Re: [Libvir] Inconsistent networking between Xen & QEMU
On Fri, Mar 09, 2007 at 07:17:04PM +0000, Mark McLoughlin wrote:
On Fri, 2007-03-09 at 18:52 +0000, Daniel P. Berrange wrote:
> On Fri, Mar 09, 2007 at 04:44:17PM +0000, Mark McLoughlin wrote:
> > Rather you suggest that if people want to use bridging, then they
> > should modify the default network XML config by hand and not have the
> > latter option in the UI?
>
> How they configure the network XML is a completely separate issue - we could
> easily have UI in virt-manager for creating/deleteing/editing networks in
> the same way we have UI for creating/deleting/editing domains.
... except you'd again have need an API for iterating physical network
devices ...
You say that like its a bad thing ? Virt-manager or other apps will need to
be able to enumerate physical devices somehow. So if libvirt is already
providing APIs for virtual networks a VM can connect to, why not also provide
APIs for physical devices (or figure out a way to let the existing virtual
networks API also deal with phys devices).
> > That introduces this user visible notion of a bridge vs. a router,
> > which is just horrible. But, I guess you're saying you wouldn't have
it
> > in the UI.
>
> Just because the different bridge vs routed confoigs are represented in the
> libvirt XML one way, doesn't force our hand in our we present it to the user.
> Any network with a '<device name='eth0'> tag could be displayed in
the
> 'physical interfaces' drop down, while any without that tag would be
> in the 'Network' drop down.
Well, except that you're suggesting "connect to physical interface
eth0" should be a property of a virtual network, but I think it makes
more sense for it to be the property of a virtual nic.
Well actually I'm suggesting 'connect to the physical network that eth0
is a part of' which doesn't feel much different to 'connect to the
virtual network'
NB, in all this discussion I'm talking about a scenario where the guest
can be connect to eth0 via a bridge. I've not even thought about a case
where you'd NAT a VIF directly into eth0 - that's probably irrelevant
use case now we have proper virtual networks - i only bring it up because
that is what xen's vif-route or vif-nat scripts do.
e.g. connect your qemu guests to the default network, connect your
Xen
guests to the eth0 bridge.
I'm just wondering whether this is making a distinction, where no real
distinction exists? If you run 'ifconfig' or 'brctl show' in either
of these two cases its going to look basically identical to the admin.
ie, there a bridge device, with one of more NICs in it, some virtual
NICs or TAPs, some physical NICs. If you run 'virsh net-list' you're
only going to see one of those cases
Regards,
Dan.
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