From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933306Ab3E1Dzs (ORCPT ); Mon, 27 May 2013 23:55:48 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:52479 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758733Ab3E1DyN (ORCPT ); Mon, 27 May 2013 23:54:13 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Gleb Natapov" , "Paolo Bonzini" , "Tomas Papan" Date: Tue, 28 May 2013 04:49:53 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [23/94] KVM: VMX: fix halt emulation while emulating invalid guest sate In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.101 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.46-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Gleb Natapov commit 8d76c49e9ffeee839bc0b7a3278a23f99101263e upstream. 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 Reviewed-by: Paolo Bonzini Signed-off-by: Gleb Natapov Signed-off-by: Ben Hutchings --- arch/x86/kvm/vmx.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -4882,6 +4882,12 @@ static int handle_invalid_guest_state(st if (err != EMULATE_DONE) 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())