Re: [Qemu-devel] [PATCH v3 2/2] net: introduce command to query rx-filter information

[Markus Armbruster]

Amos Kong <address@hidden> writes:

> On Tue, Jul 02, 2013 at 11:05:56AM +0200, Markus Armbruster wrote:
>> Amos Kong <address@hidden> writes:
[...]
>> >> This interface is abstract in the sense that it applies to all NICs.  At
>> >> this time, it's implemented only virtio-net implements it.  I'm
>> >> habitually wary of abstractions based on just one concrete instance,
>> >> which makes me ask:
>> >> 
>> >> 1. Ignorant question first: could the feature make sense for other NICs,
>> >> too, or is it specific to virtio-net?
>> >
>> > We will not. 
>> >
>> > It's ugly to check if nic is virtio-net nic in net/net.c, so I
>> > register the query function to NetClientInfo. Traversal the net
>> > client list in net/net.c, and execute query of each virtio-net
>> > instance in virtio-net.c
>> 
>> Implementing the feature as an optional callback is fine.
>> 
>> Let me rephrase my question: could this feature be implemented for other
>> NICs?  I'm *not* asking you to do that, just whether it would be
>> possible.
>> 
>> I'm asking because my review of the QAPI schema depends on the answer.
>> 
>> >> 2. If the former, are you reasonably sure this object will do for other
>> >> NICs?
>> >
>> > No.
>> 
>> I'm not sure I understand you.  Do you mean to say that the feature
>> could be implemented for other NICs, but RxFilterInfo would probably not
>> fit for them?
>
> We will not implement the feature to other NICs, no request.
>
> We notify the management of virtio-net rx-filter change, because
> we want to sync the the rx-filter change to macvtap device.

I understand there are no plans to implement this feature for other
NICs.  But I'm not asking whether we *want* to implement it for other
NICs, I'm asking whether we *could*.

Or rephrased yet another way: what exactly makes this feature applicable
to virtio-net only?

If the answer is "nothing", then we *could* implement it for other NICs.
Else, implementing it for other NICs would be impossible.

Once again, I'm not asking because I want it implemented for other
NICs.  I'm asking because the answer affects my review of the schema.