From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37190) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1f0l7t-0004Su-6a for qemu-devel@nongnu.org; Tue, 27 Mar 2018 05:42:46 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1f0l7q-0004OJ-54 for qemu-devel@nongnu.org; Tue, 27 Mar 2018 05:42:45 -0400 Received: from smtp02.citrix.com ([66.165.176.63]:36382) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1f0l7p-0004NB-V2 for qemu-devel@nongnu.org; Tue, 27 Mar 2018 05:42:42 -0400 Date: Tue, 27 Mar 2018 10:42:05 +0100 From: Anthony PERARD Message-ID: <20180327094204.GC2208@perard> References: <1520982894-4180-1-git-send-email-igor.druzhinin@citrix.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <1520982894-4180-1-git-send-email-igor.druzhinin@citrix.com> Subject: Re: [Qemu-devel] [PATCH v2] xen-pvdevice: Introduce a simplistic xen-pvdevice save state List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Igor Druzhinin Cc: qemu-devel@nongnu.org, xen-devel@lists.xenproject.org, sstabellini@kernel.org, paul.durrant@citrix.com, pbonzini@redhat.com, mst@redhat.com On Tue, Mar 13, 2018 at 11:14:54PM +0000, Igor Druzhinin wrote: > This should help to avoid problems with accessing the device after > migration/resume without PV drivers by migrating its PCI configuration > space state. Without an explicitly defined state record it resets > every time a VM migrates which confuses the OS and makes every > access to xen-pvdevice MMIO region to fail. PV tools enable some > logic to save and restore PCI configuration state from within the VM > every time it migrates which basically hides the issue. > > Older systems will acquire the new record when migrated which should > not change their state for worse. > > Signed-off-by: Igor Druzhinin > Reviewed-by: Paul Durrant > --- > v2: add more concrete info > --- > hw/i386/xen/xen_pvdevice.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) Acked-by: Anthony PERARD Thanks, -- Anthony PERARD