Re: [PATCH v5 09/11] xen/arm: if direct-map domain use native addresses for GICv3

[Julien Grall <julien@xxxxxxx>]

Hi Penny,

On 27/01/2022 07:49, Penny Zheng wrote:
> diff --git a/xen/arch/arm/include/asm/domain.h 
> b/xen/arch/arm/include/asm/domain.h
> index cb37ce89ec..848fec8a0f 100644
> --- a/xen/arch/arm/include/asm/domain.h
> +++ b/xen/arch/arm/include/asm/domain.h
> @@ -31,6 +31,20 @@ enum domain_type {
>   
>   #define is_domain_direct_mapped(d) (d->arch.directmap)
>   
> +/*
> + * Is the domain using the host memory layout?
> + *
> + * Direct-mapped domain will always have the RAM mapped with GFN == MFN.
> + * To avoid any trouble finding space, it is easier to force using the
> + * host memory layout.
> + *
> + * The hardware domain will use the host layout regardless of
> + * direct-mapped because some OS may rely on a specific address ranges
> + * for the devices.
> + */
> +#define domain_use_host_layout(d) (is_domain_direct_mapped(d) || \
> +                                   is_hardware_domain(d))
> +
>   struct vtimer {
>       struct vcpu *v;
>       int irq;
> diff --git a/xen/arch/arm/vgic-v3.c b/xen/arch/arm/vgic-v3.c
> index 65bb7991a6..144089a7b6 100644
> --- a/xen/arch/arm/vgic-v3.c
> +++ b/xen/arch/arm/vgic-v3.c
> @@ -1640,14 +1640,15 @@ static inline unsigned int 
> vgic_v3_max_rdist_count(struct domain *d)
>        * Normally there is only one GICv3 redistributor region.
>        * The GICv3 DT binding provisions for multiple regions, since there are
>        * platforms out there which need those (multi-socket systems).
> -     * For Dom0 we have to live with the MMIO layout the hardware provides,
> -     * so we have to copy the multiple regions - as the first region may not
> -     * provide enough space to hold all redistributors we need.
> +     * For domain using the host memory layout, we have to live with the MMIO
> +     * layout the hardware provides, so we have to copy the multiple regions
> +     * - as the first region may not provide enough space to hold all
> +     * redistributors we need.
>        * However DomU get a constructed memory map, so we can go with
This sentence imply all domUs will use a constructed memory map. I would 
replace "However DomU" with "All the other domains will get a ...".
With that updated:

Reviewed-by: Julien Grall <jgrall@xxxxxxxxxx>

Cheers,

--
Julien Grall