From mboxrd@z Thu Jan  1 00:00:00 1970
From: Julien Grall <julien.grall@citrix.com>
Subject: Re: [PATCH] VT-d: add iommu=igfx_off option to
 workaround graphics issues
Date: Sun, 19 Jul 2015 16:53:59 +0100
Message-ID: <55ABC817.5030601@citrix.com>
References: <1437159952-4134-1-git-send-email-lantw44@gmail.com>
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To: Ting-Wei Lan <lantw44@gmail.com>, xen-devel@lists.xen.org
Cc: Yang Zhang <yang.z.zhang@intel.com>, Kevin Tian <kevin.tian@intel.com>, Jan Beulich <jbeulich@suse.com>
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Hi,

On 17/07/2015 20:05, Ting-Wei Lan wrote:
> When using Linux >= 3.19 (commit 47591df) as dom0 on some Intel Ironlake
> devices, It is possible to encounter graphics issues that make screen
> unreadable or crash the system. It was reported in freedesktop bugzilla:
>
> https://bugs.freedesktop.org/show_bug.cgi?id=90037
>
> As we still cannot find a proper fix for this problem, this patch adds
> iommu=igfx_off option that is similar to Linux intel_iommu=igfx_off for
> users to manually workaround the problem.

I would prefer to see the introduction of intel_iommu parameter in the 
vtd code rather than extending again the iommu parameter with intel 
specific options in the common code which is both for ARM and x86.

Regards,

-- 
Julien Grall