Commit Graph

10 Commits

Author SHA1 Message Date
Thomas Huth 18d65d2258 net: Allow hubports to connect to other netdevs
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>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2018-01-29 16:05:37 +08:00
Luigi Rizzo 199ee608f0 net: fix qemu_flush_queued_packets() in presence of a hub
When frontend and backend are connected through a hub as below
(showing only one direction), and the frontend (or in general, all
output ports of the hub) cannot accept more traffic, the backend
queues packets in queue-A.

When the frontend (or in general, one output port) becomes ready again,
quemu tries to flush packets from queue-B, which is unfortunately empty.

  e1000.0 <--[queue B]-- hub0port0(hub)hub0port1 <--[queue A]-- tap.0

To fix this i propose to introduce a new function net_hub_flush()
which is called when trying to flush a queue connected to a hub.

Signed-off-by: Luigi Rizzo <rizzo@iet.unipi.it>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-02-27 16:10:23 +01:00
Paolo Bonzini 1422e32db5 net: reorganize headers
Move public headers to include/net, and leave private headers in net/.
Put the virtio headers in include/net/tap.h, removing the multiple copies
that existed.  Leave include/net/tap.h as the interface for NICs, and
net/tap_int.h as the interface for OS-specific parts of the tap backend.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:31:29 +01:00
Paolo Bonzini a245fc1835 net: consolidate NetClientState header files into one
This patch doesn't seem much useful alone, I must admit.  However,
it makes sense as part of the upcoming directory reorganization,
where I want to have include/net/tap.h as the net<->hw interface
for tap.  Then having both net/tap.h and include/net/tap.h does
not work.  "Fixed" by moving all the init functions to a single
header file net/clients.h.

The patch also adopts a uniform style for including net/*.h files
from net/*.c, without the net/ path.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@gmail.com>
2012-10-08 13:59:40 +02:00
Stefan Hajnoczi 4e68f7a081 net: Rename VLANClientState to NetClientState
The vlan feature is no longer part of net core.  Rename VLANClientState
to NetClientState because net clients are not explicitly associated with
a vlan at all, instead they have a peer net client to which they are
connected.

This patch is a mechanical search-and-replace except for a few
whitespace fixups where changing VLANClientState to NetClientState
misaligned whitespace.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
2012-08-01 13:32:10 +01:00
Zhi Yong Wu 606c10e2bd net: Convert qdev_prop_vlan to peer with hub
Instead of using VLANState use net/hub.h to support the vlan qdev
property.  The vlan qdev property becomes an alias for the peer qdev
property but is represented as a VLAN ID number.  When a VLAN ID is
selected the device will really peer with a hub port.

Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
2012-08-01 12:28:51 +01:00
Stefan Hajnoczi 81017645e4 hub: Check that hubs are configured correctly
Checks can be performed to make sure that hubs have at least one NIC and
one host device, warning the user if this is not the case.
Configurations which do not meet this rule tend to be broken but just
emit a warning.  This patch preserves compatibility with the checks
performed by net core on vlans.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
2012-08-01 12:28:51 +01:00
Stefan Hajnoczi 90d87a33c7 net: Look up 'vlan' net clients using hubs
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
2012-08-01 12:28:51 +01:00
Stefan Hajnoczi d33d93b2c4 net: Use hubs for the vlan feature
Stop using the special-case vlan code in net.c.  Instead use the hub net
client to implement the vlan feature.  The next patch will remove vlan
code from net.c completely.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
2012-08-01 12:28:51 +01:00
Stefan Hajnoczi f6c874e300 net: Add a hub net client
The vlan feature can be implemented in terms of hubs.  By introducing a
hub net client it becomes possible to remove the special case vlan code
from net.c and push the vlan feature out of generic networking code.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
2012-08-01 12:28:51 +01:00