From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Wed, 8 May 2013 13:09:05 -0400 (EDT) From: Paolo Bonzini To: Gleb Natapov Cc: kvm@vger.kernel.org, stable@vger.kernel.org Message-ID: <1123945336.8169090.1368032945270.JavaMail.root@redhat.com> In-Reply-To: <20130508153844.GG12349@redhat.com> References: <20130508153844.GG12349@redhat.com> Subject: Re: [PATCH] KVM: VMX: fix halt emulation while emulating invalid guest sate MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT Sender: kvm-owner@vger.kernel.org List-ID: ----- Messaggio originale ----- > Da: "Gleb Natapov" > A: kvm@vger.kernel.org > Cc: pbonzini@redhat.com, stable@vger.kernel.org > Inviato: Mercoledì, 8 maggio 2013 17:38:44 > Oggetto: [PATCH] KVM: VMX: fix halt emulation while emulating invalid guest sate > > The invalid guest state emulation loop does not check halt_request > which causes 100% cpu loop while guest is in halt and in invalid > state, but more serious issue is that this leaves halt_request set, so > random instruction emulated by vm86 #GP exit can be interpreted > as halt which causes guest hang. Fix both problems by handling > halt_request in emulation loop. > > Reported-by: Tomas Papan > Tested-by: Tomas Papan > CC: stable@vger.kernel.org > Signed-off-by: Gleb Natapov > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index 5a87a58..a9fa4bc 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -5312,6 +5312,12 @@ static int handle_invalid_guest_state(struct kvm_vcpu > *vcpu) > return 0; > } > > + if (vcpu->arch.halt_request) { > + vcpu->arch.halt_request = 0; > + ret = kvm_emulate_halt(vcpu); > + goto out; > + } > + > if (signal_pending(current)) > goto out; > if (need_resched()) > -- > Gleb. > Reviewed-by: Paolo Bonzini