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      <base href="https://bugs.freedesktop.org/">
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    <body><table border="1" cellspacing="0" cellpadding="8">
        <tr>
          <th>Bug ID</th>
          <td><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW - [KVM][GVT-d] [BDW & SKL ]Ubuntu 16.04 guest boot up with kernel panic with the newest 4.9.0-rc4+ drm-intel kernel"
   href="https://bugs.freedesktop.org/show_bug.cgi?id=99025">99025</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>[KVM][GVT-d] [BDW & SKL ]Ubuntu 16.04 guest boot up with kernel panic with the newest 4.9.0-rc4+ drm-intel kernel
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>DRI
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>DRI git
          </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>terrence.xu@intel.com
          </td>
        </tr>

        <tr>
          <th>QA Contact</th>
          <td>intel-gfx-bugs@lists.freedesktop.org
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>gordon.jin@intel.com, intel-gfx-bugs@lists.freedesktop.org, jani.saarinen@intel.com, zhiyuan.lv@intel.com
          </td>
        </tr>

        <tr>
          <th>i915 platform</th>
          <td>BDW, SKL
          </td>
        </tr></table>
      <p>
        <div>
        <pre>System Environment
=======
Host kernel repo: kvm.git
Host commit: master-813ae37e
Guest repo: drm-intel.git
Guest commit: drm-intel-next-queued-312c3c46

Regression?
=======
Yes

Bug detailed description
=======
The guest boot up with the latest drm-intel 4.9.0-rc4+ kernel with kernel
panic, but can boot up with the drm-intel 4.8.0-rc2+.
This is KVM GVT-d environment issue.

Reproduce Steps
==============
Boot up Ubuntu 16.04 guest with the drm-intel kernel, the command as below:
qemu-system-x86_64 --enable-kvm -m 2048 -smp 4 -hda /root/ubuntu-16.04.img -usb
-usbdevice tablet -device virtio-net-pci,netdev=nic0,mac=00:16:3e:60:0a:50
-netdev tap,id=nic0,script=/etc/kvm/qemu-ifup -serial stdio

Expected Result
=============
Guest boot up successfully.

Actual Result
===========
Guest boot up with kernel panic.

Analysis & Root Cause
===================
Ubuntu 16.04.1 LTS gvt-ub16 ttyS0

gvt-ub16 login: root
Password:
Last login: 一 2月  6 18:11:05 CST 2017 from 192.168.101.32 on pts/4
Welcome to Ubuntu 16.04.1 LTS (GNU/Linux 4.9.0-rc4+ x86_64)

 * Documentation:  <a href="https://help.ubuntu.com">https://help.ubuntu.com</a>
 * Management:     <a href="https://landscape.canonical.com">https://landscape.canonical.com</a>
 * Support:        <a href="https://ubuntu.com/advantage">https://ubuntu.com/advantage</a>

219 packages can be updated.
0 updates are security updates.

[   15.559269] general protection fault: 0000 [#1] SMP
[   15.560254] Modules linked in: fuse serio_raw sg acpi_cpufreq i2c_piix4
i2c_core parport_pc ppdev lp parport ext4 jbd2 mbcache sr_mod sd_mod cdrom
ata_generic pata_acpi virtio_net virtio_pci ata_piix virtio_ring libata virtio
floppy
[   15.565042] CPU: 3 PID: 1449 Comm: systemd-logind Not tainted 4.9.0-rc4+ #6
[   15.566244] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.10.0-0-gd7adf60-prebuilt.qemu-project.org 04/01/2014
[   15.568460] task: ffff8800288667c0 task.stack: ffffc90000e84000
[   15.569561] RIP: 0010:[<ffffffff81204bdb>]  [<ffffffff81204bdb>]
__kmalloc_track_caller+0xbb/0x200
[   15.571234] RSP: 0018:ffffc90000e87da8  EFLAGS: 00010286
[   15.572217] RAX: 0000000000000000 RBX: 00000000024000c0 RCX:
0000000000000fd2
[   15.573537] RDX: 0000000000000fd1 RSI: 0000000000000000 RDI:
000000000001c6e0
[   15.574840] RBP: ffffc90000e87de0 R08: ffff88007fd9c6e0 R09:
ffff88007d003cc0
[   15.576171] R10: ffff007366706d74 R11: ffff88007985e9f8 R12:
00000000024000c0
[   15.577476] R13: 0000000000000006 R14: ffffffff811bbe63 R15:
ffff88007d003cc0
[   15.578926] FS:  00007f12aa0db8c0(0000) GS:ffff88007fd80000(0000)
knlGS:0000000000000000
[   15.580474] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   15.581510] CR2: 00007f12aa0f8000 CR3: 000000007badf000 CR4:
00000000000006e0
[   15.582497] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
[   15.583305] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:
0000000000000400
[   15.584844] Stack:
[   15.585276]  ffff880066f1d00c ffffffff82232718 ffff88007cb86a80
0000000000000006
[   15.586537]  00000000024000c0 ffff88007cb86a80 0000000000000000
ffffc90000e87e08
[   15.587500]  ffffffff811bbe11 ffff880066f1cf00 ffffffff822326bc
ffff880066f1d00c
[   15.588455] Call Trace:
[   15.588760]  [<ffffffff811bbe11>] kstrdup+0x31/0x60
[   15.589362]  [<ffffffff811bbe63>] kstrdup_const+0x23/0x30
[   15.590028]  [<ffffffff81249500>] alloc_vfsmnt+0xb0/0x220
[   15.590669]  [<ffffffff812496a6>] vfs_kern_mount+0x36/0x110
[   15.591357]  [<ffffffff8124bf09>] do_mount+0x1e9/0xd10
[   15.591944]  [<ffffffff8124cd65>] SyS_mount+0x95/0xe0
[   15.592478]  [<ffffffff816ed3b7>] entry_SYSCALL_64_fastpath+0x1a/0xa9
[   15.593242] Code: 08 65 4c 03 05 77 55 e0 7e 49 83 78 10 00 4d 8b 10 0f 84
ce 00 00 00 4d 85 d2 0f 84 c5 00 00 00 49 63 41 20 48 8d 4a 01 49 8b 39 <49> 8b
1c 02 4c 89 d0 65 48 0f c7 0f 0f 94 c0 84 c0 74 bb 49 63
[   15.596546] RIP  [<ffffffff81204bdb>] __kmalloc_track_caller+0xbb/0x200
[   15.597374]  RSP <ffffc90000e87da8>
[   15.597820] ---[ end trace 83cb5720d8dea4cd ]---
[   15.598404] Kernel panic - not syncing: Fatal exception
[   15.599176] Kernel Offset: disabled</pre>
        </div>
      </p>


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