x86/resctrl: Support monitor configuration

Add a new field in struct mon_evt to support Bandwidth Monitoring Event
Configuration (BMEC) and also update the "mon_features" display.

The resctrl file "mon_features" will display the supported events
and files that can be used to configure those events if monitor
configuration is supported.

Before the change:

  $ cat /sys/fs/resctrl/info/L3_MON/mon_features
  llc_occupancy
  mbm_total_bytes
  mbm_local_bytes

After the change when BMEC is supported:

  $ cat /sys/fs/resctrl/info/L3_MON/mon_features
  llc_occupancy
  mbm_total_bytes
  mbm_total_bytes_config
  mbm_local_bytes
  mbm_local_bytes_config

Signed-off-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lore.kernel.org/r/20230113152039.770054-9-babu.moger@amd.com

diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index f16b8bc..0605b04 100644 (file)
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -52,11 +52,13 @@ DECLARE_STATIC_KEY_FALSE(rdt_mon_enable_key);
  * struct mon_evt - Entry in the event list of a resource
  * @evtid:             event id
  * @name:              name of the event
+ * @configurable:      true if the event is configurable
  * @list:              entry in &rdt_resource->evt_list
  */
 struct mon_evt {
        enum resctrl_event_id   evtid;
        char                    *name;
+       bool                    configurable;
        struct list_head        list;
 };
 

diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
index 5665ab9..cf7b6e5 100644 (file)
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -800,6 +800,13 @@ int __init rdt_get_mon_l3_config(struct rdt_resource *r)
        if (ret)
                return ret;
 
+       if (rdt_cpu_has(X86_FEATURE_BMEC)) {
+               if (rdt_cpu_has(X86_FEATURE_CQM_MBM_TOTAL))
+                       mbm_total_event.configurable = true;
+               if (rdt_cpu_has(X86_FEATURE_CQM_MBM_LOCAL))
+                       mbm_local_event.configurable = true;
+       }
+
        l3_mon_evt_init(r);
 
        r->mon_capable = true;

diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 7516968..bf0bd43 100644 (file)
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -998,8 +998,11 @@ static int rdt_mon_features_show(struct kernfs_open_file *of,
        struct rdt_resource *r = of->kn->parent->priv;
        struct mon_evt *mevt;
 
-       list_for_each_entry(mevt, &r->evt_list, list)
+       list_for_each_entry(mevt, &r->evt_list, list) {
                seq_printf(seq, "%s\n", mevt->name);
+               if (mevt->configurable)
+                       seq_printf(seq, "%s_config\n", mevt->name);
+       }
 
        return 0;
 }