Re: [Qemu-devel] [PATCH v2] net: Allow hubports to connect to other netdevs

[Jason Wang <jasowang@redhat.com>]

On 2018年01月16日 03:50, Thomas Huth wrote:
> QEMU can emulate hubs to connect NICs and netdevs. This is currently
> primarily used for the mis-named 'vlan' feature of the networking
> subsystem. Now the 'vlan' feature has been marked as deprecated, since
> its name is rather confusing and the users often rather mis-configure
> their network when trying to use it. But while the 'vlan' parameter
> should be removed at one point in time, the basic idea of emulating
> a hub in QEMU is still good: It's useful for bundling up the output of
> multiple NICs into one single l2tp netdev for example.
>
> Now to be able to use the hubport feature without 'vlan's, there is one
> missing piece: The possibility to connect a hubport to a netdev, too.
> This patch adds this possibility by introducing a new "netdev=..."
> parameter to the hubports.
>
> To bundle up the output of multiple NICs into one socket netdev, you can
> now run QEMU with these parameters for example:
>
> qemu-system-ppc64 ... -netdev socket,id=s1,connect=:11122 \
>      -netdev hubport,hubid=1,id=h1,netdev=s1 \
>      -netdev hubport,hubid=1,id=h2 -device e1000,netdev=h2 \
>      -netdev hubport,hubid=1,id=h3 -device virtio-net-pci,netdev=h3
>
> For using the socket netdev, you have got to start another QEMU as the
> receiving side first, for example with network dumping enabled:
>
> qemu-system-x86_64 -M isapc -netdev socket,id=s0,listen=:11122 \
>      -device ne2k_isa,netdev=s0 \
>      -object filter-dump,id=f1,netdev=s0,file=/tmp/dump.dat
>
> After the ppc64 guest tried to boot from both NICs, you can see in the
> dump file (using Wireshark, for example), that the output of both NICs
> (the e1000 and the virtio-net-pci) has been successfully transfered
> via the socket netdev in this case.
>
> Suggested-by: Paolo Bonzini<pbonzini@redhat.com>
> Signed-off-by: Thomas Huth<thuth@redhat.com>
> ---
>   v2: Set up peer via qemu_new_net_client() instead of duplicating the
>       code to do this in net_init_hubport()

Applied.

Thanks