Hi Babu, On 3/28/2024 6:06 PM, Babu Moger wrote: > ABMC (Bandwidth Monitoring Event Configuration) counters can be configured > by writing to L3_QOS_ABMC_CFG MSR. When ABMC is enabled, the user can > configure a counter by writing to L3_QOS_ABMC_CFG setting the CfgEn field > while specifying the Bandwidth Source, Bandwidth Types, and Counter > Identifier. Add the MSR definition and individual field definitions. > > MSR L3_QOS_ABMC_CFG (C000_03FDh) definitions. > > ========================================================================== > Bits Mnemonic Description Access Type Reset Value > ========================================================================== > 63 CfgEn Configuration Enable R/W 0 > > 62 CtrEn Counter Enable R/W 0 > > 61:53 – Reserved MBZ 0 > > 52:48 CtrID Counter Identifier R/W 0 > > 47 IsCOS BwSrc field is a COS R/W 0 > (not an RMID) > > 46:44 – Reserved MBZ 0 > > 43:32 BwSrc Bandwidth Source R/W 0 > (RMID or COS) > > 31:0 BwType Bandwidth types to R/W 0 > track for this counter > ========================================================================== > > The feature details are documentd in the APM listed below [1]. > [1] AMD64 Architecture Programmer's Manual Volume 2: System Programming > Publication # 24593 Revision 3.41 section 19.3.3.3 Assignable Bandwidth > Monitoring (ABMC). This changelog is purely a summary of the hardware architecture. I have not come across a clear explanation on how this architecture is intended to be supported by resctrl. When would resctrl need/want to set particular fields? What is the mapping to resctrl? > > Signed-off-by: Babu Moger <babu.moger@xxxxxxx> > Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537 > > --- > v3: No changes. > v2: No changes. > --- > arch/x86/include/asm/msr-index.h | 1 + > arch/x86/kernel/cpu/resctrl/internal.h | 23 +++++++++++++++++++++++ > 2 files changed, 24 insertions(+) > > diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h > index f16ee50b1a23..ab01abfab089 100644 > --- a/arch/x86/include/asm/msr-index.h > +++ b/arch/x86/include/asm/msr-index.h > @@ -1166,6 +1166,7 @@ > #define MSR_IA32_SMBA_BW_BASE 0xc0000280 > #define MSR_IA32_EVT_CFG_BASE 0xc0000400 > #define MSR_IA32_L3_QOS_EXT_CFG 0xc00003ff > +#define MSR_IA32_L3_QOS_ABMC_CFG 0xc00003fd > > /* MSR_IA32_VMX_MISC bits */ > #define MSR_IA32_VMX_MISC_INTEL_PT (1ULL << 14) > diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h > index b559b3a4555e..41b06d46ea74 100644 > --- a/arch/x86/kernel/cpu/resctrl/internal.h > +++ b/arch/x86/kernel/cpu/resctrl/internal.h > @@ -106,6 +106,9 @@ cpumask_any_housekeeping(const struct cpumask *mask, int exclude_cpu) > #define ASSIGN_TOTAL BIT(0) > #define ASSIGN_LOCAL BIT(1) > > +/* Maximum assignable counters per resctrl group */ > +#define MAX_ASSIGN_CNTRS 2 > + > struct rdt_fs_context { > struct kernfs_fs_context kfc; > bool enable_cdpl2; > @@ -210,6 +213,7 @@ enum rdtgrp_mode { > * @crdtgrp_list: child rdtgroup node list > * @rmid: rmid for this rdtgroup > * @mon_state: Assignment state of the group > + * @abmc_ctr_id: ABMC counterids assigned to this group > */ > struct mongroup { > struct kernfs_node *mon_data_kn; > @@ -217,6 +221,7 @@ struct mongroup { > struct list_head crdtgrp_list; > u32 rmid; > u32 mon_state; > + u32 abmc_ctr_id[MAX_ASSIGN_CNTRS]; > }; > > /** > @@ -566,6 +571,24 @@ union cpuid_0x10_x_edx { > unsigned int full; > }; > > +/* > + * L3_QOS_ABMC_CFG MSR details. ABMC counters can be configured > + * by writing to L3_QOS_ABMC_CFG. There are many fields in this structure ... how is resctrl expected to set these fields in order to configure a counter? Please expand the comments. > + */ > +union l3_qos_abmc_cfg { > + struct { > + unsigned long bw_type :32, > + bw_src :12, > + rsvrd1 : 3, Considering how "reserved" is spelled it is unexpected to see "rsvrd" > + is_cos : 1, > + ctr_id : 5, > + rsvrd : 9, > + ctr_en : 1, > + cfg_en : 1; > + } split; > + unsigned long full; > +}; > + > void rdt_last_cmd_clear(void); > void rdt_last_cmd_puts(const char *s); > __printf(1, 2) Reinette
