Hi Babu,
This patch now only introduces one data structure so the subject could
be made more specific.
On 8/6/24 3:00 PM, Babu Moger wrote:
The ABMC feature provides an option to the user to assign a hardware
counter to an RMID 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.
(extra empty line)
The ABMC feature implements a pair of MSRs, L3_QOS_ABMC_CFG (C000_03FDh)
and L3_QOS_ABMC_DSC (C000_3FEh). The counters are configured by writing
to MSR L3_QOS_ABMC_CFG. Configuration is done by setting the counter id,
bandwidth source (RMID) and bandwidth configuration supported by BMEC
(Bandwidth Monitoring Event Configuration).
L3_QOS_ABMC_DSC is a read-only MSR. Reading L3_QOS_ABMC_DSC returns the
configuration of the counter id specified in L3_QOS_ABMC_CFG.cntr_id
with rmid(bw_src) and event configuration(bw_type).
Attempts to read or write these MSRs when ABMC is not enabled will result
in a #GP(0) exception.
Introduce data structures and definitions for ABMC MSRs.
MSR L3_QOS_ABMC_CFG (0xC000_03FDh) and L3_QOS_ABMC_DSC (0xC000_03FEh)
details.
The changelog and patch introduce L3_QOS_ABMC_DSC but I cannot see that it is
used in this series.
=========================================================================
Bits Mnemonic Description Access Reset
Type Value
=========================================================================
63 CfgEn Configuration Enable R/W 0
62 CtrEn Enable/disable Tracking 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
==========================================================================
Configuration and tracking:
CfgEn=1,CtrEn=0 : Configure CtrID and but no tracking the events yet.
CfgEn=1,CtrEn=1 : Configure CtrID and start tracking events.
Could you please add the above snippet noting field combinations to the
kernel-doc of the union?
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>
---
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 | 2 ++
arch/x86/kernel/cpu/resctrl/internal.h | 26 ++++++++++++++++++++++++++
2 files changed, 28 insertions(+)
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index d86469bf5d41..5b3931a59d5a 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -1183,6 +1183,8 @@
#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
+#define MSR_IA32_L3_QOS_ABMC_DSC 0xc00003fe
/* MSR_IA32_VMX_MISC bits */
#define MSR_IA32_VMX_MISC_INTEL_PT (1ULL << 14)
diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index 1021227d8c7e..af3efa35a62e 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -589,6 +589,32 @@ union cpuid_0x10_x_edx {
unsigned int full;
};
+/*
+ * ABMC counters can be configured by writing to L3_QOS_ABMC_CFG.
+ * @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 : Tracking enable bit.
+ * @cfg_en : Configuration enable bit.
+ */
+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;
+};
+
This data structure still uses tabs that seem to have goal of aligning members
but the tabs are used inconsistently and members are not lining up either.
void rdt_last_cmd_clear(void);
void rdt_last_cmd_puts(const char *s);
__printf(1, 2)
Reinette
