From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751586AbcBLUF2 (ORCPT ); Fri, 12 Feb 2016 15:05:28 -0500 Received: from mail-wm0-f52.google.com ([74.125.82.52]:33264 "EHLO mail-wm0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750911AbcBLUF0 (ORCPT ); Fri, 12 Feb 2016 15:05:26 -0500 Subject: Re: [PART1 RFC 0/9] KVM: x86: Introduce SVM AVIC support To: Suravee Suthikulpanit , joro@8bytes.org, alex.williamson@redhat.com, gleb@kernel.org References: <1455285574-27892-1-git-send-email-suravee.suthikulpanit@amd.com> <56BE20CF.8030708@redhat.com> <56BE3897.5060507@amd.com> Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, wei@redhat.com, sherry.hurwitz@amd.com From: Paolo Bonzini Message-ID: <56BE3B02.20607@redhat.com> Date: Fri, 12 Feb 2016 21:05:22 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.5.0 MIME-Version: 1.0 In-Reply-To: <56BE3897.5060507@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 12/02/2016 20:55, Suravee Suthikulpanit wrote: >> Is it just this, or is there anything else? > > For VM Migration, I meant the process of taking a snapshot of the VM and > later on loading it back to resume where it left off, and not necessary > to a different type of system. This would require saving off the VAPIC > backing page of each vCPU along with the rest of per-VM AVIC data > structures. IIUC, this might require changes in the QEmu as well. It comes for free if you use regs for the backing page as I mentioned. QEMU then manipulates the registers as usual throgh KVM_GET_LAPIC/KVM_SET_LAPIC. Same for non-AVIC <-> AVIC migration. Paolo