[dpdk-dev] [PATCH] virtio: fix used ring address calculation

[Xie, Huawei]

On 9/21/2015 11:39 AM, Xie, Huawei wrote:
vring_size calculation should consider both used_event_idx at the tail
of avail ring and avail_event_idx at the tail of used ring.
Will merge those two fixes and send a new patch.
> used event idx is put at the end of available ring. It isn't taken into account
> when we calculate the address of used ring. Fortunately, it doesn't introduce
> the bug with fixed queue number 256 and 4KB alignment.
>
> Signed-off-by: hxie5 <huawei.xie at intel.com>
> ---
>  drivers/net/virtio/virtio_ring.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/virtio/virtio_ring.h b/drivers/net/virtio/virtio_ring.h
> index a16c499..92e430d 100644
> --- a/drivers/net/virtio/virtio_ring.h
> +++ b/drivers/net/virtio/virtio_ring.h
> @@ -145,7 +145,7 @@ vring_init(struct vring *vr, unsigned int num, uint8_t *p,
>  	vr->avail = (struct vring_avail *) (p +
>  		num * sizeof(struct vring_desc));
>  	vr->used = (void *)
> -		RTE_ALIGN_CEIL((uintptr_t)(&vr->avail->ring[num]), align);
> +		RTE_ALIGN_CEIL((uintptr_t)(&vr->avail->ring[num + 1]), align);
>  }
>  
>  /*