[libvirt] [PATCH] qemu: add macvlan delete to qemuDomainAttachNetDevice cleanup

[Viktor Mihajlovski]

On 07/02/2013 07:15 PM, Matthew Rosato wrote:
> On 07/01/2013 06:42 PM, Laine Stump wrote:
>> On 07/01/2013 11:04 AM, Viktor Mihajlovski wrote:
>>> From: Matthew Rosato <mjrosato at linux.vnet.ibm.com>
>>
>> This is a good catch, but incomplete. If you search for other
>> occurrences of virDomainConfNWFilterTeardown() and
>> qemuPhysIfaceConnect(), you will find the same problem exists in two
>> other places in the code:
>>
>>     qemuBuildInterfaceCommandLine (during error cleanup, needs to be
>> called
>>                                    for the one interface that was
>> partially
>>                                    created)
>>     qemuBuildCommandLine          (during error cleanup, needs to be
>> called
>>                                    for all interfaces that were
>> completely
>>                                    created (up to last_good_net))
>>
>> We really should fix them all in one patch, since they are all the same
>> problem.
>
> Thank you for your comments.  I tested the two cases that you mentioned
> by forcing errors; in both, the macvtap will be released by code in
> qemuProcessStop(), which releases any macvtap in the domain's nets list.
>   Is this sufficient, or did you still want something changed?
>
True ... the only other driver function that invokes qemBuildCommandLine
is connectDomainXMLToNative and here some premonition has prevented
the allocation of macvtap devices :)
>>
>> (Ideally, *all* guest interface setup for each interface should be
>> handled in a single function, and that function should be in the network
>> driver (networkReleaseActualDevice() seems properly situated). That way
>> it could be put behind an RPC, and the non-privileged libvirtd could
>> call it too (with proper credentials). That is a larger problem, though.)
>>
I agree, to both parts (proper structure and magnitude of effort).

Laine,
given that the patch solves the problem at hand and the other cases
are handled properly: are you OK with the current, simple approach?

The issue for us is that the dangling macvtap device prevents the reuse
of the interface's MAC address on s390 and there's no libvirt means
to delete the macvtap interface.

-- 

Mit freundlichen Grüßen/Kind Regards
    Viktor Mihajlovski

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