[Libvir] Proposal for virtual devices described in XML

Daniel P. Berrange berrange at redhat.com
Thu Sep 28 15:35:54 UTC 2006

On Thu, Sep 28, 2006 at 05:23:11PM +0200, michel.ponceau at bull.net wrote:
> When specified at device creation, vifname is put in XenStore directory 
> /local/domain/0/backend/vif/<domID>/<vif_number>. All vifnames used in a 
> domain are returned by Get "/xend/domain/<domID>?detail=1" and converted 
> into XML "target" by virDomainGetXMLDesc.

It seems XenD only writes the 'vifname' into xenstore if you explicitly
requested one. If you let XenD auto-allocate a vifname, it doesn't write
the name of the auto-allocated one into xenstore. Which really sucks :-(

> For convenience, we could force the vifname, either at domain creation or 
> in Attach, and ignore any "target" in "interface", except for Detach. The 
> vifname value could be the sequence number of network device creation in 
> domain (for Xen, it would be equal to vif number).

Except that it is not convenient for the person using the API, because
they have no easy well to determine what 'vifname' is used / free on the
host system. If we need a unique identifier to hook onto for purposes of
detaching devices then MAC address is only one we currently have available.
I'm afraid forcing use of vifname is just not going to work.

|=- Red Hat, Engineering, Emerging Technologies, Boston.  +1 978 392 2496 -=|
|=-           Perl modules: http://search.cpan.org/~danberr/              -=|
|=-               Projects: http://freshmeat.net/~danielpb/               -=|
|=-  GnuPG: 7D3B9505   F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505  -=| 

More information about the libvir-list mailing list