static int do_fetch_insn_byte(struct x86_emulate_ctxt *ctxt,
struct x86_emulate_ops *ops,
- unsigned long linear, u8 *dest)
+ unsigned long eip, u8 *dest)
{
struct fetch_cache *fc = &ctxt->decode.fetch;
int rc;
- int size;
+ int size, cur_size;
- if (linear < fc->start || linear >= fc->end) {
- size = min(15UL, PAGE_SIZE - offset_in_page(linear));
- rc = ops->fetch(linear, fc->data, size, ctxt->vcpu, NULL);
+ if (eip == fc->end) {
+ cur_size = fc->end - fc->start;
+ size = min(15UL - cur_size, PAGE_SIZE - offset_in_page(eip));
+ rc = ops->fetch(ctxt->cs_base + eip, fc->data + cur_size,
+ size, ctxt->vcpu, NULL);
if (rc != X86EMUL_CONTINUE)
return rc;
- fc->start = linear;
- fc->end = linear + size;
+ fc->end += size;
}
- *dest = fc->data[linear - fc->start];
+ *dest = fc->data[eip - fc->start];
return X86EMUL_CONTINUE;
}
/* x86 instructions are limited to 15 bytes. */
if (eip + size - ctxt->eip > 15)
return X86EMUL_UNHANDLEABLE;
- eip += ctxt->cs_base;
while (size--) {
rc = do_fetch_insn_byte(ctxt, ops, eip++, dest++);
if (rc != X86EMUL_CONTINUE)
/* Shadow copy of register state. Committed on successful emulation. */
memset(c, 0, sizeof(struct decode_cache));
c->eip = ctxt->eip;
+ c->fetch.start = c->fetch.end = c->eip;
ctxt->cs_base = seg_base(ctxt, VCPU_SREG_CS);
memcpy(c->regs, ctxt->vcpu->arch.regs, sizeof c->regs);