From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Vrabel <david.vrabel@citrix.com>
Subject: [RFC PATCH 0/8] Xen: FIFO-based event channel ABI
Date: Fri, 9 Aug 2013 19:08:32 +0100
Message-ID: <1376071720-17644-1-git-send-email-david.vrabel@citrix.com>
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Cc: Wei Liu <wei.liu2@citrix.com>, Keir Fraser <keir@xen.org>, David Vrabel <david.vrabel@citrix.com>
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This is an RFC of the FIFO-based event channel ABI described in this
design document:

http://xenbits.xen.org/people/dvrabel/event-channels-D.pdf

Changes in draft D include:

- Only Xen writes to the HEAD field in the control block

- Added a link_bits field to EVTCHNOP_init_control to return the
  number of valid bits for the LINK field.

Patch 1-4 do some preparatory work for supporting alternate ABIs.

Patch 5-8 expand the number of evtchn objects a domain may have to
changing how they are allocated.

Patch 7-8 add the ABI and the implementation.  Patch 8 list some of
the known limitations with this RFC implementation.

Changes in v1:

- Updates for Draft D of the design.
- 130,000+ event channels are now supported.
- event_port.c -> event_2l.c and only contains 2l functions.
- Addresses various review comments
  - int -> unsigned in lots of places
  - use write_atomic() to set HEAD
  - removed MAX_EVTCHNS
  - evtchn_ops are const.
- Pack struct evtchns better to reduce memory needed.

David