From 842e7f97d71a4116a650ec0045d6444b4377b512 Mon Sep 17 00:00:00 2001 From: Tony Luck Date: Wed, 17 Dec 2025 09:21:11 -0800 Subject: x86/resctrl: Add energy/perf choices to rdt boot option Legacy resctrl features are enumerated by X86_FEATURE_* flags. These may be overridden by quirks to disable features in the case of errata. Users can use kernel command line options to either disable a feature, or to force enable a feature that was disabled by a quirk. A different approach is needed for hardware features that do not have an X86_FEATURE_* flag. Update parsing of the "rdt=" boot parameter to call the telemetry driver directly to handle new "perf" and "energy" options that controls activation of telemetry monitoring of the named type. By itself a "perf" or "energy" option controls the forced enabling or disabling (with ! prefix) of all event groups of the named type. A ":guid" suffix allows for fine grained control per event group. [ bp: s/intel_aet_option/intel_handle_aet_option/g ] Signed-off-by: Tony Luck Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Reinette Chatre Link: https://lore.kernel.org/20251217172121.12030-1-tony.luck@intel.com --- Documentation/admin-guide/kernel-parameters.txt | 7 ++++- arch/x86/kernel/cpu/resctrl/core.c | 2 ++ arch/x86/kernel/cpu/resctrl/intel_aet.c | 38 +++++++++++++++++++++++++ arch/x86/kernel/cpu/resctrl/internal.h | 2 ++ 4 files changed, 48 insertions(+), 1 deletion(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index a8d0afde7f85..abd77f39c783 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -6325,9 +6325,14 @@ Kernel parameters rdt= [HW,X86,RDT] Turn on/off individual RDT features. List is: cmt, mbmtotal, mbmlocal, l3cat, l3cdp, l2cat, l2cdp, - mba, smba, bmec, abmc, sdciae. + mba, smba, bmec, abmc, sdciae, energy[:guid], + perf[:guid]. E.g. to turn on cmt and turn off mba use: rdt=cmt,!mba + To turn off all energy telemetry monitoring and ensure that + perf telemetry monitoring associated with guid 0x12345 + is enabled use: + rdt=!energy,perf:0x12345 reboot= [KNL] Format (x86 or x86_64): diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c index 2514f15cd9a4..e38d7fc4f427 100644 --- a/arch/x86/kernel/cpu/resctrl/core.c +++ b/arch/x86/kernel/cpu/resctrl/core.c @@ -814,6 +814,8 @@ static int __init set_rdt_options(char *str) force_off = *tok == '!'; if (force_off) tok++; + if (intel_handle_aet_option(force_off, tok)) + continue; for (o = rdt_options; o < &rdt_options[NUM_RDT_OPTIONS]; o++) { if (strcmp(tok, o->name) == 0) { if (force_off) diff --git a/arch/x86/kernel/cpu/resctrl/intel_aet.c b/arch/x86/kernel/cpu/resctrl/intel_aet.c index 9351fe5b645a..dc25e8d2527d 100644 --- a/arch/x86/kernel/cpu/resctrl/intel_aet.c +++ b/arch/x86/kernel/cpu/resctrl/intel_aet.c @@ -52,12 +52,17 @@ struct pmt_event { /** * struct event_group - Events with the same feature type ("energy" or "perf") and GUID. * @pfname: PMT feature name ("energy" or "perf") of this event group. + * Used by boot rdt= option. * @pfg: Points to the aggregated telemetry space information * returned by the intel_pmt_get_regions_by_feature() * call to the INTEL_PMT_TELEMETRY driver that contains * data for all telemetry regions of type @pfname. * Valid if the system supports the event group, * NULL otherwise. + * @force_off: True when "rdt" command line or architecture code disables + * this event group. + * @force_on: True when "rdt" command line overrides disable of this + * event group. * @guid: Unique number per XML description file. * @mmio_size: Number of bytes of MMIO registers for this group. * @num_events: Number of events in this group. @@ -67,6 +72,7 @@ struct event_group { /* Data fields for additional structures to manage this group. */ const char *pfname; struct pmt_feature_group *pfg; + bool force_off, force_on; /* Remaining fields initialized from XML file. */ u32 guid; @@ -121,6 +127,35 @@ static struct event_group *known_event_groups[] = { _peg < &known_event_groups[ARRAY_SIZE(known_event_groups)]; \ _peg++) +bool intel_handle_aet_option(bool force_off, char *tok) +{ + struct event_group **peg; + bool ret = false; + u32 guid = 0; + char *name; + + if (!tok) + return false; + + name = strsep(&tok, ":"); + if (tok && kstrtou32(tok, 16, &guid)) + return false; + + for_each_event_group(peg) { + if (strcmp(name, (*peg)->pfname)) + continue; + if (guid && (*peg)->guid != guid) + continue; + if (force_off) + (*peg)->force_off = true; + else + (*peg)->force_on = true; + ret = true; + } + + return ret; +} + static bool skip_telem_region(struct telemetry_region *tr, struct event_group *e) { if (tr->guid != e->guid) @@ -168,6 +203,9 @@ static bool enable_events(struct event_group *e, struct pmt_feature_group *p) struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_PERF_PKG].r_resctrl; int skipped_events = 0; + if (e->force_off) + return false; + if (!group_has_usable_regions(e, p)) return false; diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h index 3b228b241fb2..61a283652d39 100644 --- a/arch/x86/kernel/cpu/resctrl/internal.h +++ b/arch/x86/kernel/cpu/resctrl/internal.h @@ -236,6 +236,7 @@ void __exit intel_aet_exit(void); int intel_aet_read_event(int domid, u32 rmid, void *arch_priv, u64 *val); void intel_aet_mon_domain_setup(int cpu, int id, struct rdt_resource *r, struct list_head *add_pos); +bool intel_handle_aet_option(bool force_off, char *tok); #else static inline bool intel_aet_get_events(void) { return false; } static inline void __exit intel_aet_exit(void) { } @@ -246,6 +247,7 @@ static inline int intel_aet_read_event(int domid, u32 rmid, void *arch_priv, u64 static inline void intel_aet_mon_domain_setup(int cpu, int id, struct rdt_resource *r, struct list_head *add_pos) { } +static inline bool intel_handle_aet_option(bool force_off, char *tok) { return false; } #endif #endif /* _ASM_X86_RESCTRL_INTERNAL_H */ -- cgit v1.2.3