net/virtio: support packed queue in send command

Use packed virtqueue format when reading and writing descriptors
to/from the ring.

Signed-off-by: Jens Freimann <jfreimann@redhat.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>

diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
index 7b32b29..d0c65e3 100644 (file)
--- a/drivers/net/virtio/virtio_ethdev.c
+++ b/drivers/net/virtio/virtio_ethdev.c
@@ -141,6 +141,96 @@ 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_packed_desc *desc = vq->ring_packed.desc_packed;
+       struct virtio_pmd_ctrl *result;
+       int wrap_counter;
+       uint16_t flags;
+       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];
+               flags = VRING_DESC_F_NEXT;
+               sum += dlen[k];
+               vq->vq_free_cnt--;
+               flags |= VRING_DESC_F_AVAIL(vq->avail_wrap_counter) |
+                        VRING_DESC_F_USED(!vq->avail_wrap_counter);
+               desc[vq->vq_avail_idx].flags = flags;
+               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);
+       flags = VRING_DESC_F_WRITE;
+       flags |= VRING_DESC_F_AVAIL(vq->avail_wrap_counter) |
+                VRING_DESC_F_USED(!vq->avail_wrap_counter);
+       desc[vq->vq_avail_idx].flags = flags;
+       flags = VRING_DESC_F_NEXT;
+       flags |= VRING_DESC_F_AVAIL(wrap_counter) |
+                VRING_DESC_F_USED(!wrap_counter);
+       desc[head].flags = flags;
+       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));
+
+       /* 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 +264,11 @@ 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 +340,7 @@ 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;
 }