memory/iommu: QOM'fy IOMMU MemoryRegion

This defines new QOM object - IOMMUMemoryRegion - with MemoryRegion
as a parent.

This moves IOMMU-related fields from MR to IOMMU MR. However to avoid
dymanic QOM casting in fast path (address_space_translate, etc),
this adds an @is_iommu boolean flag to MR and provides new helper to
do simple cast to IOMMU MR - memory_region_get_iommu. The flag
is set in the instance init callback. This defines
memory_region_is_iommu as memory_region_get_iommu()!=NULL.

This switches MemoryRegion to IOMMUMemoryRegion in most places except
the ones where MemoryRegion may be an alias.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20170711035620.4232-2-aik@ozlabs.ru>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 6 insertions, 6 deletions

diff --git a/exec.c b/exec.c
index 2e8bc43421..2aa8be59ef 100644
--- a/exec.c
+++ b/exec.c
@@ -480,19 +480,19 @@ static MemoryRegionSection address_space_do_translate(AddressSpace *as,
 {
     IOMMUTLBEntry iotlb;
     MemoryRegionSection *section;
-    MemoryRegion *mr;
+    IOMMUMemoryRegion *iommu_mr;
 
     for (;;) {
         AddressSpaceDispatch *d = atomic_rcu_read(&as->dispatch);
         section = address_space_translate_internal(d, addr, &addr, plen, is_mmio);
-        mr = section->mr;
 
-        if (!mr->iommu_ops) {
+        iommu_mr = memory_region_get_iommu(section->mr);
+        if (!iommu_mr) {
             break;
         }
 
-        iotlb = mr->iommu_ops->translate(mr, addr, is_write ?
-                                         IOMMU_WO : IOMMU_RO);
+        iotlb = iommu_mr->iommu_ops->translate(iommu_mr, addr, is_write ?
+                                               IOMMU_WO : IOMMU_RO);
         addr = ((iotlb.translated_addr & ~iotlb.addr_mask)
                 | (addr & iotlb.addr_mask));
         *plen = MIN(*plen, (addr | iotlb.addr_mask) - addr + 1);
@@ -588,7 +588,7 @@ address_space_translate_for_iotlb(CPUState *cpu, int asidx, hwaddr addr,
 
     section = address_space_translate_internal(d, addr, xlat, plen, false);
 
-    assert(!section->mr->iommu_ops);
+    assert(!memory_region_is_iommu(section->mr));
     return section;
 }
 #endif