From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jeremy Fitzhardinge <jeremy@goop.org>
Subject: Re: pv_ops & gntdev?
Date: Wed, 25 Feb 2009 09:51:02 -0800
Message-ID: <49A58506.2020407@goop.org>
References: <49A44030.2070709@redhat.com> <49A4640E.1000807@goop.org>
	<49A470DD.2000008@redhat.com> <49A517F6.30005@redhat.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Return-path: <xen-devel-bounces@lists.xensource.com>
In-Reply-To: <49A517F6.30005@redhat.com>
List-Unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
List-Post: <mailto:xen-devel@lists.xensource.com>
List-Help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-Subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
Sender: xen-devel-bounces@lists.xensource.com
Errors-To: xen-devel-bounces@lists.xensource.com
To: Gerd Hoffmann <kraxel@redhat.com>
Cc: Xen Development Mailing List <xen-devel@lists.xensource.com>
List-Id: xen-devel@lists.xenproject.org

Gerd Hoffmann wrote:
> Gerd Hoffmann wrote:
>   
>>> Do you want to bring it over?
>>>       
>> Well.  I hoped someone did that already ...
>>     
>
> Ideas how to handle the grant unmap case?
> I suspect the vm_ops->zap_pte() approach isn't going to fly for mainline
> merge ...

Yes, my plan is:

   1. when installing a grant in a pte page, allocate a shadow page and
      hang it off page->private; also set a page flag on the pgd page
      flags (steal something spare)
   2. store the grant handle in the slot corresponding to the pte
   3. when clearing the pte, check to see if there's a grant handle and
      zap it
   4. when unpinning the pagetable, check to see if there's the "grant
      mapping" flag in the pgd, and do a grant-zap pass before unpinning

    J