From mboxrd@z Thu Jan  1 00:00:00 1970
From: George Dunlap <george.dunlap@citrix.com>
Subject: Re: [PATCH v2 5/5] libxl: Add explicit cast to
	libxl_psr_cat_set_cbm
Date: Tue, 19 Jan 2016 14:31:07 +0000
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To: Ian Campbell <ian.campbell@citrix.com>, Ian Jackson <Ian.Jackson@eu.citrix.com>, Chester Lin <czylin@uwaterloo.ca>
Cc: stefano.stabellini@eu.citrix.com, george.dunlap@eu.citrix.com, dario.faggioli@citrix.com, xen-devel@lists.xen.org, jtotto@uwaterloo.ca, hjarmstr@uwaterloo.ca
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On 19/01/16 14:21, Ian Campbell wrote:
> On Tue, 2016-01-19 at 14:06 +0000, Ian Jackson wrote:
>> I am not a fan of the cast as a solution.  I would rather, prefer to
>> regularise the situation.  If my co-maintainers agree about the
>> desirability of expecting libxl callers to use enum values from Xen
>> public headers,
<snip>
> I think part of the problem is that it is hard to expose just the desired
> bits through to the user of libxl without also exposing the full xen
> hypercall interface (the vast majority of which would be inappropriate to
> expose to them since libxl is suppose to encapsulate such things).

I agree with this sentiment...

> As a possible alternative, we could make it such that the IDL generator
> knows about the linkage and enforces the use of the same values, and
> automatically provides conversion helpers (essential a cast wrapped in some
> syntax) for _internal_ use.

...and using the IDL to enforce or generate values was my first thought.

 -George