KVM: x86 emulator: Group decoding for groups 4 and 5

Add group decoding support for opcode 0xfe (group 4) and 0xff (group 5).
Signed-off-by: Avi Kivity <avi@qumranet.com>

arch/x86/kvm/x86_emulate.c

@@ -70,7 +70,7 @@
 #define GroupMask   0xff        /* Group number stored in bits 0:7 */
 
 enum {
-	Group1A, Group3_Byte, Group3,
+	Group1A, Group3_Byte, Group3, Group4, Group5,
 };
 
 static u16 opcode_table[256] = {
@@ -174,7 +174,7 @@ static u16 opcode_table[256] = {
 	ImplicitOps, ImplicitOps, Group | Group3_Byte, Group | Group3,
 	/* 0xF8 - 0xFF */
 	ImplicitOps, 0, ImplicitOps, ImplicitOps,
-	0, 0, ByteOp | DstMem | SrcNone | ModRM, DstMem | SrcNone | ModRM
+	0, 0, Group | Group4, Group | Group5,
 };
 
 static u16 twobyte_table[256] = {
@@ -246,6 +246,12 @@ static u16 group_table[] = {
 	DstMem | SrcImm | ModRM | SrcImm, 0,
 	DstMem | SrcNone | ModRM, ByteOp | DstMem | SrcNone | ModRM,
 	0, 0, 0, 0,
+	[Group4*8] =
+	ByteOp | DstMem | SrcNone | ModRM, ByteOp | DstMem | SrcNone | ModRM,
+	0, 0, 0, 0, 0, 0,
+	[Group5*8] =
+	DstMem | SrcNone | ModRM, DstMem | SrcNone | ModRM, 0, 0,
+	SrcMem | ModRM, 0, SrcMem | ModRM | Stack, 0,
 };
 
 static u16 group2_table[] = {
@@ -1097,7 +1103,6 @@ static inline int emulate_grp45(struct x86_emulate_ctxt *ctxt,
 			       struct x86_emulate_ops *ops)
 {
 	struct decode_cache *c = &ctxt->decode;
-	int rc;
 
 	switch (c->modrm_reg) {
 	case 0:	/* inc */
@@ -1107,36 +1112,11 @@ static inline int emulate_grp45(struct x86_emulate_ctxt *ctxt,
 		emulate_1op("dec", c->dst, ctxt->eflags);
 		break;
 	case 4: /* jmp abs */
-		if (c->b == 0xff)
-			c->eip = c->dst.val;
-		else {
-			DPRINTF("Cannot emulate %02x\n", c->b);
-			return X86EMUL_UNHANDLEABLE;
-		}
+		c->eip = c->src.val;
 		break;
 	case 6:	/* push */
-
-		/* 64-bit mode: PUSH always pushes a 64-bit operand. */
-
-		if (ctxt->mode == X86EMUL_MODE_PROT64) {
-			c->dst.bytes = 8;
-			rc = ops->read_std((unsigned long)c->dst.ptr,
-					   &c->dst.val, 8, ctxt->vcpu);
-			if (rc != 0)
-				return rc;
-		}
-		register_address_increment(c->regs[VCPU_REGS_RSP],
-					   -c->dst.bytes);
-		rc = ops->write_emulated(register_address(ctxt->ss_base,
-				    c->regs[VCPU_REGS_RSP]), &c->dst.val,
-				    c->dst.bytes, ctxt->vcpu);
-		if (rc != 0)
-			return rc;
-		c->dst.type = OP_NONE;
+		emulate_push(ctxt);
 		break;
-	default:
-		DPRINTF("Cannot emulate %02x\n", c->b);
-		return X86EMUL_UNHANDLEABLE;
 	}
 	return 0;
 }