Re: [Qemu-devel] [PATCH v4 06/16] net: Remove vlan qdev property

[Stefan Hajnoczi]

On Fri, Jun 8, 2012 at 3:48 PM, Zhi Yong Wu <address@hidden> wrote:
> On Fri, Jun 8, 2012 at 9:23 PM, Stefan Hajnoczi <address@hidden> wrote:
>> On Mon, Jun 4, 2012 at 6:29 AM,  <address@hidden> wrote:
>>> From: Stefan Hajnoczi <address@hidden>
>>>
>>> The vlan feature is implemented using hubs and no longer uses
>>> special-purpose VLANState structs that are accessible as qdev
>>> properties.
>>>
>>> Signed-off-by: Stefan Hajnoczi <address@hidden>
>>> Signed-off-by: Zhi Yong Wu <address@hidden>
>>> ---
>>>  hw/qdev-properties.c |   72 
>>> --------------------------------------------------
>>>  hw/qdev.c            |    2 -
>>>  hw/qdev.h            |    4 ---
>>>  net.h                |    3 --
>>>  4 files changed, 0 insertions(+), 81 deletions(-)
>>
>> This commit looks suspicious because it removes a user-visible qdev
>> property but we're trying to preserve backward compatibility.  This
>> command-line will break:
>>
>> x86_64-softmmu/qemu-system-x86_64 -net user,vlan=1 -device 
>> virtio-net-pci,vlan=1
> Should this type of syntax be supported? i know this at the first time
>>
>> Instead of dropping the qdev_prop_vlan completely the
>> hw/qdev-properties.c code needs to call net/hub.h external functions
>> to implement equivalent functionality:
>>
>> 1. Setting the vlan=<id> property looks up the hub port and assigns
>> the NICConf->peer field.
>> 2. Getting the vlan property looks up the hub id (i.e. vlan id) given
>> the peer.  If the peer is not a hub port the result is -1.
>>
>> When I wrote this patch I missed the big picture and forgot about
>> backwards compatibility :(.
>>
>> Do you feel comfortable rewriting this commit?
> Do you mean that you would like to rewrite this by yourself?

No, I meant do you agree with the changes that I suggested?  I wanted
to make sure that you understand the problem that I'm describing and
how it could be solved.

Stefan