serial hang in qemu-system-ppc64 -M pseries

[Thomas Huth]

On 26/04/2022 12.26, Rob Landley wrote:
> When I cut and paste 80-ish characters of text into the Linux serial console, it
> reads 16 characters and stops. When I hit space, it reads another 16 characters,
> and if I keep at it will eventually catch up without losing data. If I type,
> every character shows up immediately.

That "16" certainly comes from VTERM_BUFSIZE in hw/char/spapr_vty.c in the 
QEMU sources, I think.

> (On other qemu targets and kernels I can cut and paste an entire uuencoded
> binary and it goes through just fine in one go, but this target hangs with big
> pastes until I hit keys.)
> 
> Is this a qemu-side bug, or a kernel-side bug?
> 
> Kernel config attached (linux 5.18-rc3 or thereabouts), qemu invocation is:
> 
> qemu-system-ppc64 -M pseries -vga none -nographic -no-reboot -m 256 -kernel
> vmlinux -initrd powerpc64leroot.cpio.gz -append "panic=1 HOST=powerpc64le
> console=hvc0"

Which version of QEMU are you using? Which frontend (GTK or terminal?) ... 
this rings a distant bell, but I thought we had fixed these issues long ago 
in the past... e.g.:

https://yhbt.net/lore/all/1380113886-16845-10-git-send-email-mdroth@linux.vnet.ibm.com/

https://git.qemu.org/?p=qemu.git;a=commitdiff;h=8a273cbe53221d28

... but maybe my memory also just fails and this has never been properly fixed.

  Thomas