[PATCH v8 0/3] pcap: support MTU set for linux interfaces

[Ido Goshen <ido@cgstowernetworks.com>]

Support rte_eth_dev_set_mtu for pcap ifaces vdevs by
setting the underlying OS network interface's MTU.
Support is for pcap ifaces only and not for pcap files.
Support is for Linux only.

patch series:
[PATCH v8 1/3] pcap: support MTU set for linux interfaces
[PATCH v8 2/3] pcap: support MTU set for linux interfaces TX
[PATCH v8 3/3] pcap: support MTU set for linux interfaces count

 doc/guides/rel_notes/release_22_07.rst |   3 +
 drivers/net/pcap/pcap_ethdev.c         | 126 +++++++++++++++++++++++++--------
 drivers/net/pcap/pcap_osdep.h          |   1 +
 drivers/net/pcap/pcap_osdep_freebsd.c  |   7 ++
 drivers/net/pcap/pcap_osdep_linux.c    |  21 ++++++
 drivers/net/pcap/pcap_osdep_windows.c  |   7 ++
 6 files changed, 134 insertions(+), 31 deletions(-)

---
v8:
cosmetics only 
1. checkpatch typo fix
2. rel_notes apply patch fix by rebasing on latest main

v7:
1. TX drop only individual oversized packets and not the entire burst
2. Count oversize drops by i/oerrors

v6:
Fixes for v5 approach
1. freebsd compilation fix
2. checkpatch warning fix

v5:
Alternative approach
Instead of checking MTU in the pmd set it on the OS interface and 
let it do the enforcment.

v4:
1. Add release notes comment
2. Access pmd internals via queue struct 
3. eth_mtu_set code convention fixes

v3:
Preserve pcap behavior to support max size packets by default
alternative to v2 in order to limit the code change to pcap only and
avoid abi change.
Enforce mtu only in case rte_eth_dev_set_mtu was explicitly called.

v2:
Preserve pcap behavior to support max size packets by default.