diff options
| -rw-r--r-- | arch/x86/kvm/svm/svm.c | 2 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 2 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 38 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.h | 2 |
4 files changed, 24 insertions, 20 deletions
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 472544cf1de2..9b59e63567bb 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -2522,7 +2522,7 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr) !guest_cpuid_has(vcpu, X86_FEATURE_AMD_SSBD)) return 1; - if (data & ~kvm_spec_ctrl_valid_bits(vcpu)) + if (kvm_spec_ctrl_test_value(data)) return 1; svm->spec_ctrl = data; diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index c6e96e2ef4d6..0d526b32f041 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -2062,7 +2062,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL)) return 1; - if (data & ~kvm_spec_ctrl_valid_bits(vcpu)) + if (kvm_spec_ctrl_test_value(data)) return 1; vmx->spec_ctrl = data; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index c432a445cbbe..7f32169e8449 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -10693,28 +10693,32 @@ bool kvm_arch_no_poll(struct kvm_vcpu *vcpu) } EXPORT_SYMBOL_GPL(kvm_arch_no_poll); -u64 kvm_spec_ctrl_valid_bits(struct kvm_vcpu *vcpu) + +int kvm_spec_ctrl_test_value(u64 value) { - uint64_t bits = SPEC_CTRL_IBRS | SPEC_CTRL_STIBP | SPEC_CTRL_SSBD; + /* + * test that setting IA32_SPEC_CTRL to given value + * is allowed by the host processor + */ + + u64 saved_value; + unsigned long flags; + int ret = 0; - /* The STIBP bit doesn't fault even if it's not advertised */ - if (!guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL) && - !guest_cpuid_has(vcpu, X86_FEATURE_AMD_IBRS)) - bits &= ~(SPEC_CTRL_IBRS | SPEC_CTRL_STIBP); - if (!boot_cpu_has(X86_FEATURE_SPEC_CTRL) && - !boot_cpu_has(X86_FEATURE_AMD_IBRS)) - bits &= ~(SPEC_CTRL_IBRS | SPEC_CTRL_STIBP); + local_irq_save(flags); - if (!guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL_SSBD) && - !guest_cpuid_has(vcpu, X86_FEATURE_AMD_SSBD)) - bits &= ~SPEC_CTRL_SSBD; - if (!boot_cpu_has(X86_FEATURE_SPEC_CTRL_SSBD) && - !boot_cpu_has(X86_FEATURE_AMD_SSBD)) - bits &= ~SPEC_CTRL_SSBD; + if (rdmsrl_safe(MSR_IA32_SPEC_CTRL, &saved_value)) + ret = 1; + else if (wrmsrl_safe(MSR_IA32_SPEC_CTRL, value)) + ret = 1; + else + wrmsrl(MSR_IA32_SPEC_CTRL, saved_value); - return bits; + local_irq_restore(flags); + + return ret; } -EXPORT_SYMBOL_GPL(kvm_spec_ctrl_valid_bits); +EXPORT_SYMBOL_GPL(kvm_spec_ctrl_test_value); EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_exit); EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_fast_mmio); diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h index 224670d7c245..3308c3ccc0fd 100644 --- a/arch/x86/kvm/x86.h +++ b/arch/x86/kvm/x86.h @@ -368,7 +368,7 @@ static inline bool kvm_dr6_valid(u64 data) void kvm_load_guest_xsave_state(struct kvm_vcpu *vcpu); void kvm_load_host_xsave_state(struct kvm_vcpu *vcpu); -u64 kvm_spec_ctrl_valid_bits(struct kvm_vcpu *vcpu); +int kvm_spec_ctrl_test_value(u64 value); int kvm_valid_cr4(struct kvm_vcpu *vcpu, unsigned long cr4); bool kvm_vcpu_exit_request(struct kvm_vcpu *vcpu); |