[dpdk-dev] [PATCH v10 7/9] net/virtio: add virtio send command packed queue support
Maxime Coquelin
maxime.coquelin at redhat.com
Wed Nov 28 18:25:49 CET 2018
On 11/2/18 10:07 AM, Jens Freimann wrote:
> Use packed virtqueue format when reading and writing descriptors
> to/from the ring.
>
> Signed-off-by: Jens Freimann <jfreimann at redhat.com>
> ---
> drivers/net/virtio/virtio_ethdev.c | 90 ++++++++++++++++++++++++++++++
> 1 file changed, 90 insertions(+)
>
> diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
> index ed3d5bd2c..4451dd49b 100644
> --- a/drivers/net/virtio/virtio_ethdev.c
> +++ b/drivers/net/virtio/virtio_ethdev.c
> @@ -141,6 +141,90 @@ static const struct rte_virtio_xstats_name_off rte_virtio_txq_stat_strings[] = {
>
> struct virtio_hw_internal virtio_hw_internal[RTE_MAX_ETHPORTS];
>
> +static struct virtio_pmd_ctrl *
> +virtio_pq_send_command(struct virtnet_ctl *cvq, struct virtio_pmd_ctrl *ctrl,
> + int *dlen, int pkt_num)
> +{
> + struct virtqueue *vq = cvq->vq;
> + int head;
> + struct vring_desc_packed *desc = vq->ring_packed.desc_packed;
> + struct virtio_pmd_ctrl *result;
> + int wrap_counter;
> + int sum = 0;
> + int k;
> +
> + /*
> + * Format is enforced in qemu code:
> + * One TX packet for header;
> + * At least one TX packet per argument;
> + * One RX packet for ACK.
> + */
> + head = vq->vq_avail_idx;
> + wrap_counter = vq->avail_wrap_counter;
> + desc[head].flags = VRING_DESC_F_NEXT;
> + desc[head].addr = cvq->virtio_net_hdr_mem;
> + desc[head].len = sizeof(struct virtio_net_ctrl_hdr);
> + vq->vq_free_cnt--;
> + if (++vq->vq_avail_idx >= vq->vq_nentries) {
> + vq->vq_avail_idx -= vq->vq_nentries;
> + vq->avail_wrap_counter ^= 1;
> + }
> +
> + for (k = 0; k < pkt_num; k++) {
> + desc[vq->vq_avail_idx].addr = cvq->virtio_net_hdr_mem
> + + sizeof(struct virtio_net_ctrl_hdr)
> + + sizeof(ctrl->status) + sizeof(uint8_t) * sum;
> + desc[vq->vq_avail_idx].len = dlen[k];
> + desc[vq->vq_avail_idx].flags = VRING_DESC_F_NEXT;
> + sum += dlen[k];
> + vq->vq_free_cnt--;
> + _set_desc_avail(&desc[vq->vq_avail_idx],
> + vq->avail_wrap_counter);
> + rte_smp_wmb();
> + vq->vq_free_cnt--;
> + if (++vq->vq_avail_idx >= vq->vq_nentries) {
> + vq->vq_avail_idx -= vq->vq_nentries;
> + vq->avail_wrap_counter ^= 1;
> + }
> + }
> +
> +
> + desc[vq->vq_avail_idx].addr = cvq->virtio_net_hdr_mem
> + + sizeof(struct virtio_net_ctrl_hdr);
> + desc[vq->vq_avail_idx].len = sizeof(ctrl->status);
> + desc[vq->vq_avail_idx].flags = VRING_DESC_F_WRITE;
> + _set_desc_avail(&desc[vq->vq_avail_idx],
> + vq->avail_wrap_counter);
> + _set_desc_avail(&desc[head], wrap_counter);
> + rte_smp_wmb();
> +
> + vq->vq_free_cnt--;
> + if (++vq->vq_avail_idx >= vq->vq_nentries) {
> + vq->vq_avail_idx -= vq->vq_nentries;
> + vq->avail_wrap_counter ^= 1;
> + }
> +
> + virtqueue_notify(vq);
> +
> + /* wait for used descriptors in virtqueue */
> + do {
> + rte_rmb();
> + usleep(100);
> + } while (!desc_is_used(&desc[head], vq));
Maybe better to poll for !desc_is_used(&desc[vq->vq_used_cons_idx], vq))
to make it clear we're safe using used_wrap_counter?
> +
> + /* now get used descriptors */
> + while(desc_is_used(&desc[vq->vq_used_cons_idx], vq)) {
> + vq->vq_free_cnt++;
> + if (++vq->vq_used_cons_idx >= vq->vq_nentries) {
> + vq->vq_used_cons_idx -= vq->vq_nentries;
> + vq->used_wrap_counter ^= 1;
> + }
> + }
> +
> + result = cvq->virtio_net_hdr_mz->addr;
> + return result;
> +}
> +
> static int
> virtio_send_command(struct virtnet_ctl *cvq, struct virtio_pmd_ctrl *ctrl,
> int *dlen, int pkt_num)
> @@ -174,6 +258,11 @@ virtio_send_command(struct virtnet_ctl *cvq, struct virtio_pmd_ctrl *ctrl,
> memcpy(cvq->virtio_net_hdr_mz->addr, ctrl,
> sizeof(struct virtio_pmd_ctrl));
>
> + if (vtpci_packed_queue(vq->hw)) {
> + result = virtio_pq_send_command(cvq, ctrl, dlen, pkt_num);
> + goto out_unlock;
> + }
> +
> /*
> * Format is enforced in qemu code:
> * One TX packet for header;
> @@ -245,6 +334,7 @@ virtio_send_command(struct virtnet_ctl *cvq, struct virtio_pmd_ctrl *ctrl,
>
> result = cvq->virtio_net_hdr_mz->addr;
>
> +out_unlock:
> rte_spinlock_unlock(&cvq->lock);
> return result->status;
> }
>
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