[PPC] Remove extra \0 char inserted on vty by QEMU
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Authored by luporl on Oct 28 2019, 12:50 PM.

Details

Reviewers

jhibbits
bdragon

Commits

rS355209: [PPC] Remove extra \0 char inserted on vty by QEMU

Summary

Since version 2.11.0, QEMU became bug-compatible with
PowerVM's vty implementation, by inserting a \0 after
every \r going to the guest. Guests are expected to
workaround this issue by removing every \0 immediately
following a \r.

Test Plan

How to reproduce the issue:

Start a FreeBSD VM with QEMU >= 2.11.0, appending -serial pty to its command line.
On the VM, run minicom -H -D /dev/cuauX
On the host, run minicom -H -D /dev/pts/Y
On the host, type something and hit ENTER

The minicom running on the VM will then show an extra 00 char after 0d.

Diff Detail

Repository

rS FreeBSD src repository - subversion

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Lint Not Applicable

Unit

Tests Not Applicable

Event Timeline

luporl created this revision.Oct 28 2019, 12:50 PM

Harbormaster completed remote builds in B27242: Diff 63727.Oct 28 2019, 12:50 PM

jhibbits added inline comments.Nov 2 2019, 9:00 PM

sys/powerpc/pseries/phyp_console.c
315 ↗	(On Diff #63727)	Since you're already reading one character at a time, why not copy as you read, instead of the sequence of memmove() operations?

luporl edited the test plan for this revision. (Show Details)Nov 25 2019, 7:37 PM

Merge branch 'master' into luporl-fix-vty
Address review comments

Harbormaster completed remote builds in B27766: Diff 64865.Nov 25 2019, 7:42 PM

luporl marked an inline comment as done.Nov 25 2019, 7:50 PM

luporl added inline comments.

sys/powerpc/pseries/phyp_console.c
315 ↗	(On Diff #63727)	Ok, done, it looks better now. I've also added the `if (hdr == 1)` condition, because the removal of \0's should only be done once per hypervisor read, to avoid removing valid \0's after \r's, when phyp_inbuf is consumed by small reads.