When running test 5 in Memtest86+ v1.65, I got a "this opcode is not

supported", so I decided to add it. It's a compare operation, and it's
just the opposite of the already supported one (opcode 0x39), so it's
nothing spectacular. Why there's a page-fault when this instruction gets
executed, I haven't got a clue, but I have a feeling that Memtest86 is
doing something wrong :-( However, this fix may help some other code to
run too...

With this, Test 5 passes all the way through without crashing. I did see
some occassional memory errors in some other tests, and I'm not 100%
sure whether those are caused by the system or they are "real" memory
errors. At some time in the future I may get round to memory testing my
target system...

Signed off by: Mats Petersson (mats.petersson@amd.com).=20

diff --git a/xen/arch/x86/hvm/platform.c b/xen/arch/x86/hvm/platform.c
index c36360bcb3b23374271f3a86bd4dfc6cbd6ce28b..1e78470d344843449834d86196fe496d55e8357e 100644 (file)
--- a/xen/arch/x86/hvm/platform.c
+++ b/xen/arch/x86/hvm/platform.c
@@ -401,6 +401,11 @@ static int hvm_decode(int realmode, unsigned char *opcode, struct instruction *i
         GET_OP_SIZE_FOR_NONEBYTE(instr->op_size);
         return reg_mem(instr->op_size, opcode, instr, rex);
 
+    case 0x3B: /* cmp m32/16, r32/16 */
+        instr->instr = INSTR_CMP;
+        GET_OP_SIZE_FOR_NONEBYTE(instr->op_size);
+        return mem_reg(instr->op_size, opcode, instr, rex);
+
     case 0x80:
     case 0x81:
         {