[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] [PATCH v2 08/21] xen/arm: Initialize the virtual GIC later

On 29/08/14 15:49, Andrii Tseglytskyi wrote:
On Fri, Aug 29, 2014 at 9:57 PM, Julien Grall <julien.grall@xxxxxxxxxx> wrote:
You will have to modify the function for your purpose. If you plan to PIRQ
== VIRQ every time, you could do smth like:

d->arch.vgic.nr_spis = gic_number_lines() - 32;

I assume, you already modified vgic_allocate_irq to return directly the
pirq, and do nothing in vgic_free_irq.

Yes, locally I did the same as you mentioned, but I'm thinking about
solution which will allow me to have 1 to 1 irq mapping and which will
be acceptable for Xen mainline.

IHMO, the best solution would adding a boolean in the new DOMCTL to specify if we want to use PIRQ == VIRQ or not.

Then you will have to modify vgic_allocate_irq to return the physical IRQ if the domain as this new option enabled.

My local diff is:

diff --git a/xen/arch/arm/physdev.c b/xen/arch/arm/physdev.c
index 9333aa0..50ff100 100644
--- a/xen/arch/arm/physdev.c
+++ b/xen/arch/arm/physdev.c
@@ -46,16 +46,13 @@ static int physdev_map_pirq(domid_t domid, int
type, int index, int *pirq_p)

      virq = vgic_allocate_virq(d, irq);
      ret = -EMFILE;
      if ( virq == -1 )
          goto free_domain;

-    ret = route_irq_to_guest(d, virq, irq, "routed IRQ");
+    ret = route_irq_to_guest(d, irq, irq, "routed IRQ");

With this change you may have some issue when unmap_pirq is used. I would modify vgic_allocate_irq to always return the physical IRQ number.

The code will be also more clean.

Julien Grall

Xen-devel mailing list



Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.