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

[Michael S. Tsirkin]

On Wed, Dec 02, 2015 at 07:21:20PM +0200, Marcel Apfelbaum wrote:
> 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" <address@hidden> 
> >>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/address@hidden/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

Soon is not the right word. Closing in 10.. 9.. 8..