[dpdk-dev] [RFC] ethdev: use special speed for virtual Ethernet devices

[Morten Brørup]

Thomas, Ferruh, Andrew (Ethernet API Maintainers),

A command line option was recently added to set which speed a vNIC reports when the link is up. This makes sense for Spanning Tree and other protocols which depend on link speed.

However, I suspect that this workaround rarely reflects the physical truth, and suggest that the application should handle it instead.

In other words... Instead of faking it in the virtual Ethernet drivers, I suggest that rte_ethdev.h defines a special speed value for vNICs which really don't have a physical link speed:

#define ETH_SPEED_NUM_NONE         0 /**< Not defined */
+#define ETH_SPEED_NUM_UNKNOWN      1 /**< Unknown (virtual device) */
#define ETH_SPEED_NUM_10M         10 /**<  10 Mbps */

Alternatively, we could expand the meaning of ETH_SPEED_NUM_NONE:

-#define ETH_SPEED_NUM_NONE         0 /**< Not defined */
+#define ETH_SPEED_NUM_NONE         0 /**< Not defined or unknown (virtual device) */

The special value could also be used in cases like this:
http://inbox.dpdk.org/dev/AM0PR0502MB401907ADE7CEA27DC642DF35D2CB0@AM0PR0502MB4019.eurprd05.prod.outlook.com/T/#t


Med venlig hilsen / kind regards
- Morten Brørup