From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754309AbbIRQQl (ORCPT ); Fri, 18 Sep 2015 12:16:41 -0400 Received: from mx1.redhat.com ([209.132.183.28]:39610 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751527AbbIRQQg (ORCPT ); Fri, 18 Sep 2015 12:16:36 -0400 Date: Fri, 18 Sep 2015 18:16:32 +0200 From: Radim =?utf-8?B?S3LEjW3DocWZ?= To: "Wu, Feng" Cc: Paolo Bonzini , "alex.williamson@redhat.com" , "joro@8bytes.org" , "mtosatti@redhat.com" , "eric.auger@linaro.org" , "kvm@vger.kernel.org" , "iommu@lists.linux-foundation.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v8 03/13] KVM: Define a new interface kvm_intr_is_single_vcpu() Message-ID: <20150918161631.GA27908@potion.brq.redhat.com> References: <1442393409-2623-1-git-send-email-feng.wu@intel.com> <1442393409-2623-4-git-send-email-feng.wu@intel.com> <55F934F5.7040605@redhat.com> <55FA8AED.6090700@redhat.com> <55FACD35.1030602@redhat.com> <20150917155821.GB2573@potion.brq.redhat.com> <55FAE395.4000008@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2015-09-17 23:18+0000, Wu, Feng: >> From: Paolo Bonzini [mailto:pbonzini@redhat.com] >> On 17/09/2015 17:58, Radim Krčmář wrote: >>> xAPIC address are only 8 bit long so they always get delivered to x2APIC >>> cluster 0, where first 16 bits work like xAPIC flat logical mode. >> >> Ok, I was wondering whether this was the correct interpretation. Thanks! > > Paolo, I don't think Radim clarify your concern, right? Since mda is 8-bit, it > is wrong with mda >> 16, this is your concern, right? In case it was: mda is u32 so the bitshift is defined by C. (xAPIC destinations in KVM's x2APIC mode are stored in lowest 8 bits of mda, hence the cluster is always 0.) Or am I still missing the point?