From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754091AbaLVEtM (ORCPT ); Sun, 21 Dec 2014 23:49:12 -0500 Received: from mga02.intel.com ([134.134.136.20]:8193 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753813AbaLVEtK convert rfc822-to-8bit (ORCPT ); Sun, 21 Dec 2014 23:49:10 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.04,691,1406617200"; d="scan'208";a="502440572" From: "Wu, Feng" To: Paolo Bonzini , "Zhang, Yang Z" , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , "x86@kernel.org" , Gleb Natapov , "dwmw2@infradead.org" , "joro@8bytes.org" , Alex Williamson , Jiang Liu CC: "iommu@lists.linux-foundation.org" , "linux-kernel@vger.kernel.org" , KVM list , Eric Auger , "Wu, Feng" Subject: RE: [v3 13/26] KVM: Define a new interface kvm_find_dest_vcpu() for VT-d PI Thread-Topic: [v3 13/26] KVM: Define a new interface kvm_find_dest_vcpu() for VT-d PI Thread-Index: AQHQHFdJKGnmBgjgtkW0V0luzfySRZybC0Fg Date: Mon, 22 Dec 2014 04:48:57 +0000 Message-ID: References: <1418397300-10870-1-git-send-email-feng.wu@intel.com> <1418397300-10870-14-git-send-email-feng.wu@intel.com> <549307A5.3060305@redhat.com> <5494131E.9030505@redhat.com> <549576C7.4030800@redhat.com> In-Reply-To: <549576C7.4030800@redhat.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > -----Original Message----- > From: Paolo Bonzini [mailto:paolo.bonzini@gmail.com] On Behalf Of Paolo > Bonzini > Sent: Saturday, December 20, 2014 9:17 PM > To: Wu, Feng; Paolo Bonzini; Zhang, Yang Z; Thomas Gleixner; Ingo Molnar; H. > Peter Anvin; x86@kernel.org; Gleb Natapov; dwmw2@infradead.org; > joro@8bytes.org; Alex Williamson; Jiang Liu > Cc: iommu@lists.linux-foundation.org; linux-kernel@vger.kernel.org; KVM list; > Eric Auger > Subject: Re: [v3 13/26] KVM: Define a new interface kvm_find_dest_vcpu() for > VT-d PI > > > > On 20/12/2014 00:48, Wu, Feng wrote: > > In my understanding, lowest priority interrupts are always delivered to a > > Single CPU, we need to find the right destination CPU from the cpumask. > > Yes, but which CPU however differs every time the interrupt is > delivered. So the emulation here is a bit poor. For now, please limit > PI to fixed interrupts. Do you mean we don't support Lowest priority interrupts? As I mentioned before, Lowest priority interrupts is widely used in Linux, so I think supporting lowest priority interrupts is very important for Linux guest OS. Do you have any ideas/suggestions about how to support Lowest priority interrupts for PI? Thanks a lot! Thanks, Feng > > > Actually, we don't support posting broadcast/multicast interrupts, because > > the interrupt is associated with one Posted-interrupts descriptor, then one > > vCPU. > > Understood. > > Paolo