[ovs-dev] [PATCH v3 2/4] netdev-offload: Add "offload-driver" other_config to specify offload driver

[William Tu]

On Mon, Jun 29, 2020 at 8:30 AM Toshiaki Makita
<toshiaki.makita1 at gmail.com> wrote:
>
> The following commit will introduce another offload driver using XDP.
> When using afxdp netdev, both of TC and XDP will be supported, so let's
> add an other_config to specify which offload driver is preferable.
> When not specified and multiple offload drivers can be used, TC will be
> used if netdev supports it.
>
> Signed-off-by: Toshiaki Makita <toshiaki.makita1 at gmail.com>
> ---
>  lib/netdev-offload.c | 37 +++++++++++++++++++++++++++++--------
>  1 file changed, 29 insertions(+), 8 deletions(-)
>
> diff --git a/lib/netdev-offload.c b/lib/netdev-offload.c
> index ab97a292e..669513646 100644
> --- a/lib/netdev-offload.c
> +++ b/lib/netdev-offload.c
> @@ -60,6 +60,9 @@ VLOG_DEFINE_THIS_MODULE(netdev_offload);
>
>  static bool netdev_flow_api_enabled = false;
>
> +#define FLOW_API_DRIVER_DEFAULT "linux_tc"
> +static const char *netdev_flow_api_driver = NULL;
> +
>  /* Protects 'netdev_flow_apis'.  */
>  static struct ovs_mutex netdev_flow_api_provider_mutex = OVS_MUTEX_INITIALIZER;
>
> @@ -171,18 +174,30 @@ netdev_flow_api_equals(const struct netdev *netdev1,
>  static int
>  netdev_assign_flow_api(struct netdev *netdev)
>  {
> -    struct netdev_registered_flow_api *rfa;
> +    struct netdev_registered_flow_api *rfa, *current_rfa = NULL;
>
>      CMAP_FOR_EACH (rfa, cmap_node, &netdev_flow_apis) {
> +        if (netdev_flow_api_driver &&
> +            strcmp(netdev_flow_api_driver, rfa->flow_api->type)) {
> +            continue;
> +        }
>          if (!rfa->flow_api->init_flow_api(netdev)) {

IIUC, when using the default linux_tc api driver, the XDP offload driver
will also be init, (netdev_xdp_init_flow_api), right??
Maybe there is a better way to handle this?
Do we need to clean up the resources initialized from the
netdev_xdp_int_flow_api?

William