2 files changed, 31 insertions, 7 deletions

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 183dc72b2523..e37b2a33fd24 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -373,6 +373,7 @@ struct nested_vmx {
          * we must keep them pinned while L2 runs.
          */
         struct page *apic_access_page;
+        u64 msr_ia32_feature_control;
 };
 
 #define POSTED_INTR_ON  0
@@ -2282,8 +2283,11 @@ static int vmx_get_vmx_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata)
 
         switch (msr_index) {
         case MSR_IA32_FEATURE_CONTROL:
-                *pdata = 0;
-                break;
+                if (nested_vmx_allowed(vcpu)) {
+                        *pdata = to_vmx(vcpu)->nested.msr_ia32_feature_control;
+                        break;
+                }
+                return 0;
         case MSR_IA32_VMX_BASIC:
                 /*
                  * This MSR reports some information about VMX support. We
@@ -2356,14 +2360,24 @@ static int vmx_get_vmx_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata)
         return 1;
 }
 
-static int vmx_set_vmx_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data)
+static int vmx_set_vmx_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 {
+        u32 msr_index = msr_info->index;
+        u64 data = msr_info->data;
+        bool host_initialized = msr_info->host_initiated;
+
         if (!nested_vmx_allowed(vcpu))
                 return 0;
 
-        if (msr_index == MSR_IA32_FEATURE_CONTROL)
-                /* TODO: the right thing. */
+        if (msr_index == MSR_IA32_FEATURE_CONTROL) {
+                if (!host_initialized &&
+                                to_vmx(vcpu)->nested.msr_ia32_feature_control
+                                & FEATURE_CONTROL_LOCKED)
+                        return 0;
+                to_vmx(vcpu)->nested.msr_ia32_feature_control = data;
                 return 1;
+        }
+
         /*
          * No need to treat VMX capability MSRs specially: If we don't handle
          * them, handle_wrmsr will #GP(0), which is correct (they are readonly)
@@ -2494,7 +2508,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
                         return 1;
                 /* Otherwise falls through */
         default:
-                if (vmx_set_vmx_msr(vcpu, msr_index, data))
+                if (vmx_set_vmx_msr(vcpu, msr_info))
                         break;
                 msr = find_msr_entry(vmx, msr_index);
                 if (msr) {
@@ -5622,6 +5636,8 @@ static int handle_vmon(struct kvm_vcpu *vcpu)
         struct kvm_segment cs;
         struct vcpu_vmx *vmx = to_vmx(vcpu);
         struct vmcs *shadow_vmcs;
+        const u64 VMXON_NEEDED_FEATURES = FEATURE_CONTROL_LOCKED
+                | FEATURE_CONTROL_VMXON_ENABLED_OUTSIDE_SMX;
 
         /* The Intel VMX Instruction Reference lists a bunch of bits that
          * are prerequisite to running VMXON, most notably cr4.VMXE must be
@@ -5650,6 +5666,13 @@ static int handle_vmon(struct kvm_vcpu *vcpu)
                 skip_emulated_instruction(vcpu);
                 return 1;
         }
+
+        if ((vmx->nested.msr_ia32_feature_control & VMXON_NEEDED_FEATURES)
+                        != VMXON_NEEDED_FEATURES) {
+                kvm_inject_gp(vcpu, 0);
+                return 1;
+        }
+
         if (enable_shadow_vmcs) {
                 shadow_vmcs = alloc_vmcs();
                 if (!shadow_vmcs)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index abbcaa7f6e8f..d2caeb9e592f 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -850,7 +850,8 @@ static u32 msrs_to_save[] = {
 #ifdef CONFIG_X86_64
         MSR_CSTAR, MSR_KERNEL_GS_BASE, MSR_SYSCALL_MASK, MSR_LSTAR,
 #endif
-        MSR_IA32_TSC, MSR_IA32_CR_PAT, MSR_VM_HSAVE_PA
+        MSR_IA32_TSC, MSR_IA32_CR_PAT, MSR_VM_HSAVE_PA,
+        MSR_IA32_FEATURE_CONTROL
 };
 
 static unsigned num_msrs_to_save;