HVM troubleshooting
HVM pauses on boot, followed by kernel error
The HVM may pause on boot, showing a fixed cursor. After a while a series of warnings may be shown similar to this:
BUG: soft lockup - CPU#0 stuck for 23s! [systemd-udevd:244]
To fix this:
Kill the HVM.
Start the HVM
Press “e” at the grub screen to edit the boot parameters
Find the /vmlinuz line, and edit it to replace “rhgb” with “modprobe.blacklist=bochs_drm”
Press “Ctrl-x” to start the HVM
If this solves the problem then you will want to make the change permanent:
Edit the file
/etc/default/grub
.Find the line which starts:
GRUB_CMDLINE_LINUX=
Remove this text from that line:
rhgb
Add this text to that line:
modprobe.blacklist=bochs_drm
Run this command:
grub2-mkconfig --output=/boot/grub2/grub.cfg
The HVM should now start normally.
Can’t start an OS in an HVM / “Probing EDD (edd=off to disable!… ok” message
If you see a screen popup with SeaBios and 4 lines, last one being
Probing EDD (edd=off to disable!... ok
, then enter the following
command from a dom0
prompt:
qvm-prefs <HVMname> kernel ""
HVM crashes when booting from ISO
If your HVM crashes when trying to boot an ISO, first ensure that
qvm-prefs <HVMname> kernel
is empty, as shown above. If this doesn’t
help, then disable memory balancing and set the minimum memory to 2GB.
You can disable memory-balancing in the settings, under the “Advanced” tab.
To give the VM a RAM of 2GB, open a terminal in dom0
and enter:
qvm-prefs <HVMname> memory 2000
Attached devices in Windows HVM stop working on suspend/resume
After the whole system gets suspended into S3 sleep and subsequently resumed, some attached devices may stop working. To know how to make the devices work, see Suspend/resume Troubleshooting.