Re: [PATCH] system: initialize target_page_bits as soon as possible

[Richard Henderson <richard.henderson@linaro.org>]

On 3/9/25 12:37, Pierrick Bouvier wrote:
> Allow device init functions to use it, which can be convenient in some
> cases (like hw/hyperv/hyperv.c).
> 
> Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
> ---
>   system/physmem.c | 1 -
>   system/vl.c      | 3 +++
>   2 files changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/system/physmem.c b/system/physmem.c
> index 8df9f30a0bb..c5fb784a9e1 100644
> --- a/system/physmem.c
> +++ b/system/physmem.c
> @@ -3281,7 +3281,6 @@ void cpu_exec_init_all(void)
>        * do this much later, rather than requiring board models to state
>        * up front what their requirements are.
>        */
> -    finalize_target_page_bits();
>       io_mem_init();
>       memory_map_init();
>   }
> diff --git a/system/vl.c b/system/vl.c
> index ec93988a03a..c64f8c8e808 100644
> --- a/system/vl.c
> +++ b/system/vl.c
> @@ -2848,6 +2848,9 @@ void qemu_init(int argc, char **argv)
>       bool userconfig = true;
>       FILE *vmstate_dump_file = NULL;
>   
> +    /* Set target page info before creating machine and associated devices */
> +    finalize_target_page_bits();

This is far too early, and therefore incorrect.

You have to wait until after all possible calls to set_preferred_target_page_bits(). The 
only relevant call is in arm_cpu_realizefn, invoked from the MachineClass.init, invoked 
from machine_run_board_init().


r~