x86/intel_rdt: Do not allow pseudo-locking of MBA resource

A system supporting pseudo-locking may have MBA as well as CAT
resources of which only the CAT resources could support cache
pseudo-locking. When the schemata to be pseudo-locked is provided it
should be checked that that schemata does not attempt to pseudo-lock a
MBA resource.

Fixes: e0bdfe8e3 ("x86/intel_rdt: Support creation/removal of pseudo-locked region")
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "H Peter Anvin" <hpa@zytor.com>
Cc: "Tony Luck" <tony.luck@intel.com>
Cc: "Xiaochen Shen" <xiaochen.shen@intel.com>
Cc: "Chen Yu" <yu.c.chen@intel.com>
Link: https://lkml.kernel.org/r/1537048707-76280-7-git-send-email-fenghua.yu@intel.com

diff --git a/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c b/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
index edd5761..0f53049 100644 (file)
--- a/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
+++ b/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
@@ -195,6 +195,12 @@ static int parse_line(char *line, struct rdt_resource *r,
        struct rdt_domain *d;
        unsigned long dom_id;
 
+       if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP &&
+           r->rid == RDT_RESOURCE_MBA) {
+               rdt_last_cmd_puts("Cannot pseudo-lock MBA resource\n");
+               return -EINVAL;
+       }
+
 next:
        if (!line || line[0] == '\0')
                return 0;