Re: [PATCH v6 15/22] arm/acpi: Permit access all Xen unused SPIs for Dom0

[Julien Grall <julien.grall@arm.com>]

Hi Shannon,

On 17/03/16 09:41, Shannon Zhao wrote:
> From: Shannon Zhao <shannon.zhao@linaro.org>
>
> Permit access all Xen unused SPIs for Dom0 except the interrupts that
> Xen uses.

You say exactly the same things with all "Xen unused SPIs for Dom0" and 
"except the interrupts that Xen uses".

I would instead say:

"Allow DOM0 to use all SPIs but the ones used by Xen."

> Then when Dom0 configures the interrupt, it could set the
> interrupt type and route it to Dom0.
>
> Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
> Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> ---
>   xen/arch/arm/domain_build.c | 31 +++++++++++++++++++++++++++++++
>   1 file changed, 31 insertions(+)
>
> diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
> index 6726e45..1e5ee0e 100644
> --- a/xen/arch/arm/domain_build.c
> +++ b/xen/arch/arm/domain_build.c
> @@ -1359,6 +1359,33 @@ static int prepare_dtb(struct domain *d, struct kernel_info *kinfo)
>   #ifdef CONFIG_ACPI
>   #define ACPI_DOM0_FDT_MIN_SIZE 4096
>
> +static int acpi_permit_spi_access(struct domain *d)
> +{
> +    int i, res;
> +    struct irq_desc *desc;
> +
> +    /* Here just permit Dom0 to access the SPIs which Xen doesn't use. Then when

Coding style:

/*
  * FOo
  * Bar
  */

> +     * Dom0 configures the interrupt, set the interrupt type and route it to
> +     * Dom0.
> +     */
> +    for( i = NR_LOCAL_IRQS; i < vgic_num_irqs(d); i++ )
> +    {
> +        desc = irq_to_desc(i);
> +        if( desc->action != NULL)

Well some of the SPIs used by Xen may not be registered yet. For 
instance the SMMU driver doesn't register any SPIs until it's necessary 
(i.e a device is assigned to a domain).

> +            continue;
> +
> +        res = irq_permit_access(d, i);
> +        if ( res )
> +        {
> +            printk(XENLOG_ERR "Unable to permit to dom%u access to IRQ %u\n",
> +                   d->domain_id, i);
> +            return res;
> +        }
> +    }
> +
> +    return 0;
> +}
> +
>   static int make_chosen_node(const struct kernel_info *kinfo,
>                               struct membank tbl_add[])
>   {
> @@ -1849,6 +1876,10 @@ static int prepare_acpi(struct domain *d, struct kernel_info *kinfo)
>       if ( rc != 0 )
>           return rc;
>
> +    rc = acpi_permit_spi_access(d);
> +    if ( rc != 0 )
> +        return rc;
> +
>       return 0;
>   }
>   #else
>

-- 
Julien Grall

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel