[PATCH v4 18/19] x86/resctrl: Introduce interface to list monitor states of all the groups

Babu Moger
2024-05-24T12:26:20Z

Introduce the interface to list the monitor states of all the resctrl groups.

Example:
$cat /sys/fs/resctrl/info/L3_MON/mbm_assign_control

List follows the following format:

"<CTRL_MON group>/<MON group>/<domain_id>=<assignment_flags>"

Format for specific type of groups:

- Default CTRL_MON group:
"//<domain_id>=<assignment_flags>"

- Non-default CTRL_MON group:
"<CTRL_MON group>//<domain_id>=<assignment_flags>"

- Child MON group of default CTRL_MON group:
"/<MON group>/<domain_id>=<assignment_flags>"

- Child MON group of non-default CTRL_MON group:
"<CTRL_MON group>/<MON group>/<domain_id>=<assignment_flags>"

Assignment flags can be one of the following:
t MBM total event is enabled
l MBM local event is enabled
tl Both total and local MBM events are enabled
_ None of the MBM events are enabled

Signed-off-by: Babu Moger <babu.moger@amd.com>
---
v4: Added functionality to query domain specific assigment in.
rdtgroup_abmc_dom_state().

v3: New patch.
Addresses the feedback to provide the global assignment interface.
https://lore.kernel.org/lkml/c73f444b-83a1-4e9a-95d3-54c5165ee782@intel.com/
---
Documentation/arch/x86/resctrl.rst | 55 +++++++++++
arch/x86/kernel/cpu/resctrl/monitor.c | 1 +
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 129 +++++++++++++++++++++++++
3 files changed, 185 insertions(+)

diff --git a/Documentation/arch/x86/resctrl.rst b/Documentation/arch/x86/resctrl.rst
index fd050d4d22cd..255087de568d 100644
--- a/Documentation/arch/x86/resctrl.rst
+++ b/Documentation/arch/x86/resctrl.rst
@@ -281,6 +281,61 @@ with the following files:

# echo "mbm_legacy" > /sys/fs/resctrl/info/L3_MON/mbm_assign

+"mbm_assign_control":
+ Available when ABMC features are supported.
+ Reports the resctrl group and monitor status of each group.
+
+ List follows the following format:
+ "<CTRL_MON group>/<MON group>/<domain_id>=<assignment_flags>"
+
+ Format for specific type of grpups:
+
+ * Default CTRL_MON group:
+ "//<domain_id>=<assignment_flags>"
+
+ * Non-default CTRL_MON group:
+ "<CTRL_MON group>//<domain_id>=<assignment_flags>"
+
+ * Child MON group of default CTRL_MON group:
+ "/<MON group>/<domain_id>=<assignment_flags>"
+
+ * Child MON group of non-default CTRL_MON group:
+ "<CTRL_MON group>/<MON group>/<domain_id>=<assignment_flags>"
+
+ Assignment flags can be one of the following:
+ ::
+
+ t MBM total event is enabled
+ l MBM local event is enabled
+ tl Both total and local MBM events are enabled
+ _ None of the MBM events are enabled
+
+ Examples:
+ ::
+
+ # mkdir /sys/fs/resctrl/mon_groups/child_default_mon_grp
+ # mkdir /sys/fs/resctrl/non_default_ctrl_mon_grp
+ # mkdir /sys/fs/resctrl/non_default_ctrl_mon_grp/mon_groups/child_non_default_mon_grp
+
+ # cat /sys/fs/resctrl/info/L3_MON/mbm_assign_control
+ non_default_ctrl_mon_grp//0=tl;1=tl;
+ non_default_ctrl_mon_grp/child_non_default_mon_grp/0=tl;1=tl;
+ //0=tl;1=tl;
+ /child_default_mon_grp/0=tl;1=tl;
+
+ There are four resctrl groups. All the groups have total and local events are
+ enabled on domain 0 and 1.
+
+ non_default_ctrl_mon_grp// - This is a non default control mon group.
+
+ non_default_ctrl_mon_grp/child_non_default_mon_grp/ - This is a child monitor
+ group of the non default control mon group.
+
+ // - This is a default control mon group.
+
+ /child_default_mon_grp/ - This is a child monitor group of the default control
+ mon group.
+
"max_threshold_occupancy":
Read/write file provides the largest value (in
bytes) at which a previously used LLC_occupancy
diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
index ab0f4bb49bd9..f4dba02db9c0 100644
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -1083,6 +1083,7 @@ int __init rdt_get_mon_l3_config(struct rdt_resource *r)
r->mon.num_cntrs = 64;
}
resctrl_file_fflags_init("num_cntrs", RFTYPE_MON_INFO);
+ resctrl_file_fflags_init("mbm_assign_control", RFTYPE_MON_INFO);
}
}

diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index d77ff059269a..bd3a54405402 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -945,6 +945,129 @@ static ssize_t rdtgroup_mbm_assign_write(struct kernfs_open_file *of,
return ret ?: nbytes;
}

+static void rdtgroup_abmc_dom_cfg(void *info)
+{
+ u64 *msrval = info;
+
+ wrmsrl(MSR_IA32_L3_QOS_ABMC_CFG, *msrval);
+ rdmsrl(MSR_IA32_L3_QOS_ABMC_DSC, *msrval);
+}
+
+/*
+ * Writing the counter id with CfgEn=0 on L3_QOS_ABMC_CFG and reading
+ * L3_QOS_ABMC_DSC back will return configuration of the counter
+ * specified.
+ */
+static int rdtgroup_abmc_dom_state(struct rdt_domain *d, u32 ctr_id, u32 rmid)
+{
+ union l3_qos_abmc_cfg abmc_cfg = { 0 };
+
+ abmc_cfg.split.cfg_en = 0;
+ abmc_cfg.split.ctr_id = ctr_id;
+
+ smp_call_function_any(&d->cpu_mask, rdtgroup_abmc_dom_cfg,
+ &abmc_cfg, 1);
+
+ if (abmc_cfg.split.ctr_en && abmc_cfg.split.bw_src == rmid)
+ return 0;
+ else
+ return -1;
+}
+
+static char *mon_state_to_str(struct rdtgroup *rdtgrp,
+ struct rdt_domain *d, char *str)
+{
+ char *tmp = str;
+ int dom_state = ASSIGN_NONE;
+
+ /*
+ * Query the monitor state for the domain.
+ * Index 0 for evtid == QOS_L3_MBM_TOTAL_EVENT_ID
+ * Index 1 for evtid == QOS_L3_MBM_LOCAL_EVENT_ID
+ */
+ if (rdtgrp->mon.mon_state & ASSIGN_TOTAL)
+ if (!rdtgroup_abmc_dom_state(d, rdtgrp->mon.ctr_id[0], rdtgrp->mon.rmid))
+ dom_state |= ASSIGN_TOTAL;
+
+ if (rdtgrp->mon.mon_state & ASSIGN_LOCAL)
+ if (!rdtgroup_abmc_dom_state(d, rdtgrp->mon.ctr_id[1], rdtgrp->mon.rmid))
+ dom_state |= ASSIGN_LOCAL;
+
+ switch (dom_state) {
+ case ASSIGN_NONE:
+ *tmp++ = '_';
+ break;
+ case (ASSIGN_TOTAL | ASSIGN_LOCAL):
+ *tmp++ = 't';
+ *tmp++ = 'l';
+ break;
+ case ASSIGN_TOTAL:
+ *tmp++ = 't';
+ break;
+ case ASSIGN_LOCAL:
+ *tmp++ = 'l';
+ break;
+ default:
+ break;
+ }
+
+ *tmp = '\0';
+ return str;
+}
+
+static int rdtgroup_mbm_assign_control_show(struct kernfs_open_file *of,
+ struct seq_file *s, void *v)
+{
+ struct rdt_resource *r = of->kn->parent->priv;
+ struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
+ struct rdt_domain *dom;
+ struct rdtgroup *rdtg;
+ int grp_default = 0;
+ char str[10];
+
+ if (!hw_res->abmc_enabled) {
+ rdt_last_cmd_puts("ABMC feature is not enabled\n");
+ return -EINVAL;
+ }
+
+ mutex_lock(&rdtgroup_mutex);
+
+ list_for_each_entry(rdtg, &rdt_all_groups, rdtgroup_list) {
+ struct rdtgroup *crg;
+
+ if (rdtg == &rdtgroup_default) {
+ grp_default = 1;
+ seq_puts(s, "//");
+ } else {
+ grp_default = 0;
+ seq_printf(s, "%s//", rdtg->kn->name);
+ }
+
+ list_for_each_entry(dom, &r->domains, list)
+ seq_printf(s, "%d=%s;", dom->id,
+ mon_state_to_str(rdtg, dom, str));
+ seq_putc(s, '\n');
+
+ list_for_each_entry(crg, &rdtg->mon.crdtgrp_list,
+ mon.crdtgrp_list) {
+ if (grp_default)
+ seq_printf(s, "/%s/", crg->kn->name);
+ else
+ seq_printf(s, "%s/%s/", rdtg->kn->name,
+ crg->kn->name);
+
+ list_for_each_entry(dom, &r->domains, list)
+ seq_printf(s, "%d=%s;", dom->id,
+ mon_state_to_str(crg, dom, str));
+ seq_putc(s, '\n');
+ }
+ }
+
+ mutex_unlock(&rdtgroup_mutex);
+
+ return 0;
+}
+
#ifdef CONFIG_PROC_CPU_RESCTRL

/*
@@ -2143,6 +2266,12 @@ static struct rftype res_common_files[] = {
.kf_ops = &rdtgroup_kf_single_ops,
.seq_show = rdtgroup_num_cntrs_show,
},
+ {
+ .name = "mbm_assign_control",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdtgroup_mbm_assign_control_show,
+ },
{
.name = "cpus_list",
.mode = 0644,
--
2.34.1