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Subject: Re: [PATCH] xen: don't use privcmd_call() from xen_mc_flush()
To:     Boris Ostrovsky <boris.ostrovsky@oracle.com>,
        linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org
References: <20180613095806.2978-1-jgross@suse.com>
 <2a9600b0-3b49-7835-a664-9deb30b100a4@suse.com>
 <a4f76a2a-128f-3e2a-44ee-04d57ab5be12@oracle.com>
From:   Juergen Gross <jgross@suse.com>
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Message-ID: <ff2b390c-3b4f-67c4-5a1c-35be121fe281@suse.com>
Date:   Tue, 7 Aug 2018 17:17:02 +0200
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On 07/08/18 16:02, Boris Ostrovsky wrote:
> On 08/07/2018 09:11 AM, Juergen Gross wrote:
>> On 13/06/18 11:58, Juergen Gross wrote:
>>> Using privcmd_call() for a singleton multicall seems to be wrong, as
>>> privcmd_call() is using stac()/clac() to enable hypervisor access to
>>> Linux user space.
>>>
>>> Add a new xen_single_call() function to be use for that purpose.
>>>
>>> Reported-by: Jan Beulich <jbeulich@suse.com>
>>> Signed-off-by: Juergen Gross <jgross@suse.com>
>> Boris, any objections?
> 
> 
> I think Jan wanted a change in commit message. I can commit with this:
> 
> "Using privcmd_call() for a singleton multicall seems to be wrong, as
>  privcmd_call() is using stac()/clac() to enable hypervisor access to
>  Linux user space.
> 
>  Even if currently not a problem (pv domains can't use SMAP while HVM
>  and PVH domains can't use multicalls) things might change when
>  PVH dom0 support is added to the kernel."

This would be fine, thanks.


Juergen