The KVM_DIRTY_GFN_F_DIRTY flag ensures that the entry is valid. If the read of the fields are not ordered after the read of the flag, QEMU might see stale values.
Cc: Peter Xu <pet...@redhat.com> Cc: Gavin Shan <gs...@redhat.com> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> --- accel/kvm/kvm-all.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c index 8d81ab74de..f49643cd24 100644 --- a/accel/kvm/kvm-all.c +++ b/accel/kvm/kvm-all.c @@ -719,7 +719,7 @@ static void kvm_dirty_ring_mark_page(KVMState *s, uint32_t as_id, static bool dirty_gfn_is_dirtied(struct kvm_dirty_gfn *gfn) { - return gfn->flags == KVM_DIRTY_GFN_F_DIRTY; + return qatomic_load_acquire(&gfn->flags, KVM_DIRTY_GFN_F_DIRTY); } static void dirty_gfn_set_collected(struct kvm_dirty_gfn *gfn) -- 2.37.1