From: Avi Kivity <avi@redhat.com>
Date: Mon, 26 Jul 2010 11:37:47 +0000 (+0300)
Subject: KVM: x86 emulator: add Undefined decode flag
X-Git-Tag: v2.6.37-rc1~142^2~311
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=047a4818094217a1323d8f31f9318ea2e142f745;p=linux-block.git

KVM: x86 emulator: add Undefined decode flag

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>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
---

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 61139e20b899..b1e3e8c2aff5 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;
 	}