@node pcsys_network
@section Network emulation
-QEMU can simulate several network cards (PCI or ISA cards on the PC
-target) and can connect them to an arbitrary number of Virtual Local
-Area Networks (VLANs). Host TAP devices can be connected to any QEMU
-VLAN. VLAN can be connected between separate instances of QEMU to
-simulate large networks. For simpler usage, a non privileged user mode
-network stack can replace the TAP device to have a basic network
-connection.
-
-@subsection VLANs
-
-QEMU simulates several VLANs. A VLAN can be symbolised as a virtual
-connection between several network devices. These devices can be for
-example QEMU virtual Ethernet cards or virtual Host ethernet devices
-(TAP devices).
+QEMU can simulate several network cards (e.g. PCI or ISA cards on the PC
+target) and can connect them to a network backend on the host or an emulated
+hub. The various host network backends can either be used to connect the NIC of
+the guest to a real network (e.g. by using a TAP devices or the non-privileged
+user mode network stack), or to other guest instances running in another QEMU
+process (e.g. by using the socket host network backend).
@subsection Using TAP network interfaces
@example
- QEMU VLAN <------> Firewall/DHCP server <-----> Internet
+ guest (10.0.2.15) <------> Firewall/DHCP server <-----> Internet
| (10.0.2.2)
|
----> DNS server (10.0.2.3)
connections can be redirected from the host to the guest. It allows for
example to redirect X11, telnet or SSH connections.
-@subsection Connecting VLANs between QEMU instances
+@subsection Hubs
+
+QEMU can simulate several hubs. A hub can be thought of as a virtual connection
+between several network devices. These devices can be for example QEMU virtual
+ethernet cards or virtual Host ethernet devices (TAP devices). You can connect
+guest NICs or host network backends to such a hub using the @option{-netdev
+hubport} or @option{-nic hubport} options. The legacy @option{-net} option
+also connects the given device to the emulated hub with ID 0 (i.e. the default
+hub) unless you specify a netdev with @option{-net nic,netdev=xxx} here.
-Using the @option{-net socket} option, it is possible to make VLANs
-that span several QEMU instances. See @ref{sec_invocation} to have a
-basic example.
+@subsection Connecting emulated networks between QEMU instances
+
+Using the @option{-netdev socket} (or @option{-nic socket} or
+@option{-net socket}) option, it is possible to create emulated
+networks that span several QEMU instances.
+See the description of the @option{-netdev socket} option in the
+@ref{sec_invocation,,Invocation chapter} to have a basic example.
@node pcsys_other_devs
@section Other Devices
(for embedded NICs). The new syntax allows different settings to be
provided per NIC.
-@subsection -net vlan (since 2.9.0)
-
-The ``-net vlan=NN'' argument was mostly used to attach separate
-network backends to different virtual NICs. This is the default
-behavior for ``-netdev'' and ``-nic''. You can connect multiple
-``-netdev'' and ``-nic'' devices to the same network using the
-"hubport" network backend, created with ``-netdev hubport,hubid=NN,...''
-and ``-nic hubport,hubid=NN''.
-
-@subsection -drive cyls=...,heads=...,secs=...,trans=... (since 2.10.0)
-
-The drive geometry arguments are replaced by the the geometry arguments
-that can be specified with the ``-device'' parameter.
-
-@subsection -drive serial=... (since 2.10.0)
-
-The drive serial argument is replaced by the the serial argument
-that can be specified with the ``-device'' parameter.
-
-@subsection -drive addr=... (since 2.10.0)
-
-The drive addr argument is replaced by the the addr argument
-that can be specified with the ``-device'' parameter.
-
@subsection -usbdevice (since 2.10.0)
The ``-usbdevice DEV'' argument is now a synonym for setting
The @code{-startdate} option has been replaced by @code{-rtc base=@var{date}}.
-@subsection -virtioconsole (since 2.13.0)
+@subsection -virtioconsole (since 3.0.0)
Option @option{-virtioconsole} has been replaced by
@option{-device virtconsole}.
-@section qemu-img command line arguments
+@subsection -clock (since 3.0.0)
+
+The @code{-clock} option is ignored since QEMU version 1.7.0. There is no
+replacement since it is not needed anymore.
-@subsection convert -s (since 2.0.0)
+@subsection -enable-hax (since 3.0.0)
-The ``convert -s snapshot_id_or_name'' argument is obsoleted
-by the ``convert -l snapshot_param'' argument instead.
+The @option{-enable-hax} option has been replaced by @option{-accel hax}.
+Both options have been introduced in QEMU version 2.9.0.
@section QEMU Machine Protocol (QMP) commands
The ``query-cpus'' command is replaced by the ``query-cpus-fast'' command.
-@subsection query-cpus-fast "arch" output member (since 2.13.0)
+@subsection query-cpus-fast "arch" output member (since 3.0.0)
The ``arch'' output member of the ``query-cpus-fast'' command is
replaced by the ``target'' output member.
@section System emulator machines
-@subsection Xilinx EP108 (since 2.11.0)
+@subsection pc-0.10 and pc-0.11 (since 3.0)
-The ``xlnx-ep108'' machine has been replaced by the ``xlnx-zcu102'' machine.
-The ``xlnx-zcu102'' machine has the same features and capabilites in QEMU.
+These machine types are very old and likely can not be used for live migration
+from old QEMU versions anymore. A newer machine type should be used instead.
-@section Block device options
+@section Device options
-@subsection "backing": "" (since 2.12.0)
+@subsection Block device options
+
+@subsubsection "backing": "" (since 2.12.0)
In order to prevent QEMU from automatically opening an image's backing
chain, use ``"backing": null'' instead.
+@subsection vio-spapr-device device options
+
+@subsubsection "irq": "" (since 3.0.0)
+
+The ``irq'' property is obsoleted.
+
@node Supported build platforms
@appendix Supported build platforms
projects / qemu.git / blobdiff