[PATCH 1/1] hw/riscv/virt.c: move create_fw_cfg() back to virt_machine_init()

[Daniel Henrique Barboza]

Commit 1c20d3ff6004 ("hw/riscv: virt: Add a machine done notifier")
moved the initialization of fw_cfg to the virt_machine_done() callback.

Problem is that the validation of fw_cfg by devices such as ramfb is
done before the machine done notifier is called. Moving create_fw_cfg()
to machine_done() results in QEMU failing to boot when using a ramfb
device:

./qemu-system-riscv64 -machine virt -device ramfb -serial stdio
qemu-system-riscv64: -device ramfb: ramfb device requires fw_cfg with DMA

The fix is simple: move create_fw_cfg() config back to
virt_machine_init(). This happens to be the same way the ARM 'virt'
machine deals with fw_cfg (see machvirt_init() and virt_machine_done()
in hw/arm/virt.c), so we're keeping consistency with how other machines
handle this device.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1343
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 hw/riscv/virt.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c
index e6d4f06e8d..4a11b4b010 100644
--- a/hw/riscv/virt.c
+++ b/hw/riscv/virt.c
@@ -1254,13 +1254,6 @@ static void virt_machine_done(Notifier *notifier, void 
*data)
     firmware_end_addr = riscv_find_and_load_firmware(machine, firmware_name,
                                                      start_addr, NULL);
 
-    /*
-     * Init fw_cfg.  Must be done before riscv_load_fdt, otherwise the device
-     * tree cannot be altered and we get FDT_ERR_NOSPACE.
-     */
-    s->fw_cfg = create_fw_cfg(machine);
-    rom_set_fw(s->fw_cfg);
-
     if (drive_get(IF_PFLASH, 0, 1)) {
         /*
          * S-mode FW like EDK2 will be kept in second plash (unit 1).
@@ -1468,6 +1461,13 @@ static void virt_machine_init(MachineState *machine)
     memory_region_add_subregion(system_memory, memmap[VIRT_MROM].base,
                                 mask_rom);
 
+    /*
+     * Init fw_cfg. Must be done before riscv_load_fdt, otherwise the
+     * device tree cannot be altered and we get FDT_ERR_NOSPACE.
+     */
+    s->fw_cfg = create_fw_cfg(machine);
+    rom_set_fw(s->fw_cfg);
+
     /* SiFive Test MMIO device */
     sifive_test_create(memmap[VIRT_TEST].base);
 
-- 
2.39.0