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

[Stefan Hajnoczi <stefanha@gmail.com>]

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
> 
> 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.  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
-net option and NICs need this".

> 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