From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andrew Cooper <andrew.cooper3@citrix.com>
Subject: Re: Issues regarding "mem_access: Add helper API to
 setup ring and enable mem_access"
Date: Mon, 30 Jun 2014 14:07:41 +0100
Message-ID: <53B1611D.2080502@citrix.com>
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To: Ian Campbell <Ian.Campbell@citrix.com>, Ian Jackson <Ian.Jackson@eu.citrix.com>
Cc: Tamas Lengyel <tamas.lengyel@zentific.com>, "xen-devel@lists.xen.org" <xen-devel@lists.xen.org>, Aravindh Puthiyaparambil <aravindp@cisco.com>
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On 30/06/14 13:44, Ian Campbell wrote:
> On Mon, 2014-06-30 at 13:42 +0100, Ian Jackson wrote:
>> Tamas Lengyel writes ("Re: [Xen-devel] Issues regarding "mem_access: Add helper API to setup ring and enable mem_access""):
>>>     > Now with this function being reintroduced, it becomes more complicated
>>>     > to determine which version of the mem_access API does Xen actually
>>>     > provide. A #define indicating mem_access API version would nicely
>>>     > overcome this issue, or  naming xc_mem_event_enable something else.
>>>
>>>     Doesn't configure support checking for functions with a given prototype?
>>>
>>> It does but in a very hacky way, essentially trying to compile code where the
>>> function is being called with different prototypes. We can work around it but a
>>> clean solution would be preferred at some point.
>> I agree with your criticism, TBH.  Aravindh/Ian, can we rename this
>> function ?
> I have no objection to some other name.
>
>>> This is now a rather opaque behavior of libxc. As it is not merged
>>> into master I guess I will just submit a patch for it..
>> Yes.  I think this would be the right approach to addressing both of
>> these problems.  (Please send two patches, one for each.)
>>
>> Thanks,
>> Ian.

There is a bug in Xen.  domctl pause and unpause hypercalls are not
properly refcounted.  Patch on its way.

~Andrew