Re: [PATCH-for-8.2 v4 09/10] hw/char/pl011: Add transmit FIFO to PL011State

[Richard Henderson]

On 11/9/23 11:28, Philippe Mathieu-Daudé wrote:
> @@ -436,6 +438,24 @@ static const VMStateDescription vmstate_pl011_clock = {
>       }
>   };
>   
> +static bool pl011_xmit_fifo_state_needed(void *opaque)
> +{
> +    PL011State* s = opaque;
> +
> +    return !fifo8_is_empty(&s->xmit_fifo);
> +}
> +
> +static const VMStateDescription vmstate_pl011_xmit_fifo = {
> +    .name = "pl011/xmit_fifo",
> +    .version_id = 1,
> +    .minimum_version_id = 1,
> +    .needed = pl011_xmit_fifo_state_needed,
> +    .fields = (VMStateField[]) {
> +        VMSTATE_FIFO8(xmit_fifo, PL011State),
> +        VMSTATE_END_OF_LIST()
> +    }
> +};
> +
>   static int pl011_post_load(void *opaque, int version_id)
>   {
>       PL011State* s = opaque;
> @@ -487,7 +507,11 @@ static const VMStateDescription vmstate_pl011 = {
>       .subsections = (const VMStateDescription * []) {
>           &vmstate_pl011_clock,
>           NULL
> -    }
> +    },
> +    .subsections = (const VMStateDescription * []) {
> +        &vmstate_pl011_xmit_fifo,
> +        NULL
> +    },
>   };

It just occurred to me that you may need a vmstate_pl011 pre_load() to empty the FIFO, 
which will then be filled if and only if the saved vmstate_pl011_xmit_fifo subsection is 
present.

Juan, have I got this correct about how migration would or should handle a 
missing subsection?


r~