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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 - [HSW/BDW] i915 driver in kernels prior to 4.2 fail in KVM virtual machines with Intel IGD passthrough"
href="https://bugs.freedesktop.org/show_bug.cgi?id=92906">92906</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>[HSW/BDW] i915 driver in kernels prior to 4.2 fail in KVM virtual machines with Intel IGD passthrough
</td>
</tr>
<tr>
<th>Product</th>
<td>DRI
</td>
</tr>
<tr>
<th>Version</th>
<td>XOrg 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>david.j.cowperthwaite@intel.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></table>
<p>
<div>
<pre>On 4.2 kernel there's a failure in intel_uncore.c but the kernel load
progresses and the VM boots, DRI / Mesa / MSDK all work.
On kernels prior to this, (4.1 and earlier were tested) the VM stops @ the
point where drm reports that it is "Replacing the VGA console driver" and no
crash is output.
This output is from a HSW Corei7 with Iris Pro graphics (Gigabyte Brix Pro).
The Host OS is Centos7.1 with KVM installed and the patch to reject passthrough
of devices with RMRR tables (<a href="https://lkml.org/lkml/2014/7/3/580">https://lkml.org/lkml/2014/7/3/580</a>) reversed.
The Virtual Machine is also Centos7.1, the goal is to have Intel Media SDK
(requires 3.10 kernel + MSDK specific patchset) working in a VM on KVM on HSW &
BDW (later SKL). Host PCI device 0:2.0 (IGD) is mapped through to the VM.
Call Trace form the 4.2 kernel (which did eventually work)
[ 8.361933] [drm] Found 128MB of eLLC
[ 8.364588] [drm] Memory usable by graphics device = 2048M
[ 8.364675] [drm] Replacing VGA console driver
[ 8.369307] systemd[1]: Received SIGCHLD from PID 490 (lvm).
[ 8.369703] ------------[ cut here ]------------
[ 8.369730] WARNING: CPU: 1 PID: 526 at
drivers/gpu/drm/i915/intel_uncore.c:620
hsw_unclaimed_reg_debug.isra.14+0x78/0xa0 [i915]()
[ 8.369731] Unclaimed register detected after writing to register 0x6120c
[ 8.369752] Modules linked in: snd_hda_intel(+) snd_hda_codec snd_hda_core
snd_hwdep snd_seq snd_seq_device snd_pcm ppdev joydev snd_timer i915(+) snd
input_leds video serio_raw soundcore i2c_algo_bit pcspkr virtio_balloon
i2c_piix4 parport_pc 8250_fintek parport acpi_cpufreq uinput xfs libcrc32c
virtio_blk sr_mod cdrom virtio_console virtio_net ata_generic pata_acpi qxl
syscopyarea ata_piix sysfillrect sysimgblt drm_kms_helper ttm virtio_pci
virtio_ring virtio drm libata floppy dm_mirror dm_region_hash dm_log dm_mod
[ 8.369754] CPU: 1 PID: 526 Comm: systemd-udevd Not tainted
4.2.0-1.el7.elrepo.x86_64 #1
[ 8.369755] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
[ 8.369757] 0000000000000000 000000008918e0ce ffff880079543708
ffffffff816aebe9
[ 8.369758] 0000000000000000 ffff880079543760 ffff880079543748
ffffffff810798ea
[ 8.369760] 00003ffffffff000 ffff88007ac40078 000000000006120c
ffff88007ac40078
[ 8.369760] Call Trace:
[ 8.369765] [<ffffffff816aebe9>] dump_stack+0x45/0x57
[ 8.369767] [<ffffffff810798ea>] warn_slowpath_common+0x8a/0xc0
[ 8.369768] [<ffffffff81079975>] warn_slowpath_fmt+0x55/0x70
[ 8.369772] [<ffffffff810c1581>] ?
__raw_callee_save___pv_queued_spin_unlock+0x11/0x20
[ 8.369775] [<ffffffff810662b4>] ? iounmap+0x84/0xb0
[ 8.369791] [<ffffffffa034ecc8>] hsw_unclaimed_reg_debug.isra.14+0x78/0xa0
[i915]
[ 8.369804] [<ffffffffa03504e3>] hsw_write32+0x93/0x130 [i915]
[ 8.369819] [<ffffffffa0359b41>] intel_setup_bios+0x81/0x90 [i915]
[ 8.369840] [<ffffffffa03abd80>] i915_driver_load+0x520/0xed0 [i915]
[ 8.369843] [<ffffffff81568770>] ? trace_open+0x30/0x30
[ 8.369846] [<ffffffff81318880>] ? cleanup_uevent_env+0x10/0x10
[ 8.369847] [<ffffffff81318c0f>] ? kobject_uevent_env+0x15f/0x660
[ 8.369851] [<ffffffff8145385f>] ? devtmpfs_create_node+0x10f/0x140
[ 8.369853] [<ffffffff810c1581>] ?
__raw_callee_save___pv_queued_spin_unlock+0x11/0x20
[ 8.369856] [<ffffffff8169f29c>] ? klist_add_tail+0x3c/0x50
[ 8.369859] [<ffffffff81449af0>] ? device_add+0x270/0x600
[ 8.369861] [<ffffffff810c1581>] ?
__raw_callee_save___pv_queued_spin_unlock+0x11/0x20
[ 8.369871] [<ffffffffa00b61bf>] drm_dev_register+0xaf/0x100 [drm]
[ 8.369878] [<ffffffffa00b8ebf>] drm_get_pci_dev+0x8f/0x1e0 [drm]
[ 8.369891] [<ffffffffa02ff1fb>] i915_pci_probe+0x3b/0x60 [i915]
[ 8.369893] [<ffffffff813537b5>] local_pci_probe+0x45/0xa0
[ 8.369895] [<ffffffff81354964>] ? pci_match_device+0xf4/0x120
[ 8.369896] [<ffffffff81354ab9>] pci_device_probe+0xe9/0x130
[ 8.369899] [<ffffffff8144ce4f>] driver_probe_device+0x14f/0x420
[ 8.369900] [<ffffffff8144d1b0>] __driver_attach+0x90/0xa0
[ 8.369901] [<ffffffff8144d120>] ? driver_probe_device+0x420/0x420
[ 8.369903] [<ffffffff8144abec>] bus_for_each_dev+0x6c/0xc0
[ 8.369905] [<ffffffff81316e87>] ? ida_get_new_above+0x217/0x270
[ 8.369906] [<ffffffff8144c89e>] driver_attach+0x1e/0x20
[ 8.369907] [<ffffffff8144c3c0>] bus_add_driver+0x1d0/0x290
[ 8.369909] [<ffffffff8144dba0>] driver_register+0x60/0xe0
[ 8.369910] [<ffffffff8135313c>] __pci_register_driver+0x4c/0x50
[ 8.369917] [<ffffffffa00b90f0>] drm_pci_init+0xe0/0x110 [drm]
[ 8.369918] [<ffffffffa0411000>] ? 0xffffffffa0411000
[ 8.369931] [<ffffffffa04110a0>] i915_init+0xa0/0xa8 [i915]
[ 8.369933] [<ffffffff8100213d>] do_one_initcall+0xcd/0x1f0
[ 8.369935] [<ffffffff811b3c6e>] ? __vunmap+0xae/0xf0
[ 8.369937] [<ffffffff811cf49f>] ? kmem_cache_alloc_trace+0x17f/0x1f0
[ 8.369940] [<ffffffff816a9e8e>] ? do_init_module+0x28/0x1ea
[ 8.369941] [<ffffffff816a9ec7>] do_init_module+0x61/0x1ea
[ 8.369945] [<ffffffff810fd1bc>] load_module+0x1cfc/0x2600
[ 8.369946] [<ffffffff810f9870>] ? __symbol_put+0x60/0x60
[ 8.369948] [<ffffffff810f9bf6>] ? copy_module_from_fd.isra.54+0x116/0x170
[ 8.369950] [<ffffffff810fdcdf>] SyS_finit_module+0x9f/0xd0
[ 8.369953] [<ffffffff816b5b6e>] entry_SYSCALL_64_fastpath+0x12/0x71
[ 8.369954] ---[ end trace 5e5cacb01a9cf63a ]---</pre>
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