system/devices/net.rst

4 -----------------
9 connect the NIC of the guest to a real network (e.g. by using a TAP
10 devices or the non-privileged user mode network stack), or to other
11 guest instances running in another QEMU process (e.g. by using the
24 As an example, you can download the ``linux-test-xxx.tar.gz`` archive
25 and copy the script ``qemu-ifup`` in ``/etc`` and configure properly
26 ``sudo`` so that the command ``ifconfig`` contained in ``qemu-ifup`` can
37 TAP-Win32. But it is not included in standard QEMU for Windows, so you
44 By using the option ``-net user`` (default configuration if no ``-net``
49         guest (10.0.2.15)  <------>  Firewall/DHCP server <-----> Internet
52                               ---->  DNS server (10.0.2.3)
54                               ---->  SMB server (10.0.2.4)
74 When using the built-in TFTP server, the router is also the TFTP server.
76 When using the ``'-netdev user,hostfwd=...'`` option, TCP or UDP
77 connections can be redirected from the host to the guest. It allows for
83 passt_ can be used as a simple replacement for SLIRP (``-net user``).
85 better performance than ``-net user``, full IPv6 support and better security
89 (``-netdev stream``) or using the vhost-user interface (``-netdev vhost-user``).
100    passt --socket ~/passt.socket
102 If ``--socket`` is not provided, passt will print the path of the UNIX domain socket QEMU can conne…
105 .. parsed-literal::
106 …|qemu_system| [...OPTIONS...] -device virtio-net-pci,netdev=netdev0 -netdev stream,id=netdev0,serv…
111 To use vhost-based interface:
114 Start passt with ``--vhost-user``::
116    passt --vhost-user --socket ~/passt.socket
120 .. parsed-literal::
121 …-m $RAMSIZE -chardev socket,id=chr0,path=~/passt.socket -netdev vhost-user,id=netdev0,chardev=chr0…
123 Where ``$RAMSIZE`` is the memory size of your VM ``-m`` and ``-object memory-backend-memfd,size=`` …
128 When passt is connected to QEMU using the vhost-user interface it can
131 As passt runs with no privileges, it relies on passt-repair to save and
133 The passt-repair helper needs to have the CAP_NET_ADMIN capability, or run as root. If passt-repair…
135 Example of migration of a guest on the same host
138 Before being able to run passt-repair, the CAP_NET_ADMIN capability must be set
141    setcap cap_net_admin+eip ./passt-repair
143 Start passt for the source side::
145    passt --vhost-user --socket ~/passt_src.socket --repair-path ~/passt-repair_src.socket
147 Where ``~/passt-repair_src.socket`` is the UNIX socket created by passt to
148 communicate with passt-repair. The default value is the ``--socket`` path
151 Start passt-repair::
153    passt-repair ~/passt-repair_src.socket
155 Start source side QEMU with a monitor to be able to send the migrate command:
157 .. parsed-literal::
158    |qemu_system| [...OPTIONS...] [...VHOST USER OPTIONS...] -monitor stdio
160 Start passt for the destination side::
162    passt --vhost-user --socket ~/passt_dst.socket --repair-path ~/passt-repair_dst.socket
164 Start passt-repair::
166    passt-repair ~/passt-repair_dst.socket
168 Start QEMU with the ``-incoming`` parameter:
170 .. parsed-literal::
171    |qemu_system| [...OPTIONS...] [...VHOST USER OPTIONS...] -incoming tcp:localhost:4444
173 Then in the source guest monitor the migration can be started::
177 A separate passt-repair instance must be started for every migration. In the case of a failed migra…
186 (TAP devices). You can connect guest NICs or host network backends to
187 such a hub using the ``-netdev
188 hubport`` or ``-nic hubport`` options. The legacy ``-net`` option also
190 default hub) unless you specify a netdev with ``-net nic,netdev=xxx``
196 Using the ``-netdev socket`` (or ``-nic socket`` or ``-net socket``)
198 QEMU instances. See the description of the ``-netdev socket`` option in