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.
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
