From: Babu Moger Date: Fri, 5 Sep 2025 21:34:07 +0000 (-0500) Subject: x86,fs/resctrl: Detect Assignable Bandwidth Monitoring feature details X-Git-Tag: v6.18-rc1~186^2~26 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=13390861b426e936db20d675804a5b405622bc79;p=thirdparty%2Fkernel%2Flinux.git x86,fs/resctrl: Detect Assignable Bandwidth Monitoring feature details ABMC feature details are reported via CPUID Fn8000_0020_EBX_x5. Bits Description 15:0 MAX_ABMC Maximum Supported Assignable Bandwidth Monitoring Counter ID + 1 The ABMC feature details are documented in APM [1] available from [2]. [1] AMD64 Architecture Programmer's Manual Volume 2: System Programming Publication # 24593 Revision 3.41 section 19.3.3.3 Assignable Bandwidth Monitoring (ABMC). Detect the feature and number of assignable counters supported. For backward compatibility, upon detecting the assignable counter feature, enable the mbm_total_bytes and mbm_local_bytes events that users are familiar with as part of original L3 MBM support. Signed-off-by: Babu Moger Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Reinette Chatre Link: https://lore.kernel.org/cover.1757108044.git.babu.moger@amd.com Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537 # [2] --- diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c index 267e9206a9992..2e68aa02ad3f4 100644 --- a/arch/x86/kernel/cpu/resctrl/core.c +++ b/arch/x86/kernel/cpu/resctrl/core.c @@ -883,6 +883,8 @@ static __init bool get_rdt_mon_resources(void) resctrl_enable_mon_event(QOS_L3_MBM_LOCAL_EVENT_ID); ret = true; } + if (rdt_cpu_has(X86_FEATURE_ABMC)) + ret = true; if (!ret) return false; @@ -978,7 +980,7 @@ static enum cpuhp_state rdt_online; /* Runs once on the BSP during boot. */ void resctrl_cpu_detect(struct cpuinfo_x86 *c) { - if (!cpu_has(c, X86_FEATURE_CQM_LLC)) { + if (!cpu_has(c, X86_FEATURE_CQM_LLC) && !cpu_has(c, X86_FEATURE_ABMC)) { c->x86_cache_max_rmid = -1; c->x86_cache_occ_scale = -1; c->x86_cache_mbm_width_offset = -1; @@ -990,7 +992,8 @@ void resctrl_cpu_detect(struct cpuinfo_x86 *c) if (cpu_has(c, X86_FEATURE_CQM_OCCUP_LLC) || cpu_has(c, X86_FEATURE_CQM_MBM_TOTAL) || - cpu_has(c, X86_FEATURE_CQM_MBM_LOCAL)) { + cpu_has(c, X86_FEATURE_CQM_MBM_LOCAL) || + cpu_has(c, X86_FEATURE_ABMC)) { u32 eax, ebx, ecx, edx; /* QoS sub-leaf, EAX=0Fh, ECX=1 */ diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c index 2558b1bdef8b5..0a695ce68f462 100644 --- a/arch/x86/kernel/cpu/resctrl/monitor.c +++ b/arch/x86/kernel/cpu/resctrl/monitor.c @@ -339,6 +339,7 @@ int __init rdt_get_mon_l3_config(struct rdt_resource *r) unsigned int mbm_offset = boot_cpu_data.x86_cache_mbm_width_offset; struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r); unsigned int threshold; + u32 eax, ebx, ecx, edx; snc_nodes_per_l3_cache = snc_get_config(); @@ -368,14 +369,18 @@ int __init rdt_get_mon_l3_config(struct rdt_resource *r) */ resctrl_rmid_realloc_threshold = resctrl_arch_round_mon_val(threshold); - if (rdt_cpu_has(X86_FEATURE_BMEC)) { - u32 eax, ebx, ecx, edx; - + if (rdt_cpu_has(X86_FEATURE_BMEC) || rdt_cpu_has(X86_FEATURE_ABMC)) { /* Detect list of bandwidth sources that can be tracked */ cpuid_count(0x80000020, 3, &eax, &ebx, &ecx, &edx); r->mon.mbm_cfg_mask = ecx & MAX_EVT_CONFIG_BITS; } + if (rdt_cpu_has(X86_FEATURE_ABMC)) { + r->mon.mbm_cntr_assignable = true; + cpuid_count(0x80000020, 5, &eax, &ebx, &ecx, &edx); + r->mon.num_mbm_cntrs = (ebx & GENMASK(15, 0)) + 1; + } + r->mon_capable = true; return 0; diff --git a/fs/resctrl/monitor.c b/fs/resctrl/monitor.c index e0dfa5fb969e4..b578451de2b50 100644 --- a/fs/resctrl/monitor.c +++ b/fs/resctrl/monitor.c @@ -922,6 +922,13 @@ int resctrl_mon_resource_init(void) else if (resctrl_is_mon_event_enabled(QOS_L3_MBM_TOTAL_EVENT_ID)) mba_mbps_default_event = QOS_L3_MBM_TOTAL_EVENT_ID; + if (r->mon.mbm_cntr_assignable) { + if (!resctrl_is_mon_event_enabled(QOS_L3_MBM_TOTAL_EVENT_ID)) + resctrl_enable_mon_event(QOS_L3_MBM_TOTAL_EVENT_ID); + if (!resctrl_is_mon_event_enabled(QOS_L3_MBM_LOCAL_EVENT_ID)) + resctrl_enable_mon_event(QOS_L3_MBM_LOCAL_EVENT_ID); + } + return 0; } diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index fe2af6cb96d4b..eb80cc233be43 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -260,10 +260,14 @@ enum resctrl_schema_fmt { * @num_rmid: Number of RMIDs available. * @mbm_cfg_mask: Memory transactions that can be tracked when bandwidth * monitoring events can be configured. + * @num_mbm_cntrs: Number of assignable counters. + * @mbm_cntr_assignable:Is system capable of supporting counter assignment? */ struct resctrl_mon { int num_rmid; unsigned int mbm_cfg_mask; + int num_mbm_cntrs; + bool mbm_cntr_assignable; }; /**