From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gleb Natapov Subject: [PATCH] KVM: VMX: fix halt emulation while emulating invalid guest sate Date: Wed, 8 May 2013 18:38:44 +0300 Message-ID: <20130508153844.GG12349@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: pbonzini@redhat.com, stable@vger.kernel.org To: kvm@vger.kernel.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:37954 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754227Ab3EHPis (ORCPT ); Wed, 8 May 2013 11:38:48 -0400 Content-Disposition: inline Sender: kvm-owner@vger.kernel.org List-ID: 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.