On 11/13/2015 11:13 AM, Gerd Hoffmann wrote:
On Do, 2015-11-12 at 17:11 +0200, Marcel Apfelbaum wrote:
As part of porting the pxb device to Q35 remove the internal pci-2-pci
bridge. The only way to hot-pug devices on the extra PCI root buses
is by adding a pci-2-pci to the pxb before the firmware assign the
IO/mem resources.
I think this breaks live migration and is guest-visible too. So not
going to fly without backward-compatibility mode for old machine
types ...
Possibly it is easier to just have have pci and pcie pxb devices look
differenty rather than adding all the compatibility fluff.
Hi Gerd,
Thank you for the review.
Yes, you are right about migration, but I prefer to add a compat-prop rather
than different devices because I do want to remove the internal pci-bridge
even for pxb PCI.
The reason is the feedback I got from libvirt that "composed" device are not
recommended.
In conclusion, since I am going to get rid of the pci-bridge, the devices will
be exactly
the same (except for the internal bus).
I want to use the same concept as virtio-pci devices that get to be "express"
on PCIe,
but remain PCI on PCI buses.
Thanks,
Marcel
cheers,
Gerd
