Re: "Force HWP min perf before offline" triggers unchecked MSR access errors

[Srinivas Pandruvada]

On Tue, 2019-10-29 at 18:01 -0400, Qian Cai wrote:
> > On Oct 29, 2019, at 5:47 PM, Rafael J. Wysocki <rafael@xxxxxxxxxx>
> > wrote:
> > 
> > The MSR_IA32_ENERGY_PERF_BIAS MSR appears to be not present, which
> > should be caught by the X86_FEATURE_EPB check in
> > intel_pstate_set_epb().
> > 
> > Do you run this in a guest perchance?
> 
> No, it is a baremetal HPE server. The dmesg does say something like
> energy perf bias changed from performance to normal, and the cpuflag
> contains epb which I thought that would pass the feature check? I
> could upload the whole dmesg a bit later if that helps.

Try the attached change. You have a Skylake server with no EPP support.
This is odd.

Thanks,
Srinivas

diff --git a/drivers/acpi/processor_thermal.c b/drivers/acpi/processor_thermal.c
index ec2638f1df4f..f70f746ed58d 100644
--- a/drivers/acpi/processor_thermal.c
+++ b/drivers/acpi/processor_thermal.c
@@ -130,6 +130,7 @@ void acpi_thermal_cpufreq_init(int cpu)
 	struct acpi_processor *pr = per_cpu(processors, cpu);
 	int ret;
 
+	memset(&pr->thermal_req, 0, sizeof(pr->thermal_req));
 	ret = dev_pm_qos_add_request(get_cpu_device(cpu),
 				     &pr->thermal_req, DEV_PM_QOS_MAX_FREQUENCY,
 				     INT_MAX);
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 9f02de9a1b47..eab8b048dc9f 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -851,7 +851,7 @@ static void intel_pstate_hwp_force_min_perf(int cpu)
 	if (boot_cpu_has(X86_FEATURE_HWP_EPP))
 		value |= HWP_ENERGY_PERF_PREFERENCE(HWP_EPP_POWERSAVE);
 	else
-		intel_pstate_set_epb(cpu, HWP_EPP_BALANCE_POWERSAVE);
+		intel_pstate_set_epb(cpu, 0x0F);
 
 	wrmsrl_on_cpu(cpu, MSR_HWP_REQUEST, value);
 }