On Tue, Apr 25, 2023 at 12:02:49AM +0300, Vladimir Sementsov-Ogievskiy wrote: > On 24.04.23 23:45, Michael S. Tsirkin wrote: > > On Mon, Apr 24, 2023 at 04:42:00PM -0400, Michael S. Tsirkin wrote: > > > On Mon, Apr 24, 2023 at 11:36:47PM +0300, Vladimir Sementsov-Ogievskiy > > > wrote: > > > > On migration, on target we load local ROM file. But actual ROM content > > > > migrates through migration channel. Original ROM content from local > > > > file doesn't matter. But when size mismatch - we have an error like > > > > > > > > Size mismatch: 0000:00:03.0/virtio-net-pci.rom: 0x40000 != 0x80000: > > > > Invalid argument > > > > > > > > Let's just allow resizing of ROM memory. This way migration is not > > > > relate on local ROM file on target node which is loaded by default but > > > > is not actually needed. > > > > > > > > Signed-off-by: Vladimir Sementsov-Ogievskiy<vsement...@yandex-team.ru> > > Also isn't ROM size reflected in config space etc? > > I don't remember code that would update that on migration. > > > > > > Thanks a lot for fast answers! > > Hmm. I'm a newbie in these things. > > But yes, I noted, that my patch helps, if, for example jump from 200K to 500K > zero-filled ROM file. But if jump to 600K, migration fails with > > (qemu) qemu: get_pci_config_device: Bad config data: i=0x32 read: b8 device: > 0 cmask: ff wmask: f0 w1cmask:0 > qemu: Failed to load PCIDevice:config > qemu: Failed to load virtio-net:virtio > qemu: error while loading state for instance 0x0 of device > '0000:00:03.0/virtio-net' > qemu: load of migration failed: Invalid argument > > > I thought, that, maybe, romfile for this device just mustn't be more than > 512K where config starts. But now I think that it's exactly the problem you > are saying about. > > > I know also, that there were another step around this problem: > 08b1df8ff463e72b087 "pci: add romsize property".. But it doesn't help when > you already have a running instance with small ROM and want to migrate it to > the node where you have corresponding local ROM file updated to new package > with bigger size. >
set romsize on destination? > Hmm. So, simply reuse "resizable" memory blocks doesn't help. And I need more > precise reinitialization of device on load of incoming migration.. > > -- > Best regards, > Vladimir
