From: Keir Fraser <keir.xen@gmail.com>
To: Justin Gibbs <justing@spectralogic.com>, Jan Beulich <JBeulich@suse.com>
Cc: "<xen-devel@lists.xensource.com>" <xen-devel@lists.xensource.com>
Subject: Re: [PATCH 5 of 5] blkif.h: Define and document the request number/size/segments extension
Date: Tue, 07 Feb 2012 13:49:18 +0000 [thread overview]
Message-ID: <CB56DC5E.2A92B%keir.xen@gmail.com> (raw)
In-Reply-To: <7FAA6F15-2ECE-403F-A115-9687299A8BE7@spectralogic.com>
On 07/02/2012 21:45, "Justin Gibbs" <justing@spectralogic.com> wrote:
>> NAK. No backwards incompatible changes allowed in public headers.
>
> Sorry for the slow reply on this. I've been experimenting with ways to keep
> legacy
> source compatibility. After trying lots of things, testing the impact on an
> existing blkfront
> and blkback implementation, I think the best two options are:
>
> 1. Version the header file and require consumers to declare the interface
> version
> they are using. If the version isn't declared, the default, legacy,
> "version 1.0" will
> be in effect.
>
> Positives: No change in or constant naming conventions. Data
> structures and
> constants for new features are properly hidden from
> legacy implementations.
> Negatives: Messy #ifdefs
We already have this. See use of
__XEN_INTERFACE_VERSION__/__XEN_LATEST_INTERFACE_VERSION__ in the public
headers.
-- Keir
next prev parent reply other threads:[~2012-02-07 13:49 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-03 5:24 [PATCH 0 of 5] blkif.h: Document protocol and existing extensions Justin T. Gibbs
2012-02-03 5:24 ` [PATCH 1 of 5] blkif.h: Miscelaneous style fixes Justin T. Gibbs
2012-02-09 9:30 ` Ian Campbell
2012-02-03 5:24 ` [PATCH 2 of 5] blkif.h: Provide more complete documentation of the blkif interface Justin T. Gibbs
2012-02-07 17:51 ` Ian Jackson
2012-02-08 23:24 ` Justin T. Gibbs
2012-02-09 9:36 ` Ian Campbell
2012-02-09 15:19 ` Ian Jackson
2012-02-03 5:24 ` [PATCH 3 of 5] blkif.h: Add definitions for virtual block device major numbers Justin T. Gibbs
2012-02-03 13:31 ` Jan Beulich
2012-02-03 15:49 ` Justin Gibbs
2012-02-09 9:46 ` Ian Campbell
2012-02-09 10:05 ` Paul Durrant
2012-02-09 16:41 ` Justin T. Gibbs
2012-02-07 17:33 ` Ian Jackson
2012-02-08 23:12 ` Justin T. Gibbs
2012-02-09 15:17 ` Ian Jackson
2012-02-09 16:40 ` Justin T. Gibbs
2012-02-09 16:52 ` Ian Jackson
2012-02-09 17:02 ` Ian Campbell
2012-02-03 5:24 ` [PATCH 4 of 5] blkif.h: Document the RedHat and Citrix blkif multi-page ring extensions Justin T. Gibbs
2012-02-03 13:33 ` Jan Beulich
2012-02-03 14:58 ` Justin Gibbs
2012-02-03 15:01 ` Jan Beulich
2012-02-03 15:19 ` Justin Gibbs
2012-02-03 16:12 ` Jan Beulich
2012-02-08 22:00 ` Justin T. Gibbs
2012-02-09 9:15 ` Jan Beulich
2012-02-09 14:56 ` Justin T. Gibbs
2012-02-09 9:48 ` Ian Campbell
2012-02-09 10:36 ` Jan Beulich
2012-02-09 10:40 ` Ian Campbell
2012-02-09 15:12 ` Justin T. Gibbs
2012-02-13 12:35 ` Ian Campbell
2012-02-14 13:56 ` Konrad Rzeszutek Wilk
2012-02-15 6:51 ` Justin T. Gibbs
2012-02-15 13:07 ` Justin T. Gibbs
2012-02-15 13:32 ` Ian Campbell
2012-02-03 5:24 ` [PATCH 5 of 5] blkif.h: Define and document the request number/size/segments extension Justin T. Gibbs
2012-02-03 13:34 ` Jan Beulich
2012-02-07 21:45 ` Justin Gibbs
2012-02-07 13:49 ` Keir Fraser [this message]
2012-02-08 7:48 ` Jan Beulich
2012-02-08 6:00 ` Keir Fraser
2012-02-08 16:20 ` Jan Beulich
2012-02-09 6:22 ` Justin T. Gibbs
2012-02-09 9:25 ` Jan Beulich
2012-02-09 12:44 ` Keir Fraser
2012-02-09 14:45 ` Justin T. Gibbs
2012-02-09 12:32 ` Keir Fraser
2012-02-08 7:49 ` Jan Beulich
2012-02-03 9:52 ` [PATCH 0 of 5] blkif.h: Document protocol and existing extensions Jan Beulich
2012-02-09 9:29 ` Ian Campbell
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