| Message ID | 20241016102605.459395-9-r.peniaev@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | chardev: implement backend chardev multiplexing | expand |
Hi On Wed, Oct 16, 2024 at 2:28 PM Roman Penyaev <r.peniaev@gmail.com> wrote: > > This adds a few lines describing `mux-be` multiplexer configuration > for multiplexing several backend devices with a single frontend > device. > > Signed-off-by: Roman Penyaev <r.peniaev@gmail.com> > Cc: "Marc-André Lureau" <marcandre.lureau@redhat.com> > Cc: qemu-devel@nongnu.org > --- > qemu-options.hx | 78 ++++++++++++++++++++++++++++++++++++------------- > 1 file changed, 58 insertions(+), 20 deletions(-) > > diff --git a/qemu-options.hx b/qemu-options.hx > index daae49414740..dd5dfe8596f0 100644 > --- a/qemu-options.hx > +++ b/qemu-options.hx > @@ -3677,37 +3677,37 @@ DEFHEADING(Character device options:) > > DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, > "-chardev help\n" > - "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" > + "-chardev null,id=id[,mux=on|off][,mux-be-id=id][,logfile=PATH][,logappend=on|off]\n" > "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4=on|off][,ipv6=on|off][,nodelay=on|off]\n" > - " [,server=on|off][,wait=on|off][,telnet=on|off][,websocket=on|off][,reconnect=seconds][,mux=on|off]\n" > + " [,server=on|off][,wait=on|off][,telnet=on|off][,websocket=on|off][,reconnect=seconds][,mux=on|off][,mux-be-id=id]\n" > " [,logfile=PATH][,logappend=on|off][,tls-creds=ID][,tls-authz=ID] (tcp)\n" > "-chardev socket,id=id,path=path[,server=on|off][,wait=on|off][,telnet=on|off][,websocket=on|off][,reconnect=seconds]\n" > - " [,mux=on|off][,logfile=PATH][,logappend=on|off][,abstract=on|off][,tight=on|off] (unix)\n" > + " [,mux=on|off][,mux-be-id=id][,logfile=PATH][,logappend=on|off][,abstract=on|off][,tight=on|off] (unix)\n" > "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n" > - " [,localport=localport][,ipv4=on|off][,ipv6=on|off][,mux=on|off]\n" > + " [,localport=localport][,ipv4=on|off][,ipv6=on|off][,mux=on|off][,mux-be-id=id]\n" > " [,logfile=PATH][,logappend=on|off]\n" > - "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" > + "-chardev msmouse,id=id[,mux=on|off][,mux-be-id=id][,logfile=PATH][,logappend=on|off]\n" > "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n" > - " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n" > + " [,mux=on|off][,mux-be-id=id][,logfile=PATH][,logappend=on|off]\n" > "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n" > - "-chardev file,id=id,path=path[,input-path=input-file][,mux=on|off][,logfile=PATH][,logappend=on|off]\n" > - "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" > + "-chardev file,id=id,path=path[,input-path=input-file][,mux=on|off][,mux-be-id=id][,logfile=PATH][,logappend=on|off]\n" > + "-chardev pipe,id=id,path=path[,mux=on|off][,mux-be-id=id][,logfile=PATH][,logappend=on|off]\n" > #ifdef _WIN32 > - "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" > - "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" > + "-chardev console,id=id[,mux=on|off][,mux-be-id=id][,logfile=PATH][,logappend=on|off]\n" > + "-chardev serial,id=id,path=path[,mux=on|off][,mux-be-id=id][,logfile=PATH][,logappend=on|off]\n" > #else > - "-chardev pty,id=id[,path=path][,mux=on|off][,logfile=PATH][,logappend=on|off]\n" > - "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n" > + "-chardev pty,id=id[,path=path][,mux=on|off][,mux-be-id=id][,logfile=PATH][,logappend=on|off]\n" > + "-chardev stdio,id=id[,mux=on|off][,mux-be-id=id][,signal=on|off][,logfile=PATH][,logappend=on|off]\n" > #endif > #ifdef CONFIG_BRLAPI > - "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" > + "-chardev braille,id=id[,mux=on|off][,mux-be-id=id][,logfile=PATH][,logappend=on|off]\n" > #endif > #if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ > || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) > - "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" > + "-chardev serial,id=id,path=path[,mux=on|off][,mux-be-id=id][,logfile=PATH][,logappend=on|off]\n" > #endif > #if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__) > - "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" > + "-chardev parallel,id=id,path=path[,mux=on|off][,mux-be-id=id][,logfile=PATH][,logappend=on|off]\n" > #endif > #if defined(CONFIG_SPICE) > "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" > @@ -3719,8 +3719,8 @@ DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, > SRST > The general form of a character device option is: > > -``-chardev backend,id=id[,mux=on|off][,options]`` > - Backend is one of: ``null``, ``socket``, ``udp``, ``msmouse``, > +``-chardev backend,id=id[,mux=on|off][,mux-be-id=id][,options]`` > + Backend is one of: ``null``, ``socket``, ``udp``, ``msmouse``, ``mux-be``, > ``vc``, ``ringbuf``, ``file``, ``pipe``, ``console``, ``serial``, > ``pty``, ``stdio``, ``braille``, ``parallel``, > ``spicevmc``, ``spiceport``. The specific backend will determine the > @@ -3777,9 +3777,10 @@ The general form of a character device option is: > the QEMU monitor, and ``-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). > + If you need to multiplex in the opposite direction (where one QEMU > + interface receives input and output from multiple chardev devices), > + each character device needs ``mux-be-id=id`` option. Please refer > + to the paragraph below regarding chardev ``mux-be`` configuration. > > Every backend supports the ``logfile`` option, which supplies the > path to a file to record all data transmitted via the backend. The > @@ -3879,6 +3880,43 @@ The available backends are: > Forward QEMU's emulated msmouse events to the guest. ``msmouse`` > does not take any options. > > +``-chardev mux-be,id=id`` > + Explicitly create chardev backend multiplexer with possibility to > + multiplex in the opposite direction, where one QEMU interface > + (frontend device) receives input and output from multiple chardev > + backend devices. We are not very good at documenting the version, but you could add (Since 9.2) > + > + For example the following is a use case of 2 backend devices: text > + virtual console ``vc0`` and a socket ``sock0`` connected > + to a single virtio hvc console frontend device with multiplexer > + ``mux0`` help. Virtual console renders text to an image, which > + can be shared over the VNC protocol, in turn socket backend provides > + biderectional communication to the virtio hvc console over socket. bidirectional > + The example configuration can be the following: > + > + :: > + > + -chardev mux-be,id=mux0 \ > + -chardev socket,path=/tmp/sock,server=on,wait=off,id=sock0,mux-be-id=mux0 \ > + -chardev vc,id=vc0,mux-be-id=mux0 \ > + -device virtconsole,chardev=mux0 \ > + -vnc 0.0.0.0:0 > + > + Once QEMU starts VNC client and any TTY emulator can be used to > + control a single hvc console: > + > + :: > + > + # VNC client > + vncviewer :0 > + > + # TTY emulator > + socat unix-connect:/tmp/sock pty,link=/tmp/pty & \ > + tio /tmp/pty > + > + Multiplexing of several backend devices with serveral frontend devices several > + is not supported. > + > ``-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]`` > Connect to a QEMU text console. ``vc`` may optionally be given a > specific size. > -- > 2.34.1 >
diff --git a/qemu-options.hx b/qemu-options.hx index daae49414740..dd5dfe8596f0 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -3677,37 +3677,37 @@ DEFHEADING(Character device options:) DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, "-chardev help\n" - "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" + "-chardev null,id=id[,mux=on|off][,mux-be-id=id][,logfile=PATH][,logappend=on|off]\n" "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4=on|off][,ipv6=on|off][,nodelay=on|off]\n" - " [,server=on|off][,wait=on|off][,telnet=on|off][,websocket=on|off][,reconnect=seconds][,mux=on|off]\n" + " [,server=on|off][,wait=on|off][,telnet=on|off][,websocket=on|off][,reconnect=seconds][,mux=on|off][,mux-be-id=id]\n" " [,logfile=PATH][,logappend=on|off][,tls-creds=ID][,tls-authz=ID] (tcp)\n" "-chardev socket,id=id,path=path[,server=on|off][,wait=on|off][,telnet=on|off][,websocket=on|off][,reconnect=seconds]\n" - " [,mux=on|off][,logfile=PATH][,logappend=on|off][,abstract=on|off][,tight=on|off] (unix)\n" + " [,mux=on|off][,mux-be-id=id][,logfile=PATH][,logappend=on|off][,abstract=on|off][,tight=on|off] (unix)\n" "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n" - " [,localport=localport][,ipv4=on|off][,ipv6=on|off][,mux=on|off]\n" + " [,localport=localport][,ipv4=on|off][,ipv6=on|off][,mux=on|off][,mux-be-id=id]\n" " [,logfile=PATH][,logappend=on|off]\n" - "-chardev msmouse,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" + "-chardev msmouse,id=id[,mux=on|off][,mux-be-id=id][,logfile=PATH][,logappend=on|off]\n" "-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]\n" - " [,mux=on|off][,logfile=PATH][,logappend=on|off]\n" + " [,mux=on|off][,mux-be-id=id][,logfile=PATH][,logappend=on|off]\n" "-chardev ringbuf,id=id[,size=size][,logfile=PATH][,logappend=on|off]\n" - "-chardev file,id=id,path=path[,input-path=input-file][,mux=on|off][,logfile=PATH][,logappend=on|off]\n" - "-chardev pipe,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" + "-chardev file,id=id,path=path[,input-path=input-file][,mux=on|off][,mux-be-id=id][,logfile=PATH][,logappend=on|off]\n" + "-chardev pipe,id=id,path=path[,mux=on|off][,mux-be-id=id][,logfile=PATH][,logappend=on|off]\n" #ifdef _WIN32 - "-chardev console,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" - "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" + "-chardev console,id=id[,mux=on|off][,mux-be-id=id][,logfile=PATH][,logappend=on|off]\n" + "-chardev serial,id=id,path=path[,mux=on|off][,mux-be-id=id][,logfile=PATH][,logappend=on|off]\n" #else - "-chardev pty,id=id[,path=path][,mux=on|off][,logfile=PATH][,logappend=on|off]\n" - "-chardev stdio,id=id[,mux=on|off][,signal=on|off][,logfile=PATH][,logappend=on|off]\n" + "-chardev pty,id=id[,path=path][,mux=on|off][,mux-be-id=id][,logfile=PATH][,logappend=on|off]\n" + "-chardev stdio,id=id[,mux=on|off][,mux-be-id=id][,signal=on|off][,logfile=PATH][,logappend=on|off]\n" #endif #ifdef CONFIG_BRLAPI - "-chardev braille,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" + "-chardev braille,id=id[,mux=on|off][,mux-be-id=id][,logfile=PATH][,logappend=on|off]\n" #endif #if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) - "-chardev serial,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" + "-chardev serial,id=id,path=path[,mux=on|off][,mux-be-id=id][,logfile=PATH][,logappend=on|off]\n" #endif #if defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__) - "-chardev parallel,id=id,path=path[,mux=on|off][,logfile=PATH][,logappend=on|off]\n" + "-chardev parallel,id=id,path=path[,mux=on|off][,mux-be-id=id][,logfile=PATH][,logappend=on|off]\n" #endif #if defined(CONFIG_SPICE) "-chardev spicevmc,id=id,name=name[,debug=debug][,logfile=PATH][,logappend=on|off]\n" @@ -3719,8 +3719,8 @@ DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, SRST The general form of a character device option is: -``-chardev backend,id=id[,mux=on|off][,options]`` - Backend is one of: ``null``, ``socket``, ``udp``, ``msmouse``, +``-chardev backend,id=id[,mux=on|off][,mux-be-id=id][,options]`` + Backend is one of: ``null``, ``socket``, ``udp``, ``msmouse``, ``mux-be``, ``vc``, ``ringbuf``, ``file``, ``pipe``, ``console``, ``serial``, ``pty``, ``stdio``, ``braille``, ``parallel``, ``spicevmc``, ``spiceport``. The specific backend will determine the @@ -3777,9 +3777,10 @@ The general form of a character device option is: the QEMU monitor, and ``-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). + If you need to multiplex in the opposite direction (where one QEMU + interface receives input and output from multiple chardev devices), + each character device needs ``mux-be-id=id`` option. Please refer + to the paragraph below regarding chardev ``mux-be`` configuration. Every backend supports the ``logfile`` option, which supplies the path to a file to record all data transmitted via the backend. The @@ -3879,6 +3880,43 @@ The available backends are: Forward QEMU's emulated msmouse events to the guest. ``msmouse`` does not take any options. +``-chardev mux-be,id=id`` + Explicitly create chardev backend multiplexer with possibility to + multiplex in the opposite direction, where one QEMU interface + (frontend device) receives input and output from multiple chardev + backend devices. + + For example the following is a use case of 2 backend devices: text + virtual console ``vc0`` and a socket ``sock0`` connected + to a single virtio hvc console frontend device with multiplexer + ``mux0`` help. Virtual console renders text to an image, which + can be shared over the VNC protocol, in turn socket backend provides + biderectional communication to the virtio hvc console over socket. + The example configuration can be the following: + + :: + + -chardev mux-be,id=mux0 \ + -chardev socket,path=/tmp/sock,server=on,wait=off,id=sock0,mux-be-id=mux0 \ + -chardev vc,id=vc0,mux-be-id=mux0 \ + -device virtconsole,chardev=mux0 \ + -vnc 0.0.0.0:0 + + Once QEMU starts VNC client and any TTY emulator can be used to + control a single hvc console: + + :: + + # VNC client + vncviewer :0 + + # TTY emulator + socat unix-connect:/tmp/sock pty,link=/tmp/pty & \ + tio /tmp/pty + + Multiplexing of several backend devices with serveral frontend devices + is not supported. + ``-chardev vc,id=id[[,width=width][,height=height]][[,cols=cols][,rows=rows]]`` Connect to a QEMU text console. ``vc`` may optionally be given a specific size.
This adds a few lines describing `mux-be` multiplexer configuration for multiplexing several backend devices with a single frontend device. Signed-off-by: Roman Penyaev <r.peniaev@gmail.com> Cc: "Marc-André Lureau" <marcandre.lureau@redhat.com> Cc: qemu-devel@nongnu.org --- qemu-options.hx | 78 ++++++++++++++++++++++++++++++++++++------------- 1 file changed, 58 insertions(+), 20 deletions(-)