diff options
| author | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2018-04-25 22:04:25 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-05-22 16:58:00 +0200 |
| commit | 99318eca2c7ab3250b9614043b9ac6077ff2cb46 (patch) | |
| tree | 70c0ec28f8ef6fcef30358433a0b3be0b6daf8a9 | |
| parent | f854434b37bbf8953900226acd6139081f60d3da (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>
| -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 93f924de06cf..a9409f06ddc9 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -382,7 +382,7 @@ 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(RDS) | 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 d1beb7156704..24187d07c2cf 100644 --- a/arch/x86/kvm/cpuid.h +++ b/arch/x86/kvm/cpuid.h @@ -171,7 +171,7 @@ 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; @@ -179,7 +179,7 @@ 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_RDS))); } 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 eeb8cd3193ea..57b886bf5ac5 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -3545,7 +3545,7 @@ 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; @@ -3643,7 +3643,7 @@ 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 266db0b2e138..67ed4e9f9e5b 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -3020,7 +3020,7 @@ 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; @@ -3137,11 +3137,11 @@ 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_RDS)) return 1; vmx->spec_ctrl = data; |