Re: [PATCH v2 4/4] tests/tcg/aarch64: Extend MTE gdbstub tests to system mode

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

On 8/8/24 15:15, Gustavo Romero wrote:
> diff --git a/tests/tcg/aarch64/system/boot.S b/tests/tcg/aarch64/system/boot.S
> index 501685d0ec..79a2ada74a 100644
> --- a/tests/tcg/aarch64/system/boot.S
> +++ b/tests/tcg/aarch64/system/boot.S
> @@ -135,6 +135,17 @@ __start:
>   	orr	x1, x1, x3
>   	str	x1, [x2]			/* 2nd 2mb (.data & .bss)*/
>   
> +        /* Third block: .mte_page */
> +	adrp	x1, .mte_page
> +	add	x1, x1, :lo12:.mte_page
> +	bic	x1, x1, #(1 << 21) - 1

A bit silly to add in the low 12 bits and then mask them out again immediately.
I see that's common silliness with the other two ptes.

> diff --git a/tests/tcg/aarch64/system/kernel.ld b/tests/tcg/aarch64/system/kernel.ld
> index 7b3a76dcbf..7c00c1c378 100644
> --- a/tests/tcg/aarch64/system/kernel.ld
> +++ b/tests/tcg/aarch64/system/kernel.ld
> @@ -18,6 +18,11 @@ SECTIONS
>       .bss : {
>           *(.bss)
>       }
> +    /* align MTE section to next (third) 2mb */
> +    . = ALIGN(1 << 22);
> +    .mte : {
> +        *(.mte_page)
> +    }

This is likely to add 2mb of useless stuff to the image.

Maybe better to just define a symbol:

     mte_page = ALIGN(1 << 22);

and reference that instead.

Otherwise this looks good.


r~