Hi Dave, On 2/19/25 07:32, Dave Martin wrote: > On Wed, Jan 22, 2025 at 02:20:22PM -0600, Babu Moger wrote: >> 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 it >> is assigned. The assigned RMID will be tracked by the hardware until the >> user unassigns it manually. >> >> Implement an architecture-specific handler to assign and unassign the >> counter. Configure counters by writing to the L3_QOS_ABMC_CFG MSR, >> specifying the counter ID, bandwidth source (RMID), and event >> configuration. >> >> 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> >> --- > > [...] > >> diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c >> index f2bf5b13465d..ef836bb69b9b 100644 >> --- a/arch/x86/kernel/cpu/resctrl/monitor.c >> +++ b/arch/x86/kernel/cpu/resctrl/monitor.c >> @@ -1371,3 +1371,45 @@ void resctrl_arch_mon_event_config_set(void *info) > > [...] > >> +/* >> + * Send an IPI to the domain to assign the counter to RMID, event pair. >> + */ >> +int resctrl_arch_config_cntr(struct rdt_resource *r, struct rdt_mon_domain *d, >> + enum resctrl_event_id evtid, u32 rmid, u32 closid, >> + u32 cntr_id, bool assign) >> +{ >> + struct rdt_hw_mon_domain *hw_dom = resctrl_to_arch_mon_dom(d); >> + union l3_qos_abmc_cfg abmc_cfg = { 0 }; >> + struct arch_mbm_state *am; >> + >> + abmc_cfg.split.cfg_en = 1; >> + abmc_cfg.split.cntr_en = assign ? 1 : 0; >> + abmc_cfg.split.cntr_id = cntr_id; >> + abmc_cfg.split.bw_src = rmid; >> + >> + /* Update the event configuration from the domain */ >> + if (evtid == QOS_L3_MBM_TOTAL_EVENT_ID) >> + abmc_cfg.split.bw_type = hw_dom->mbm_total_cfg; >> + else >> + abmc_cfg.split.bw_type = hw_dom->mbm_local_cfg; >> + >> + smp_call_function_any(&d->hdr.cpu_mask, resctrl_abmc_config_one_amd, &abmc_cfg, 1); >> + >> + /* >> + * Reset the architectural state so that reading of hardware >> + * counter is not considered as an overflow in next update. >> + */ >> + am = get_arch_mbm_state(hw_dom, rmid, evtid); > > Is this necessary when unassigning the counter, or only when assigning? Yes. It is only required when assigning. Will add a check. thanks > >> + if (am) >> + memset(am, 0, sizeof(*am)); >> + >> + return 0; >> +} > > [...] > > Cheers > ---Dave > -- Thanks Babu Moger
