Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Received-SPF: Pass (protection.outlook.com: domain of amd.com designates
 165.204.84.17 as permitted sender) receiver=protection.outlook.com;
 client-ip=165.204.84.17; helo=SATLEXMB04.amd.com; pr=C
From:   Babu Moger <babu.moger@amd.com>
To:     <corbet@lwn.net>, <reinette.chatre@intel.com>,
        <tglx@linutronix.de>, <mingo@redhat.com>, <bp@alien8.de>
CC:     <fenghua.yu@intel.com>, <dave.hansen@linux.intel.com>,
        <x86@kernel.org>, <hpa@zytor.com>, <paulmck@kernel.org>,
        <akpm@linux-foundation.org>, <quic_neeraju@quicinc.com>,
        <rdunlap@infradead.org>, <damien.lemoal@opensource.wdc.com>,
        <songmuchun@bytedance.com>, <peterz@infradead.org>,
        <jpoimboe@kernel.org>, <pbonzini@redhat.com>, <babu.moger@amd.com>,
        <chang.seok.bae@intel.com>, <pawan.kumar.gupta@linux.intel.com>,
        <jmattson@google.com>, <daniel.sneddon@linux.intel.com>,
        <sandipan.das@amd.com>, <tony.luck@intel.com>,
        <james.morse@arm.com>, <linux-doc@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <bagasdotme@gmail.com>,
        <eranian@google.com>, <christophe.leroy@csgroup.eu>,
        <jarkko@kernel.org>, <adrian.hunter@intel.com>,
        <quic_jiles@quicinc.com>, <peternewman@google.com>
Subject: [PATCH v10 11/13] x86/resctrl: Add interface to write mbm_total_bytes_config
Date:   Thu, 22 Dec 2022 17:31:25 -0600
Message-ID: <20221222233127.910538-12-babu.moger@amd.com>
In-Reply-To: <20221222233127.910538-1-babu.moger@amd.com>
References: <20221222233127.910538-1-babu.moger@amd.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Content-Type: text/plain
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 22 Dec 2022 23:31:55.3031
 (UTC)
X-MS-Exchange-CrossTenant-Network-Message-Id: 0c003c72-3896-4b17-c003-08dae474b671
X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d
X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[SATLEXMB04.amd.com]
X-MS-Exchange-CrossTenant-AuthSource: CY4PEPF0000C97C.namprd02.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Anonymous
X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem
X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH2PR12MB4200
X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED,
        DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE,
        RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_PASS autolearn=ham
        autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

The event configuration for mbm_total_bytes can be changed by the user by
writing to the file /sys/fs/resctrl/info/L3_MON/mbm_total_bytes_config.

The event configuration settings are domain specific and affect all the
CPUs in the domain.

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
====  ===========================================================

For example:
To change the mbm_total_bytes to count only reads on domain 0, the bits
0, 1, 4 and 5 needs to be set, which is 110011b (in hex 0x33). Run the
command.
        $echo  0=0x33 > /sys/fs/resctrl/info/L3_MON/mbm_total_bytes_config

To change the mbm_total_bytes to count all the slow memory reads on
domain 1, the bits 4 and 5 needs to be set which is 110000b (in hex 0x30).
Run the command.
        $echo  1=0x30 > /sys/fs/resctrl/info/L3_MON/mbm_total_bytes_config

Signed-off-by: Babu Moger <babu.moger@amd.com>
---
 arch/x86/kernel/cpu/resctrl/monitor.c  |  17 ++++
 arch/x86/kernel/cpu/resctrl/rdtgroup.c | 126 ++++++++++++++++++++++++-
 include/linux/resctrl.h                |  11 +++
 3 files changed, 153 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
index 7c8a3a745041..c50c43656bdb 100644
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -176,6 +176,23 @@ void resctrl_arch_reset_rmid(struct rdt_resource *r, struct rdt_domain *d,
 		memset(am, 0, sizeof(*am));
 }
 
+/*
+ * Assumes that hardware counters are also reset and thus that there is
+ * no need to record initial non-zero counts.
+ */
+void resctrl_arch_reset_rmid_all(struct rdt_resource *r, struct rdt_domain *d)
+{
+	struct rdt_hw_domain *hw_dom = resctrl_to_arch_dom(d);
+
+	if (is_mbm_total_enabled())
+		memset(hw_dom->arch_mbm_total, 0,
+		       sizeof(*hw_dom->arch_mbm_total) * r->num_rmid);
+
+	if (is_mbm_local_enabled())
+		memset(hw_dom->arch_mbm_local, 0,
+		       sizeof(*hw_dom->arch_mbm_local) * r->num_rmid);
+}
+
 static u64 mbm_overflow_count(u64 prev_msr, u64 cur_msr, unsigned int width)
 {
 	u64 shift = 64 - width, chunks;
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 43e2a866e8e0..acaf19f5d65b 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -1515,6 +1515,129 @@ static int mbm_local_bytes_config_show(struct kernfs_open_file *of,
 	return 0;
 }
 
+static void mon_event_config_write(void *info)
+{
+	struct mon_config_info *mon_info = info;
+	unsigned int index;
+
+	index = mon_event_config_index_get(mon_info->evtid);
+	if (index == INVALID_CONFIG_INDEX) {
+		pr_warn_once("Invalid event id %d\n", mon_info->evtid);
+		return;
+	}
+	wrmsr(MSR_IA32_EVT_CFG_BASE + index, mon_info->mon_config, 0);
+}
+
+static int mbm_config_write_domain(struct rdt_resource *r,
+				   struct rdt_domain *d, u32 evtid, u32 val)
+{
+	struct mon_config_info mon_info = {0};
+	int ret = 0;
+
+	/* mon_config cannot be more than the supported set of events */
+	if (val > MAX_EVT_CONFIG_BITS) {
+		rdt_last_cmd_puts("Invalid event configuration\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * Read the current config value first. If both are the same then
+	 * no need to write it again.
+	 */
+	mon_info.evtid = evtid;
+	mondata_config_read(d, &mon_info);
+	if (mon_info.mon_config == val)
+		goto out;
+
+	mon_info.mon_config = val;
+
+	/*
+	 * Update MSR_IA32_EVT_CFG_BASE MSR on one of the CPUs in the
+	 * domain. The MSRs offset from MSR MSR_IA32_EVT_CFG_BASE
+	 * are scoped at the domain level. Writing any of these MSRs
+	 * on one CPU is observed by all the CPUs in the domain.
+	 */
+	smp_call_function_any(&d->cpu_mask, mon_event_config_write,
+			      &mon_info, 1);
+
+	/*
+	 * When an Event Configuration is changed, the bandwidth counters
+	 * for all RMIDs and Events will be cleared by the hardware. The
+	 * hardware also sets MSR_IA32_QM_CTR.Unavailable (bit 62) for
+	 * every RMID on the next read to any event for every RMID.
+	 * Subsequent reads will have MSR_IA32_QM_CTR.Unavailable (bit 62)
+	 * cleared while it is tracked by the hardware. Clear the
+	 * mbm_local and mbm_total counts for all the RMIDs.
+	 */
+	resctrl_arch_reset_rmid_all(r, d);
+
+out:
+	return ret;
+}
+
+static int mon_config_write(struct rdt_resource *r, char *tok, u32 evtid)
+{
+	char *dom_str = NULL, *id_str;
+	unsigned long dom_id, val;
+	struct rdt_domain *d;
+	int ret = 0;
+
+next:
+	if (!tok || tok[0] == '\0')
+		return 0;
+
+	/* Start processing the strings for each domain */
+	dom_str = strim(strsep(&tok, ";"));
+	id_str = strsep(&dom_str, "=");
+
+	if (!id_str || kstrtoul(id_str, 10, &dom_id)) {
+		rdt_last_cmd_puts("Missing '=' or non-numeric domain id\n");
+		return -EINVAL;
+	}
+
+	if (!dom_str || kstrtoul(dom_str, 16, &val)) {
+		rdt_last_cmd_puts("Non-numeric event configuration value\n");
+		return -EINVAL;
+	}
+
+	list_for_each_entry(d, &r->domains, list) {
+		if (d->id == dom_id) {
+			ret = mbm_config_write_domain(r, d, evtid, val);
+			if (ret)
+				return -EINVAL;
+			goto next;
+		}
+	}
+
+	return -EINVAL;
+}
+
+static ssize_t mbm_total_bytes_config_write(struct kernfs_open_file *of,
+					    char *buf, size_t nbytes,
+					    loff_t off)
+{
+	struct rdt_resource *r = of->kn->parent->priv;
+	int ret;
+
+	/* Valid input requires a trailing newline */
+	if (nbytes == 0 || buf[nbytes - 1] != '\n')
+		return -EINVAL;
+
+	cpus_read_lock();
+	mutex_lock(&rdtgroup_mutex);
+
+	rdt_last_cmd_clear();
+
+	buf[nbytes - 1] = '\0';
+
+	ret = mon_config_write(r, buf, QOS_L3_MBM_TOTAL_EVENT_ID);
+
+	mutex_unlock(&rdtgroup_mutex);
+	cpus_read_unlock();
+
+	return ret ?: nbytes;
+}
+
 /* rdtgroup information files for one cache resource. */
 static struct rftype res_common_files[] = {
 	{
@@ -1615,9 +1738,10 @@ static struct rftype res_common_files[] = {
 	},
 	{
 		.name		= "mbm_total_bytes_config",
-		.mode		= 0444,
+		.mode		= 0644,
 		.kf_ops		= &rdtgroup_kf_single_ops,
 		.seq_show	= mbm_total_bytes_config_show,
+		.write		= mbm_total_bytes_config_write,
 	},
 	{
 		.name		= "mbm_local_bytes_config",
diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
index 0cee154abc9f..8334eeacfec5 100644
--- a/include/linux/resctrl.h
+++ b/include/linux/resctrl.h
@@ -250,6 +250,17 @@ int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_domain *d,
 void resctrl_arch_reset_rmid(struct rdt_resource *r, struct rdt_domain *d,
 			     u32 rmid, enum resctrl_event_id eventid);
 
+/**
+ * resctrl_arch_reset_rmid_all() - Reset all private state associated with
+ *				   all rmids and eventids.
+ * @r:		The resctrl resource.
+ * @d:		The domain for which all architectural counter state will
+ *		be cleared.
+ *
+ * This can be called from any CPU.
+ */
+void resctrl_arch_reset_rmid_all(struct rdt_resource *r, struct rdt_domain *d);
+
 extern unsigned int resctrl_rmid_realloc_threshold;
 extern unsigned int resctrl_rmid_realloc_limit;
 
-- 
2.34.1