Re: [dpdk-dev] [PATCH v5 06/11] net/virtio-user: add option to use packed queues

[Maxime Coquelin <maxime.coquelin@redhat.com>]

On 09/06/2018 08:19 PM, Jens Freimann wrote:
> From: Yuanhan Liu <yuanhan.liu@linux.intel.com>
> 
> Add option to enable packed queue support for virtio-user
> devices.
> 
> Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
> ---
>   drivers/net/virtio/virtio_user/virtio_user_dev.c | 10 ++++++++--
>   drivers/net/virtio/virtio_user/virtio_user_dev.h |  2 +-
>   drivers/net/virtio/virtio_user_ethdev.c          | 14 +++++++++++++-
>   3 files changed, 22 insertions(+), 4 deletions(-)


Shouldn't this patch be better placed at the end of the series to avoid
negotiating packed ring feature while the datapaths aren't implemented?

> diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c b/drivers/net/virtio/virtio_user/virtio_user_dev.c
> index 7df600b02..9979bea0d 100644
> --- a/drivers/net/virtio/virtio_user/virtio_user_dev.c
> +++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c
> @@ -372,12 +372,13 @@ virtio_user_dev_setup(struct virtio_user_dev *dev)
>   	 1ULL << VIRTIO_NET_F_GUEST_TSO4	|	\
>   	 1ULL << VIRTIO_NET_F_GUEST_TSO6	|	\
>   	 1ULL << VIRTIO_F_IN_ORDER		|	\
> -	 1ULL << VIRTIO_F_VERSION_1)
> +	 1ULL << VIRTIO_F_VERSION_1		|	\
> +	 1ULL << VIRTIO_F_RING_PACKED)
>   
>   int
>   virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
>   		     int cq, int queue_size, const char *mac, char **ifname,
> -		     int mrg_rxbuf, int in_order)
> +		     int mrg_rxbuf, int in_order, int packed_vq)
>   {
>   	pthread_mutex_init(&dev->mutex, NULL);
>   	snprintf(dev->path, PATH_MAX, "%s", path);
> @@ -432,6 +433,11 @@ virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
>   		dev->unsupported_features |= (1ull << VIRTIO_F_IN_ORDER);
>   	}
>   
> +	if (packed_vq)
> +		dev->device_features |= (1ull << VIRTIO_F_RING_PACKED);
> +	else
> +		dev->device_features &= ~(1ull << VIRTIO_F_RING_PACKED);
> +
>   	if (dev->mac_specified) {
>   		dev->device_features |= (1ull << VIRTIO_NET_F_MAC);
>   	} else {
> diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.h b/drivers/net/virtio/virtio_user/virtio_user_dev.h
> index d6e0e137b..7f46ba1d9 100644
> --- a/drivers/net/virtio/virtio_user/virtio_user_dev.h
> +++ b/drivers/net/virtio/virtio_user/virtio_user_dev.h
> @@ -49,7 +49,7 @@ int virtio_user_start_device(struct virtio_user_dev *dev);
>   int virtio_user_stop_device(struct virtio_user_dev *dev);
>   int virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
>   			 int cq, int queue_size, const char *mac, char **ifname,
> -			 int mrg_rxbuf, int in_order);
> +			 int mrg_rxbuf, int in_order, int packed_vq);
>   void virtio_user_dev_uninit(struct virtio_user_dev *dev);
>   void virtio_user_handle_cq(struct virtio_user_dev *dev, uint16_t queue_idx);
>   uint8_t virtio_user_handle_mq(struct virtio_user_dev *dev, uint16_t q_pairs);
> diff --git a/drivers/net/virtio/virtio_user_ethdev.c b/drivers/net/virtio/virtio_user_ethdev.c
> index 525d16cab..72ac86186 100644
> --- a/drivers/net/virtio/virtio_user_ethdev.c
> +++ b/drivers/net/virtio/virtio_user_ethdev.c
> @@ -364,6 +364,8 @@ static const char *valid_args[] = {
>   	VIRTIO_USER_ARG_MRG_RXBUF,
>   #define VIRTIO_USER_ARG_IN_ORDER       "in_order"
>   	VIRTIO_USER_ARG_IN_ORDER,
> +#define VIRTIO_USER_ARG_PACKED_VQ "packed_vq"
> +	VIRTIO_USER_ARG_PACKED_VQ,
>   	NULL
>   };
>   
> @@ -473,6 +475,7 @@ virtio_user_pmd_probe(struct rte_vdev_device *dev)
>   	char *ifname = NULL;
>   	char *mac_addr = NULL;
>   	int ret = -1;
> +	uint64_t packed_vq = 0;
>   
>   	kvlist = rte_kvargs_parse(rte_vdev_device_args(dev), valid_args);
>   	if (!kvlist) {
> @@ -556,6 +559,15 @@ virtio_user_pmd_probe(struct rte_vdev_device *dev)
>   		cq = 1;
>   	}
>   
> +	if (rte_kvargs_count(kvlist, VIRTIO_USER_ARG_PACKED_VQ) == 1) {
> +		if (rte_kvargs_process(kvlist, VIRTIO_USER_ARG_PACKED_VQ,
> +				       &get_integer_arg, &packed_vq) < 0) {
> +			PMD_INIT_LOG(ERR, "error to parse %s",
> +				     VIRTIO_USER_ARG_PACKED_VQ);
> +			goto end;
> +		}
> +	}
> +
>   	if (queues > 1 && cq == 0) {
>   		PMD_INIT_LOG(ERR, "multi-q requires ctrl-q");
>   		goto end;
> @@ -603,7 +615,7 @@ virtio_user_pmd_probe(struct rte_vdev_device *dev)
>   			vu_dev->is_server = false;
>   		if (virtio_user_dev_init(hw->virtio_user_dev, path, queues, cq,
>   				 queue_size, mac_addr, &ifname, mrg_rxbuf,
> -				 in_order) < 0) {
> +				 in_order, packed_vq) < 0) {
>   			PMD_INIT_LOG(ERR, "virtio_user_dev_init fails");
>   			virtio_user_eth_dev_free(eth_dev);
>   			goto end;
>