swh:1:snp:173f8deb0c56c557784b4fd217e7608ac6197844
Tip revision: 219d54332a09e8d8741c1e1982f5eae56099de85 authored by Linus Torvalds on 25 November 2019, 00:32:01 UTC
Linux 5.4
Linux 5.4
Tip revision: 219d543
Kconfig
# SPDX-License-Identifier: GPL-2.0
menu "UML Character Devices"
config STDERR_CONSOLE
bool "stderr console"
default y
help
console driver which dumps all printk messages to stderr.
config SSL
bool "Virtual serial line"
help
The User-Mode Linux environment allows you to create virtual serial
lines on the UML that are usually made to show up on the host as
ttys or ptys.
See <http://user-mode-linux.sourceforge.net/old/input.html> for more
information and command line examples of how to use this facility.
Unless you have a specific reason for disabling this, say Y.
config NULL_CHAN
bool "null channel support"
help
This option enables support for attaching UML consoles and serial
lines to a device similar to /dev/null. Data written to it disappears
and there is never any data to be read.
config PORT_CHAN
bool "port channel support"
help
This option enables support for attaching UML consoles and serial
lines to host portals. They may be accessed with 'telnet <host>
<port number>'. Any number of consoles and serial lines may be
attached to a single portal, although what UML device you get when
you telnet to that portal will be unpredictable.
It is safe to say 'Y' here.
config PTY_CHAN
bool "pty channel support"
help
This option enables support for attaching UML consoles and serial
lines to host pseudo-terminals. Access to both traditional
pseudo-terminals (/dev/pty*) and pts pseudo-terminals are controlled
with this option. The assignment of UML devices to host devices
will be announced in the kernel message log.
It is safe to say 'Y' here.
config TTY_CHAN
bool "tty channel support"
help
This option enables support for attaching UML consoles and serial
lines to host terminals. Access to both virtual consoles
(/dev/tty*) and the slave side of pseudo-terminals (/dev/ttyp* and
/dev/pts/*) are controlled by this option.
It is safe to say 'Y' here.
config XTERM_CHAN
bool "xterm channel support"
help
This option enables support for attaching UML consoles and serial
lines to xterms. Each UML device so assigned will be brought up in
its own xterm.
It is safe to say 'Y' here.
config NOCONFIG_CHAN
bool
default !(XTERM_CHAN && TTY_CHAN && PTY_CHAN && PORT_CHAN && NULL_CHAN)
config CON_ZERO_CHAN
string "Default main console channel initialization"
default "fd:0,fd:1"
help
This is the string describing the channel to which the main console
will be attached by default. This value can be overridden from the
command line. The default value is "fd:0,fd:1", which attaches the
main console to stdin and stdout.
It is safe to leave this unchanged.
config CON_CHAN
string "Default console channel initialization"
default "xterm"
help
This is the string describing the channel to which all consoles
except the main console will be attached by default. This value can
be overridden from the command line. The default value is "xterm",
which brings them up in xterms.
It is safe to leave this unchanged, although you may wish to change
this if you expect the UML that you build to be run in environments
which don't have X or xterm available.
config SSL_CHAN
string "Default serial line channel initialization"
default "pty"
help
This is the string describing the channel to which the serial lines
will be attached by default. This value can be overridden from the
command line. The default value is "pty", which attaches them to
traditional pseudo-terminals.
It is safe to leave this unchanged, although you may wish to change
this if you expect the UML that you build to be run in environments
which don't have a set of /dev/pty* devices.
config UML_SOUND
tristate "Sound support"
help
This option enables UML sound support. If enabled, it will pull in
soundcore and the UML hostaudio relay, which acts as a intermediary
between the host's dsp and mixer devices and the UML sound system.
It is safe to say 'Y' here.
config SOUND
tristate
default UML_SOUND
config SOUND_OSS_CORE
bool
default UML_SOUND
config HOSTAUDIO
tristate
default UML_SOUND
endmenu
menu "UML Network Devices"
depends on NET
# UML virtual driver
config UML_NET
bool "Virtual network device"
help
While the User-Mode port cannot directly talk to any physical
hardware devices, this choice and the following transport options
provide one or more virtual network devices through which the UML
kernels can talk to each other, the host, and with the host's help,
machines on the outside world.
For more information, including explanations of the networking and
sample configurations, see
<http://user-mode-linux.sourceforge.net/old/networking.html>.
If you'd like to be able to enable networking in the User-Mode
linux environment, say Y; otherwise say N. Note that you must
enable at least one of the following transport options to actually
make use of UML networking.
config UML_NET_ETHERTAP
bool "Ethertap transport"
depends on UML_NET
help
The Ethertap User-Mode Linux network transport allows a single
running UML to exchange packets with its host over one of the
host's Ethertap devices, such as /dev/tap0. Additional running
UMLs can use additional Ethertap devices, one per running UML.
While the UML believes it's on a (multi-device, broadcast) virtual
Ethernet network, it's in fact communicating over a point-to-point
link with the host.
To use this, your host kernel must have support for Ethertap
devices. Also, if your host kernel is 2.4.x, it must have
CONFIG_NETLINK_DEV configured as Y or M.
For more information, see
<http://user-mode-linux.sourceforge.net/old/networking.html> That site
has examples of the UML command line to use to enable Ethertap
networking.
If you'd like to set up an IP network with the host and/or the
outside world, say Y to this, the Daemon Transport and/or the
Slip Transport. You'll need at least one of them, but may choose
more than one without conflict. If you don't need UML networking,
say N.
config UML_NET_TUNTAP
bool "TUN/TAP transport"
depends on UML_NET
help
The UML TUN/TAP network transport allows a UML instance to exchange
packets with the host over a TUN/TAP device. This option will only
work with a 2.4 host, unless you've applied the TUN/TAP patch to
your 2.2 host kernel.
To use this transport, your host kernel must have support for TUN/TAP
devices, either built-in or as a module.
config UML_NET_SLIP
bool "SLIP transport"
depends on UML_NET
help
The slip User-Mode Linux network transport allows a running UML to
network with its host over a point-to-point link. Unlike Ethertap,
which can carry any Ethernet frame (and hence even non-IP packets),
the slip transport can only carry IP packets.
To use this, your host must support slip devices.
For more information, see
<http://user-mode-linux.sourceforge.net/old/networking.html>.
has examples of the UML command line to use to enable slip
networking, and details of a few quirks with it.
The Ethertap Transport is preferred over slip because of its
limitations. If you prefer slip, however, say Y here. Otherwise
choose the Multicast transport (to network multiple UMLs on
multiple hosts), Ethertap (to network with the host and the
outside world), and/or the Daemon transport (to network multiple
UMLs on a single host). You may choose more than one without
conflict. If you don't need UML networking, say N.
config UML_NET_DAEMON
bool "Daemon transport"
depends on UML_NET
help
This User-Mode Linux network transport allows one or more running
UMLs on a single host to communicate with each other, but not to
the host.
To use this form of networking, you'll need to run the UML
networking daemon on the host.
For more information, see
<http://user-mode-linux.sourceforge.net/old/networking.html> That site
has examples of the UML command line to use to enable Daemon
networking.
If you'd like to set up a network with other UMLs on a single host,
say Y. If you need a network between UMLs on multiple physical
hosts, choose the Multicast Transport. To set up a network with
the host and/or other IP machines, say Y to the Ethertap or Slip
transports. You'll need at least one of them, but may choose
more than one without conflict. If you don't need UML networking,
say N.
config UML_NET_VECTOR
bool "Vector I/O high performance network devices"
depends on UML_NET
help
This User-Mode Linux network driver uses multi-message send
and receive functions. The host running the UML guest must have
a linux kernel version above 3.0 and a libc version > 2.13.
This driver provides tap, raw, gre and l2tpv3 network transports
with up to 4 times higher network throughput than the UML network
drivers.
config UML_NET_VDE
bool "VDE transport"
depends on UML_NET
help
This User-Mode Linux network transport allows one or more running
UMLs on a single host to communicate with each other and also
with the rest of the world using Virtual Distributed Ethernet,
an improved fork of uml_switch.
You must have libvdeplug installed in order to build the vde
transport into UML.
To use this form of networking, you will need to run vde_switch
on the host.
For more information, see <http://wiki.virtualsquare.org/>
That site has a good overview of what VDE is and also examples
of the UML command line to use to enable VDE networking.
If you need UML networking with VDE,
say Y.
config UML_NET_MCAST
bool "Multicast transport"
depends on UML_NET
help
This Multicast User-Mode Linux network transport allows multiple
UMLs (even ones running on different host machines!) to talk to
each other over a virtual ethernet network. However, it requires
at least one UML with one of the other transports to act as a
bridge if any of them need to be able to talk to their hosts or any
other IP machines.
To use this, your host kernel(s) must support IP Multicasting.
For more information, see
<http://user-mode-linux.sourceforge.net/old/networking.html> That site
has examples of the UML command line to use to enable Multicast
networking, and notes about the security of this approach.
If you need UMLs on multiple physical hosts to communicate as if
they shared an Ethernet network, say Y. If you need to communicate
with other IP machines, make sure you select one of the other
transports (possibly in addition to Multicast; they're not
exclusive). If you don't need to network UMLs say N to each of
the transports.
config UML_NET_PCAP
bool "pcap transport"
depends on UML_NET
help
The pcap transport makes a pcap packet stream on the host look
like an ethernet device inside UML. This is useful for making
UML act as a network monitor for the host. You must have libcap
installed in order to build the pcap transport into UML.
For more information, see
<http://user-mode-linux.sourceforge.net/old/networking.html> That site
has examples of the UML command line to use to enable this option.
If you intend to use UML as a network monitor for the host, say
Y here. Otherwise, say N.
config UML_NET_SLIRP
bool "SLiRP transport"
depends on UML_NET
help
The SLiRP User-Mode Linux network transport allows a running UML
to network by invoking a program that can handle SLIP encapsulated
packets. This is commonly (but not limited to) the application
known as SLiRP, a program that can re-socket IP packets back onto
he host on which it is run. Only IP packets are supported,
unlike other network transports that can handle all Ethernet
frames. In general, slirp allows the UML the same IP connectivity
to the outside world that the host user is permitted, and unlike
other transports, SLiRP works without the need of root level
privleges, setuid binaries, or SLIP devices on the host. This
also means not every type of connection is possible, but most
situations can be accommodated with carefully crafted slirp
commands that can be passed along as part of the network device's
setup string. The effect of this transport on the UML is similar
that of a host behind a firewall that masquerades all network
connections passing through it (but is less secure).
To use this you should first have slirp compiled somewhere
accessible on the host, and have read its documentation. If you
don't need UML networking, say N.
Startup example: "eth0=slirp,FE:FD:01:02:03:04,/usr/local/bin/slirp"
endmenu
config VIRTIO_UML
tristate "UML driver for virtio devices"
select VIRTIO
help
This driver provides support for virtio based paravirtual device
drivers over vhost-user sockets.