--- /dev/null
+/*-
+ * BSD LICENSE
+ *
+ * Copyright(c) 2010-2017 Intel Corporation. All rights reserved.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Intel Corporation nor the names of its
+ * contributors may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <linux/virtio_net.h>
+
+#include <rte_mbuf.h>
+#include <rte_memcpy.h>
+#include <rte_vhost.h>
+
+#include "main.h"
+
+/*
+ * A very simple vhost-user net driver implementation, without
+ * any extra features being enabled, such as TSO and mrg-Rx.
+ */
+
+void
+vs_vhost_net_setup(struct vhost_dev *dev)
+{
+ uint16_t i;
+ int vid = dev->vid;
+ struct vhost_queue *queue;
+
+ RTE_LOG(INFO, VHOST_CONFIG,
+ "setting builtin vhost-user net driver\n");
+
+ rte_vhost_get_negotiated_features(vid, &dev->features);
+ if (dev->features & (1 << VIRTIO_NET_F_MRG_RXBUF))
+ dev->hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
+ else
+ dev->hdr_len = sizeof(struct virtio_net_hdr);
+
+ rte_vhost_get_mem_table(vid, &dev->mem);
+
+ dev->nr_vrings = rte_vhost_get_vring_num(vid);
+ for (i = 0; i < dev->nr_vrings; i++) {
+ queue = &dev->queues[i];
+
+ queue->last_used_idx = 0;
+ queue->last_avail_idx = 0;
+ rte_vhost_get_vhost_vring(vid, i, &queue->vr);
+ }
+}
+
+void
+vs_vhost_net_remove(struct vhost_dev *dev)
+{
+ free(dev->mem);
+}
+
+static inline int __attribute__((always_inline))
+enqueue_pkt(struct vhost_dev *dev, struct rte_vhost_vring *vr,
+ struct rte_mbuf *m, uint16_t desc_idx)
+{
+ uint32_t desc_avail, desc_offset;
+ uint32_t mbuf_avail, mbuf_offset;
+ uint32_t cpy_len;
+ struct vring_desc *desc;
+ uint64_t desc_addr;
+ struct virtio_net_hdr virtio_hdr = {0, 0, 0, 0, 0, 0};
+ /* A counter to avoid desc dead loop chain */
+ uint16_t nr_desc = 1;
+
+ desc = &vr->desc[desc_idx];
+ desc_addr = rte_vhost_gpa_to_vva(dev->mem, desc->addr);
+ /*
+ * Checking of 'desc_addr' placed outside of 'unlikely' macro to avoid
+ * performance issue with some versions of gcc (4.8.4 and 5.3.0) which
+ * otherwise stores offset on the stack instead of in a register.
+ */
+ if (unlikely(desc->len < dev->hdr_len) || !desc_addr)
+ return -1;
+
+ rte_prefetch0((void *)(uintptr_t)desc_addr);
+
+ /* write virtio-net header */
+ *(struct virtio_net_hdr *)(uintptr_t)desc_addr = virtio_hdr;
+
+ desc_offset = dev->hdr_len;
+ desc_avail = desc->len - dev->hdr_len;
+
+ mbuf_avail = rte_pktmbuf_data_len(m);
+ mbuf_offset = 0;
+ while (mbuf_avail != 0 || m->next != NULL) {
+ /* done with current mbuf, fetch next */
+ if (mbuf_avail == 0) {
+ m = m->next;
+
+ mbuf_offset = 0;
+ mbuf_avail = rte_pktmbuf_data_len(m);
+ }
+
+ /* done with current desc buf, fetch next */
+ if (desc_avail == 0) {
+ if ((desc->flags & VRING_DESC_F_NEXT) == 0) {
+ /* Room in vring buffer is not enough */
+ return -1;
+ }
+ if (unlikely(desc->next >= vr->size ||
+ ++nr_desc > vr->size))
+ return -1;
+
+ desc = &vr->desc[desc->next];
+ desc_addr = rte_vhost_gpa_to_vva(dev->mem, desc->addr);
+ if (unlikely(!desc_addr))
+ return -1;
+
+ desc_offset = 0;
+ desc_avail = desc->len;
+ }
+
+ cpy_len = RTE_MIN(desc_avail, mbuf_avail);
+ rte_memcpy((void *)((uintptr_t)(desc_addr + desc_offset)),
+ rte_pktmbuf_mtod_offset(m, void *, mbuf_offset),
+ cpy_len);
+
+ mbuf_avail -= cpy_len;
+ mbuf_offset += cpy_len;
+ desc_avail -= cpy_len;
+ desc_offset += cpy_len;
+ }
+
+ return 0;
+}
+
+uint16_t
+vs_enqueue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mbuf **pkts, uint32_t count)
+{
+ struct vhost_queue *queue;
+ struct rte_vhost_vring *vr;
+ uint16_t avail_idx, free_entries, start_idx;
+ uint16_t desc_indexes[MAX_PKT_BURST];
+ uint16_t used_idx;
+ uint32_t i;
+
+ queue = &dev->queues[queue_id];
+ vr = &queue->vr;
+
+ avail_idx = *((volatile uint16_t *)&vr->avail->idx);
+ start_idx = queue->last_used_idx;
+ free_entries = avail_idx - start_idx;
+ count = RTE_MIN(count, free_entries);
+ count = RTE_MIN(count, (uint32_t)MAX_PKT_BURST);
+ if (count == 0)
+ return 0;
+
+ /* Retrieve all of the desc indexes first to avoid caching issues. */
+ rte_prefetch0(&vr->avail->ring[start_idx & (vr->size - 1)]);
+ for (i = 0; i < count; i++) {
+ used_idx = (start_idx + i) & (vr->size - 1);
+ desc_indexes[i] = vr->avail->ring[used_idx];
+ vr->used->ring[used_idx].id = desc_indexes[i];
+ vr->used->ring[used_idx].len = pkts[i]->pkt_len +
+ dev->hdr_len;
+ }
+
+ rte_prefetch0(&vr->desc[desc_indexes[0]]);
+ for (i = 0; i < count; i++) {
+ uint16_t desc_idx = desc_indexes[i];
+ int err;
+
+ err = enqueue_pkt(dev, vr, pkts[i], desc_idx);
+ if (unlikely(err)) {
+ used_idx = (start_idx + i) & (vr->size - 1);
+ vr->used->ring[used_idx].len = dev->hdr_len;
+ }
+
+ if (i + 1 < count)
+ rte_prefetch0(&vr->desc[desc_indexes[i+1]]);
+ }
+
+ rte_smp_wmb();
+
+ *(volatile uint16_t *)&vr->used->idx += count;
+ queue->last_used_idx += count;
+
+ /* flush used->idx update before we read avail->flags. */
+ rte_mb();
+
+ /* Kick the guest if necessary. */
+ if (!(vr->avail->flags & VRING_AVAIL_F_NO_INTERRUPT)
+ && (vr->callfd >= 0))
+ eventfd_write(vr->callfd, (eventfd_t)1);
+ return count;
+}
+
+static inline int __attribute__((always_inline))
+dequeue_pkt(struct vhost_dev *dev, struct rte_vhost_vring *vr,
+ struct rte_mbuf *m, uint16_t desc_idx,
+ struct rte_mempool *mbuf_pool)
+{
+ struct vring_desc *desc;
+ uint64_t desc_addr;
+ uint32_t desc_avail, desc_offset;
+ uint32_t mbuf_avail, mbuf_offset;
+ uint32_t cpy_len;
+ struct rte_mbuf *cur = m, *prev = m;
+ /* A counter to avoid desc dead loop chain */
+ uint32_t nr_desc = 1;
+
+ desc = &vr->desc[desc_idx];
+ if (unlikely((desc->len < dev->hdr_len)) ||
+ (desc->flags & VRING_DESC_F_INDIRECT))
+ return -1;
+
+ desc_addr = rte_vhost_gpa_to_vva(dev->mem, desc->addr);
+ if (unlikely(!desc_addr))
+ return -1;
+
+ /*
+ * We don't support ANY_LAYOUT, neither VERSION_1, meaning
+ * a Tx packet from guest must have 2 desc buffers at least:
+ * the first for storing the header and the others for
+ * storing the data.
+ *
+ * And since we don't support TSO, we could simply skip the
+ * header.
+ */
+ desc = &vr->desc[desc->next];
+ desc_addr = rte_vhost_gpa_to_vva(dev->mem, desc->addr);
+ if (unlikely(!desc_addr))
+ return -1;
+ rte_prefetch0((void *)(uintptr_t)desc_addr);
+
+ desc_offset = 0;
+ desc_avail = desc->len;
+ nr_desc += 1;
+
+ mbuf_offset = 0;
+ mbuf_avail = m->buf_len - RTE_PKTMBUF_HEADROOM;
+ while (1) {
+ cpy_len = RTE_MIN(desc_avail, mbuf_avail);
+ rte_memcpy(rte_pktmbuf_mtod_offset(cur, void *,
+ mbuf_offset),
+ (void *)((uintptr_t)(desc_addr + desc_offset)),
+ cpy_len);
+
+ mbuf_avail -= cpy_len;
+ mbuf_offset += cpy_len;
+ desc_avail -= cpy_len;
+ desc_offset += cpy_len;
+
+ /* This desc reaches to its end, get the next one */
+ if (desc_avail == 0) {
+ if ((desc->flags & VRING_DESC_F_NEXT) == 0)
+ break;
+
+ if (unlikely(desc->next >= vr->size ||
+ ++nr_desc > vr->size))
+ return -1;
+ desc = &vr->desc[desc->next];
+
+ desc_addr = rte_vhost_gpa_to_vva(dev->mem, desc->addr);
+ if (unlikely(!desc_addr))
+ return -1;
+ rte_prefetch0((void *)(uintptr_t)desc_addr);
+
+ desc_offset = 0;
+ desc_avail = desc->len;
+ }
+
+ /*
+ * This mbuf reaches to its end, get a new one
+ * to hold more data.
+ */
+ if (mbuf_avail == 0) {
+ cur = rte_pktmbuf_alloc(mbuf_pool);
+ if (unlikely(cur == NULL)) {
+ RTE_LOG(ERR, VHOST_DATA, "Failed to "
+ "allocate memory for mbuf.\n");
+ return -1;
+ }
+
+ prev->next = cur;
+ prev->data_len = mbuf_offset;
+ m->nb_segs += 1;
+ m->pkt_len += mbuf_offset;
+ prev = cur;
+
+ mbuf_offset = 0;
+ mbuf_avail = cur->buf_len - RTE_PKTMBUF_HEADROOM;
+ }
+ }
+
+ prev->data_len = mbuf_offset;
+ m->pkt_len += mbuf_offset;
+
+ return 0;
+}
+
+uint16_t
+vs_dequeue_pkts(struct vhost_dev *dev, uint16_t queue_id,
+ struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count)
+{
+ struct vhost_queue *queue;
+ struct rte_vhost_vring *vr;
+ uint32_t desc_indexes[MAX_PKT_BURST];
+ uint32_t used_idx;
+ uint32_t i = 0;
+ uint16_t free_entries;
+ uint16_t avail_idx;
+
+ queue = &dev->queues[queue_id];
+ vr = &queue->vr;
+
+ free_entries = *((volatile uint16_t *)&vr->avail->idx) -
+ queue->last_avail_idx;
+ if (free_entries == 0)
+ return 0;
+
+ /* Prefetch available and used ring */
+ avail_idx = queue->last_avail_idx & (vr->size - 1);
+ used_idx = queue->last_used_idx & (vr->size - 1);
+ rte_prefetch0(&vr->avail->ring[avail_idx]);
+ rte_prefetch0(&vr->used->ring[used_idx]);
+
+ count = RTE_MIN(count, MAX_PKT_BURST);
+ count = RTE_MIN(count, free_entries);
+
+ /*
+ * Retrieve all of the head indexes first and pre-update used entries
+ * to avoid caching issues.
+ */
+ for (i = 0; i < count; i++) {
+ avail_idx = (queue->last_avail_idx + i) & (vr->size - 1);
+ used_idx = (queue->last_used_idx + i) & (vr->size - 1);
+ desc_indexes[i] = vr->avail->ring[avail_idx];
+
+ vr->used->ring[used_idx].id = desc_indexes[i];
+ vr->used->ring[used_idx].len = 0;
+ }
+
+ /* Prefetch descriptor index. */
+ rte_prefetch0(&vr->desc[desc_indexes[0]]);
+ for (i = 0; i < count; i++) {
+ int err;
+
+ if (likely(i + 1 < count))
+ rte_prefetch0(&vr->desc[desc_indexes[i + 1]]);
+
+ pkts[i] = rte_pktmbuf_alloc(mbuf_pool);
+ if (unlikely(pkts[i] == NULL)) {
+ RTE_LOG(ERR, VHOST_DATA,
+ "Failed to allocate memory for mbuf.\n");
+ break;
+ }
+
+ err = dequeue_pkt(dev, vr, pkts[i], desc_indexes[i], mbuf_pool);
+ if (unlikely(err)) {
+ rte_pktmbuf_free(pkts[i]);
+ break;
+ }
+
+ }
+ if (!i)
+ return 0;
+
+ queue->last_avail_idx += i;
+ queue->last_used_idx += i;
+ rte_smp_wmb();
+ rte_smp_rmb();
+
+ vr->used->idx += i;
+
+ if (!(vr->avail->flags & VRING_AVAIL_F_NO_INTERRUPT)
+ && (vr->callfd >= 0))
+ eventfd_write(vr->callfd, (eventfd_t)1);
+
+ return i;
+}
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