Re: [Qemu-devel] [PATCH 0/3] net: reimplement -net nic diagnostic fix

[Jan Kiszka <jan.kiszka@siemens.com>]

On 2011-05-20 18:04, Peter Maydell wrote:
> On 20 May 2011 16:55, Jan Kiszka <jan.kiszka@siemens.com> wrote:
>> On 2011-05-20 17:49, Peter Maydell wrote:
>>> This patchset reverts commit f68b9d672, which was triggering
>>> spuriously for NICs created via -device rather than -net nic.
>>> It then reimplements the improved diagnostics with a different
>>> approach which only applies to '-net nic'. (It's only -net nic
>>> devices that can be ignored (ie not instantiated); -device
>>> nic devices are always instantiated. Checking for -device user
>>> errors like "this device wasn't plugged into any bus" is
>>> a separate issue not addressed here.)
>>
>> But we still have the problem that qemu_new_nic does not call
>> net_init_nic. That means e.g. that NICs instantiated via -device don't
>> participate in automatic MAC assignment. Maybe fixing that makes this
>> series obsolete.
> 
> I think that avoiding MAC address clashes should be done by
> having net_init_nic() call qemu_macaddr_default_if_unset()

You mean qemu_new_nic? Otherwise it wouldn't help. Will have a look to
move that over.

> rather than doing its own MAC assignment.
> 
> Having qemu_new_nic() call net_init_nic() is a bit tricky
> because (a) as you said earlier you need to avoid doing
> it for NICs which were created from nd_table entries in the
> first place and (b) it imposes a new limit on the number
> of NICs you can create via -device which wasn't there before
> (because nd_table is fixed size).
> 
> I think I agree with Paul Brook's comment on IRC that the
> real long term solution is for nd_table[] to go away completely,
> (ie not for the new qdev option code to add entries in nd_table[]
> by calling net_init_nic().)

I don't disagree that nd_table is better removed. Then let's address all
those issues separately.

Jan

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