From: Fuad Tabba <tabba@google.com>
To: Marc Zyngier <maz@kernel.org>, Oliver Upton <oupton@kernel.org>,
kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Cc: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>, Joey Gouly <joey.gouly@arm.com>,
Steffen Eiden <seiden@linux.ibm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Zenghui Yu <yuzenghui@huawei.com>,
Vincent Donnefort <vdonnefort@google.com>,
Quentin Perret <qperret@google.com>,
Sebastian Ene <sebastianene@google.com>,
Hyunwoo Kim <imv4bel@gmail.com>, Fuad Tabba <tabba@google.com>
Subject: [PATCH v2 2/8] KVM: arm64: Make vcpu_{read,write}_sys_reg available to HYP code
Date: Fri, 19 Jun 2026 08:07:13 +0100 [thread overview]
Message-ID: <20260619070719.812227-3-tabba@google.com> (raw)
In-Reply-To: <20260619070719.812227-1-tabba@google.com>
The vcpu_{read,write}_sys_reg() accessors are host-only, so helpers
built on them such as kvm_vcpu_set_be()/kvm_vcpu_is_be() cannot be
shared with hyp code. exception.c already wraps them in
__vcpu_{read,write}_sys_reg(), which pick the host- or hyp-side accessor
via has_vhe() and so are valid in any context.
Move those wrappers to kvm_emulate.h as kvm_vcpu_{read,write}_sys_reg()
and switch the callers over, so a follow-up series can share that
emulation code at EL2.
No functional change intended.
Signed-off-by: Fuad Tabba <tabba@google.com>
---
arch/arm64/include/asm/kvm_emulate.h | 22 +++++++++++++++---
arch/arm64/kvm/hyp/exception.c | 34 ++++++++--------------------
2 files changed, 28 insertions(+), 28 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index 5bf3d7e1d92c..80b30fead3d1 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -506,6 +506,22 @@ static inline unsigned long kvm_vcpu_get_mpidr_aff(struct kvm_vcpu *vcpu)
return __vcpu_sys_reg(vcpu, MPIDR_EL1) & MPIDR_HWID_BITMASK;
}
+static inline u64 kvm_vcpu_read_sys_reg(const struct kvm_vcpu *vcpu, int reg)
+{
+ if (has_vhe())
+ return vcpu_read_sys_reg(vcpu, reg);
+
+ return __vcpu_sys_reg(vcpu, reg);
+}
+
+static inline void kvm_vcpu_write_sys_reg(struct kvm_vcpu *vcpu, u64 val, int reg)
+{
+ if (has_vhe())
+ vcpu_write_sys_reg(vcpu, val, reg);
+ else
+ __vcpu_assign_sys_reg(vcpu, reg, val);
+}
+
static inline void kvm_vcpu_set_be(struct kvm_vcpu *vcpu)
{
if (vcpu_mode_is_32bit(vcpu)) {
@@ -516,9 +532,9 @@ static inline void kvm_vcpu_set_be(struct kvm_vcpu *vcpu)
r = vcpu_has_nv(vcpu) ? SCTLR_EL2 : SCTLR_EL1;
- sctlr = vcpu_read_sys_reg(vcpu, r);
+ sctlr = kvm_vcpu_read_sys_reg(vcpu, r);
sctlr |= SCTLR_ELx_EE;
- vcpu_write_sys_reg(vcpu, sctlr, r);
+ kvm_vcpu_write_sys_reg(vcpu, sctlr, r);
}
}
@@ -533,7 +549,7 @@ static inline bool kvm_vcpu_is_be(struct kvm_vcpu *vcpu)
r = is_hyp_ctxt(vcpu) ? SCTLR_EL2 : SCTLR_EL1;
bit = vcpu_mode_priv(vcpu) ? SCTLR_ELx_EE : SCTLR_EL1_E0E;
- return vcpu_read_sys_reg(vcpu, r) & bit;
+ return kvm_vcpu_read_sys_reg(vcpu, r) & bit;
}
static inline unsigned long vcpu_data_guest_to_host(struct kvm_vcpu *vcpu,
diff --git a/arch/arm64/kvm/hyp/exception.c b/arch/arm64/kvm/hyp/exception.c
index bef40ddb16db..2cb68dc7d441 100644
--- a/arch/arm64/kvm/hyp/exception.c
+++ b/arch/arm64/kvm/hyp/exception.c
@@ -20,22 +20,6 @@
#error Hypervisor code only!
#endif
-static inline u64 __vcpu_read_sys_reg(const struct kvm_vcpu *vcpu, int reg)
-{
- if (has_vhe())
- return vcpu_read_sys_reg(vcpu, reg);
-
- return __vcpu_sys_reg(vcpu, reg);
-}
-
-static inline void __vcpu_write_sys_reg(struct kvm_vcpu *vcpu, u64 val, int reg)
-{
- if (has_vhe())
- vcpu_write_sys_reg(vcpu, val, reg);
- else
- __vcpu_assign_sys_reg(vcpu, reg, val);
-}
-
static void __vcpu_write_spsr(struct kvm_vcpu *vcpu, unsigned long target_mode,
u64 val)
{
@@ -101,14 +85,14 @@ static void enter_exception64(struct kvm_vcpu *vcpu, unsigned long target_mode,
switch (target_mode) {
case PSR_MODE_EL1h:
- vbar = __vcpu_read_sys_reg(vcpu, VBAR_EL1);
- sctlr = __vcpu_read_sys_reg(vcpu, SCTLR_EL1);
- __vcpu_write_sys_reg(vcpu, *vcpu_pc(vcpu), ELR_EL1);
+ vbar = kvm_vcpu_read_sys_reg(vcpu, VBAR_EL1);
+ sctlr = kvm_vcpu_read_sys_reg(vcpu, SCTLR_EL1);
+ kvm_vcpu_write_sys_reg(vcpu, *vcpu_pc(vcpu), ELR_EL1);
break;
case PSR_MODE_EL2h:
- vbar = __vcpu_read_sys_reg(vcpu, VBAR_EL2);
- sctlr = __vcpu_read_sys_reg(vcpu, SCTLR_EL2);
- __vcpu_write_sys_reg(vcpu, *vcpu_pc(vcpu), ELR_EL2);
+ vbar = kvm_vcpu_read_sys_reg(vcpu, VBAR_EL2);
+ sctlr = kvm_vcpu_read_sys_reg(vcpu, SCTLR_EL2);
+ kvm_vcpu_write_sys_reg(vcpu, *vcpu_pc(vcpu), ELR_EL2);
break;
default:
/* Don't do that */
@@ -185,7 +169,7 @@ static void enter_exception64(struct kvm_vcpu *vcpu, unsigned long target_mode,
*/
static unsigned long get_except32_cpsr(struct kvm_vcpu *vcpu, u32 mode)
{
- u32 sctlr = __vcpu_read_sys_reg(vcpu, SCTLR_EL1);
+ u32 sctlr = kvm_vcpu_read_sys_reg(vcpu, SCTLR_EL1);
unsigned long old, new;
old = *vcpu_cpsr(vcpu);
@@ -281,7 +265,7 @@ static void enter_exception32(struct kvm_vcpu *vcpu, u32 mode, u32 vect_offset)
{
unsigned long spsr = *vcpu_cpsr(vcpu);
bool is_thumb = (spsr & PSR_AA32_T_BIT);
- u32 sctlr = __vcpu_read_sys_reg(vcpu, SCTLR_EL1);
+ u32 sctlr = kvm_vcpu_read_sys_reg(vcpu, SCTLR_EL1);
u32 return_address;
*vcpu_cpsr(vcpu) = get_except32_cpsr(vcpu, mode);
@@ -305,7 +289,7 @@ static void enter_exception32(struct kvm_vcpu *vcpu, u32 mode, u32 vect_offset)
if (sctlr & (1 << 13))
vect_offset += 0xffff0000;
else /* always have security exceptions */
- vect_offset += __vcpu_read_sys_reg(vcpu, VBAR_EL1);
+ vect_offset += kvm_vcpu_read_sys_reg(vcpu, VBAR_EL1);
*vcpu_pc(vcpu) = vect_offset;
}
--
2.55.0.rc0.738.g0c8ab3ebcc-goog
next prev parent reply other threads:[~2026-06-19 7:07 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-19 7:07 [PATCH v2 0/8] KVM: arm64: Rework pKVM vCPU state synchronisation Fuad Tabba
2026-06-19 7:07 ` [PATCH v2 1/8] KVM: arm64: Extract MPIDR computation into a shared header Fuad Tabba
2026-06-19 13:24 ` Vincent Donnefort
2026-06-19 7:07 ` Fuad Tabba [this message]
2026-06-19 13:26 ` [PATCH v2 2/8] KVM: arm64: Make vcpu_{read,write}_sys_reg available to HYP code Vincent Donnefort
2026-06-19 7:07 ` [PATCH v2 3/8] KVM: arm64: Factor out reusable vCPU reset helpers Fuad Tabba
2026-06-19 13:29 ` Vincent Donnefort
2026-06-19 7:07 ` [PATCH v2 4/8] KVM: arm64: Move PSCI helper functions to a shared header Fuad Tabba
2026-06-19 13:30 ` Vincent Donnefort
2026-06-19 7:07 ` [PATCH v2 5/8] KVM: arm64: Add host and hypervisor vCPU lookup primitives Fuad Tabba
2026-06-19 13:31 ` Vincent Donnefort
2026-06-19 7:07 ` [PATCH v2 6/8] KVM: arm64: Minimise EL2's exposure of host VGIC state during world switch Fuad Tabba
2026-06-19 7:07 ` [PATCH v2 7/8] KVM: arm64: Add primitives to flush/sync the VGIC state at EL2 Fuad Tabba
2026-06-19 7:07 ` [PATCH v2 8/8] KVM: arm64: Implement lazy vCPU state sync for non-protected guests Fuad Tabba
2026-06-19 13:12 ` Vincent Donnefort
2026-06-19 16:41 ` Fuad Tabba
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