diff options
| author | Haozhong Zhang <haozhong.zhang@intel.com> | 2016-06-22 14:59:55 +0800 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2016-06-23 19:17:29 +0200 |
| commit | 37e4c997dadf713d5b9cb88a801eb38d61a2aefc (patch) | |
| tree | 612b468041a6d3fc5234716d1869b38c94f7ada9 /arch/x86/kvm/vmx.c | |
| parent | 3b84080b9512bcacad3805f345fb8f092c8d3a7d (diff) | |
KVM: VMX: validate individual bits of guest MSR_IA32_FEATURE_CONTROL
KVM currently does not check the value written to guest
MSR_IA32_FEATURE_CONTROL, though bits corresponding to disabled features
may be set. This patch makes KVM to validate individual bits written to
guest MSR_IA32_FEATURE_CONTROL according to enabled features.
Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/vmx.c')
| -rw-r--r-- | arch/x86/kvm/vmx.c | 25 |
1 files changed, 24 insertions, 1 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index ad66978281c1..0a3ccb073bb4 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -612,7 +612,13 @@ struct vcpu_vmx { u32 guest_pkru; u32 host_pkru; + /* + * Only bits masked by msr_ia32_feature_control_valid_bits can be set in + * msr_ia32_feature_control. FEATURE_CONTROL_LOCKED is always included + * in msr_ia32_feature_control_valid_bits. + */ u64 msr_ia32_feature_control; + u64 msr_ia32_feature_control_valid_bits; }; enum segment_cache_field { @@ -2929,6 +2935,14 @@ static int vmx_get_vmx_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata) return 0; } +static inline bool vmx_feature_control_msr_valid(struct kvm_vcpu *vcpu, + uint64_t val) +{ + uint64_t valid_bits = to_vmx(vcpu)->msr_ia32_feature_control_valid_bits; + + return !(val & ~valid_bits); +} + /* * Reads an msr value (of 'msr_index') into 'pdata'. * Returns 0 on success, non-0 otherwise. @@ -3062,7 +3076,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) ret = kvm_set_msr_common(vcpu, msr_info); break; case MSR_IA32_FEATURE_CONTROL: - if (!nested_vmx_allowed(vcpu) || + if (!vmx_feature_control_msr_valid(vcpu, data) || (to_vmx(vcpu)->msr_ia32_feature_control & FEATURE_CONTROL_LOCKED && !msr_info->host_initiated)) return 1; @@ -9055,6 +9069,8 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id) goto free_vmcs; } + vmx->msr_ia32_feature_control_valid_bits = FEATURE_CONTROL_LOCKED; + return &vmx->vcpu; free_vmcs: @@ -9202,6 +9218,13 @@ static void vmx_cpuid_update(struct kvm_vcpu *vcpu) vmx->nested.nested_vmx_secondary_ctls_high &= ~SECONDARY_EXEC_PCOMMIT; } + + if (nested_vmx_allowed(vcpu)) + to_vmx(vcpu)->msr_ia32_feature_control_valid_bits |= + FEATURE_CONTROL_VMXON_ENABLED_OUTSIDE_SMX; + else + to_vmx(vcpu)->msr_ia32_feature_control_valid_bits &= + ~FEATURE_CONTROL_VMXON_ENABLED_OUTSIDE_SMX; } static void vmx_set_supported_cpuid(u32 func, struct kvm_cpuid_entry2 *entry) |