memory: add MemoryRegionIOMMUOps.replay() callback

Originally we have one memory_region_iommu_replay() function, which is
the default behavior to replay the translations of the whole IOMMU
region. However, on some platform like x86, we may want our own replay
logic for IOMMU regions. This patch adds one more hook for IOMMUOps for
the callback, and it'll override the default if set.
Reviewed-by: NDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: NEric Auger <eric.auger@redhat.com>
Reviewed-by: N\"Michael S. Tsirkin\" <mst@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <1491562755-23867-6-git-send-email-peterx@redhat.com>
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>

include/exec/memory.h

@@ -191,6 +191,8 @@ struct MemoryRegionIOMMUOps {
     void (*notify_flag_changed)(MemoryRegion *iommu,
                                 IOMMUNotifierFlag old_flags,
                                 IOMMUNotifierFlag new_flags);
+    /* Set this up to provide customized IOMMU replay function */
+    void (*replay)(MemoryRegion *iommu, IOMMUNotifier *notifier);
 };
 
 typedef struct CoalescedMemoryRange CoalescedMemoryRange;

memory.c

@@ -1626,6 +1626,12 @@ void memory_region_iommu_replay(MemoryRegion *mr, IOMMUNotifier *n,
     hwaddr addr, granularity;
     IOMMUTLBEntry iotlb;
 
+    /* If the IOMMU has its own replay callback, override */
+    if (mr->iommu_ops->replay) {
+        mr->iommu_ops->replay(mr, n);
+        return;
+    }
+
     granularity = memory_region_iommu_get_min_page_size(mr);
 
     for (addr = 0; addr < memory_region_size(mr); addr += granularity) {