Re: Configuration vs. compat hints [was Re: [Qemu-devel] [PATCHv3 03/13] qemu: add routines to manage PCI capabilities]

Avi Kivity
2009-06-17T06:40:42Z

On 06/16/2009 09:32 PM, Jamie Lokier wrote:
> Avi Kivity wrote:
>
>> Another issue is enumeration. Guests will present their devices in the
>> order they find them on the pci bus (of course enumeration is guest
>> specific). So if I have 2 virtio controllers the only way I can
>> distinguish between them is using their pci slots.
>>
>
> virtio controllers really should have a user-suppliable string or UUID
> to identify them to the guest. Don't they?
>

virtio controllers don't exist. When they do, they may have a UUID or
not, but in either case guest infrastructure is in place for reporting
the PCI slot, not the UUID.

virtio disks do have a UUID. I don't think older versions of Windows
will use it though, so if you reorder your slots you'll see your drive
letters change. Same with Linux if you don't use udev by-uuid rules.

--
Do not meddle in the internals of kernels, for they are subtle and quick to panic.