This patch fixes a Windows VM compatibility issue in DPDK 16.07 vhost code,
which causes the guest to hang once any packets are enqueued when mrg_rxbuf
is turned on.
How to test?
1. Start testpmd in the host with a vhost port.
2. Start a Windows VM image with qemu and connect to the vhost port.
3. Start io forwarding with tx_first in host testpmd.
For 16.07 code, the Windows VM will hang once any packets are enqueued.
Cc: <stable at dpdk.org>
Signed-off-by: Zhihong Wang <zhihong.wang at intel.com>
---
lib/librte_vhost/vhost_rxtx.c | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)
diff --git a/lib/librte_vhost/vhost_rxtx.c b/lib/librte_vhost/vhost_rxtx.c
index 08a73fd..5806f99 100644
--- a/lib/librte_vhost/vhost_rxtx.c
+++ b/lib/librte_vhost/vhost_rxtx.c
@@ -384,6 +384,8 @@ copy_mbuf_to_desc_mergeable(struct virtio_net *dev, struct
vhost_virtqueue *vq,
uint16_t start_idx = vq->last_used_idx;
uint16_t cur_idx = start_idx;
uint64_t desc_addr;
+ uint32_t desc_chain_head;
+ uint32_t desc_chain_len;
uint32_t mbuf_offset, mbuf_avail;
uint32_t desc_offset, desc_avail;
uint32_t cpy_len;
@@ -412,6 +414,8 @@ copy_mbuf_to_desc_mergeable(struct virtio_net *dev, struct
vhost_virtqueue *vq,
desc_avail = buf_vec[vec_idx].buf_len - dev->vhost_hlen;
desc_offset = dev->vhost_hlen;
+ desc_chain_head = buf_vec[vec_idx].desc_idx;
+ desc_chain_len = desc_offset;
mbuf_avail = rte_pktmbuf_data_len(m);
mbuf_offset = 0;
@@ -419,19 +423,21 @@ copy_mbuf_to_desc_mergeable(struct virtio_net *dev,
struct vhost_virtqueue *vq,
/* done with current desc buf, get the next one */
if (desc_avail == 0) {
desc_idx = buf_vec[vec_idx].desc_idx;
+ vec_idx++;
if (!(vq->desc[desc_idx].flags & VRING_DESC_F_NEXT)) {
/* Update used ring with desc information */
used_idx = cur_idx++ & (vq->size - 1);
- vq->used->ring[used_idx].id = desc_idx;
- vq->used->ring[used_idx].len = desc_offset;
+ vq->used->ring[used_idx].id = desc_chain_head;
+ vq->used->ring[used_idx].len = desc_chain_len;
vhost_log_used_vring(dev, vq,
offsetof(struct vring_used,
ring[used_idx]),
sizeof(vq->used->ring[used_idx]));
+ desc_chain_head = buf_vec[vec_idx].desc_idx;
+ desc_chain_len = 0;
}
- vec_idx++;
desc_addr = gpa_to_vva(dev, buf_vec[vec_idx].buf_addr);
if (unlikely(!desc_addr))
return 0;
@@ -463,11 +469,12 @@ copy_mbuf_to_desc_mergeable(struct virtio_net *dev,
struct vhost_virtqueue *vq,
mbuf_offset += cpy_len;
desc_avail -= cpy_len;
desc_offset += cpy_len;
+ desc_chain_len += cpy_len;
}
used_idx = cur_idx & (vq->size - 1);
- vq->used->ring[used_idx].id = buf_vec[vec_idx].desc_idx;
- vq->used->ring[used_idx].len = desc_offset;
+ vq->used->ring[used_idx].id = desc_chain_head;
+ vq->used->ring[used_idx].len = desc_chain_len;
vhost_log_used_vring(dev, vq,
offsetof(struct vring_used, ring[used_idx]),
sizeof(vq->used->ring[used_idx]));
--
2.7.4
