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<base href="https://bugs.freedesktop.org/" />
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Linux >= 3.19 graphics corruption and system crash when running as Xen dom0 with VT-d enabled on Intel Ironlake"
href="https://bugs.freedesktop.org/show_bug.cgi?id=91400">91400</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>Linux >= 3.19 graphics corruption and system crash when running as Xen dom0 with VT-d enabled on Intel Ironlake
</td>
</tr>
<tr>
<th>Product</th>
<td>DRI
</td>
</tr>
<tr>
<th>Version</th>
<td>unspecified
</td>
</tr>
<tr>
<th>Hardware</th>
<td>x86-64 (AMD64)
</td>
</tr>
<tr>
<th>OS</th>
<td>Linux (All)
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>major
</td>
</tr>
<tr>
<th>Priority</th>
<td>medium
</td>
</tr>
<tr>
<th>Component</th>
<td>DRM/Intel
</td>
</tr>
<tr>
<th>Assignee</th>
<td>intel-gfx-bugs@lists.freedesktop.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>lantw44@gmail.com
</td>
</tr>
<tr>
<th>QA Contact</th>
<td>intel-gfx-bugs@lists.freedesktop.org
</td>
</tr>
<tr>
<th>CC</th>
<td>intel-gfx-bugs@lists.freedesktop.org
</td>
</tr>
<tr>
<th>Depends on</th>
<td>90037
</td>
</tr></table>
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<pre>Created <span class=""><a href="attachment.cgi?id=117251" name="attach_117251" title="dmesg">attachment 117251</a> <a href="attachment.cgi?id=117251&action=edit" title="dmesg">[details]</a></span>
dmesg
+++ This bug was initially created as a clone of <a class="bz_bug_link
bz_status_REOPENED "
title="REOPENED - After upgrading to Linux 3.19, desktop no longer works in Xen 4.5.0 dom0"
href="show_bug.cgi?id=90037">Bug #90037</a> +++
When I use Linux >= 3.19 as the dom0 kernel of Xen, screen becomes unreadable
after i915 driver is loaded. The screenshot is already posted as an attachment
of another bug: <a href="https://bugs.freedesktop.org/attachment.cgi?id=115079">https://bugs.freedesktop.org/attachment.cgi?id=115079</a>. This
screenshot is obtained when the system is in single user mode.
If it continues to boot into graphical mode, a lot of error messages are showed
when the display manager is started. Screen output becomes more broken and the
system crashes after several minutes.
VT-d is automatically enabled by Xen. If VT-d is manually disabled, there is no
graphics problem and the system can run normally.
The bad commit showed by git bisect is
<a href="https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=47591df">https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=47591df</a>
Please see the attached Xen dmesg, Linux dmesg and GPU crash dump.
CPU and GPU:
Intel Core i5 CPU 650 @ 3.20GHz
Intel Ironlake Desktop
Motherboard:
ASUSTeK Computer INC. P7H55D-M EVO
Software:
Xen 4.5.1
Linux 4.2-rc3
Xorg 1.17.2
Wayland 1.7.0
GDM 3.16.2
GNOME Shell 3.16.3
This problem was initially reported as here:
<a class="bz_bug_link
bz_status_REOPENED "
title="REOPENED - After upgrading to Linux 3.19, desktop no longer works in Xen 4.5.0 dom0"
href="show_bug.cgi?id=90037">https://bugs.freedesktop.org/show_bug.cgi?id=90037</a>
I sent a message to xen-devel and they thought it should be an i915 problem:
<a href="http://lists.xenproject.org/archives/html/xen-devel/2015-06/msg02236.html">http://lists.xenproject.org/archives/html/xen-devel/2015-06/msg02236.html</a>
<a href="http://lists.xenproject.org/archives/html/xen-devel/2015-06/msg02387.html">http://lists.xenproject.org/archives/html/xen-devel/2015-06/msg02387.html</a>
As I don't know how to fix the problem, I made a workaround in Xen:
<a href="http://lists.xenproject.org/archives/html/xen-devel/2015-07/msg03641.html">http://lists.xenproject.org/archives/html/xen-devel/2015-07/msg03641.html</a>
They also said it is an i915 problem:
<a href="http://lists.xenproject.org/archives/html/xen-devel/2015-07/msg03642.html">http://lists.xenproject.org/archives/html/xen-devel/2015-07/msg03642.html</a>
<a href="http://lists.xenproject.org/archives/html/xen-devel/2015-07/msg03723.html">http://lists.xenproject.org/archives/html/xen-devel/2015-07/msg03723.html</a>
A silimar problem also happens on Linux >= 3.7 without using Xen:
<a class="bz_bug_link
bz_status_NEW "
title="NEW - Graphics problems with intel_iommu=on on Linux >= 3.7"
href="show_bug.cgi?id=91127">https://bugs.freedesktop.org/show_bug.cgi?id=91127</a>
It was partially fixed in Linux 4.2-rc2:
<a href="https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=8b572a4">https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=8b572a4</a>
It seems there are some common messages showed by Xen and Linux:
Messages showed by Xen with Linux 4.2-rc3 dom0:
(XEN) [VT-D]DMAR:[DMA Write] Request device [0000:00:02.0] fault addr
73fbff000, iommu reg = ffff82c000203000
(XEN) [VT-D]DMAR: reason 05 - PTE Write access is not set
Messages showed by Linux 4.2-rc2 when not using Xen:
DMAR: DMAR:[DMA Write] Request device [00:02.0] fault addr fde7c000
DMAR:[fault reason 05] PTE Write access is not set</pre>
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