PVSCSI_MAX_NUM_PAGES_REQ_RING
min(PVSCSI_MAX_NUM_PAGES_REQ_RING, pvscsi_ring_pages) *
adapter->req_pages = min(PVSCSI_MAX_NUM_PAGES_REQ_RING,
(PVSCSI_MAX_NUM_PAGES_REQ_RING * PVSCSI_MAX_NUM_REQ_ENTRIES_PER_PAGE)