SnabbCo/snabbswitch — pull request #274 by javierguerragiraldez (2014-09-29 05:49:27+00:00)
Title: Intel10g: rx_buffsize config and check

This is supposed to fix #272
- driver: The config parameter `rx_buffsize` is used to set the receive queue buffer size (rounded down to KB increments and clipped to 16KB max)
- driver: Before adding a buffer to the descriptor ring `rxdesc`, the size is `assert()`'ed to be big enough.
- intel_app: Before accepting a given `rx_freelist`, each buffer in it is checked for minimum size.

I don't know if the virtio app can switch from zero-copy to non-optimized at any time, so i opted for checking the whole freelist immediately, and ignoring it if it's not acceptable.