Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752377AbaKLJXc (ORCPT ); Wed, 12 Nov 2014 04:23:32 -0500 Received: from mga14.intel.com ([192.55.52.115]:54780 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752121AbaKLJX3 (ORCPT ); Wed, 12 Nov 2014 04:23:29 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,862,1389772800"; d="scan'208";a="415286518" From: "Wu, Feng" To: Paolo Bonzini , "Zhang, Yang Z" , Alex Williamson CC: "gleb@kernel.org" , "dwmw2@infradead.org" , "joro@8bytes.org" , "tglx@linutronix.de" , "mingo@redhat.com" , "hpa@zytor.com" , "x86@kernel.org" , "kvm@vger.kernel.org" , "iommu@lists.linux-foundation.org" , "linux-kernel@vger.kernel.org" Subject: RE: [PATCH 05/13] KVM: Update IRTE according to guest interrupt configuration changes Thread-Topic: [PATCH 05/13] KVM: Update IRTE according to guest interrupt configuration changes Thread-Index: Ac/9kLfHSOSyagtOQAqEsc5J81STLgAyIb0DAAAcBYA= Date: Wed, 12 Nov 2014 09:19:55 +0000 Message-ID: References: <5461EC99.1000101@redhat.com> <546324F4.8010002@redhat.com> In-Reply-To: <546324F4.8010002@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="utf-8" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by nfs id sAC9NePs016018 > -----Original Message----- > From: Paolo Bonzini [mailto:pbonzini@redhat.com] > Sent: Wednesday, November 12, 2014 5:14 PM > To: Zhang, Yang Z; Wu, Feng; Alex Williamson > Cc: gleb@kernel.org; dwmw2@infradead.org; joro@8bytes.org; > tglx@linutronix.de; mingo@redhat.com; hpa@zytor.com; x86@kernel.org; > kvm@vger.kernel.org; iommu@lists.linux-foundation.org; > linux-kernel@vger.kernel.org > Subject: Re: [PATCH 05/13] KVM: Update IRTE according to guest interrupt > configuration changes > > > > On 12/11/2014 04:42, Zhang, Yang Z wrote: > > Personally, I think this feature will be helpful to the legacy device > > assignment. Agree, vfio is the right solution for future feature > > enabling. But the old kvm without the good vfio supporting is still > > used largely today. The user really looking for this feature but they > > will not upgrade their kernel. It's easy for us to backport this > > feature to old kvm with the legacy device assignment, but it is > > impossible to backport the whole vfio. > > You can certainly backport these patches to distros that do not have > VFIO. But upstream we should work on VFIO first. VFIO has feature > parity with legacy device assignment, and adding a new feature that is > not in VFIO would be a bad idea. > > By the way, do you have benchmark results for it? We have not been able > to see any performance improvement for APICv on e.g. netperf. Do you mean benchmark results for APICv itself or VT-d Posted-Interrtups? Thanks, Feng > > Paolo ????{.n?+???????+%?????ݶ??w??{.n?+????{??G?????{ay?ʇڙ?,j??f???h?????????z_??(?階?ݢj"???m??????G????????????&???~???iO???z??v?^?m???? ????????I?