[Differential] [Request, 152 lines] D1644: Add infrastructure for handling the VC msg channel from VFs

[rstone (Ryan Stone)]

rstone created this revision.
rstone added a reviewer: jfvogel.
rstone added a subscriber: freebsd-net.

REVISION SUMMARY
  The VF drivers do not have unrestricted access to the hardware.
  To configure the VF (e.g. set the MAC address), they are required
  to send a message the PF requesting the configuration.  These
  messages are passed over the "Virtual Channel" (VC).  Add the
  infrastructure required to receive Admin Queue interrupts
  indicating that a VC message has been received.  Also add functions
  for sending responses back to the VFs.
  
  At this stage no VC messages are actually handled.  Implementation
  of individual VC messages will be added in subsequent commits.

REVISION DETAIL
  https://reviews.freebsd.org/D1644

AFFECTED FILES
  sys/dev/ixl/if_ixl.c
  sys/dev/ixl/ixl_pf.h

To: rstone, jfvogel
Cc: freebsd-net