Re: [Qemu-devel] [PATCH] Change virtio-console to PCI_CLASS_SERIAL_OTHER

[Anthony Liguori <aliguori@us.ibm.com>]

Mark McLoughlin wrote:
> The more I think about it, no matter how much linear ABI versioning
> sucks, it's possibly the only way to solve this in a reasonably usable
> manners. Distros would just have to suck it up and agree that if they
> cherry-pick an ABI changing patch, they must update the entire ABI to
> the newer upstream ABI version.
>   

If we modify pci_qdev_register() to take the savevm functions and pass
the qdev to each handler as a convention, we could then leverage the
version id of the device to implement the device versioning logic.  We
would also be able to query what the current versions are in the monitor.

Moreover, we could walk the device tree before savevm to validate that
every device in the tree supports savevm which means we can fail
gracefully in when the chosen device model doesn't support live migration.

It's a large refactoring, but mostly mechanical.  Any takers?

Regards,

Anthony Liguori

> Cheers,
> Mark.
>
>