[dpdk-dev] [PATCH 3/4] vhost: log vring changes
Yuanhan Liu
yuanhan.liu at linux.intel.com
Wed Dec 2 04:43:12 CET 2015
Invoking vhost_log_write() to mark corresponding page as dirty while
updating used vring.
Signed-off-by: Yuanhan Liu <yuanhan.liu at linux.intel.com>
---
lib/librte_vhost/vhost_rxtx.c | 74 +++++++++++++++++++++++++++++--------------
1 file changed, 50 insertions(+), 24 deletions(-)
diff --git a/lib/librte_vhost/vhost_rxtx.c b/lib/librte_vhost/vhost_rxtx.c
index 9322ce6..d4805d8 100644
--- a/lib/librte_vhost/vhost_rxtx.c
+++ b/lib/librte_vhost/vhost_rxtx.c
@@ -129,6 +129,7 @@ virtio_dev_rx(struct virtio_net *dev, uint16_t queue_id,
uint32_t offset = 0, vb_offset = 0;
uint32_t pkt_len, len_to_cpy, data_len, total_copied = 0;
uint8_t hdr = 0, uncompleted_pkt = 0;
+ uint16_t idx;
/* Get descriptor from available ring */
desc = &vq->desc[head[packet_success]];
@@ -200,16 +201,22 @@ virtio_dev_rx(struct virtio_net *dev, uint16_t queue_id,
}
/* Update used ring with desc information */
- vq->used->ring[res_cur_idx & (vq->size - 1)].id =
- head[packet_success];
+ idx = res_cur_idx & (vq->size - 1);
+ vq->used->ring[idx].id = head[packet_success];
/* Drop the packet if it is uncompleted */
if (unlikely(uncompleted_pkt == 1))
- vq->used->ring[res_cur_idx & (vq->size - 1)].len =
- vq->vhost_hlen;
+ vq->used->ring[idx].len = vq->vhost_hlen;
else
- vq->used->ring[res_cur_idx & (vq->size - 1)].len =
- pkt_len + vq->vhost_hlen;
+ vq->used->ring[idx].len = pkt_len + vq->vhost_hlen;
+
+ /*
+ * to defer the update to when updating used->idx,
+ * and batch them?
+ */
+ vhost_log_write(dev, vq,
+ offsetof(struct vring_used, ring[idx]),
+ sizeof(vq->used->ring[idx]));
res_cur_idx++;
packet_success++;
@@ -236,6 +243,9 @@ virtio_dev_rx(struct virtio_net *dev, uint16_t queue_id,
*(volatile uint16_t *)&vq->used->idx += count;
vq->last_used_idx = res_end_idx;
+ vhost_log_write(dev, vq,
+ offsetof(struct vring_used, idx),
+ sizeof(vq->used->idx));
/* flush used->idx update before we read avail->flags. */
rte_mb();
@@ -265,6 +275,7 @@ copy_from_mbuf_to_vring(struct virtio_net *dev, uint32_t queue_id,
uint32_t seg_avail;
uint32_t vb_avail;
uint32_t cpy_len, entry_len;
+ uint16_t idx;
if (pkt == NULL)
return 0;
@@ -302,16 +313,18 @@ copy_from_mbuf_to_vring(struct virtio_net *dev, uint32_t queue_id,
entry_len = vq->vhost_hlen;
if (vb_avail == 0) {
- uint32_t desc_idx =
- vq->buf_vec[vec_idx].desc_idx;
+ uint32_t desc_idx = vq->buf_vec[vec_idx].desc_idx;
+
+ if ((vq->desc[desc_idx].flags & VRING_DESC_F_NEXT) == 0) {
+ idx = cur_idx & (vq->size - 1);
- if ((vq->desc[desc_idx].flags
- & VRING_DESC_F_NEXT) == 0) {
/* Update used ring with desc information */
- vq->used->ring[cur_idx & (vq->size - 1)].id
- = vq->buf_vec[vec_idx].desc_idx;
- vq->used->ring[cur_idx & (vq->size - 1)].len
- = entry_len;
+ vq->used->ring[idx].id = vq->buf_vec[vec_idx].desc_idx;
+ vq->used->ring[idx].len = entry_len;
+
+ vhost_log_write(dev, vq,
+ offsetof(struct vring_used, ring[idx]),
+ sizeof(vq->used->ring[idx]));
entry_len = 0;
cur_idx++;
@@ -354,10 +367,13 @@ copy_from_mbuf_to_vring(struct virtio_net *dev, uint32_t queue_id,
if ((vq->desc[vq->buf_vec[vec_idx].desc_idx].flags &
VRING_DESC_F_NEXT) == 0) {
/* Update used ring with desc information */
- vq->used->ring[cur_idx & (vq->size - 1)].id
+ idx = cur_idx & (vq->size - 1);
+ vq->used->ring[idx].id
= vq->buf_vec[vec_idx].desc_idx;
- vq->used->ring[cur_idx & (vq->size - 1)].len
- = entry_len;
+ vq->used->ring[idx].len = entry_len;
+ vhost_log_write(dev, vq,
+ offsetof(struct vring_used, ring[idx]),
+ sizeof(vq->used->ring[idx]));
entry_len = 0;
cur_idx++;
entry_success++;
@@ -390,16 +406,18 @@ copy_from_mbuf_to_vring(struct virtio_net *dev, uint32_t queue_id,
if ((vq->desc[desc_idx].flags &
VRING_DESC_F_NEXT) == 0) {
- uint16_t wrapped_idx =
- cur_idx & (vq->size - 1);
+ idx = cur_idx & (vq->size - 1);
/*
* Update used ring with the
* descriptor information
*/
- vq->used->ring[wrapped_idx].id
+ vq->used->ring[idx].id
= desc_idx;
- vq->used->ring[wrapped_idx].len
+ vq->used->ring[idx].len
= entry_len;
+ vhost_log_write(dev, vq,
+ offsetof(struct vring_used, ring[idx]),
+ sizeof(vq->used->ring[idx]));
entry_success++;
entry_len = 0;
cur_idx++;
@@ -422,10 +440,13 @@ copy_from_mbuf_to_vring(struct virtio_net *dev, uint32_t queue_id,
* This whole packet completes.
*/
/* Update used ring with desc information */
- vq->used->ring[cur_idx & (vq->size - 1)].id
+ idx = cur_idx & (vq->size - 1);
+ vq->used->ring[idx].id
= vq->buf_vec[vec_idx].desc_idx;
- vq->used->ring[cur_idx & (vq->size - 1)].len
- = entry_len;
+ vq->used->ring[idx].len = entry_len;
+ vhost_log_write(dev, vq,
+ offsetof(struct vring_used, ring[idx]),
+ sizeof(vq->used->ring[idx]));
entry_success++;
break;
}
@@ -658,6 +679,9 @@ rte_vhost_dequeue_burst(struct virtio_net *dev, uint16_t queue_id,
/* Update used index buffer information. */
vq->used->ring[used_idx].id = head[entry_success];
vq->used->ring[used_idx].len = 0;
+ vhost_log_write(dev, vq,
+ offsetof(struct vring_used, ring[used_idx]),
+ sizeof(vq->used->ring[used_idx]));
/* Allocate an mbuf and populate the structure. */
m = rte_pktmbuf_alloc(mbuf_pool);
@@ -778,6 +802,8 @@ rte_vhost_dequeue_burst(struct virtio_net *dev, uint16_t queue_id,
rte_compiler_barrier();
vq->used->idx += entry_success;
+ vhost_log_write(dev, vq, offsetof(struct vring_used, idx),
+ sizeof(vq->used->idx));
/* Kick guest if required. */
if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT))
eventfd_write(vq->callfd, (eventfd_t)1);
--
1.9.0
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