Re: [Qemu-devel] [PATCH] net: make nic name unique

[Markus Armbruster <armbru@redhat.com>]

Stefan Hajnoczi <stefanha@gmail.com> writes:

> On Thu, Apr 11, 2013 at 07:58:39PM +0800, Amos Kong wrote:
>> If we don't assign 'id' for nic device, device's name will be $model.$idx.
>> The $idx is always 0 if we use new style of cmdline. This problem was
>> introduced by commit d33d93b2.
>> 
>> eg:
>>  # qemu-upstream -device virtio-net-pci,netdev=h1 -netdev tap,id=h1 \
>>                     -device virtio-net-pci,netdev=h2 -netdev tap,id=h2 ..
>>  (qemu) info network
>>  virtio-net-pci.0: index=0,type=nic,model=virtio-net-pci,macaddr=52:54:00:12:34:56
>>   \ h1: index=0,type=tap,ifname=tap0,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown
>>  virtio-net-pci.0: index=0,type=nic,model=virtio-net-pci,macaddr=52:54:00:12:34:57
>>   \ h2: index=0,type=tap,ifname=tap1,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown

There are two kinds of names around here: network client names and
device (qdev) IDs.  Commit message could be tweaked to make it clearer
that this is about network client names.

As a general rule in QEMU, we call all objects "device", and all classes
"driver" %-/

>> 
>> This patch remove the check of hub, allocate increased id for all devices
>> that have same model.
>>
>> Signed-off-by: Amos Kong <akong@redhat.com>
>> ---
>>  net/net.c | 3 +--
>>  1 file changed, 1 insertion(+), 2 deletions(-)
>
> I looked a bit more into this.  Markus added NIC naming in
> 53e51d85ef1fdd295c8f09792b8e7490c148f4b3.

Added it to non-VLAN clients, actually.  It already existed for VLAN
clients.

>                                            Please include this commit ID
> in the commit message.
>
> My hub patches incorrectly dropped Markus' fix and I actually documented
> this:
>
> +/**
> + * Generate a name for net client
> + *
> + * Only net clients created with the legacy -net option need this.
> Naming is
> + * mandatory for net clients created with -netdev.
> + */
>  static char *assign_name(VLANClientState *vc1, const char *model)
>
> Please update this comment to say "Only net clients created with the legacy
>
>> diff --git a/net/net.c b/net/net.c
>> index 67032f5..631e7d0 100644
>> --- a/net/net.c
>> +++ b/net/net.c
>> @@ -171,8 +171,7 @@ static char *assign_name(NetClientState *nc1, const char *model)
>>              continue;
>>          }
>>          /* For compatibility only bump id for net clients on a vlan */
>> -        if (strcmp(nc->model, model) == 0 &&
>> -            net_hub_id_for_client(nc, NULL) == 0) {
>> +        if (strcmp(nc->model, model) == 0) {
>>              id++;
>>          }
>
> Please delete the incorrect comment about compatibility when dropping the
> net_hub_id_for_client() call.
>
> Stefan