diff --git a/lib/igt_kms.c b/lib/igt_kms.c
index aae32202..85dc0aa8 100644
--- a/lib/igt_kms.c
+++ b/lib/igt_kms.c
@@ -1560,6 +1560,17 @@ static void igt_display_log_shift(igt_display_t *display, int shift)
 	igt_assert(display->log_shift >= 0);
 }
 
+static int igt_output_idx(igt_output_t *output)
+{
+	int i;
+
+	for (i = 0; i < output->display->n_outputs; i++)
+		if (&output->display->outputs[i] == output)
+			return i;
+
+	return -1;
+}
+
 static void igt_output_refresh(igt_output_t *output)
 {
 	igt_display_t *display = output->display;
@@ -1990,40 +2001,6 @@ void igt_display_fini(igt_display_t *display)
 	display->pipes = NULL;
 }
 
-static void igt_display_refresh(igt_display_t *display)
-{
-	igt_output_t *output;
-	int i;
-
-	unsigned long pipes_in_use = 0;
-
-       /* Check that two outputs aren't trying to use the same pipe */
-	for (i = 0; i < display->n_outputs; i++) {
-		output = &display->outputs[i];
-
-		if (pipes_in_use & output->pending_crtc_idx_mask)
-			goto report_dup;
-
-		pipes_in_use |= output->pending_crtc_idx_mask;
-
-		if (output->force_reprobe)
-			igt_output_refresh(output);
-	}
-
-	return;
-
-report_dup:
-	for (; i > 0; i--) {
-		igt_output_t *b = &display->outputs[i - 1];
-
-		igt_assert_f(output->pending_crtc_idx_mask !=
-			     b->pending_crtc_idx_mask,
-			     "%s and %s are both trying to use pipe %s\n",
-			     igt_output_name(output), igt_output_name(b),
-			     kmstest_pipe_name(ffs(b->pending_crtc_idx_mask) - 1));
-	}
-}
-
 static igt_pipe_t *igt_output_get_driving_pipe(igt_output_t *output)
 {
 	igt_display_t *display = output->display;
@@ -2047,6 +2024,38 @@ static igt_pipe_t *igt_output_get_driving_pipe(igt_output_t *output)
 	return &display->pipes[pipe];
 }
 
+static void igt_display_refresh(igt_display_t *display)
+{
+	igt_output_t *output;
+	igt_pipe_t *pipe;
+	int i;
+
+	unsigned long pipes_in_use = 0;
+
+	/* Check that outputs and pipes agree wrt. cloning */
+	for (i = 0; i < display->n_outputs; i++) {
+		output = &display->outputs[i];
+
+		pipe = igt_output_get_driving_pipe(output);
+		if (pipe) {
+			igt_assert_f(pipe->outputs & (1 << igt_output_idx(output)),
+				     "Output %s not expected to be using pipe %s\n",
+				     igt_output_name(output),
+				     kmstest_pipe_name(pipe->pipe));
+
+			if (pipes_in_use & output->pending_crtc_idx_mask)
+				LOG(display, "Output %s clones pipe %s\n",
+				    igt_output_name(output),
+				    kmstest_pipe_name(pipe->pipe));
+		}
+
+		pipes_in_use |= output->pending_crtc_idx_mask;
+
+		if (output->force_reprobe)
+			igt_output_refresh(output);
+	}
+}
+
 static igt_plane_t *igt_pipe_get_plane(igt_pipe_t *pipe, int plane_idx)
 {
 	igt_assert_f(plane_idx >= 0 && plane_idx < pipe->n_planes,
@@ -2941,6 +2950,16 @@ void igt_output_override_mode(igt_output_t *output, drmModeModeInfo *mode)
 		pipe->mode_changed = true;
 }
 
+void igt_output_clone_pipe(igt_output_t *output, enum pipe pipe)
+{
+	igt_display_t *display = output->display;
+	uint32_t current_clones = display->pipes[pipe].outputs;
+
+	igt_output_set_pipe(output, pipe);
+
+	display->pipes[pipe].outputs |= current_clones;
+}
+
 void igt_output_set_pipe(igt_output_t *output, enum pipe pipe)
 {
 	igt_display_t *display = output->display;
@@ -2952,6 +2971,7 @@ void igt_output_set_pipe(igt_output_t *output, enum pipe pipe)
 		old_pipe = igt_output_get_driving_pipe(output);
 
 		old_pipe->mode_changed = true;
+		old_pipe->outputs &= ~(1 << igt_output_idx(output));
 	}
 
 	if (pipe == PIPE_NONE) {
@@ -2963,6 +2983,8 @@ void igt_output_set_pipe(igt_output_t *output, enum pipe pipe)
 		output->pending_crtc_idx_mask = 1 << pipe;
 
 		display->pipes[pipe].mode_changed = true;
+
+		display->pipes[pipe].outputs = (1 << igt_output_idx(output));
 	}
 
 	output->config.pipe_changed = true;
diff --git a/lib/igt_kms.h b/lib/igt_kms.h
index ab8ec764..9ddcfade 100644
--- a/lib/igt_kms.h
+++ b/lib/igt_kms.h
@@ -358,6 +358,8 @@ struct igt_pipe {
 
 	int32_t out_fence_fd;
 	bool out_fence_requested;
+
+	uint32_t outputs;
 };
 
 typedef struct {
@@ -402,6 +404,7 @@ const char *igt_output_name(igt_output_t *output);
 drmModeModeInfo *igt_output_get_mode(igt_output_t *output);
 void igt_output_override_mode(igt_output_t *output, drmModeModeInfo *mode);
 void igt_output_set_pipe(igt_output_t *output, enum pipe pipe);
+void igt_output_clone_pipe(igt_output_t *output, enum pipe pipe);
 void igt_output_set_scaling_mode(igt_output_t *output, uint64_t scaling_mode);
 
 igt_plane_t *igt_output_get_plane(igt_output_t *output, int plane_idx);
