Arch Linux

Kosmonavt

Member

Registered: 2010-02-15

Posts: 100

[Solved] Random VirtualBox incompatibility with kernel26-ck

Hi folks

I have just built kernel26-ck (2.6.36) with BFS scheduler and 1000 Hz tick frequency. Apart from that, I have enabled processor type optimization and deselected some rare devices like Apple ones and 10Gbit network. System is working fine and very fast.

But I'm experiencing strange problems with latest VirtualBox (binary version). Its module compiles and modprobes fine, also virtual machines start without errors. After VM starts random (usually after 1-2 minutes) hard reboots occur. everything.log doesn't contain relevant information, also Xorg.0.log, errors.log, daemon.log say nothing.

I assume that the reason is kernel. But AFAIK VirtualBox feels much better with tick frequencies >=1000 Hz. Is this frequency too low? Which other options may interfere?

Last edited by Kosmonavt (2010-11-13 18:33:45)

kheophex

Member

Registered: 2009-12-07

Posts: 16

Re: [Solved] Random VirtualBox incompatibility with kernel26-ck

I have a similar problem. I just installed kernel26-ck from AUR yesterday and when, with VirtualBox 3.2.10 (starting a Win 7 machine) I get a hard reboot or if I'm lucky a guru meditation error. I've tried this with both PUEL and OSE editions and it doesn't make a difference. The modules do compile without issues. I've also tried disabling 2d/3d acceleration and nested paging but to no avail.

It does work under the vanilla kernel, though it could be something unrelated to ck as the version from AUR is 2.6.36 whereas the vanilla is 2.6.35.7-1 , so it could just be that.

nolochemical

Member

From: St. catharines, Ontario,Canada

Registered: 2009-05-25

Posts: 18

Website

Re: [Solved] Random VirtualBox incompatibility with kernel26-ck

--Using Vbox from arch repo, the aur verision was missing vboxmm.so module or something..

--vbox requires timer to be divisble by 1000

-- also using ck kernel 2.6.35.7-11

Only issue is although nested paging is enables/checked cofirming via mouse over 'v' icon says its diabled. Otherwise running right as rain. Tip: use sata hdd controller in vbox settings and get intel sata drivers (xp pro) for snappier disk i/o.

Last edited by nolochemical (2010-10-27 22:19:17)

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kheophex

Member

Registered: 2009-12-07

Posts: 16

Re: [Solved] Random VirtualBox incompatibility with kernel26-ck

About the timer, do you mean the HZ option in the config. Mine is set at 1000 Hz as well. The modules do load without error. I'm now using the virtualbox-ose from the repositories but it doesn't fix the issue.

kheophex

Member

Registered: 2009-12-07

Posts: 16

Re: [Solved] Random VirtualBox incompatibility with kernel26-ck

I've tried the following:

SInce CK alters the scheduler I thought that matching the number of virtual CPUs in the machine's setting to the number actual cores in my machine. This machines is a Dell Latituted E5400 which has a dual core CPU, so I've set the number of virtual cpus to 2 (was one before). To enable that, I had to go into the BIOS and enable the Virtualization support (funny that it worked before). After doing that, I've now been able to have the virtual machine running for 15 minutes now without issue (it does feel snappier under ck ).

My theory is that there's some corner case with the combination of the BFS scheduler, virtual box 3.2.10 and the number of Virtual CPUs and actual cores being different. Or maybe there's some change with virtualization in the new kernel where it tries to use some features of hardware virtualization that before it didn't try to do and since it was inactive whatever nasty looking number was returned to the piece of code responsible for doing that really confused the kernel. I really don't know which, but this is something that I really don't want to test as each failed test entails an unclean unmount of the filesystems .

Last edited by kheophex (2010-10-28 06:29:50)

Kosmonavt

Member

Registered: 2010-02-15

Posts: 100

Re: [Solved] Random VirtualBox incompatibility with kernel26-ck

Sorry for delay - I had too much work to write here.

First, looks like it's an issue of kernel 2.6.36, not 35.x. I tried recompiling the kernel with different settings. Using tick frequency 300 or 1000 Hz doesn't matter anything here. Also including/excluding BFQ disk scheduler. I activated hardware virtualization in BIOS. Yep, on stock 35.8 it allows giving 2 CPUs to VM, but under 2.6.36-ck it fails at start with error message. With 1 CPU as usual - hangs everything.

Kosmonavt

Member

Registered: 2010-02-15

Posts: 100

Re: [Solved] Random VirtualBox incompatibility with kernel26-ck

Just tested on kernel26-ck 2.6.36-9 with BFQ, tick frequency 1000 Hz and streamline option enabled. Tested VirtualBox - finally everything works so far - both with 1 and 2 CPUs enabled for VM. Looks like it was some regression in CK patchset. Marking as solved.