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

[Jason Wang]

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 <address@hidden>
> > > ---
> > >    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