From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [PATCH] KVM: VMX: fix halt emulation while emulating invalid guest sate Date: Wed, 8 May 2013 13:09:05 -0400 (EDT) Message-ID: <1123945336.8169090.1368032945270.JavaMail.root@redhat.com> References: <20130508153844.GG12349@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: kvm@vger.kernel.org, stable@vger.kernel.org To: Gleb Natapov Return-path: In-Reply-To: <20130508153844.GG12349@redhat.com> Sender: stable-owner@vger.kernel.org List-Id: kvm.vger.kernel.org ----- Messaggio originale ----- > Da: "Gleb Natapov" > A: kvm@vger.kernel.org > Cc: pbonzini@redhat.com, stable@vger.kernel.org > Inviato: Mercoled=C3=AC, 8 maggio 2013 17:38:44 > Oggetto: [PATCH] KVM: VMX: fix halt emulation while emulating invalid= guest sate >=20 > 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, s= o > 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. >=20 > 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 k= vm_vcpu > *vcpu) > return 0; > } > =20 > + if (vcpu->arch.halt_request) { > + vcpu->arch.halt_request =3D 0; > + ret =3D kvm_emulate_halt(vcpu); > + goto out; > + } > + > if (signal_pending(current)) > goto out; > if (need_resched()) > -- > Gleb. >=20 Reviewed-by: Paolo Bonzini