Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753978AbaLWArA (ORCPT ); Mon, 22 Dec 2014 19:47:00 -0500 Received: from mga03.intel.com ([134.134.136.65]:56668 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753421AbaLWAqv (ORCPT ); Mon, 22 Dec 2014 19:46:51 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.07,627,1413270000"; d="scan'208";a="641667695" From: "Zhang, Yang Z" To: Paolo Bonzini , "yong.y.wang@linux.intel.com" CC: "Wu, Feng" , "tglx@linutronix.de" , "mingo@kernel.org" , "hpa@linux.intel.com" , "x86@kernel.org" , "gleb@kernel.org" , "dwmw2@infradead.org" , "joro@8bytes.org" , "alex.williamson@redhat.com" , "jiang.liu-VuQAYsv1563Yd54FQh9/CA@public.gmane.org" , "iommu@lists.linux-foundation.org" , "linux-kernel@vger.kernel.org" , "kvm@vger.kernel.org" , "eric.auger@linaro.org" 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: AdAeSev6JAZ1DRo1S4ebIhUdqD2+fg== Date: Tue, 23 Dec 2014 00:46:44 +0000 Message-ID: References: <1415059685.1337085.1419266271242.JavaMail.zimbra@zmail13.collab.prod.int.phx2.redhat.com> In-Reply-To: <1415059685.1337085.1419266271242.JavaMail.zimbra@zmail13.collab.prod.int.phx2.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 sBN0lH50000505 Paolo Bonzini wrote on 2014-12-23: >> The problem is we still need to support PI with lowest priority >> delivery mode > even if guest does not configure irq affinity via /proc/irq/. Don't we? > > Yes, but we can get the basic support working first. > > I and Feng talked on irc and agreed to start with a simple > implementation. Then he can add support for vector hashing for all > interrupts, both vt-d pi and normal LAPIC interrupts. Agree. Obviously, current PI has some limitations to achieve highest performance. We can start with a simple implementation but must ensure we don't change hardware's behavior(From guest's point). Feng's current implementation or use the way I suggested are both ok since both of them cannot solve the problem well. > > Paolo > Best regards, Yang ????{.n?+???????+%?????ݶ??w??{.n?+????{??G?????{ay?ʇڙ?,j??f???h?????????z_??(?階?ݢj"???m??????G????????????&???~???iO???z??v?^?m???? ????????I?