Re: [PATCH v1 4/4] xen: arm: Enclose access to EL2 MMU specific registers under CONFIG_MMU

[Julien Grall <julien@xxxxxxx>]

Hi,

On 02/08/2024 13:14, Ayan Kumar Halder wrote:
> All the EL2 MMU specific registers are enclosed within CONFIG_MMU.
>
> Signed-off-by: Ayan Kumar Halder <ayan.kumar.halder@xxxxxxx>
> ---
>   xen/arch/arm/traps.c | 6 +++++-
>   1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/xen/arch/arm/traps.c b/xen/arch/arm/traps.c
> index aac6c599f8..766aacee77 100644
> --- a/xen/arch/arm/traps.c
> +++ b/xen/arch/arm/traps.c
> @@ -919,12 +919,14 @@ static void _show_registers(const struct cpu_user_regs 
> *regs,
>   #endif
>       }
>       printk("  VTCR_EL2: %"PRIregister"\n", READ_SYSREG(VTCR_EL2));
> -    printk(" VTTBR_EL2: %016"PRIx64"\n", ctxt->vttbr_el2);
Can you #ifdef the field vttrb_el2 if it is not meant to be used?

>       printk("\n");
>   
>       printk(" SCTLR_EL2: %"PRIregister"\n", READ_SYSREG(SCTLR_EL2));
>       printk("   HCR_EL2: %"PRIregister"\n", READ_SYSREG(HCR_EL2));
> +#ifdef CONFIG_MMU
> +    printk(" VTTBR_EL2: %016"PRIx64"\n", ctxt->vttbr_el2);
VTCR_EL2 and VTTBR_EL2 needs to be read together. So I would prefer the 
printk is not moved.
>       printk(" TTBR0_EL2: %016"PRIx64"\n", READ_SYSREG64(TTBR0_EL2));
> +#endif
>       printk("\n");>       printk("   ESR_EL2: %"PRIregister"\n", 
regs->hsr);
>       printk(" HPFAR_EL2: %"PRIregister"\n", READ_SYSREG(HPFAR_EL2));
> @@ -956,7 +958,9 @@ void show_registers(const struct cpu_user_regs *regs)
>       if ( guest_mode(regs) && is_32bit_domain(current->domain) )
>           ctxt.ifsr32_el2 = READ_SYSREG(IFSR32_EL2);
>   #endif
> +#ifdef CONFIG_MMU
>       ctxt.vttbr_el2 = READ_SYSREG64(VTTBR_EL2);
> +#endif
>   
>       _show_registers(regs, &ctxt, guest_mode(regs), current);
>   }
Cheers,

--
Julien Grall