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 <jfreim...@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; }
