On 02/08/2013 04:36 AM, Gerd Hoffmann wrote: > Hi, > >>> foo.img generated with stock qemu 1.3.1, migration fails with git >>> head, still >>> fails after reverting the seabios 1.7.2 update which supposedly >>> causes other >>> migrate issues (commit 3588185b8396eb97fd9efd41c2b97775465f67c4) >> >> So this is by design - that patch changes the rom size for revision 4 (which >> is the default for qemu 1.3.1) from 16384 bytes to 8192. This breaks >> migration from previously created revision 4 images... But it unbreaks >> migration from other revisions. Different things that could be done: do a >> special migration hook to copy from src 16384 byte rom bar to dst 8192 byte >> rom bar. Gerd, what do you think? > > So the change making the rpm 16k was before 1.3, the fix thereafter, and > now we have migration 1.2 -> 1.3 broken (maybe masked by -M 1.2 > defaulting to qxl rev 3), 1.3 -> 1.4 broken and 1.2 -> 1.4 working, correct? > > So a compat property changing the rom size to 16k for pc-1.3 should do > the trick I think. >
I took a stab at this, unfortunately the situation isn't that simple. qxl rom_size is actually dependent on the spice version we build against: stock qemu 1.2 built on F17 against spice-0.10.1: sizeof(QXLRom)=72 rom_size=8192 stock qemu 1.2 built on F18 against spice-0.12.2: sizeof(QXLRom)=1160 rom_size=16834 Maybe a more complex solution like Alon proposed up thread is needed. Thanks, Cole
