From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [PART1 RFC v2 07/10] svm: Add VMEXIT handlers for AVIC Date: Thu, 17 Mar 2016 10:35:05 +0100 Message-ID: <56EA7A49.4000004@redhat.com> 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> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit 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 To: Suravee Suthikulpanit , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= Return-path: In-Reply-To: <56EA2B4F.7050201@amd.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.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