The ABMC feature provides an option to the user to assign a hardware counter to an RMID, event pair and monitor the bandwidth as long as the counter is assigned. The bandwidth events will be tracked by the hardware until the user changes the configuration. Each resctrl group can configure maximum two counters, one for total event and one for local event. The ABMC feature implements an MSR L3_QOS_ABMC_CFG (C000_03FDh). Configuration is done by setting the counter id, bandwidth source (RMID) and bandwidth configuration supported by BMEC (Bandwidth Monitoring Event Configuration). Attempts to read or write the MSR when ABMC is not enabled will result in a #GP(0) exception. Introduce the data structures and definitions for MSR L3_QOS_ABMC_CFG (0xC000_03FDh): ========================================================================= Bits Mnemonic Description Access Reset Type Value ========================================================================= 63 CfgEn Configuration Enable R/W 0 62 CtrEn Enable/disable counting R/W 0 61:53 – Reserved MBZ 0 52:48 CtrID Counter Identifier R/W 0 47 IsCOS BwSrc field is a CLOSID R/W 0 (not an RMID) 46:44 – Reserved MBZ 0 43:32 BwSrc Bandwidth Source R/W 0 (RMID or CLOSID) 31:0 BwType Bandwidth configuration R/W 0 to track for this counter ========================================================================== The feature details are documented 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). Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537 Signed-off-by: Babu Moger <babu.moger@xxxxxxx> --- v8: Update the configuration notes in kernel_doc. Few commit message update. v7: Removed the reference of L3_QOS_ABMC_DSC as it is not used anymore. Moved the configuration notes to kernel_doc. Adjusted the tabs for l3_qos_abmc_cfg and checkpatch seems happy. v6: Removed all the fs related changes. Added note on CfgEn,CtrEn. Removed the definitions which are not used. Removed cntr_id initialization. v5: Moved assignment flags here (path 10/19 of v4). Added MON_CNTR_UNSET definition to initialize cntr_id's. More details in commit log. Renamed few fields in l3_qos_abmc_cfg for readability. v4: Added more descriptions. Changed the name abmc_ctr_id to ctr_id. Added L3_QOS_ABMC_DSC. Used for reading the configuration. v3: No changes. v2: No changes. --- arch/x86/include/asm/msr-index.h | 1 + arch/x86/kernel/cpu/resctrl/internal.h | 33 ++++++++++++++++++++++++++ 2 files changed, 34 insertions(+) diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h index 43c9dc473aba..2c281c977342 100644 --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -1196,6 +1196,7 @@ #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 /* AMD-V MSRs */ #define MSR_VM_CR 0xc0010114 diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h index 86e3e188c119..de397468b945 100644 --- a/arch/x86/kernel/cpu/resctrl/internal.h +++ b/arch/x86/kernel/cpu/resctrl/internal.h @@ -602,6 +602,39 @@ union cpuid_0x10_x_edx { unsigned int full; }; +/* + * ABMC counters can be configured by writing to L3_QOS_ABMC_CFG. + * Reading L3_QOS_ABMC_DSC returns the configuration of the counter id + * specified in L3_QOS_ABMC_CFG.cntr_id. + * @bw_type : Bandwidth configuration(supported by BMEC) + * tracked by the @cntr_id. + * @bw_src : Bandwidth source (RMID or CLOSID). + * @reserved1 : Reserved. + * @is_clos : @bw_src field is a CLOSID (not an RMID). + * @cntr_id : Counter identifier. + * @reserved : Reserved. + * @cntr_en : Counting enable bit. + * @cfg_en : Configuration enable bit. + * + * Configuration and counting: + * cfg_en=0, : No configuration changes applied. + * cfg_en=1, cntr_en=0 : Configure cntr_id and but no counting the events. + * cfg_en=1, cntr_en=1 : Configure cntr_id and start counting the events. + */ +union l3_qos_abmc_cfg { + struct { + unsigned long bw_type :32, + bw_src :12, + reserved1: 3, + is_clos : 1, + cntr_id : 5, + reserved : 9, + cntr_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) -- 2.34.1
