Commit 31be40b3 authored by Wei Yongjun's avatar Wei Yongjun Committed by Avi Kivity
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KVM: x86 emulator: put register operand write back to a function 



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

Signed-off-by: default avatarWei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 646bab55

arch/x86/kvm/emulate.c

+23 −32
Original line number Diff line number Diff line
@@ -1020,32 +1020,35 @@ static int load_segment_descriptor(struct x86_emulate_ctxt *ctxt, 
	return X86EMUL_PROPAGATE_FAULT;

}



static inline int writeback(struct x86_emulate_ctxt *ctxt,

			    struct x86_emulate_ops *ops)

static void write_register_operand(struct operand *op)

{

	int rc;

	struct decode_cache *c = &ctxt->decode;

	u32 err;



	switch (c->dst.type) {

	case OP_REG:

		/* The 4-byte case *is* correct:

		 * in 64-bit mode we zero-extend.

		 */

		switch (c->dst.bytes) {

	/* The 4-byte case *is* correct: in 64-bit mode we zero-extend. */

	switch (op->bytes) {

	case 1:

			*(u8 *)c->dst.addr.reg = (u8)c->dst.val;

		*(u8 *)op->addr.reg = (u8)op->val;

		break;

	case 2:

			*(u16 *)c->dst.addr.reg = (u16)c->dst.val;

		*(u16 *)op->addr.reg = (u16)op->val;

		break;

	case 4:

			*c->dst.addr.reg = (u32)c->dst.val;

			break;	/* 64b: zero-ext */

		*op->addr.reg = (u32)op->val;

		break;	/* 64b: zero-extend */

	case 8:

			*c->dst.addr.reg = c->dst.val;

		*op->addr.reg = op->val;

		break;

	}

}



static inline int writeback(struct x86_emulate_ctxt *ctxt,

			    struct x86_emulate_ops *ops)

{

	int rc;

	struct decode_cache *c = &ctxt->decode;

	u32 err;



	switch (c->dst.type) {

	case OP_REG:

		write_register_operand(&c->dst);

		break;

	case OP_MEM:

		if (c->lock_prefix)
@@ -2970,25 +2973,13 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) 
	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 */