On Sun, Jun 12, 2016 at 10:05:45AM +0000, Jianfeng Tan wrote:
> This patches fixes problem of reusing index of outmost loop in nested
> loops. This bug will lead to failure when starting a multi queue
> virtio device: rx queues (except from the first one) cannot be started,
> expecially their vq_ring cannot be initialized, so that when invoking
> rx func on these queues, segment fault happens.
>
> Fixes: a900472aedef ("virtio: split virtio Rx/Tx queue")
Good catch!
> Signed-off-by: Jianfeng Tan <jianfeng.tan at intel.com>
> ---
> drivers/net/virtio/virtio_rxtx.c | 36 ++++++++++++++++++++----------------
> 1 file changed, 20 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/net/virtio/virtio_rxtx.c
> b/drivers/net/virtio/virtio_rxtx.c
> index 2e7205b..b96d0cb 100644
> --- a/drivers/net/virtio/virtio_rxtx.c
> +++ b/drivers/net/virtio/virtio_rxtx.c
> @@ -331,7 +331,7 @@ virtio_dev_rxtx_start(struct rte_eth_dev *dev)
> * - Allocate blank mbufs for the each rx descriptor
> *
> */
> - int i;
> + int i, j;
However, I don't quite like using "i, j, k" stuff. So, how about
renaming "j" to "ring_idx"?
> PMD_INIT_FUNC_TRACE();
>
> @@ -352,15 +352,18 @@ virtio_dev_rxtx_start(struct rte_eth_dev *dev)
> error = ENOSPC;
>
> #ifdef RTE_MACHINE_CPUFLAG_SSSE3
> - if (use_simple_rxtx)
> - for (i = 0; i < vq->vq_nentries; i++) {
> - vq->vq_ring.avail->ring[i] = i;
> - vq->vq_ring.desc[i].flags = VRING_DESC_F_WRITE;
> + if (use_simple_rxtx) {
> + uint16_t k;
We could reuse "ring_idx" here; no need to define yet another iterate var
for that.
--yliu
