From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33334) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a4B5r-00067R-3B for qemu-devel@nongnu.org; Wed, 02 Dec 2015 12:21:28 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1a4B5n-0002Ez-Kh for qemu-devel@nongnu.org; Wed, 02 Dec 2015 12:21:27 -0500 Received: from mx1.redhat.com ([209.132.183.28]:46625) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a4B5n-0002Eu-Fk for qemu-devel@nongnu.org; Wed, 02 Dec 2015 12:21:23 -0500 References: <1449066801-3002-1-git-send-email-shmulik.ladkani@ravellosystems.com> <565F0A20.8050507@redhat.com> <20151202184610-mutt-send-email-mst@redhat.com> <20151202191247.7326c7a3@halley> <20151202191841-mutt-send-email-mst@redhat.com> From: Marcel Apfelbaum Message-ID: <565F2890.5080801@redhat.com> Date: Wed, 2 Dec 2015 19:21:20 +0200 MIME-Version: 1.0 In-Reply-To: <20151202191841-mutt-send-email-mst@redhat.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v2 for-2.5] virtio-pci: Set the QEMU_PCI_CAP_EXPRESS capability early in its DeviceClass realize method List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" , Shmulik Ladkani Cc: qemu-devel@nongnu.org On 12/02/2015 07:19 PM, Michael S. Tsirkin wrote: > On Wed, Dec 02, 2015 at 07:12:47PM +0200, Shmulik Ladkani wrote: >> Hi Michael, >> >> On Wed, 2 Dec 2015 18:49:24 +0200 "Michael S. Tsirkin" wrote: >>> On Wed, Dec 02, 2015 at 05:11:28PM +0200, Marcel Apfelbaum wrote: >>>> The only thing I want to mention here, (see earlier discussion: https://www.mail-archive.com/qemu-devel@nongnu.org/msg338963.html) >>>> is that in some cases the PCI config space will have PCIe length, even if the device is not express. >>>> >>>> To be more precise, the only interesting scenario is when we plug a virtio device directly into >>>> the root complex, in this case we'll have a PCI device with a PCIe config space. >>>> >>>> However this happens for other devices as well, it looks like a common practice. >>> >>> Problem is, if this happens migration breaks as we >>> changed config space size from 2.4. >> >> Correct me if wrong, but as long as a pre 2.5 hardware is used, Marcel's >> x-disable-pcie gets on (see HW_COMPAT_2_4), thus the device will not be >> a "pci_is_express", and it will have a small config space size. Isn't it >> so? >> >> Regards, >> Shmulik > > OK. Still, I do not want to migrate 4k of config space > for pci devices. > Shmulik, will you resend the patch with this minor change, or you prefer me to do it? 2.5 closes soon. Thanks, Marcel