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

[Mark McLoughlin <markmc@redhat.com>]

On Fri, 2009-05-29 at 10:43 +0100, 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.

Okay, how about this:

  - Add a saveabi monitor command

  - Whenever libvirt starts a guest or hotplugs a device, it executes
    saveabi and retains the output

  - The abi can be restored with qemu -loadabi or the loadabi monitor 
    command

  - The abi file doesn't describe the device model, it merely gives 
    hints for building the device model which is described on the
    command line

  - If the abi file contains details of a device which is not listed on 
    the command line, it's just ignored and not included in the next 
    saveabi

  - If the abi file is missing details of a device which is listed on 
    the command line, the device is constructed using the defaults and 
    included in the next saveabi

  - This means the abi file is opaque to the management tools - unlike 
    the machine config file, libvirt would not need to modify it when
    devices are added or removed by the user

Cheers,
Mark.