For the long time QEMU has support for UDP unicast network backend added by commit 0e0e7facc775e9, but manual was missing description and usage examples.
Changes from v1: Address comments by Michael S. Tsirkin: - remove superfluous empty lines. - place the note about two QEMU instances after the example. - English and others cleanups. Signed-off-by: Victor Kaplansky <vict...@redhat.com> --- qemu-options.hx | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/qemu-options.hx b/qemu-options.hx index 2485b94..6bdb884 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -1907,6 +1907,28 @@ qemu-system-i386 linux.img \ -net socket,mcast=239.192.168.1:1102,localaddr=1.2.3.4 @end example +@item -netdev socket,id=@var{id}[,fd=@var{h}][,udp=@var{rhost}:@var{rport}[,localaddr=@var{lhost}:@var{lport}]] +@itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,udp=@var{rhost}:@var{rport}[,localaddr=@var{rhost}:@var{lport}]] + +Connect a VLAN @var{n} to a remote VLAN in another QEMU virtual +machine using a UDP tunnel. Use lhost:lport as the local host and +port, rhost:rport as the remote host and port of the tunnel. Use +@option{fd=h} to specify an already opened UDP socket. + +Example: +@example +# launch one QEMU instance +qemu-system-i386 linux.img \ + -device virtio-net-pci,netdev=net0 \ + -netdev socket,id=net0,udp=localhost:4444,localaddr=localhost:5555 +# launch a second QEMU instance sharing the network with the first one +qemu-system-i386 linux.img \ + -device virtio-net-pci,netdev=net0 \ + -netdev socket,id=net0,udp=localhost:5555,localaddr=localhost:4444 + +NOTE: The two QEMU instances can be running on different hosts. +@end example + @item -netdev l2tpv3,id=@var{id},src=@var{srcaddr},dst=@var{dstaddr}[,srcport=@var{srcport}][,dstport=@var{dstport}],txsession=@var{txsession}[,rxsession=@var{rxsession}][,ipv6][,udp][,cookie64][,counter][,pincounter][,txcookie=@var{txcookie}][,rxcookie=@var{rxcookie}][,offset=@var{offset}] @itemx -net l2tpv3[,vlan=@var{n}][,name=@var{name}],src=@var{srcaddr},dst=@var{dstaddr}[,srcport=@var{srcport}][,dstport=@var{dstport}],txsession=@var{txsession}[,rxsession=@var{rxsession}][,ipv6][,udp][,cookie64][,counter][,pincounter][,txcookie=@var{txcookie}][,rxcookie=@var{rxcookie}][,offset=@var{offset}] Connect VLAN @var{n} to L2TPv3 pseudowire. L2TPv3 (RFC3391) is a popular -- --Victor