Re: of AVR target page size

[Peter Maydell]

On Thu, 18 Mar 2021 at 10:18, Dr. David Alan Gilbert
<dgilbert@redhat.com> wrote:
> diff --git a/migration/ram.c b/migration/ram.c
> index 1ee7ff9c6d..f053d45f3c 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -81,6 +81,8 @@
>  /* 0x80 is reserved in migration.h start with 0x100 next */
>  #define RAM_SAVE_FLAG_COMPRESS_PAGE    0x100
>
> +#define RAM_SAVE_FLAG__MAX RAM_SAVE_FLAG_COMPRESS_PAGE
> +
>  static inline bool is_zero_range(uint8_t *p, uint64_t size)
>  {
>      return buffer_is_zero(p, size);
> @@ -4101,5 +4103,10 @@ static SaveVMHandlers savevm_ram_handlers = {
>  void ram_mig_init(void)
>  {
>      qemu_mutex_init(&XBZRLE.lock);
> +#ifndef TARGET_PAGE_BITS_VARY
> +    QEMU_BUILD_BUG_ON(RAM_SAVE_FLAG__MAX >= TARGET_PAGE_SIZE);
> +#else
> +    QEMU_BUILD_BUG_ON(RAM_SAVE_FLAG__MAX >= (1 << TARGET_PAGE_BITS_MIN));
> +#endif

You should just be able to check against TARGET_PAGE_BITS_MIN;
we set that for both the TARGET_PAGE_BITS_VARY and the don't-vary
case.

thanks
-- PMM