From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: Guidelines for new PV protocol submission Date: Tue, 20 Jan 2015 14:00:17 +0000 Message-ID: <54BE5F71.6000303@citrix.com> References: <54BE4E6A.8010102@citrix.com> <54BE562B.40601@citrix.com> <54BE5AAF.6020709@citrix.com> <54BE6ACA020000780005711A@mail.emea.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta4.messagelabs.com ([85.158.143.247]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1YDZMr-0000au-In for xen-devel@lists.xenproject.org; Tue, 20 Jan 2015 14:01:17 +0000 In-Reply-To: <54BE6ACA020000780005711A@mail.emea.novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Jan Beulich Cc: Ian Campbell , Stefano Stabellini , oleksandr.dmytryshyn@globallogic.com, Ian Jackson , David Vrabel , xen-devel , roger.pau@citrix.com List-Id: xen-devel@lists.xenproject.org On 20/01/15 13:48, Jan Beulich wrote: >>>> On 20.01.15 at 14:39, wrote: >> It is far nicer to work from a document than to worry how another >> compiler might change the structure. > Compilers have (almost, i.e. leaving aside bitfields) no freedom in laying > out structures - any platform's ABI defines how this needs to be done. > Or else code compiled with different compilers wouldn't inter-operate. Widths of types are not consistent. Attempting to use the Xen header files on windows requires sed because unsigned longs are still 32 bits even on 64bit windows. (i.e. an unsigned long is not valid for a pointer of natural width, which occurs even in the HVM ABI). Assuming a posix view of the world is not good enough for the Xen ecosystem, which is why a document is preferable to a C structure. ~Andrew