Re: Q: How to find own domid or uuid from domU?

[Markus Armbruster <armbru@redhat.com>]

Keir Fraser <Keir.Fraser@cl.cam.ac.uk> writes:

> On 18 May 2006, at 10:46, Markus Armbruster wrote:
>
>> I can map from domid to uuid by reading /local/domain/DOMID/vm.
>>
>> I got that to work by trying DOMIDs starting with 0 until the read
>> succeeds, but that's kind of gross.
>>
>> I can think of some less gross methods to find my domid, but I'd still
>> be glad to hear suggestions.
>
> Don't use DOMID. It can change across save/restore and migration.

No plans to expose it to anything.  I got interested in it just as a
means to obtain the UUID.

>> Would you like to have an interface for obtaining one's UUID?  What
>> about adding a XENVER_get_uuid code to HYPERVISOR_xen_version()?
>
> That might be okay, although even that might appear to change if we
> implement things like VM fork in future.

No problem as long as the information remains available somewhere.

> Why does your guest need to know its ID?

So that managament tools have a way of associating a running domain
with persistent state such as config files, regardless of where on a
network the domain is running at any time.