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, 35 insertions, 20 deletions

diff --git a/include/exec/memory.h b/include/exec/memory.h
index 8503685455..92980abfad 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -35,6 +35,10 @@
 #define MEMORY_REGION(obj) \
         OBJECT_CHECK(MemoryRegion, (obj), TYPE_MEMORY_REGION)
 
+#define TYPE_IOMMU_MEMORY_REGION "qemu:iommu-memory-region"
+#define IOMMU_MEMORY_REGION(obj) \
+        OBJECT_CHECK(IOMMUMemoryRegion, (obj), TYPE_IOMMU_MEMORY_REGION)
+
 typedef struct MemoryRegionOps MemoryRegionOps;
 typedef struct MemoryRegionMmio MemoryRegionMmio;
 
@@ -198,16 +202,16 @@ struct MemoryRegionIOMMUOps {
      * set flag to IOMMU_NONE to mean that we don't need any
      * read/write permission checks, like, when for region replay.
      */
-    IOMMUTLBEntry (*translate)(MemoryRegion *iommu, hwaddr addr,
+    IOMMUTLBEntry (*translate)(IOMMUMemoryRegion *iommu, hwaddr addr,
                                IOMMUAccessFlags flag);
     /* Returns minimum supported page size */
-    uint64_t (*get_min_page_size)(MemoryRegion *iommu);
+    uint64_t (*get_min_page_size)(IOMMUMemoryRegion *iommu);
     /* Called when IOMMU Notifier flag changed */
-    void (*notify_flag_changed)(MemoryRegion *iommu,
+    void (*notify_flag_changed)(IOMMUMemoryRegion *iommu,
                                 IOMMUNotifierFlag old_flags,
                                 IOMMUNotifierFlag new_flags);
     /* Set this up to provide customized IOMMU replay function */
-    void (*replay)(MemoryRegion *iommu, IOMMUNotifier *notifier);
+    void (*replay)(IOMMUMemoryRegion *iommu, IOMMUNotifier *notifier);
 };
 
 typedef struct CoalescedMemoryRange CoalescedMemoryRange;
@@ -227,9 +231,9 @@ struct MemoryRegion {
     bool flush_coalesced_mmio;
     bool global_locking;
     uint8_t dirty_log_mask;
+    bool is_iommu;
     RAMBlock *ram_block;
     Object *owner;
-    const MemoryRegionIOMMUOps *iommu_ops;
 
     const MemoryRegionOps *ops;
     void *opaque;
@@ -252,6 +256,12 @@ struct MemoryRegion {
     const char *name;
     unsigned ioeventfd_nb;
     MemoryRegionIoeventfd *ioeventfds;
+};
+
+struct IOMMUMemoryRegion {
+    MemoryRegion parent_obj;
+
+    const MemoryRegionIOMMUOps *iommu_ops;
     QLIST_HEAD(, IOMMUNotifier) iommu_notify;
     IOMMUNotifierFlag iommu_notify_flags;
 };
@@ -618,13 +628,13 @@ static inline void memory_region_init_reservation(MemoryRegion *mr,
  * An IOMMU region translates addresses and forwards accesses to a target
  * memory region.
  *
- * @mr: the #MemoryRegion to be initialized
+ * @iommu_mr: the #IOMMUMemoryRegion to be initialized
  * @owner: the object that tracks the region's reference count
  * @ops: a function that translates addresses into the @target region
  * @name: used for debugging; not visible to the user or ABI
  * @size: size of the region.
  */
-void memory_region_init_iommu(MemoryRegion *mr,
+void memory_region_init_iommu(IOMMUMemoryRegion *iommu_mr,
                               struct Object *owner,
                               const MemoryRegionIOMMUOps *ops,
                               const char *name,
@@ -679,20 +689,25 @@ static inline bool memory_region_is_romd(MemoryRegion *mr)
 }
 
 /**
- * memory_region_is_iommu: check whether a memory region is an iommu
+ * memory_region_get_iommu: check whether a memory region is an iommu
  *
- * Returns %true is a memory region is an iommu.
+ * Returns pointer to IOMMUMemoryRegion if a memory region is an iommu,
+ * otherwise NULL.
  *
  * @mr: the memory region being queried
  */
-static inline bool memory_region_is_iommu(MemoryRegion *mr)
+static inline IOMMUMemoryRegion *memory_region_get_iommu(MemoryRegion *mr)
 {
     if (mr->alias) {
-        return memory_region_is_iommu(mr->alias);
+        return memory_region_get_iommu(mr->alias);
+    }
+    if (mr->is_iommu) {
+        return (IOMMUMemoryRegion *) mr;
     }
-    return mr->iommu_ops;
+    return NULL;
 }
 
+#define memory_region_is_iommu(mr) (memory_region_get_iommu(mr) != NULL)
 
 /**
  * memory_region_iommu_get_min_page_size: get minimum supported page size
@@ -700,9 +715,9 @@ static inline bool memory_region_is_iommu(MemoryRegion *mr)
  *
  * Returns minimum supported page size for an iommu.
  *
- * @mr: the memory region being queried
+ * @iommu_mr: the memory region being queried
  */
-uint64_t memory_region_iommu_get_min_page_size(MemoryRegion *mr);
+uint64_t memory_region_iommu_get_min_page_size(IOMMUMemoryRegion *iommu_mr);
 
 /**
  * memory_region_notify_iommu: notify a change in an IOMMU translation entry.
@@ -716,12 +731,12 @@ uint64_t memory_region_iommu_get_min_page_size(MemoryRegion *mr);
  * Note: for any IOMMU implementation, an in-place mapping change
  * should be notified with an UNMAP followed by a MAP.
  *
- * @mr: the memory region that was changed
+ * @iommu_mr: the memory region that was changed
  * @entry: the new entry in the IOMMU translation table.  The entry
  *         replaces all old entries for the same virtual I/O address range.
  *         Deleted entries have .@perm == 0.
  */
-void memory_region_notify_iommu(MemoryRegion *mr,
+void memory_region_notify_iommu(IOMMUMemoryRegion *iommu_mr,
                                 IOMMUTLBEntry entry);
 
 /**
@@ -756,18 +771,18 @@ void memory_region_register_iommu_notifier(MemoryRegion *mr,
  * a notifier with the minimum page granularity returned by
  * mr->iommu_ops->get_page_size().
  *
- * @mr: the memory region to observe
+ * @iommu_mr: the memory region to observe
  * @n: the notifier to which to replay iommu mappings
  */
-void memory_region_iommu_replay(MemoryRegion *mr, IOMMUNotifier *n);
+void memory_region_iommu_replay(IOMMUMemoryRegion *iommu_mr, IOMMUNotifier *n);
 
 /**
  * memory_region_iommu_replay_all: replay existing IOMMU translations
  * to all the notifiers registered.
  *
- * @mr: the memory region to observe
+ * @iommu_mr: the memory region to observe
  */
-void memory_region_iommu_replay_all(MemoryRegion *mr);
+void memory_region_iommu_replay_all(IOMMUMemoryRegion *iommu_mr);
 
 /**
  * memory_region_unregister_iommu_notifier: unregister a notifier for