From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Jan Beulich" Subject: Re: pre Sandy bridge IOMMU support (gm45) Date: Mon, 25 Jan 2016 07:30:29 -0700 Message-ID: <56A63F9502000078000CAAD1@prv-mh.provo.novell.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Disposition: inline List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Thierry Laurion Cc: xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org >>> On 23.01.16 at 08:38, wrote: > Thinkpad x200 p8600 laptops have vt-d, vt-x and tpm. They also have intel > integrated graphics 4 Series (gm45 chipset), supported through i915 driver. > > In December, a fix got introduced to Xen 4.6 through iommu=no-igfx switch. > Before that fix, it was impossible to boot xen without passing iommu=0. > > With iommu=no-igfx passed on, Qubes boots xen, kernel, dom0 and domu until > some graphic rendering is done from a domu to dom0 xserver. > > I'm trying to push forward IOMMU support of gm45 chipset here. The problem > is between i915 and xen iommu support for sure, but there is no crash or > interesting debugging information given on a serial console. To be honest, even after having read you second mail I'm not quite clear what it you want and/or what doesn't work. Adding some guessing, I could interpret the above as you wanting to pass through the graphics device. If that's the case, then this is quite clearly a pretty bad idea with the IOMMU behind it disabled. Jan