Re: [Qemu-devel] [PATCH] add mac address collision checking for device_add & pci_add

[Lin Ma]

>>> Paolo Bonzini <address@hidden> 11/12/12 7:27 PM >>>
Il 12/11/2012 12:18, Daniel P. Berrange ha scritto:
>> > QEMU doesn't check if there are mac collisions when adding nics.
>> > It causes mac address collisions in guest if adding the nics which
>> > include existing physical address.
>> > This patch fixes the issue.
> I understand the issue, but are there not use cases where it is
> reasonable to have multiple NICs with the same MAC address ? To
> me this kind of policy enforcement belongs at a higher level in
> the mgmt stack.

>>>I agree.

Yes, Users won't intentionally add multiple NICs with the same MAC address.
But what if there is typos in command-line or upper layer applications pass a conflicting mac option to qemu?
We can't fully trust other applications to do this. So qemu shouldn't depend on other applications for the verifying mac.
No matter upper layer applications verify mac or not, qemu should check the mac itself again to ensure the correctness.

Lin