[Qemu-devel] [PATCH 1/3] memory: add one flag for IOMMU notifier

[Peter Xu <peterx@redhat.com>]

With the new flag, now we allow to register two kinds of IOMMU
notifiers:

- IOMMU_RW:   All DMA mapping changes will be notified.
- IOMMU_NONE: will only be notified when there are cache invalidations.

Here IOMMU_RW is the original scemantics for existing IOMMU notifiers.
VFIO is the only register for IOMMU notifier, and it's with type
IOMMU_RW.

Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
---
 hw/i386/intel_iommu.c | 3 ++-
 hw/ppc/spapr_iommu.c  | 3 ++-
 hw/vfio/common.c      | 3 ++-
 include/exec/memory.h | 8 ++++++--
 memory.c              | 6 ++++--
 5 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index 28c31a2..e0d4f23 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -1974,7 +1974,8 @@ static IOMMUTLBEntry vtd_iommu_translate(MemoryRegion *iommu, hwaddr addr,
     return ret;
 }
 
-static void vtd_iommu_notify_started(MemoryRegion *iommu)
+static void vtd_iommu_notify_started(MemoryRegion *iommu,
+                                     IOMMUAccessFlags flag)
 {
     VTDAddressSpace *vtd_as = container_of(iommu, VTDAddressSpace, iommu);
 
diff --git a/hw/ppc/spapr_iommu.c b/hw/ppc/spapr_iommu.c
index 6bc4d4d..09660fc 100644
--- a/hw/ppc/spapr_iommu.c
+++ b/hw/ppc/spapr_iommu.c
@@ -156,7 +156,8 @@ static uint64_t spapr_tce_get_min_page_size(MemoryRegion *iommu)
     return 1ULL << tcet->page_shift;
 }
 
-static void spapr_tce_notify_started(MemoryRegion *iommu)
+static void spapr_tce_notify_started(MemoryRegion *iommu,
+                                     IOMMUAccessFlags flag)
 {
     spapr_tce_set_need_vfio(container_of(iommu, sPAPRTCETable, iommu), true);
 }
diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index b313e7c..b2d1fad 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -456,7 +456,8 @@ static void vfio_listener_region_add(MemoryListener *listener,
         giommu->n.notify = vfio_iommu_map_notify;
         QLIST_INSERT_HEAD(&container->giommu_list, giommu, giommu_next);
 
-        memory_region_register_iommu_notifier(giommu->iommu, &giommu->n);
+        memory_region_register_iommu_notifier(giommu->iommu, &giommu->n,
+                                              IOMMU_RW);
         memory_region_iommu_replay(giommu->iommu, &giommu->n, false);
 
         return;
diff --git a/include/exec/memory.h b/include/exec/memory.h
index 3e4d416..6c16a86 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -154,7 +154,7 @@ struct MemoryRegionIOMMUOps {
     /* Returns minimum supported page size */
     uint64_t (*get_min_page_size)(MemoryRegion *iommu);
     /* Called when the first notifier is set */
-    void (*notify_started)(MemoryRegion *iommu);
+    void (*notify_started)(MemoryRegion *iommu, IOMMUAccessFlags flag);
     /* Called when the last notifier is removed */
     void (*notify_stopped)(MemoryRegion *iommu);
 };
@@ -623,8 +623,12 @@ void memory_region_notify_iommu(MemoryRegion *mr,
  * @n: the notifier to be added; the notifier receives a pointer to an
  *     #IOMMUTLBEntry as the opaque value; the pointer ceases to be
  *     valid on exit from the notifier.
+ * @flag: kind of notifer to request. IOMMU_RW for notifying all
+ *        events (including additions), and IOMMU_NONE for notifying
+ *        cache invalidations only.
  */
-void memory_region_register_iommu_notifier(MemoryRegion *mr, Notifier *n);
+void memory_region_register_iommu_notifier(MemoryRegion *mr, Notifier *n,
+                                           IOMMUAccessFlags flag);
 
 /**
  * memory_region_iommu_replay: replay existing IOMMU translations to
diff --git a/memory.c b/memory.c
index 0eb6895..747a9ec 100644
--- a/memory.c
+++ b/memory.c
@@ -1513,11 +1513,13 @@ bool memory_region_is_logging(MemoryRegion *mr, uint8_t client)
     return memory_region_get_dirty_log_mask(mr) & (1 << client);
 }
 
-void memory_region_register_iommu_notifier(MemoryRegion *mr, Notifier *n)
+void memory_region_register_iommu_notifier(MemoryRegion *mr, Notifier *n,
+                                           IOMMUAccessFlags flag)
 {
+    assert(flag == IOMMU_NONE || flag == IOMMU_RW);
     if (mr->iommu_ops->notify_started &&
         QLIST_EMPTY(&mr->iommu_notify.notifiers)) {
-        mr->iommu_ops->notify_started(mr);
+        mr->iommu_ops->notify_started(mr, flag);
     }
     notifier_list_add(&mr->iommu_notify, n);
 }
-- 
2.7.4