[dpdk-dev] [PATCH v2] vhost: prevent disabled rings to be processed with zero-copy
maxime.coquelin at redhat.com
Thu Mar 21 10:11:35 CET 2019
On 2/28/19 6:57 PM, Maxime Coquelin wrote:
> The vhost-user spec says that once the vring is disabled, the
> client has to stop processing it. But it can happen when
> dequeue zero-copy is enabled if outstanding descriptors buffers
> are still being processed by an external NIC or another guest.
> The fix consists in draining the zmbufs list to ensure no more
> descriptors buffers are in the wild.
> Note that this fix is only working in the case REPLY_ACK
> protocol feature is enabled, which is not the case by default
> for now (it is only enabled when IOMMU feature is enabled in
> the vhost library).
> Fixes: b0a985d1f340 ("vhost: add dequeue zero copy")
> Cc: stable at dpdk.org
> Reviewed-by: Tiwei Bie <tiwei.bie at intel.com>
> Signed-off-by: Maxime Coquelin <maxime.coquelin at redhat.com>
> lib/librte_vhost/vhost_user.c | 4 ++++
> 1 file changed, 4 insertions(+)
> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
> index 36c0c676d..555d09ad9 100644
> --- a/lib/librte_vhost/vhost_user.c
> +++ b/lib/librte_vhost/vhost_user.c
> @@ -1345,6 +1345,10 @@ vhost_user_set_vring_enable(struct virtio_net **pdev,
> index, enable);
> + /* On disable, rings have to be stopped being processed. */
> + if (!enable && dev->dequeue_zero_copy)
> + drain_zmbuf_list(dev->virtqueue[index]);
> dev->virtqueue[index]->enabled = enable;
> return RTE_VHOST_MSG_RESULT_OK;
Applied to dpdk-next-virtio/master.
More information about the dev