Fedora 20/21 VirtualBox hanging X11 on Broadwell

[crxssi]

I wanted to post about my problem to help any others with the same issue. We just got in some new Intel NUC computers with use the Broadwell Intel Core i7 5557U CPU. After installing Fedora 20 64bit on the machine and Virtualbox, when we started guest machines, it will completely lockup X11 within seconds of the guest starting.... every time. Didn't matter which type of guest. No capslock, no mouse, no keyboard, but one can ssh in and reboot the machine (Xorg becomes unkillable).

Many hours of trying different settings and options were futile. I then tried Fedora 21. Same problem. I then tried Fedora 22 beta and used Oracle's latest VirtualBox from their site. Same problem. So then I tried Arch and Ubuntu- neither one had any problem.

FINALLY found it from these somewhat obscure threads:

https://forums.virtualbox.org/viewto...fedora#p319885
https://www.virtualbox.org/ticket/13961

I would report a bug on Fedora's bugzilla, but I have never done that before so I am not sure exactly the correct way. Perhaps someone else will at some point. Although it seems to be up-stream, it is bound to cause a lot of people headaches with brand new Intel machines.
It is a Virtualbox issue related to Broadwell CPUs when the kernel has SMAP (Supervisor Mode Access Prevention). I assume that maybe Ubuntu and/or Arch don't have that on by default or something. The solution is to either use a patched VirtualBox driver (yeesh) or to disable smap by editing /etc/default/grub adding the “nosmap” option and installing it and booting with that option.

[stevea]

This is a VirtualBox problem, so you can't create a buzilla at the Redhat bugzilla cite. Fedora does not support VirtualBox. They will simply mark your bug report as invalid.



You should report this at the VirtualBox support cite (and I have no idea how).

It sounds like you have an easy fix with your grub nosmap config. Use it.

Actually the Linux kernel guys have a lot of problems w/ ppl reporting VBox driver bugs. They won't touch them either. The VBox driver is not supported w/in Linux, it's purely a VirtualBox issue.

[crxssi]

This is a VirtualBox problem, so you can't create a buzilla at the Redhat bugzilla site. Fedora does not support VirtualBox. They will simply mark your bug report as invalid.

Yeah, I figured as much.

You should report this at the VirtualBox support site (and I have no idea how).

It is already there, sorta. Doesn't specifically mention Fedora, though.

It sounds like you have an easy fix with your grub nosmap config. Use it.

Indeed. I am very happy it is working. I lose "smap" support, but I don't think I care

Actually the Linux kernel guys have a lot of problems w/ ppl reporting VBox driver bugs. They won't touch them either. The VBox driver is not supported w/in Linux, it's purely a VirtualBox issue.

True, but VirtualBox is a very important thing for many Linux users, so having it not work under Fedora, especially when it works fine under Ubuntu and Arch, is troubling. I just wanted to take the time to put it here so hopefully someone in the same boat we were in can find a solution without tearing their hair out like I did.

[stevea]

]
True, but VirtualBox is a very important thing for many Linux users, so having it not work under Fedora, especially when it works fine under Ubuntu and Arch, is troubling. I just wanted to take the time to put it here so hopefully someone in the same boat we were in can find a solution without tearing their hair out like I did.

Try using KVM. I prefer it, and it is well supported - buy the kernel and by Fedora/Redhat. If you VM is any Linux, consider Docker.

I strongly suspect that IF you try the same vbox driver against the same kernel you'll see the same result on all the distros. The main diff is that Ubuntu and maybe Arch allow non-free packages into some of their repos and they pick the right driver or patch it. . Fedora will never do that. You'll find some non-free stuff for Fedora at rpmfusion & such, but Fedora will never support it.


If you need official vbox support, then Fedora is not for you.

Neither is the Linux kernel ultimately, since the kernel developers don't support vbox.