Re: [Qemu-devel] [PATCH v2 for-2.5] virtio-pci: Set the QEMU_PCI_CAP_EXPRESS capability early in its DeviceClass realize method

[Marcel Apfelbaum <marcel@redhat.com>]

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" <mst@redhat.com> 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