diff options
| author | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2018-04-25 22:04:25 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-12-17 21:55:14 +0100 |
| commit | 0109a1b0a5cababd514671b517722585302c0d4f (patch) | |
| tree | 11a38c2b543da04ab2e01033c6d3b5ae6160cfab /arch | |
| parent | 2658e4d66deca4c1fc6eb59514bded62dd0a7812 (diff) | |
x86/KVM/VMX: Expose SPEC_CTRL Bit(2) to the guest
commit da39556f66f5cfe8f9c989206974f1cb16ca5d7c upstream.
Expose the CPUID.7.EDX[31] bit to the guest, and also guard against various
combinations of SPEC_CTRL MSR values.
The handling of the MSR (to take into account the host value of SPEC_CTRL
Bit(2)) is taken care of in patch:
KVM/SVM/VMX/x86/spectre_v2: Support the combination of guest and host IBRS
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
[dwmw2: Handle 4.9 guest CPUID differences, rename
guest_cpu_has_ibrs() → guest_cpu_has_spec_ctrl()]
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 4.4: Update feature bit name]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kvm/cpuid.c | 2 | ||||
| -rw-r--r-- | arch/x86/kvm/cpuid.h | 4 | ||||
| -rw-r--r-- | arch/x86/kvm/svm.c | 4 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx.c | 6 |
4 files changed, 8 insertions, 8 deletions
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 0ab72a8387d4..6b20e0a823da 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -364,7 +364,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, /* cpuid 7.0.edx*/ const u32 kvm_cpuid_7_0_edx_x86_features = - F(SPEC_CTRL) | F(ARCH_CAPABILITIES); + F(SPEC_CTRL) | F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES); /* all calls to cpuid_count() should be made on the same cpu */ get_cpu(); diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h index 7f74d7e18a01..31ff5d2d0536 100644 --- a/arch/x86/kvm/cpuid.h +++ b/arch/x86/kvm/cpuid.h @@ -170,7 +170,7 @@ static inline bool guest_cpuid_has_ibpb(struct kvm_vcpu *vcpu) return best && (best->edx & bit(X86_FEATURE_SPEC_CTRL)); } -static inline bool guest_cpuid_has_ibrs(struct kvm_vcpu *vcpu) +static inline bool guest_cpuid_has_spec_ctrl(struct kvm_vcpu *vcpu) { struct kvm_cpuid_entry2 *best; @@ -178,7 +178,7 @@ static inline bool guest_cpuid_has_ibrs(struct kvm_vcpu *vcpu) if (best && (best->ebx & bit(X86_FEATURE_IBRS))) return true; best = kvm_find_cpuid_entry(vcpu, 7, 0); - return best && (best->edx & bit(X86_FEATURE_SPEC_CTRL)); + return best && (best->edx & (bit(X86_FEATURE_SPEC_CTRL) | bit(X86_FEATURE_SPEC_CTRL_SSBD))); } static inline bool guest_cpuid_has_arch_capabilities(struct kvm_vcpu *vcpu) diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index f86303592768..9b3ac8c54a59 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -3090,7 +3090,7 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) break; case MSR_IA32_SPEC_CTRL: if (!msr_info->host_initiated && - !guest_cpuid_has_ibrs(vcpu)) + !guest_cpuid_has_spec_ctrl(vcpu)) return 1; msr_info->data = svm->spec_ctrl; @@ -3171,7 +3171,7 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr) break; case MSR_IA32_SPEC_CTRL: if (!msr->host_initiated && - !guest_cpuid_has_ibrs(vcpu)) + !guest_cpuid_has_spec_ctrl(vcpu)) return 1; /* The STIBP bit doesn't fault even if it's not advertised */ diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 0fffd247037b..ea2e36d85569 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2861,7 +2861,7 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) break; case MSR_IA32_SPEC_CTRL: if (!msr_info->host_initiated && - !guest_cpuid_has_ibrs(vcpu)) + !guest_cpuid_has_spec_ctrl(vcpu)) return 1; msr_info->data = to_vmx(vcpu)->spec_ctrl; @@ -2973,11 +2973,11 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) break; case MSR_IA32_SPEC_CTRL: if (!msr_info->host_initiated && - !guest_cpuid_has_ibrs(vcpu)) + !guest_cpuid_has_spec_ctrl(vcpu)) return 1; /* The STIBP bit doesn't fault even if it's not advertised */ - if (data & ~(SPEC_CTRL_IBRS | SPEC_CTRL_STIBP)) + if (data & ~(SPEC_CTRL_IBRS | SPEC_CTRL_STIBP | SPEC_CTRL_SSBD)) return 1; vmx->spec_ctrl = data; |