@@ -250,6 +250,12 @@
*/
#define LIBXL_HAVE_DEVICETREE_PASSTHROUGH 1
+#if defined(__arm__) || defined(__aarch64__)
+/**
+ * This means Device Tree Overlay is supported.
+ */
+#define LIBXL_HAVE_DT_OVERLAY 1
+#endif
/*
* libxl_domain_build_info has device_model_user to specify the user to
* run the device model with. See docs/misc/qemu-deprivilege.txt.
@@ -2453,6 +2459,11 @@ libxl_device_pci *libxl_device_pci_list(libxl_ctx *ctx, uint32_t domid,
int *num);
void libxl_device_pci_list_free(libxl_device_pci* list, int num);
+#if defined(__arm__) || defined(__aarch64__)
+int libxl_dt_overlay(libxl_ctx *ctx, void *overlay,
+ uint32_t overlay_size, uint8_t overlay_op);
+#endif
+
/*
* Turns the current process into a backend device service daemon
* for a driver domain.
@@ -112,6 +112,9 @@ OBJS-y += _libxl_types.o
OBJS-y += libxl_flask.o
OBJS-y += _libxl_types_internal.o
+# Device tree overlay is enabled only for ARM architecture.
+OBJS-$(CONFIG_ARM) += libxl_dt_overlay.o
+
ifeq ($(CONFIG_LIBNL),y)
CFLAGS_LIBXL += $(LIBNL3_CFLAGS)
endif
new file mode 100644
@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2021 Xilinx Inc.
+ * Author Vikram Garhwal <fnu.vikram@xilinx.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation; version 2.1 only. with the special
+ * exception on linking described in file LICENSE.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ */
+
+#include "libxl_osdeps.h" /* must come before any other headers */
+#include "libxl_internal.h"
+#include <libfdt.h>
+#include <xenctrl.h>
+
+static int check_overlay_fdt(libxl__gc *gc, void *fdt, size_t size)
+{
+ int r;
+
+ if (fdt_magic(fdt) != FDT_MAGIC) {
+ LOG(ERROR, "Overlay FDT is not a valid Flat Device Tree");
+ return ERROR_FAIL;
+ }
+
+ r = fdt_check_header(fdt);
+ if (r) {
+ LOG(ERROR, "Failed to check the overlay FDT (%d)", r);
+ return ERROR_FAIL;
+ }
+
+ if (fdt_totalsize(fdt) > size) {
+ LOG(ERROR, "Overlay FDT totalsize is too big");
+ return ERROR_FAIL;
+ }
+
+ return 0;
+}
+
+int libxl_dt_overlay(libxl_ctx *ctx, void *overlay_dt, uint32_t overlay_dt_size,
+ uint8_t overlay_op)
+{
+ int rc;
+ int r;
+ GC_INIT(ctx);
+
+ if (check_overlay_fdt(gc, overlay_dt, overlay_dt_size)) {
+ LOG(ERROR, "Overlay DTB check failed");
+ rc = ERROR_FAIL;
+ goto out;
+ } else {
+ LOG(DEBUG, "Overlay DTB check passed");
+ rc = 0;
+ }
+
+ r = xc_dt_overlay(ctx->xch, overlay_dt, overlay_dt_size, overlay_op);
+
+ if (r) {
+ LOG(ERROR, "%s: Adding/Removing overlay dtb failed.", __func__);
+ rc = ERROR_FAIL;
+ }
+
+out:
+ GC_FREE;
+ return rc;
+}
+