vfio-container-base: Introduce vfio_container_get_iova_ranges() helper

vfio-container-base: Introduce vfio_container_get_iova_ranges() helper

Introduce vfio_container_get_iova_ranges() to retrieve the usable
IOVA regions of the base container and use it in the Host IOMMU
device implementations of get_iova_ranges() callback.

We also fix a UAF bug as the list was shallow copied while
g_list_free_full() was used both on the single call site, in
virtio_iommu_set_iommu_device() but also in
vfio_container_instance_finalize(). Instead use g_list_copy_deep.

Fixes: cf2647a76e ("virtio-iommu: Compute host reserved regions")
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Suggested-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>