Re: [PATCH 6/6] xen/arm: disable a physical IRQ when the guest disables the corresponding IRQ

[Julien Grall <julien.grall@linaro.org>]

On 12/06/2013 05:26 PM, Stefano Stabellini wrote:
> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> ---
>   xen/arch/arm/vgic.c |   17 +++++++++++++++++
>   1 file changed, 17 insertions(+)
>
> diff --git a/xen/arch/arm/vgic.c b/xen/arch/arm/vgic.c
> index 5b533ea..9ac24b0 100644
> --- a/xen/arch/arm/vgic.c
> +++ b/xen/arch/arm/vgic.c
> @@ -360,6 +360,21 @@ read_as_zero:
>       return 1;
>   }
>
> +static void vgic_disable_irqs(struct vcpu *v, uint32_t r, int n)
> +{
> +    struct pending_irq *p;
> +    unsigned int irq;
> +    int i = 0;
> +
> +    while ( (i = find_next_bit((const long unsigned int *) &r, 32, i)) < 32 ) {
> +        irq = i + (32 * n);
> +        p = irq_to_pending(v, irq);
> +        if ( p->desc != NULL )
> +            p->desc->handler->disable(p->desc);

Because of disable function will both both the GIC and irq_desc, you 
will need to take:
	- the GIC lock
         - the IRQ desc lock

-- 
Julien Grall