On 22.08.2025 12:52, Penny Zheng wrote:
> Even if Xen governor is not used in amd-cppc active mode, we could
> somehow deduce which performance policy (CPUFREQ_POLICY_xxx) user wants to
> apply through which governor they choose, such as:
> If user chooses performance governor, they want maximum performance, then
> the policy shall be CPUFREQ_POLICY_PERFORMANCE
> If user chooses powersave governor, they want the least power consumption,
> then the policy shall be CPUFREQ_POLICY_POWERSAVE
> Function cpufreq_policy_from_governor() is responsible for above transition,
> and it shall be also effective when users setting new governor through xenpm.
>
> userspace are forbidden choices, and if users specify such options,
Odd use of plural here, when only one bad variant is named.
> --- a/xen/drivers/acpi/pm-op.c
> +++ b/xen/drivers/acpi/pm-op.c
> @@ -206,6 +206,14 @@ static int set_cpufreq_gov(struct xen_sysctl_pm_op *op)
> if ( new_policy.governor == NULL )
> return -EINVAL;
>
> + new_policy.policy = cpufreq_policy_from_governor(new_policy.governor);
> + if ( new_policy.policy == CPUFREQ_POLICY_UNKNOWN )
> + {
> + printk("Failed to get performance policy from %s, Try \"xenpm
> set-cpufreq-cppc\"\n",
> + new_policy.governor->name);
> + return -EINVAL;
> + }
Don't you also need to check for CPPC mode, or else you reject "userspace" for
other drivers as well?
Jan
