[Pkg-xen-devel] [PATCH 7/9] debian/xen.init: Load xen_acpi_processor on boot

[Elliott Mitchell]

On Tue, Dec 15, 2020 at 12:18:15PM +0100, Hans van Kranenburg wrote:
> I'm testing this change, but it seems I can't get past the "modprobe:
> ERROR: could not insert 'xen_acpi_processor': No such device" error on
> any hardware I have to test with. (with linux-image-5.9.0-4-amd64
> version 5.9.11-1 as dom0 kernel).

According to appropriate documentation, ENODEV comes from the module
itself and not the standard loading process.  In
linux-5.9/drivers/xen/xen-acpi-processor.c there are 3 occurrences of
ENODEV, so it would be one of those.  One of those has a pr_warn(), so it
would directly show up in `dmesg`.  The other two don't look as likely to
trigger and I'm unsure what messages they would produce.

My main Xen machine is presently on Xen 4.11 and kernel 4.19.  

Seems the comment above read_acpi_id() has been broken.  :-(  Right now
if Dom0 has fewer vCPUs than the machine has actual processors, the
C-states don't get setup for the processors which lack vCPUs.  Workaround
I've got right now is hot unplugging some processors after boot.


-- 
(\___(\___(\______          --=> 8-) EHM <=--          ______/)___/)___/)
 \BS (    |         ehem+sigmsg at m5p.com  PGP 87145445         |    )   /
  \_CS\   |  _____  -O #include <stddisclaimer.h> O-   _____  |   /  _/
8A19\___\_|_/58D2 7E3D DDF4 7BA6 <-PGP-> 41D1 B375 37D0 8714\_|_/___/5445