[dpdk-dev,v7,3/7] vhost: simplify mergeable Rx vring reservation
Commit Message
Let it return "num_buffers" we reserved, so that we could re-use it
with copy_mbuf_to_desc_mergeable() directly, instead of calculating
it again there.
Meanwhile, the return type of copy_mbuf_to_desc_mergeable is changed
to "int". -1 will be return on error.
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Signed-off-by: Zhihong Wang <zhihong.wang@intel.com>
---
lib/librte_vhost/virtio_net.c | 41 +++++++++++++++++++++--------------------
1 file changed, 21 insertions(+), 20 deletions(-)
Comments
2016-10-14 17:34, Yuanhan Liu:
> -static inline uint32_t __attribute__((always_inline))
> +static inline int __attribute__((always_inline))
> copy_mbuf_to_desc_mergeable(struct virtio_net *dev, struct vhost_virtqueue *vq,
> - uint16_t end_idx, struct rte_mbuf *m,
> - struct buf_vector *buf_vec)
> + struct rte_mbuf *m, struct buf_vector *buf_vec,
> + uint16_t num_buffers)
> {
> struct virtio_net_hdr_mrg_rxbuf virtio_hdr = {{0, 0, 0, 0, 0, 0}, 0};
> uint32_t vec_idx = 0;
> - uint16_t start_idx = vq->last_used_idx;
> - uint16_t cur_idx = start_idx;
> + uint16_t cur_idx = vq->last_used_idx;
> uint64_t desc_addr;
> uint32_t desc_chain_head;
> uint32_t desc_chain_len;
> @@ -394,21 +393,21 @@ copy_mbuf_to_desc_mergeable(struct virtio_net *dev, struct vhost_virtqueue *vq,
> struct rte_mbuf *hdr_mbuf;
>
> if (unlikely(m == NULL))
> - return 0;
> + return -1;
>
> LOG_DEBUG(VHOST_DATA, "(%d) current index %d | end index %d\n",
> dev->vid, cur_idx, end_idx);
There is a build error:
lib/librte_vhost/virtio_net.c:399:22: error: ‘end_idx’ undeclared
It is probably trivial and could be fixed directly in the already applied
commit in next-virtio.
On Wed, Oct 26, 2016 at 12:08:49AM +0200, Thomas Monjalon wrote:
> 2016-10-14 17:34, Yuanhan Liu:
> > -static inline uint32_t __attribute__((always_inline))
> > +static inline int __attribute__((always_inline))
> > copy_mbuf_to_desc_mergeable(struct virtio_net *dev, struct vhost_virtqueue *vq,
> > - uint16_t end_idx, struct rte_mbuf *m,
> > - struct buf_vector *buf_vec)
> > + struct rte_mbuf *m, struct buf_vector *buf_vec,
> > + uint16_t num_buffers)
> > {
> > struct virtio_net_hdr_mrg_rxbuf virtio_hdr = {{0, 0, 0, 0, 0, 0}, 0};
> > uint32_t vec_idx = 0;
> > - uint16_t start_idx = vq->last_used_idx;
> > - uint16_t cur_idx = start_idx;
> > + uint16_t cur_idx = vq->last_used_idx;
> > uint64_t desc_addr;
> > uint32_t desc_chain_head;
> > uint32_t desc_chain_len;
> > @@ -394,21 +393,21 @@ copy_mbuf_to_desc_mergeable(struct virtio_net *dev, struct vhost_virtqueue *vq,
> > struct rte_mbuf *hdr_mbuf;
> >
> > if (unlikely(m == NULL))
> > - return 0;
> > + return -1;
> >
> > LOG_DEBUG(VHOST_DATA, "(%d) current index %d | end index %d\n",
> > dev->vid, cur_idx, end_idx);
>
> There is a build error:
> lib/librte_vhost/virtio_net.c:399:22: error: ‘end_idx’ undeclared
Oops... you know, my robot is broken since the holiday :(
I just had a quick fix. Hopefully, it will start working again...
> It is probably trivial and could be fixed directly in the already applied
> commit in next-virtio.
Yes, and FYI, here is the overall diffs I made to fix this bug.
--yliu
---
diff --git a/lib/librte_vhost/virtio_net.c
b/lib/librte_vhost/virtio_net.c
index b784dba..eed0b1c 100644
--- a/lib/librte_vhost/virtio_net.c
+++ b/lib/librte_vhost/virtio_net.c
@@ -443,9 +443,6 @@ copy_mbuf_to_desc_mergeable(struct virtio_net *dev,
struct rte_mbuf *m,
if (unlikely(m == NULL))
return -1;
- LOG_DEBUG(VHOST_DATA, "(%d) current index %d | end index %d\n",
- dev->vid, cur_idx, end_idx);
-
desc_addr = gpa_to_vva(dev, buf_vec[vec_idx].buf_addr);
if (buf_vec[vec_idx].buf_len < dev->vhost_hlen || !desc_addr)
return -1;
@@ -555,6 +552,10 @@ virtio_dev_merge_rx(struct virtio_net *dev,
uint16_t queue_id,
break;
}
+ LOG_DEBUG(VHOST_DATA, "(%d) current index %d | end index %d\n",
+ dev->vid, vq->last_avail_idx,
+ vq->last_avail_idx + num_buffers);
+
if (copy_mbuf_to_desc_mergeable(dev, pkts[pkt_idx],
buf_vec, num_buffers) < 0) {
vq->shadow_used_idx -= num_buffers;
@@ -336,7 +336,7 @@ fill_vec_buf(struct vhost_virtqueue *vq, uint32_t avail_idx,
*/
static inline int
reserve_avail_buf_mergeable(struct vhost_virtqueue *vq, uint32_t size,
- uint16_t *end, struct buf_vector *buf_vec)
+ struct buf_vector *buf_vec, uint16_t *num_buffers)
{
uint16_t cur_idx;
uint16_t avail_idx;
@@ -370,19 +370,18 @@ reserve_avail_buf_mergeable(struct vhost_virtqueue *vq, uint32_t size,
return -1;
}
- *end = cur_idx;
+ *num_buffers = cur_idx - vq->last_used_idx;
return 0;
}
-static inline uint32_t __attribute__((always_inline))
+static inline int __attribute__((always_inline))
copy_mbuf_to_desc_mergeable(struct virtio_net *dev, struct vhost_virtqueue *vq,
- uint16_t end_idx, struct rte_mbuf *m,
- struct buf_vector *buf_vec)
+ struct rte_mbuf *m, struct buf_vector *buf_vec,
+ uint16_t num_buffers)
{
struct virtio_net_hdr_mrg_rxbuf virtio_hdr = {{0, 0, 0, 0, 0, 0}, 0};
uint32_t vec_idx = 0;
- uint16_t start_idx = vq->last_used_idx;
- uint16_t cur_idx = start_idx;
+ uint16_t cur_idx = vq->last_used_idx;
uint64_t desc_addr;
uint32_t desc_chain_head;
uint32_t desc_chain_len;
@@ -394,21 +393,21 @@ copy_mbuf_to_desc_mergeable(struct virtio_net *dev, struct vhost_virtqueue *vq,
struct rte_mbuf *hdr_mbuf;
if (unlikely(m == NULL))
- return 0;
+ return -1;
LOG_DEBUG(VHOST_DATA, "(%d) current index %d | end index %d\n",
dev->vid, cur_idx, end_idx);
desc_addr = gpa_to_vva(dev, buf_vec[vec_idx].buf_addr);
if (buf_vec[vec_idx].buf_len < dev->vhost_hlen || !desc_addr)
- return 0;
+ return -1;
hdr_mbuf = m;
hdr_addr = desc_addr;
hdr_phys_addr = buf_vec[vec_idx].buf_addr;
rte_prefetch0((void *)(uintptr_t)hdr_addr);
- virtio_hdr.num_buffers = end_idx - start_idx;
+ virtio_hdr.num_buffers = num_buffers;
LOG_DEBUG(VHOST_DATA, "(%d) RX: num merge buffers %d\n",
dev->vid, virtio_hdr.num_buffers);
@@ -440,7 +439,7 @@ copy_mbuf_to_desc_mergeable(struct virtio_net *dev, struct vhost_virtqueue *vq,
desc_addr = gpa_to_vva(dev, buf_vec[vec_idx].buf_addr);
if (unlikely(!desc_addr))
- return 0;
+ return -1;
/* Prefetch buffer address. */
rte_prefetch0((void *)(uintptr_t)desc_addr);
@@ -489,7 +488,7 @@ copy_mbuf_to_desc_mergeable(struct virtio_net *dev, struct vhost_virtqueue *vq,
offsetof(struct vring_used, ring[used_idx]),
sizeof(vq->used->ring[used_idx]));
- return end_idx - start_idx;
+ return 0;
}
static inline uint32_t __attribute__((always_inline))
@@ -497,8 +496,8 @@ virtio_dev_merge_rx(struct virtio_net *dev, uint16_t queue_id,
struct rte_mbuf **pkts, uint32_t count)
{
struct vhost_virtqueue *vq;
- uint32_t pkt_idx = 0, nr_used = 0;
- uint16_t end;
+ uint32_t pkt_idx = 0;
+ uint16_t num_buffers;
struct buf_vector buf_vec[BUF_VECTOR_MAX];
LOG_DEBUG(VHOST_DATA, "(%d) %s\n", dev->vid, __func__);
@@ -519,22 +518,24 @@ virtio_dev_merge_rx(struct virtio_net *dev, uint16_t queue_id,
for (pkt_idx = 0; pkt_idx < count; pkt_idx++) {
uint32_t pkt_len = pkts[pkt_idx]->pkt_len + dev->vhost_hlen;
- if (unlikely(reserve_avail_buf_mergeable(vq, pkt_len,
- &end, buf_vec) < 0)) {
+ if (unlikely(reserve_avail_buf_mergeable(vq, pkt_len, buf_vec,
+ &num_buffers) < 0)) {
LOG_DEBUG(VHOST_DATA,
"(%d) failed to get enough desc from vring\n",
dev->vid);
break;
}
- nr_used = copy_mbuf_to_desc_mergeable(dev, vq, end,
- pkts[pkt_idx], buf_vec);
+ if (copy_mbuf_to_desc_mergeable(dev, vq, pkts[pkt_idx],
+ buf_vec, num_buffers) < 0)
+ break;
+
rte_smp_wmb();
- *(volatile uint16_t *)&vq->used->idx += nr_used;
+ *(volatile uint16_t *)&vq->used->idx += num_buffers;
vhost_log_used_vring(dev, vq, offsetof(struct vring_used, idx),
sizeof(vq->used->idx));
- vq->last_used_idx += nr_used;
+ vq->last_used_idx += num_buffers;
}
if (likely(pkt_idx)) {