1 files changed, 45 insertions, 0 deletions

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 628d012112f5..8dc59aaab3db 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -718,6 +718,7 @@ static void vmx_get_segment(struct kvm_vcpu *vcpu,
 static bool guest_state_valid(struct kvm_vcpu *vcpu);
 static u32 vmx_segment_access_rights(struct kvm_segment *var);
 static void vmx_sync_pir_to_irr_dummy(struct kvm_vcpu *vcpu);
+static void copy_vmcs12_to_shadow(struct vcpu_vmx *vmx);
 static void copy_shadow_to_vmcs12(struct vcpu_vmx *vmx);
 
 static DEFINE_PER_CPU(struct vmcs *, vmxarea);
@@ -5930,6 +5931,50 @@ static void copy_shadow_to_vmcs12(struct vcpu_vmx *vmx)
         vmcs_load(vmx->loaded_vmcs->vmcs);
 }
 
+static void copy_vmcs12_to_shadow(struct vcpu_vmx *vmx)
+{
+        unsigned long *fields[] = {
+                (unsigned long *)shadow_read_write_fields,
+                (unsigned long *)shadow_read_only_fields
+        };
+        int num_lists =  ARRAY_SIZE(fields);
+        int max_fields[] = {
+                max_shadow_read_write_fields,
+                max_shadow_read_only_fields
+        };
+        int i, q;
+        unsigned long field;
+        u64 field_value = 0;
+        struct vmcs *shadow_vmcs = vmx->nested.current_shadow_vmcs;
+
+        vmcs_load(shadow_vmcs);
+
+        for (q = 0; q < num_lists; q++) {
+                for (i = 0; i < max_fields[q]; i++) {
+                        field = fields[q][i];
+                        vmcs12_read_any(&vmx->vcpu, field, &field_value);
+
+                        switch (vmcs_field_type(field)) {
+                        case VMCS_FIELD_TYPE_U16:
+                                vmcs_write16(field, (u16)field_value);
+                                break;
+                        case VMCS_FIELD_TYPE_U32:
+                                vmcs_write32(field, (u32)field_value);
+                                break;
+                        case VMCS_FIELD_TYPE_U64:
+                                vmcs_write64(field, (u64)field_value);
+                                break;
+                        case VMCS_FIELD_TYPE_NATURAL_WIDTH:
+                                vmcs_writel(field, (long)field_value);
+                                break;
+                        }
+                }
+        }
+
+        vmcs_clear(shadow_vmcs);
+        vmcs_load(vmx->loaded_vmcs->vmcs);
+}
+
 /*
  * VMX instructions which assume a current vmcs12 (i.e., that VMPTRLD was
  * used before) all generate the same failure when it is missing.