EFLAGS.ZF needs to be checked after each iteration, not before. Signed-off-by: Avi Kivity <a...@redhat.com> --- arch/x86/kvm/emulate.c | 42 +++++++++++++++++++++++------------------- 1 files changed, 23 insertions(+), 19 deletions(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 0c0ada9..a2edfb1 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -2747,6 +2747,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) int rc = X86EMUL_CONTINUE; int saved_dst_type = c->dst.type; int irq; /* Used for int 3, int, and into */ + ulong old_eip; ctxt->decode.mem_read.pos = 0; @@ -2771,28 +2772,10 @@ 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) { @@ -3229,6 +3212,7 @@ special_insn: } writeback: + old_eip = c->eip; rc = writeback(ctxt, ops); if (rc != X86EMUL_CONTINUE) goto done; @@ -3250,13 +3234,33 @@ 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)) { + trace_printk("c->eip %lx ctxt->eip %lx\n", + c->eip, ctxt->eip); + if (((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)) + (rc->end != 0 && rc->end == rc->pos)) { ctxt->restart = false; + c->eip = ctxt->eip; + } } /* * reset read cache here in case string instruction is restared -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html