KVM: nVMX: Copy processor-specific shadow-vmcs to VMCS12

Introduce a function used to copy fields from the processor-specific shadow
vmcs to the software controlled VMCS12

Signed-off-by: Abel Gordon <abelg@il.ibm.com>
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>

1 files changed, 35 insertions, 0 deletions

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index ad3957e5f2e8..628d012112f5 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_shadow_to_vmcs12(struct vcpu_vmx *vmx);
 
 static DEFINE_PER_CPU(struct vmcs *, vmxarea);
 static DEFINE_PER_CPU(struct vmcs *, current_vmcs);
@@ -5895,6 +5896,40 @@ static inline bool vmcs12_write_any(struct kvm_vcpu *vcpu,
 
 }
 
+static void copy_shadow_to_vmcs12(struct vcpu_vmx *vmx)
+{
+        int i;
+        unsigned long field;
+        u64 field_value;
+        struct vmcs *shadow_vmcs = vmx->nested.current_shadow_vmcs;
+        unsigned long *fields = (unsigned long *)shadow_read_write_fields;
+        int num_fields = max_shadow_read_write_fields;
+
+        vmcs_load(shadow_vmcs);
+
+        for (i = 0; i < num_fields; i++) {
+                field = fields[i];
+                switch (vmcs_field_type(field)) {
+                case VMCS_FIELD_TYPE_U16:
+                        field_value = vmcs_read16(field);
+                        break;
+                case VMCS_FIELD_TYPE_U32:
+                        field_value = vmcs_read32(field);
+                        break;
+                case VMCS_FIELD_TYPE_U64:
+                        field_value = vmcs_read64(field);
+                        break;
+                case VMCS_FIELD_TYPE_NATURAL_WIDTH:
+                        field_value = vmcs_readl(field);
+                        break;
+                }
+                vmcs12_write_any(&vmx->vcpu, field, field_value);
+        }
+
+        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.