Mailing List Archive

X server connection refused, lspci hangs up the system & more issues
Hello there Xen users.

I recently installed Xen to try some virtualization experiments. I strictly
followed the beginners guide from Xen wiki. After installing, I rebooted
into Xen and quickly discovered that X server didn't start. When running
startx, it messaged me "Waiting for X server to start accepting
connections" and, after some time, "Connection refused". I had a similar
experience with sudo Xorg -configure - nothing was returned by the system
and no Xorg config file was created, it just hung up until I killed it
manually by sending SIGINT (^C) signal. X server didn't write anything
useful into /var/log/Xorg.0.log, there was an error (sddm authorization
file not found) but it exists in the normal, not Xen-powered system, too,
so I guess it's not the root cause here.

The more I tried to investigate the situation, the less I understood
anything. lspci -k worked on the non-Xen system succesfully, while inside
Xen dom0 it just hung everything up and the only solution was to shut down
my laptop with force. upower didn't show anything and exited with an error,
and shutdown, poweroff and reboot commands didn't work either - they exited
the shell, but when the system was still running until I pressed the power
button on my laptop. This issue is described in Xen wiki, in Dom0 faq, and
its explained that its possible to solve it with disabling ACPI in boot
settings; however, after I disabled ACPI, i just lost connection to the
keyboard and couldn't ever log in.

I also noticed that there is no network (dmesg says ipv6 link not ready),
and listing PCI devices in dom0 by xl pci-list didn't show anything. lsusb
showed everything right, though.

I found people with similar experience here and other IT communities, but
no one really could solve their problem. Some advices I tried was to
disable ACPI (by Xen wiki, didn't work), blacklist Nouveau drivers (didn't
work), recompile the GPU kernel module to work with Xen (I dunno how, there
is guides for NVIDIA, but for AMD Radeon, really nothing).

I guess Xen somehow blocked dom0 from accessing some hardware and I'll need
to rebuild some kernel modules to re-enable it. I haven't figured out the
correct solution yet; on Gentoo forums, some guys who had similar issues
rebuilt the kernel and some modules... and it worked, but then they
discovered something was working ugly. Or not. Some had their X crashing
and Firefox behaving extremely slow, some had not.

Thank you in advance,
Linux Debillian-Dev 4.19.0-11-amd64 #1 SMP Debian 4.19.146-1 (2020-09-17)
x86_64 GNU/Linux

Hardware info attached.