Re: [PATCH v2 3/5] ramfb: implement migration support

[Marc-André Lureau]

Hi

On Mon, Oct 2, 2023 at 3:12 PM <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 following patches turns the migration only on machine >= 8.2.
>
> Fixes:
> https://bugzilla.redhat.com/show_bug.cgi?id=1859424
>
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> ---
>  hw/display/ramfb.c | 21 +++++++++++++++++++++
>  1 file changed, 21 insertions(+)
>
> diff --git a/hw/display/ramfb.c b/hw/display/ramfb.c
> index 79b9754a58..4aaaa7d653 100644
> --- a/hw/display/ramfb.c
> +++ b/hw/display/ramfb.c
> @@ -12,6 +12,7 @@
>   */
>
>  #include "qemu/osdep.h"
> +#include "migration/vmstate.h"
>  #include "qapi/error.h"
>  #include "hw/loader.h"
>  #include "hw/display/ramfb.h"
> @@ -28,6 +29,8 @@ struct QEMU_PACKED RAMFBCfg {
>      uint32_t stride;
>  };
>
> +typedef struct RAMFBCfg RAMFBCfg;
> +
>  struct RAMFBState {
>      DisplaySurface *ds;
>      uint32_t width, height;
> @@ -115,6 +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;
> +}
> +
> +static const VMStateDescription vmstate_ramfb = {
> +    .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();
> @@ -127,6 +147,7 @@ RAMFBState *ramfb_setup(Error **errp)
>
>      s = g_new0(RAMFBState, 1);
>
> +    vmstate_register(NULL, 0, &vmstate_ramfb, s);

wip:
I am going to make it attached to the actual device.




-- 
Marc-André Lureau