[dpdk-dev] [PATCH v4 11/20] net/virtio: add support for event suppression
Jens Freimann
jfreimann at redhat.com
Thu Apr 19 09:07:42 CEST 2018
Signed-off-by: Jens Freimann <jfreimann at redhat.com>
---
drivers/net/virtio/virtio_ethdev.c | 2 +-
drivers/net/virtio/virtio_rxtx.c | 15 +++++++-
drivers/net/virtio/virtqueue.h | 77 ++++++++++++++++++++++++++++++++++++--
3 files changed, 89 insertions(+), 5 deletions(-)
diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
index f9af3fcdb..30c04aa19 100644
--- a/drivers/net/virtio/virtio_ethdev.c
+++ b/drivers/net/virtio/virtio_ethdev.c
@@ -802,7 +802,7 @@ virtio_dev_rx_queue_intr_enable(struct rte_eth_dev *dev, uint16_t queue_id)
struct virtnet_rx *rxvq = dev->data->rx_queues[queue_id];
struct virtqueue *vq = rxvq->vq;
- virtqueue_enable_intr(vq);
+ virtqueue_enable_intr(vq, 0, 0);
return 0;
}
diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c
index 42b1d5997..a6b24ea64 100644
--- a/drivers/net/virtio/virtio_rxtx.c
+++ b/drivers/net/virtio/virtio_rxtx.c
@@ -128,6 +128,10 @@ virtio_xmit_pkts_packed(void *tx_queue, struct rte_mbuf **tx_pkts,
rte_smp_wmb();
_set_desc_avail(&desc[head_idx], wrap_counter);
vq->vq_descx[head_idx].ndescs = descs_used;
+ if (unlikely(virtqueue_kick_prepare_packed(vq))) {
+ virtqueue_notify(vq);
+ PMD_RX_LOG(DEBUG, "Notified");
+ }
}
txvq->stats.packets += i;
@@ -1003,6 +1007,10 @@ virtio_recv_pkts_packed(void *rx_queue, struct rte_mbuf **rx_pkts,
}
rxvq->stats.packets += nb_rx;
+ if (nb_rx > 0 && unlikely(virtqueue_kick_prepare_packed(vq))) {
+ virtqueue_notify(vq);
+ PMD_RX_LOG(DEBUG, "Notified");
+ }
vq->vq_used_cons_idx = used_idx;
@@ -1280,8 +1288,13 @@ virtio_recv_mergeable_pkts(void *rx_queue,
rxvq->stats.packets += nb_rx;
- if (vtpci_packed_queue(vq->hw))
+ if (vtpci_packed_queue(vq->hw)) {
+ if (unlikely(virtqueue_kick_prepare(vq))) {
+ virtqueue_notify(vq);
+ PMD_RX_LOG(DEBUG, "Notified");
+ }
return nb_rx;
+ }
/* Allocate new mbuf for the used descriptor */
error = ENOSPC;
diff --git a/drivers/net/virtio/virtqueue.h b/drivers/net/virtio/virtqueue.h
index 0df845e0b..96152ac76 100644
--- a/drivers/net/virtio/virtqueue.h
+++ b/drivers/net/virtio/virtqueue.h
@@ -176,6 +176,8 @@ struct virtqueue {
uint16_t vq_free_cnt; /**< num of desc available */
uint16_t vq_avail_idx; /**< sync until needed */
uint16_t vq_free_thresh; /**< free threshold */
+ uint16_t vq_signalled_avail;
+ int vq_signalled_avail_valid;
void *vq_ring_virt_mem; /**< linear address of vring*/
unsigned int vq_ring_size;
@@ -292,16 +294,37 @@ vring_desc_init(struct vring_desc *dp, uint16_t n)
static inline void
virtqueue_disable_intr(struct virtqueue *vq)
{
- vq->vq_ring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
+ if (vtpci_packed_queue(vq->hw) && vtpci_with_feature(vq->hw,
+ VIRTIO_RING_F_EVENT_IDX))
+ vq->vq_ring.device_event->desc_event_flags =
+ RING_EVENT_FLAGS_DISABLE;
+ else
+ vq->vq_ring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
}
/**
* Tell the backend to interrupt us.
*/
static inline void
-virtqueue_enable_intr(struct virtqueue *vq)
+virtqueue_enable_intr(struct virtqueue *vq, uint16_t off, uint16_t wrap_counter)
{
- vq->vq_ring.avail->flags &= (~VRING_AVAIL_F_NO_INTERRUPT);
+ uint16_t *flags = &vq->vq_ring.device_event->desc_event_flags;
+ uint16_t *event_off_wrap =
+ &vq->vq_ring.device_event->desc_event_off_wrap;
+ if (vtpci_packed_queue(vq->hw)) {
+ *flags = 0;
+ *event_off_wrap = 0;
+ if (*event_off_wrap & RING_EVENT_FLAGS_DESC) {
+ *event_off_wrap = off | 0x7FFF;
+ *event_off_wrap |= wrap_counter << 15;
+ *flags |= RING_EVENT_FLAGS_DESC;
+ } else {
+ *event_off_wrap = 0;
+ }
+ *flags |= RING_EVENT_FLAGS_ENABLE;
+ } else {
+ vq->vq_ring.avail->flags &= (~VRING_AVAIL_F_NO_INTERRUPT);
+ }
}
/**
@@ -361,12 +384,60 @@ vq_update_avail_ring(struct virtqueue *vq, uint16_t desc_idx)
vq->vq_avail_idx++;
}
+static int vhost_idx_diff(struct virtqueue *vq, uint16_t old, uint16_t new)
+{
+ if (new > old)
+ return new - old;
+ return (new + vq->vq_nentries - old);
+}
+
+static int vring_packed_need_event(struct virtqueue *vq,
+ uint16_t event_off, uint16_t new,
+ uint16_t old)
+{
+ return (uint16_t)(vhost_idx_diff(vq, new, event_off) - 1) <
+ (uint16_t)vhost_idx_diff(vq, new, old);
+}
+
+
static inline int
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 notify_offset, flags, wrap;
+ uint16_t old, new;
+ int v;
+
+ if (vtpci_packed_queue(vq->hw)) {
+ flags = vq->vq_ring.device_event->desc_event_flags;
+ if (!(flags & RING_EVENT_FLAGS_DESC))
+ return flags & RING_EVENT_FLAGS_ENABLE;
+ virtio_rmb();
+ notify_offset = vq->vq_ring.device_event->desc_event_off_wrap;
+ wrap = notify_offset & 0x1;
+ notify_offset >>= 1;
+
+ old = vq->vq_signalled_avail;
+ v = vq->vq_signalled_avail_valid;
+ new = vq->vq_avail_idx;
+ vq->vq_signalled_avail = vq->vq_avail_idx;
+ vq->vq_signalled_avail_valid = 1;
+
+ if (unlikely(!v))
+ return 0;
+
+ return (vring_packed_need_event(vq, new, old, notify_offset) &&
+ wrap == vq->vq_ring.avail_wrap_counter);
+ } else {
+ return !(vq->vq_ring.used->flags & VRING_USED_F_NO_NOTIFY);
+ }
+}
+
static inline void
virtqueue_notify(struct virtqueue *vq)
{
--
2.14.3
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