Re: [PATCH v4 1/3] ramfb: add migration support

[Laszlo Ersek]

On 10/5/23 13:30, marcandre.lureau@redhat.com wrote:
> From: Marc-André Lureau <marcandre.lureau@redhat.com>
> 
> Implementing RAMFB migration is quite straightforward. One caveat is to
> treat the whole RAMFBCfg as a blob, since that's what is exposed to the
> guest directly. This avoid having to fiddle with endianness issues if we
> were to migrate fields individually as integers.
> 
> The devices using RAMFB will have to include ramfb_vmstate in their
> migration description.
> 
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> ---
>  include/hw/display/ramfb.h |  4 ++++
>  hw/display/ramfb.c         | 19 +++++++++++++++++++
>  2 files changed, 23 insertions(+)
> 
> diff --git a/include/hw/display/ramfb.h b/include/hw/display/ramfb.h
> index b33a2c467b..a7e0019144 100644
> --- a/include/hw/display/ramfb.h
> +++ b/include/hw/display/ramfb.h
> @@ -1,11 +1,15 @@
>  #ifndef RAMFB_H
>  #define RAMFB_H
>  
> +#include "migration/vmstate.h"
> +
>  /* ramfb.c */
>  typedef struct RAMFBState RAMFBState;
>  void ramfb_display_update(QemuConsole *con, RAMFBState *s);
>  RAMFBState *ramfb_setup(Error **errp);
>  
> +extern const VMStateDescription ramfb_vmstate;
> +
>  /* ramfb-standalone.c */
>  #define TYPE_RAMFB_DEVICE "ramfb"
>  
> diff --git a/hw/display/ramfb.c b/hw/display/ramfb.c
> index c2b002d534..477ef7272a 100644
> --- a/hw/display/ramfb.c
> +++ b/hw/display/ramfb.c
> @@ -28,6 +28,8 @@ struct QEMU_PACKED RAMFBCfg {
>      uint32_t stride;
>  };
>  
> +typedef struct RAMFBCfg RAMFBCfg;
> +
>  struct RAMFBState {
>      DisplaySurface *ds;
>      uint32_t width, height;
> @@ -116,6 +118,23 @@ void ramfb_display_update(QemuConsole *con, RAMFBState 
> *s)
>      dpy_gfx_update_full(con);
>  }
>  
> +static int ramfb_post_load(void *opaque, int version_id)
> +{
> +    ramfb_fw_cfg_write(opaque, 0, 0);
> +    return 0;
> +}
> +
> +const VMStateDescription ramfb_vmstate = {
> +    .name = "ramfb",
> +    .version_id = 1,
> +    .minimum_version_id = 1,
> +    .post_load = ramfb_post_load,
> +    .fields = (VMStateField[]) {
> +        VMSTATE_BUFFER_UNSAFE(cfg, RAMFBState, 0, sizeof(RAMFBCfg)),
> +        VMSTATE_END_OF_LIST()
> +    }
> +};
> +
>  RAMFBState *ramfb_setup(Error **errp)
>  {
>      FWCfgState *fw_cfg = fw_cfg_find();

Identical to v3, which I reviewed, so:

Reviewed-by: Laszlo Ersek <lersek@redhat.com>