diff options
| -rw-r--r-- | arch/x86/kvm/emulate.c | 41 |
1 files changed, 20 insertions, 21 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 09c9210..aab62d5 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -2781,28 +2781,10 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) ctxt->restart = true; /* All REP prefixes have the same first termination condition */ if (address_mask(c, c->regs[VCPU_REGS_RCX]) == 0) { - string_done: ctxt->restart = false; ctxt->eip = c->eip; goto done; } - /* The second termination condition only applies for REPE - * and REPNE. Test if the repeat string operation prefix is - * REPE/REPZ or REPNE/REPNZ and if it's the case it tests the - * corresponding termination condition according to: - * - if REPE/REPZ and ZF = 0 then done - * - if REPNE/REPNZ and ZF = 1 then done - */ - if ((c->b == 0xa6) || (c->b == 0xa7) || - (c->b == 0xae) || (c->b == 0xaf)) { - if ((c->rep_prefix == REPE_PREFIX) && - ((ctxt->eflags & EFLG_ZF) == 0)) - goto string_done; - if ((c->rep_prefix == REPNE_PREFIX) && - ((ctxt->eflags & EFLG_ZF) == EFLG_ZF)) - goto string_done; - } - c->eip = ctxt->eip; } if ((c->src.type == OP_MEM) && !(c->d & NoAccess)) { @@ -3229,20 +3211,37 @@ writeback: if (c->rep_prefix && (c->d & String)) { struct read_cache *rc = &ctxt->decode.io_read; register_address_increment(c, &c->regs[VCPU_REGS_RCX], -1); + /* The second termination condition only applies for REPE + * and REPNE. Test if the repeat string operation prefix is + * REPE/REPZ or REPNE/REPNZ and if it's the case it tests the + * corresponding termination condition according to: + * - if REPE/REPZ and ZF = 0 then done + * - if REPNE/REPNZ and ZF = 1 then done + */ + if (((c->b == 0xa6) || (c->b == 0xa7) || + (c->b == 0xae) || (c->b == 0xaf)) + && (((c->rep_prefix == REPE_PREFIX) && + ((ctxt->eflags & EFLG_ZF) == 0)) + || ((c->rep_prefix == REPNE_PREFIX) && + ((ctxt->eflags & EFLG_ZF) == EFLG_ZF)))) + ctxt->restart = false; /* * Re-enter guest when pio read ahead buffer is empty or, * if it is not used, after each 1024 iteration. */ - if ((rc->end == 0 && !(c->regs[VCPU_REGS_RCX] & 0x3ff)) || - (rc->end != 0 && rc->end == rc->pos)) + else if ((rc->end == 0 && !(c->regs[VCPU_REGS_RCX] & 0x3ff)) || + (rc->end != 0 && rc->end == rc->pos)) { ctxt->restart = false; + c->eip = ctxt->eip; + } } /* * reset read cache here in case string instruction is restared * without decoding */ ctxt->decode.mem_read.end = 0; - ctxt->eip = c->eip; + if (!ctxt->restart) + ctxt->eip = c->eip; done: return (rc == X86EMUL_UNHANDLEABLE) ? -1 : 0; |