diff options
| author | Andre Przywara <andre.przywara@arm.com> | 2019-05-03 15:27:48 +0100 |
|---|---|---|
| committer | Marc Zyngier <marc.zyngier@arm.com> | 2019-07-05 13:56:27 +0100 |
| commit | c118bbb52743df70e6297671606c1c08edc659fe (patch) | |
| tree | 3058edcfc6f08fa7b68f9e5ff037c9dc219255a6 /arch/arm/include | |
| parent | 80f393a23be68e2f8a0f74258d6155438c200bbd (diff) | |
| download | lwn-c118bbb52743df70e6297671606c1c08edc659fe.tar.gz lwn-c118bbb52743df70e6297671606c1c08edc659fe.zip | |
arm64: KVM: Propagate full Spectre v2 workaround state to KVM guests
Recent commits added the explicit notion of "workaround not required" to
the state of the Spectre v2 (aka. BP_HARDENING) workaround, where we
just had "needed" and "unknown" before.
Export this knowledge to the rest of the kernel and enhance the existing
kvm_arm_harden_branch_predictor() to report this new state as well.
Export this new state to guests when they use KVM's firmware interface
emulation.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'arch/arm/include')
| -rw-r--r-- | arch/arm/include/asm/kvm_host.h | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index f80418ddeb60..e74e8f408987 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -362,7 +362,11 @@ static inline void kvm_vcpu_pmu_restore_host(struct kvm_vcpu *vcpu) {} 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) +#define KVM_BP_HARDEN_UNKNOWN -1 +#define KVM_BP_HARDEN_WA_NEEDED 0 +#define KVM_BP_HARDEN_NOT_REQUIRED 1 + +static inline int kvm_arm_harden_branch_predictor(void) { switch(read_cpuid_part()) { #ifdef CONFIG_HARDEN_BRANCH_PREDICTOR @@ -370,10 +374,12 @@ static inline bool kvm_arm_harden_branch_predictor(void) case ARM_CPU_PART_CORTEX_A12: case ARM_CPU_PART_CORTEX_A15: case ARM_CPU_PART_CORTEX_A17: - return true; + return KVM_BP_HARDEN_WA_NEEDED; #endif + case ARM_CPU_PART_CORTEX_A7: + return KVM_BP_HARDEN_NOT_REQUIRED; default: - return false; + return KVM_BP_HARDEN_UNKNOWN; } } |