intel-iommu: Document iova_tree
commit8a7c606016d283a1716290c657f6f45bc7c4d817
authorPeter Xu <peterx@redhat.com>
Mon, 9 Jan 2023 19:37:27 +0000 (9 14:37 -0500)
committerMichael S. Tsirkin <mst@redhat.com>
Fri, 27 Jan 2023 16:47:02 +0000 (27 11:47 -0500)
tree824a507afcc15711d5dab06cb9b1bd65218e13f2
parentbad9c5a5166fd5e3a892b7b0477cf2f4bd3a959a
intel-iommu: Document iova_tree

It seems not super clear on when iova_tree is used, and why.  Add a rich
comment above iova_tree to track why we needed the iova_tree, and when we
need it.

Also comment for the map/unmap messages, on how they're used and
implications (e.g. unmap can be larger than the mapped ranges).

Suggested-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20230109193727.1360190-1-peterx@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
include/exec/memory.h
include/hw/i386/intel_iommu.h