Re: [PATCH v2 3/3] xen/arm: Find automatically a PPI for the DOM0 event channel interrupt

[Ian Campbell <Ian.Campbell@citrix.com>]

On Thu, 2015-01-15 at 20:23 +0000, Julien Grall wrote:

Subject should be "Automatically find..."

> Use the new vgic interface to know which virtual PPI is free and use it
> for the event channel code.
> 
> At the DOM0 creation time, Xen still don't know which vIRQ will be free.

"...Xen still doesn't know..." or just "... Xen doesn't know..."

> diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
> index 3d4f317..d5959b5 100644
> --- a/xen/arch/arm/domain_build.c
> +++ b/xen/arch/arm/domain_build.c
> @@ -627,6 +627,16 @@ static int make_hypervisor_node(struct domain *d,

I'd prefer this not to be done in make_hypervisor_node, to keep
make_*_node purely about creating the DT, without other side effects, as
far as possible.

I think you can drop a placeholder here and update it around the time of
the calls to kernel_load and initrd_load from a new helper function
which allocates and updates. initrd_load does something similar.

>          return res;
>  
>      /*
> +     * The allocation of the event channel IRQ has been deferred until
> +     * now. At this time, all PPIs use by DOM0 has been registered

s/use/used/ and s/has/have/

> +     */
> +    res = vgic_allocate_virq(d, 0);
                                    ^ /* ppi */

if you don't want to split into a ppi and spi helper as mentioned on
previous patch.

Ian.