On 24.07.2023 14:58, Jason Andryuk wrote: > Add SET_CPUFREQ_HWP xen_sysctl_pm_op to set HWP parameters. The sysctl > supports setting multiple values simultaneously as indicated by the > set_params bits. This allows atomically applying new HWP configuration > via a single wrmsr. > > XEN_SYSCTL_HWP_SET_PRESET_BALANCE/PERFORMANCE/POWERSAVE provide three > common presets. Setting them depends on hardware limits which the > hypervisor is already caching. So using them allows skipping a > hypercall to query the limits (lowest/highest) to then set those same > values. The code is organized to allow a preset to be refined with > additional parameters if desired. > > "most_efficient" and "guaranteed" could be additional presets in the > future, but the are not added now. Those levels can change at runtime, > but we don't have code in place to monitor and update for those events. > > Since activity window may not be supported by all hardware, omit writing > it when not supported, and return that fact to userspace by updating > set_params. > > CPPC parameter checking disallows setting reserved bytes and ensure > values are only non-zero when the corresponding set_params bit is set. > There is no range checking (0-255 is allowed) since hardware is > documented to clip internally. > > Signed-off-by: Jason Andryuk <[email protected]>
Reviewed-by: Jan Beulich <[email protected]> with one last nit taken care of: > @@ -539,6 +543,103 @@ int get_hwp_para(unsigned int cpu, > return 0; > } > > +int set_hwp_para(struct cpufreq_policy *policy, > + struct xen_set_cppc_para *set_cppc) > +{ > + unsigned int cpu = policy->cpu; > + struct hwp_drv_data *data = per_cpu(hwp_drv_data, cpu); > + bool cleared_act_window = false; > + > + if ( data == NULL ) > + return -ENOENT; > + > + /* Validate all parameters - Disallow reserved bits. */ > + if ( set_cppc->minimum > 255 || > + set_cppc->maximum > 255 || > + set_cppc->desired > 255 || > + set_cppc->energy_perf > 255 || > + (set_cppc->set_params & ~XEN_SYSCTL_CPPC_SET_PARAM_MASK) || > + (set_cppc->activity_window & ~XEN_SYSCTL_CPPC_ACT_WINDOW_MASK) ) > + return -EINVAL; > + > + /* Only allow values if params bit is set. */ > + if ( (!(set_cppc->set_params & XEN_SYSCTL_CPPC_SET_DESIRED) && > + set_cppc->desired) || > + (!(set_cppc->set_params & XEN_SYSCTL_CPPC_SET_MINIMUM) && > + set_cppc->minimum) || > + (!(set_cppc->set_params & XEN_SYSCTL_CPPC_SET_MAXIMUM) && > + set_cppc->maximum) || > + (!(set_cppc->set_params & XEN_SYSCTL_CPPC_SET_ENERGY_PERF) && > + set_cppc->energy_perf) || > + (!(set_cppc->set_params & XEN_SYSCTL_CPPC_SET_ACT_WINDOW) && > + set_cppc->activity_window) ) > + return -EINVAL; > + > + /* Clear out activity window if lacking HW supported. */ > + if ( (set_cppc->set_params & XEN_SYSCTL_CPPC_SET_ACT_WINDOW) && > + !feature_hwp_activity_window ) { Yet another misplaced brace. Jan
