From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Tian, Kevin" Subject: Re: [PATCH v4] VT-d: add iommu=igfx option to workaround graphics issues Date: Thu, 6 Aug 2015 00:49:51 +0000 Message-ID: References: <20150805133524.GN26074@zion.uk.xensource.com> <1438794606-6891-1-git-send-email-lantw44@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1438794606-6891-1-git-send-email-lantw44@gmail.com> Content-Language: en-US List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Ting-Wei Lan , "xen-devel@lists.xen.org" Cc: "Zhang, Yang Z" , Julien Grall , Wei Liu , Jan Beulich , Andrew Cooper List-Id: xen-devel@lists.xenproject.org > 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 > Reviewed-by: Andrew Cooper > Release-acked-by: Wei Liu Acked-by: Kevin Tian