From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49651) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aHWE4-00029q-Du for qemu-devel@nongnu.org; Fri, 08 Jan 2016 07:33:05 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aHWE0-0001BG-Cx for qemu-devel@nongnu.org; Fri, 08 Jan 2016 07:33:04 -0500 Received: from mx1.redhat.com ([209.132.183.28]:34682) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aHWE0-0001BC-8N for qemu-devel@nongnu.org; Fri, 08 Jan 2016 07:33:00 -0500 Message-ID: <1452256376.21093.50.camel@redhat.com> From: Gerd Hoffmann Date: Fri, 08 Jan 2016 13:32:56 +0100 In-Reply-To: References: <1451994098-6972-1-git-send-email-kraxel@redhat.com> <1451994098-6972-12-git-send-email-kraxel@redhat.com> <1452152339.6096.78.camel@redhat.com> <1452181822.6096.140.camel@redhat.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH v3 11/11] igd: move igd-passthrough-isa-bridge creation to machine init List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefano Stabellini Cc: igvt-g@ml01.01.org, xen-devel@lists.xensource.com, Eduardo Habkost , "Michael S. Tsirkin" , Andrew Cooper , xudong.hao@intel.com, qemu-devel@nongnu.org, Jan Beulich , Cao jin , vfio-users@redhat.com, Paolo Bonzini , Richard Henderson Hi, > > That is true. Given that the only qemu-xen codebase with igd support is > > 4.7 and 4.7 hasn't been released yet, I am OK with changing the guest > > visible PCI layout. I might ask for your help in backporting the patche= s > > ;-) What are the 4.7 release plans btw? > One thing that I forgot to consider is that QEMU 2.5 has been released > with igd passthrough too and Xen 4.6 + QEMU 2.5 is a combination we > should support. >=20 > However QEMU 2.5 has a serious bug > (http://marc.info/?l=3Dqemu-devel&m=3D145172165010604) which probably > prevents igd passthrough from working at all. Stumbled over that one too, so my series has a (different) fix for it as well. > I asked Xudong to investigate. I am thinking that if the feature > works in 2.5, we need to support it, therefore we cannot break > migration by changing the PCI layout. I'd expect it is broken (at least for older guests). In case 2.5 works fine as-is we should be able to ditch TYPE_IGD_PASSTHROUGH_I440FX_PCI_DEVICE altogether b/c it is a no-op in 2.5 because of the bug. But lets wait for the test results ... > Otherwise if the feature doesn't work, we could take the liberty to > make the change. Do you agree? Yes. cheers, Gerd From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gerd Hoffmann Subject: Re: [PATCH v3 11/11] igd: move igd-passthrough-isa-bridge creation to machine init Date: Fri, 08 Jan 2016 13:32:56 +0100 Message-ID: <1452256376.21093.50.camel@redhat.com> References: <1451994098-6972-1-git-send-email-kraxel@redhat.com> <1451994098-6972-12-git-send-email-kraxel@redhat.com> <1452152339.6096.78.camel@redhat.com> <1452181822.6096.140.camel@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org Sender: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org To: Stefano Stabellini Cc: igvt-g@ml01.01.org, xen-devel@lists.xensource.com, Eduardo Habkost , "Michael S. Tsirkin" , Andrew Cooper , xudong.hao@intel.com, qemu-devel@nongnu.org, Jan Beulich , Cao jin , vfio-users@redhat.com, Paolo Bonzini , Richard Henderson List-Id: xen-devel@lists.xenproject.org Hi, > > That is true. Given that the only qemu-xen codebase with igd support is > > 4.7 and 4.7 hasn't been released yet, I am OK with changing the guest > > visible PCI layout. I might ask for your help in backporting the patche= s > > ;-) What are the 4.7 release plans btw? > One thing that I forgot to consider is that QEMU 2.5 has been released > with igd passthrough too and Xen 4.6 + QEMU 2.5 is a combination we > should support. >=20 > However QEMU 2.5 has a serious bug > (http://marc.info/?l=3Dqemu-devel&m=3D145172165010604) which probably > prevents igd passthrough from working at all. Stumbled over that one too, so my series has a (different) fix for it as well. > I asked Xudong to investigate. I am thinking that if the feature > works in 2.5, we need to support it, therefore we cannot break > migration by changing the PCI layout. I'd expect it is broken (at least for older guests). In case 2.5 works fine as-is we should be able to ditch TYPE_IGD_PASSTHROUGH_I440FX_PCI_DEVICE altogether b/c it is a no-op in 2.5 because of the bug. But lets wait for the test results ... > Otherwise if the feature doesn't work, we could take the liberty to > make the change. Do you agree? Yes. cheers, Gerd