KVM: x86 emulator: get rid of "restart" in emulation context.
x86_emulate_insn() will return 1 if instruction can be restarted
without re-entering a guest.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 3dcbc1d..ec35a71 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -437,7 +437,6 @@
ctxt->exception = vec;
ctxt->error_code = error;
ctxt->error_code_valid = valid;
- ctxt->restart = false;
}
static void emulate_gp(struct x86_emulate_ctxt *ctxt, int err)
@@ -2633,9 +2632,6 @@
struct opcode opcode, *g_mod012, *g_mod3;
struct operand memop = { .type = OP_NONE };
- /* we cannot decode insn before we complete previous rep insn */
- WARN_ON(ctxt->restart);
-
c->eip = ctxt->eip;
c->fetch.start = c->fetch.end = c->eip;
ctxt->cs_base = seg_base(ctxt, ops, VCPU_SREG_CS);
@@ -2985,10 +2981,8 @@
}
if (c->rep_prefix && (c->d & String)) {
- ctxt->restart = true;
/* All REP prefixes have the same first termination condition */
if (address_mask(c, c->regs[VCPU_REGS_RCX]) == 0) {
- ctxt->restart = false;
ctxt->eip = c->eip;
goto done;
}
@@ -3446,28 +3440,29 @@
struct read_cache *r = &ctxt->decode.io_read;
register_address_increment(c, &c->regs[VCPU_REGS_RCX], -1);
- if (string_insn_completed(ctxt))
- ctxt->restart = false;
- /*
- * Re-enter guest when pio read ahead buffer is empty or,
- * if it is not used, after each 1024 iteration.
- */
- else if ((r->end == 0 && !(c->regs[VCPU_REGS_RCX] & 0x3ff)) ||
- (r->end != 0 && r->end == r->pos)) {
- ctxt->restart = false;
- c->eip = ctxt->eip;
+ if (!string_insn_completed(ctxt)) {
+ /*
+ * Re-enter guest when pio read ahead buffer is empty
+ * or, if it is not used, after each 1024 iteration.
+ */
+ if ((r->end != 0 || c->regs[VCPU_REGS_RCX] & 0x3ff) &&
+ (r->end == 0 || r->end != r->pos)) {
+ /*
+ * Reset read cache. Usually happens before
+ * decode, but since instruction is restarted
+ * we have to do it here.
+ */
+ ctxt->decode.mem_read.end = 0;
+ return EMULATION_RESTART;
+ }
+ goto done; /* skip rip writeback */
}
}
- /*
- * reset read cache here in case string instruction is restared
- * without decoding
- */
- ctxt->decode.mem_read.end = 0;
- if (!ctxt->restart)
- ctxt->eip = c->eip;
+
+ ctxt->eip = c->eip;
done:
- return (rc == X86EMUL_UNHANDLEABLE) ? -1 : 0;
+ return (rc == X86EMUL_UNHANDLEABLE) ? EMULATION_FAILED : EMULATION_OK;
twobyte_insn:
switch (c->b) {