boot: 0.800
device: 0.768
graphic: 0.766
semantic: 0.752
instruction: 0.728
network: 0.708
vnc: 0.698
assembly: 0.677
other: 0.620
socket: 0.534
KVM: 0.469
mistranslation: 0.380

"-serial telnet::xxxx,server" causes "Device 'serial0' is in use"

I start qemu version 4.2.50 in a first terminal :

$ sudo ./qemu-system-hppa -boot d -serial telnet::4441,server -drive if=scsi,bus=0,index=6,file=./hpux.img,format=raw -serial mon:stdio -D /tmp/foo -nographic -m 512 -d nochain -cdrom ./HPUX_9.05_Installation_Disc_S700.iso -D /tmp/foo -net nic,model=tulip  -net tap

qemu-system-hppa: -serial telnet::4441,server: info: QEMU waiting for connection on: disconnected:telnet:0.0.0.0:4441,server

In another terminal, I launch "telnet localhost 4441"

And in the qemu window I have the following error:

Unexpected error in qemu_chr_fe_init() at chardev/char-fe.c:220:
qemu-system-hppa: Device 'serial0' is in use

Try top put "-serial mon:stdio" before "-serial telnet::4441,server"


Effectively, no more error !
Now, my hppa machine is booted on its installation support for HP-UX 10.20, et I am connected with telnet in an other terminal. I don't know what I must enter now (on a real machine, the installation starts automatically, if I remember well what I did in 1990 !)

If I use an installation support HP-UX 11.00, the installation starts automatically. Then, it finds no disk for installation, but I will work on the drive option of qemu to resolve this trouble.
Thanks a lot for your help !

I would observe that it would be much better if the order of the -serial arguments did not matter so much.  I know gcc has the same sort of madness (for instance), but it sure isn't intuitive.

But in my case, when you do the -serial things out of order, you end up with a segfault.
That can't be the intended behavior.

Yes, a segfault is definitely a bug. Can you give instructions to reproduce that (full command line, any necessary images) ? The example originally reported in this bug doesn't seem to be a segfault.

I'm now using qemu-system-hppa version 5.2.50, and I can put "-serial mon: stdio" before or after "-serial telnet :: 4441, server" without a problem.

#qemu-system-hppa --version
QEMU emulator version 5.2.50 (v5.2.0-1300-g0e32462630)
Copyright (c) 2003-2020 Fabrice Bellard and the QEMU Project developers

For me, no more bug.

Ok, since you said that there is no more bug, I'm closing this issue now.

Reporting again. Compiled QEMU from the latest stable Git:

QEMU emulator version 6.2.50 (v6.2.0-529-gfb084237a3)
Copyright (c) 2003-2021 Fabrice Bellard and the QEMU Project developers

Exactly as original post, if I place -serial telnet::4441,server ahead of -serial mon,stdio on the command line, it dumps core and aborts.

if I flip them, it runs... BUT! The vm console output appears in the terminal where I launched qemu, I get no output in the telnet session. That's backwards. I have no access to the qemu console and can't issue commands to do things like change the CDROM.

full command startup script (this one works but output doesn't happen where I expect)

#!/bin/sh
CDROM="-cdrom HP-UX-OE-1.iso"
QEMU=/home/ascott/Documents/hpux/qemu/qemu/build/qemu-system-hppa
IMAGE=/home/ascott/Documents/hpux/hpux.img
$QEMU -boot d -serial mon:stdio -serial telnet::4441,server -drive if=scsi,bus=0,index=6,file=$IMAGE,format=raw -nographic -m 512 -d nochain $CDROM  -net nic,model=tulip  -net user

This one dumps core with the serial0 error from the originla post:

#!/bin/sh
CDROM="-cdrom HP-UX-OE-1.iso"
QEMU=/home/ascott/Documents/hpux/qemu/qemu/build/qemu-system-hppa
IMAGE=/home/ascott/Documents/hpux/hpux.img
$QEMU -boot d -serial telnet::4441,server -serial mon:stdio -drive if=scsi,bus=0,index=6,file=$IMAGE,format=raw -nographic -m 512 -d nochain $CDROM  -net nic,model=tulip  -net user

ascott@vmhost01:~/Documents/hpux$ sh ./install-hpux.sh 
qemu-system-hppa: -serial telnet::4441,server: info: QEMU waiting for connection on: disconnected:telnet:0.0.0.0:4441,server=on
Unexpected error in qemu_chr_fe_init() at ../chardev/char-fe.c:220:
qemu-system-hppa: Device 'serial0' is in use
Aborted (core dumped)








Hi Andrew! The QEMU project does not use this bug tracker anymore - could you please open a new issue here: https://gitlab.com/qemu-project/qemu/-/issues - Thanks!