KVM: selftests: dirty-log: Use KVM_CAP_DIRTY_LOG_RING_ACQ_REL if available

Pick KVM_CAP_DIRTY_LOG_RING_ACQ_REL if exposed by the kernel.
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/20220926145120.27974-7-maz@kernel.org

tools/testing/selftests/kvm/dirty_log_test.c

@@ -265,7 +265,8 @@ static void default_after_vcpu_run(struct kvm_vcpu *vcpu, int ret, int err)
 
 static bool dirty_ring_supported(void)
 {
-	return kvm_has_cap(KVM_CAP_DIRTY_LOG_RING);
+	return (kvm_has_cap(KVM_CAP_DIRTY_LOG_RING) ||
+		kvm_has_cap(KVM_CAP_DIRTY_LOG_RING_ACQ_REL));
 }
 
 static void dirty_ring_create_vm_done(struct kvm_vm *vm)

tools/testing/selftests/kvm/lib/kvm_util.c

@@ -82,7 +82,10 @@ unsigned int kvm_check_cap(long cap)
 
 void vm_enable_dirty_ring(struct kvm_vm *vm, uint32_t ring_size)
 {
-	vm_enable_cap(vm, KVM_CAP_DIRTY_LOG_RING, ring_size);
+	if (vm_check_cap(vm, KVM_CAP_DIRTY_LOG_RING_ACQ_REL))
+		vm_enable_cap(vm, KVM_CAP_DIRTY_LOG_RING_ACQ_REL, ring_size);
+	else
+		vm_enable_cap(vm, KVM_CAP_DIRTY_LOG_RING, ring_size);
 	vm->dirty_ring_size = ring_size;
 }