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KVM: x86 emulator: put register operand write back to a function

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

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Wei Yongjun 2010-08-17 09:17:30 +08:00 committed by Avi Kivity
parent 646bab55a2
commit 31be40b398
1 changed files with 23 additions and 32 deletions
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55
arch/x86/kvm/emulate.c
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@ -1020,6 +1020,25 @@ exception:
return X86EMUL_PROPAGATE_FAULT; 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, static inline int writeback(struct x86_emulate_ctxt *ctxt,
struct x86_emulate_ops *ops) struct x86_emulate_ops *ops)
{ {
@ -1029,23 +1048,7 @@ static inline int writeback(struct x86_emulate_ctxt *ctxt,
switch (c->dst.type) { switch (c->dst.type) {
case OP_REG: case OP_REG:
/* The 4-byte case *is* correct: write_register_operand(&c->dst);
* 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;
}
break; break;
case OP_MEM: case OP_MEM:
if (c->lock_prefix) if (c->lock_prefix)
@ -2970,25 +2973,13 @@ special_insn:
case 0x86 ... 0x87: /* xchg */ case 0x86 ... 0x87: /* xchg */
xchg: xchg:
/* Write back the register source. */ /* Write back the register source. */
switch (c->dst.bytes) { c->src.val = c->dst.val;
case 1: write_register_operand(&c->src);
*(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;
}
/* /*
* Write back the memory destination with implicit LOCK * Write back the memory destination with implicit LOCK
* prefix. * prefix.
*/ */
c->dst.val = c->src.val; c->dst.val = c->src.orig_val;
c->lock_prefix = 1; c->lock_prefix = 1;
break; break;
case 0x88 ... 0x8b: /* mov */ case 0x88 ... 0x8b: /* mov */