From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752438AbdJ3GUn (ORCPT ); Mon, 30 Oct 2017 02:20:43 -0400 Received: from mail-lf0-f46.google.com ([209.85.215.46]:47873 "EHLO mail-lf0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752129AbdJ3GUm (ORCPT ); Mon, 30 Oct 2017 02:20:42 -0400 X-Google-Smtp-Source: ABhQp+REB2A5+lMK/kDM50U+mSskJhbJctF/HBsJfd01H9Iy2Fw49bEj2qrlHVHP6A9qRmAx3CzgWQ== Date: Mon, 30 Oct 2017 07:20:32 +0100 From: Christoffer Dall To: Eric Auger Cc: eric.auger.pro@gmail.com, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu, marc.zyngier@arm.com, peter.maydell@linaro.org, andre.przywara@arm.com, wanghaibin.wang@huawei.com, wu.wubin@huawei.com, drjones@redhat.com, wei@redhat.com Subject: Re: [PATCH v6 0/9] vITS Migration fixes and reset Message-ID: <20171030062032.GL2166@lvm> References: <1509031391-4407-1-git-send-email-eric.auger@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1509031391-4407-1-git-send-email-eric.auger@redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Eric, On Thu, Oct 26, 2017 at 05:23:02PM +0200, Eric Auger wrote: > This series fixes various bugs observed when saving/restoring the > ITS state before the guest writes the ITS registers (on first boot or > after reset/reboot). > > This is a follow up of Wanghaibin's series [1] plus additional > patches following additional code review. It also proposes one > ITS reset implementation. > > Currently, the in-kernel emulated ITS is not reset. After a > reset/reboot, the ITS register values and caches are left > unchanged. Registers may point to some tables in guest memory > which do not exist anymore. If an ITS state backup is initiated > before the guest re-writes the registers, the save fails > because inconsistencies are detected. Also restore of data saved > as such moment is failing. > > Patches [1-4] are fixes of bugs observed during migration at > early guets boot stage. > - handle case where all collection, device and ITT entries are > invalid on restore (which is not an error) > - Check the GITS_BASER valid bit before attempting the save > any table > - Check the GITS_BASER and GITS_CBASER are valid before enabling > the ITS > > Patches [5-9] allow to empty the caches on reset and implement a > new ITS reset IOCTL I applied patches 1-4 to kvmarm/master and included them in a late pull request to kvm. I also took the remaining patches with the adjusted comment in kvmarm/next. One question: Don't we have a remaining issue to support saving the collection table even if the device table is inconsistent and vice versa? Are you planning on picking up that work? Thanks, -Christoffer