Paravirtualisation Mode for Windows Guests on Linux Host [Solved]

Discussions related to using VirtualBox on Linux hosts.
Post Reply
yoloClin
Posts: 17
Joined: 31. May 2018, 03:02

Paravirtualisation Mode for Windows Guests on Linux Host [Solved]

Post by yoloClin »

I'm attempting to troubleshoot idle CPU performance around the 15-30% mark on Windows guest machines built with Packer. Iirc packer is frowned upon by the VirtualBox developers, I'm unclear on exactly why (Presumably this exact issue). I would really appreciate any known issues with Packer that so I could work around them.

I've suspect among other things, the paravirtualisation mode I've set is possibly incorrect. Under a W10 image I built directly with Virtualbox, the paravirtualisation mode is 'default' - I suspect this is Hyper-V Paravirtualisation based on documentation, but I'm unsure how to confirm. XML for the image says the selected mode is 'default' which is unhelpful. Documentation at https://www.virtualbox.org/manual/ch10. ... mproviders says it is 'recommended' but does not explicitly say default. Can anybody confirm?
Last edited by yoloClin on 12. May 2022, 23:22, edited 1 time in total.
fth0
Volunteer
Posts: 5668
Joined: 14. Feb 2019, 03:06
Primary OS: Mac OS X other
VBox Version: PUEL
Guest OSses: Linux, Windows 10, ...
Location: Germany

Re: Paravirtualisation Mode for Windows Guests on Linux Host

Post by fth0 »

yoloClin wrote:Under a W10 image I built directly with Virtualbox, the paravirtualisation mode is 'default' - I suspect this is Hyper-V Paravirtualisation based on documentation, but I'm unsure how to confirm.
VBox.log file wrote:
00:00:01.582911 [/GIM/] (level 1)
00:00:01.582911   Provider <string>  = "HyperV" (cb=7)
[...]
00:00:01.598878 GIM: Using provider 'HyperV' (Implementation version: 0)
00:00:01.598884 GIM: HyperV: Reporting vendor as 'VBoxVBoxVBox'
Check the VBox.log file for those lines, which will show the effective paravirtualization provider. My example is from a Windows 10 VM with System > Acceleration > Paravirtualization Interface set to Default.
mpack
Site Moderator
Posts: 39156
Joined: 4. Sep 2008, 17:09
Primary OS: MS Windows 10
VBox Version: PUEL
Guest OSses: Mostly XP

Re: Paravirtualisation Mode for Windows Guests on Linux Host [Solved]

Post by mpack »

yoloClin wrote:Under a W10 image I built directly with Virtualbox, the paravirtualisation mode is 'default' ... XML for the image says the selected mode is 'default' which is unhelpful.
As you said, that is how the option is configured, so what else do you expect to see in the config file? "Default" means that the choice is made at runtime, not by a settings file. The runtime decision can be found in the log, but of course it's very predictable: VMs using Windows templates get Hyper-v, those using Linux templates get KVM.
Post Reply