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Diffstat (limited to 'examples/vhost/virtio_net.c')
| -rw-r--r-- | examples/vhost/virtio_net.c | 403 |
1 files changed, 403 insertions, 0 deletions
diff --git a/examples/vhost/virtio_net.c b/examples/vhost/virtio_net.c new file mode 100644 index 00000000..cc2c3d88 --- /dev/null +++ b/examples/vhost/virtio_net.c @@ -0,0 +1,403 @@ +/*- + * 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; +} |