[libvirt] network ethernet - device not up and ip not assigned

Laine Stump laine at laine.org
Tue Aug 23 12:29:50 UTC 2016

On 08/23/2016 06:22 AM, Vasiliy Tolstov wrote:
> I'm install latest libvir and configure network to assign some ip to
> ethernet device.
> But after start tap device is down and no addresses assigned.
> My investigation:
> qemu_interface.c have functions:
> qemuInterfaceStartDevice and qemuInterfaceStopDevice
> In start device in case of ethernet device no action performed (this
> is bug i think).
> In stop device i see, that we try to assign ip address to device (why?)

ACCKKK!!! (and I mean that in the "Bill the Cat" manner, not the "Yes, I 
approve" manner)

That is obviously wrong, and the only reason for it that I can think of 
is some odd merge problem during one of the final rebases of the 
patches, since I tested it innumerable times prior to that.

> I think we need to move assigning addresses from stop device, to start
> device,

Yes, but I wonder if anything else got screwed up at the same time.

> also note, that for routes we need device to up (how we deal
> in case of user in xml specify device is down and have route element
> inside xml for this device?)

Interesting question. I guess the routes should be set whenever the 
device is ifup'ed, and maybe deleted when it's taken offline (if the tap 
itself isn't going to be deleted)

> In case of stop device i think we does not need anything (in case of
> linux) becaue when tap deleted routes and addresses dissapeared from
> the kernel.
> What do you think?

I think this would have been less likely to happen if I was actually 
*using* type='ethernet' myself :-)

If you want to send a patch to fix start/stop device I can look at it 
later today or tomorrow. After that I suppose it would e useful to go 
through a few tests and see what else is broken.

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