[PATCH v2 12/19] KVM: arm64: Move vcpu WFIT flag to the state flag set

Marc Zyngier
2022-06-10T09:35:38Z

The host kernel uses the WFIT flag to remember that a vcpu has used
this instruction and wake it up as required. Move it to the state
set, as nothing in the hypervisor uses this information.

Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/include/asm/kvm_host.h | 4 ++--
arch/arm64/kvm/arch_timer.c | 2 +-
arch/arm64/kvm/arm.c | 2 +-
arch/arm64/kvm/handle_exit.c | 2 +-
4 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 0c22514cb7c7..0fb1a5b86f16 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -521,6 +521,8 @@ struct kvm_vcpu_arch {
#define HOST_SME_ENABLED __vcpu_single_flag(sflags, BIT(1))
/* Physical CPU not in supported_cpus */
#define ON_UNSUPPORTED_CPU __vcpu_single_flag(sflags, BIT(2))
+/* WFIT instruction trapped */
+#define IN_WFIT __vcpu_single_flag(sflags, BIT(3))

/* Pointer to the vcpu's SVE FFR for sve_{save,load}_state() */
#define vcpu_sve_pffr(vcpu) (kern_hyp_va((vcpu)->arch.sve_state) + \
@@ -542,8 +544,6 @@ struct kvm_vcpu_arch {
__size_ret; \
})

-/* vcpu_arch flags field values: */
-#define KVM_ARM64_WFIT (1 << 17) /* WFIT instruction trapped */
#define KVM_GUESTDBG_VALID_MASK (KVM_GUESTDBG_ENABLE | \
KVM_GUESTDBG_USE_SW_BP | \
KVM_GUESTDBG_USE_HW | \
diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c
index 4e39ace073af..5290ca5db663 100644
--- a/arch/arm64/kvm/arch_timer.c
+++ b/arch/arm64/kvm/arch_timer.c
@@ -242,7 +242,7 @@ static bool kvm_timer_irq_can_fire(struct arch_timer_context *timer_ctx)
static bool vcpu_has_wfit_active(struct kvm_vcpu *vcpu)
{
return (cpus_have_final_cap(ARM64_HAS_WFXT) &&
- (vcpu->arch.flags & KVM_ARM64_WFIT));
+ vcpu_get_flag(vcpu, IN_WFIT));
}

static u64 wfit_delay_ns(struct kvm_vcpu *vcpu)
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 5beabbe69585..8b9da9d30485 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -657,7 +657,7 @@ void kvm_vcpu_wfi(struct kvm_vcpu *vcpu)
preempt_enable();

kvm_vcpu_halt(vcpu);
- vcpu->arch.flags &= ~KVM_ARM64_WFIT;
+ vcpu_clear_flag(vcpu, IN_WFIT);
kvm_clear_request(KVM_REQ_UNHALT, vcpu);

preempt_disable();
diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c
index f66c0142b335..d045f5b973b9 100644
--- a/arch/arm64/kvm/handle_exit.c
+++ b/arch/arm64/kvm/handle_exit.c
@@ -120,7 +120,7 @@ static int kvm_handle_wfx(struct kvm_vcpu *vcpu)
kvm_vcpu_on_spin(vcpu, vcpu_mode_priv(vcpu));
} else {
if (esr & ESR_ELx_WFx_ISS_WFxT)
- vcpu->arch.flags |= KVM_ARM64_WFIT;
+ vcpu_set_flag(vcpu, IN_WFIT);

kvm_vcpu_wfi(vcpu);
}
--
2.34.1