From d9271123a46011af26da680baeb7fdf67b498abf Mon Sep 17 00:00:00 2001 From: Gleb Natapov Date: Thu, 18 Mar 2010 15:20:22 +0200 Subject: [PATCH] KVM: x86 emulator: during rep emulation decrement ECX only if emulation succeeded Signed-off-by: Gleb Natapov Signed-off-by: Marcelo Tosatti --- arch/x86/kvm/emulate.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 3b32270a20db..594574d8b9e9 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -2411,13 +2411,13 @@ int emulator_task_switch(struct x86_emulate_ctxt *ctxt, } static void string_addr_inc(struct x86_emulate_ctxt *ctxt, unsigned long base, - int reg, unsigned long **ptr) + int reg, struct operand *op) { struct decode_cache *c = &ctxt->decode; int df = (ctxt->eflags & EFLG_DF) ? -1 : 1; - register_address_increment(c, &c->regs[reg], df * c->src.bytes); - *ptr = (unsigned long *)register_address(c, base, c->regs[reg]); + register_address_increment(c, &c->regs[reg], df * op->bytes); + op->ptr = (unsigned long *)register_address(c, base, c->regs[reg]); } int @@ -2483,7 +2483,6 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) goto done; } } - register_address_increment(c, &c->regs[VCPU_REGS_RCX], -1); c->eip = ctxt->eip; } @@ -2936,11 +2935,13 @@ writeback: if ((c->d & SrcMask) == SrcSI) string_addr_inc(ctxt, seg_override_base(ctxt, c), VCPU_REGS_RSI, - &c->src.ptr); + &c->src); if ((c->d & DstMask) == DstDI) - string_addr_inc(ctxt, es_base(ctxt), VCPU_REGS_RDI, - &c->dst.ptr); + string_addr_inc(ctxt, es_base(ctxt), VCPU_REGS_RDI, &c->dst); + + if (c->rep_prefix && (c->d & String)) + register_address_increment(c, &c->regs[VCPU_REGS_RCX], -1); /* Commit shadow register state. */ memcpy(ctxt->vcpu->arch.regs, c->regs, sizeof c->regs); -- 2.39.5