Re: [Qemu-devel] [PATCH] net: Mark 'vlan' parameter as deprecated

[Jason Wang <jasowang@redhat.com>]

On 2017年01月25日 15:54, Thomas Huth wrote:
> On 25.01.2017 08:50, Jason Wang wrote:
>>
>> On 2017年01月24日 17:42, Thomas Huth wrote:
>>> The 'vlan' parameter is a continuous source of confusion for the users,
>>> many people mix it up with the more common term VLAN (the link layer
>>> packet encapsulation), and even if they realize that the QEMU 'vlan' is
>>> rather some kind of network hub emulation, there is still a high risk
>>> that they configure their QEMU networking in a wrong way with this
>>> parameter (e.g. by hooking NICs together, so they get a 'loopback'
>>> between one and the other NIC).
>>> Thus at one point in time, we should finally get rid of the 'vlan'
>>> feature in QEMU. Let's do a first step in this direction by declaring
>>> the 'vlan' parameter as deprecated and informing the users to use the
>>> 'netdev' parameter instead.
>>>
>>> Signed-off-by: Thomas Huth <thuth@redhat.com>
>>> ---
>>>    net/net.c | 6 ++++++
>>>    1 file changed, 6 insertions(+)
>>>
>>> diff --git a/net/net.c b/net/net.c
>>> index 939fe31..fb7af3a 100644
>>> --- a/net/net.c
>>> +++ b/net/net.c
>>> @@ -970,6 +970,7 @@ static int net_client_init1(const void *object,
>>> bool is_netdev, Error **errp)
>>>        const Netdev *netdev;
>>>        const char *name;
>>>        NetClientState *peer = NULL;
>>> +    static bool vlan_warned;
>>>          if (is_netdev) {
>>>            netdev = object;
>>> @@ -1050,6 +1051,11 @@ static int net_client_init1(const void *object,
>>> bool is_netdev, Error **errp)
>>>                !opts->u.nic.data->has_netdev) {
>>>                peer = net_hub_add_port(net->has_vlan ? net->vlan : 0,
>>> NULL);
>>>            }
>>> +
>>> +        if (net->has_vlan && !vlan_warned) {
>>> +            error_report("'vlan' is deprecated. Please use 'netdev'
>>> instead.");
>>> +            vlan_warned = true;
>>> +        }
>>>        }
>>>          if (net_client_init_fun[netdev->type](netdev, name, peer,
>>> errp) < 0) {
>> Looks good, but do really want only warn once? Consider we have monitor
>> command e.g "host_net_add".
> I don't mind ... I can remove the "vlan_warned" check, but then you'll
> get a lot of error messages at once if you start QEMU with multiple
> "-net" parameters that use "vlan=...". Is that ok for you? If yes, I'll
> send an updated v2 of my patch without that "vlan_warned" check.
>
>   Thomas
>

You're right, this version looks better, applied to -net.

Thanks