On 23.03.22 12:17, Stefan Hajnoczi wrote: > When a RAMBlockNotifier is added, ->ram_block_added() is called with all > existing RAMBlocks. There is no equivalent ->ram_block_removed() call > when a RAMBlockNotifier is removed. > > The util/vfio-helpers.c code (the sole user of RAMBlockNotifier) is fine > with this asymmetry because it does not rely on RAMBlockNotifier for > cleanup. It walks its internal list of DMA mappings and unmaps them by > itself. > > Future users of RAMBlockNotifier may not have an internal data structure > that records added RAMBlocks so they will need ->ram_block_removed() > callbacks. > > This patch makes ram_block_notifier_remove() symmetric with respect to > callbacks. Now util/vfio-helpers.c needs to unmap remaining DMA mappings > after ram_block_notifier_remove() has been called. This is necessary > since users like block/nvme.c may create additional DMA mappings that do > not originate from the RAMBlockNotifier. > > Cc: David Hildenbrand <da...@redhat.com> > Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com>
Reviewed-by: David Hildenbrand <da...@redhat.com> -- Thanks, David / dhildenb
