From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754130AbaGHJZm (ORCPT ); Tue, 8 Jul 2014 05:25:42 -0400 Received: from mga01.intel.com ([192.55.52.88]:32673 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751842AbaGHJZi (ORCPT ); Tue, 8 Jul 2014 05:25:38 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,862,1389772800"; d="scan'208";a="360119301" Date: Tue, 8 Jul 2014 17:26:28 +0800 From: Wanpeng Li To: Paolo Bonzini Cc: Jan Kiszka , Bandan Das , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Gleb Natapov Subject: Re: [PATCH] KVM: x86: Check for nested events if there is an injectable interrupt Message-ID: <20140708092628.GA19860@kernel> Reply-To: Wanpeng Li References: <53BB86C2.9040805@redhat.com> <53BB9638.6040803@siemens.com> <53BBA523.4080006@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <53BBA523.4080006@redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 08, 2014 at 10:00:35AM +0200, Paolo Bonzini wrote: >Il 08/07/2014 08:56, Jan Kiszka ha scritto: >>I don't think arch.nmi_pending can flip asynchronously, only in the >>context of the VCPU thread - in contrast to pending IRQ states. > >Right, only nmi_queued is changed from other threads. /me should >really look at the code instead of going from memory. > >>>Jan, what do you think? Can you run Jailhouse through this patch? >> >>Jailhouse seems fine with it, and it resolves the lockup of nested KVM >>here as well. > >Thinking more about it, I think this is the right fix. Not setting >KVM_REQ_EVENT in some cases can be an optimization, but it's not >necessary. Definitely there are other cases in which KVM_REQ_EVENT >is set even though no event is pending---most notably during >emulation of invalid guest state. Anyway, Reviewed-by: Wanpeng Li > >Paolo