Il 09/06/2012 05:04, Zhi Yong Wu ha scritto:
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
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 :(.
To be honest, i am concerned if anyone uses this syntax. Since the
feature will finally be discarded, i suggest that we don't support
this now. If someone complains this later, we can fix it. If nobody
complains, that is what we hope.
I think you're missing the big picture of this series, which is exactly
_not_ to discard the VLAN feature, but just to rewrite it in a better way.
That said, I agree that this is a somewhat fringe usage; most people
will use -net nic,model=virtio,vlan=1 rather than "-device". We may get
by with dropping it. I have no strong opinion either way.