On 8/25/2021 4:16 PM, Phillip Susi wrote:
Chuck Zmudzinski <brchuckz@netscape.net> writes:If it doesn't work, I am also willing to try approach a by patching the Linux kernel xen-kbdfront driver by removing the for loops that advertise those 654 keys. I tend to agree with Philip that this is totally unnecessary, but I suppose I could be wrong about that. I read the discussion Philip had with the Xen developers and they seemed to want to keep the Xen keyboard driver as it is.That was the first thing I tried and the libinput maintainer pointed out that if you don't advertise the keys, you can't use the keys. In other words, somebody presses that key on their keyboard and the domU won't recognize it.
Well, good news - It looks like Ben's patch works, I just tested it in my full
install in a Xen HVM domU and all looks good. I did not see the Coldplug failure at the beginning of the boot - it is hard to miss in the bright red letters on the console, and even more convincing is the fact that another symptom of the bug is gone. This bug manifests itself in udev not being able to write uevent data to sysfs for the Xen Virtual Keyboard. With Ben's patch of increasing the UEVENT_BUFFER_SIZE from 2048 to 4096, udev can write its uevent data to sysfs for the Xen Virtual Keyboard: With the current 5.10.0-8 kernel: chuckz@debian:~$ cat /sys/devices/virtual/input/input2/uevent chuckz@debian:~$ With the patched kernel with a change to the ABI version from 8 to 8.1: chuckz@debian:~$ uname -r 5.10.0-8.1-amd64 chuckz@debian:~$ cat /sys/devices/virtual/input/input2/uevent PRODUCT=1/5853/ffff/0 NAME="Xen Virtual Keyboard" PHYS="xenbus/device/vkbd/0" PROP=0 EV=3 KEY=7fffffffffffffff ffffffffffffffff ffffffffffffffff... MODALIAS=input:b0001v5853pFFFFe0000-e0,1,k71,72... really long MODALIAS I expect with that patch the installation media will work in a Xen HVM domU. Cheers, Chuck