Hi Reinette,
On 6/13/24 20:43, Reinette Chatre wrote:
> Hi Babu,
>
> On 5/24/24 5:23 AM, Babu Moger wrote:
>> If the BMEC (Bandwidth Monitoring Event Configuration) feature is
>> supported, the bandwidth events can be configured to track specific
>> events. The event configuration is domain specific. ABMC (Assignable
>> Bandwidth Monitoring Counters) feature needs event configuration
>> information to assign hardware counter to an RMID. Event configurations
>> are not stored in resctrl but instead always read from or written to
>> hardware directly when prompted by user space.
>>
>> Read the event configuration from the hardware during the domain
>> initialization. Save the configuration information in the rdt_hw_domain,
>> so it can be used for counter assignment.
>>
>> Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
>> ---
>> v4: Read the configuration information from the hardware to initialize.
>> Added few commit messages.
>> Fixed the tab spaces.
>>
>> v3: Minor changes related to rebase in mbm_config_write_domain.
>>
>> v2: No changes.
>> ---
>> arch/x86/kernel/cpu/resctrl/core.c | 2 ++
>> arch/x86/kernel/cpu/resctrl/internal.h | 5 +++++
>> arch/x86/kernel/cpu/resctrl/monitor.c | 21 +++++++++++++++++++++
>> 3 files changed, 28 insertions(+)
>>
>> diff --git a/arch/x86/kernel/cpu/resctrl/core.c
>> b/arch/x86/kernel/cpu/resctrl/core.c
>> index ec93f6a50308..856c46d12177 100644
>> --- a/arch/x86/kernel/cpu/resctrl/core.c
>> +++ b/arch/x86/kernel/cpu/resctrl/core.c
>> @@ -542,6 +542,8 @@ static void domain_add_cpu(int cpu, struct
>> rdt_resource *r)
>> return;
>> }
>> + arch_domain_mbm_evt_config(hw_dom);
>> +
>> list_add_tail_rcu(&d->list, add_pos);
>> err = resctrl_online_domain(r, d);
>> diff --git a/arch/x86/kernel/cpu/resctrl/internal.h
>> b/arch/x86/kernel/cpu/resctrl/internal.h
>> index 5e7e76cd512f..60a1ca0a11a7 100644
>> --- a/arch/x86/kernel/cpu/resctrl/internal.h
>> +++ b/arch/x86/kernel/cpu/resctrl/internal.h
>> @@ -373,6 +373,8 @@ struct arch_mbm_state {
>> * @ctrl_val: array of cache or mem ctrl values (indexed by CLOSID)
>> * @arch_mbm_total: arch private state for MBM total bandwidth
>> * @arch_mbm_local: arch private state for MBM local bandwidth
>> + * @mbm_total_cfg: MBM total bandwidth configuration
>> + * @mbm_local_cfg: MBM local bandwidth configuration
>> *
>> * Members of this structure are accessed via helpers that provide
>> abstraction.
>> */
>> @@ -381,6 +383,8 @@ struct rdt_hw_domain {
>> u32 *ctrl_val;
>> struct arch_mbm_state *arch_mbm_total;
>> struct arch_mbm_state *arch_mbm_local;
>> + u32 mbm_total_cfg;
>> + u32 mbm_local_cfg;
>> };
>
> Similar to the abmc_enabled member of rdt_hw_resource, these new
> members of rdt_hw_domain are architecture specific and should never be
> touched directly by resctrl fs code, for example, from mbm_config_show().
Yes. Understood. Will check all the accesses.
>
>> static inline struct rdt_hw_domain *resctrl_to_arch_dom(struct
>> rdt_domain *r)
>> @@ -622,6 +626,7 @@ void __check_limbo(struct rdt_domain *d, bool
>> force_free);
>> void rdt_domain_reconfigure_cdp(struct rdt_resource *r);
>> void __init resctrl_file_fflags_init(const char *config,
>> unsigned long fflags);
>> +void arch_domain_mbm_evt_config(struct rdt_hw_domain *hw_dom);
>> void rdt_staged_configs_clear(void);
>> bool closid_allocated(unsigned int closid);
>> int resctrl_find_cleanest_closid(void);
>> diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c
>> b/arch/x86/kernel/cpu/resctrl/monitor.c
>> index b1d002e5e93d..ab0f4bb49bd9 100644
>> --- a/arch/x86/kernel/cpu/resctrl/monitor.c
>> +++ b/arch/x86/kernel/cpu/resctrl/monitor.c
>> @@ -1093,6 +1093,27 @@ int __init rdt_get_mon_l3_config(struct
>> rdt_resource *r)
>> return 0;
>> }
>> +void arch_domain_mbm_evt_config(struct rdt_hw_domain *hw_dom)
>> +{
>> + u64 msrval;
>> +
>> + /*
>> + * Read the configuration registers QOS_EVT_CFG_n, where <n> is
>> + * the BMEC event number (EvtID).
>> + * 0 for evtid == QOS_L3_MBM_TOTAL_EVENT_ID
>> + * 1 for evtid == QOS_L3_MBM_LOCAL_EVENT_ID
>
> This is what mon_event_config_index_get() is for, no?
Yes, it is. I can change it.
>
>> + */
>> + if (mbm_total_event.configurable) {
>> + rdmsrl(MSR_IA32_EVT_CFG_BASE, msrval);
>> + hw_dom->mbm_total_cfg = msrval & MAX_EVT_CONFIG_BITS;
>> + }
>> +
>> + if (mbm_local_event.configurable) {
>> + rdmsrl(MSR_IA32_EVT_CFG_BASE + 1, msrval);
>> + hw_dom->mbm_local_cfg = msrval & MAX_EVT_CONFIG_BITS;
>> + }
>> +}
>> +
>> void __exit rdt_put_mon_l3_config(void)
>> {
>> dom_data_exit();
>
> Reinette
>
--
Thanks
Babu Moger
