xen/arm: domain_build: Black list devices using PPIs

Currently, the vGIC is not able to cope with hardware PPIs routed to guests.
One of the solutions to this problem is to skip any device that uses PPI
source completely while building the domain itself.

This patch goes through all the interrupt sources of a device and skip it
if one of the interrupts sources is a PPI. It fixes XEN boot on i.MX8MQ by
skipping the PMU node.

Suggested-by:  Julien Grall <julien.grall@arm.com>
Signed-off-by: Amit Singh Tomar <amittomer25@gmail.com>
Acked-by: Julien Grall <julien.grall@arm.com>

diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index d9836779d17c90e84b94ba32e4a20f028189fc5b..16ce5222ca21cdde285326b3dedf907cb3d6d504 100644 (file)
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -1353,7 +1353,7 @@ static int __init handle_node(struct domain *d, struct kernel_info *kinfo,
         { /* sentinel */ },
     };
     struct dt_device_node *child;
-    int res;
+    int res, i, nirq, irq_id;
     const char *name;
     const char *path;
 
@@ -1399,6 +1399,24 @@ static int __init handle_node(struct domain *d, struct kernel_info *kinfo,
         return 0;
     }
 
+    /*
+     * The vGIC does not support routing hardware PPIs to guest. So
+     * we need to skip any node using PPIs.
+     */
+    nirq = dt_number_of_irq(node);
+
+    for ( i = 0 ; i < nirq ; i++ )
+    {
+        irq_id = platform_get_irq(node, i);
+
+        /* PPIs ranges from ID 16 to 31 */
+        if ( irq_id >= 16 && irq_id < 32 )
+        {
+            dt_dprintk(" Skip it (using PPIs)\n");
+            return 0;
+        }
+    }
+
     /*
      * Xen is using some path for its own purpose. Warn if a node
      * already exists with the same path.