[PATCH v4 10/13] x86/resctrl: Add the sysfs interface to read the event configuration

Babu Moger
2022-09-07T18:02:25Z

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 event types and the 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@amd.com>
---
arch/x86/kernel/cpu/resctrl/internal.h | 24 ++++++++++
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 77 ++++++++++++++++++++++++++++++++
2 files changed, 101 insertions(+)

diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index 45923eb4022f..96f439324d78 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 +51,29 @@
*/
#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_VICTIMS_TO_ALL_MEM BIT(6)
+
+/* Max event bits supported */
+#define MAX_EVT_CONFIG_BITS GENMASK(6, 0)

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 da11fdad204d..6f067c1ac7c1 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -254,8 +254,85 @@ static const struct kernfs_ops kf_mondata_ops = {
.seq_show = rdtgroup_mondata_show,
};

+struct mon_config_info {
+ u32 evtid;
+ u32 mon_config;
+};
+
+/*
+ * This is called via IPI to read the CQM/MBM counters
+ * in a domain.
+ */
+void mon_event_config_read(void *info)
+{
+ struct mon_config_info *mon_info = info;
+ u32 h, msr_index;
+
+ switch (mon_info->evtid) {
+ case QOS_L3_MBM_TOTAL_EVENT_ID:
+ msr_index = 0;
+ break;
+ case QOS_L3_MBM_LOCAL_EVENT_ID:
+ msr_index = 1;
+ break;
+ default:
+ /* Not expected to come here */
+ return;
+ }
+
+ rdmsr(MSR_IA32_EVT_CFG_BASE + msr_index, mon_info->mon_config, h);
+}
+
+void mondata_config_read(struct rdt_domain *d, struct mon_config_info *mon_info)
+{
+ smp_call_function_any(&d->cpu_mask, mon_event_config_read, mon_info, 1);
+}
+
+int rdtgroup_mondata_config_show(struct seq_file *m, void *arg)
+{
+ struct kernfs_open_file *of = m->private;
+ struct mon_config_info mon_info;
+ 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;
+ }
+
+ mon_info.evtid = evtid;
+ mondata_config_read(d, &mon_info);
+
+ seq_printf(m, "0x%x\n", mon_info.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)