I have live system (Guest: Debian 13 Trixie, kernel 6.12.107+deb13-amd64, Host: Proxmox VE 9.2.10) where this bug occurred - having virtual serial port with working SysRQ. Here is list of blocked tasks (w):
sysrq: Show Blocked State task:kworker/0:2 state:D stack:0 pid:55050 tgid:55050 ppid:2 flags:0x00004000 Workqueue: events drm_fb_helper_damage_work [drm_kms_helper] Call Trace: <TASK> __schedule+0x505/0xc00 schedule+0x27/0xc0 schedule_timeout+0x9e/0x160 ? __pfx_process_timeout+0x10/0x10 qxl_fence_wait+0xf6/0x190 [qxl] ? __pfx_autoremove_wake_function+0x10/0x10 dma_fence_wait_timeout+0x62/0x140 dma_resv_wait_timeout+0xc2/0x1d0 ttm_bo_wait_ctx+0x3d/0x60 [ttm] qxl_bo_move+0x4a/0xf0 [qxl] ttm_bo_handle_move_mem+0xb8/0x170 [ttm] ttm_bo_evict+0x119/0x170 [ttm] ? __vunmap_range_noflush+0x4d7/0x560 ttm_bo_evict_cb+0x77/0xd0 [ttm] ttm_lru_walk_for_evict+0x277/0x330 [ttm] ttm_bo_alloc_resource+0x146/0x3f0 [ttm] ttm_bo_validate+0x9f/0x180 [ttm] ttm_bo_init_reserved+0x146/0x170 [ttm] qxl_bo_create+0x152/0x210 [qxl] ? __pfx_qxl_ttm_bo_destroy+0x10/0x10 [qxl] qxl_alloc_bo_reserved+0x4b/0xb0 [qxl] qxl_image_alloc_objects+0xaf/0x130 [qxl] qxl_draw_dirty_fb+0x1ae/0x4f0 [qxl] qxl_framebuffer_surface_dirty+0x117/0x1e0 [qxl] drm_fbdev_ttm_helper_fb_dirty+0x216/0x310 [drm_ttm_helper] drm_fb_helper_damage_work+0x91/0x170 [drm_kms_helper] process_one_work+0x174/0x330 worker_thread+0x191/0x2f0 ? __pfx_worker_thread+0x10/0x10 kthread+0xcf/0x100 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x31/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> [TTM] Buffer eviction failed [TTM] Buffer eviction failed Plaese let me know if there is something more I can do on that hung guest for diagnostics.
