The current 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 will 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@xxxxxxx> --- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 130 ++++++++++++++++++++++++++++++++ 1 file changed, 129 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index 18f9588a41cf..0cdccb69386e 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -1505,6 +1505,133 @@ 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; + u32 index; + + index = mon_event_config_index_get(mon_info->evtid); + if (index >= MAX_CONFIG_EVENTS) { + 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(struct rdt_resource *r, struct rdt_domain *d, + u32 evtid, u32 val) +{ + struct mon_config_info mon_info = {0}; + int ret = 0; + + 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; + } + + /* + * Read the current config value first. If both are same then + * we don't need to write it again. + */ + mon_info.evtid = evtid; + mondata_config_read(d, &mon_info); + if (mon_info.mon_config == val) + goto write_exit; + + mon_info.mon_config = val; + + /* + * Update MSR_IA32_EVT_CFG_BASE MSRs on all 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 supposed to be observed by all CPUs in the + * domain. However, the hardware team recommends to update + * these MSRs on all the CPUs in the domain. + */ + on_each_cpu_mask(&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. + */ + memset(d->mbm_local, 0, sizeof(struct mbm_state) * r->num_rmid); + memset(d->mbm_total, 0, sizeof(struct mbm_state) * r->num_rmid); + +write_exit: + return ret; +} + +static int mon_config_parse(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 (!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_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_parse(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[] = { { @@ -1605,9 +1732,10 @@ 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",