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>

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 7dc5996..1ee63ca 100644 (file)
--- 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;