4f8a62a933
For UNMAP-only IOMMU notifiers, we don't need to walk the page tables. Fasten that procedure by skipping the page table walk. That should boost performance for UNMAP-only notifiers like vhost. CC: QEMU Stable <qemu-stable@nongnu.org> Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>