Suspending or freezing a KVM guest triggers the following warning reliably on current mainline:
[56691.550343] printk: Suspending console(s) (use no_console_suspend to debug) [56691.578735] WARNING: CPU: 37 PID: 462 at drivers/gpu/drm/ttm/ttm_tt.c:51 ttm_tt_create+0xb6/0xe0 [ttm] [56692.795234] Modules linked in: snd_hda_codec_generic(E) qxl(E) drm_ttm_helper(E) ttm(E) snd_hda_intel(E) snd_intel_dspcfg(E) snd_hda_codec(E) drm_kms_helper(E) snd_hwdep(E) snd_hda_core(E) cec(E) snd_pcm(E) snd_timer(E) drm(E) joydev (E) snd(E) pcspkr(E) sg(E) evdev(E) virtio_balloon(E) serio_raw(E) virtio_console(E) soundcore(E) button(E) virtio_rng(E) rng_core(E) ip_tables(E) x_tables(E) autofs4(E) ext4(E) crc32c_generic(E) crc16(E) mbcache(E) jbd2(E) hid_generic(E) usbhid(E) hid(E) virtio_net(E) net_failover(E) failover(E) uhci_hcd(E) virtio_blk(E) sr_mod(E) cdrom(E) ata_generic(E) ehci_pci(E) ata_piix(E) ehci_hcd(E) libata(E) virtio_pci(E) usbcore(E) psmouse(E) virtio_ring(E) scsi_mod(E) i2c_piix4(E) virtio(E) floppy(E) [56691.578781] CPU: 37 PID: 462 Comm: kworker/37:1 Tainted: G E 5.8.0+ #8217 [56691.578784] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 [56692.795348] Workqueue: events drm_fb_helper_dirty_work [drm_kms_helper] [56691.578872] RIP: 0010:ttm_tt_create+0xb6/0xe0 [ttm] [56691.578903] Call Trace: [56691.578912] ttm_bo_kmap+0x13c/0x260 [ttm] [56691.578942] qxl_bo_kmap+0x40/0x70 [qxl] [56691.578947] qxl_gem_prime_vmap+0x21/0x50 [qxl] [56691.579060] drm_gem_vmap+0x1f/0x50 [drm] [56691.579073] drm_client_buffer_vmap+0x1c/0x30 [drm] [56691.579083] drm_fb_helper_dirty_work+0xb2/0x1c0 [drm_kms_helper] [56691.579091] process_one_work+0x246/0x580 [56691.579099] ? process_one_work+0x580/0x580 [56691.579101] worker_thread+0x30/0x370 [56691.579104] ? process_one_work+0x580/0x580 [56691.579107] kthread+0x12a/0x140 [56691.579110] ? kthread_park+0x80/0x80 [56691.579118] ret_from_fork+0x22/0x30
Have not had time to figure out whether this is a regression or an older issue. If you need further info please let me know.
Thanks,
tglx