commit 5d81f7dc9bca4f4963092433e27b508cbe524a32 upstream.
Now that all our infrastructure is in place, let's expose the availability of ARCH_WORKAROUND_2 to guests. We take this opportunity to tidy up a couple of SMCCC constants.
Acked-by: Christoffer Dall christoffer.dall@arm.com Reviewed-by: Mark Rutland mark.rutland@arm.com Signed-off-by: Marc Zyngier marc.zyngier@arm.com Signed-off-by: Catalin Marinas catalin.marinas@arm.com Signed-off-by: Marc Zyngier marc.zyngier@arm.com --- arch/arm/include/asm/kvm_host.h | 12 ++++++++++++ arch/arm/kvm/psci.c | 18 ++++++++++++++++-- arch/arm64/include/asm/kvm_host.h | 23 +++++++++++++++++++++++ arch/arm64/kvm/reset.c | 4 ++++ 4 files changed, 55 insertions(+), 2 deletions(-)
diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index f4dab20ac9f3..0833d8a1dbbb 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -327,4 +327,16 @@ static inline bool kvm_arm_harden_branch_predictor(void) return false; }
+#define KVM_SSBD_UNKNOWN -1 +#define KVM_SSBD_FORCE_DISABLE 0 +#define KVM_SSBD_KERNEL 1 +#define KVM_SSBD_FORCE_ENABLE 2 +#define KVM_SSBD_MITIGATED 3 + +static inline int kvm_arm_have_ssbd(void) +{ + /* No way to detect it yet, pretend it is not there. */ + return KVM_SSBD_UNKNOWN; +} + #endif /* __ARM_KVM_HOST_H__ */ diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c index 8a9c654f4f87..83365bec04b6 100644 --- a/arch/arm/kvm/psci.c +++ b/arch/arm/kvm/psci.c @@ -403,7 +403,7 @@ static int kvm_psci_call(struct kvm_vcpu *vcpu) int kvm_hvc_call_handler(struct kvm_vcpu *vcpu) { u32 func_id = smccc_get_function(vcpu); - u32 val = PSCI_RET_NOT_SUPPORTED; + u32 val = SMCCC_RET_NOT_SUPPORTED; u32 feature;
switch (func_id) { @@ -415,7 +415,21 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu) switch(feature) { case ARM_SMCCC_ARCH_WORKAROUND_1: if (kvm_arm_harden_branch_predictor()) - val = 0; + val = SMCCC_RET_SUCCESS; + break; + case ARM_SMCCC_ARCH_WORKAROUND_2: + switch (kvm_arm_have_ssbd()) { + case KVM_SSBD_FORCE_DISABLE: + case KVM_SSBD_UNKNOWN: + break; + case KVM_SSBD_KERNEL: + val = SMCCC_RET_SUCCESS; + break; + case KVM_SSBD_FORCE_ENABLE: + case KVM_SSBD_MITIGATED: + val = SMCCC_RET_NOT_REQUIRED; + break; + } break; } break; diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index beeafda89567..4cdfbd01b2de 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -425,4 +425,27 @@ static inline bool kvm_arm_harden_branch_predictor(void) return cpus_have_const_cap(ARM64_HARDEN_BRANCH_PREDICTOR); }
+#define KVM_SSBD_UNKNOWN -1 +#define KVM_SSBD_FORCE_DISABLE 0 +#define KVM_SSBD_KERNEL 1 +#define KVM_SSBD_FORCE_ENABLE 2 +#define KVM_SSBD_MITIGATED 3 + +static inline int kvm_arm_have_ssbd(void) +{ + switch (arm64_get_ssbd_state()) { + case ARM64_SSBD_FORCE_DISABLE: + return KVM_SSBD_FORCE_DISABLE; + case ARM64_SSBD_KERNEL: + return KVM_SSBD_KERNEL; + case ARM64_SSBD_FORCE_ENABLE: + return KVM_SSBD_FORCE_ENABLE; + case ARM64_SSBD_MITIGATED: + return KVM_SSBD_MITIGATED; + case ARM64_SSBD_UNKNOWN: + default: + return KVM_SSBD_UNKNOWN; + } +} + #endif /* __ARM64_KVM_HOST_H__ */ diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c index 5bc460884639..29a27a09f21f 100644 --- a/arch/arm64/kvm/reset.c +++ b/arch/arm64/kvm/reset.c @@ -135,6 +135,10 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu) /* Reset PMU */ kvm_pmu_vcpu_reset(vcpu);
+ /* Default workaround setup is enabled (if supported) */ + if (kvm_arm_have_ssbd() == KVM_SSBD_KERNEL) + vcpu->arch.workaround_flags |= VCPU_WORKAROUND_2_FLAG; + /* Reset timer */ return kvm_timer_vcpu_reset(vcpu, cpu_vtimer_irq); }