Massiv slowdown, Centos 7.4 Guest, Spectre-Patch

[Cymric]

Hello,
I have a new Elitebook 840 (i7-8550U), Windows 10 Host, Centos 7.4 Guest. All drivers/bios/Vbox (5.2.8) are on the latest version. Also virtualization etc is enabled and no hardening problems are found. But under Linux X/Window is a bit choppy and applications are reacting very slow, e.g running a python test suite is about 100% slower compared to a similar setup on an older HP ZBook. Or if I refresh in GitExtensions the tree it takes around 6s and 70% CPU usage compared to 1s on the Zbook. The Zbook has the same setup up and almost the same specs (Passmark) as the Elitebook (the disk access is even faster). Under Windows I have no performance problems.
I know you cannot compare a Workstation Laptop and an "Ultrabook", but I experienced the same 2 months ago with the ZBook, then HP released a Spectre Bios Update.
So I tried to look at the current status of the Spectre&Meltdown Patches. I started "InSpectre" and I'm protected against Spectre and Meltdown. I disabled the Spectre protection and all problems vanished. The Python test suite no takes 26s instead of 110s. This is not a slight performance loss.
I know that the Spectre patches have an impact on the performance, but who will fix this problem with virtualbox? Microsoft, HP, Intel, Centos or Virtualbox?
Regards,
Roland

[socratis]

I know that the Spectre patches have an impact on the performance, but who will fix this problem with virtualbox? Microsoft, HP, Intel, Centos or Virtualbox?

I'm not sure the 1st part of your sentence agrees with the 2nd part. If you know that there *is* going to be a performance hit, why do you expect anyone will be able to fix it? This is an "Oops" situation that you can't get out of.

It's your choice; performance or patches.

[HF]

I had exactly the same problem. It became more apparent after moving from VirtualBox 5 to 6. When I disable the Spectre mitigations on the host, my guest performance improves about 40%.

From reading other threads, this is not an issue when running VMs on MS hypervisor or VMWare.