[Qemu-devel] [PATCH 17/21] introduce memory_region_get_address() and use it in kvm/ioapic

[Igor Mammedov <imammedo@redhat.com>]

kvm/ioapic is relying on the fact that SysBus device
maps mmio regions with offset counted from start of system memory.
But if ioapic's region is moved to another sub-region which doesn't
start at the beginning of system memory then using offset isn't correct.

Fix kvm/ioapic by providing and using helper function that returns
absolute region address in respective address space.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
---
Note:
  next patch "move IOAPIC to ICC bus" converts IOAPICs to ICCDevice
  and breaks SysBus device assumption used by kvm/ioapic.
---
 hw/i386/kvm/ioapic.c  |    2 +-
 include/exec/memory.h |   10 ++++++++++
 memory.c              |   11 +++++++++++
 3 files changed, 22 insertions(+), 1 deletions(-)

diff --git a/hw/i386/kvm/ioapic.c b/hw/i386/kvm/ioapic.c
index a3bd519..b80d41a 100644
--- a/hw/i386/kvm/ioapic.c
+++ b/hw/i386/kvm/ioapic.c
@@ -96,7 +96,7 @@ static void kvm_ioapic_put(IOAPICCommonState *s)
 
     kioapic->id = s->id;
     kioapic->ioregsel = s->ioregsel;
-    kioapic->base_address = s->busdev.mmio[0].addr;
+    kioapic->base_address = memory_region_get_address(&s->io_memory);
     kioapic->irr = s->irr;
     for (i = 0; i < IOAPIC_NUM_PINS; i++) {
         kioapic->redirtbl[i].bits = s->ioredtbl[i];
diff --git a/include/exec/memory.h b/include/exec/memory.h
index 9e88320..954f353 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -706,6 +706,16 @@ void memory_region_set_enabled(MemoryRegion *mr, bool enabled);
 void memory_region_set_address(MemoryRegion *mr, hwaddr addr);
 
 /*
+ * memory_region_get_address: get current the address of a region
+ *
+ * Returns the absolute address of a region.
+ * May be used on regions that are currently part of a memory hierarchy.
+ *
+ * @mr: the region being queried
+ */
+hwaddr memory_region_get_address(MemoryRegion *mr);
+
+/*
  * memory_region_set_alias_offset: dynamically update a memory alias's offset
  *
  * Dynamically updates the offset into the target region that an alias points
diff --git a/memory.c b/memory.c
index 75ca281..0651050 100644
--- a/memory.c
+++ b/memory.c
@@ -1413,6 +1413,17 @@ void memory_region_set_address(MemoryRegion *mr, hwaddr addr)
     memory_region_transaction_commit();
 }
 
+hwaddr memory_region_get_address(MemoryRegion *mr)
+{
+    hwaddr addr = mr->addr;
+
+    while (mr->parent) {
+        mr = mr->parent;
+        addr += mr->addr;
+    }
+    return addr;
+}
+
 void memory_region_set_alias_offset(MemoryRegion *mr, hwaddr offset)
 {
     assert(mr->alias);
-- 
1.7.1