[dpdk-dev] [PATCH v7 5/8] net/virtio: implement transmit path for packed queues
Jens Freimann
jfreimann at redhat.com
Wed Oct 3 15:11:15 CEST 2018
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_ring.h | 15 +-
drivers/net/virtio/virtio_rxtx.c | 276 +++++++++++++++++++++++++++++
drivers/net/virtio/virtqueue.h | 18 +-
5 files changed, 329 insertions(+), 14 deletions(-)
diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
index d6a1613dd..c65ac365c 100644
--- a/drivers/net/virtio/virtio_ethdev.c
+++ b/drivers/net/virtio/virtio_ethdev.c
@@ -390,6 +390,8 @@ 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
@@ -496,16 +498,22 @@ 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;
+
/* 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;
+ }
}
}
@@ -1344,7 +1352,11 @@ 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) {
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_ring.h b/drivers/net/virtio/virtio_ring.h
index b9e63d4d4..dbffd4dcd 100644
--- a/drivers/net/virtio/virtio_ring.h
+++ b/drivers/net/virtio/virtio_ring.h
@@ -108,14 +108,25 @@ set_desc_avail(struct vring *vr, struct vring_desc_packed *desc)
}
static inline int
-desc_is_used(struct vring_desc_packed *desc, struct vring *vr)
+_desc_is_used(struct vring_desc_packed *desc)
{
uint16_t used, avail;
used = !!(desc->flags & VRING_DESC_F_USED(1));
avail = !!(desc->flags & VRING_DESC_F_AVAIL(1));
- return used == avail && used == vr->used_wrap_counter;
+ return used == avail;
+
+}
+
+static inline int
+desc_is_used(struct vring_desc_packed *desc, struct vring *vr)
+{
+ uint16_t used;
+
+ used = !!(desc->flags & VRING_DESC_F_USED(1));
+
+ return _desc_is_used(desc) && used == vr->used_wrap_counter;
}
/* The standard layout for the ring is a continuous chunk of memory which
diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c
index eb891433e..4078fba8e 100644
--- a/drivers/net/virtio/virtio_rxtx.c
+++ b/drivers/net/virtio/virtio_rxtx.c
@@ -38,6 +38,7 @@
#define VIRTIO_DUMP_PACKET(m, len) do { } while (0)
#endif
+
int
virtio_dev_rx_queue_done(void *rxq, uint16_t offset)
{
@@ -88,6 +89,41 @@ 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)
+{
+ struct vring_desc_packed *dp;
+ struct vq_desc_extra *dxp = NULL, *dxp_tail = NULL;
+ uint16_t desc_idx_last = desc_idx;
+
+ dp = &vq->vq_ring.desc_packed[desc_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) {
+ desc_idx_last = dxp->next;
+ dp = &vq->vq_ring.desc_packed[dxp->next];
+ dxp = &vq->vq_descx[dxp->next];
+ }
+ }
+
+ /*
+ * 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)
+{
+ 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 (desc_is_used(&desc[used_idx], &vq->vq_ring) &&
+ vq->vq_free_cnt < size) {
+ used_idx = vq->vq_used_cons_idx;
+ id = desc[used_idx].index;
+ dxp = &vq->vq_descx[id];
+ if (++vq->vq_used_cons_idx >= size) {
+ vq->vq_used_cons_idx -= size;
+ vq->vq_ring.used_wrap_counter ^= 1;
+ }
+ vq_ring_free_chain_packed(vq, id);
+ 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 +519,128 @@ 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;
+ uint16_t head_size = vq->hw->vtnet_hdr_size;
+ struct virtio_net_hdr *hdr;
+ int wrap_counter = vq->vq_ring.avail_wrap_counter;
+
+ head_id = vq->vq_desc_head_idx;
+ idx = head_id;
+ 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];
+ head_dxp->cookie = (void *) cookie;
+
+ if (can_push) {
+ /* prepend cannot fail, checked by caller */
+ hdr = (struct virtio_net_hdr *)
+ rte_pktmbuf_prepend(cookie, head_size);
+ /* rte_pktmbuf_prepend() counts the hdr size to the pkt length,
+ * which is wrong. Below subtract restores correct pkt size.
+ */
+ cookie->pkt_len -= head_size;
+
+ /* if offload disabled, it is not zeroed below, do it now */
+ if (!vq->hw->has_tx_offload) {
+ ASSIGN_UNLESS_EQUAL(hdr->csum_start, 0);
+ ASSIGN_UNLESS_EQUAL(hdr->csum_offset, 0);
+ ASSIGN_UNLESS_EQUAL(hdr->flags, 0);
+ ASSIGN_UNLESS_EQUAL(hdr->gso_type, 0);
+ ASSIGN_UNLESS_EQUAL(hdr->gso_size, 0);
+ ASSIGN_UNLESS_EQUAL(hdr->hdr_len, 0);
+ }
+ } else if (use_indirect) {
+ /* setup tx ring slot to point to indirect
+ * descriptor list stored in reserved region.
+ *
+ * the first slot in indirect ring is already preset
+ * to point to the header in reserved region
+ */
+ start_dp[idx].addr = txvq->virtio_net_hdr_mem +
+ RTE_PTR_DIFF(&txr[idx].tx_indir_pq, txr);
+ start_dp[idx].len = (seg_num + 1) * sizeof(struct vring_desc_packed);
+ start_dp[idx].flags = VRING_DESC_F_INDIRECT;
+ hdr = (struct virtio_net_hdr *)&txr[idx].tx_hdr;
+
+ /* loop below will fill in rest of the indirect elements */
+ start_dp = txr[idx].tx_indir_pq;
+ idx = 1;
+ } else {
+ /* setup first tx ring slot to point to header
+ * stored in reserved region.
+ */
+ start_dp[idx].addr = txvq->virtio_net_hdr_mem +
+ RTE_PTR_DIFF(&txr[idx].tx_hdr, txr);
+ start_dp[idx].len = vq->hw->vtnet_hdr_size;
+ start_dp[idx].flags = VRING_DESC_F_NEXT;
+ start_dp[idx].flags |=
+ VRING_DESC_F_AVAIL(vq->vq_ring.avail_wrap_counter) |
+ VRING_DESC_F_USED(!vq->vq_ring.avail_wrap_counter);
+ hdr = (struct virtio_net_hdr *)&txr[idx].tx_hdr;
+ idx = dxp->next;
+ }
+
+ virtqueue_xmit_offload(hdr, cookie, vq->hw->has_tx_offload);
+
+ do {
+ if (idx >= vq->vq_nentries) {
+ idx = 0;
+ vq->vq_ring.avail_wrap_counter ^= 1;
+ }
+ start_dp[idx].addr = VIRTIO_MBUF_DATA_DMA_ADDR(cookie, vq);
+ start_dp[idx].len = cookie->data_len;
+ start_dp[idx].flags = cookie->next ? VRING_DESC_F_NEXT : 0;
+ start_dp[idx].flags |=
+ VRING_DESC_F_AVAIL(vq->vq_ring.avail_wrap_counter) |
+ VRING_DESC_F_USED(!vq->vq_ring.avail_wrap_counter);
+ if (use_indirect) {
+ if (++idx >= (seg_num + 1))
+ break;
+ } else {
+ dxp = &vq->vq_descx[idx];
+ idx = dxp->next;
+ }
+ } while ((cookie = cookie->next) != NULL);
+
+ if (use_indirect)
+ idx = vq->vq_ring.desc_packed[head_id].index;
+
+ vq->vq_free_cnt = (uint16_t)(vq->vq_free_cnt - needed);
+
+ rte_smp_wmb();
+ if (needed > 1)
+ head_dp->flags = VRING_DESC_F_NEXT |
+ VRING_DESC_F_AVAIL(wrap_counter) |
+ VRING_DESC_F_USED(!wrap_counter);
+ rte_smp_mb();
+
+ if (!in_order) {
+ if (vq->vq_desc_head_idx == VQ_RING_DESC_CHAIN_END)
+ vq->vq_desc_tail_idx = idx;
+ }
+ if (idx >= vq->vq_nentries) {
+ idx = 0;
+ vq->vq_ring.avail_wrap_counter ^= 1;
+ }
+ vq->vq_desc_head_idx = idx;
+ vq->vq_avail_idx = idx;
+
+}
+
+
static inline void
virtqueue_enqueue_xmit(struct virtnet_tx *txvq, struct rte_mbuf *cookie,
uint16_t needed, int use_indirect, int can_push,
@@ -1346,6 +1531,97 @@ virtio_recv_mergeable_pkts(void *rx_queue,
return nb_rx;
}
+uint16_t
+virtio_xmit_pkts_packed(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
+{
+ struct virtnet_tx *txvq = tx_queue;
+ struct virtqueue *vq = txvq->vq;
+ struct virtio_hw *hw = vq->hw;
+ uint16_t hdr_size = hw->vtnet_hdr_size;
+ uint16_t nb_tx = 0;
+ int error;
+
+ if (unlikely(hw->started == 0 && tx_pkts != hw->inject_pkts))
+ return nb_tx;
+
+ if (unlikely(nb_pkts < 1))
+ return nb_pkts;
+
+ PMD_TX_LOG(DEBUG, "%d packets to xmit", nb_pkts);
+
+ virtio_rmb();
+ if (likely(nb_pkts > vq->vq_nentries - vq->vq_free_thresh))
+ virtio_xmit_cleanup_packed(vq);
+
+ for (nb_tx = 0; nb_tx < nb_pkts; nb_tx++) {
+ struct rte_mbuf *txm = tx_pkts[nb_tx];
+ int can_push = 0, use_indirect = 0, slots, need;
+
+ /* Do VLAN tag insertion */
+ if (unlikely(txm->ol_flags & PKT_TX_VLAN_PKT)) {
+ error = rte_vlan_insert(&txm);
+ if (unlikely(error)) {
+ rte_pktmbuf_free(txm);
+ continue;
+ }
+ }
+
+ /* optimize ring usage */
+ if ((vtpci_with_feature(hw, VIRTIO_F_ANY_LAYOUT) ||
+ vtpci_with_feature(hw, VIRTIO_F_VERSION_1)) &&
+ rte_mbuf_refcnt_read(txm) == 1 &&
+ RTE_MBUF_DIRECT(txm) &&
+ txm->nb_segs == 1 &&
+ rte_pktmbuf_headroom(txm) >= hdr_size &&
+ rte_is_aligned(rte_pktmbuf_mtod(txm, char *),
+ __alignof__(struct virtio_net_hdr_mrg_rxbuf)))
+ can_push = 1;
+ else if (vtpci_with_feature(hw, VIRTIO_RING_F_INDIRECT_DESC) &&
+ txm->nb_segs < VIRTIO_MAX_TX_INDIRECT)
+ use_indirect = 1;
+
+ /* How many main ring entries are needed to this Tx?
+ * any_layout => number of segments
+ * indirect => 1
+ * default => number of segments + 1
+ */
+ slots = use_indirect ? 1 : (txm->nb_segs + !can_push);
+ need = slots - vq->vq_free_cnt;
+
+ /* Positive value indicates it need free vring descriptors */
+ if (unlikely(need > 0)) {
+ virtio_rmb();
+ need = RTE_MIN(need, (int)nb_pkts);
+
+ virtio_xmit_cleanup_packed(vq);
+ need = slots - vq->vq_free_cnt;
+ if (unlikely(need > 0)) {
+ PMD_TX_LOG(ERR,
+ "No free tx descriptors to transmit");
+ break;
+ }
+ }
+
+ /* Enqueue Packet buffers */
+ virtqueue_enqueue_xmit_packed(txvq, txm, slots, use_indirect,
+ can_push, 0);
+
+ txvq->stats.bytes += txm->pkt_len;
+ virtio_update_packet_stats(&txvq->stats, txm);
+ }
+
+ txvq->stats.packets += nb_tx;
+
+ if (likely(nb_tx)) {
+ if (unlikely(virtqueue_kick_prepare_packed(vq))) {
+ virtqueue_notify(vq);
+ PMD_TX_LOG(DEBUG, "Notified backend after xmit");
+ }
+ }
+
+ return nb_tx;
+}
+
uint16_t
virtio_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
{
diff --git a/drivers/net/virtio/virtqueue.h b/drivers/net/virtio/virtqueue.h
index 549962c28..58f600648 100644
--- a/drivers/net/virtio/virtqueue.h
+++ b/drivers/net/virtio/virtqueue.h
@@ -242,8 +242,12 @@ struct virtio_net_hdr_mrg_rxbuf {
#define VIRTIO_MAX_TX_INDIRECT 8
struct virtio_tx_region {
struct virtio_net_hdr_mrg_rxbuf tx_hdr;
- struct vring_desc tx_indir[VIRTIO_MAX_TX_INDIRECT]
- __attribute__((__aligned__(16)));
+ union {
+ struct vring_desc tx_indir[VIRTIO_MAX_TX_INDIRECT]
+ __attribute__((__aligned__(16)));
+ struct vring_desc_packed tx_indir_pq[VIRTIO_MAX_TX_INDIRECT]
+ __attribute__((__aligned__(16)));
+ };
};
static inline uint16_t
@@ -328,6 +332,7 @@ virtio_get_queue_type(struct virtio_hw *hw, uint16_t vtpci_queue_idx)
#define VIRTQUEUE_NUSED(vq) ((uint16_t)((vq)->vq_ring.used->idx - (vq)->vq_used_cons_idx))
void vq_ring_free_chain(struct virtqueue *vq, uint16_t desc_idx);
+void vq_ring_free_chain_packed(struct virtqueue *vq, uint16_t desc_idx);
void vq_ring_free_inorder(struct virtqueue *vq, uint16_t desc_idx,
uint16_t num);
@@ -361,6 +366,15 @@ virtqueue_kick_prepare(struct virtqueue *vq)
return !(vq->vq_ring.used->flags & VRING_USED_F_NO_NOTIFY);
}
+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;
+ return (flags != RING_EVENT_FLAGS_DISABLE);
+}
+
static inline void
virtqueue_notify(struct virtqueue *vq)
{
--
2.17.1
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