From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754444AbbATVEW (ORCPT ); Tue, 20 Jan 2015 16:04:22 -0500 Received: from mail-wg0-f42.google.com ([74.125.82.42]:55753 "EHLO mail-wg0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753471AbbATVET convert rfc822-to-8bit (ORCPT ); Tue, 20 Jan 2015 16:04:19 -0500 Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 8.1 \(1993\)) Subject: Re: [v3 13/26] KVM: Define a new interface kvm_find_dest_vcpu() for VT-d PI From: Nadav Amit In-Reply-To: <20150114165909.GA1283@potion.brq.redhat.com> Date: Tue, 20 Jan 2015 23:04:14 +0200 Cc: "Wu, Feng" , "kvm@vger.kernel.org" , "eric.auger@linaro.org" , "gleb@kernel.org" , "x86@kernel.org" , "linux-kernel@vger.kernel.org" , "iommu@lists.linux-foundation.org" , "mingo@redhat.com" , "hpa@zytor.com" , Paolo Bonzini , "tglx@linutronix.de" , "dwmw2@infradead.org" , "jiang.liu@linux.intel.com" Content-Transfer-Encoding: 8BIT Message-Id: <6A3B67DA-EDAA-4DE5-BE59-96B693D7BB86@gmail.com> References: <1418397300-10870-1-git-send-email-feng.wu@intel.com> <1418397300-10870-14-git-send-email-feng.wu@intel.com> <20150109145435.GA22469@potion.brq.redhat.com> <54AFEC00.80507@redhat.com> <20150113161716.GA12941@potion.brq.redhat.com> <20150114165909.GA1283@potion.brq.redhat.com> To: =?utf-8?Q?Radim_Kr=3Fm=C3=A1=3F?= X-Mailer: Apple Mail (2.1993) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Radim Kr?má? wrote: > 2015-01-14 01:27+0000, Wu, Feng: >>> the new >>>> hardware even doesn't consider the TPR for lowest priority interrupts >>> delivery. >>> >>> A bold move ... what hardware was the first to do so? >> >> I think it was starting with Nehalem. > > Thanks, (Could be that QPI can't inform about TPR changes anymore ...) > > I played with Linux's TPR on Haswell and found that is has no effect. Sorry for jumping into the discussion, but doesn’t it depend on IA32_MISC_ENABLE[23]? This bit disables xTPR messages. On my machine it is set (probably by the BIOS), but since there is no IA32_MISC_ENABLE is not locked for changes, the OS can control it. Nadav