[PPC] Remove extra \0 char inserted on vty by QEMU
ClosedPublic
Actions

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

Lint

Lint Passed

Unit

No Test Coverage

Build Status

Buildable 27766
Build 25956: arc lint + arc unit

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
315–338	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
315–338	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.