[Xen-changelog] [xen master] xen/arm: route_irq_to_guest: Check validity of the IRQ

[patchbot@xxxxxxx]

commit 86ce68f7bbf24269b9ebe4bd132a6f7d3455a6bf
Author:     Julien Grall <julien.grall@xxxxxxxxxx>
AuthorDate: Wed Apr 1 17:21:43 2015 +0100
Commit:     Ian Campbell <ian.campbell@xxxxxxxxxx>
CommitDate: Thu Apr 2 10:42:35 2015 +0100

    xen/arm: route_irq_to_guest: Check validity of the IRQ
    
    Currently Xen only supports SPIs routing for guest, add a function
    is_assignable_irq to check if we can assign a given IRQ to the guest.
    
    Secondly, make sure the vIRQ is not the greater than the number of IRQs
    configured in the vGIC and it's an SPI.
    
    Thirdly, when the IRQ is already assigned to the domain, check the user
    is not asking to use a different vIRQ than the one already bound.
    
    Finally, desc->arch.type which contains the IRQ type (i.e level/edge) must
    be correctly configured before. The misconfiguration can happen when:
        - the device has been blacklisted for the current platform
        - the IRQ has not been described in the device tree
    
    Also, use XENLOG_G_ERR in the error message within the function as it will
    be later called from a guest.
    
    Signed-off-by: Julien Grall <julien.grall@xxxxxxxxxx>
    Acked-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
    Acked-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
---
 xen/arch/arm/irq.c        |   59 +++++++++++++++++++++++++++++++++++++++++---
 xen/include/asm-arm/irq.h |    2 +
 2 files changed, 57 insertions(+), 4 deletions(-)

diff --git a/xen/arch/arm/irq.c b/xen/arch/arm/irq.c
index beb746a..4c3e381 100644
--- a/xen/arch/arm/irq.c
+++ b/xen/arch/arm/irq.c
@@ -387,6 +387,16 @@ err:
     return rc;
 }
 
+bool_t is_assignable_irq(unsigned int irq)
+{
+    /* For now, we can only route SPIs to the guest */
+    return ((irq >= NR_LOCAL_IRQS) && (irq < gic_number_lines()));
+}
+
+/*
+ * Route an IRQ to a specific guest.
+ * For now only SPIs are assignable to the guest.
+ */
 int route_irq_to_guest(struct domain *d, unsigned int virq,
                        unsigned int irq, const char * devname)
 {
@@ -396,6 +406,28 @@ int route_irq_to_guest(struct domain *d, unsigned int virq,
     unsigned long flags;
     int retval = 0;
 
+    if ( virq >= vgic_num_irqs(d) )
+    {
+        printk(XENLOG_G_ERR
+               "the vIRQ number %u is too high for domain %u (max = %u)\n",
+               irq, d->domain_id, vgic_num_irqs(d));
+        return -EINVAL;
+    }
+
+    /* Only routing to virtual SPIs is supported */
+    if ( virq < NR_LOCAL_IRQS )
+    {
+        printk(XENLOG_G_ERR "IRQ can only be routed to an SPI");
+        return -EINVAL;
+    }
+
+    if ( !is_assignable_irq(irq) )
+    {
+        printk(XENLOG_G_ERR "the IRQ%u is not routable\n", irq);
+        return -EINVAL;
+    }
+    desc = irq_to_desc(irq);
+
     action = xmalloc(struct irqaction);
     if ( !action )
         return -ENOMEM;
@@ -416,8 +448,18 @@ int route_irq_to_guest(struct domain *d, unsigned int virq,
 
     spin_lock_irqsave(&desc->lock, flags);
 
-    /* If the IRQ is already used by someone
-     *  - If it's the same domain -> Xen doesn't need to update the IRQ desc
+    if ( desc->arch.type == DT_IRQ_TYPE_INVALID )
+    {
+        printk(XENLOG_G_ERR "IRQ %u has not been configured\n", irq);
+        retval = -EIO;
+        goto out;
+    }
+
+    /*
+     * If the IRQ is already used by someone
+     *  - If it's the same domain -> Xen doesn't need to update the IRQ desc.
+     *  For safety check if we are not trying to assign the IRQ to a
+     *  different vIRQ.
      *  - Otherwise -> For now, don't allow the IRQ to be shared between
      *  Xen and domains.
      */
@@ -426,13 +468,22 @@ int route_irq_to_guest(struct domain *d, unsigned int 
virq,
         struct domain *ad = irq_get_domain(desc);
 
         if ( test_bit(_IRQ_GUEST, &desc->status) && 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;
+            }
             goto out;
+        }
 
         if ( test_bit(_IRQ_GUEST, &desc->status) )
-            printk(XENLOG_ERR "ERROR: IRQ %u is already used by domain %u\n",
+            printk(XENLOG_G_ERR "IRQ %u is already used by domain %u\n",
                    irq, ad->domain_id);
         else
-            printk(XENLOG_ERR "ERROR: IRQ %u is already used by Xen\n", irq);
+            printk(XENLOG_G_ERR "IRQ %u is already used by Xen\n", irq);
         retval = -EBUSY;
         goto out;
     }
diff --git a/xen/include/asm-arm/irq.h b/xen/include/asm-arm/irq.h
index f00eb11..71b39e7 100644
--- a/xen/include/asm-arm/irq.h
+++ b/xen/include/asm-arm/irq.h
@@ -37,6 +37,8 @@ void do_IRQ(struct cpu_user_regs *regs, unsigned int irq, int 
is_fiq);
 
 #define domain_pirq_to_irq(d, pirq) (pirq)
 
+bool_t is_assignable_irq(unsigned int irq);
+
 void init_IRQ(void);
 void init_secondary_IRQ(void);
 
--
generated by git-patchbot for /home/xen/git/xen.git#master

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