[PATCH 4.19 90/90] x86/resctrl: Dont stop walking closids when a locksetup group is found

From: Greg Kroah-Hartman
Date: Mon Jun 24 2019 - 06:06:53 EST

From: James Morse <james.morse@xxxxxxx>

commit 87d3aa28f345bea77c396855fa5d5fec4c24461f upstream.

When a new control group is created __init_one_rdt_domain() walks all
the other closids to calculate the sets of used and unused bits.

If it discovers a pseudo_locksetup group, it breaks out of the loop. This
means any later closid doesn't get its used bits added to used_b. These
bits will then get set in unused_b, and added to the new control group's
configuration, even if they were marked as exclusive for a later closid.

When encountering a pseudo_locksetup group, we should continue. This is
because "a resource group enters 'pseudo-locked' mode after the schemata is
written while the resource group is in 'pseudo-locksetup' mode." When we
find a pseudo_locksetup group, its configuration is expected to be
overwritten, we can skip it.

Fixes: dfe9674b04ff6 ("x86/intel_rdt: Enable entering of pseudo-locksetup mode")
Signed-off-by: James Morse <james.morse@xxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Acked-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: H Peter Avin <hpa@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/20190603172531.178830-1-james.morse@xxxxxxx
[Dropped comment due to lack of space]
Signed-off-by: James Morse <james.morse@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -2379,7 +2379,7 @@ static int rdtgroup_init_alloc(struct rd
if (closid_allocated(i) && i != closid) {
mode = rdtgroup_mode_by_closid(i);
- break;
+ continue;
used_b |= *ctrl;
d->new_ctrl |= *ctrl;