[dpdk-dev] [PATCH v3 19/21] vhost: support mergeable rx buffers with packed queues
Jens Freimann
jfreimann at redhat.com
Fri Apr 6 16:07:17 CEST 2018
On Fri, Apr 06, 2018 at 03:04:47PM +0200, Maxime Coquelin wrote:
>
>
>On 04/05/2018 12:10 PM, Jens Freimann wrote:
>>This implements support for mergeable receive buffers in vhost when using
>>packed virtqueues. The difference to split virtqueues is not big, it differs
>>mostly where descriptor flags are touched and virtio features are checked.
>>
>>Signed-off-by: Jens Freimann <jfreimann at redhat.com>
>>---
>> lib/librte_vhost/vhost.c | 2 +
>> lib/librte_vhost/virtio_net.c | 160 +++++++++++++++++++++++++++++++++---------
>> 2 files changed, 127 insertions(+), 35 deletions(-)
>>
>>diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c
>>index eb5a98875..3c633e71e 100644
>>--- a/lib/librte_vhost/vhost.c
>>+++ b/lib/librte_vhost/vhost.c
>>@@ -580,6 +580,8 @@ rte_vhost_enable_guest_notification(int vid, uint16_t queue_id, int enable)
>> if (dev == NULL)
>> return -1;
>>+ if (dev->features & (1ULL << VIRTIO_F_RING_PACKED))
>>+ return -1;
>
>Is this change really related to mergeable buffers?
no, will fix
>
>> if (enable) {
>> RTE_LOG(ERR, VHOST_CONFIG,
>>diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
>>index 18e67fdc1..b82c24081 100644
>>--- a/lib/librte_vhost/virtio_net.c
>>+++ b/lib/librte_vhost/virtio_net.c
>>@@ -401,17 +401,53 @@ virtio_dev_rx(struct virtio_net *dev, uint16_t queue_id,
>> }
>> static __rte_always_inline int
>>-fill_vec_buf(struct virtio_net *dev, struct vhost_virtqueue *vq,
>>- uint32_t avail_idx, uint32_t *vec_idx,
>>- struct buf_vector *buf_vec, uint16_t *desc_chain_head,
>>- uint16_t *desc_chain_len)
>>+__fill_vec_buf_packed(struct virtio_net *dev, struct vhost_virtqueue *vq,
>>+ struct buf_vector *buf_vec,
>>+ uint32_t *len, uint32_t *vec_id)
>>+{
>>+ uint16_t idx = vq->last_avail_idx & (vq->size - 1);
>>+ struct vring_desc_packed *descs= vq->desc_packed;
>>+ uint32_t _vec_id = *vec_id;
>>+
>>+ if (vq->desc_packed[idx].flags & VRING_DESC_F_INDIRECT) {
>>+ descs = (struct vring_desc_packed *)(uintptr_t)
>>+ vhost_iova_to_vva(dev, vq, vq->desc_packed[idx].addr,
>>+ vq->desc_packed[idx].len,
>>+ VHOST_ACCESS_RO);
>>+ if (unlikely(!descs))
>>+ return -1;
>>+
>>+ idx = 0;
>>+ }
>>+
>>+ while (1) {
>>+ if (unlikely(_vec_id >= BUF_VECTOR_MAX || idx >= vq->size))
>>+ return -1;
>>+
>>+ *len += descs[idx & (vq->size - 1)].len;
>>+ buf_vec[_vec_id].buf_addr = descs[idx].addr;
>>+ buf_vec[_vec_id].buf_len = descs[idx].len;
>>+ buf_vec[_vec_id].desc_idx = idx;
>>+ _vec_id++;
>>+
>>+ if ((descs[idx & (vq->size - 1)].flags & VRING_DESC_F_NEXT) == 0)
>>+ break;
>>+
>>+ idx++;
>>+ }
>>+ *vec_id = _vec_id;
>>+
>>+ return 0;
>>+}
>>+
>>+static __rte_always_inline int
>>+__fill_vec_buf_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
>>+ struct buf_vector *buf_vec,
>>+ uint32_t *len, uint32_t *vec_id, uint32_t avail_idx)
>> {
>> uint16_t idx = vq->avail->ring[avail_idx & (vq->size - 1)];
>>- uint32_t vec_id = *vec_idx;
>>- uint32_t len = 0;
>> struct vring_desc *descs = vq->desc;
>>-
>>- *desc_chain_head = idx;
>>+ uint32_t _vec_id = *vec_id;
>> if (vq->desc[idx].flags & VRING_DESC_F_INDIRECT) {
>> descs = (struct vring_desc *)(uintptr_t)
>>@@ -425,20 +461,53 @@ fill_vec_buf(struct virtio_net *dev, struct vhost_virtqueue *vq,
>> }
>> while (1) {
>>- if (unlikely(vec_id >= BUF_VECTOR_MAX || idx >= vq->size))
>>+ if (unlikely(_vec_id >= BUF_VECTOR_MAX || idx >= vq->size))
>> return -1;
>>- len += descs[idx].len;
>>- buf_vec[vec_id].buf_addr = descs[idx].addr;
>>- buf_vec[vec_id].buf_len = descs[idx].len;
>>- buf_vec[vec_id].desc_idx = idx;
>>- vec_id++;
>>+ *len += descs[idx].len;
>>+ buf_vec[_vec_id].buf_addr = descs[idx].addr;
>>+ buf_vec[_vec_id].buf_len = descs[idx].len;
>>+ buf_vec[_vec_id].desc_idx = idx;
>>+ _vec_id++;
>> if ((descs[idx].flags & VRING_DESC_F_NEXT) == 0)
>> break;
>> idx = descs[idx].next;
>> }
>>+ *vec_id = _vec_id;
>>+
>>+ return 0;
>>+}
>>+
>>+static __rte_always_inline int
>>+fill_vec_buf(struct virtio_net *dev, struct vhost_virtqueue *vq,
>>+ uint32_t avail_idx, uint32_t *vec_idx,
>>+ struct buf_vector *buf_vec, uint16_t *desc_chain_head,
>>+ uint16_t *desc_chain_len)
>>+{
>>+ uint16_t idx;
>>+ uint32_t vec_id = *vec_idx;
>>+ uint32_t len = 0;
>>+
>>+ if (dev->features & (1ULL << VIRTIO_F_RING_PACKED)) {
>>+ idx = vq->last_avail_idx & (vq->size -1);
>>+ } else {
>>+ idx = vq->avail->ring[avail_idx & (vq->size - 1)];
>>+ }
>>+
>>+
>>+ *desc_chain_head = idx;
>>+
>>+ if (dev->features & (1ULL << VIRTIO_F_RING_PACKED)) {
>>+ if (__fill_vec_buf_packed(dev, vq,
>>+ buf_vec, &len, &vec_id))
>>+ return -1;
>>+ } else {
>>+ if (__fill_vec_buf_split(dev, vq,
>>+ buf_vec, &len, &vec_id, avail_idx))
>>+ return -1;
>>+ }
>> *desc_chain_len = len;
>> *vec_idx = vec_id;
>>@@ -465,14 +534,16 @@ reserve_avail_buf_mergeable(struct virtio_net *dev, struct vhost_virtqueue *vq,
>> cur_idx = vq->last_avail_idx;
>> while (size > 0) {
>>- if (unlikely(cur_idx == avail_head))
>>+ if (unlikely(cur_idx == avail_head) &&
>>+ !(dev->features & (1ull < VIRTIO_F_RING_PACKED)))
>> return -1;
>> if (unlikely(fill_vec_buf(dev, vq, cur_idx, &vec_idx, buf_vec,
>> &head_idx, &len) < 0))
>> return -1;
>> len = RTE_MIN(len, size);
>>- update_shadow_used_ring(vq, head_idx, len);
>>+ if (!(dev->features & (1ULL << VIRTIO_F_RING_PACKED)))
>
>This is cosmetics, but I wonder if we could have a helper like:
>
>static inline bool
>vring_is_packed(struct virtio_net *dev) {
> return dev->features & (1ULL << VIRTIO_F_RING_PACKED);
>}
Yes, I will add one
>
>>+ update_shadow_used_ring(vq, head_idx, len);
>> size -= len;
>> cur_idx++;
>>@@ -620,6 +691,8 @@ virtio_dev_merge_rx(struct virtio_net *dev, uint16_t queue_id,
>> uint16_t num_buffers;
>> struct buf_vector buf_vec[BUF_VECTOR_MAX];
>> uint16_t avail_head;
>>+ uint16_t i;
>>+ struct vring_desc_packed *descs = NULL;
>> VHOST_LOG_DEBUG(VHOST_DATA, "(%d) %s\n", dev->vid, __func__);
>> if (unlikely(!is_valid_virt_queue_idx(queue_id, 0, dev->nr_vring))) {
>>@@ -634,7 +707,6 @@ virtio_dev_merge_rx(struct virtio_net *dev, uint16_t queue_id,
>> if (unlikely(vq->enabled == 0))
>> goto out_access_unlock;
>>-
>> if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
>> vhost_user_iotlb_rd_lock(vq);
>>@@ -648,10 +720,14 @@ virtio_dev_merge_rx(struct virtio_net *dev, uint16_t queue_id,
>> vq->batch_copy_nb_elems = 0;
>>- rte_prefetch0(&vq->avail->ring[vq->last_avail_idx & (vq->size - 1)]);
>>-
>>- vq->shadow_used_idx = 0;
>>- avail_head = *((volatile uint16_t *)&vq->avail->idx);
>>+ if (dev->features & (1ULL << VIRTIO_F_RING_PACKED)) {
>>+ avail_head = vq->last_avail_idx;
>>+ descs = vq->desc_packed;
>>+ } else {
>>+ rte_prefetch0(&vq->avail->ring[vq->last_avail_idx & (vq->size - 1)]);
>>+ avail_head = *((volatile uint16_t *)&vq->avail->idx);
>>+ vq->shadow_used_idx = 0;
>>+ }
>> for (pkt_idx = 0; pkt_idx < count; pkt_idx++) {
>> uint32_t pkt_len = pkts[pkt_idx]->pkt_len + dev->vhost_hlen;
>>@@ -661,7 +737,9 @@ virtio_dev_merge_rx(struct virtio_net *dev, uint16_t queue_id,
>> VHOST_LOG_DEBUG(VHOST_DATA,
>> "(%d) failed to get enough desc from vring\n",
>> dev->vid);
>>- vq->shadow_used_idx -= num_buffers;
>>+
>>+ if (!dev->features & (1ULL & VIRTIO_F_RING_PACKED))
>>+ vq->shadow_used_idx -= num_buffers;
>> break;
>> }
>>@@ -671,7 +749,8 @@ virtio_dev_merge_rx(struct virtio_net *dev, uint16_t queue_id,
>> if (copy_mbuf_to_desc_mergeable(dev, vq, pkts[pkt_idx],
>> buf_vec, num_buffers) < 0) {
>>- vq->shadow_used_idx -= num_buffers;
>>+ if (!dev->features & (1ULL & VIRTIO_F_RING_PACKED))
>>+ vq->shadow_used_idx -= num_buffers;
>> break;
>> }
>>@@ -680,9 +759,18 @@ virtio_dev_merge_rx(struct virtio_net *dev, uint16_t queue_id,
>> do_data_copy_enqueue(dev, vq);
>>- if (likely(vq->shadow_used_idx)) {
>>- flush_shadow_used_ring(dev, vq);
>>- vhost_vring_call(dev, vq);
>>+ if (!(dev->features & (1ULL << VIRTIO_F_RING_PACKED))) {
>>+ if (likely(vq->shadow_used_idx)) {
>>+ flush_shadow_used_ring(dev, vq);
>>+ vhost_vring_call(dev, vq);
>>+ }
>>+ } else {
>>+ rte_smp_wmb();
>>+ for (i = avail_head; i < vq->last_avail_idx; i++) {
>>+ if ((i & (vq->size - 1)) == 0)
>>+ toggle_wrap_counter(vq);
>>+ set_desc_used(vq, &descs[i & (vq->size - 1)]);
>>+ }
>> }
>> out:
>>@@ -774,7 +862,7 @@ vhost_enqueue_burst_packed(struct virtio_net *dev, uint16_t queue_id,
>> goto out;
>> }
>>- idx = (idx+1) & (vq->size - 1);
>>+ idx = (idx + 1) & mask;
>Are you sure this change is in the right patch?
Pretty sure it's not :)
>
>> desc = &descs[idx];
>> if (unlikely(!desc_is_avail(vq, desc)))
>> goto out ;
>>@@ -840,10 +928,11 @@ rte_vhost_enqueue_burst(int vid, uint16_t queue_id,
>> return 0;
>> }
>>- if (dev->features & (1ULL << VIRTIO_F_RING_PACKED))
>>- return vhost_enqueue_burst_packed(dev, queue_id, pkts, count);
>>- else if (dev->features & (1 << VIRTIO_NET_F_MRG_RXBUF))
>>+ if ((dev->features & (1 << VIRTIO_NET_F_MRG_RXBUF)) &&
>>+ (dev->features & (1ULL << VIRTIO_F_RING_PACKED)))
>> return virtio_dev_merge_rx(dev, queue_id, pkts, count);
>>+ else if (dev->features & (1ULL << VIRTIO_F_RING_PACKED))
>>+ return vhost_enqueue_burst_packed(dev, queue_id, pkts, count);
>> else
>> return virtio_dev_rx(dev, queue_id, pkts, count);
>> }
>>@@ -1266,8 +1355,6 @@ dequeue_desc_packed(struct virtio_net *dev, struct vhost_virtqueue *vq,
>> int wrap_counter = vq->used_wrap_counter;
>> int rc = 0;
>>- rte_spinlock_lock(&vq->access_lock);
>>-
>hmm
>
>> if (unlikely(vq->enabled == 0))
>> goto out;
>>@@ -1451,6 +1538,9 @@ vhost_dequeue_burst_packed(struct virtio_net *dev, struct vhost_virtqueue *vq,
>> struct vring_desc_packed *desc = vq->desc_packed;
>> int err;
>>+ if (unlikely(rte_spinlock_trylock(&vq->access_lock) == 0))
>>+ return 0;
>>+
>> count = RTE_MIN(MAX_PKT_BURST, count);
>> for (i = 0; i < count; i++) {
>> idx = vq->last_used_idx & (vq->size - 1);
>>@@ -1509,15 +1599,15 @@ rte_vhost_dequeue_burst(int vid, uint16_t queue_id,
>> vq = dev->virtqueue[queue_id];
>>+ if (dev->features & (1ULL << VIRTIO_F_RING_PACKED))
>>+ return vhost_dequeue_burst_packed(dev, vq, mbuf_pool, pkts, count);
>>+
>> if (unlikely(rte_spinlock_trylock(&vq->access_lock) == 0))
>> return 0;
>> if (unlikely(vq->enabled == 0))
>> goto out_access_unlock;
>>- if (dev->features & (1ULL << VIRTIO_F_RING_PACKED))
>>- return vhost_dequeue_burst_packed(dev, vq, mbuf_pool, pkts, count);
>>-
>> vq->batch_copy_nb_elems = 0;
>> if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
>>
>
>all above changes, if valid, are for dequeue, so 'tx', so certainly in
>the wrong patch.
yes, I'll move them. Thanks!
regards,
Jens
More information about the dev
mailing list