Re: [PATCH v5 08/15] hw/riscv/virt.c: fix aclint soc/mtimer nodename

[Chao Liu <chao.liu@processmission.com>]

On Fri, Aug 28, 2026 at 05:39:10PM +0800, Daniel Henrique Barboza wrote:
> Running 'dtc' to generate a readable fdt for the virt machine produce
> warnings:
> 
>  $ dtc -I dtb -O dts virt.dtb > virt.dts
> <stdout>: Warning (simple_bus_reg): /soc/mtimer@2000000: simple-bus unit address format error, expected "2007ff8"
> <stdout>: Warning (simple_bus_reg): /soc/mtimer@2008000: simple-bus unit address format error, expected "200fff8"
> 
> This happens because the 'reg' field does not match the address in the
> nodename.  The right fix, pointed out by Chao in [1], is to make the
> nodename match the reg value:
> 
> "In the current QEMU implement, `addr` is the MTIMECMP base address,
> while the MTIME register is located at addr + RISCV_ACLINT_DEFAULT_MTIME."
> 
> In other words, the 'reg' value is correct but the nodename isn't.
> 
> We'll make the fix now, allowing the next patch to move the fixed version
> of aclint FDT to fdt-common.
> 
> [1] https://lore.kernel.org/qemu-devel/apHH1upnh8udUUT-@ChaodeMacBook-Pro.local/
> 
> Cc: qemu-stable@nongnu.org
> Suggested-by: Chao Liu <chao.liu@processmission.com>
> Fixes: 954886ea6d ("hw/riscv: virt: Add optional ACLINT support to virt machine")
> Signed-off-by: Daniel Henrique Barboza <daniel.barboza@oss.qualcomm.com>
Reviewed-by: Chao Liu <chao.liu@processmission.com>

Thanks,
Chao

> ---
>  hw/riscv/virt.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c
> index a6ec9def16..83a4b7710d 100644
> --- a/hw/riscv/virt.c
> +++ b/hw/riscv/virt.c
> @@ -234,7 +234,8 @@ static void create_fdt_socket_aclint(RISCVVirtState *s,
>                 (s->memmap[VIRT_CLINT].size * socket);
>          size = s->memmap[VIRT_CLINT].size - RISCV_ACLINT_SWI_SIZE;
>      }
> -    name = g_strdup_printf("/soc/mtimer@%lx", addr);
> +    name = g_strdup_printf("/soc/mtimer@%"HWADDR_PRIx,
> +                           addr + RISCV_ACLINT_DEFAULT_MTIME);
>      qemu_fdt_add_subnode(ms->fdt, name);
>      qemu_fdt_setprop_string(ms->fdt, name, "compatible",
>          "riscv,aclint-mtimer");
> -- 
> 2.43.0
>