[libvirt] [PATCH 4/4] qemu: support live change of all netdev hostside config

[Laine Stump]

On 10/13/2012 05:08 PM, Laine Stump wrote:
> On 10/12/2012 05:58 AM, Laine Stump wrote:
>> This is the final patch to resolve:
>>
>>   https://bugzilla.redhat.com/show_bug.cgi?id=805071
>>
>> This patch finalizes support live change of any/all hostside config of
>> a network device as part of the public virDomainUpdateDeviceFlags
>> API. The changes are done without detaching the device from the guest,
>> so hopefully disruptions are kept to a minimum.
>>
>> Two new functions are created for the task -
>> qemuDomainDetachNetHostSide() and qemuDomainAttachHostSide() - which
>> detach and reattach just the host side of a network device, while
>> leaving the PCI device on the guest side still attached. Calling these
>> two functions in sequence allows us to completely change the host side
>> of the device, including type of tap device, where the tap is
>> connected, bandwidth/vlan/virtualport settings, etc.
> Bah. This appears to not work properly. I sent mail to qemu-devel asking
> for clarification/help:
>
>   http://lists.nongnu.org/archive/html/qemu-devel/2012-10/msg02355.html
>
> So in the meantime I guess I need to pursue the "reattach the same tap
> device to a new bridge" idea as far as it will go, and save this patch
> for later :-(

I've just posted an "enhanced V2 of PATCH 3/4 which expands the
situations when a simple change of bridge attachment can satisfy the
update request. I'm now proposing a push of just PATCH 1/4 - 3/4, and
leaving 4/4 until the problem can be figured out.