Hi
>
> Vector RX functions are not at feature parity with non-vector ones and
> currently the vector RX path is enabled by default. Hence, the only
> option to force selection of non-vector variants and be able to retain
> functionality is to disable vector PMD globally at compile time via the
> config file option.
>
> This patch introduces a new runtime device config option named
> disable-vec-rx to allow users to limit the driver to make a choice among
> non-vector RX functions, on a per device basis. This runtime option
> defaults to a value of zero, allowing vector RX functions to be
> selected (current behavior). When disable-vec-rx=1 is specified for a
> device, even if all the other requirements to select a vector RX
> function are satisfied, the driver will still pick one out of the
> appropriate non-vector RX functions.
Not sure I understand the logic of that patch.
If i40e RX PMD selects wrong RX function that doesn't provide
requested by user functionality (which one?) -
then it is a bug in i40e RX function selection code that needs to be fixed.
No point to introduce some new config options for that.
Konstantin
>
> Signed-off-by: Mesut Ali Ergin <mesut.a.er...@intel.com>
> ---
> doc/guides/nics/i40e.rst | 14 +++++++++
> drivers/net/i40e/i40e_ethdev.c | 70
> +++++++++++++++++++++++++++++++++++++++++-
> drivers/net/i40e/i40e_ethdev.h | 1 +
> drivers/net/i40e/i40e_rxtx.c | 4 +++
> 4 files changed, 88 insertions(+), 1 deletion(-)
>
> diff --git a/doc/guides/nics/i40e.rst b/doc/guides/nics/i40e.rst
> index a97484c..532cc64 100644
> --- a/doc/guides/nics/i40e.rst
> +++ b/doc/guides/nics/i40e.rst
> @@ -183,6 +183,20 @@ Runtime Config Options
>
> -w 84:00.0,use-latest-supported-vec=1
>
> +- ``Disable RX Vector Functions `` (default ``vector RX enabled``)
> +
> + When config file option for the vector PMD is enabled, vector RX functions
> may
> + be the default choice of the driver at device initialization time, if
> certain
> + conditions apply. However, vector RX functions may not always be at feature
> + parity with non-vector ones. In order to allow users to override vector RX
> + function selection behavior at runtime, the ``devargs`` parameter
> + ``disable-vec-rx`` is introduced, such that
> +
> + -w DBDF,disable-vec-rx=1
> +
> + would force driver to limit its choices to non-vector RX function variants
> for
> + the device specified by the DBDF.
> +
> Vector RX Pre-conditions
> ~~~~~~~~~~~~~~~~~~~~~~~~
> For Vector RX it is assumed that the number of descriptor rings will be a
> power
> diff --git a/drivers/net/i40e/i40e_ethdev.c b/drivers/net/i40e/i40e_ethdev.c
> index cab440f..19fbd23 100644
> --- a/drivers/net/i40e/i40e_ethdev.c
> +++ b/drivers/net/i40e/i40e_ethdev.c
> @@ -44,6 +44,7 @@
> #define ETH_I40E_SUPPORT_MULTI_DRIVER "support-multi-driver"
> #define ETH_I40E_QUEUE_NUM_PER_VF_ARG "queue-num-per-vf"
> #define ETH_I40E_USE_LATEST_VEC "use-latest-supported-vec"
> +#define ETH_I40E_DISABLE_VEC_RX "disable-vec-rx"
>
> #define I40E_CLEAR_PXE_WAIT_MS 200
>
> @@ -410,6 +411,7 @@ static const char *const valid_keys[] = {
> ETH_I40E_SUPPORT_MULTI_DRIVER,
> ETH_I40E_QUEUE_NUM_PER_VF_ARG,
> ETH_I40E_USE_LATEST_VEC,
> + ETH_I40E_DISABLE_VEC_RX,
> NULL};
>
> static const struct rte_pci_id pci_id_i40e_map[] = {
> @@ -1263,6 +1265,68 @@ i40e_use_latest_vec(struct rte_eth_dev *dev)
> return 0;
> }
>
> +static int
> +i40e_parse_disable_vec_rx_handler(__rte_unused const char *key,
> + const char *value,
> + void *opaque)
> +{
> + struct i40e_adapter *ad;
> +
> + ad = (struct i40e_adapter *)opaque;
> +
> + switch (atoi(value)) {
> + case 0:
> + /* Selection of RX vector functions left untouched*/
> + break;
> + case 1:
> + /* Disable RX vector functions as requested*/
> + ad->rx_vec_allowed = false;
> + break;
> + default:
> + PMD_DRV_LOG(WARNING, "Value should be 0 or 1, set it as 1!");
> + break;
> + }
> +
> + return 0;
> +}
> +
> +int
> +i40e_disable_vec_rx(struct rte_eth_dev *dev)
> +{
> + struct i40e_adapter *ad =
> + I40E_DEV_PRIVATE_TO_ADAPTER(dev->data->dev_private);
> + struct rte_kvargs *kvlist;
> + int kvargs_count;
> +
> +
> + if (!dev->device->devargs)
> + return 0;
> +
> + kvlist = rte_kvargs_parse(dev->device->devargs->args, valid_keys);
> + if (!kvlist)
> + return -EINVAL;
> +
> + kvargs_count = rte_kvargs_count(kvlist, ETH_I40E_DISABLE_VEC_RX);
> + if (!kvargs_count) {
> + rte_kvargs_free(kvlist);
> + return 0;
> + }
> +
> + if (kvargs_count > 1)
> + PMD_DRV_LOG(WARNING, "More than one argument \"%s\" and only "
> + "the first invalid or last valid one is used !",
> + ETH_I40E_DISABLE_VEC_RX);
> +
> + if (rte_kvargs_process(kvlist, ETH_I40E_DISABLE_VEC_RX,
> + i40e_parse_disable_vec_rx_handler, ad) < 0) {
> + rte_kvargs_free(kvlist);
> + return -EINVAL;
> + }
> +
> + rte_kvargs_free(kvlist);
> + return 0;
> +}
> +
> #define I40E_ALARM_INTERVAL 50000 /* us */
>
> static int
> @@ -1795,6 +1859,9 @@ i40e_dev_configure(struct rte_eth_dev *dev)
> ad->tx_simple_allowed = true;
> ad->tx_vec_allowed = true;
>
> + /* Check if users wanted to disable vector RX functions */
> + i40e_disable_vec_rx(dev);
> +
> /* Only legacy filter API needs the following fdir config. So when the
> * legacy filter API is deprecated, the following codes should also be
> * removed.
> @@ -12790,4 +12857,5 @@ RTE_PMD_REGISTER_PARAM_STRING(net_i40e,
> ETH_I40E_FLOATING_VEB_LIST_ARG "=<string>"
> ETH_I40E_QUEUE_NUM_PER_VF_ARG "=1|2|4|8|16"
> ETH_I40E_SUPPORT_MULTI_DRIVER "=1"
> - ETH_I40E_USE_LATEST_VEC "=0|1");
> + ETH_I40E_USE_LATEST_VEC "=0|1"
> + ETH_I40E_DISABLE_VEC_RX "=0|1");
> diff --git a/drivers/net/i40e/i40e_ethdev.h b/drivers/net/i40e/i40e_ethdev.h
> index 9855038..906bfe9 100644
> --- a/drivers/net/i40e/i40e_ethdev.h
> +++ b/drivers/net/i40e/i40e_ethdev.h
> @@ -1248,6 +1248,7 @@ int i40e_config_rss_filter(struct i40e_pf *pf,
> struct i40e_rte_flow_rss_conf *conf, bool add);
> int i40e_vf_representor_init(struct rte_eth_dev *ethdev, void *init_params);
> int i40e_vf_representor_uninit(struct rte_eth_dev *ethdev);
> +int i40e_disable_vec_rx(struct rte_eth_dev *dev);
>
> #define I40E_DEV_TO_PCI(eth_dev) \
> RTE_DEV_TO_PCI((eth_dev)->device)
> diff --git a/drivers/net/i40e/i40e_rxtx.c b/drivers/net/i40e/i40e_rxtx.c
> index 1489552..7e66f59 100644
> --- a/drivers/net/i40e/i40e_rxtx.c
> +++ b/drivers/net/i40e/i40e_rxtx.c
> @@ -1736,6 +1736,10 @@ i40e_dev_rx_queue_setup_runtime(struct rte_eth_dev
> *dev,
> */
> ad->rx_bulk_alloc_allowed = true;
> ad->rx_vec_allowed = true;
> +
> + /* Check if users wanted to disable vector RX functions */
> + i40e_disable_vec_rx(dev);
> +
> dev->data->scattered_rx = use_scattered_rx;
> if (use_def_burst_func)
> ad->rx_bulk_alloc_allowed = false;
> --
> 2.7.4
