Hi Dave,
On kernel versions 4.20 and greater, the MGA G200 driver has a fatal error during GPU init and the KVM console I use hangs. I still can ssh into the machine, however. The log and some basic info is below. This error is 100% reproducible for me, on different machines. With kernel 4.19, I don't see any error and the KVM console works correctly. Please let me know if you need any more information. (Also, I wasn't sure which email to use, the DRM drivers maintainer email is the linux.ie one and the mgag200 maintainer email is the redhat.com one, so I sent it to both).
Thanks, Oliver
[ 2.297347] pstore: Unknown compression: deflate [ 2.297362] fbcon: Taking over console [ 2.297465] Console: switching to colour frame buffer device 128x48 [snip] [ 3.053910] fb0: switching to mgag200drmfb from simple [ 3.053946] Console: switching to colour dummy device 80x25 [ 3.054377] [drm:mgag200_driver_load [mgag200]] *ERROR* can't reserve VRAM [ 3.054383] mgag200 0000:03:00.0: Fatal error during GPU init: -6
# lspci | grep -i vga
03:00.0 VGA compatible controller: Matrox Electronics Systems Ltd. MGA G200e [Pilot] ServerEngines (SEP1) (rev 42)
# modinfo mgag200
filename: /lib/modules/5.0.0-rc7-next-20190220+/kernel/drivers/gpu/drm/mgag200/mgag200.ko license: GPL description: MGA G200 SE author: Matthew Garrett srcversion: B5EC0E424CE53736E84252D alias: pci:v0000102Bd00000538sv*sd*bc*sc*i* alias: pci:v0000102Bd00000536sv*sd*bc*sc*i* alias: pci:v0000102Bd00000534sv*sd*bc*sc*i* alias: pci:v0000102Bd00000533sv*sd*bc*sc*i* alias: pci:v0000102Bd00000532sv*sd*bc*sc*i* alias: pci:v0000102Bd00000530sv*sd*bc*sc*i* alias: pci:v0000102Bd00000524sv*sd*bc*sc*i* alias: pci:v0000102Bd00000522sv*sd*bc*sc*i* depends: drm,drm_kms_helper,ttm,i2c-algo-bit retpoline: Y intree: Y name: mgag200 vermagic: 5.0.0-rc7-next-20190220+ SMP mod_unload modversions parm: modeset:Disable/Enable modesetting (int)