On Wed, Sep 04, 2013 at 10:35:34PM +0800, Osier Yang wrote: > On 04/09/13 03:13, Eric Blake wrote: > >On 09/03/2013 01:07 PM, Eric Blake wrote: > >>On 09/01/2013 07:43 AM, Nehal J Wani wrote: > >>>Define a new API virDomainInterfaceAddresses, which returns > >>>the address information of a running domain's interfaces(s). > >>>If no interface name is specified, it returns the information > >>>of all interfaces, otherwise it only returns the information > >>>of the specificed interface. The address information includes > >>>the MAC and IP addresses. > >>> > >>>Define helper function virDomainInterfaceFree, which allows > >>>the upper layer application to free the domain interface object > >>>conveniently. > >>> > >>>The API is going to provide multiple methods by flags, e.g. > >>> > >>> * Query guest agent > >>> * Parse lease file of dnsmasq > >>> * DHCP snooping > >>> > >>>But at this stage, it will only work with guest agent, and flags > >>>won't be supported. > >>That worries me a bit. Ultimately, we want our interfaces to behave as > >>sane as possible when flags==0; rather than making the behavior be that > >>'flags==0' implies 'only guest agent probe', I'd rather introduce a flag > >>right away up front that says 'include guest agent probe in the set of > >>attempted methods', and then document that 'flags==0 is shorthand for > >>letting the hypervisor choose the best method(s) out of supported > >>possibilities)'. In other words, I want to make sure that this API will > >>be similar to virDomainShutdownFlags, where a flags of 0 lets the > >>hypervisor choose between methods, a single explicit flag forces the > >>hypervisor to use that method alone, and more than one flag can be OR'd > >>together to let the hypervisor choose among that subset of flags. > >Hmm. I'm replying to myself - is that a good sign? > > > >If the guest agent returns names that are provided by the guest, and > >don't necessarily correspond to the domain XML, then maybe it's best to > >NEVER return guest results by default, but to make the user always > >explicitly request agent interaction. > > Hm, yes, the MAC address returned by guest agent might not > match what the domain config specifies. It reminds me something, > both the leases file and snooping will returns the interface name > like "vnetN", which is different with what guest agent returns (like > ethN or emN). And since the MAC address from guest agent might > be different with what domain config specifies, we have no way to > convert it into the names in domain config. That says we will have > different name styles for guest agent and the other two methods, > which will need quite documentations to explain. Such is life. We just have to document these naming limitations. Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :| -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list