diff options
| author | Gleb Natapov <gleb@redhat.com> | 2010-08-25 12:47:43 +0300 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2010-10-24 10:51:34 +0200 |
| commit | d2ddd1c48364e4161052d6089f06b2cf3c50496b (patch) | |
| tree | f8dd6a949e5006e2f39575b567f22d9033b9d1a7 /arch/x86/kvm/emulate.c | |
| parent | 3e2f65d57a0c1897fcc3287eeb41f117f4d021e5 (diff) | |
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>
Diffstat (limited to 'arch/x86/kvm/emulate.c')
| -rw-r--r-- | arch/x86/kvm/emulate.c | 43 |
1 files changed, 19 insertions, 24 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 3dcbc1d0a59..ec35a71d8b5 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -437,7 +437,6 @@ static void emulate_exception(struct x86_emulate_ctxt *ctxt, int vec, 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 @@ x86_decode_insn(struct x86_emulate_ctxt *ctxt) 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 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) } 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 @@ writeback: 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) { |