Re: [PATCH v15 08/34] x86,fs/resctrl: Detect Assignable Bandwidth Monitoring feature details

["Moger, Babu" <babu.moger@amd.com>]

Hi Reinette,

On 7/15/25 11:26, Reinette Chatre wrote:
> Hi Babu,
> 
> On 7/8/25 3:17 PM, Babu Moger wrote:
>> ABMC feature details are reported via CPUID Fn8000_0020_EBX_x5.
>> Bits Description
>> 15:0 MAX_ABMC Maximum Supported Assignable Bandwidth
>>      Monitoring Counter ID + 1
>>
>> The feature details are documented in 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).
>>
>> Detect the feature and number of assignable counters supported. Also,
>> enable QOS_L3_MBM_TOTAL_EVENT_ID and QOS_L3_MBM_LOCAL_EVENT_ID upon
>> detecting the ABMC feature. The current expectation is to support
>> these two events by default when ABMC is enabled.
>>
> 
> Did the right patches make it out as part of this submission? The above
> changelog contains text that was removed per
> https://lore.kernel.org/lkml/aca368e0-0936-4852-9cf6-688931e0c65d@amd.com/

Yes. Code changes are taken care.

v15: Minor update to changelog.
     Added check in resctrl_cpu_detect().
     Moved the resctrl_enable_mon_event() to resctrl_mon_resource_init().


But missed the changelog. Sorry about that.


Here is the updated version.
--------------------------------

x86,fs/resctrl: Detect Assignable Bandwidth Monitoring feature details

ABMC feature details are reported via CPUID Fn8000_0020_EBX_x5.
Bits Description
15:0 MAX_ABMC Maximum Supported Assignable Bandwidth
     Monitoring Counter ID + 1

The feature details are documented in 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).

Detect the feature and number of assignable counters supported. For
backward compatibility, upon detecting the assignable counter feature,
enable the mbm_total_bytes and mbm_local_bytes events that users are
familiar with as part of original L3 MBM support.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537
Signed-off-by: Babu Moger <babu.moger@amd.com>

-- 
Thanks
Babu Moger