It is not obvious from the documentation that using the "port" channel for the console requires telnetd to be installed (see port_connection() in arch/um/drivers/port_user.c). Mention this, and the fact that UML will not boot until a client connects. Signed-off-by: Vincent Whitchurch <vincent.whitchurch@xxxxxxxx> --- Documentation/virt/uml/user_mode_linux_howto_v2.rst | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/Documentation/virt/uml/user_mode_linux_howto_v2.rst b/Documentation/virt/uml/user_mode_linux_howto_v2.rst index 2cafd3c3c6cb..d5ad96c795f6 100644 --- a/Documentation/virt/uml/user_mode_linux_howto_v2.rst +++ b/Documentation/virt/uml/user_mode_linux_howto_v2.rst @@ -664,7 +664,11 @@ one is input, the second one output. * The fd channel - use file descriptor numbers for input/output. Example: ``con1=fd:0,fd:1.`` -* The port channel - listen on TCP port number. Example: ``con1=port:4321`` +* The port channel - start a telnet server on TCP port number. Example: + ``con1=port:4321``. The host must have /usr/sbin/in.telnetd (usually part of + a telnetd package) and the port-helper from the UML utilities (see the + information for the xterm channel below). UML will not boot until a client + connects. * The pty and pts channels - use system pty/pts. -- 2.34.1