Re: AMD Ryzen 4000 (Mobile) cpufreq issues

[Jason Andryuk <jandryuk@xxxxxxxxx>]

On Mon, Mar 15, 2021 at 11:03 PM Dylanger Daly
<dylangerdaly@xxxxxxxxxxxxxx> wrote:
>
> Hi Xen Developers,
>
> It appears AMD Ryzen 4000 based CPUs are not supported by `xenpm`, running 
> `xenpm get-cpufreq-states` returns nothing and `get-cpufreq-para` returns 
> `failed to get cpufreq parameter`

In dom0, do `modprobe xen-acpi-processor`  and see if `xenpm
get-cpufreq-para` works.  Xen needs Dom0 to load some ACPI info before
xenpm can work.

Are you running Qubes?  For some reason xen-acpi-processor doesn't
load there automatically.

> This was somewhat expected as Ryzen 4000 series CPUs are quite new, so as a 
> workaround I tried putting `cpufreq=dom0-kernel dom0_max_vcpus=8 
> dom0_vcpus_pin` onto CMDLINE, from what I've read this should essentially 
> pass control for CPU frequency scaling down to dom0's kernel (5.11.4).
>
> However acpi-cpufreq doesn't load, when trying to insmod it I get the 
> following error `insmod: ERROR: could not insert module acpi-cpufreq.ko: No 
> such device`
>
> I can't seem to see anything related to Xen relinquishing control to dom0 in 
> Xen's console, any help would be appreciated

I haven't tried using cpufreq=dom0-kernel, so I can't help here.

Regards,
Jason