Use the new MSR feature framework to expose the ARCH_CAPABILITIES MSR to
userspace. This way, userspace can access the capabilities even if it
does not have the permissions to read MSRs.
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/kvm/vmx.c | 12 +++++++++++-
arch/x86/kvm/x86.c | 1 +
2 files changed, 12 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 130fca0ea1bf..99689061e11e 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -3228,7 +3228,17 @@ static inline bool vmx_feature_control_msr_valid(struct kvm_vcpu *vcpu,
static int vmx_get_msr_feature(struct kvm_msr_entry *msr)
{
- return 1;
+ switch (msr->index) {
+ case MSR_IA32_ARCH_CAPABILITIES:
+ if (!boot_cpu_has(X86_FEATURE_ARCH_CAPABILITIES))
+ return 1;
+ rdmsrl(msr->index, msr->data);
+ break;
+ default:
+ return 1;
+ }
+
+ return 0;
}
/*
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 54b4ed55945b..e9a8cc9e3b2b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1054,6 +1054,7 @@ bool kvm_rdpmc(struct kvm_vcpu *vcpu)
* can be used by a hypervisor to validate requested CPU features.
*/
static u32 msr_based_features[] = {
+ MSR_IA32_ARCH_CAPABILITIES,
MSR_F10H_DECFG,
};
--
1.8.3.1
