5.4 Kernel troubles

[shag00]

I installed kernel 5.4 and found it didn't work, after selecting Ubuntu from the grub menu I get these messages:
1/ couldn't get size: 0x80000000000e and
2/ kvm: disabled by bios (repeatedly)

Running 19.10
Ryzen 3700X and X570 MB, a few of whose problems were supposed to be fixed in 5.4.

As far as I am aware only Intel have virtualization technology which is what I think the kvm messages refer to so I am at a bit of a loss.

[claydoh]

I am guessing it is a Mainline 'vanilla' kernel?
These have zero modifications that distros use to make them work fully, so things like this are normal.
There may be new support in 5.4, but if it is not built specifically with that enabled, or needs other things , it won't necessarily work with everything.
The messages you see on the screen likely have nothing to do with with any problems you have

[TWPonKubuntu]

I'm also running kernel 5.4, under Kubuntu 19.04 straight from the standard repositories, and do see the kvm (Kernel-based Virtual Machine) message, four times, on bootup. I'm not seeing any problems with the kernel itself and am happy with version 5.4. My understanding is the kvm is related to Intel processor space and I'm not using any virtual systems.

When you say 'it didn't work', what specifically failed? I've been using 5.4 since it was released and have no obvious problems.

[Radcliff]

Kernel 5.4

Works fine here on our Ryzen 2700U motherboard.

We're also getting the KVM message at boot (5 times, according to Kernel log in KSystemlog). This is not a bug.

12/26/19 6:33 PM	kvm	disabled by bios

Enabling AMD Virtualization in the BIOS removes the message in favor of this:

12/26/19 6:42 PM	kvm	Nested Virtualization enabled
12/26/19 6:42 PM	kvm	Nested Paging enabled

lsb_release -a && uname -r
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu Focal Fossa (development branch)
Release:        20.04
Codename:       focal
5.5.0-050500rc3-generic

Kernel 5.4 is in the pre-release channel here (Proposed):

ls /lib/modules
5.4.0-9-generic  5.5.0-050500rc3-generic

[shag00]

To clarify, "it didn't work", I mean the system prints out the 2 messages I listed above and just hangs, about 10 lines in total. I was using the mainline release,
5.4.0-050400-generic_5.4.0-050400.201911242031_amd64.deb

So it appears the kvm messages may not be such an issue and that the couldn't get size issue is the one, which has a long linux history and possibly relates to the GPU driver. Nvidia has released 4.40 but only 4.35 is in the repos.

[TWPonKubuntu]

When you say that your system "just hangs", please watch your disk activity light and note whether there is activity. My system does continue to run after the kvm messages and I do see disk activity leading to a normal boot up.

[shag00]

Lol, I can see that I need to brush up my communication skills. Yes, there is disk activity and I can Alt-F2 into a prompt. However, if I do nothing a black screen with the printed messages just stays on the screen, for up to 20 minutes until I reset. Further, when I press the reset button the Kubuntu flash screen pops up for a second.

[TWPonKubuntu]

Ok thanks, but I'm out of ideas here. Perhaps someone else can diagnose further?

[shag00]

I just tried 5.4.6 and tried to launch plasma (after alt-f2) but I get the message that it is missing a dependency to launch. Among other things it suggested I might install Wayland which further indicates it may be a Nvidia issue.