From 4eb6486cb43c93382c27a2659ba978c660e98498 Mon Sep 17 00:00:00 2001
From: Marc Zyngier <maz@kernel.org>
Date: Mon, 26 Sep 2022 15:51:19 +0100
Subject: [PATCH] KVM: selftests: dirty-log: Upgrade flag accesses to
acquire/release semantics
In order to preserve ordering, make sure that the flag accesses
in the dirty log are done using acquire/release accessors.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Link: https://lore.kernel.org/r/20220926145120.27974-6-maz@kernel.org
---
tools/testing/selftests/kvm/dirty_log_test.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/kvm/dirty_log_test.c b/tools/testing/selftests/kvm/dirty_log_test.c
index 9c883c94d478f..53627add8a7cb 100644
--- a/tools/testing/selftests/kvm/dirty_log_test.c
+++ b/tools/testing/selftests/kvm/dirty_log_test.c
@@ -17,6 +17,7 @@
#include <linux/bitmap.h>
#include <linux/bitops.h>
#include <linux/atomic.h>
+#include <asm/barrier.h>
#include "kvm_util.h"
#include "test_util.h"
@@ -279,12 +280,12 @@ static void dirty_ring_create_vm_done(struct kvm_vm *vm)
static inline bool dirty_gfn_is_dirtied(struct kvm_dirty_gfn *gfn)
{
- return gfn->flags == KVM_DIRTY_GFN_F_DIRTY;
+ return smp_load_acquire(&gfn->flags) == KVM_DIRTY_GFN_F_DIRTY;
}
static inline void dirty_gfn_set_collected(struct kvm_dirty_gfn *gfn)
{
- gfn->flags = KVM_DIRTY_GFN_F_RESET;
+ smp_store_release(&gfn->flags, KVM_DIRTY_GFN_F_RESET);
}
static uint32_t dirty_ring_collect_one(struct kvm_dirty_gfn *dirty_gfns,
--
2.30.2