+static void
+async_dma_map(struct virtio_net *dev, bool do_map)
+{
+ int ret = 0;
+ uint32_t i;
+ struct guest_page *page;
+
+ if (do_map) {
+ for (i = 0; i < dev->nr_guest_pages; i++) {
+ page = &dev->guest_pages[i];
+ ret = rte_vfio_container_dma_map(RTE_VFIO_DEFAULT_CONTAINER_FD,
+ page->host_user_addr,
+ page->host_iova,
+ page->size);
+ if (ret) {
+ /*
+ * DMA device may bind with kernel driver, in this case,
+ * we don't need to program IOMMU manually. However, if no
+ * device is bound with vfio/uio in DPDK, and vfio kernel
+ * module is loaded, the API will still be called and return
+ * with ENODEV.
+ *
+ * DPDK vfio only returns ENODEV in very similar situations
+ * (vfio either unsupported, or supported but no devices found).
+ * Either way, no mappings could be performed. We treat it as
+ * normal case in async path. This is a workaround.
+ */
+ if (rte_errno == ENODEV)
+ return;
+
+ /* DMA mapping errors won't stop VHOST_USER_SET_MEM_TABLE. */
+ VHOST_LOG_CONFIG(ERR, "DMA engine map failed\n");
+ }
+ }
+
+ } else {
+ for (i = 0; i < dev->nr_guest_pages; i++) {
+ page = &dev->guest_pages[i];
+ ret = rte_vfio_container_dma_unmap(RTE_VFIO_DEFAULT_CONTAINER_FD,
+ page->host_user_addr,
+ page->host_iova,
+ page->size);
+ if (ret) {
+ /* like DMA map, ignore the kernel driver case when unmap. */
+ if (rte_errno == EINVAL)
+ return;
+
+ VHOST_LOG_CONFIG(ERR, "DMA engine unmap failed\n");
+ }
+ }
+ }
+}
+