From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932499AbcAYMWr (ORCPT ); Mon, 25 Jan 2016 07:22:47 -0500 Received: from mail-wm0-f67.google.com ([74.125.82.67]:34624 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756142AbcAYMWo (ORCPT ); Mon, 25 Jan 2016 07:22:44 -0500 Subject: Re: [PATCH v3 1/4] KVM: Recover IRTE to remapped mode if the interrupt is not single-destination To: =?UTF-8?Q?Radim_Krcm=c3=a1r?= , "Wu, Feng" References: <1453254177-103002-1-git-send-email-feng.wu@intel.com> <1453254177-103002-2-git-send-email-feng.wu@intel.com> <20160121161949.GA14104@potion.brq.redhat.com> <20160122130551.GA23362@potion.brq.redhat.com> Cc: "linux-kernel@vger.kernel.org" , "kvm@vger.kernel.org" From: Paolo Bonzini Message-ID: <56A6138E.9060805@redhat.com> Date: Mon, 25 Jan 2016 13:22:38 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.5.0 MIME-Version: 1.0 In-Reply-To: <20160122130551.GA23362@potion.brq.redhat.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 22/01/2016 14:05, Radim Krcmár wrote: > > This is a good question. I also thought about this before, but after > > thinking it a bit more, seems we don't need to do this. > > If we don't do this, the in-flight interrupts will continue to be > > delivered in PI mode while we are changing it to remapped > > mode in IRTE. Even if we do this, the in-flight interrupts are > > also delivered in PI mode before setting 'SN' anyway, so seems > > we really don't need this, what is your opinion? > I'd remove it. It may be necessary because IRTE writes (128 bits) are not atomic. If so, no need to send v5, I'll add it back. Paolo