPEAT_BYTE(GICV5_IRQ_DEFAULT_PRI), SYS_ICC_PPI_PRIORITYR11_EL1);
+	write_sysreg_s(REPEAT_BYTE(GICV5_IRQ_DEFAULT_PRI), SYS_ICC_PPI_PRIORITYR12_EL1);
+	write_sysreg_s(REPEAT_BYTE(GICV5_IRQ_DEFAULT_PRI), SYS_ICC_PPI_PRIORITYR13_EL1);
+	write_sysreg_s(REPEAT_BYTE(GICV5_IRQ_DEFAULT_PRI), SYS_ICC_PPI_PRIORITYR14_EL1);
+	write_sysreg_s(REPEAT_BYTE(GICV5_IRQ_DEFAULT_PRI), SYS_ICC_PPI_PRIORITYR15_EL1);
+
+	/*
+	 * Context syncronization required to make sure system register writes
+	 * effects are synchronised.
+	 */
+	isb();
+}
+
+void gicv5_cpu_disable_interrupts(void)
+{
+	u64 cr0;
+
+	cr0 = FIELD_PREP(ICC_CR0_EL1_EN, 0);
+	write_sysreg_s(cr0, SYS_ICC_CR0_EL1);
+}
+
+void gicv5_cpu_enable_interrupts(void)
+{
+	u64 cr0, pcr;
+
+	write_sysreg_s(0, SYS_ICC_PPI_ENABLER0_EL1);
+	write_sysreg_s(0, SYS_ICC_PPI_ENABLER1_EL1);
+
+	gicv5_ppi_priority_init();
+
+	pcr = FIELD_PREP(ICC_PCR_EL1_PRIORITY, GICV5_IRQ_DEFAULT_PRI);
+	write_sysreg_s(pcr, SYS_ICC_PCR_EL1);
+
+	cr0 = FIELD_PREP(ICC_CR0_EL1_EN, 1);
+	write_sysreg_s(cr0, SYS_ICC_CR0_EL1);
+}
+
+#endif
-- 
2.34.1

[PATCH v6 39/39] KVM: arm64: selftests: Add no-vgic-v5 selftest

[Sascha Bischoff]

Now that GICv5 is supported, it is important to check that all of the
GICv5 register state is hidden from a guest that doesn't create a
vGICv5.

Rename the no-vgic-v3 selftest to no-vgic, and extend it to check
GICv5 system registers too.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
---
 tools/testing/selftests/kvm/Makefile.kvm      |   2 +-
 .../testing/selftests/kvm/arm64/no-vgic-v3.c  | 177 -----------
 tools/testing/selftests/kvm/arm64/no-vgic.c   | 297 ++++++++++++++++++
 3 files changed, 298 insertions(+), 178 deletions(-)
 delete mode 100644 tools/testing/selftests/kvm/arm64/no-vgic-v3.c
 create mode 100644 tools/testing/selftests/kvm/arm64/no-vgic.c

diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm
index 98282acd90407..98da9fa4b8b70 100644
--- a/tools/testing/selftests/kvm/Makefile.kvm
+++ b/tools/testing/selftests/kvm/Makefile.kvm
@@ -179,7 +179,7 @@ TEST_GEN_PROGS_arm64 += arm64/vgic_irq
 TEST_GEN_PROGS_arm64 += arm64/vgic_lpi_stress
 TEST_GEN_PROGS_arm64 += arm64/vgic_v5
 TEST_GEN_PROGS_arm64 += arm64/vpmu_counter_access
-TEST_GEN_PROGS_arm64 += arm64/no-vgic-v3
+TEST_GEN_PROGS_arm64 += arm64/no-vgic
 TEST_GEN_PROGS_arm64 += arm64/idreg-idst
 TEST_GEN_PROGS_arm64 += arm64/kvm-uuid
 TEST_GEN_PROGS_arm64 += access_tracking_perf_test
diff --git a/tools/testing/selftests/kvm/arm64/no-vgic-v3.c b/tools/testing/selftests/kvm/arm64/no-vgic-v3.c
deleted file mode 100644
index 152c34776981a..0000000000000
--- a/tools/testing/selftests/kvm/arm64/no-vgic-v3.c
+++ /dev/null
@@ -1,177 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-
-// Check that, on a GICv3 system, not configuring GICv3 correctly
-// results in all of the sysregs generating an UNDEF exception.
-
-#include <test_util.h>
-#include <kvm_util.h>
-#include <processor.h>
-
-static volatile bool handled;
-
-#define __check_sr_read(r)					\
-	({							\
-		uint64_t val;					\
-								\
-		handled = false;				\
-		dsb(sy);					\
-		val = read_sysreg_s(SYS_ ## r);			\
-		val;						\
-	})
-
-#define __check_sr_write(r)					\
-	do {							\
-		handled = false;				\
-		dsb(sy);					\
-		write_sysreg_s(0, SYS_ ## r);			\
-		isb();						\
-	} while(0)
-
-/* Fatal checks */
-#define check_sr_read(r)					\
-	do {							\
-		__check_sr_read(r);				\
-		__GUEST_ASSERT(handled, #r " no read trap");	\
-	} while(0)
-
-#define check_sr_write(r)					\
-	do {							\
-		__check_sr_write(r);				\
-		__GUEST_ASSERT(handled, #r " no write trap");	\
-	} while(0)
-
-#define check_sr_rw(r)				\
-	do {					\
-		check_sr_read(r);		\
-		check_sr_write(r);		\
-	} while(0)
-
-static void guest_code(void)
-{
-	uint64_t val;
-
-	/*
-	 * Check that we advertise that ID_AA64PFR0_EL1.GIC == 0, having
-	 * hidden the feature at runtime without any other userspace action.
-	 */
-	__GUEST_ASSERT(FIELD_GET(ID_AA64PFR0_EL1_GIC,
-				 read_sysreg(id_aa64pfr0_el1)) == 0,
-		       "GICv3 wrongly advertised");
-
-	/*
-	 * Access all GICv3 registers, and fail if we don't get an UNDEF.
-	 * Note that we happily access all the APxRn registers without
-	 * checking their existance, as all we want to see is a failure.
-	 */
-	check_sr_rw(ICC_PMR_EL1);
-	check_sr_read(ICC_IAR0_EL1);
-	check_sr_write(ICC_EOIR0_EL1);
-	check_sr_rw(ICC_HPPIR0_EL1);
-	check_sr_rw(ICC_BPR0_EL1);
-	check_sr_rw(ICC_AP0R0_EL1);
-	check_sr_rw(ICC_AP0R1_EL1);
-	check_sr_rw(ICC_AP0R2_EL1);
-	check_sr_rw(ICC_AP0R3_EL1);
-	check_sr_rw(ICC_AP1R0_EL1);
-	check_sr_rw(ICC_AP1R1_EL1);
-	check_sr_rw(ICC_AP1R2_EL1);
-	check_sr_rw(ICC_AP1R3_EL1);
-	check_sr_write(ICC_DIR_EL1);
-	check_sr_read(ICC_RPR_EL1);
-	check_sr_write(ICC_SGI1R_EL1);
-	check_sr_write(ICC_ASGI1R_EL1);
-	check_sr_write(ICC_SGI0R_EL1);
-	check_sr_read(ICC_IAR1_EL1);
-	check_sr_write(ICC_EOIR1_EL1);
-	check_sr_rw(ICC_HPPIR1_EL1);
-	check_sr_rw(ICC_BPR1_EL1);
-	check_sr_rw(ICC_CTLR_EL1);
-	check_sr_rw(ICC_IGRPEN0_EL1);
-	check_sr_rw(ICC_IGRPEN1_EL1);
-
-	/*
-	 * ICC_SRE_EL1 may not be trappable, as ICC_SRE_EL2.Enable can
-	 * be RAO/WI. Engage in non-fatal accesses, starting with a
-	 * write of 0 to try and disable SRE, and let's see if it
-	 * sticks.
-	 */
-	__check_sr_write(ICC_SRE_EL1);
-	if (!handled)
-		GUEST_PRINTF("ICC_SRE_EL1 write not trapping (OK)\n");
-
-	val = __check_sr_read(ICC_SRE_EL1);
-	if (!handled) {
-		__GUEST_ASSERT((val & BIT(0)),
-			       "ICC_SRE_EL1 not trapped but ICC_SRE_EL1.SRE not set\n");
-		GUEST_PRINTF("ICC_SRE_EL1 read not trapping (OK)\n");
-	}
-
-	GUEST_DONE();
-}
-
-static void guest_undef_handler(struct ex_regs *regs)
-{
-	/* Success, we've gracefully exploded! */
-	handled = true;
-	regs->pc += 4;
-}
-
-static void test_run_vcpu(struct kvm_vcpu *vcpu)
-{
-	struct ucall uc;
-
-	do {
-		vcpu_run(vcpu);
-
-		switch (get_ucall(vcpu, &uc)) {
-		case UCALL_ABORT:
-			REPORT_GUEST_ASSERT(uc);
-			break;
-		case UCALL_PRINTF:
-			printf("%s", uc.buffer);
-			break;
-		case UCALL_DONE:
-			break;
-		default:
-			TEST_FAIL("Unknown ucall %lu", uc.cmd);
-		}
-	} while (uc.cmd != UCALL_DONE);
-}
-
-static void test_guest_no_gicv3(void)
-{
-	struct kvm_vcpu *vcpu;
-	struct kvm_vm *vm;
-
-	/* Create a VM without a GICv3 */
-	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
-
-	vm_init_descriptor_tables(vm);
-	vcpu_init_descriptor_tables(vcpu);
-
-	vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT,
-				ESR_ELx_EC_UNKNOWN, guest_undef_handler);
-
-	test_run_vcpu(vcpu);
-
-	kvm_vm_free(vm);
-}
-
-int main(int argc, char *argv[])
-{
-	struct kvm_vcpu *vcpu;
-	struct kvm_vm *vm;
-	uint64_t pfr0;
-
-	test_disable_default_vgic();
-
-	vm = vm_create_with_one_vcpu(&vcpu, NULL);
-	pfr0 = vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(SYS_ID_AA64PFR0_EL1));
-	__TEST_REQUIRE(FIELD_GET(ID_AA64PFR0_EL1_GIC, pfr0),
-		       "GICv3 not supported.");
-	kvm_vm_free(vm);
-
-	test_guest_no_gicv3();
-
-	return 0;
-}
diff --git a/tools/testing/selftests/kvm/arm64/no-vgic.c b/tools/testing/selftests/kvm/arm64/no-vgic.c
new file mode 100644
index 0000000000000..b14686ef17d12
--- /dev/null
+++ b/tools/testing/selftests/kvm/arm64/no-vgic.c
@@ -0,0 +1,297 @@
+// SPDX-License-Identifier: GPL-2.0
+
+// Check that, on a GICv3-capable system (GICv3 native, or GICv5 with
+// FEAT_GCIE_LEGACY), not configuring GICv3 correctly results in all
+// of the sysregs generating an UNDEF exception. Do the same for GICv5
+// on a GICv5 host.
+
+#include <test_util.h>
+#include <kvm_util.h>
+#include <processor.h>
+
+#include <arm64/gic_v5.h>
+
+static volatile bool handled;
+
+#define __check_sr_read(r)					\
+	({							\
+		uint64_t val;					\
+								\
+		handled = false;				\
+		dsb(sy);					\
+		val = read_sysreg_s(SYS_ ## r);			\
+		val;						\
+	})
+
+#define __check_sr_write(r)					\
+	do {							\
+		handled = false;				\
+		dsb(sy);					\
+		write_sysreg_s(0, SYS_ ## r);			\
+		isb();						\
+	} while (0)
+
+#define __check_gicv5_gicr_op(r)				\
+	({							\
+		uint64_t val;					\
+								\
+		handled = false;				\
+		dsb(sy);					\
+		val = read_sysreg_s(GICV5_OP_GICR_ ## r);	\
+		val;						\
+	})
+
+#define __check_gicv5_gic_op(r)					\
+	do {							\
+		handled = false;				\
+		dsb(sy);					\
+		write_sysreg_s(0, GICV5_OP_GIC_ ## r);		\
+		isb();						\
+	} while (0)
+
+/* Fatal checks */
+#define check_sr_read(r)					\
+	do {							\
+		__check_sr_read(r);				\
+		__GUEST_ASSERT(handled, #r " no read trap");	\
+	} while (0)
+
+#define check_sr_write(r)					\
+	do {							\
+		__check_sr_write(r);				\
+		__GUEST_ASSERT(handled, #r " no write trap");	\
+	} while (0)
+
+#define check_sr_rw(r)				\
+	do {					\
+		check_sr_read(r);		\
+		check_sr_write(r);		\
+	} while (0)
+
+#define check_gicv5_gicr_op(r)					\
+	do {							\
+		__check_gicv5_gicr_op(r);			\
+		__GUEST_ASSERT(handled, #r " no read trap");	\
+	} while (0)
+
+#define check_gicv5_gic_op(r)					\
+	do {							\
+		__check_gicv5_gic_op(r);			\
+		__GUEST_ASSERT(handled, #r " no write trap");	\
+	} while (0)
+
+static void guest_code_gicv3(void)
+{
+	uint64_t val;
+
+	/*
+	 * Check that we advertise that ID_AA64PFR0_EL1.GIC == 0, having
+	 * hidden the feature at runtime without any other userspace action.
+	 */
+	__GUEST_ASSERT(FIELD_GET(ID_AA64PFR0_EL1_GIC,
+				 read_sysreg(id_aa64pfr0_el1)) == 0,
+		       "GICv3 wrongly advertised");
+
+	/*
+	 * Access all GICv3 registers, and fail if we don't get an UNDEF.
+	 * Note that we happily access all the APxRn registers without
+	 * checking their existence, as all we want to see is a failure.
+	 */
+	check_sr_rw(ICC_PMR_EL1);
+	check_sr_read(ICC_IAR0_EL1);
+	check_sr_write(ICC_EOIR0_EL1);
+	check_sr_rw(ICC_HPPIR0_EL1);
+	check_sr_rw(ICC_BPR0_EL1);
+	check_sr_rw(ICC_AP0R0_EL1);
+	check_sr_rw(ICC_AP0R1_EL1);
+	check_sr_rw(ICC_AP0R2_EL1);
+	check_sr_rw(ICC_AP0R3_EL1);
+	check_sr_rw(ICC_AP1R0_EL1);
+	check_sr_rw(ICC_AP1R1_EL1);
+	check_sr_rw(ICC_AP1R2_EL1);
+	check_sr_rw(ICC_AP1R3_EL1);
+	check_sr_write(ICC_DIR_EL1);
+	check_sr_read(ICC_RPR_EL1);
+	check_sr_write(ICC_SGI1R_EL1);
+	check_sr_write(ICC_ASGI1R_EL1);
+	check_sr_write(ICC_SGI0R_EL1);
+	check_sr_read(ICC_IAR1_EL1);
+	check_sr_write(ICC_EOIR1_EL1);
+	check_sr_rw(ICC_HPPIR1_EL1);
+	check_sr_rw(ICC_BPR1_EL1);
+	check_sr_rw(ICC_CTLR_EL1);
+	check_sr_rw(ICC_IGRPEN0_EL1);
+	check_sr_rw(ICC_IGRPEN1_EL1);
+
+	/*
+	 * ICC_SRE_EL1 may not be trappable, as ICC_SRE_EL2.Enable can
+	 * be RAO/WI. Engage in non-fatal accesses, starting with a
+	 * write of 0 to try and disable SRE, and let's see if it
+	 * sticks.
+	 */
+	__check_sr_write(ICC_SRE_EL1);
+	if (!handled)
+		GUEST_PRINTF("ICC_SRE_EL1 write not trapping (OK)\n");
+
+	val = __check_sr_read(ICC_SRE_EL1);
+	if (!handled) {
+		__GUEST_ASSERT((val & BIT(0)),
+			       "ICC_SRE_EL1 not trapped but ICC_SRE_EL1.SRE not set\n");
+		GUEST_PRINTF("ICC_SRE_EL1 read not trapping (OK)\n");
+	}
+
+	GUEST_DONE();
+}
+
+static void guest_code_gicv5(void)
+{
+	/*
+	 * Check that we advertise that ID_AA64PFR2_EL1.GCIE == 0, having
+	 * hidden the feature at runtime without any other userspace action.
+	 */
+	__GUEST_ASSERT(FIELD_GET(ID_AA64PFR2_EL1_GCIE,
+				 read_sysreg_s(SYS_ID_AA64PFR2_EL1)) == 0,
+		       "GICv5 wrongly advertised");
+
+	/*
+	 * Try all GICv5 instructions, and fail if we don't get an UNDEF.
+	 */
+	check_gicv5_gic_op(CDAFF);
+	check_gicv5_gic_op(CDDI);
+	check_gicv5_gic_op(CDDIS);
+	check_gicv5_gic_op(CDEOI);
+	check_gicv5_gic_op(CDHM);
+	check_gicv5_gic_op(CDPEND);
+	check_gicv5_gic_op(CDPRI);
+	check_gicv5_gic_op(CDRCFG);
+	check_gicv5_gicr_op(CDIA);
+	check_gicv5_gicr_op(CDNMIA);
+
+	/* Check General System Register acccesses */
+	check_sr_rw(ICC_APR_EL1);
+	check_sr_rw(ICC_CR0_EL1);
+	check_sr_read(ICC_HPPIR_EL1);
+	check_sr_read(ICC_IAFFIDR_EL1);
+	check_sr_rw(ICC_ICSR_EL1);
+	check_sr_read(ICC_IDR0_EL1);
+	check_sr_rw(ICC_PCR_EL1);
+
+	/* Check PPI System Register accessess */
+	check_sr_rw(ICC_PPI_CACTIVER0_EL1);
+	check_sr_rw(ICC_PPI_CACTIVER1_EL1);
+	check_sr_rw(ICC_PPI_SACTIVER0_EL1);
+	check_sr_rw(ICC_PPI_SACTIVER1_EL1);
+	check_sr_rw(ICC_PPI_CPENDR0_EL1);
+	check_sr_rw(ICC_PPI_CPENDR1_EL1);
+	check_sr_rw(ICC_PPI_SPENDR0_EL1);
+	check_sr_rw(ICC_PPI_SPENDR1_EL1);
+	check_sr_rw(ICC_PPI_ENABLER0_EL1);
+	check_sr_rw(ICC_PPI_ENABLER1_EL1);
+	check_sr_read(ICC_PPI_HMR0_EL1);
+	check_sr_read(ICC_PPI_HMR1_EL1);
+	check_sr_rw(ICC_PPI_PRIORITYR0_EL1);
+	check_sr_rw(ICC_PPI_PRIORITYR1_EL1);
+	check_sr_rw(ICC_PPI_PRIORITYR2_EL1);
+	check_sr_rw(ICC_PPI_PRIORITYR3_EL1);
+	check_sr_rw(ICC_PPI_PRIORITYR4_EL1);
+	check_sr_rw(ICC_PPI_PRIORITYR5_EL1);
+	check_sr_rw(ICC_PPI_PRIORITYR6_EL1);
+	check_sr_rw(ICC_PPI_PRIORITYR7_EL1);
+	check_sr_rw(ICC_PPI_PRIORITYR8_EL1);
+	check_sr_rw(ICC_PPI_PRIORITYR9_EL1);
+	check_sr_rw(ICC_PPI_PRIORITYR10_EL1);
+	check_sr_rw(ICC_PPI_PRIORITYR11_EL1);
+	check_sr_rw(ICC_PPI_PRIORITYR12_EL1);
+	check_sr_rw(ICC_PPI_PRIORITYR13_EL1);
+	check_sr_rw(ICC_PPI_PRIORITYR14_EL1);
+	check_sr_rw(ICC_PPI_PRIORITYR15_EL1);
+
+	GUEST_DONE();
+}
+
+static void guest_undef_handler(struct ex_regs *regs)
+{
+	/* Success, we've gracefully exploded! */
+	handled = true;
+	regs->pc += 4;
+}
+
+static void test_run_vcpu(struct kvm_vcpu *vcpu)
+{
+	struct ucall uc;
+
+	do {
+		vcpu_run(vcpu);
+
+		switch (get_ucall(vcpu, &uc)) {
+		case UCALL_ABORT:
+			REPORT_GUEST_ASSERT(uc);
+			break;
+		case UCALL_PRINTF:
+			printf("%s", uc.buffer);
+			break;
+		case UCALL_DONE:
+			break;
+		default:
+			TEST_FAIL("Unknown ucall %lu", uc.cmd);
+		}
+	} while (uc.cmd != UCALL_DONE);
+}
+
+static void test_guest_no_vgic(void *guest_code)
+{
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm;
+
+	/* Create a VM without a GIC */
+	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
+
+	vm_init_descriptor_tables(vm);
+	vcpu_init_descriptor_tables(vcpu);
+
+	vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT,
+				ESR_ELx_EC_UNKNOWN, guest_undef_handler);
+
+	test_run_vcpu(vcpu);
+
+	kvm_vm_free(vm);
+}
+
+int main(int argc, char *argv[])
+{
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm;
+	bool has_v3, has_v5;
+	uint64_t pfr;
+
+	test_disable_default_vgic();
+
+	vm = vm_create_with_one_vcpu(&vcpu, NULL);
+
+	pfr = vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(SYS_ID_AA64PFR0_EL1));
+	has_v3 = !!FIELD_GET(ID_AA64PFR0_EL1_GIC, pfr);
+
+	pfr = vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(SYS_ID_AA64PFR2_EL1));
+	has_v5 = !!FIELD_GET(ID_AA64PFR2_EL1_GCIE, pfr);
+
+	kvm_vm_free(vm);
+
+	__TEST_REQUIRE(has_v3 || has_v5,
+		       "Neither GICv3 nor GICv5 supported.");
+
+	if (has_v3) {
+		pr_info("Testing no-vgic-v3\n");
+		test_guest_no_vgic(guest_code_gicv3);
+	} else {
+		pr_info("No GICv3 support: skipping no-vgic-v3 test\n");
+	}
+
+	if (has_v5) {
+		pr_info("Testing no-vgic-v5\n");
+		test_guest_no_vgic(guest_code_gicv5);
+	} else {
+		pr_info("No GICv5 support: skipping no-vgic-v5 test\n");
+	}
+
+	return 0;
+}
-- 
2.34.1