summaryrefslogtreecommitdiffstats
path: root/src/dpdk_lib18/librte_vhost/vhost_rxtx.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/dpdk_lib18/librte_vhost/vhost_rxtx.c')
-rwxr-xr-xsrc/dpdk_lib18/librte_vhost/vhost_rxtx.c730
1 files changed, 730 insertions, 0 deletions
diff --git a/src/dpdk_lib18/librte_vhost/vhost_rxtx.c b/src/dpdk_lib18/librte_vhost/vhost_rxtx.c
new file mode 100755
index 00000000..ccfd82f4
--- /dev/null
+++ b/src/dpdk_lib18/librte_vhost/vhost_rxtx.c
@@ -0,0 +1,730 @@
+/*-
+ * BSD LICENSE
+ *
+ * Copyright(c) 2010-2014 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 <linux/virtio_net.h>
+
+#include <rte_mbuf.h>
+#include <rte_memcpy.h>
+#include <rte_virtio_net.h>
+
+#include "vhost-net-cdev.h"
+
+#define MAX_PKT_BURST 32
+
+/**
+ * This function adds buffers to the virtio devices RX virtqueue. Buffers can
+ * be received from the physical port or from another virtio device. A packet
+ * count is returned to indicate the number of packets that are succesfully
+ * added to the RX queue. This function works when mergeable is disabled.
+ */
+static inline uint32_t __attribute__((always_inline))
+virtio_dev_rx(struct virtio_net *dev, uint16_t queue_id,
+ struct rte_mbuf **pkts, uint32_t count)
+{
+ struct vhost_virtqueue *vq;
+ struct vring_desc *desc;
+ struct rte_mbuf *buff;
+ /* The virtio_hdr is initialised to 0. */
+ struct virtio_net_hdr_mrg_rxbuf virtio_hdr = {{0, 0, 0, 0, 0, 0}, 0};
+ uint64_t buff_addr = 0;
+ uint64_t buff_hdr_addr = 0;
+ uint32_t head[MAX_PKT_BURST], packet_len = 0;
+ uint32_t head_idx, packet_success = 0;
+ uint16_t avail_idx, res_cur_idx;
+ uint16_t res_base_idx, res_end_idx;
+ uint16_t free_entries;
+ uint8_t success = 0;
+
+ LOG_DEBUG(VHOST_DATA, "(%"PRIu64") virtio_dev_rx()\n", dev->device_fh);
+ if (unlikely(queue_id != VIRTIO_RXQ)) {
+ LOG_DEBUG(VHOST_DATA, "mq isn't supported in this version.\n");
+ return 0;
+ }
+
+ vq = dev->virtqueue[VIRTIO_RXQ];
+ count = (count > MAX_PKT_BURST) ? MAX_PKT_BURST : count;
+
+ /*
+ * As many data cores may want access to available buffers,
+ * they need to be reserved.
+ */
+ do {
+ res_base_idx = vq->last_used_idx_res;
+ avail_idx = *((volatile uint16_t *)&vq->avail->idx);
+
+ free_entries = (avail_idx - res_base_idx);
+ /*check that we have enough buffers*/
+ if (unlikely(count > free_entries))
+ count = free_entries;
+
+ if (count == 0)
+ return 0;
+
+ res_end_idx = res_base_idx + count;
+ /* vq->last_used_idx_res is atomically updated. */
+ /* TODO: Allow to disable cmpset if no concurrency in application. */
+ success = rte_atomic16_cmpset(&vq->last_used_idx_res,
+ res_base_idx, res_end_idx);
+ } while (unlikely(success == 0));
+ res_cur_idx = res_base_idx;
+ LOG_DEBUG(VHOST_DATA, "(%"PRIu64") Current Index %d| End Index %d\n",
+ dev->device_fh, res_cur_idx, res_end_idx);
+
+ /* Prefetch available ring to retrieve indexes. */
+ rte_prefetch0(&vq->avail->ring[res_cur_idx & (vq->size - 1)]);
+
+ /* Retrieve all of the head indexes first to avoid caching issues. */
+ for (head_idx = 0; head_idx < count; head_idx++)
+ head[head_idx] = vq->avail->ring[(res_cur_idx + head_idx) &
+ (vq->size - 1)];
+
+ /*Prefetch descriptor index. */
+ rte_prefetch0(&vq->desc[head[packet_success]]);
+
+ while (res_cur_idx != res_end_idx) {
+ /* Get descriptor from available ring */
+ desc = &vq->desc[head[packet_success]];
+
+ buff = pkts[packet_success];
+
+ /* Convert from gpa to vva (guest physical addr -> vhost virtual addr) */
+ buff_addr = gpa_to_vva(dev, desc->addr);
+ /* Prefetch buffer address. */
+ rte_prefetch0((void *)(uintptr_t)buff_addr);
+
+ /* Copy virtio_hdr to packet and increment buffer address */
+ buff_hdr_addr = buff_addr;
+ packet_len = rte_pktmbuf_data_len(buff) + vq->vhost_hlen;
+
+ /*
+ * If the descriptors are chained the header and data are
+ * placed in separate buffers.
+ */
+ if (desc->flags & VRING_DESC_F_NEXT) {
+ desc->len = vq->vhost_hlen;
+ desc = &vq->desc[desc->next];
+ /* Buffer address translation. */
+ buff_addr = gpa_to_vva(dev, desc->addr);
+ desc->len = rte_pktmbuf_data_len(buff);
+ } else {
+ buff_addr += vq->vhost_hlen;
+ desc->len = packet_len;
+ }
+
+ /* Update used ring with desc information */
+ vq->used->ring[res_cur_idx & (vq->size - 1)].id =
+ head[packet_success];
+ vq->used->ring[res_cur_idx & (vq->size - 1)].len = packet_len;
+
+ /* Copy mbuf data to buffer */
+ /* FIXME for sg mbuf and the case that desc couldn't hold the mbuf data */
+ rte_memcpy((void *)(uintptr_t)buff_addr,
+ rte_pktmbuf_mtod(buff, const void *),
+ rte_pktmbuf_data_len(buff));
+ PRINT_PACKET(dev, (uintptr_t)buff_addr,
+ rte_pktmbuf_data_len(buff), 0);
+
+ res_cur_idx++;
+ packet_success++;
+
+ rte_memcpy((void *)(uintptr_t)buff_hdr_addr,
+ (const void *)&virtio_hdr, vq->vhost_hlen);
+
+ PRINT_PACKET(dev, (uintptr_t)buff_hdr_addr, vq->vhost_hlen, 1);
+
+ if (res_cur_idx < res_end_idx) {
+ /* Prefetch descriptor index. */
+ rte_prefetch0(&vq->desc[head[packet_success]]);
+ }
+ }
+
+ rte_compiler_barrier();
+
+ /* Wait until it's our turn to add our buffer to the used ring. */
+ while (unlikely(vq->last_used_idx != res_base_idx))
+ rte_pause();
+
+ *(volatile uint16_t *)&vq->used->idx += count;
+ vq->last_used_idx = res_end_idx;
+
+ /* Kick the guest if necessary. */
+ if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT))
+ eventfd_write((int)vq->kickfd, 1);
+ return count;
+}
+
+static inline uint32_t __attribute__((always_inline))
+copy_from_mbuf_to_vring(struct virtio_net *dev, uint16_t res_base_idx,
+ uint16_t res_end_idx, struct rte_mbuf *pkt)
+{
+ uint32_t vec_idx = 0;
+ uint32_t entry_success = 0;
+ struct vhost_virtqueue *vq;
+ /* The virtio_hdr is initialised to 0. */
+ struct virtio_net_hdr_mrg_rxbuf virtio_hdr = {
+ {0, 0, 0, 0, 0, 0}, 0};
+ uint16_t cur_idx = res_base_idx;
+ uint64_t vb_addr = 0;
+ uint64_t vb_hdr_addr = 0;
+ uint32_t seg_offset = 0;
+ uint32_t vb_offset = 0;
+ uint32_t seg_avail;
+ uint32_t vb_avail;
+ uint32_t cpy_len, entry_len;
+
+ if (pkt == NULL)
+ return 0;
+
+ LOG_DEBUG(VHOST_DATA, "(%"PRIu64") Current Index %d| "
+ "End Index %d\n",
+ dev->device_fh, cur_idx, res_end_idx);
+
+ /*
+ * Convert from gpa to vva
+ * (guest physical addr -> vhost virtual addr)
+ */
+ vq = dev->virtqueue[VIRTIO_RXQ];
+ vb_addr =
+ gpa_to_vva(dev, vq->buf_vec[vec_idx].buf_addr);
+ vb_hdr_addr = vb_addr;
+
+ /* Prefetch buffer address. */
+ rte_prefetch0((void *)(uintptr_t)vb_addr);
+
+ virtio_hdr.num_buffers = res_end_idx - res_base_idx;
+
+ LOG_DEBUG(VHOST_DATA, "(%"PRIu64") RX: Num merge buffers %d\n",
+ dev->device_fh, virtio_hdr.num_buffers);
+
+ rte_memcpy((void *)(uintptr_t)vb_hdr_addr,
+ (const void *)&virtio_hdr, vq->vhost_hlen);
+
+ PRINT_PACKET(dev, (uintptr_t)vb_hdr_addr, vq->vhost_hlen, 1);
+
+ seg_avail = rte_pktmbuf_data_len(pkt);
+ vb_offset = vq->vhost_hlen;
+ vb_avail =
+ vq->buf_vec[vec_idx].buf_len - vq->vhost_hlen;
+
+ entry_len = vq->vhost_hlen;
+
+ if (vb_avail == 0) {
+ uint32_t desc_idx =
+ vq->buf_vec[vec_idx].desc_idx;
+ vq->desc[desc_idx].len = vq->vhost_hlen;
+
+ if ((vq->desc[desc_idx].flags
+ & VRING_DESC_F_NEXT) == 0) {
+ /* Update used ring with desc information */
+ vq->used->ring[cur_idx & (vq->size - 1)].id
+ = vq->buf_vec[vec_idx].desc_idx;
+ vq->used->ring[cur_idx & (vq->size - 1)].len
+ = entry_len;
+
+ entry_len = 0;
+ cur_idx++;
+ entry_success++;
+ }
+
+ vec_idx++;
+ vb_addr =
+ gpa_to_vva(dev, vq->buf_vec[vec_idx].buf_addr);
+
+ /* Prefetch buffer address. */
+ rte_prefetch0((void *)(uintptr_t)vb_addr);
+ vb_offset = 0;
+ vb_avail = vq->buf_vec[vec_idx].buf_len;
+ }
+
+ cpy_len = RTE_MIN(vb_avail, seg_avail);
+
+ while (cpy_len > 0) {
+ /* Copy mbuf data to vring buffer */
+ rte_memcpy((void *)(uintptr_t)(vb_addr + vb_offset),
+ (const void *)(rte_pktmbuf_mtod(pkt, char*) + seg_offset),
+ cpy_len);
+
+ PRINT_PACKET(dev,
+ (uintptr_t)(vb_addr + vb_offset),
+ cpy_len, 0);
+
+ seg_offset += cpy_len;
+ vb_offset += cpy_len;
+ seg_avail -= cpy_len;
+ vb_avail -= cpy_len;
+ entry_len += cpy_len;
+
+ if (seg_avail != 0) {
+ /*
+ * The virtio buffer in this vring
+ * entry reach to its end.
+ * But the segment doesn't complete.
+ */
+ if ((vq->desc[vq->buf_vec[vec_idx].desc_idx].flags &
+ VRING_DESC_F_NEXT) == 0) {
+ /* Update used ring with desc information */
+ vq->used->ring[cur_idx & (vq->size - 1)].id
+ = vq->buf_vec[vec_idx].desc_idx;
+ vq->used->ring[cur_idx & (vq->size - 1)].len
+ = entry_len;
+ entry_len = 0;
+ cur_idx++;
+ entry_success++;
+ }
+
+ vec_idx++;
+ vb_addr = gpa_to_vva(dev,
+ vq->buf_vec[vec_idx].buf_addr);
+ vb_offset = 0;
+ vb_avail = vq->buf_vec[vec_idx].buf_len;
+ cpy_len = RTE_MIN(vb_avail, seg_avail);
+ } else {
+ /*
+ * This current segment complete, need continue to
+ * check if the whole packet complete or not.
+ */
+ pkt = pkt->next;
+ if (pkt != NULL) {
+ /*
+ * There are more segments.
+ */
+ if (vb_avail == 0) {
+ /*
+ * This current buffer from vring is
+ * used up, need fetch next buffer
+ * from buf_vec.
+ */
+ uint32_t desc_idx =
+ vq->buf_vec[vec_idx].desc_idx;
+ vq->desc[desc_idx].len = vb_offset;
+
+ if ((vq->desc[desc_idx].flags &
+ VRING_DESC_F_NEXT) == 0) {
+ uint16_t wrapped_idx =
+ cur_idx & (vq->size - 1);
+ /*
+ * Update used ring with the
+ * descriptor information
+ */
+ vq->used->ring[wrapped_idx].id
+ = desc_idx;
+ vq->used->ring[wrapped_idx].len
+ = entry_len;
+ entry_success++;
+ entry_len = 0;
+ cur_idx++;
+ }
+
+ /* Get next buffer from buf_vec. */
+ vec_idx++;
+ vb_addr = gpa_to_vva(dev,
+ vq->buf_vec[vec_idx].buf_addr);
+ vb_avail =
+ vq->buf_vec[vec_idx].buf_len;
+ vb_offset = 0;
+ }
+
+ seg_offset = 0;
+ seg_avail = rte_pktmbuf_data_len(pkt);
+ cpy_len = RTE_MIN(vb_avail, seg_avail);
+ } else {
+ /*
+ * This whole packet completes.
+ */
+ uint32_t desc_idx =
+ vq->buf_vec[vec_idx].desc_idx;
+ vq->desc[desc_idx].len = vb_offset;
+
+ while (vq->desc[desc_idx].flags &
+ VRING_DESC_F_NEXT) {
+ desc_idx = vq->desc[desc_idx].next;
+ vq->desc[desc_idx].len = 0;
+ }
+
+ /* Update used ring with desc information */
+ vq->used->ring[cur_idx & (vq->size - 1)].id
+ = vq->buf_vec[vec_idx].desc_idx;
+ vq->used->ring[cur_idx & (vq->size - 1)].len
+ = entry_len;
+ entry_len = 0;
+ cur_idx++;
+ entry_success++;
+ seg_avail = 0;
+ cpy_len = RTE_MIN(vb_avail, seg_avail);
+ }
+ }
+ }
+
+ return entry_success;
+}
+
+/*
+ * This function works for mergeable RX.
+ */
+static inline uint32_t __attribute__((always_inline))
+virtio_dev_merge_rx(struct virtio_net *dev, uint16_t queue_id,
+ struct rte_mbuf **pkts, uint32_t count)
+{
+ struct vhost_virtqueue *vq;
+ uint32_t pkt_idx = 0, entry_success = 0;
+ uint16_t avail_idx, res_cur_idx;
+ uint16_t res_base_idx, res_end_idx;
+ uint8_t success = 0;
+
+ LOG_DEBUG(VHOST_DATA, "(%"PRIu64") virtio_dev_merge_rx()\n",
+ dev->device_fh);
+ if (unlikely(queue_id != VIRTIO_RXQ)) {
+ LOG_DEBUG(VHOST_DATA, "mq isn't supported in this version.\n");
+ }
+
+ vq = dev->virtqueue[VIRTIO_RXQ];
+ count = RTE_MIN((uint32_t)MAX_PKT_BURST, count);
+
+ if (count == 0)
+ return 0;
+
+ for (pkt_idx = 0; pkt_idx < count; pkt_idx++) {
+ uint32_t secure_len = 0;
+ uint16_t need_cnt;
+ uint32_t vec_idx = 0;
+ uint32_t pkt_len = pkts[pkt_idx]->pkt_len + vq->vhost_hlen;
+ uint16_t i, id;
+
+ do {
+ /*
+ * As many data cores may want access to available
+ * buffers, they need to be reserved.
+ */
+ res_base_idx = vq->last_used_idx_res;
+ res_cur_idx = res_base_idx;
+
+ do {
+ avail_idx = *((volatile uint16_t *)&vq->avail->idx);
+ if (unlikely(res_cur_idx == avail_idx)) {
+ LOG_DEBUG(VHOST_DATA,
+ "(%"PRIu64") Failed "
+ "to get enough desc from "
+ "vring\n",
+ dev->device_fh);
+ return pkt_idx;
+ } else {
+ uint16_t wrapped_idx =
+ (res_cur_idx) & (vq->size - 1);
+ uint32_t idx =
+ vq->avail->ring[wrapped_idx];
+ uint8_t next_desc;
+
+ do {
+ next_desc = 0;
+ secure_len += vq->desc[idx].len;
+ if (vq->desc[idx].flags &
+ VRING_DESC_F_NEXT) {
+ idx = vq->desc[idx].next;
+ next_desc = 1;
+ }
+ } while (next_desc);
+
+ res_cur_idx++;
+ }
+ } while (pkt_len > secure_len);
+
+ /* vq->last_used_idx_res is atomically updated. */
+ success = rte_atomic16_cmpset(&vq->last_used_idx_res,
+ res_base_idx,
+ res_cur_idx);
+ } while (success == 0);
+
+ id = res_base_idx;
+ need_cnt = res_cur_idx - res_base_idx;
+
+ for (i = 0; i < need_cnt; i++, id++) {
+ uint16_t wrapped_idx = id & (vq->size - 1);
+ uint32_t idx = vq->avail->ring[wrapped_idx];
+ uint8_t next_desc;
+ do {
+ next_desc = 0;
+ vq->buf_vec[vec_idx].buf_addr =
+ vq->desc[idx].addr;
+ vq->buf_vec[vec_idx].buf_len =
+ vq->desc[idx].len;
+ vq->buf_vec[vec_idx].desc_idx = idx;
+ vec_idx++;
+
+ if (vq->desc[idx].flags & VRING_DESC_F_NEXT) {
+ idx = vq->desc[idx].next;
+ next_desc = 1;
+ }
+ } while (next_desc);
+ }
+
+ res_end_idx = res_cur_idx;
+
+ entry_success = copy_from_mbuf_to_vring(dev, res_base_idx,
+ res_end_idx, pkts[pkt_idx]);
+
+ rte_compiler_barrier();
+
+ /*
+ * Wait until it's our turn to add our buffer
+ * to the used ring.
+ */
+ while (unlikely(vq->last_used_idx != res_base_idx))
+ rte_pause();
+
+ *(volatile uint16_t *)&vq->used->idx += entry_success;
+ vq->last_used_idx = res_end_idx;
+
+ /* Kick the guest if necessary. */
+ if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT))
+ eventfd_write((int)vq->kickfd, 1);
+ }
+
+ return count;
+}
+
+uint16_t
+rte_vhost_enqueue_burst(struct virtio_net *dev, uint16_t queue_id,
+ struct rte_mbuf **pkts, uint16_t count)
+{
+ if (unlikely(dev->features & (1 << VIRTIO_NET_F_MRG_RXBUF)))
+ return virtio_dev_merge_rx(dev, queue_id, pkts, count);
+ else
+ return virtio_dev_rx(dev, queue_id, pkts, count);
+}
+
+uint16_t
+rte_vhost_dequeue_burst(struct virtio_net *dev, uint16_t queue_id,
+ struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count)
+{
+ struct rte_mbuf *m, *prev;
+ struct vhost_virtqueue *vq;
+ struct vring_desc *desc;
+ uint64_t vb_addr = 0;
+ uint32_t head[MAX_PKT_BURST];
+ uint32_t used_idx;
+ uint32_t i;
+ uint16_t free_entries, entry_success = 0;
+ uint16_t avail_idx;
+
+ if (unlikely(queue_id != VIRTIO_TXQ)) {
+ LOG_DEBUG(VHOST_DATA, "mq isn't supported in this version.\n");
+ return 0;
+ }
+
+ vq = dev->virtqueue[VIRTIO_TXQ];
+ avail_idx = *((volatile uint16_t *)&vq->avail->idx);
+
+ /* If there are no available buffers then return. */
+ if (vq->last_used_idx == avail_idx)
+ return 0;
+
+ LOG_DEBUG(VHOST_DATA, "%s (%"PRIu64")\n", __func__,
+ dev->device_fh);
+
+ /* Prefetch available ring to retrieve head indexes. */
+ rte_prefetch0(&vq->avail->ring[vq->last_used_idx & (vq->size - 1)]);
+
+ /*get the number of free entries in the ring*/
+ free_entries = (avail_idx - vq->last_used_idx);
+
+ free_entries = RTE_MIN(free_entries, count);
+ /* Limit to MAX_PKT_BURST. */
+ free_entries = RTE_MIN(free_entries, MAX_PKT_BURST);
+
+ LOG_DEBUG(VHOST_DATA, "(%"PRIu64") Buffers available %d\n",
+ dev->device_fh, free_entries);
+ /* Retrieve all of the head indexes first to avoid caching issues. */
+ for (i = 0; i < free_entries; i++)
+ head[i] = vq->avail->ring[(vq->last_used_idx + i) & (vq->size - 1)];
+
+ /* Prefetch descriptor index. */
+ rte_prefetch0(&vq->desc[head[entry_success]]);
+ rte_prefetch0(&vq->used->ring[vq->last_used_idx & (vq->size - 1)]);
+
+ while (entry_success < free_entries) {
+ uint32_t vb_avail, vb_offset;
+ uint32_t seg_avail, seg_offset;
+ uint32_t cpy_len;
+ uint32_t seg_num = 0;
+ struct rte_mbuf *cur;
+ uint8_t alloc_err = 0;
+
+ desc = &vq->desc[head[entry_success]];
+
+ /* Discard first buffer as it is the virtio header */
+ desc = &vq->desc[desc->next];
+
+ /* Buffer address translation. */
+ vb_addr = gpa_to_vva(dev, desc->addr);
+ /* Prefetch buffer address. */
+ rte_prefetch0((void *)(uintptr_t)vb_addr);
+
+ used_idx = vq->last_used_idx & (vq->size - 1);
+
+ if (entry_success < (free_entries - 1)) {
+ /* Prefetch descriptor index. */
+ rte_prefetch0(&vq->desc[head[entry_success+1]]);
+ rte_prefetch0(&vq->used->ring[(used_idx + 1) & (vq->size - 1)]);
+ }
+
+ /* Update used index buffer information. */
+ vq->used->ring[used_idx].id = head[entry_success];
+ vq->used->ring[used_idx].len = 0;
+
+ vb_offset = 0;
+ vb_avail = desc->len;
+ /* Allocate an mbuf and populate the structure. */
+ m = rte_pktmbuf_alloc(mbuf_pool);
+ if (unlikely(m == NULL)) {
+ RTE_LOG(ERR, VHOST_DATA,
+ "Failed to allocate memory for mbuf.\n");
+ return entry_success;
+ }
+ seg_offset = 0;
+ seg_avail = m->buf_len - RTE_PKTMBUF_HEADROOM;
+ cpy_len = RTE_MIN(vb_avail, seg_avail);
+
+ PRINT_PACKET(dev, (uintptr_t)vb_addr, desc->len, 0);
+
+ seg_num++;
+ cur = m;
+ prev = m;
+ while (cpy_len != 0) {
+ rte_memcpy((void *)(rte_pktmbuf_mtod(cur, char *) + seg_offset),
+ (void *)((uintptr_t)(vb_addr + vb_offset)),
+ cpy_len);
+
+ seg_offset += cpy_len;
+ vb_offset += cpy_len;
+ vb_avail -= cpy_len;
+ seg_avail -= cpy_len;
+
+ if (vb_avail != 0) {
+ /*
+ * The segment reachs to its end,
+ * while the virtio buffer in TX vring has
+ * more data to be copied.
+ */
+ cur->data_len = seg_offset;
+ m->pkt_len += seg_offset;
+ /* Allocate mbuf and populate the structure. */
+ cur = rte_pktmbuf_alloc(mbuf_pool);
+ if (unlikely(cur == NULL)) {
+ RTE_LOG(ERR, VHOST_DATA, "Failed to "
+ "allocate memory for mbuf.\n");
+ rte_pktmbuf_free(m);
+ alloc_err = 1;
+ break;
+ }
+
+ seg_num++;
+ prev->next = cur;
+ prev = cur;
+ seg_offset = 0;
+ seg_avail = cur->buf_len - RTE_PKTMBUF_HEADROOM;
+ } else {
+ if (desc->flags & VRING_DESC_F_NEXT) {
+ /*
+ * There are more virtio buffers in
+ * same vring entry need to be copied.
+ */
+ if (seg_avail == 0) {
+ /*
+ * The current segment hasn't
+ * room to accomodate more
+ * data.
+ */
+ cur->data_len = seg_offset;
+ m->pkt_len += seg_offset;
+ /*
+ * Allocate an mbuf and
+ * populate the structure.
+ */
+ cur = rte_pktmbuf_alloc(mbuf_pool);
+ if (unlikely(cur == NULL)) {
+ RTE_LOG(ERR,
+ VHOST_DATA,
+ "Failed to "
+ "allocate memory "
+ "for mbuf\n");
+ rte_pktmbuf_free(m);
+ alloc_err = 1;
+ break;
+ }
+ seg_num++;
+ prev->next = cur;
+ prev = cur;
+ seg_offset = 0;
+ seg_avail = cur->buf_len - RTE_PKTMBUF_HEADROOM;
+ }
+
+ desc = &vq->desc[desc->next];
+
+ /* Buffer address translation. */
+ vb_addr = gpa_to_vva(dev, desc->addr);
+ /* Prefetch buffer address. */
+ rte_prefetch0((void *)(uintptr_t)vb_addr);
+ vb_offset = 0;
+ vb_avail = desc->len;
+
+ PRINT_PACKET(dev, (uintptr_t)vb_addr,
+ desc->len, 0);
+ } else {
+ /* The whole packet completes. */
+ cur->data_len = seg_offset;
+ m->pkt_len += seg_offset;
+ vb_avail = 0;
+ }
+ }
+
+ cpy_len = RTE_MIN(vb_avail, seg_avail);
+ }
+
+ if (unlikely(alloc_err == 1))
+ break;
+
+ m->nb_segs = seg_num;
+
+ pkts[entry_success] = m;
+ vq->last_used_idx++;
+ entry_success++;
+ }
+
+ rte_compiler_barrier();
+ vq->used->idx += entry_success;
+ /* Kick guest if required. */
+ if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT))
+ eventfd_write((int)vq->kickfd, 1);
+ return entry_success;
+}