intel-iommu: fail MAP notifier without caching mode

intel-iommu: fail MAP notifier without caching mode

Without caching mode, MAP notifier won't work correctly since guest
won't send IOTLB update event when it establishes new mappings in the
I/O page tables. Let's fail the IOMMU notifiers early instead of
misbehaving silently.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Viktor Prutyanov <viktor@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20230223065924.42503-2-jasowang@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
(cherry picked from commit b8d78277c091f26fdd64f239bc8bb7e55d74cecf)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>