* [PATCH 1/6] KVM: arm64: Return error from kvm_arch_init_vm() on allocation failure
2022-06-09 12:12 [PATCH 0/6] KVM/arm64: Minor/trivial fixes from pKVM mega-patch Will Deacon
@ 2022-06-09 12:12 ` Will Deacon
2022-06-09 12:12 ` [PATCH 2/6] KVM: arm64: Handle all ID registers trapped for a protected VM Will Deacon
` (6 subsequent siblings)
7 siblings, 0 replies; 10+ messages in thread
From: Will Deacon @ 2022-06-09 12:12 UTC (permalink / raw)
To: kvmarm
Cc: Will Deacon, Marc Zyngier, Alexandru Elisei, kernel-team,
linux-arm-kernel
If we fail to allocate the 'supported_cpus' cpumask in kvm_arch_init_vm()
then be sure to return -ENOMEM instead of success (0) on the failure
path.
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
---
arch/arm64/kvm/arm.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 400bb0fe2745..0da0f06037db 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -150,8 +150,10 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
if (ret)
goto out_free_stage2_pgd;
- if (!zalloc_cpumask_var(&kvm->arch.supported_cpus, GFP_KERNEL))
+ if (!zalloc_cpumask_var(&kvm->arch.supported_cpus, GFP_KERNEL)) {
+ ret = -ENOMEM;
goto out_free_stage2_pgd;
+ }
cpumask_copy(kvm->arch.supported_cpus, cpu_possible_mask);
kvm_vgic_early_init(kvm);
--
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^ permalink raw reply related [flat|nested] 10+ messages in thread* [PATCH 2/6] KVM: arm64: Handle all ID registers trapped for a protected VM
2022-06-09 12:12 [PATCH 0/6] KVM/arm64: Minor/trivial fixes from pKVM mega-patch Will Deacon
2022-06-09 12:12 ` [PATCH 1/6] KVM: arm64: Return error from kvm_arch_init_vm() on allocation failure Will Deacon
@ 2022-06-09 12:12 ` Will Deacon
2022-06-14 5:57 ` Reiji Watanabe
2022-06-09 12:12 ` [PATCH 3/6] KVM: arm64: Ignore 'kvm-arm.mode=protected' when using VHE Will Deacon
` (5 subsequent siblings)
7 siblings, 1 reply; 10+ messages in thread
From: Will Deacon @ 2022-06-09 12:12 UTC (permalink / raw)
To: kvmarm
Cc: Will Deacon, Marc Zyngier, Alexandru Elisei, kernel-team,
linux-arm-kernel
From: Marc Zyngier <maz@kernel.org>
A protected VM accessing ID_AA64ISAR2_EL1 gets punished with an UNDEF,
while it really should only get a zero back if the register is not
handled by the hypervisor emulation (as mandated by the architecture).
Introduce all the missing ID registers (including the unallocated ones),
and have them to return 0.
Reported-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/kvm/hyp/nvhe/sys_regs.c | 42 ++++++++++++++++++++++++------
1 file changed, 34 insertions(+), 8 deletions(-)
diff --git a/arch/arm64/kvm/hyp/nvhe/sys_regs.c b/arch/arm64/kvm/hyp/nvhe/sys_regs.c
index b6d86e423319..35a4331ba5f3 100644
--- a/arch/arm64/kvm/hyp/nvhe/sys_regs.c
+++ b/arch/arm64/kvm/hyp/nvhe/sys_regs.c
@@ -243,15 +243,9 @@ u64 pvm_read_id_reg(const struct kvm_vcpu *vcpu, u32 id)
case SYS_ID_AA64MMFR2_EL1:
return get_pvm_id_aa64mmfr2(vcpu);
default:
- /*
- * Should never happen because all cases are covered in
- * pvm_sys_reg_descs[].
- */
- WARN_ON(1);
- break;
+ /* Unhandled ID register, RAZ */
+ return 0;
}
-
- return 0;
}
static u64 read_id_reg(const struct kvm_vcpu *vcpu,
@@ -332,6 +326,16 @@ static bool pvm_gic_read_sre(struct kvm_vcpu *vcpu,
/* Mark the specified system register as an AArch64 feature id register. */
#define AARCH64(REG) { SYS_DESC(REG), .access = pvm_access_id_aarch64 }
+/*
+ * sys_reg_desc initialiser for architecturally unallocated cpufeature ID
+ * register with encoding Op0=3, Op1=0, CRn=0, CRm=crm, Op2=op2
+ * (1 <= crm < 8, 0 <= Op2 < 8).
+ */
+#define ID_UNALLOCATED(crm, op2) { \
+ Op0(3), Op1(0), CRn(0), CRm(crm), Op2(op2), \
+ .access = pvm_access_id_aarch64, \
+}
+
/* Mark the specified system register as Read-As-Zero/Write-Ignored */
#define RAZ_WI(REG) { SYS_DESC(REG), .access = pvm_access_raz_wi }
@@ -375,24 +379,46 @@ static const struct sys_reg_desc pvm_sys_reg_descs[] = {
AARCH32(SYS_MVFR0_EL1),
AARCH32(SYS_MVFR1_EL1),
AARCH32(SYS_MVFR2_EL1),
+ ID_UNALLOCATED(3,3),
AARCH32(SYS_ID_PFR2_EL1),
AARCH32(SYS_ID_DFR1_EL1),
AARCH32(SYS_ID_MMFR5_EL1),
+ ID_UNALLOCATED(3,7),
/* AArch64 ID registers */
/* CRm=4 */
AARCH64(SYS_ID_AA64PFR0_EL1),
AARCH64(SYS_ID_AA64PFR1_EL1),
+ ID_UNALLOCATED(4,2),
+ ID_UNALLOCATED(4,3),
AARCH64(SYS_ID_AA64ZFR0_EL1),
+ ID_UNALLOCATED(4,5),
+ ID_UNALLOCATED(4,6),
+ ID_UNALLOCATED(4,7),
AARCH64(SYS_ID_AA64DFR0_EL1),
AARCH64(SYS_ID_AA64DFR1_EL1),
+ ID_UNALLOCATED(5,2),
+ ID_UNALLOCATED(5,3),
AARCH64(SYS_ID_AA64AFR0_EL1),
AARCH64(SYS_ID_AA64AFR1_EL1),
+ ID_UNALLOCATED(5,6),
+ ID_UNALLOCATED(5,7),
AARCH64(SYS_ID_AA64ISAR0_EL1),
AARCH64(SYS_ID_AA64ISAR1_EL1),
+ AARCH64(SYS_ID_AA64ISAR2_EL1),
+ ID_UNALLOCATED(6,3),
+ ID_UNALLOCATED(6,4),
+ ID_UNALLOCATED(6,5),
+ ID_UNALLOCATED(6,6),
+ ID_UNALLOCATED(6,7),
AARCH64(SYS_ID_AA64MMFR0_EL1),
AARCH64(SYS_ID_AA64MMFR1_EL1),
AARCH64(SYS_ID_AA64MMFR2_EL1),
+ ID_UNALLOCATED(7,3),
+ ID_UNALLOCATED(7,4),
+ ID_UNALLOCATED(7,5),
+ ID_UNALLOCATED(7,6),
+ ID_UNALLOCATED(7,7),
/* Scalable Vector Registers are restricted. */
--
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^ permalink raw reply related [flat|nested] 10+ messages in thread* [PATCH 3/6] KVM: arm64: Ignore 'kvm-arm.mode=protected' when using VHE
2022-06-09 12:12 [PATCH 0/6] KVM/arm64: Minor/trivial fixes from pKVM mega-patch Will Deacon
2022-06-09 12:12 ` [PATCH 1/6] KVM: arm64: Return error from kvm_arch_init_vm() on allocation failure Will Deacon
2022-06-09 12:12 ` [PATCH 2/6] KVM: arm64: Handle all ID registers trapped for a protected VM Will Deacon
@ 2022-06-09 12:12 ` Will Deacon
2022-06-09 12:12 ` [PATCH 4/6] KVM: arm64: Extend comment in has_vhe() Will Deacon
` (4 subsequent siblings)
7 siblings, 0 replies; 10+ messages in thread
From: Will Deacon @ 2022-06-09 12:12 UTC (permalink / raw)
To: kvmarm
Cc: Will Deacon, Marc Zyngier, Alexandru Elisei, kernel-team,
linux-arm-kernel, David Brazdil, Mark Rutland
Ignore 'kvm-arm.mode=protected' when using VHE so that kvm_get_mode()
only returns KVM_MODE_PROTECTED on systems where the feature is available.
Cc: David Brazdil <dbrazdil@google.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
---
Documentation/admin-guide/kernel-parameters.txt | 1 -
arch/arm64/kernel/cpufeature.c | 10 +---------
arch/arm64/kvm/arm.c | 6 +++++-
3 files changed, 6 insertions(+), 11 deletions(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 8090130b544b..97c16aa2f53f 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2469,7 +2469,6 @@
protected: nVHE-based mode with support for guests whose
state is kept private from the host.
- Not valid if the kernel is running in EL2.
Defaults to VHE/nVHE based on hardware support. Setting
mode to "protected" will disable kexec and hibernation
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 42ea2bd856c6..79fac13ab2ef 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -1974,15 +1974,7 @@ static void cpu_enable_mte(struct arm64_cpu_capabilities const *cap)
#ifdef CONFIG_KVM
static bool is_kvm_protected_mode(const struct arm64_cpu_capabilities *entry, int __unused)
{
- if (kvm_get_mode() != KVM_MODE_PROTECTED)
- return false;
-
- if (is_kernel_in_hyp_mode()) {
- pr_warn("Protected KVM not available with VHE\n");
- return false;
- }
-
- return true;
+ return kvm_get_mode() == KVM_MODE_PROTECTED;
}
#endif /* CONFIG_KVM */
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 0da0f06037db..a0188144a122 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -2273,7 +2273,11 @@ static int __init early_kvm_mode_cfg(char *arg)
return -EINVAL;
if (strcmp(arg, "protected") == 0) {
- kvm_mode = KVM_MODE_PROTECTED;
+ if (!is_kernel_in_hyp_mode())
+ kvm_mode = KVM_MODE_PROTECTED;
+ else
+ pr_warn_once("Protected KVM not available with VHE\n");
+
return 0;
}
--
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^ permalink raw reply related [flat|nested] 10+ messages in thread* [PATCH 4/6] KVM: arm64: Extend comment in has_vhe()
2022-06-09 12:12 [PATCH 0/6] KVM/arm64: Minor/trivial fixes from pKVM mega-patch Will Deacon
` (2 preceding siblings ...)
2022-06-09 12:12 ` [PATCH 3/6] KVM: arm64: Ignore 'kvm-arm.mode=protected' when using VHE Will Deacon
@ 2022-06-09 12:12 ` Will Deacon
2022-06-09 12:12 ` [PATCH 5/6] KVM: arm64: Remove redundant hyp_assert_lock_held() assertions Will Deacon
` (3 subsequent siblings)
7 siblings, 0 replies; 10+ messages in thread
From: Will Deacon @ 2022-06-09 12:12 UTC (permalink / raw)
To: kvmarm
Cc: Will Deacon, Marc Zyngier, Alexandru Elisei, kernel-team,
linux-arm-kernel, David Brazdil, Mark Rutland
has_vhe() expands to a compile-time constant when evaluated from the VHE
or nVHE code, alternatively checking a static key when called from
elsewhere in the kernel. On face value, this looks like a case of
premature optimization, but in fact this allows symbol references on
VHE-specific code paths to be dropped from the nVHE object.
Expand the comment in has_vhe() to make this clearer, hopefully
discouraging anybody from simplifying the code.
Cc: David Brazdil <dbrazdil@google.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
---
arch/arm64/include/asm/virt.h | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h
index 3c8af033a997..0e80db4327b6 100644
--- a/arch/arm64/include/asm/virt.h
+++ b/arch/arm64/include/asm/virt.h
@@ -113,6 +113,9 @@ static __always_inline bool has_vhe(void)
/*
* Code only run in VHE/NVHE hyp context can assume VHE is present or
* absent. Otherwise fall back to caps.
+ * This allows the compiler to discard VHE-specific code from the
+ * nVHE object, reducing the number of external symbol references
+ * needed to link.
*/
if (is_vhe_hyp_code())
return true;
--
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^ permalink raw reply related [flat|nested] 10+ messages in thread* [PATCH 5/6] KVM: arm64: Remove redundant hyp_assert_lock_held() assertions
2022-06-09 12:12 [PATCH 0/6] KVM/arm64: Minor/trivial fixes from pKVM mega-patch Will Deacon
` (3 preceding siblings ...)
2022-06-09 12:12 ` [PATCH 4/6] KVM: arm64: Extend comment in has_vhe() Will Deacon
@ 2022-06-09 12:12 ` Will Deacon
2022-06-09 12:12 ` [PATCH 6/6] KVM: arm64: Drop stale comment Will Deacon
` (2 subsequent siblings)
7 siblings, 0 replies; 10+ messages in thread
From: Will Deacon @ 2022-06-09 12:12 UTC (permalink / raw)
To: kvmarm
Cc: Will Deacon, Marc Zyngier, Alexandru Elisei, kernel-team,
linux-arm-kernel
host_stage2_try() asserts that the KVM host lock is held, so there's no
need to duplicate the assertion in its wrappers.
Signed-off-by: Will Deacon <will@kernel.org>
---
arch/arm64/kvm/hyp/nvhe/mem_protect.c | 4 ----
1 file changed, 4 deletions(-)
diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
index 78edf077fa3b..1e78acf9662e 100644
--- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
+++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
@@ -314,15 +314,11 @@ static int host_stage2_adjust_range(u64 addr, struct kvm_mem_range *range)
int host_stage2_idmap_locked(phys_addr_t addr, u64 size,
enum kvm_pgtable_prot prot)
{
- hyp_assert_lock_held(&host_kvm.lock);
-
return host_stage2_try(__host_stage2_idmap, addr, addr + size, prot);
}
int host_stage2_set_owner_locked(phys_addr_t addr, u64 size, u8 owner_id)
{
- hyp_assert_lock_held(&host_kvm.lock);
-
return host_stage2_try(kvm_pgtable_stage2_set_owner, &host_kvm.pgt,
addr, size, &host_s2_pool, owner_id);
}
--
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^ permalink raw reply related [flat|nested] 10+ messages in thread* [PATCH 6/6] KVM: arm64: Drop stale comment
2022-06-09 12:12 [PATCH 0/6] KVM/arm64: Minor/trivial fixes from pKVM mega-patch Will Deacon
` (4 preceding siblings ...)
2022-06-09 12:12 ` [PATCH 5/6] KVM: arm64: Remove redundant hyp_assert_lock_held() assertions Will Deacon
@ 2022-06-09 12:12 ` Will Deacon
2022-06-09 12:19 ` [PATCH 0/6] KVM/arm64: Minor/trivial fixes from pKVM mega-patch Marc Zyngier
2022-06-09 12:26 ` Marc Zyngier
7 siblings, 0 replies; 10+ messages in thread
From: Will Deacon @ 2022-06-09 12:12 UTC (permalink / raw)
To: kvmarm
Cc: Will Deacon, Marc Zyngier, Alexandru Elisei, kernel-team,
linux-arm-kernel
From: Marc Zyngier <maz@kernel.org>
The layout of 'struct kvm_vcpu_arch' has evolved significantly since
the initial port of KVM/arm64, so remove the stale comment suggesting
that a prefix of the structure is used exclusively from assembly code.
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/include/asm/kvm_host.h | 5 -----
1 file changed, 5 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 47a1e25e25bb..de32152cea04 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -362,11 +362,6 @@ struct kvm_vcpu_arch {
struct arch_timer_cpu timer_cpu;
struct kvm_pmu pmu;
- /*
- * Anything that is not used directly from assembly code goes
- * here.
- */
-
/*
* Guest registers we preserve during guest debugging.
*
--
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^ permalink raw reply related [flat|nested] 10+ messages in thread* Re: [PATCH 0/6] KVM/arm64: Minor/trivial fixes from pKVM mega-patch
2022-06-09 12:12 [PATCH 0/6] KVM/arm64: Minor/trivial fixes from pKVM mega-patch Will Deacon
` (5 preceding siblings ...)
2022-06-09 12:12 ` [PATCH 6/6] KVM: arm64: Drop stale comment Will Deacon
@ 2022-06-09 12:19 ` Marc Zyngier
2022-06-09 12:26 ` Marc Zyngier
7 siblings, 0 replies; 10+ messages in thread
From: Marc Zyngier @ 2022-06-09 12:19 UTC (permalink / raw)
To: Will Deacon; +Cc: kvmarm, Alexandru Elisei, kernel-team, linux-arm-kernel
On Thu, 09 Jun 2022 13:12:17 +0100,
Will Deacon <will@kernel.org> wrote:
>
> Hi folks,
>
> These six KVM/arm64 patches are very minor fixes (including "fixes" to
> comments) which were previously posted as part of the pKVM mega-patch
> but which can be merged independently of the rest of that. Marc -- I'm
> not sure whether it's even worth taking these for 5.19, but here they
> are so you can have a look and decide yourself.
They are all tragically simple, and patch 2 actually qualifies as a
fix (a legitimate guest would fail to run correctly).
Also, the pKVM series could do with a bit of diet, so I'm inclined to
take these in right now.
M.
--
Without deviation from the norm, progress is not possible.
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^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [PATCH 0/6] KVM/arm64: Minor/trivial fixes from pKVM mega-patch
2022-06-09 12:12 [PATCH 0/6] KVM/arm64: Minor/trivial fixes from pKVM mega-patch Will Deacon
` (6 preceding siblings ...)
2022-06-09 12:19 ` [PATCH 0/6] KVM/arm64: Minor/trivial fixes from pKVM mega-patch Marc Zyngier
@ 2022-06-09 12:26 ` Marc Zyngier
7 siblings, 0 replies; 10+ messages in thread
From: Marc Zyngier @ 2022-06-09 12:26 UTC (permalink / raw)
To: kvmarm, Will Deacon; +Cc: linux-arm-kernel, kernel-team
On Thu, 9 Jun 2022 13:12:17 +0100, Will Deacon wrote:
> These six KVM/arm64 patches are very minor fixes (including "fixes" to
> comments) which were previously posted as part of the pKVM mega-patch
> but which can be merged independently of the rest of that. Marc -- I'm
> not sure whether it's even worth taking these for 5.19, but here they
> are so you can have a look and decide yourself.
>
> Series based on 5.19-rc1.
>
> [...]
Applied to fixes, thanks!
[1/6] KVM: arm64: Return error from kvm_arch_init_vm() on allocation failure
commit: ae187fec75aa670a551d9662f83e3947d3f02a69
[2/6] KVM: arm64: Handle all ID registers trapped for a protected VM
commit: fa7a17214488ef7df347dcd1a5594f69ea17f4dc
[3/6] KVM: arm64: Ignore 'kvm-arm.mode=protected' when using VHE
commit: cde5042adf11b0a30a6ce0ec3d071afcf8d2efaf
[4/6] KVM: arm64: Extend comment in has_vhe()
commit: 112f3bab41113dc53b4f35e9034b2208245bc002
[5/6] KVM: arm64: Remove redundant hyp_assert_lock_held() assertions
commit: 5879c97f37022ff22a3f13174c24fcf2807fdbc0
[6/6] KVM: arm64: Drop stale comment
commit: bcbfb588cf323929ac46767dd14e392016bbce04
Cheers,
M.
--
Marc Zyngier <maz@kernel.org>
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^ permalink raw reply [flat|nested] 10+ messages in thread