Re: [RFC PATCH-for-10.1 3/4] tcg: Have tcg_req_mo() use runtime TCGContext::guest_mo

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

On 3/21/25 05:57, Philippe Mathieu-Daudé wrote:
> In order to use TCG with multiple targets, replace the
> compile time use of TCG_GUEST_DEFAULT_MO by a runtime
> access to tcg_ctx->guest_mo.
> 
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> ---
>   accel/tcg/internal-target.h | 4 +---
>   1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/accel/tcg/internal-target.h b/accel/tcg/internal-target.h
> index 1cb35dba99e..014ee756f9d 100644
> --- a/accel/tcg/internal-target.h
> +++ b/accel/tcg/internal-target.h
> @@ -49,11 +49,9 @@ G_NORETURN void cpu_io_recompile(CPUState *cpu, uintptr_t retaddr);
>    * Filter @type to the barrier that is required for the guest
>    * memory ordering vs the host memory ordering.  A non-zero
>    * result indicates that some barrier is required.
> - *
> - * This is a macro so that it's constant even without optimization.
>    */
>   #define tcg_req_mo(type) \
> -    ((type) & TCG_GUEST_DEFAULT_MO & ~TCG_TARGET_DEFAULT_MO)
> +    ((type) & tcg_ctx->guest_mo & ~TCG_TARGET_DEFAULT_MO)


Incorrect.  The setting in tcg_ctx is only valid during compilation.

This macro is used during execution, in cpu_req_mo(),
from the cpu memory access routines.


r~