[Qemu-devel] [PATCH 2/2] hw/arm/virt: Silence dtc /memory warning

[Eric Auger <eric.auger@redhat.com>]

When running dtc on the guest /proc/device-tree we get the
following warning: Warning (unit_address_vs_reg): Node /memory
has a reg or ranges property, but no unit name".

Let's fix that by adding the unit address to the node name. We also
don't create the /memory node anymore in create_fdt(). We directly
create it in load_dtb. /chosen still needs to be created in create_fdt
as the uart needs it. In case the user provided his own dtb, either
the bank is added to the existing /memory node or if this latter is
not found we create a new separate memory node.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
---
 hw/arm/boot.c | 20 ++++++++++++++------
 hw/arm/virt.c |  6 ------
 2 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/hw/arm/boot.c b/hw/arm/boot.c
index 1e2be20..2054670 100644
--- a/hw/arm/boot.c
+++ b/hw/arm/boot.c
@@ -593,24 +593,32 @@ static int load_dtb(hwaddr addr, const struct arm_boot_info *binfo,
             g_free(nodename);
         }
     } else {
+        char *nodename = g_strdup("/memory");
         Error *err = NULL;
 
-        rc = fdt_path_offset(fdt, "/memory");
+        /* If there is an existing /memory node (user provided dtb), we add the
+         * new bank into it, otherwise we create a /memory@addr node
+         */
+        rc = fdt_path_offset(fdt, nodename);
         if (rc < 0) {
-            qemu_fdt_add_subnode(fdt, "/memory");
+            g_free(nodename);
+            nodename = g_strdup_printf("/memory@%" PRIx64, binfo->loader_start);
+
+            qemu_fdt_add_subnode(fdt, nodename);
         }
 
-        if (!qemu_fdt_getprop(fdt, "/memory", "device_type", NULL, &err)) {
-            qemu_fdt_setprop_string(fdt, "/memory", "device_type", "memory");
+        if (!qemu_fdt_getprop(fdt, nodename, "device_type", NULL, &err)) {
+            qemu_fdt_setprop_string(fdt, nodename, "device_type", "memory");
         }
 
-        rc = qemu_fdt_setprop_sized_cells(fdt, "/memory", "reg",
+        rc = qemu_fdt_setprop_sized_cells(fdt, nodename, "reg",
                                           acells, binfo->loader_start,
                                           scells, binfo->ram_size);
         if (rc < 0) {
-            fprintf(stderr, "couldn't set /memory/reg\n");
+            fprintf(stderr, "couldn't set %s reg\n", nodename);
             goto fail;
         }
+        g_free(nodename);
     }
 
     rc = fdt_path_offset(fdt, "/chosen");
diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index b1e9a6b..46c5c3f 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -203,13 +203,7 @@ static void create_fdt(VirtMachineState *vms)
     qemu_fdt_setprop_cell(fdt, "/", "#address-cells", 0x2);
     qemu_fdt_setprop_cell(fdt, "/", "#size-cells", 0x2);
 
-    /*
-     * /chosen and /memory nodes must exist for load_dtb
-     * to fill in necessary properties later
-     */
     qemu_fdt_add_subnode(fdt, "/chosen");
-    qemu_fdt_add_subnode(fdt, "/memory");
-    qemu_fdt_setprop_string(fdt, "/memory", "device_type", "memory");
 
     /* Clock node, for the benefit of the UART. The kernel device tree
      * binding documentation claims the PL011 node clock properties are
-- 
2.5.5