iommu: Add IOMMU index argument to notifier APIs

Add support for multiple IOMMU indexes to the IOMMU notifier APIs.
When initializing a notifier with iommu_notifier_init(), the caller
must pass the IOMMU index that it is interested in. When a change
happens, the IOMMU implementation must pass
memory_region_notify_iommu() the IOMMU index that has changed and
that notifiers must be called for.

IOMMUs which support only a single index don't need to change.
Callers which only really support working with IOMMUs with a single
index can use the result of passing MEMTXATTRS_UNSPECIFIED to
memory_region_iommu_attrs_to_index().

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20180604152941.20374-3-peter.maydell@linaro.org

1 files changed, 6 insertions, 1 deletions

diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 96175b214d..b129cb9ddd 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -662,6 +662,8 @@ static void vhost_iommu_region_add(MemoryListener *listener,
                                          iommu_listener);
     struct vhost_iommu *iommu;
     Int128 end;
+    int iommu_idx;
+    IOMMUMemoryRegion *iommu_mr = IOMMU_MEMORY_REGION(section->mr);
 
     if (!memory_region_is_iommu(section->mr)) {
         return;
@@ -671,10 +673,13 @@ static void vhost_iommu_region_add(MemoryListener *listener,
     end = int128_add(int128_make64(section->offset_within_region),
                      section->size);
     end = int128_sub(end, int128_one());
+    iommu_idx = memory_region_iommu_attrs_to_index(iommu_mr,
+                                                   MEMTXATTRS_UNSPECIFIED);
     iommu_notifier_init(&iommu->n, vhost_iommu_unmap_notify,
                         IOMMU_NOTIFIER_UNMAP,
                         section->offset_within_region,
-                        int128_get64(end));
+                        int128_get64(end),
+                        iommu_idx);
     iommu->mr = section->mr;
     iommu->iommu_offset = section->offset_within_address_space -
                           section->offset_within_region;