system/devices/net.rst

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10 devices or the non-privileged user mode network stack), or to other
25 packages QEMU. By default these are found at ``/etc/qemu-ifup`` and
26 ``/etc/qemu-ifdown`` and are called appropriately when QEMU wants to
29 If QEMU is being run as a non-privileged user you may need properly
43 TAP-Win32. But it is not included in standard QEMU for Windows, so you
50 By using the option ``-net user`` (default configuration if no ``-net``
55         guest (10.0.2.15)  <------>  Firewall/DHCP server <-----> Internet
58                               ---->  DNS server (10.0.2.3)
60                               ---->  SMB server (10.0.2.4)
80 When using the built-in TFTP server, the router is also the TFTP server.
82 When using the ``'-netdev user,hostfwd=...'`` option, TCP or UDP
89 passt_ can be used as a simple replacement for SLIRP (``-net user``).
91 better performance than ``-net user``, full IPv6 support and better security
94 passt_ can be used in the same way as the user backend (using ``-net passt``,
95 ``-netdev passt`` or ``-nic passt``) or it can be launched manually and
96 connected to QEMU either by using a socket (``-netdev stream``) or by using
97 the vhost-user interface (``-netdev vhost-user``).
99 Using ``-netdev stream`` or ``-netdev vhost-user`` will allow the user to
100 enable functionalities not available through the passt backend interface
113 By default, passt will be started in the socket-based mode.
115 .. parsed-literal::
116    |qemu_system| [...OPTIONS...] -nic passt
122 .. parsed-literal::
123    |qemu_system| [...OPTIONS...] -net nic -net passt,tcp-ports=10001,udp-ports=10001
130 .. parsed-literal::
131 …|qemu_system| [...OPTIONS...] -netdev passt,id=netdev0 -device virtio-net,mac=9a:2b:2c:2d:2e:2f,id…
134    virtio0: index=0,type=nic,model=virtio-net-pci,macaddr=9a:2b:2c:2d:2e:2f
137 To use the vhost-based interface, add the ``vhost-user=on`` parameter and
138 select the virtio-net device:
140 .. parsed-literal::
141    |qemu_system| [...OPTIONS...] -nic passt,model=virtio,vhost-user=on
144    virtio-net-pci.0: index=0,type=nic,model=virtio-net-pci,macaddr=52:54:00:12:34:56
145     \ #net006: index=0,type=passt,vhost-user,connected to pid 25731
152    passt --socket ~/passt.socket
154 If ``--socket`` is not provided, passt will print the path of the UNIX domain socket QEMU can conne…
157 .. parsed-literal::
158 …|qemu_system| [...OPTIONS...] -device virtio-net-pci,netdev=netdev0 -netdev stream,id=netdev0,serv…
163 To use vhost-based interface:
166 Start passt with ``--vhost-user``::
168    passt --vhost-user --socket ~/passt.socket
172 .. parsed-literal::
173 …-m $RAMSIZE -chardev socket,id=chr0,path=~/passt.socket -netdev vhost-user,id=netdev0,chardev=chr0…
175 Where ``$RAMSIZE`` is the memory size of your VM ``-m`` and ``-object memory-backend-memfd,size=`` …
180 When passt is connected to QEMU using the vhost-user interface it can
183 As passt runs with no privileges, it relies on passt-repair to save and
185 The passt-repair helper needs to have the CAP_NET_ADMIN capability, or run as root. If passt-repair…
190 Before being able to run passt-repair, the CAP_NET_ADMIN capability must be set
193    setcap cap_net_admin+eip ./passt-repair
197    passt --vhost-user --socket ~/passt_src.socket --repair-path ~/passt-repair_src.socket
199 Where ``~/passt-repair_src.socket`` is the UNIX socket created by passt to
200 communicate with passt-repair. The default value is the ``--socket`` path
203 Start passt-repair::
205    passt-repair ~/passt-repair_src.socket
209 .. parsed-literal::
210    |qemu_system| [...OPTIONS...] [...VHOST USER OPTIONS...] -monitor stdio
214    passt --vhost-user --socket ~/passt_dst.socket --repair-path ~/passt-repair_dst.socket
216 Start passt-repair::
218    passt-repair ~/passt-repair_dst.socket
220 Start QEMU with the ``-incoming`` parameter:
222 .. parsed-literal::
223    |qemu_system| [...OPTIONS...] [...VHOST USER OPTIONS...] -incoming tcp:localhost:4444
229 A separate passt-repair instance must be started for every migration. In the case of a failed migra…
239 such a hub using the ``-netdev
240 hubport`` or ``-nic hubport`` options. The legacy ``-net`` option also
242 default hub) unless you specify a netdev with ``-net nic,netdev=xxx``
248 Using the ``-netdev socket`` (or ``-nic socket`` or ``-net socket``)
250 QEMU instances. See the description of the ``-netdev socket`` option in