Re: [PATCH v4] VT-d: add iommu=igfx option to workaround graphics issues

[Ian Campbell <ian.campbell@citrix.com>]

On Thu, 2015-08-06 at 09:25 +0100, Wei Liu wrote:
> On Thu, Aug 06, 2015 at 12:49:51AM +0000, Tian, Kevin wrote:
> > > From: Ting-Wei Lan [mailto:lantw44@gmail.com]
> > > Sent: Thursday, August 06, 2015 1:10 AM
> > > 
> > > 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 option to control whether Intel graphics IOMMU is enabled.
> > > Running Xen with iommu=no-igfx is similar to running Linux with
> > > intel_iommu=igfx_off, which disables IOMMU for Intel GPU. This can be
> > > used by users to manually workaround the problem before a fix is
> > > available for i915 driver.
> > > 
> > > Signed-off-by: Ting-Wei Lan <lantw44@gmail.com>
> > > Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
> > > Release-acked-by: Wei Liu <wei.liu2@citrix.com>
> > 
> > Acked-by: Kevin Tian <kevin.tian@intel.com>
> 
> Thanks for the quick turnaround!

Applied.