[PATCH v3 08/10] x86/resctrl: Add the sysfs interface to read the event configuration

[Babu Moger]

The current event configuration can be viewed by the user by reading
the sysfs configuration file.

Following are the types of events supported.
====================================================================
Bits    Description
6       Dirty Victims from the QOS domain to all types of memory
5       Reads to slow memory in the non-local NUMA domain
4       Reads to slow memory in the local NUMA domain
3       Non-temporal writes to non-local NUMA domain
2       Non-temporal writes to local NUMA domain
1       Reads to memory in the non-local NUMA domain
0       Reads to memory in the local NUMA domain

By default the mbm_total_bytes configuration is set to 0x7f to count
all the types of events and mbm_local_bytes configuration is set to
0x15 to count all the local memory events.

$cat /sys/fs/resctrl/mon_data/mon_L3_00/mbm_total_config
0x7f

$cat /sys/fs/resctrl/mon_data/mon_L3_00/mbm_local_config
0x15

Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
Reviewed-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 arch/x86/kernel/cpu/resctrl/internal.h |   21 ++++++++++
 arch/x86/kernel/cpu/resctrl/rdtgroup.c |   70 ++++++++++++++++++++++++++++++++
 2 files changed, 91 insertions(+)

diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index fc725f5e9024..457666709386 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -15,6 +15,7 @@
 #define MSR_IA32_MBA_THRTL_BASE		0xd50
 #define MSR_IA32_MBA_BW_BASE		0xc0000200
 #define MSR_IA32_SMBA_BW_BASE		0xc0000280
+#define MSR_IA32_EVT_CFG_BASE		0xc0000400
 
 #define MSR_IA32_QM_CTR			0x0c8e
 #define MSR_IA32_QM_EVTSEL		0x0c8d
@@ -50,6 +51,26 @@
  */
 #define MBM_CNTR_WIDTH_OFFSET_MAX (62 - MBM_CNTR_WIDTH_BASE)
 
+/* Reads to Local DRAM Memory */
+#define READS_TO_LOCAL_MEM		BIT(0)
+
+/* Reads to Remote DRAM Memory */
+#define READS_TO_REMOTE_MEM		BIT(1)
+
+/* Non-Temporal Writes to Local Memory */
+#define NON_TEMP_WRITE_TO_LOCAL_MEM	BIT(2)
+
+/* Non-Temporal Writes to Remote Memory */
+#define NON_TEMP_WRITE_TO_REMOTE_MEM	BIT(3)
+
+/* Reads to Local Memory the system identifies as "Slow Memory" */
+#define READS_TO_LOCAL_S_MEM		BIT(4)
+
+/* Reads to Remote Memory the system identifies as "Slow Memory" */
+#define READS_TO_REMOTE_S_MEM		BIT(5)
+
+/* Dirty Victims to All Types of Memory */
+#define  DIRTY_VICTIS_TO_ALL_MEM	BIT(6)
 
 struct rdt_fs_context {
 	struct kernfs_fs_context	kfc;
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 30d2182d4fda..e1847d49fa15 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -254,8 +254,78 @@ static const struct kernfs_ops kf_mondata_ops = {
 	.seq_show		= rdtgroup_mondata_show,
 };
 
+/*
+ * This is called via IPI to read the CQM/MBM counters
+ * in a domain.
+ */
+void mon_event_config_read(void *info)
+{
+	union mon_data_bits *md = info;
+	u32 evtid = md->u.evtid;
+	u32 h, msr_index;
+
+	switch (evtid) {
+	case QOS_L3_MBM_TOTAL_EVENT_ID:
+		msr_index = 0;
+		break;
+	case QOS_L3_MBM_LOCAL_EVENT_ID:
+		msr_index = 1;
+		break;
+	default:
+		return; /* Not expected to come here */
+	}
+
+	rdmsr(MSR_IA32_EVT_CFG_BASE + msr_index, md->u.mon_config, h);
+}
+
+void mondata_config_read(struct rdt_domain *d, union mon_data_bits *md)
+{
+	smp_call_function_any(&d->cpu_mask, mon_event_config_read, md, 1);
+}
+
+int rdtgroup_mondata_config_show(struct seq_file *m, void *arg)
+{
+	struct kernfs_open_file *of = m->private;
+	struct rdt_hw_resource *hw_res;
+	u32 resid, evtid, domid;
+	struct rdtgroup *rdtgrp;
+	struct rdt_resource *r;
+	union mon_data_bits md;
+	struct rdt_domain *d;
+	int ret = 0;
+
+	rdtgrp = rdtgroup_kn_lock_live(of->kn);
+	if (!rdtgrp) {
+		ret = -ENOENT;
+		goto out;
+	}
+
+	md.priv = of->kn->priv;
+	resid = md.u.rid;
+	domid = md.u.domid;
+	evtid = md.u.evtid;
+
+	hw_res = &rdt_resources_all[resid];
+	r = &hw_res->r_resctrl;
+
+	d = rdt_find_domain(r, domid, NULL);
+	if (IS_ERR_OR_NULL(d)) {
+		ret = -ENOENT;
+		goto out;
+	}
+
+	mondata_config_read(d, &md);
+
+	seq_printf(m, "0x%x\n", md.u.mon_config);
+
+out:
+	rdtgroup_kn_unlock(of->kn);
+	return ret;
+}
+
 static const struct kernfs_ops kf_mondata_config_ops = {
 	.atomic_write_len       = PAGE_SIZE,
+	.seq_show               = rdtgroup_mondata_config_show,
 };
 
 static bool is_cpu_list(struct kernfs_open_file *of)