qemu: Add patch to resolve MicroBlaze ethernet issues

* Add patch to resolve the QEMU segfault when a AXI Ethernet device
  attempts to transmit/recieve packets.
* Patch is from mailing list, back-ported for 1.6.1.

Signed-off-by: Nathan Rossi <nathan.rossi@xilinx.com>

2 files changed, 102 insertions, 0 deletions

diff --git a/recipes-devtools/qemu/files/qom_object_c_Split_out_object_and_class_caches.patch b/recipes-devtools/qemu/files/qom_object_c_Split_out_object_and_class_caches.patch
new file mode 100644
index 00000000..b64a8391
--- /dev/null
+++ b/recipes-devtools/qemu/files/qom_object_c_Split_out_object_and_class_caches.patch
@@ -0,0 +1,101 @@
+Subject: [qom,v1,1/1] qom/object.c: Split out object and class caches.
+From: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
+Message-Id: <23ad4a5a9283ffcf4fc384832f369df46db18ef6.1385612379.git.peter.crosthwaite@xilinx.com>
+To: qemu-devel@nongnu.org,
+        aliguori@us.ibm.com,
+        pbonzini@redhat.com
+Cc: afaerber@suse.de
+Date: Wed, 27 Nov 2013 20:27:33 -0800
+
+The object-cast and class-cast caches cannot be shared because class
+caching is conditional on the target type not being an interface and
+object caching is unconditional. Leads to a bug when a class cast
+to an interface follows an object cast to the same interface type:
+
+FooObject = FOO(obj);
+FooClass = FOO_GET_CLASS(obj);
+
+Where TYPE_FOO is an interface. The first (object) cast will be
+successful and cache the casting result (i.e. TYPE_FOO will be cached).
+The second (class) cast will then check the shared cast cache
+and register a hit. The issue is, when a class cast hits in the cache
+it just returns a pointer cast of the input class (i.e. the concrete
+class).
+
+When casting to an interface, the cast itself must return the
+interface class, not the concrete class. The implementation of class
+cast caching already ensures that the returned cast result is only
+a pointer cast before caching. The object cast logic however does
+not have this check.
+
+Resolve by just splitting the object and class caches.
+
+Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
+Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
+Upstream-Status: Pending [Pulled from upstream mailing list]
+---
+include/qom/object.h |  3 ++-
+ qom/object.c         | 13 +++++++------
+ 2 files changed, 9 insertions(+), 7 deletions(-)
+
+diff --git a/include/qom/object.h b/include/qom/object.h
+index a275db2..5f78847 100644
+--- a/include/qom/object.h
++++ b/include/qom/object.h
+@@ -358,7 +358,8 @@ struct ObjectClass
+     Type type;
+     GSList *interfaces;
+ 
+-    const char *cast_cache[OBJECT_CLASS_CAST_CACHE];
++    const char *object_cast_cache[OBJECT_CLASS_CAST_CACHE];
++    const char *class_cast_cache[OBJECT_CLASS_CAST_CACHE];
+ 
+     ObjectUnparent *unparent;
+ };
+diff --git a/qom/object.c b/qom/object.c
+index fc19cf6..21b5a0b 100644
+--- a/qom/object.c
++++ b/qom/object.c
+@@ -458,7 +458,7 @@ Object *object_dynamic_cast_assert(Object *obj, const char *typename,
+     Object *inst;
+ 
+     for (i = 0; obj && i < OBJECT_CLASS_CAST_CACHE; i++) {
+-        if (obj->class->cast_cache[i] == typename) {
++        if (obj->class->object_cast_cache[i] == typename) {
+             goto out;
+         }
+     }
+@@ -475,9 +475,10 @@ Object *object_dynamic_cast_assert(Object *obj, const char *typename,
+ 
+     if (obj && obj == inst) {
+         for (i = 1; i < OBJECT_CLASS_CAST_CACHE; i++) {
+-            obj->class->cast_cache[i - 1] = obj->class->cast_cache[i];
++            obj->class->object_cast_cache[i - 1] =
++                    obj->class->object_cast_cache[i];
+         }
+-        obj->class->cast_cache[i - 1] = typename;
++        obj->class->object_cast_cache[i - 1] = typename;
+     }
+ 
+ out:
+@@ -547,7 +548,7 @@ ObjectClass *object_class_dynamic_cast_assert(ObjectClass *class,
+     int i;
+ 
+     for (i = 0; class && i < OBJECT_CLASS_CAST_CACHE; i++) {
+-        if (class->cast_cache[i] == typename) {
++        if (class->class_cast_cache[i] == typename) {
+             ret = class;
+             goto out;
+         }
+@@ -568,9 +569,9 @@ ObjectClass *object_class_dynamic_cast_assert(ObjectClass *class,
+ #ifdef CONFIG_QOM_CAST_DEBUG
+     if (class && ret == class) {
+         for (i = 1; i < OBJECT_CLASS_CAST_CACHE; i++) {
+-            class->cast_cache[i - 1] = class->cast_cache[i];
++            class->class_cast_cache[i - 1] = class->class_cast_cache[i];
+         }
+-        class->cast_cache[i - 1] = typename;
++        class->class_cast_cache[i - 1] = typename;
+     }
+ out:
+ #endif
diff --git a/recipes-devtools/qemu/qemu_1.6.1.bbappend b/recipes-devtools/qemu/qemu_1.6.1.bbappend
index 584c2540..46211271 100644
--- a/recipes-devtools/qemu/qemu_1.6.1.bbappend
+++ b/recipes-devtools/qemu/qemu_1.6.1.bbappend
@@ -5,4 +5,5 @@ SRC_URI_append += " \
                 file://microblaze-Add-support-for-loading-initrd-images.patch \
                 file://HACK_target-arm_Harcode_the_SCU_offset.patch \
                 file://HACK_zynq_slcr_Bring_SLCR_out_of_reset_in_kernel_state.patch \
+                file://qom_object_c_Split_out_object_and_class_caches.patch \
                 "