[dpdk-dev] [PATCH v9 5/8] net/virtio: implement transmit path for packed queues
Tiwei Bie
tiwei.bie at intel.com
Thu Oct 25 11:31:04 CEST 2018
On Wed, Oct 24, 2018 at 04:32:33PM +0200, Jens Freimann wrote:
> This implements the transmit path for devices with
> support for packed virtqueues.
>
> Signed-off-by: Jens Freiman <jfreimann at redhat.com>
> ---
> drivers/net/virtio/virtio_ethdev.c | 32 +++-
> drivers/net/virtio/virtio_ethdev.h | 2 +
> drivers/net/virtio/virtio_rxtx.c | 284 +++++++++++++++++++++++++++++
> drivers/net/virtio/virtqueue.h | 18 +-
> 4 files changed, 324 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
> index 6130aef16..d2118e6a9 100644
> --- a/drivers/net/virtio/virtio_ethdev.c
> +++ b/drivers/net/virtio/virtio_ethdev.c
> @@ -384,6 +384,8 @@ virtio_init_queue(struct rte_eth_dev *dev, uint16_t vtpci_queue_idx)
> vq->hw = hw;
> vq->vq_queue_index = vtpci_queue_idx;
> vq->vq_nentries = vq_size;
> + if (vtpci_packed_queue(hw))
> + vq->vq_ring.avail_wrap_counter = 1;
>
> /*
> * Reserve a memzone for vring elements
> @@ -490,16 +492,22 @@ virtio_init_queue(struct rte_eth_dev *dev, uint16_t vtpci_queue_idx)
> memset(txr, 0, vq_size * sizeof(*txr));
> for (i = 0; i < vq_size; i++) {
> struct vring_desc *start_dp = txr[i].tx_indir;
> -
> - vring_desc_init_split(start_dp, RTE_DIM(txr[i].tx_indir));
> -
> + struct vring_desc_packed*start_dp_packed = txr[i].tx_indir_pq;
A space is missing before *start_dp_packed
> +
> /* first indirect descriptor is always the tx header */
> - start_dp->addr = txvq->virtio_net_hdr_mem
> - + i * sizeof(*txr)
> - + offsetof(struct virtio_tx_region, tx_hdr);
> -
> - start_dp->len = hw->vtnet_hdr_size;
> - start_dp->flags = VRING_DESC_F_NEXT;
> + if (vtpci_packed_queue(hw)) {
> + start_dp_packed->addr = txvq->virtio_net_hdr_mem
> + + i * sizeof(*txr)
> + + offsetof(struct virtio_tx_region, tx_hdr);
> + start_dp_packed->len = hw->vtnet_hdr_size;
> + } else {
> + vring_desc_init_split(start_dp, RTE_DIM(txr[i].tx_indir));
> + start_dp->addr = txvq->virtio_net_hdr_mem
> + + i * sizeof(*txr)
> + + offsetof(struct virtio_tx_region, tx_hdr);
> + start_dp->len = hw->vtnet_hdr_size;
> + start_dp->flags = VRING_DESC_F_NEXT;
> + }
> }
> }
>
> @@ -1338,7 +1346,11 @@ set_rxtx_funcs(struct rte_eth_dev *eth_dev)
> eth_dev->rx_pkt_burst = &virtio_recv_pkts;
> }
>
> - if (hw->use_inorder_tx) {
> + if (vtpci_packed_queue(hw)) {
> + PMD_INIT_LOG(INFO, "virtio: using virtio 1.1 Tx path on port %u",
> + eth_dev->data->port_id);
> + eth_dev->tx_pkt_burst = virtio_xmit_pkts_packed;
> + } else if (hw->use_inorder_tx) {
Please make the structure more clear, e.g. something like:
if (vtpci_packed_queue(hw)) {
// packed ring
} else {
// split ring
}
> PMD_INIT_LOG(INFO, "virtio: using inorder Tx path on port %u",
> eth_dev->data->port_id);
> eth_dev->tx_pkt_burst = virtio_xmit_pkts_inorder;
> diff --git a/drivers/net/virtio/virtio_ethdev.h b/drivers/net/virtio/virtio_ethdev.h
> index e0f80e5a4..05d355180 100644
> --- a/drivers/net/virtio/virtio_ethdev.h
> +++ b/drivers/net/virtio/virtio_ethdev.h
> @@ -82,6 +82,8 @@ uint16_t virtio_recv_mergeable_pkts_inorder(void *rx_queue,
>
> uint16_t virtio_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
> uint16_t nb_pkts);
> +uint16_t virtio_xmit_pkts_packed(void *tx_queue, struct rte_mbuf **tx_pkts,
> + uint16_t nb_pkts);
>
> uint16_t virtio_xmit_pkts_inorder(void *tx_queue, struct rte_mbuf **tx_pkts,
> uint16_t nb_pkts);
> diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c
> index eb891433e..837457243 100644
> --- a/drivers/net/virtio/virtio_rxtx.c
> +++ b/drivers/net/virtio/virtio_rxtx.c
> @@ -88,6 +88,42 @@ vq_ring_free_chain(struct virtqueue *vq, uint16_t desc_idx)
> dp->next = VQ_RING_DESC_CHAIN_END;
> }
>
> +void
> +vq_ring_free_chain_packed(struct virtqueue *vq, uint16_t desc_idx, used_idx)
Does above code pass the build test? (Type is missing for used_idx)
> +{
> + struct vring_desc_packed *dp;
> + struct vq_desc_extra *dxp = NULL, *dxp_tail = NULL;
Do we really need to initialize them?
> + uint16_t desc_idx_last = desc_idx;
> + int i = 0;
> +
> + dp = &vq->vq_ring.desc_packed[used_idx];
> + dxp = &vq->vq_descx[desc_idx];
> + vq->vq_free_cnt = (uint16_t)(vq->vq_free_cnt + dxp->ndescs);
> + if ((dp->flags & VRING_DESC_F_INDIRECT) == 0) {
> + while (dp->flags & VRING_DESC_F_NEXT && i < dxp->ndescs) {
NEXT can't be used here.
> + desc_idx_last = dxp->next;
> + dp = &vq->vq_ring.desc_packed[dxp->next];
dxp->next is used to link the dxps, it's not supposed to
be desc ring's index.
> + dxp = &vq->vq_descx[dxp->next];
> + i++;
> + }
> + }
> +
> + /*
> + * We must append the existing free chain, if any, to the end of
> + * newly freed chain. If the virtqueue was completely used, then
> + * head would be VQ_RING_DESC_CHAIN_END (ASSERTed above).
> + */
> + if (vq->vq_desc_tail_idx == VQ_RING_DESC_CHAIN_END) {
> + vq->vq_desc_head_idx = desc_idx;
> + } else {
> + dxp_tail = &vq->vq_descx[vq->vq_desc_tail_idx];
> + dxp_tail->next = desc_idx;
> + }
> +
> + vq->vq_desc_tail_idx = desc_idx_last;
> + dxp->next = VQ_RING_DESC_CHAIN_END;
> +}
> +
> static uint16_t
> virtqueue_dequeue_burst_rx(struct virtqueue *vq, struct rte_mbuf **rx_pkts,
> uint32_t *len, uint16_t num)
> @@ -165,6 +201,33 @@ virtqueue_dequeue_rx_inorder(struct virtqueue *vq,
> #endif
>
> /* Cleanup from completed transmits. */
> +static void
> +virtio_xmit_cleanup_packed(struct virtqueue *vq, int num)
> +{
> + uint16_t used_idx, id;
> + uint16_t size = vq->vq_nentries;
> + struct vring_desc_packed *desc = vq->vq_ring.desc_packed;
> + struct vq_desc_extra *dxp;
> +
> + used_idx = vq->vq_used_cons_idx;
> + while (num && desc_is_used(&desc[used_idx], &vq->vq_ring)) {
> + num --;
> + used_idx = vq->vq_used_cons_idx;
> + id = desc[used_idx].index;
> + dxp = &vq->vq_descx[id];
> + if (++vq->vq_used_cons_idx >= size) {
We need to skip dxp->ndescs descriptors here.
> + vq->vq_used_cons_idx -= size;
> + vq->vq_ring.used_wrap_counter ^= 1;
> + }
> + vq_ring_free_chain_packed(vq, id, used_idx);
> + if (dxp->cookie != NULL) {
> + rte_pktmbuf_free(dxp->cookie);
> + dxp->cookie = NULL;
> + }
> + used_idx = vq->vq_used_cons_idx;
> + }
> +}
> +
> static void
> virtio_xmit_cleanup(struct virtqueue *vq, uint16_t num)
> {
> @@ -456,6 +519,134 @@ virtqueue_enqueue_xmit_inorder(struct virtnet_tx *txvq,
> vq->vq_desc_head_idx = idx & (vq->vq_nentries - 1);
> }
>
> +static inline void
> +virtqueue_enqueue_xmit_packed(struct virtnet_tx *txvq, struct rte_mbuf *cookie,
> + uint16_t needed, int use_indirect, int can_push,
> + int in_order)
> +{
> + struct virtio_tx_region *txr = txvq->virtio_net_hdr_mz->addr;
> + struct vq_desc_extra *dxp, *head_dxp;
> + struct virtqueue *vq = txvq->vq;
> + struct vring_desc_packed *start_dp, *head_dp;
> + uint16_t seg_num = cookie->nb_segs;
> + uint16_t idx, head_id, head_flags;
> + uint16_t head_size = vq->hw->vtnet_hdr_size;
> + struct virtio_net_hdr *hdr;
> + uint16_t prev;
> +
> + head_id = vq->vq_desc_head_idx;
> + idx = head_id;
> + prev = idx;
> + start_dp = vq->vq_ring.desc_packed;
> + dxp = &vq->vq_descx[idx];
> + dxp->ndescs = needed;
> +
> + head_dp = &vq->vq_ring.desc_packed[head_id];
> + head_dxp = &vq->vq_descx[head_id];
I don't think desc and descx can always have the same index.
> + head_dxp->cookie = (void *) cookie;
> + head_flags = cookie->next ? VRING_DESC_F_NEXT: 0;
> + head_flags |= VRING_DESC_F_AVAIL(vq->vq_ring.avail_wrap_counter) |
> + VRING_DESC_F_USED(!vq->vq_ring.avail_wrap_counter);
> +
[...]
>
> +static inline int
> +virtqueue_kick_prepare_packed(struct virtqueue *vq)
> +{
> + uint16_t flags;
> +
> + flags = vq->vq_ring.device_event->desc_event_flags & RING_EVENT_FLAGS_DESC;
We can't "& RING_EVENT_FLAGS_DESC" here.
> + return (flags != RING_EVENT_FLAGS_DISABLE);
> +}
> +
> static inline void
> virtqueue_notify(struct virtqueue *vq)
> {
> --
> 2.17.1
>
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