[PATCH 09/13] KVM: x86 emulator: add Undefined decode flag

[Avi Kivity <avi@redhat.com>]

Add a decode flag to indicate the instruction is invalid.  Will come in useful
later, when we mix decode bits from the opcode and group table.

Signed-off-by: Avi Kivity <avi@redhat.com>
---
 arch/x86/kvm/emulate.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 434ac8f..9a2db88 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -84,6 +84,7 @@
 #define GroupDual   (1<<15)     /* Alternate decoding of mod == 3 */
 #define GroupMask   0x0f        /* Group number stored in bits 0:3 */
 /* Misc flags */
+#define Undefined   (1<<25) /* No Such Instruction */
 #define Lock        (1<<26) /* lock prefix is allowed for the instruction */
 #define Priv        (1<<27) /* instruction generates #GP if current CPL != 0 */
 #define No64	    (1<<28)
@@ -1065,7 +1066,7 @@ done_prefixes:
 	}
 
 	/* Unrecognised? */
-	if (c->d == 0) {
+	if (c->d == 0 || (c->d & Undefined)) {
 		DPRINTF("Cannot emulate %02x\n", c->b);
 		return -1;
 	}
-- 
1.7.1