diff options
| -rw-r--r-- | arch/arm/include/asm/kvm_host.h | 7 | ||||
| -rw-r--r-- | arch/arm64/include/asm/kvm_host.h | 6 | ||||
| -rw-r--r-- | include/linux/arm-smccc.h | 5 | ||||
| -rw-r--r-- | virt/kvm/arm/psci.c | 9 |
4 files changed, 26 insertions, 1 deletions
diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index acbf9ec7b396..ef54013b5b9f 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -306,4 +306,11 @@ static inline void kvm_fpsimd_flush_cpu_state(void) {} static inline void kvm_arm_vhe_guest_enter(void) {} static inline void kvm_arm_vhe_guest_exit(void) {} + +static inline bool kvm_arm_harden_branch_predictor(void) +{ + /* No way to detect it yet, pretend it is not there. */ + return false; +} + #endif /* __ARM_KVM_HOST_H__ */ diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 4485ae8e98de..a73f63aca68e 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -415,4 +415,10 @@ static inline void kvm_arm_vhe_guest_exit(void) { local_daif_restore(DAIF_PROCCTX_NOIRQ); } + +static inline bool kvm_arm_harden_branch_predictor(void) +{ + return cpus_have_const_cap(ARM64_HARDEN_BRANCH_PREDICTOR); +} + #endif /* __ARM64_KVM_HOST_H__ */ diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h index dc68aa5a7261..e1ef944ef1da 100644 --- a/include/linux/arm-smccc.h +++ b/include/linux/arm-smccc.h @@ -73,6 +73,11 @@ ARM_SMCCC_SMC_32, \ 0, 1) +#define ARM_SMCCC_ARCH_WORKAROUND_1 \ + ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \ + ARM_SMCCC_SMC_32, \ + 0, 0x8000) + #ifndef __ASSEMBLY__ #include <linux/linkage.h> diff --git a/virt/kvm/arm/psci.c b/virt/kvm/arm/psci.c index e105c1153794..6919352cbf15 100644 --- a/virt/kvm/arm/psci.c +++ b/virt/kvm/arm/psci.c @@ -405,13 +405,20 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu) { u32 func_id = smccc_get_function(vcpu); u32 val = PSCI_RET_NOT_SUPPORTED; + u32 feature; switch (func_id) { case ARM_SMCCC_VERSION_FUNC_ID: val = ARM_SMCCC_VERSION_1_1; break; case ARM_SMCCC_ARCH_FEATURES_FUNC_ID: - /* Nothing supported yet */ + feature = smccc_get_arg1(vcpu); + switch(feature) { + case ARM_SMCCC_ARCH_WORKAROUND_1: + if (kvm_arm_harden_branch_predictor()) + val = 0; + break; + } break; default: return kvm_psci_call(vcpu); |