From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ian Campbell <Ian.Campbell@citrix.com>
Subject: Re: [PATCH] set pv guest default video_memkb to 0
Date: Thu, 20 Nov 2014 15:29:51 +0000
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To: Wei Liu <wei.liu2@citrix.com>
Cc: xen-devel@lists.xenproject.org, Zhigang Wang <zhigang.x.wang@oracle.com>, ian.jackson@eu.citrix.com
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On Wed, 2014-11-19 at 21:24 +0000, Wei Liu wrote:
> On Wed, Nov 19, 2014 at 04:08:46PM -0500, Konrad Rzeszutek Wilk wrote:
> > On Tue, Nov 18, 2014 at 03:57:08PM -0500, Zhigang Wang wrote:
> > > Before this patch, pv guest video_memkb is -1, which is an invalid value.
> > > And it will cause the xenstore 'memory/targe' calculation wrong:
> > > 
> > >     memory/target = info->target_memkb - info->video_memkb
> > 
> > CC-ing the maintainers.
> > 
> > Is this an regression as compared to Xen 4.4 or is this also in Xen 4.4?
> > 
> 
> I don't think this is a regression, it has been broken for quite a
> while.

I think so to.

On the other hand its a pretty clear bug to use video_memkb == -1 and
we've seen that it causes real issues. The fix is also fairly obvious.
I'm inclined towards suggesting we fix this in 4.5.

Ian.