KVM: nVMX: Refactor handle_vmwrite

Refactor existent code so we re-use vmcs12_write_any to copy fields from the
shadow vmcs specified by the link pointer (used by the processor,
implementation-specific) to the VMCS12 software format used by L0 to hold
the fields in L1 memory address space.

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, 28 insertions, 24 deletions

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 7dc599630430..1ee63cae82cd 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -5842,6 +5842,33 @@ static inline bool vmcs12_read_any(struct kvm_vcpu *vcpu,
         }
 }
 
+
+static inline bool vmcs12_write_any(struct kvm_vcpu *vcpu,
+                                    unsigned long field, u64 field_value){
+        short offset = vmcs_field_to_offset(field);
+        char *p = ((char *) get_vmcs12(vcpu)) + offset;
+        if (offset < 0)
+                return false;
+
+        switch (vmcs_field_type(field)) {
+        case VMCS_FIELD_TYPE_U16:
+                *(u16 *)p = field_value;
+                return true;
+        case VMCS_FIELD_TYPE_U32:
+                *(u32 *)p = field_value;
+                return true;
+        case VMCS_FIELD_TYPE_U64:
+                *(u64 *)p = field_value;
+                return true;
+        case VMCS_FIELD_TYPE_NATURAL_WIDTH:
+                *(natural_width *)p = field_value;
+                return true;
+        default:
+                return false; /* can never happen. */
+        }
+
+}
+
 /*
  * VMX instructions which assume a current vmcs12 (i.e., that VMPTRLD was
  * used before) all generate the same failure when it is missing.
@@ -5906,8 +5933,6 @@ static int handle_vmwrite(struct kvm_vcpu *vcpu)
         gva_t gva;
         unsigned long exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
         u32 vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO);
-        char *p;
-        short offset;
         /* The value to write might be 32 or 64 bits, depending on L1's long
          * mode, and eventually we need to write that into a field of several
          * possible lengths. The code below first zero-extends the value to 64
@@ -5944,28 +5969,7 @@ static int handle_vmwrite(struct kvm_vcpu *vcpu)
                 return 1;
         }
 
-        offset = vmcs_field_to_offset(field);
-        if (offset < 0) {
-                nested_vmx_failValid(vcpu, VMXERR_UNSUPPORTED_VMCS_COMPONENT);
-                skip_emulated_instruction(vcpu);
-                return 1;
-        }
-        p = ((char *) get_vmcs12(vcpu)) + offset;
-
-        switch (vmcs_field_type(field)) {
-        case VMCS_FIELD_TYPE_U16:
-                *(u16 *)p = field_value;
-                break;
-        case VMCS_FIELD_TYPE_U32:
-                *(u32 *)p = field_value;
-                break;
-        case VMCS_FIELD_TYPE_U64:
-                *(u64 *)p = field_value;
-                break;
-        case VMCS_FIELD_TYPE_NATURAL_WIDTH:
-                *(natural_width *)p = field_value;
-                break;
-        default:
+        if (!vmcs12_write_any(vcpu, field, field_value)) {
                 nested_vmx_failValid(vcpu, VMXERR_UNSUPPORTED_VMCS_COMPONENT);
                 skip_emulated_instruction(vcpu);
                 return 1;