Re: [PATCH v9 15/26] x86/resctrl: Add data structures and definitions for ABMC assignment

From: Reinette Chatre
Date: Fri Nov 15 2024 - 19:35:43 EST


Hi Babu,

On 10/29/24 4:21 PM, 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 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>
> ---

Reviewed-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>

Reinette