Commit 3c118e24 authored by Avi Kivity's avatar Avi Kivity
Browse files

KVM: x86 emulator: Extract the common code of SrcReg and DstReg 



Share the common parts of SrcReg and DstReg decoding.

Signed-off-by: default avatarAvi Kivity <avi@qumranet.com>
parent de7d789a

drivers/kvm/x86_emulate.c

+31 −49
Original line number Diff line number Diff line
@@ -520,6 +520,34 @@ static int test_cc(unsigned int condition, unsigned int flags) 
	return (!!rc ^ (condition & 1));

}



static void decode_register_operand(struct operand *op,

				    struct decode_cache *c,

				    int highbyte_regs,

				    int inhibit_bytereg)

{

	op->type = OP_REG;

	if ((c->d & ByteOp) && !inhibit_bytereg) {

		op->ptr = decode_register(c->modrm_reg, c->regs, highbyte_regs);

		op->val = *(u8 *)op->ptr;

		op->bytes = 1;

	} else {

		op->ptr = decode_register(c->modrm_reg, c->regs, 0);

		op->bytes = c->op_bytes;

		switch (op->bytes) {

		case 2:

			op->val = *(u16 *)op->ptr;

			break;

		case 4:

			op->val = *(u32 *)op->ptr;

			break;

		case 8:

			op->val = *(u64 *) op->ptr;

			break;

		}

	}

	op->orig_val = op->val;

}



int

x86_decode_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)

{
@@ -809,31 +837,7 @@ x86_decode_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) 
	case SrcNone:

		break;

	case SrcReg:

		c->src.type = OP_REG;

		if (c->d & ByteOp) {

			c->src.ptr =

				decode_register(c->modrm_reg, c->regs,

						  (rex_prefix == 0));

			c->src.val = c->src.orig_val = *(u8 *)c->src.ptr;

			c->src.bytes = 1;

		} else {

			c->src.ptr =

			    decode_register(c->modrm_reg, c->regs, 0);

			switch ((c->src.bytes = c->op_bytes)) {

			case 2:

				c->src.val = c->src.orig_val =

						       *(u16 *) c->src.ptr;

				break;

			case 4:

				c->src.val = c->src.orig_val =

						       *(u32 *) c->src.ptr;

				break;

			case 8:

				c->src.val = c->src.orig_val =

						       *(u64 *) c->src.ptr;

				break;

			}

		}

		decode_register_operand(&c->src, c, rex_prefix == 0, 0);

		break;

	case SrcMem16:

		c->src.bytes = 2;
@@ -891,30 +895,8 @@ x86_decode_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) 
		/* Special instructions do their own operand decoding. */

		return 0;

	case DstReg:

		c->dst.type = OP_REG;

		if ((c->d & ByteOp)

		    && !(c->twobyte &&

			(c->b == 0xb6 || c->b == 0xb7))) {

			c->dst.ptr =

				decode_register(c->modrm_reg, c->regs,

						  (rex_prefix == 0));

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

			c->dst.bytes = 1;

		} else {

			c->dst.ptr =

			    decode_register(c->modrm_reg, c->regs, 0);

			switch ((c->dst.bytes = c->op_bytes)) {

			case 2:

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

				break;

			case 4:

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

				break;

			case 8:

				c->dst.val = *(u64 *)c->dst.ptr;

				break;

			}

		}

		decode_register_operand(&c->dst, c, rex_prefix == 0,

			 c->twobyte && (c->b == 0xb6 || c->b == 0xb7));

		break;

	case DstMem:

		if ((c->d & ModRM) && c->modrm_mod == 3) {