The following commit has been merged into the x86/urgent branch of tip:
Commit-ID: a547a5880cba6f287179135381f1b484b251be31
Gitweb: https://git.kernel.org/tip/a547a5880cba6f287179135381f1b484b251be31
Author: Peter Newman <peternewman@xxxxxxxxxx>
AuthorDate: Thu, 22 Aug 2024 12:02:11 -07:00
Committer: Borislav Petkov (AMD) <bp@xxxxxxxxx>
CommitterDate: Wed, 28 Aug 2024 11:13:08 +02:00
x86/resctrl: Fix arch_mbm_* array overrun on SNC
When using resctrl on systems with Sub-NUMA Clustering enabled, monitoring
groups may be allocated RMID values which would overrun the
arch_mbm_{local,total} arrays.
This is due to inconsistencies in whether the SNC-adjusted num_rmid value or
the unadjusted value in resctrl_arch_system_num_rmid_idx() is used. The
num_rmid value for the L3 resource is currently:
resctrl_arch_system_num_rmid_idx() / snc_nodes_per_l3_cache
As a simple fix, make resctrl_arch_system_num_rmid_idx() return the
SNC-adjusted, L3 num_rmid value on x86.
Fixes: e13db55b5a0d ("x86/resctrl: Introduce snc_nodes_per_l3_cache")
Signed-off-by: Peter Newman <peternewman@xxxxxxxxxx>
Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Reviewed-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
Link: https://lore.kernel.org/r/20240822190212.1848788-1-peternewman@xxxxxxxxxx
---
arch/x86/include/asm/resctrl.h | 6 ------
arch/x86/kernel/cpu/resctrl/core.c | 8 ++++++++
include/linux/resctrl.h | 1 +
3 files changed, 9 insertions(+), 6 deletions(-)
diff --git a/arch/x86/include/asm/resctrl.h b/arch/x86/include/asm/resctrl.h
index 12dbd25..8b1b6ce 100644
--- a/arch/x86/include/asm/resctrl.h
+++ b/arch/x86/include/asm/resctrl.h
@@ -156,12 +156,6 @@ static inline void resctrl_sched_in(struct task_struct *tsk)
__resctrl_sched_in(tsk);
}
-static inline u32 resctrl_arch_system_num_rmid_idx(void)
-{
- /* RMID are independent numbers for x86. num_rmid_idx == num_rmid */
- return boot_cpu_data.x86_cache_max_rmid + 1;
-}
-
static inline void resctrl_arch_rmid_idx_decode(u32 idx, u32 *closid, u32 *rmid)
{
*rmid = idx;
diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index 1930fce..8591d53 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -119,6 +119,14 @@ struct rdt_hw_resource rdt_resources_all[] = {
},
};
+u32 resctrl_arch_system_num_rmid_idx(void)
+{
+ struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl;
+
+ /* RMID are independent numbers for x86. num_rmid_idx == num_rmid */
+ return r->num_rmid;
+}
+
/*
* cache_alloc_hsw_probe() - Have to probe for Intel haswell server CPUs
* as they do not have CPUID enumeration support for Cache allocation.
diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
index b0875b9..d94abba 100644
--- a/include/linux/resctrl.h
+++ b/include/linux/resctrl.h
@@ -248,6 +248,7 @@ struct resctrl_schema {
/* The number of closid supported by this resource regardless of CDP */
u32 resctrl_arch_get_num_closid(struct rdt_resource *r);
+u32 resctrl_arch_system_num_rmid_idx(void);
int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid);
/*
|