On another test, using vanilla Ubuntu mainline 5.14.14 on a guest VBOX VM runs ok for about half a day then crashes to black screen. This has happened 4x!
Replacing the vanilla Ubuntu mainline 5.14.14 with a custom build of 5.14.14 using point 1 above (see comment 43) has so far worked for 3 days and is still working.
Having that configuration is dangerous in production settings! I can't stress it enough! If you use Ubuntu Mainline kernels in production settings, then...
****DO NOT USE UBUNTU MAINLINE 5.14.X KERNELS.****
Use Ubuntu mainline 5.13.x or rebuild the 5.14.x kernels from kernel.org and disable "CONFIG_UBSAN_TRAP" in the kernel config.
On another test, using vanilla Ubuntu mainline 5.14.14 on a guest VBOX VM runs ok for about half a day then crashes to black screen. This has happened 4x!
Replacing the vanilla Ubuntu mainline 5.14.14 with a custom build of 5.14.14 using point 1 above (see comment 43) has so far worked for 3 days and is still working.
Having that configuration is dangerous in production settings! I can't stress it enough! If you use Ubuntu Mainline kernels in production settings, then...
****DO NOT USE UBUNTU MAINLINE 5.14.X KERNELS.****
Use Ubuntu mainline 5.13.x or rebuild the 5.14.x kernels from kernel.org and disable "CONFIG_UBSAN_TRAP" in the kernel config.