x86/resctrl: Preserve CDP enable over CPU hotplug
Resctrl assumes that all CPUs are online when the filesystem is mounted,
and that CPUs remember their CDP-enabled state over CPU hotplug.
This goes wrong when resctrl's CDP-enabled state changes while all the
CPUs in a domain are offline.
When a domain comes online, enable (or disable!) CDP to match resctrl's
current setting.
Fixes: 5ff193fbde20 ("x86/intel_rdt: Add basic resctrl filesystem support")
Suggested-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20200221162105.154163-1-james.morse@arm.com
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 9d4e73a..5a359d9 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -1859,6 +1859,19 @@ static int set_cache_qos_cfg(int level, bool enable)
return 0;
}
+/* Restore the qos cfg state when a domain comes online */
+void rdt_domain_reconfigure_cdp(struct rdt_resource *r)
+{
+ if (!r->alloc_capable)
+ return;
+
+ if (r == &rdt_resources_all[RDT_RESOURCE_L2DATA])
+ l2_qos_cfg_update(&r->alloc_enabled);
+
+ if (r == &rdt_resources_all[RDT_RESOURCE_L3DATA])
+ l3_qos_cfg_update(&r->alloc_enabled);
+}
+
/*
* Enable or disable the MBA software controller
* which helps user specify bandwidth in MBps.
