Ping - since there wasn't any reply so far - any best practices one could share?
Let me add a TL;DR: - bump of ipxe rom versions change the size of virtio-net-pci.rom - that breaks on migration "Length mismatch" I'd guess the size of that rom has to be fixed up on the fly, but if that is really ok and how/where is the question. Also to +1 on bad things for today - I made this a cross post to libvirt in case there is one that has done that in the past. On Mon, Aug 28, 2017 at 4:36 PM, Christian Ehrhardt < christian.ehrha...@canonical.com> wrote: > Hi, > migration issues due to rom changes seem to occur over and over in past > years [1], [2],[3],[4],[5]. > From the past I know several workarounds (like just truncating to the > bigger size) but all have various deficiencies. > > But OTOH rom's will always change due to fixes in them. And recently I > found one such change [6] that affects the next Ubuntu release and wonder > what the ?right?, well lets say best way to fix it would be. > Current issue: > Length mismatch: 0000:00:03.0/virtio-net-pci.rom: 0x40000 in != 0x80000: > Invalid argument > Due to efi-virtio.rom growing over 256k due to an update to a newer ipxe > from upstream. > > I beg your pardon (for not being educated enough on this yet), but I want > to avoid to go a route that is fixing it in a sub-optimal way and ask for > some guidance. There might be better ways in the modern qemu of today than > there were in the past. > TL;DR I look for the best way (if any) to declare in the new qemu: "I know > that the old size was smaller, let me fix that up on migration". > > I'll try on my own as I expect the machine type structures/mechanisms (and > we have Ubuntu specific types that could encapsulate the rom status from > the ipxe package to be coupled with the type) have all that is needed. > Yet me almost randomly trying around there surely isn't the best way to go > - so if there is some existing case or a short hint at what in there might > be the best way to fixup a changed rom size on a migration I'd be very > happy to hear about that. > > [1]: https://bugs.launchpad.net/ubuntu/+source/qemu/+bug/1536331 > [2]: https://lists.gnu.org/archive/html/qemu-devel/2016-01/msg01881.html > [3]: https://bugzilla.redhat.com/show_bug.cgi?id=1293566 > [4]: https://bugzilla.redhat.com/show_bug.cgi?id=1090093 > [5]: https://forge.univention.org/bugzilla/show_bug.cgi?id=38877 > [6]: https://bugs.launchpad.net/ubuntu/+source/ipxe/+bug/1713490 > > P.S: As everybody else I don't mind so much on reverse migration to older > releases > > -- > Christian Ehrhardt > Software Engineer, Ubuntu Server > Canonical Ltd > -- Christian Ehrhardt Software Engineer, Ubuntu Server Canonical Ltd
