Re: [PATCH v4 6/6] board: qemu: m68k: Create virtio mmio instances

[Kuan-Wei Chiu <visitorckw@gmail.com>]

On Mon, Apr 13, 2026 at 06:22:40PM +0900, Daniel Palmer wrote:
> So that you can use virtio network, block etc create the virtio mmio
> instances. There are 128 of these even if they are not all used, a
> single mmio base value is passed via bootinfo.
> 
> Signed-off-by: Daniel Palmer <daniel@thingy.jp>

Reviewed-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Tested-by: Kuan-Wei Chiu <visitorckw@gmail.com>

Regards,
Kuan-Wei

> ---
>  arch/m68k/Kconfig                     | 14 +++++----
>  board/emulation/qemu-m68k/qemu-m68k.c | 45 +++++++++++++++++++++++++++
>  2 files changed, 53 insertions(+), 6 deletions(-)
> 
> diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
> index 6ce8f577e3a1..20a112880c87 100644
> --- a/arch/m68k/Kconfig
> +++ b/arch/m68k/Kconfig
> @@ -195,12 +195,14 @@ config TARGET_STMARK2
>          select M54418
>  
>  config TARGET_QEMU_M68K
> -    bool "Support QEMU m68k virt"
> -    select M68040
> -    imply CMD_DM
> -    help
> -      This target supports the QEMU m68k virtual machine (-M virt).
> -      It simulates a Motorola 68040 CPU with Goldfish peripherals.
> +	bool "Support QEMU m68k virt"
> +	select M68040
> +	select BOARD_EARLY_INIT_R
> +	select VIRTIO_MMIO
> +	imply CMD_DM
> +	help
> +	  This target supports the QEMU m68k virtual machine (-M virt).
> +	  It simulates a Motorola 68040 CPU with Goldfish peripherals.
>  
>  endchoice
>  
> diff --git a/board/emulation/qemu-m68k/qemu-m68k.c b/board/emulation/qemu-m68k/qemu-m68k.c
> index d3527aee1128..a19b23a28ce3 100644
> --- a/board/emulation/qemu-m68k/qemu-m68k.c
> +++ b/board/emulation/qemu-m68k/qemu-m68k.c
> @@ -14,9 +14,14 @@
>  #include <asm/bootinfo.h>
>  #include <asm/global_data.h>
>  #include <asm/io.h>
> +#include <dm.h>
> +#include <dm/device-internal.h>
> +#include <dm/lists.h>
>  #include <dm/platdata.h>
> +#include <dm/root.h>
>  #include <linux/errno.h>
>  #include <linux/sizes.h>
> +#include <virtio_mmio.h>
>  
>  DECLARE_GLOBAL_DATA_PTR;
>  
> @@ -25,6 +30,38 @@ static struct goldfish_rtc_plat rtc_plat;
>  static struct goldfish_timer_plat timer_plat;
>  static struct qemu_virt_ctrl_plat reset_plat;
>  
> +#define VIRTIO_MMIO_NUM	128
> +#define VIRTIO_MMIO_SZ	0x200
> +
> +static struct virtio_mmio_plat virtio_mmio_plat[VIRTIO_MMIO_NUM];
> +static char virtio_mmio_names[VIRTIO_MMIO_NUM][11];
> +static phys_addr_t virtio_mmio_base;
> +
> +static int create_virtio_mmios(void)
> +{
> +	struct driver *drv;
> +	int i, ret;
> +
> +	if (!virtio_mmio_base)
> +		return -ENODEV;
> +
> +	drv = lists_driver_lookup_name("virtio-mmio");
> +	if (!drv)
> +		return -ENOENT;
> +
> +	for (i = 0; i < VIRTIO_MMIO_NUM; i++) {
> +		virtio_mmio_plat[i].base = virtio_mmio_base + (VIRTIO_MMIO_SZ * i);
> +		sprintf(virtio_mmio_names[i], "virtio-%d", i);
> +
> +		ret = device_bind(dm_root(), drv, virtio_mmio_names[i],
> +				  &virtio_mmio_plat[i], ofnode_null(), NULL);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	return 0;
> +}
> +
>  /*
>   * Theoretical limit derivation:
>   * Max Bootinfo Size (Standard Page) = 4096 bytes
> @@ -65,6 +102,9 @@ static void parse_bootinfo(void)
>  		case BI_VIRT_CTRL_BASE:
>  			reset_plat.reg = base;
>  			break;
> +		case BI_VIRT_VIRTIO_BASE:
> +			virtio_mmio_base = base;
> +			break;
>  		case BI_MEMCHUNK:
>  			gd->ram_size = record->data[1];
>  			break;
> @@ -80,6 +120,11 @@ int board_early_init_f(void)
>  	return 0;
>  }
>  
> +int board_early_init_r(void)
> +{
> +	return create_virtio_mmios();
> +}
> +
>  int checkboard(void)
>  {
>  	puts("Board: QEMU m68k virt\n");
> -- 
> 2.51.0
>