vhost: fix vring memory partially mapped

vhost: fix vring memory partially mapped

Only the mapping of the vring addresses is being ensured. This causes
errors when the vring size is larger than the IOTLB page size. E.g:
queue sizes > 256 for 4K IOTLB pages

Ensure the entire vring memory range gets mapped. Refactor duplicated
code for for IOTLB UPDATE and IOTLB INVALIDATE and add packed virtqueue
support.

Fixes: 09927b524969 ("vhost: translate ring addresses when IOMMU enabled")
Cc: stable@dpdk.org
Signed-off-by: Adrian Moreno <amorenoz@redhat.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>