hi Peter, thank you for these explanations which answer perfectly to my need (which is only occasional).
regards, lacsaP. Le mar. 31 mars 2020 à 17:22, Peter Maydell <peter.mayd...@linaro.org> a écrit : > On Tue, 31 Mar 2020 at 15:45, Pascal <patate...@gmail.com> wrote: > > my goal is to be able to easily pass commands to qemu from my terminal > without the risk of terminating/killing qemu with an unfortunate Ctrl-C and > also to be able to push groups of commands there via a script . > > If you want to be able to script sending commands to > the QEMU monitor I think you'll find that's most easily > done by sending the monitor output somewhere else > (eg to a TCP socket), so it's not tangled up with > the guest terminal output. You can do that with > something like: > -chardev socket,id=monitor,host=127.0.0.1,port=4444,server,nowait,telnet > \ > -mon chardev=monitor,mode=readline > > which will make QEMU open a listening socket on port 4444. > You can then 'telnet localhost 4444' to connect to it. > For scripting I like 'expect'; here's an example expect > script which will connect to a running QEMU with a monitor > on port 4444, tell it to 'continue' (in this case I'd > started QEMU with '-S' to make it not boot the guest until > told to continue), wait briefly, do a 'savevm' and then > shut down QEMU: > > ===begin=== > #!/usr/bin/expect -f > > set timeout -1 > spawn telnet localhost 4444 > expect "(qemu)" > send "c\r" > sleep 0.2 > send "savevm foo\r" > expect "(qemu)" > send "quit\r" > expect eof > ===endit=== > > There's no problem with having multiple monitor connections, > so you can use those options together with '-serial mon:stdio' > which gives you both the telnet 4444 connection for the > scripting, plus the usual 'C-a c' to get at a second monitor > prompt for whatever manual stuff you want to do (and > avoids having 'C-c' kill QEMU). > > PS: scripting via what we call the "human monitor protocol" > is fine for small stuff, but if you plan to do more heavyweight > remote control of QEMU you probably want to investigate the > "QEMU Machine Protocol (QMP)", which is a JSON-based protocol. > You get basically the same functionality but in a more easily > machine-parsed format, and we give API stability guarantees > for QMP which we don't give for HMP. > https://wiki.qemu.org/Documentation/QMP > https://www.qemu.org/docs/master/qemu-qmp-ref.html > > thanks > -- PMM >
