Re: [PATCH v2 3/4] hw/display/vga-mmio: QOM'ify vga_mmio_init() as TYPE_VGA_MMIO

[Thomas Huth]

On 06/12/2021 23.45, Philippe Mathieu-Daudé wrote:
> Introduce TYPE_VGA_MMIO, a sysbus device.
>
> While there is no change in the vga_mmio_init()
> interface, this is a migration compatibility break
> of the MIPS Acer Pica 61 Jazz machine (pica61).

It's unfortunate, but as far as I know, it would be pretty difficult or even 
impossible to get this done without versioned machine types? So IMHO it's ok 
to break this in this case here.

> Suggested-by: Thomas Huth <thuth@redhat.com>
> Reviewed-by: BALATON Zoltan <balaton@eik.bme.hu>
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
>   include/hw/display/vga.h |   2 +
>   hw/display/vga-mmio.c    | 132 +++++++++++++++++++++++++++------------
>   2 files changed, 94 insertions(+), 40 deletions(-)
>
> diff --git a/include/hw/display/vga.h b/include/hw/display/vga.h
> index c16a5c26dae..98b2e560f9b 100644
> --- a/include/hw/display/vga.h
> +++ b/include/hw/display/vga.h
> @@ -24,6 +24,8 @@ enum vga_retrace_method {
>   
>   extern enum vga_retrace_method vga_retrace_method;
>   
> +#define TYPE_VGA_MMIO "vga-mmio"
> +
>   int vga_mmio_init(hwaddr vram_base, hwaddr ctrl_base,
>                     int it_shift, MemoryRegion *address_space);
>   
> diff --git a/hw/display/vga-mmio.c b/hw/display/vga-mmio.c
> index 5671fdb920f..10bde32af5c 100644
> --- a/hw/display/vga-mmio.c
> +++ b/hw/display/vga-mmio.c
> @@ -23,21 +23,34 @@
>    */
>   
>   #include "qemu/osdep.h"
> -#include "qemu/bitops.h"
> -#include "qemu/units.h"
> -#include "migration/vmstate.h"
> +#include "qapi/error.h"
>   #include "hw/display/vga.h"
> +#include "hw/sysbus.h"
> +#include "hw/display/vga.h"
> +#include "hw/qdev-properties.h"
>   #include "vga_int.h"
> -#include "ui/pixel_ops.h"
>   
> -#define VGA_RAM_SIZE (8 * MiB)
> +/*
> + * QEMU interface:
> + *  + sysbus MMIO region 0: VGA I/O registers
> + *  + sysbus MMIO region 1: VGA MMIO registers
> + *  + sysbus MMIO region 2: VGA memory
> + */
>   
> -typedef struct VGAMmioState {
> +OBJECT_DECLARE_SIMPLE_TYPE(VGAMmioState, VGA_MMIO)
> +
> +struct VGAMmioState {
> +    /*< private >*/
> +    SysBusDevice parent_obj;
> +
> +    /*< public >*/
>       VGACommonState vga;
> -    int it_shift;
> -} VGAMmioState;
> +    MemoryRegion iomem;
> +    MemoryRegion lowmem;
> +
> +    uint8_t it_shift;
> +};
>   
> -/* Memory mapped interface */
>   static uint64_t vga_mm_read(void *opaque, hwaddr addr, unsigned size)
>   {
>       VGAMmioState *s = opaque;
> @@ -65,42 +78,81 @@ static const MemoryRegionOps vga_mm_ctrl_ops = {
>       .endianness = DEVICE_NATIVE_ENDIAN,
>   };
>   
> +static void vga_mmio_reset(DeviceState *dev)
> +{
> +    VGAMmioState *s = VGA_MMIO(dev);
> +
> +    vga_common_reset(&s->vga);
> +}
> +
>   int vga_mmio_init(hwaddr vram_base, hwaddr ctrl_base,
>                     int it_shift, MemoryRegion *address_space)
>   {
> -    VGAMmioState *s;
> -    MemoryRegion *s_ioport_ctrl, *vga_io_memory;
> +    DeviceState *dev;
> +    SysBusDevice *s;
>   
> -    s = g_malloc0(sizeof(*s));
> +    dev = qdev_new(TYPE_VGA_MMIO);
> +    qdev_prop_set_uint8(dev, "it_shift", it_shift);
> +    s = SYS_BUS_DEVICE(dev);
> +    sysbus_realize_and_unref(s, &error_fatal);
>   
> -    s->vga.vram_size_mb = VGA_RAM_SIZE / MiB;
> -    s->vga.global_vmstate = true;
> -    vga_common_init(&s->vga, NULL);
> -
> -    s->it_shift = it_shift;
> -    s_ioport_ctrl = g_malloc(sizeof(*s_ioport_ctrl));
> -    memory_region_init_io(s_ioport_ctrl, NULL, &vga_mm_ctrl_ops, s,
> -                          "vga-mm-ctrl", 0x100000);
> -    memory_region_set_flush_coalesced(s_ioport_ctrl);
> -
> -    vga_io_memory = g_malloc(sizeof(*vga_io_memory));
> -    /* XXX: endianness? */
> -    memory_region_init_io(vga_io_memory, NULL, &vga_mem_ops, &s->vga,
> -                          "vga-mem", 0x20000);
> -
> -    vmstate_register(NULL, 0, &vmstate_vga_common, s);
> -
> -    memory_region_add_subregion(address_space, ctrl_base, s_ioport_ctrl);
> -    s->vga.bank_offset = 0;
> -    memory_region_add_subregion(address_space,
> -                                vram_base + 0x000a0000, vga_io_memory);
> -    memory_region_set_coalescing(vga_io_memory);
> -
> -    s->vga.con = graphic_console_init(NULL, 0, s->vga.hw_ops, s);
> -
> -    memory_region_add_subregion(address_space,
> -                                VBE_DISPI_LFB_PHYSICAL_ADDRESS,
> -                                &s->vga.vram);
> +    sysbus_mmio_map(s, 0, ctrl_base);
> +    sysbus_mmio_map(s, 1, vram_base + 0x000a0000);
> +    sysbus_mmio_map(s, 2, VBE_DISPI_LFB_PHYSICAL_ADDRESS);
>   
>       return 0;
>   }
> +
> +static void vga_mmio_realizefn(DeviceState *dev, Error **errp)
> +{
> +    VGAMmioState *s = VGA_MMIO(dev);
> +    SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
> +
> +    memory_region_init_io(&s->iomem, OBJECT(dev), &vga_mm_ctrl_ops, s,
> +                          "vga-mmio", 0x100000);
> +    memory_region_set_flush_coalesced(&s->iomem);
> +    sysbus_init_mmio(sbd, &s->iomem);
> +
> +    /* XXX: endianness? */
> +    memory_region_init_io(&s->lowmem, OBJECT(dev), &vga_mem_ops, &s->vga,
> +                          "vga-lowmem", 0x20000);
> +    memory_region_set_coalescing(&s->lowmem);
> +    sysbus_init_mmio(sbd, &s->lowmem);
> +
> +    s->vga.bank_offset = 0;
> +    s->vga.global_vmstate = true;
> +    vga_common_init(&s->vga, OBJECT(dev));
> +    sysbus_init_mmio(sbd, &s->vga.vram);
> +    s->vga.con = graphic_console_init(dev, 0, s->vga.hw_ops, &s->vga);
> +}
> +
> +static Property vga_mmio_properties[] = {
> +    DEFINE_PROP_UINT8("it_shift", VGAMmioState, it_shift, 0),
> +    DEFINE_PROP_UINT32("vgamem_mb", VGAMmioState, vga.vram_size_mb, 8),
> +    DEFINE_PROP_END_OF_LIST(),
> +};
> +
> +static void vga_mmio_class_initfn(ObjectClass *klass, void *data)

Just a matter of taste, but I'd prefer "oc" instead of "klass".

Anyway:
Reviewed-by: Thomas Huth <thuth@redhat.com>