On Tue, May 22, 2018 at 04:06:48PM +0100, Marc Zyngier wrote: > 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 <[email protected]> > Signed-off-by: Marc Zyngier <[email protected]>
Reviewed-by: Mark Rutland <[email protected]> Mark. > --- > arch/arm/include/asm/kvm_host.h | 12 ++++++++++++ > arch/arm64/include/asm/kvm_host.h | 23 +++++++++++++++++++++++ > arch/arm64/kvm/reset.c | 4 ++++ > virt/kvm/arm/psci.c | 18 ++++++++++++++++-- > 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 c7c28c885a19..d478766b56c1 100644 > --- a/arch/arm/include/asm/kvm_host.h > +++ b/arch/arm/include/asm/kvm_host.h > @@ -315,6 +315,18 @@ 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_EL1_ENTRY 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; > +} > + > static inline void kvm_vcpu_load_sysregs(struct kvm_vcpu *vcpu) {} > static inline void kvm_vcpu_put_sysregs(struct kvm_vcpu *vcpu) {} > > diff --git a/arch/arm64/include/asm/kvm_host.h > b/arch/arm64/include/asm/kvm_host.h > index 9bef3f69bdcd..082b0dbb85c6 100644 > --- a/arch/arm64/include/asm/kvm_host.h > +++ b/arch/arm64/include/asm/kvm_host.h > @@ -455,6 +455,29 @@ 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_EL1_ENTRY 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_EL1_ENTRY: > + return KVM_SSBD_EL1_ENTRY; > + 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; > + } > +} > + > void kvm_vcpu_load_sysregs(struct kvm_vcpu *vcpu); > void kvm_vcpu_put_sysregs(struct kvm_vcpu *vcpu); > > diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c > index 3256b9228e75..20a7dfee8494 100644 > --- a/arch/arm64/kvm/reset.c > +++ b/arch/arm64/kvm/reset.c > @@ -122,6 +122,10 @@ 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_EL1_ENTRY) > + vcpu->arch.workaround_flags |= VCPU_WORKAROUND_2_FLAG; > + > /* Reset timer */ > return kvm_timer_vcpu_reset(vcpu); > } > diff --git a/virt/kvm/arm/psci.c b/virt/kvm/arm/psci.c > index c4762bef13c6..4843bfa1f986 100644 > --- a/virt/kvm/arm/psci.c > +++ b/virt/kvm/arm/psci.c > @@ -405,7 +405,7 @@ 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) { > @@ -417,7 +417,21 @@ 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_EL1_ENTRY: > + val = SMCCC_RET_SUCCESS; > + break; > + case KVM_SSBD_FORCE_ENABLE: > + case KVM_SSBD_MITIGATED: > + val = SMCCC_RET_NOT_REQUIRED; > + break; > + } > break; > } > break; > -- > 2.14.2 >
