[Xen-devel] [PATCH v1] arm/irq: Reorder check when the IRQ is already used by someone

[Oleksandr Tyshchenko <olekstysh@xxxxxxxxx>]

Call irq_get_domain for the IRQ we are interested in
only after making sure that it is the guest IRQ to avoid
ASSERT(test_bit(_IRQ_GUEST, &desc->status)) triggering.

Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>
Signed-off-by: Andrii Anisov <andrii_anisov@xxxxxxxx>
---
 xen/arch/arm/irq.c | 32 +++++++++++++++++++-------------
 1 file changed, 19 insertions(+), 13 deletions(-)

diff --git a/xen/arch/arm/irq.c b/xen/arch/arm/irq.c
index 06d4843..508028b 100644
--- a/xen/arch/arm/irq.c
+++ b/xen/arch/arm/irq.c
@@ -477,26 +477,32 @@ int route_irq_to_guest(struct domain *d, unsigned int 
virq,
      */
     if ( desc->action != NULL )
     {
-        struct domain *ad = irq_get_domain(desc);
-
-        if ( test_bit(_IRQ_GUEST, &desc->status) && d == ad )
+        if ( test_bit(_IRQ_GUEST, &desc->status) )
         {
-            if ( irq_get_guest_info(desc)->virq != virq )
+            struct domain *ad = irq_get_domain(desc);
+
+            if ( d == ad )
+            {
+                if ( irq_get_guest_info(desc)->virq != virq )
+                {
+                    printk(XENLOG_G_ERR
+                           "d%u: IRQ %u is already assigned to vIRQ %u\n",
+                           d->domain_id, irq, irq_get_guest_info(desc)->virq);
+                    retval = -EBUSY;
+                }
+            }
+            else
             {
-                printk(XENLOG_G_ERR
-                       "d%u: IRQ %u is already assigned to vIRQ %u\n",
-                       d->domain_id, irq, irq_get_guest_info(desc)->virq);
+                printk(XENLOG_G_ERR "IRQ %u is already used by domain %u\n",
+                       irq, ad->domain_id);
                 retval = -EBUSY;
             }
-            goto out;
         }
-
-        if ( test_bit(_IRQ_GUEST, &desc->status) )
-            printk(XENLOG_G_ERR "IRQ %u is already used by domain %u\n",
-                   irq, ad->domain_id);
         else
+        {
             printk(XENLOG_G_ERR "IRQ %u is already used by Xen\n", irq);
-        retval = -EBUSY;
+            retval = -EBUSY;
+        }
         goto out;
     }
 
-- 
2.7.4


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