Hi, we are running VM as guest on Windows (on Win 10, 11 Enterprise, as required by employer) and recently are facing laggy console output: often the console screen update takes quite some time, instead of a fraction of a second it takes one second, during which only a half (right side) get updated but the other half keeps the old content, which is bad when scrolling or using tmux/vim or such.
I compared it with a previous working version of the VM and I noticed that the kernel changed from 6.1.0-21-amd64 to 6.1.0-31-amd64, and there is one probably related change in dmesg. In the working case with old kernel I get: fbcon: svgadrmfb (fb0) is primary device but in the "laggy" case with the new kernel I get: fbcon: vmwgfxdrmfb (fb0) is primary device Since the old kernel is still available I could easily boot it (manual selecting in grub advanced), and doing so eliminates the problem. However, using an old kernel can be temporary only, so I'm looking for a solution. To my surprise, googling "svgadrmfb vmwgfxdrmfb" did not reveal anything useful helping me to understand the nature of the issue or to derive solutions; to my surprise, because I assume this should be a quite common setup and others should encounter the same, but apparently it is not the case. What do I do wrongly? Does anybody has any information on that topic, any hints, suggestions? Thank you for reading this long text, Steffen dmesg 6.0.3 vs 6.0.7 old: [ 0.000000] Linux version 6.1.0-21-amd64 (debian-ker...@lists.debian.org) (gcc-12 (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40) #1 SMP PREEMPT_DYNAMIC Debian 6.1.90-1 (2024-05-03) new: [ 0.000000] Linux version 6.1.0-31-amd64 (debian-ker...@lists.debian.org) (gcc-12 (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40) #1 SMP PREEMPT_DYNAMIC Debian 6.1.128-1 (2025-02-07) old: [xxxxxxxxxxxx] [drm:vmw_host_printf [vmwgfx]] *ERROR* Failed to send host log message. [xxxxxxxxxxxx] fbcon: svgadrmfb (fb0) is primary device [xxxxxxxxxxxx] Console: switching to colour frame buffer device 100x37 new: [xxxxxxxxxxxx] [drm:vmw_host_printf [vmwgfx]] *ERROR* Failed to send host log message. [xxxxxxxxxxxx] fbcon: vmwgfxdrmfb (fb0) is primary device [xxxxxxxxxxxx] Console: switching to colour frame buffer device 160x50 [xxxxxxxxxxxx] vmwgfx 0000:00:02.0: [drm] fb0: vmwgfxdrmfb frame buffer device [xxxxxxxxxxxx] [drm] Initialized vmwgfx 2.20.0 20211206 for 0000:00:02.0 on minor 0 NB: This is a Debian-derived distribution called Devuan, but should differ only by not having systemd, so I'm asking here in the hope for a greater reach.
