Hi Babu,
On 7/16/24 8:13 AM, Moger, Babu wrote:
On 7/12/24 17:05, Reinette Chatre wrote:
On 7/3/24 2:48 PM, Babu Moger wrote:
Add the functionality to enable/disable AMD ABMC feature.
AMD ABMC feature is enabled by setting enabled bit(0) in MSR
L3_QOS_EXT_CFG. When the state of ABMC is changed, the MSR needs
to be updated on all the logical processors in the QOS Domain.
Hardware counters will reset when ABMC state is changed. Reset the
architectural state so that reading of hardware counter is not considered
as an overflow in next update.
The ABMC 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).
Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537
---
v5: Renamed resctrl_abmc_enable to resctrl_arch_abmc_enable.
Renamed resctrl_abmc_disable to resctrl_arch_abmc_disable.
Introduced resctrl_arch_get_abmc_enabled to get abmc state from
non-arch code.
Renamed resctrl_abmc_set_all to _resctrl_abmc_enable().
Modified commit log to make it clear about AMD ABMC feature.
v3: No changes.
v2: Few text changes in commit message.
---
arch/x86/include/asm/msr-index.h | 1 +
arch/x86/kernel/cpu/resctrl/internal.h | 13 +++++
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 66 ++++++++++++++++++++++++++
3 files changed, 80 insertions(+)
diff --git a/arch/x86/include/asm/msr-index.h
b/arch/x86/include/asm/msr-index.h
index 01342963011e..263b2d9d00ed 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -1174,6 +1174,7 @@
#define MSR_IA32_MBA_BW_BASE 0xc0000200
#define MSR_IA32_SMBA_BW_BASE 0xc0000280
#define MSR_IA32_EVT_CFG_BASE 0xc0000400
+#define MSR_IA32_L3_QOS_EXT_CFG 0xc00003ff
/* 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 2bd207624eec..0ce9797f80fe 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -97,6 +97,9 @@ cpumask_any_housekeeping(const struct cpumask *mask,
int exclude_cpu)
return cpu;
}
+/* Setting bit 0 in L3_QOS_EXT_CFG enables the ABMC feature */
Please be consistent throughout series to have sentences end with period.
Sure.
+#define ABMC_ENABLE BIT(0)
+
struct rdt_fs_context {
struct kernfs_fs_context kfc;
bool enable_cdpl2;
@@ -477,6 +480,7 @@ struct rdt_parse_data {
* @mbm_cfg_mask: Bandwidth sources that can be tracked when Bandwidth
* Monitoring Event Configuration (BMEC) is supported.
* @cdp_enabled: CDP state of this resource
+ * @abmc_enabled: ABMC feature is enabled
*
* Members of this structure are either private to the architecture
* e.g. mbm_width, or accessed via helpers that provide abstraction. e.g.
@@ -491,6 +495,7 @@ struct rdt_hw_resource {
unsigned int mbm_width;
unsigned int mbm_cfg_mask;
bool cdp_enabled;
+ bool abmc_enabled;
};
mbm_cntr_enabled? This is architecture specific code so there is more
flexibility
here, but it may make implementation easier to understand if consistent
naming is used
between fs and arch code.
How about "mbm_cntr_assign_enabled" or "cntr_assign_enabled" ?
My preference is to keep the term "mbm_cntr" to be consistent with the
other variables/struct members to help when reading the code.
"mbm_cntr_assign_enabled" does seem to be getting long though.
Are you planning to use it by assigning it to a local variable with shorter
name?
As a sidenote, I will be offline for large portions of the next few weeks
and thus unresponsive during this time. I'll be back to a regular
schedule on August 12th.
Reinette
