" aes-key-wrap=on|off controls support for AES key wrapping (default=on)\n"
" dea-key-wrap=on|off controls support for DEA key wrapping (default=on)\n"
" suppress-vmdesc=on|off disables self-describing migration (default=off)\n"
- " nvdimm=on|off controls NVDIMM support (default=off)\n",
+ " nvdimm=on|off controls NVDIMM support (default=off)\n"
+ " enforce-config-section=on|off enforce configuration section migration (default=off)\n",
QEMU_ARCH_ALL)
STEXI
@item -machine [type=]@var{name}[,prop=@var{value}[,...]]
It is used to uniquely identify this device in other command line directives.
A character device may be used in multiplexing mode by multiple front-ends.
-The key sequence of @key{Control-a} and @key{c} will rotate the input focus
-between attached front-ends. Specify @option{mux=on} to enable this mode.
+Specify @option{mux=on} to enable this mode.
+A multiplexer is a "1:N" device, and here the "1" end is your specified chardev
+backend, and the "N" end is the various parts of QEMU that can talk to a chardev.
+If you create a chardev with @option{id=myid} and @option{mux=on}, QEMU will
+create a multiplexer with your specified ID, and you can then configure multiple
+front ends to use that chardev ID for their input/output. Up to four different
+front ends can be connected to a single multiplexed chardev. (Without
+multiplexing enabled, a chardev can only be used by a single front end.)
+For instance you could use this to allow a single stdio chardev to be used by
+two serial ports and the QEMU monitor:
+
+@example
+-chardev stdio,mux=on,id=char0 \
+-mon chardev=char0,mode=readline,default \
+-serial chardev:char0 \
+-serial chardev:char0
+@end example
+
+You can have more than one multiplexer in a system configuration; for instance
+you could have a TCP port multiplexed between UART 0 and UART 1, and stdio
+multiplexed between the QEMU monitor and a parallel port:
+
+@example
+-chardev stdio,mux=on,id=char0 \
+-mon chardev=char0,mode=readline,default \
+-parallel chardev:char0 \
+-chardev tcp,...,mux=on,id=char1 \
+-serial chardev:char1 \
+-serial chardev:char1
+@end example
+
+When you're using a multiplexed character device, some escape sequences are
+interpreted in the input. @xref{mux_keys, Keys in the character backend
+multiplexer}.
+
+Note that some other command line options may implicitly create multiplexed
+character backends; for instance @option{-serial mon:stdio} creates a
+multiplexed stdio backend connected to the serial port and the QEMU monitor,
+and @option{-nographic} also multiplexes the console and the monitor to
+stdio.
+
+There is currently no support for multiplexing in the other direction
+(where a single QEMU front end takes input and output from multiple chardevs).
Every backend supports the @option{logfile} option, which supplies the path
to a file to record all data transmitted via the backend. The @option{logappend}
ETEXI
DEF("icount", HAS_ARG, QEMU_OPTION_icount, \
- "-icount [shift=N|auto][,align=on|off][,sleep=no,rr=record|replay,rrfile=<filename>]\n" \
+ "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>]\n" \
" enable virtual instruction counter with 2^N clock ticks per\n" \
" instruction, enable aligning the host and virtual clocks\n" \
" or disable real time cpu sleeping\n", QEMU_ARCH_ALL)
time within a few seconds of real time.
When the virtual cpu is sleeping, the virtual time will advance at default
-speed unless @option{sleep=no} is specified.
-With @option{sleep=no}, the virtual time will jump to the next timer deadline
+speed unless @option{sleep=on|off} is specified.
+With @option{sleep=on|off}, the virtual time will jump to the next timer deadline
instantly whenever the virtual cpu goes to sleep mode and will not advance
if no timer is enabled. This behavior give deterministic execution times from
the guest point of view.
projects / qemu.git / blobdiff