Re: [PATCH 2/3] conf, docs: Add support for dummy network interface

On Wed, Aug 24, 2022 at 04:09:31PM +0200, Martin Kletzander wrote: > On Tue, Aug 23, 2022 at 12:10:14PM +0100, Daniel P. Berrangé wrote: > > On Tue, Aug 23, 2022 at 01:01:49PM +0200, Martin Kletzander wrote: > > > On Tue, Aug 23, 2022 at 11:39:10AM +0100, Daniel P. Berrangé wrote: > > > > On Thu, Aug 04, 2022 at 03:07:17PM +0200, Martin Kletzander wrote: > > > > > Signed-off-by: Martin Kletzander <mkletzan(a)redhat.com&gt; > > > > > --- > > > > > docs/formatdomain.rst | 24 ++++++++++++++++++++++++ > > > > > src/ch/ch_monitor.c | 1 + > > > > > src/conf/domain_conf.c | 10 ++++++++++ > > > > > src/conf/domain_conf.h | 1 + > > > > > src/conf/netdev_bandwidth_conf.c | 1 + > > > > > src/conf/schemas/domaincommon.rng | 7 +++++++ > > > > > src/libxl/libxl_conf.c | 1 + > > > > > src/libxl/xen_common.c | 1 + > > > > > src/lxc/lxc_controller.c | 1 + > > > > > src/lxc/lxc_driver.c | 3 +++ > > > > > src/lxc/lxc_process.c | 4 +++- > > > > > src/qemu/qemu_command.c | 4 ++++ > > > > > src/qemu/qemu_domain.c | 1 + > > > > > src/qemu/qemu_hotplug.c | 3 +++ > > > > > src/qemu/qemu_interface.c | 2 ++ > > > > > src/qemu/qemu_process.c | 2 ++ > > > > > src/qemu/qemu_validate.c | 1 + > > > > > src/vmx/vmx.c | 1 + > > > > > tools/virsh-domain.c | 1 + > > > > > 19 files changed, 68 insertions(+), 1 deletion(-) > > > > > > > > > > diff --git a/docs/formatdomain.rst b/docs/formatdomain.rst > > > > > index adfdd7b7a5ac..ed0d9c19593b 100644 > > > > > --- a/docs/formatdomain.rst > > > > > +++ b/docs/formatdomain.rst > > > > > @@ -5240,6 +5240,30 @@ which the UDP socket packets will originate from the QEMU host. :since:`Since > > > > > </devices> > > > > > ... > > > > > > > > > > +Dummy network interface > > > > > +^^^^^^^^^^^^^^^^^^^^^^^ > > > > > + > > > > > +An unconnected network interface sounds pretty pointless, but can show up for > > > > > +example with VMWare when libvirt does not have any more information to provide. > > > > > +Two such scenarios are currently known: > > > > > + > > > > > +1) network interface exists, but is not connected to any existing network > > > > > +2) the interface is connected to something known as VMWare Distributed Switch > > > > > + > > > > > +The difference between these two is not (yet?) discoverable by libvirt, so at > > > > > +least the information gathered from the hypervisor is provided in the > > > > > +element. :since:`Since 8.7.0` > > > > > + > > > > > +:: > > > > > + > > > > > + ... > > > > > + <devices> > > > > > + <interface type='dummy'> > > > > > + <mac address='52:54:00:22:c9:42'/> > > > > > + </interface> > > > > > + </devices> > > > > > + ... > > > > > > > > Calling this 'dummy' is not very desirable naming. Especially since > > > > the distributed switch config is handled separately, we're just left > > > > with the case of a network interface without any host backend. > > > > > > > > > > I'll gladly rename this, I don't like dummy neither, but the only thing > > > I can think of is "unconnected". At first I went with existing type=direct, > > > but without <target dev=/>, only with <target managed='no'/>, but that > > > did not really make sense in my opinion. > > > > > > > IMHO this should just be type="none", and would likely be viable for > > > > QEMU too. > > > > > > > > > > Unfortunately type="none" usually (in our XML) means there is none of > > > this type of device (usb, memballoon, etc.), so I don't think that would > > > make sense compared to rest of our XML. > > > > Hmm, yes, good point. Some other ideas including yours.. > > > > type='unconnected' > > type='disconnected' > > type='unplugged' > > These seem to collide with <link state='down'/>, even though it really > is what VMWare seems to do on the NIC as well, just that you cannot > "plug" it anywhere. > > > type='null' (as in /dev/null alike) > > > > but together with this they are all better than "dummy", I agree. Any > preference before I send a rename patch? Perhaps a mild preference for the shorter names 'null' or 'unplugged'.

With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|