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/arm64/include | |
| parent | 80f393a23be68e2f8a0f74258d6155438c200bbd (diff) | |
| download | linux-stable-c118bbb52743df70e6297671606c1c08edc659fe.tar.gz linux-stable-c118bbb52743df70e6297671606c1c08edc659fe.tar.bz2 linux-stable-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/arm64/include')
| -rw-r--r-- | arch/arm64/include/asm/cpufeature.h | 6 | ||||
| -rw-r--r-- | arch/arm64/include/asm/kvm_host.h | 16 |
2 files changed, 20 insertions, 2 deletions
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index 373799b7982f..948427f6b3d9 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -614,6 +614,12 @@ static inline bool system_uses_irq_prio_masking(void) cpus_have_const_cap(ARM64_HAS_IRQ_PRIO_MASKING); } +#define ARM64_BP_HARDEN_UNKNOWN -1 +#define ARM64_BP_HARDEN_WA_NEEDED 0 +#define ARM64_BP_HARDEN_NOT_REQUIRED 1 + +int get_spectre_v2_workaround_state(void); + #define ARM64_SSBD_UNKNOWN -1 #define ARM64_SSBD_FORCE_DISABLE 0 #define ARM64_SSBD_KERNEL 1 diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index c328191aa202..d9770daf3d7d 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -620,9 +620,21 @@ static inline void kvm_arm_vhe_guest_exit(void) isb(); } -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) { - return cpus_have_const_cap(ARM64_HARDEN_BRANCH_PREDICTOR); + switch (get_spectre_v2_workaround_state()) { + case ARM64_BP_HARDEN_WA_NEEDED: + return KVM_BP_HARDEN_WA_NEEDED; + case ARM64_BP_HARDEN_NOT_REQUIRED: + return KVM_BP_HARDEN_NOT_REQUIRED; + case ARM64_BP_HARDEN_UNKNOWN: + default: + return KVM_BP_HARDEN_UNKNOWN; + } } #define KVM_SSBD_UNKNOWN -1 |