[dpdk-dev] [PATCH] vhost: disable indirect descriptors feature

[Maxime Coquelin]

Hi Yuanhan,

On 10/17/2016 05:10 PM, Maxime Coquelin wrote:
> Commit 2304dd73d287 ("vhost: support indirect Tx descriptors")
> adds support for indirect descriptors for Tx, but not for Rx.
>
> The problem is that it does not work with windows guests, which
> uses indirect descriptors for the Rx, and also with Linux guests
> when using kernel driver with mergeable buffers feature disabled.
>
> While indirect descriptors support is also added to the Rx path,
> let's disable the feature.
>
> Reported-by: Zhihong Wang <zhihong.wang at intel.com>
> Reported-by: Ciara Loftus <ciara.loftus at intel.com>
> Cc: Yuanhan Liu <yuanhan.liu at linux.intel.com>
> Signed-off-by: Maxime Coquelin <maxime.coquelin at redhat.com>
> ---
>  lib/librte_vhost/vhost.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c
> index 469117a..f5f8f92 100644
> --- a/lib/librte_vhost/vhost.c
> +++ b/lib/librte_vhost/vhost.c
> @@ -65,8 +65,7 @@
>  				(1ULL << VIRTIO_NET_F_CSUM)    | \
>  				(1ULL << VIRTIO_NET_F_GUEST_CSUM) | \
>  				(1ULL << VIRTIO_NET_F_GUEST_TSO4) | \
> -				(1ULL << VIRTIO_NET_F_GUEST_TSO6) | \
> -				(1ULL << VIRTIO_RING_F_INDIRECT_DESC))
> +				(1ULL << VIRTIO_NET_F_GUEST_TSO6))
>
>  uint64_t VHOST_FEATURES = VHOST_SUPPORTED_FEATURES;

I have implemented Indirect descs for the Rx path yesterday.
It deserves more testing, but early tests show it fix the issues found
with VIRTIO_RING_F_INDIRECT_DESC (both with and without mergeable
buffers).


Thanks to Zhihong series you reworked, the changes to be done for
mergeable buffers case is greatly simplified.
I'll send the series later today.

Thanks,
Maxime