From 939b90b20bc87e199b6b53942764b987289b87ce Mon Sep 17 00:00:00 2001 From: Reinette Chatre Date: Sat, 15 Sep 2018 14:58:26 -0700 Subject: [PATCH] x86/intel_rdt: Fix exclusive mode handling of MBA resource It is possible for a resource group to consist out of MBA as well as CAT/CDP resources. The "exclusive" resource mode only applies to the CAT/CDP resources since MBA allocations cannot be specified to overlap or not. When a user requests a resource group to become "exclusive" then it can only be successful if there are CAT/CDP resources in the group and none of their CBMs associated with the group's CLOSID overlaps with any other resource group. Fix the "exclusive" mode setting by failing if there isn't any CAT/CDP resource in the group and ensuring that the CBM checking is only done on CAT/CDP resources. Fixes: 49f7b4efa ("x86/intel_rdt: Enable setting of exclusive mode") Signed-off-by: Reinette Chatre Signed-off-by: Fenghua Yu Signed-off-by: Thomas Gleixner Cc: "H Peter Anvin" Cc: "Tony Luck" Cc: "Xiaochen Shen" Cc: "Chen Yu" Link: https://lkml.kernel.org/r/1537048707-76280-9-git-send-email-fenghua.yu@intel.com --- arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c index afd93d45e21b..f3231f78d69b 100644 --- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c +++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c @@ -1031,16 +1031,27 @@ static bool rdtgroup_mode_test_exclusive(struct rdtgroup *rdtgrp) { int closid = rdtgrp->closid; struct rdt_resource *r; + bool has_cache = false; struct rdt_domain *d; for_each_alloc_enabled_rdt_resource(r) { + if (r->rid == RDT_RESOURCE_MBA) + continue; + has_cache = true; list_for_each_entry(d, &r->domains, list) { if (rdtgroup_cbm_overlaps(r, d, d->ctrl_val[closid], - rdtgrp->closid, false)) + rdtgrp->closid, false)) { + rdt_last_cmd_puts("schemata overlaps\n"); return false; + } } } + if (!has_cache) { + rdt_last_cmd_puts("cannot be exclusive without CAT/CDP\n"); + return false; + } + return true; } @@ -1092,7 +1103,6 @@ static ssize_t rdtgroup_mode_write(struct kernfs_open_file *of, rdtgrp->mode = RDT_MODE_SHAREABLE; } else if (!strcmp(buf, "exclusive")) { if (!rdtgroup_mode_test_exclusive(rdtgrp)) { - rdt_last_cmd_printf("schemata overlaps\n"); ret = -EINVAL; goto out; } -- 2.39.5