The current event configuration can be changed by the user by writing
to the configuration file /sys/fs/resctrl/info/L3_MON/mbm_total_config.
The event configuration settings are domain specific. Changing the
configuration on one CPU in a domain would affect the whole 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 all the reads on domain 0, run
the command.
	$echo  0:0x33 > /sys/fs/resctrl/info/L3_MON/mbm_total_config

To change the mbm_total_bytes to count all the slow memory reads on
domain 1, run the command.
	$echo  1:0x30 > /sys/fs/resctrl/info/L3_MON/mbm_total_config

Signed-off-by: Babu Moger <babu.moger@amd.com>
---
 arch/x86/kernel/cpu/resctrl/internal.h |   23 +++++
 arch/x86/kernel/cpu/resctrl/rdtgroup.c |  139 ++++++++++++++++++++++++++++++++
 2 files changed, 162 insertions(+)

diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index 44d3f18dfd69..d19ade3b5ef3 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -51,6 +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 27bf6ade0dbf..c1d43d03846a 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -1491,6 +1491,144 @@ static int mbm_local_config_show(struct kernfs_open_file *of,
 	return 0;
 }
 
+void mon_event_config_write(void *info)
+{
+	struct mon_config_info *mon_info = info;
+	u32 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;
+	}
+
+	wrmsr(MSR_IA32_EVT_CFG_BASE + msr_index, mon_info->mon_config, 0);
+}
+
+int mbm_config_write(struct rdt_resource *r, struct rdt_domain *d,
+		     u32 evtid, u32 val)
+{
+	struct mon_config_info mon_info = {0};
+	cpumask_var_t cpu_mask;
+	int ret = 0, cpu;
+
+	rdt_last_cmd_clear();
+
+	/* 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;
+	}
+
+	cpus_read_lock();
+
+	if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL)) {
+		rdt_last_cmd_puts("cpu_mask allocation failed\n");
+		ret = -ENOMEM;
+		goto e_unlock;
+	}
+
+	/*
+	 * Read the current config value first. If both are same then
+	 * we dont need to write it again.
+	 */
+	mon_info.evtid = evtid;
+	mondata_config_read(d, &mon_info);
+	if (mon_info.mon_config == val)
+		goto e_cpumask;
+
+	mon_info.mon_config = val;
+
+	/* Pick all the CPUs in the domain instance */
+	for_each_cpu(cpu, &d->cpu_mask)
+		cpumask_set_cpu(cpu, cpu_mask);
+
+	/* Update MSR_IA32_EVT_CFG_BASE MSR on all the CPUs in cpu_mask */
+	on_each_cpu_mask(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.
+	 */
+	memset(d->mbm_local, 0, sizeof(struct mbm_state) * r->num_rmid);
+	memset(d->mbm_total, 0, sizeof(struct mbm_state) * r->num_rmid);
+
+e_cpumask:
+	free_cpumask_var(cpu_mask);
+
+e_unlock:
+	cpus_read_unlock();
+
+	return ret;
+}
+
+unsigned int mon_config_parse(struct rdt_resource *r, char *tok, u32 evtid)
+{
+	char *dom_str = NULL, *id_str;
+	struct rdt_domain *d;
+	unsigned long dom_id, val;
+	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 (!dom_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("Missing '=' or 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(r, d, evtid, val);
+			if (ret)
+				return -EINVAL;
+			goto next;
+		}
+	}
+
+	return -EINVAL;
+}
+
+static ssize_t mbm_total_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;
+
+	rdt_last_cmd_clear();
+
+	buf[nbytes - 1] = '\0';
+
+	ret = mon_config_parse(r, buf, QOS_L3_MBM_TOTAL_EVENT_ID);
+
+	return ret ?: nbytes;
+}
+
 /* rdtgroup information files for one cache resource. */
 static struct rftype res_common_files[] = {
 	{
@@ -1594,6 +1732,7 @@ static struct rftype res_common_files[] = {
 		.mode		= 0644,
 		.kf_ops		= &rdtgroup_kf_single_ops,
 		.seq_show	= mbm_total_config_show,
+		.write		= mbm_total_config_write,
 	},
 	{
 		.name		= "mbm_local_config",

Hi, Babu,

> diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> index 27bf6ade0dbf..c1d43d03846a 100644
> --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> @@ -1491,6 +1491,144 @@ static int mbm_local_config_show(struct
> kernfs_open_file *of,
>  	return 0;
>  }
> 
> +void mon_event_config_write(void *info) {

Should this function be static?

> +	struct mon_config_info *mon_info = info;
> +	u32 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;
> +	}
> +
> +	wrmsr(MSR_IA32_EVT_CFG_BASE + msr_index, mon_info->mon_config,
> 0); }
> +
> +int mbm_config_write(struct rdt_resource *r, struct rdt_domain *d,
> +		     u32 evtid, u32 val)
> +{
> +	struct mon_config_info mon_info = {0};
> +	cpumask_var_t cpu_mask;
> +	int ret = 0, cpu;
> +
> +	rdt_last_cmd_clear();
> +
> +	/* 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;
> +	}
> +
> +	cpus_read_lock();
> +
> +	if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL)) {
> +		rdt_last_cmd_puts("cpu_mask allocation failed\n");
> +		ret = -ENOMEM;
> +		goto e_unlock;
> +	}
> +
> +	/*
> +	 * Read the current config value first. If both are same then
> +	 * we dont need to write it again.
> +	 */
> +	mon_info.evtid = evtid;
> +	mondata_config_read(d, &mon_info);
> +	if (mon_info.mon_config == val)
> +		goto e_cpumask;
> +
> +	mon_info.mon_config = val;
> +
> +	/* Pick all the CPUs in the domain instance */
> +	for_each_cpu(cpu, &d->cpu_mask)
> +		cpumask_set_cpu(cpu, cpu_mask);
> +
> +	/* Update MSR_IA32_EVT_CFG_BASE MSR on all the CPUs in cpu_mask
> */
> +	on_each_cpu_mask(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.
> +	 */
> +	memset(d->mbm_local, 0, sizeof(struct mbm_state) * r->num_rmid);
> +	memset(d->mbm_total, 0, sizeof(struct mbm_state) * r->num_rmid);
> +
> +e_cpumask:
> +	free_cpumask_var(cpu_mask);
> +
> +e_unlock:
> +	cpus_read_unlock();
> +
> +	return ret;
> +}
> +
> +unsigned int mon_config_parse(struct rdt_resource *r, char *tok, u32
> +evtid) {

Should this function be static?

> +	char *dom_str = NULL, *id_str;
> +	struct rdt_domain *d;
> +	unsigned long dom_id, val;
> +	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 (!dom_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("Missing '=' or 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(r, d, evtid, val);
> +			if (ret)
> +				return -EINVAL;
> +			goto next;
> +		}
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static ssize_t mbm_total_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;
> +
> +	rdt_last_cmd_clear();
> +
> +	buf[nbytes - 1] = '\0';
> +
> +	ret = mon_config_parse(r, buf, QOS_L3_MBM_TOTAL_EVENT_ID);
> +
> +	return ret ?: nbytes;
> +}
> +
>  /* rdtgroup information files for one cache resource. */  static struct rftype
> res_common_files[] = {
>  	{
> @@ -1594,6 +1732,7 @@ static struct rftype res_common_files[] = {
>  		.mode		= 0644,
>  		.kf_ops		= &rdtgroup_kf_single_ops,
>  		.seq_show	= mbm_total_config_show,
> +		.write		= mbm_total_config_write,
>  	},
>  	{
>  		.name		= "mbm_local_config",
> 

Thanks.

-Fenghua

[AMD Official Use Only - General]

Hi Fenghua,


> -----Original Message-----
> From: Yu, Fenghua <fenghua.yu@intel.com>
> Sent: Tuesday, September 27, 2022 5:32 PM
> To: Moger, Babu <Babu.Moger@amd.com>; corbet@lwn.net; Chatre, Reinette
> <reinette.chatre@intel.com>; tglx@linutronix.de; mingo@redhat.com;
> bp@alien8.de
> Cc: 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; Bae, Chang Seok <chang.seok.bae@intel.com>;
> pawan.kumar.gupta@linux.intel.com; jmattson@google.com;
> daniel.sneddon@linux.intel.com; Das1, Sandipan <Sandipan.Das@amd.com>;
> Luck, Tony <tony.luck@intel.com>; james.morse@arm.com; linux-
> doc@vger.kernel.org; linux-kernel@vger.kernel.org; bagasdotme@gmail.com;
> Eranian, Stephane <eranian@google.com>
> Subject: RE: [PATCH v5 09/12] x86/resctrl: Add sysfs interface to write
> mbm_total_bytes event configuration
> 
> Hi, Babu,
> 
> > diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> > b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> > index 27bf6ade0dbf..c1d43d03846a 100644
> > --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> > +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> > @@ -1491,6 +1491,144 @@ static int mbm_local_config_show(struct
> > kernfs_open_file *of,
> >  	return 0;
> >  }
> >
> > +void mon_event_config_write(void *info) {
> 
> Should this function be static?

Sure.
> 
> > +	struct mon_config_info *mon_info = info;
> > +	u32 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;
> > +	}
> > +
> > +	wrmsr(MSR_IA32_EVT_CFG_BASE + msr_index, mon_info-
> >mon_config,
> > 0); }
> > +
> > +int mbm_config_write(struct rdt_resource *r, struct rdt_domain *d,
> > +		     u32 evtid, u32 val)
> > +{
> > +	struct mon_config_info mon_info = {0};
> > +	cpumask_var_t cpu_mask;
> > +	int ret = 0, cpu;
> > +
> > +	rdt_last_cmd_clear();
> > +
> > +	/* 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;
> > +	}
> > +
> > +	cpus_read_lock();
> > +
> > +	if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL)) {
> > +		rdt_last_cmd_puts("cpu_mask allocation failed\n");
> > +		ret = -ENOMEM;
> > +		goto e_unlock;
> > +	}
> > +
> > +	/*
> > +	 * Read the current config value first. If both are same then
> > +	 * we dont need to write it again.
> > +	 */
> > +	mon_info.evtid = evtid;
> > +	mondata_config_read(d, &mon_info);
> > +	if (mon_info.mon_config == val)
> > +		goto e_cpumask;
> > +
> > +	mon_info.mon_config = val;
> > +
> > +	/* Pick all the CPUs in the domain instance */
> > +	for_each_cpu(cpu, &d->cpu_mask)
> > +		cpumask_set_cpu(cpu, cpu_mask);
> > +
> > +	/* Update MSR_IA32_EVT_CFG_BASE MSR on all the CPUs in cpu_mask
> > */
> > +	on_each_cpu_mask(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.
> > +	 */
> > +	memset(d->mbm_local, 0, sizeof(struct mbm_state) * r->num_rmid);
> > +	memset(d->mbm_total, 0, sizeof(struct mbm_state) * r->num_rmid);
> > +
> > +e_cpumask:
> > +	free_cpumask_var(cpu_mask);
> > +
> > +e_unlock:
> > +	cpus_read_unlock();
> > +
> > +	return ret;
> > +}
> > +
> > +unsigned int mon_config_parse(struct rdt_resource *r, char *tok, u32
> > +evtid) {
> 
> Should this function be static?

Sure. Thanks
Babu
> 
> > +	char *dom_str = NULL, *id_str;
> > +	struct rdt_domain *d;
> > +	unsigned long dom_id, val;
> > +	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 (!dom_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("Missing '=' or 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(r, d, evtid, val);
> > +			if (ret)
> > +				return -EINVAL;
> > +			goto next;
> > +		}
> > +	}
> > +
> > +	return -EINVAL;
> > +}
> > +
> > +static ssize_t mbm_total_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;
> > +
> > +	rdt_last_cmd_clear();
> > +
> > +	buf[nbytes - 1] = '\0';
> > +
> > +	ret = mon_config_parse(r, buf, QOS_L3_MBM_TOTAL_EVENT_ID);
> > +
> > +	return ret ?: nbytes;
> > +}
> > +
> >  /* rdtgroup information files for one cache resource. */  static
> > struct rftype res_common_files[] = {
> >  	{
> > @@ -1594,6 +1732,7 @@ static struct rftype res_common_files[] = {
> >  		.mode		= 0644,
> >  		.kf_ops		= &rdtgroup_kf_single_ops,
> >  		.seq_show	= mbm_total_config_show,
> > +		.write		= mbm_total_config_write,
> >  	},
> >  	{
> >  		.name		= "mbm_local_config",
> >
> 
> Thanks.
> 
> -Fenghua