Re: [Qemu-devel] [PATCH 0/2] fix macaddr allocation

[Stefan Hajnoczi]

On Mon, Jun 17, 2013 at 09:35:09PM +0800, Amos Kong wrote:
> This patchset adds a check in allocating mac to new nic,
> it will avoid to use repeated mac. The second extends
> the address space.
> 
> Amos Kong (2):
>   avoid to allcate used macaddr to to new nic
>   extend the macaddr space to 0xffffffff
> 
>  net/net.c | 38 ++++++++++++++++++++++++++++++++++----
>  1 file changed, 34 insertions(+), 4 deletions(-)

I agree with Michael here and think neither patch should be merged.

Both of these patches provide some level of convenience but they cannot
solve the problem.  Things already work fine automatically in small
setups where the user depends on QEMU to handle MAC allocation.

In bigger setups you absolutely have to manage MACs or face collisions.
So I don't think it's worth trying to maintain the illusion in
scenarios that are too complex to automatically allocate for.

Stefan