From mboxrd@z Thu Jan  1 00:00:00 1970
From: =?windows-1252?Q?Roger_Pau_Monn=E9?= <roger.pau@citrix.com>
Subject: Re: [PATCH v3 2/3] xen/shadow: fix
 shadow_track_dirty_vram to work on hvm guests
Date: Wed, 6 May 2015 17:12:38 +0200
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To: Jan Beulich <JBeulich@suse.com>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>, Tim Deegan <tim@xen.org>, xen-devel@lists.xenproject.org
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El 14/04/15 a les 14.22, Jan Beulich ha escrit:
>>>> On 10.04.15 at 19:29, <roger.pau@citrix.com> wrote:
>> Modify shadow_track_dirty_vram to use a local buffer and then flush to the
>> guest without the paging_lock held. This is modeled after
>> hap_track_dirty_vram.
> 
> And hence introduces the same issue: The HVMOP_track_dirty_vram
> handler explicitly allows for up to 1Gb of VRAM, yet here you
> effectively limit things to 128Mb (one page worth of bits each taking
> care of one guest page) considering heavily fragmented memory.

Where does this limitation come from? We allocate a temporary bitmap
that has enough size to accommodate for the number of entries passed to
the function in nr.

I guess there's some limitation I'm not seeing.

Roger.