On 10/15/2013 08:36 PM, Eric Blake wrote:

On 10/14/2013 11:07 PM, Stefan Weil wrote:

Is it reasonable to get a random mac address in your guest? I don't
think so. It would no longer be possible to connect to a guest using
ssh, restart that guest and connect again with ssh.

Agreed - libvirt ALWAYS passes a MAC to qemu, even if the user did not
specify a MAC to libvirt, precisely because the MAC must be reproducible
rather than random to avoid changing the guest ABI.  I don't think this
patch is needed - it's up to management to use qemu correctly.

Yes, you are right in this condition. But qemu support Mac address unset.
Also we can get the ip address through a lot of different ways, like use
monitor to get the mac and then get the ip. So we can login use ssh.

But as you mentioned, this patch is not needed, I don't agree with you.

First, this patch just fix the Potential issue of this feature. Now libvirt
maybe can't triggered this issue, who can promise in future will not.

The second is, qemu not only be used by libvirt, lots of developers like
to use the command line to boot up the guest. And in the future, we
are not sure about other program will use qemu.

The third is, when one feature has a issue in qemu,
no matter when it is been triggered, should we not fix it?

Mike
Thanks