static __rte_always_inline int
dequeue_pkt(struct vhost_rdma_net_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, desc_gaddr;
uint32_t desc_avail, desc_offset;
uint64_t desc_chunck_len;
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_chunck_len = desc->len;
desc_gaddr = desc->addr;
desc_addr = rte_vhost_va_from_guest_pa(
dev->mem, desc_gaddr, &desc_chunck_len);
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_chunck_len = desc->len;
desc_gaddr = desc->addr;
desc_addr = rte_vhost_va_from_guest_pa(
dev->mem, desc_gaddr, &desc_chunck_len);
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_chunck_len, 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;
desc_chunck_len -= 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_chunck_len = desc->len;
desc_gaddr = desc->addr;
desc_addr = rte_vhost_va_from_guest_pa(
dev->mem, desc_gaddr, &desc_chunck_len);
if (unlikely(!desc_addr))
return -1;
rte_prefetch0((void *)(uintptr_t)desc_addr);
desc_offset = 0;
desc_avail = desc->len;
} else if (unlikely(desc_chunck_len == 0)) {
desc_chunck_len = desc_avail;
desc_gaddr += desc_offset;
desc_addr = rte_vhost_va_from_guest_pa(dev->mem,
desc_gaddr,
&desc_chunck_len);
if (unlikely(!desc_addr))
return -1;
desc_offset = 0;
}
/*
* 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)) {
RDMA_LOG_ERR("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;
}
static __rte_always_inline int
enqueue_pkt(struct vhost_rdma_net_dev *dev,
struct rte_vhost_vring *vr,
struct rte_mbuf *m,
uint16_t desc_idx)
{
uint32_t desc_avail, desc_offset;
uint64_t desc_chunck_len;
uint32_t mbuf_avail, mbuf_offset;
uint32_t cpy_len;
struct vring_desc *desc;
uint64_t desc_addr, desc_gaddr;
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_chunck_len = desc->len;
desc_gaddr = desc->addr;
desc_addr = rte_vhost_va_from_guest_pa(
dev->mem, desc_gaddr, &desc_chunck_len);
/*
* 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 */
if (likely(desc_chunck_len >= dev->hdr_len)) {
*(struct virtio_net_hdr *)(uintptr_t)desc_addr = virtio_hdr;
desc_offset = dev->hdr_len;
} else {
uint64_t len;
uint64_t remain = dev->hdr_len;
uint64_t src = (uint64_t)(uintptr_t)&virtio_hdr, dst;
uint64_t guest_addr = desc_gaddr;
while (remain) {
len = remain;
dst = rte_vhost_va_from_guest_pa(dev->mem,
guest_addr, &len);
if (unlikely(!dst || !len))
return -1;
rte_memcpy((void *)(uintptr_t)dst,
(void *)(uintptr_t)src,
len);
remain -= len;
guest_addr += len;
src += len;
}
desc_chunck_len = desc->len - dev->hdr_len;
desc_gaddr += dev->hdr_len;
desc_addr = rte_vhost_va_from_guest_pa(
dev->mem, desc_gaddr,
&desc_chunck_len);
if (unlikely(!desc_addr))
return -1;
desc_offset = 0;
}
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_chunck_len = desc->len;
desc_gaddr = desc->addr;
desc_addr = rte_vhost_va_from_guest_pa(
dev->mem, desc_gaddr, &desc_chunck_len);
if (unlikely(!desc_addr))
return -1;
desc_offset = 0;
desc_avail = desc->len;
} else if (unlikely(desc_chunck_len == 0)) {
desc_chunck_len = desc_avail;
desc_gaddr += desc_offset;
desc_addr = rte_vhost_va_from_guest_pa(dev->mem,
desc_gaddr,
&desc_chunck_len);
if (unlikely(!desc_addr))
return -1;
desc_offset = 0;
}
cpy_len = RTE_MIN(desc_chunck_len, 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;
desc_chunck_len -= cpy_len;
}
return 0;
}
uint16_t
vhost_rdma_dequeue_pkts(uint16_t queue_id,
struct rte_mempool *mbuf_pool,
struct rte_mbuf **pkts,
uint16_t count)
{
struct vhost_rdma_net_dev *dev = &g_vhost_rdma_net_dev[0];
struct vhost_user_queue *queue;
struct rte_vhost_vring *vr;
uint16_t avail_idx, free_entries, start_idx;
uint16_t desc_indexes[MAX_PKTS_BURST];
uint16_t used_idx;
uint32_t i;
if (!dev->started)
return 0;
assert(queue_id == VHOST_NET_RXQ);
queue = &dev->queues[queue_id];
vr = &queue->vring;
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_PKTS_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;
}
/* 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)) {
RDMA_LOG_ERR("Failed to allocate memory for mbuf");
break;
}
err = dequeue_pkt(dev, vr, pkts[i], desc_indexes[i], mbuf_pool);
if (unlikely(err)) {
rte_pktmbuf_free(pkts[i]);
break;
}
}
queue->last_avail_idx += i;
queue->last_used_idx += i;
rte_smp_wmb();
rte_smp_rmb();
vr->used->idx += i;
rte_vhost_vring_call(dev->vid, queue_id);
return i;
}
uint16_t
vhost_rdma_enqueue_pkts(uint16_t queue_id,
struct rte_mbuf **pkts,
uint32_t count)
{
struct vhost_rdma_net_dev *dev = &g_vhost_rdma_net_dev[0];
struct vhost_user_queue *queue;
struct rte_vhost_vring *vr;
uint16_t avail_idx, free_entries, start_idx;
uint16_t desc_indexes[MAX_PKTS_BURST];
uint16_t used_idx;
uint32_t i;
if (!dev->started)
return 0;
assert(queue_id == VHOST_NET_RXQ);
queue = &dev->queues[queue_id];
vr = &queue->vring;
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_PKTS_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;
rte_vhost_vring_call(dev->vid, queue_id);
return count;
}为这段代码 写一段dpdk commit 信息