From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: [PATCH v2] VT-d: add iommu=igfx option to workaround graphics issues Date: Sun, 26 Jul 2015 17:47:53 +0100 Message-ID: <55B50F39.3060108@citrix.com> References: <55ACD1940200007800092EF8@mail.emea.novell.com> <1437843452-12126-1-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: <1437843452-12126-1-git-send-email-lantw44@gmail.com> 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: Yang Zhang , Julien Grall , Kevin Tian , Jan Beulich List-Id: xen-devel@lists.xenproject.org On 25/07/2015 17:57, 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 option to control whether Intel graphics IOMMU is enabled on > these devices. Running Xen with iommu=no-igfx is similar to running > Linux with intel_iommu=igfx_off, which disables IOMMU for Intel Ironlake > 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