[PATCH 1/2 v4] KVM: x86 emulator: put register operand write back to a function

[PATCH 1/2 v4] KVM: x86 emulator: put register operand write back to a function

[Wei Yongjun]

Introduce function write_register_operand() to write back the
register operand.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
---
 arch/x86/kvm/emulate.c |   55 ++++++++++++++++++++---------------------------
 1 files changed, 23 insertions(+), 32 deletions(-)

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index c476a67..d690daf 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -1020,6 +1020,25 @@ exception:
 	return X86EMUL_PROPAGATE_FAULT;
 }
 
+static void write_register_operand(struct operand *op)
+{
+	/* The 4-byte case *is* correct: in 64-bit mode we zero-extend. */
+	switch (op->bytes) {
+	case 1:
+		*(u8 *)op->addr.reg = (u8)op->val;
+		break;
+	case 2:
+		*(u16 *)op->addr.reg = (u16)op->val;
+		break;
+	case 4:
+		*op->addr.reg = (u32)op->val;
+		break;	/* 64b: zero-extend */
+	case 8:
+		*op->addr.reg = op->val;
+		break;
+	}
+}
+
 static inline int writeback(struct x86_emulate_ctxt *ctxt,
 			    struct x86_emulate_ops *ops)
 {
@@ -1029,23 +1048,7 @@ static inline int writeback(struct x86_emulate_ctxt *ctxt,
 
 	switch (c->dst.type) {
 	case OP_REG:
-		/* The 4-byte case *is* correct:
-		 * in 64-bit mode we zero-extend.
-		 */
-		switch (c->dst.bytes) {
-		case 1:
-			*(u8 *)c->dst.addr.reg = (u8)c->dst.val;
-			break;
-		case 2:
-			*(u16 *)c->dst.addr.reg = (u16)c->dst.val;
-			break;
-		case 4:
-			*c->dst.addr.reg = (u32)c->dst.val;
-			break;	/* 64b: zero-ext */
-		case 8:
-			*c->dst.addr.reg = c->dst.val;
-			break;
-		}
+		write_register_operand(&c->dst);
 		break;
 	case OP_MEM:
 		if (c->lock_prefix)
@@ -2971,25 +2974,13 @@ special_insn:
 	case 0x86 ... 0x87:	/* xchg */
 	xchg:
 		/* Write back the register source. */
-		switch (c->dst.bytes) {
-		case 1:
-			*(u8 *) c->src.addr.reg = (u8) c->dst.val;
-			break;
-		case 2:
-			*(u16 *) c->src.addr.reg = (u16) c->dst.val;
-			break;
-		case 4:
-			*c->src.addr.reg = (u32) c->dst.val;
-			break;	/* 64b reg: zero-extend */
-		case 8:
-			*c->src.addr.reg = c->dst.val;
-			break;
-		}
+		c->src.val = c->dst.val;
+		write_register_operand(&c->src);
 		/*
 		 * Write back the memory destination with implicit LOCK
 		 * prefix.
 		 */
-		c->dst.val = c->src.val;
+		c->dst.val = c->src.orig_val;
 		c->lock_prefix = 1;
 		break;
 	case 0x88 ... 0x8b:	/* mov */
-- 
1.7.0.4

[PATCH 2/2 v4] KVM: x86 emulator: add XADD instruction emulation

[Wei Yongjun]

Add XADD instruction emulation (opcode 0x0f 0xc0~0xc1)

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
---
 arch/x86/kvm/emulate.c |    9 ++++++++-
 1 files changed, 8 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index d690daf..41ca98b 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -2386,7 +2386,8 @@ static struct opcode twobyte_table[256] = {
 	D(DstReg | SrcMem | ModRM), D(DstReg | SrcMem | ModRM),
 	D(ByteOp | DstReg | SrcMem | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
 	/* 0xC0 - 0xCF */
-	N, N, N, D(DstMem | SrcReg | ModRM | Mov),
+	D(ByteOp | DstMem | SrcReg | ModRM | Lock), D(DstMem | SrcReg | ModRM | Lock),
+	N, D(DstMem | SrcReg | ModRM | Mov),
 	N, N, N, GD(0, &group9),
 	N, N, N, N, N, N, N, N,
 	/* 0xD0 - 0xDF */
@@ -3532,6 +3533,12 @@ twobyte_insn:
 		c->dst.val = (c->d & ByteOp) ? (s8) c->src.val :
 							(s16) c->src.val;
 		break;
+	case 0xc0 ... 0xc1:	/* xadd */
+		emulate_2op_SrcV("add", c->src, c->dst, ctxt->eflags);
+		/* Write back the register source. */
+		c->src.val = c->dst.orig_val;
+		write_register_operand(&c->src);
+		break;
 	case 0xc3:		/* movnti */
 		c->dst.bytes = c->op_bytes;
 		c->dst.val = (c->op_bytes == 4) ? (u32) c->src.val :
-- 
1.7.0.4

Re: [PATCH 1/2 v4] KVM: x86 emulator: put register operand write back to a function

[Avi Kivity]

 On 08/17/2010 04:17 AM, Wei Yongjun wrote:
> Introduce function write_register_operand() to write back the
> register operand.

Applied, thanks.

-- 
error compiling committee.c: too many arguments to function