From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andrew Cooper <andrew.cooper3@citrix.com>
Subject: Re: [PATCH V5 01/12] xen/mem_event: Cleanup of
 mem_event structures
Date: Fri, 13 Feb 2015 18:09:28 +0000
Message-ID: <54DE3DD8.40109@citrix.com>
References: <1423845203-18941-1-git-send-email-tamas.lengyel@zentific.com>	<1423845203-18941-2-git-send-email-tamas.lengyel@zentific.com>	<54DE32F7.1030106@citrix.com>
	<CAErYnsjLpCHHzuB_u-bKC-U+16CLH5sb-NR2KnoG-Y9t9VchQQ@mail.gmail.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Return-path: <xen-devel-bounces@lists.xen.org>
In-Reply-To: <CAErYnsjLpCHHzuB_u-bKC-U+16CLH5sb-NR2KnoG-Y9t9VchQQ@mail.gmail.com>
List-Unsubscribe: <http://lists.xen.org/cgi-bin/mailman/options/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=unsubscribe>
List-Post: <mailto:xen-devel@lists.xen.org>
List-Help: <mailto:xen-devel-request@lists.xen.org?subject=help>
List-Subscribe: <http://lists.xen.org/cgi-bin/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=subscribe>
Sender: xen-devel-bounces@lists.xen.org
Errors-To: xen-devel-bounces@lists.xen.org
To: Tamas K Lengyel <tamas.lengyel@zentific.com>
Cc: "Tian, Kevin" <kevin.tian@intel.com>, "wei.liu2@citrix.com" <wei.liu2@citrix.com>, Ian Campbell <ian.campbell@citrix.com>, Razvan Cojocaru <rcojocaru@bitdefender.com>, Stefano Stabellini <stefano.stabellini@eu.citrix.com>, Tim Deegan <tim@xen.org>, Steven Maresca <steve@zentific.com>, "xen-devel@lists.xen.org" <xen-devel@lists.xen.org>, Jan Beulich <jbeulich@suse.com>, "Dong, Eddie" <eddie.dong@intel.com>, Andres Lagar-Cavilla <andres@lagarcavilla.org>, Jun Nakajima <jun.nakajima@intel.com>, "rshriram@cs.ubc.ca" <rshriram@cs.ubc.ca>, Keir Fraser <keir@xen.org>, Daniel De Graaf <dgdegra@tycho.nsa.gov>, "yanghy@cn.fujitsu.com" <yanghy@cn.fujitsu.com>, Ian Jackson <ian.jackson@eu.citrix.com>
List-Id: xen-devel@lists.xenproject.org

On 13/02/15 18:03, Tamas K Lengyel wrote:
> On Fri, Feb 13, 2015 at 6:23 PM, Andrew Cooper
> <andrew.cooper3@citrix.com> wrote:
>> On 13/02/15 16:33, Tamas K Lengyel wrote:
>>> The public mem_event structures used to communicate with helper applications via
>>> shared rings have been used in different settings. However, the variable names
>>> within this structure have not reflected this fact, resulting in the reuse of
>>> variables to mean different things under different scenarios.
>>>
>>> This patch remedies the issue by clearly defining the structure members based on
>>> the actual context within which the structure is used.
>>>
>>> Signed-off-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
>>> Signed-off-by: Tamas K Lengyel <tamas.lengyel@zentific.com>
>>> ---
>>> v5: Style fixes
>>>     Convert gfn to uint32_t
>> It is perfectly possible to have guests with more memory than is covered
>> by 44 bits, or PV guests whose frames reside above the 44bit boundary.
>> All gfn values should be 64bits wide.
>>
>> ~Andrew
> Internally Xen handles all gfn's as unsigned long's so depending on
> the compiler it may be only 32-bit wide. If gfn must be larger than
> 32-bit than we should use unsigned long long's within Xen.

x86_32 Xen support was ripped out a while ago.  For the time being all
unsigned longs are 64bit.

With the arm32/64 split, there is a slow move in the direction of
paddr_t rather than unsigned long.

~Andrew