On 17/12/2015 12:55, Daniel P. Berrange wrote: > Typically a UNIX guest OS will log boot messages to a serial > port in addition to any graphical console. An admin user > may also wish to use the serial port for an interactive > console. A virtualization management system may wish to > collect system boot messages by logging the serial port, > but also wish to allow admins interactive access. > > Currently providing such a feature forces the mgmt app > to either provide 2 separate serial ports, one for > logging boot messages and one for interactive console > login, or to proxy all output via a separate service > that can multiplex the two needs onto one serial port. > While both are valid approaches, they each have their > own downsides. The former causes confusion and extra > setup work for VM admins creating disk images. The latter > places an extra burden to re-implement much of the QEMU > chardev backends logic in libvirt or even higher level > mgmt apps and adds extra hops in the data transfer path. > > A simpler approach that is satisfactory for many use > cases is to allow the QEMU chardev backends to have a > "logfile" property associated with them. > > $QEMU -chardev socket,host=localhost,port=9000,\ > server=on,nowait,id-charserial0,\ > logfile=/var/log/libvirt/qemu/test-serial0.log > -device isa-serial,chardev=charserial0,id=serial0
Why for socket only? It would be very useful for stdio and especially vc. Paolo
