From 3e3d52c6346e3cd3b3ef5519dd2ea2082cee6a6a Mon Sep 17 00:00:00 2001 From: Nadav Amit Date: Sun, 2 Nov 2014 11:54:53 +0200 Subject: [PATCH] KVM: x86: Do not update EFLAGS on faulting emulation If the emulation ends in fault, eflags should not be updated. However, several instruction emulations (actually all the fastops) currently update eflags, if the fault was detected afterwards (e.g., #PF during writeback). Signed-off-by: Nadav Amit Signed-off-by: Paolo Bonzini --- arch/x86/kvm/x86.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 641358865a0c9..da1591eeb4773 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5360,7 +5360,9 @@ restart: kvm_rip_write(vcpu, ctxt->eip); if (r == EMULATE_DONE) kvm_vcpu_check_singlestep(vcpu, rflags, &r); - __kvm_set_rflags(vcpu, ctxt->eflags); + if (!ctxt->have_exception || + exception_type(ctxt->exception.vector) == EXCPT_TRAP) + __kvm_set_rflags(vcpu, ctxt->eflags); /* * For STI, interrupts are shadowed; so KVM_REQ_EVENT will -- 2.39.5