[Qemu-devel] [PATCH 2/2] kvm-openpic: Filter region add callbacks based on memory region offset

[Bogdan Purcareata]

This is done due to the fact that the kvm-openpic region_add callbacks can be
invoked for sections generated from other memory regions as well. These
callbacks should handle only requests for the kvm-openpic memory region.

The patch fixes a bug on target-ppc occuring when the "e500-pci-bar0" memory
region is added. This memory region registers an alias to the "e500-ccsr" memory
region, which further contains the "kvm-openpic" subregion. Due to this alias,
the kvm_openpic_region_add is called once more, with an offset within the
"e500-pci-bar" memory region. This generates the remapping of the
in-kernel MPIC at a wrong offset.

The fix consists in an additional filter in kvm_openpic_region_add to consider
only addresses matching the start of the kvm-openpic memory region.

Signed-off-by: Bogdan Purcareata <address@hidden>
Signed-off-by: Mihai Caraman <address@hidden>
---
 hw/intc/openpic_kvm.c |    5 +++++
 1 file changed, 5 insertions(+)

diff --git a/hw/intc/openpic_kvm.c b/hw/intc/openpic_kvm.c
index e3bce04..b02de40 100644
--- a/hw/intc/openpic_kvm.c
+++ b/hw/intc/openpic_kvm.c
@@ -128,6 +128,11 @@ static void kvm_openpic_region_add(MemoryListener 
*listener,
         return;
     }
 
+    /* Ignore events on regions that are not at the MPIC offset */
+    if (section->offset_within_address_space !=
+            memory_region_address_space_offset(section->mr))
+        return;
+
     reg_base = section->offset_within_address_space;
 
     attr.group = KVM_DEV_MPIC_GRP_MISC;
-- 
1.7.10.4