Merge branch 'kvm-on-hv-msrbm-fix' into HEAD

[linux-2.6-microblaze.git] / arch / x86 / kvm / vmx / vmx.c

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index cee69d8..9d7f26e 100644 (file)
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2652,15 +2652,6 @@ int alloc_loaded_vmcs(struct loaded_vmcs *loaded_vmcs)
                if (!loaded_vmcs->msr_bitmap)
                        goto out_vmcs;
                memset(loaded_vmcs->msr_bitmap, 0xff, PAGE_SIZE);
-
-               if (IS_ENABLED(CONFIG_HYPERV) &&
-                   static_branch_unlikely(&enable_evmcs) &&
-                   (ms_hyperv.nested_features & HV_X64_NESTED_MSR_BITMAP)) {
-                       struct hv_enlightened_vmcs *evmcs =
-                               (struct hv_enlightened_vmcs *)loaded_vmcs->vmcs;
-
-                       evmcs->hv_enlightenments_control.msr_bitmap = 1;
-               }
        }
 
        memset(&loaded_vmcs->host_state, 0, sizeof(struct vmcs_host_state));
@@ -6851,6 +6842,19 @@ static int vmx_create_vcpu(struct kvm_vcpu *vcpu)
        if (err < 0)
                goto free_pml;
 
+       /*
+        * Use Hyper-V 'Enlightened MSR Bitmap' feature when KVM runs as a
+        * nested (L1) hypervisor and Hyper-V in L0 supports it. Enable the
+        * feature only for vmcs01, KVM currently isn't equipped to realize any
+        * performance benefits from enabling it for vmcs02.
+        */
+       if (IS_ENABLED(CONFIG_HYPERV) && static_branch_unlikely(&enable_evmcs) &&
+           (ms_hyperv.nested_features & HV_X64_NESTED_MSR_BITMAP)) {
+               struct hv_enlightened_vmcs *evmcs = (void *)vmx->vmcs01.vmcs;
+
+               evmcs->hv_enlightenments_control.msr_bitmap = 1;
+       }
+
        /* The MSR bitmap starts with all ones */
        bitmap_fill(vmx->shadow_msr_intercept.read, MAX_POSSIBLE_PASSTHROUGH_MSRS);
        bitmap_fill(vmx->shadow_msr_intercept.write, MAX_POSSIBLE_PASSTHROUGH_MSRS);