(Re-CC'ing the ML because I forgot by accident. Hopefully the quoted sections provide sufficient context)
On Tuesday, December 30th, 2025 at 10:44 AM, Jason Andryuk <[email protected]> wrote: > > > On Mon, Dec 29, 2025 at 6:59 PM Milky [email protected] wrote: > > I've tried the command you suggested. Like `xenpm get-cpufreq-states`, it > > returns no output. I am pasting it below anyway, for completeness. > > > > ``` > > [root@dom0 username] xenpm get-cpufreq-average > > <no output> > > ``` > > > > For the record, I tracked the original > > [thread](https://lists.xen.org/archives/html/xen-devel/2024-01/msg00787.html) > > where you posted that suggestion. [...] > > > HWP enabled > > > > Indeed I noticed that in the `xl dmesg` logs too, which seemed reassuring, > > however I didn't want to jump to conclusions and the "HW_FEEDBACK not > > supported" line raised some concerns (although I was unable to find out > > what it means). > > > HW_FEEDBACK support doesn't matter. [...] > > > > The following commands were also checked: > > > > > > > > ``` > > > > $ xenpm get-cpufreq-para > > > > [CPU0] failed to get cpufreq parameter > > > We want this to work to get info on how HWP is configured. It could > be set to a power save mode, and xenpm set-cpufreq-para would let you > set it to be more performant. It's bizarre that it is not working. [...] > You need xen-acpi-processor to upload ACPI CPU data to Xen. That lets > Xen know how to run cpufreq for the CPUs. cpufreq will not be enabled > without the ACPI CPU data upload. If you add to dom0's command line: > loglevel=9 dyndbg="module xen_acpi_processor +p" > xen_acpi_processor.dyndbg="func * +p" > > You'll hopefully enable the dynamic debugging. > > And do: > sudo dmesg | grep xen.acpi > maybe you'd get some info? > > Or `modprobe xen-acpi-processor dyndbg==pmf` > > You want to see messages like: > ACPI CPU%u - P-states uploaded > https://elixir.bootlin.com/linux/v6.18.2/source/drivers/xen/xen-acpi-processor.c#L248 > > If you see this one: > pr_warn("ACPI CPU%u missing some P-state data (%x), skipping\n", > _pr->acpi_id, dst_perf->flags); > > Then that may be why it's not working. As suggested, I added the debug parameters to the dom0 kernel. Before or after `modprobe xen-acpi-processor dyndbg==pmf`, there is no useful debug information that I could find, apart from the `xen_acpi_processor:get_max_acpi_id` message as seen below. ``` # sudo dmesg | grep xen.acpi [ 2.282851] Kernel command line: placeholder root=/dev/mapper/qubes_dom0-root ro rd.luks.uuid=<...> rd.lvm.lv=qubes_dom0/root rd.lvm.lv=qubes_dom0/swap plymouth.ignore-serial-consoles 6.6.77-1.qubes.fc37.x86_64 x86_64 rhgb loglevel=9 "dyndbg=module xen_acpi_processor +p" "xen_acpi_processor.dyndbg=func * +p" rd.qubes.hide_all_usb [ 5.224092] xen_acpi_processor: Max ACPI ID: 6 # sudo lsmod | grep xen_acpi <no output> # sudo modprobe xen-acpi-processor dyndbg==pmf modprobe: ERROR: could not insert 'xen_acpi_processor': No such device ``` > You flashed the T480s with Coreboot? Maybe the Coreboot ACPI data > lacks something? I flased it with Coreboot, yes; more specifically, I executed manually the build steps of Libreboot. It's possible I've made a mistake somewhere. However, as I mentioned in my first message, scaling actually works correctly when booting with vanilla Debian. > Maybe also with Xen's command line try cpufreq=xen:no-hwp to disable > HWP and see if the regular ACPI cpufreq driver works better. > > I'm thinking it's something where xen-acpi-processor didn't upload > ACPI CPU data, which means cpufreq isn't running. That may also be > why you see that bogus CPU frequency. After booting with `xen:no-hwp`, I wasn't sure how to check if the regular ACPI cpufreq driver is operational. Is `xenpm` still the correct way to query for CPU info? I've tried the following: ``` # sudo xl dmesg | grep -i hwp (XEN) Command line: placeholder cpufreq=xen:no-hwp,verbose loglvl=all dom0_mem=min:1024M dom0_mem=max:4096M ucode=scan smt=off gnttab_max_frames=2048 gnttab_max_maptrack_frames=4096 no-real-mode edd=off (XEN) HWP: 1 notify: 1 act-window: 1 energy-perf: 1 pkg-level: 0 peci: 0 (XEN) HWP: Hardware Duty Cycling (HDC) supported, enabled (XEN) HWP: HW_FEEDBACK not supported # sudo xenpm get-cpufreq-para [CPU0] failed to get cpufreq parameter [CPU1] failed to get cpufreq parameter [CPU2] failed to get cpufreq parameter [CPU3] failed to get cpufreq parameter # sudo xenpm get-cpufreq-average <no output> # sudo xenpm start 10 | grep 'Avg freq' Avg freq 884114144 KHz Avg freq 884114144 KHz Avg freq 884114144 KHz Avg freq 884114144 KHz ```
