From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935351AbcCQJfO (ORCPT ); Thu, 17 Mar 2016 05:35:14 -0400 Received: from mail-wm0-f50.google.com ([74.125.82.50]:37651 "EHLO mail-wm0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932763AbcCQJfL (ORCPT ); Thu, 17 Mar 2016 05:35:11 -0400 Subject: Re: [PART1 RFC v2 07/10] svm: Add VMEXIT handlers for AVIC To: Suravee Suthikulpanit , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= References: <1457124368-2025-1-git-send-email-Suravee.Suthikulpanit@amd.com> <1457124368-2025-8-git-send-email-Suravee.Suthikulpanit@amd.com> <20160309205512.GD19459@potion.brq.redhat.com> <56EA2B4F.7050201@amd.com> Cc: joro@8bytes.org, bp@alien8.de, gleb@kernel.org, alex.williamson@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, wei@redhat.com, sherry.hurwitz@amd.com From: Paolo Bonzini Message-ID: <56EA7A49.4000004@redhat.com> Date: Thu, 17 Mar 2016 10:35:05 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <56EA2B4F.7050201@amd.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 17/03/2016 04:58, Suravee Suthikulpanit wrote: >>> >>> >+ BUG_ON(offset >= 0x400); >> These are valid faulting registers, so our implementation has to handle >> them. (And the rule is to never BUG if a recovery is simple.) >> > > Just want to clarify the part that you mentioned "to handle them". IIUC, > offet 0x400 and above are for x2APIC stuff, which AVIC does not > currently support. Also, since I have only advertised as xAPIC when > enabling AVIC, if we run into the situation that the VM is trying to > access these register, we should just ignore it (and not BUG). Do I > understand that correctly? Yes. You can add a printk(KERN_DEBUG) though. Paolo