Description of problem:

An OOPs occurs during reboot.   Zbigniew  suggests that it nay be a bug in the QXL subsystem, and unrelated to the other problems we were investigationg;

Ref:  https://bugzilla.redhat.com/show_bug.cgi?id=1463745


Jun 26 10:51:00 bld-fedora27 kernel: ------------[ cut here ]------------
Jun 26 10:51:00 bld-fedora27 kernel: kernel BUG at drivers/gpu/drm/ttm/ttm_bo_util.c:589!
Jun 26 10:51:00 bld-fedora27 kernel: invalid opcode: 0000 [#1] SMP
Jun 26 10:51:00 bld-fedora27 kernel: Modules linked in: sunrpc crct10dif_pclmul crc32_pclmul ghash_clmulni_intel ppdev snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_seq
Jun 26 10:51:00 bld-fedora27 kernel: CPU: 1 PID: 339 Comm: plymouthd Not tainted 4.12.0-0.rc6.git3.1.fc27.x86_64 #1
Jun 26 10:51:00 bld-fedora27 kernel: Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
Jun 26 10:51:00 bld-fedora27 kernel: task: ffff91dd77990000 task.stack: ffffb69e00720000
Jun 26 10:51:00 bld-fedora27 kernel: RIP: 0010:ttm_bo_kmap+0x1af/0x250 [ttm]
Jun 26 10:51:00 bld-fedora27 kernel: RSP: 0018:ffffb69e00723ba8 EFLAGS: 00010206
Jun 26 10:51:00 bld-fedora27 kernel: RAX: ffff91dd77987b50 RBX: ffff91dd779dc858 RCX: ffff91dd779dcc08
Jun 26 10:51:00 bld-fedora27 kernel: RDX: 0000000000000300 RSI: 0000000000000000 RDI: ffff91dd77430d90
Jun 26 10:51:00 bld-fedora27 kernel: RBP: ffffb69e00723be0 R08: 0000000000010004 R09: ffff91dd779dc928
Jun 26 10:51:00 bld-fedora27 kernel: R10: 0000000000000008 R11: 0000000000000000 R12: ffffb69e00723c48
Jun 26 10:51:00 bld-fedora27 kernel: R13: 0000000000000000 R14: ffff91dd77430d70 R15: 0000000000000000
Jun 26 10:51:00 bld-fedora27 kernel: FS:  00007fa4e051fd00(0000) GS:ffff91dd7d400000(0000) knlGS:0000000000000000
Jun 26 10:51:00 bld-fedora27 kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Jun 26 10:51:00 bld-fedora27 kernel: CR2: 00005616290356f8 CR3: 0000000035b8b000 CR4: 00000000001406e0
Jun 26 10:51:00 bld-fedora27 kernel: Call Trace:
Jun 26 10:51:00 bld-fedora27 kernel:  qxl_bo_kmap+0x42/0x70 [qxl]
Jun 26 10:51:00 bld-fedora27 kernel:  qxl_draw_dirty_fb+0x1f5/0x420 [qxl]
Jun 26 10:51:00 bld-fedora27 kernel:  qxl_framebuffer_surface_dirty+0xa0/0xf0 [qxl]
Jun 26 10:51:00 bld-fedora27 kernel:  drm_mode_dirtyfb_ioctl+0x190/0x1d0 [drm]
Jun 26 10:51:00 bld-fedora27 kernel:  drm_ioctl+0x232/0x500 [drm]
Jun 26 10:51:00 bld-fedora27 kernel:  ? drm_mode_getfb+0x110/0x110 [drm]
Jun 26 10:51:00 bld-fedora27 kernel:  ? __might_sleep+0x4a/0x80
Jun 26 10:51:00 bld-fedora27 kernel:  ? selinux_file_ioctl+0x124/0x1e0
Jun 26 10:51:00 bld-fedora27 kernel:  do_vfs_ioctl+0xa6/0x720
Jun 26 10:51:00 bld-fedora27 kernel:  ? getnstimeofday64+0xe/0x20
Jun 26 10:51:00 bld-fedora27 kernel:  ? security_file_ioctl+0x43/0x60
Jun 26 10:51:00 bld-fedora27 kernel:  SyS_ioctl+0x79/0x90
Jun 26 10:51:00 bld-fedora27 kernel:  do_syscall_64+0x6c/0x1c0
Jun 26 10:51:00 bld-fedora27 kernel:  entry_SYSCALL64_slow_path+0x25/0x25
Jun 26 10:51:00 bld-fedora27 kernel: RIP: 0033:0x7fa4df504eb7
Jun 26 10:51:00 bld-fedora27 kernel: RSP: 002b:00007ffca83efbc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
Jun 26 10:51:00 bld-fedora27 kernel: RAX: ffffffffffffffda RBX: 0000000000001000 RCX: 00007fa4df504eb7
Jun 26 10:51:00 bld-fedora27 kernel: RDX: 00007ffca83efc00 RSI: 00000000c01864b1 RDI: 0000000000000009
Jun 26 10:51:00 bld-fedora27 kernel: RBP: 00007ffca83efc00 R08: 00007fa4dd42577c R09: 0000000000000010
Jun 26 10:51:00 bld-fedora27 kernel: R10: 00007fa4dd424884 R11: 0000000000000246 R12: 00000000c01864b1
Jun 26 10:51:00 bld-fedora27 kernel: R13: 0000000000000009 R14: 0000555e394ef330 R15: 00007fa4ddf8278c
Jun 26 10:51:00 bld-fedora27 kernel: Code: d0 48 8b bb 80 00 00 00 48 c1 e6 0c f6 43 62 04 74 44 48 03 7b 70 4c 01 ef e8 8e 21 bd ef 49 89 04 24 44 8b 45 d0 e9 18 ff ff ff <0f> 0b 4b 8d 7c 3e 58 89 4
Jun 26 10:51:00 bld-fedora27 kernel: RIP: ttm_bo_kmap+0x1af/0x250 [ttm] RSP: ffffb69e00723ba8
Jun 26 10:51:00 bld-fedora27 kernel: ---[ end trace 13b661e538049e06 ]---

Version-Release number of selected component (if applicable):
xorg-x11-drv-qxl-0.1.5-3.fc26.x86_64


How reproducible:


Steps to Reproduce:
1. reboot
2.
3.

Actual results:


Expected results:


Additional info:

https://bugzilla.redhat.com/show_bug.cgi?id=1463745