High host CPU load and slower guest after upgrade guest OS Windows 10 to ver 1803

Bug #1775702 reported by Giovanni Panozzo on 2018-06-07
108
This bug affects 20 people
Affects Status Importance Assigned to Milestone
QEMU
Undecided
Unassigned

Bug Description

After upgrading Windows 10 guest to version 1803, guests VM runs slower and there is high host CPU load even when guest is almost idle. Did not happened with windows 10 up to version 1709.

See my 1st report here:
https://askubuntu.com/questions/1033985/kvm-high-host-cpu-load-after-upgrading-vm-to-windows-10-1803

Another user report is here:
https://lime-technology.com/forums/topic/71479-windows-10-vm-cpu-usage/

Tested on: Ubuntu 16.04 with qemu 2.5.0 and i3-3217U, Arch with qemu 2.12 i5-7200U, Ubuntu 18.04 qemu 2.11.1 AMD FX-4300. All three platform showing the same slowdown and higher host cpu load with windows 10 1803 VM compared to windows 10 1709 VM.

Lemos Lemosov (lemosov) wrote :

This bug affect me

Heiko Sieger (h-sieger) wrote :

I ran into similar issues with Windows 10 (1803), with regard to 2D graphics performance.

See my bug report here: https://bugzilla.kernel.org/show_bug.cgi?id=200877

Could you test with Spectre protection (temporarily) turned off inside the Windows VM?

See my post here: https://heiko-sieger.info/low-2d-graphics-benchmark-with-windows-10-1803-kvm-vm/

Hi,
proxmox users have reported this bug
https://forum.proxmox.com/threads/high-cpu-load-for-windows-10-guests-when-idle.44531/#post-213876

hv_synic && hv_stimer hyperv enlightments fix it

(seem to be related to some hpet change in windows)

----- Mail original -----
De: "Lemos Lemosov" <email address hidden>
À: "qemu-devel" <email address hidden>
Envoyé: Mercredi 1 Août 2018 08:43:46
Objet: [Qemu-devel] [Bug 1775702] Re: High host CPU load and slower guest after upgrade guest OS Windows 10 to ver 1803

This bug affect me

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https://bugs.launchpad.net/bugs/1775702

Title:
High host CPU load and slower guest after upgrade guest OS Windows 10
to ver 1803

Status in QEMU:
New

Bug description:
After upgrading Windows 10 guest to version 1803, guests VM runs
slower and there is high host CPU load even when guest is almost idle.
Did not happened with windows 10 up to version 1709.

See my 1st report here:
https://askubuntu.com/questions/1033985/kvm-high-host-cpu-load-after-upgrading-vm-to-windows-10-1803

Another user report is here:
https://lime-technology.com/forums/topic/71479-windows-10-vm-cpu-usage/

Tested on: Ubuntu 16.04 with qemu 2.5.0 and i3-3217U, Arch with qemu
2.12 i5-7200U, Ubuntu 18.04 qemu 2.11.1 AMD FX-4300. All three
platform showing the same slowdown and higher host cpu load with
windows 10 1803 VM compared to windows 10 1709 VM.

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1775702/+subscriptions

costinel (costinel) wrote :

hv_synic && hv_stimer only reduces the cpu from 40-50% to 4-5%.
still expecting under 1% like linux guests.

Alex Bennée (ajbennee) on 2018-10-23
tags: added: windows10
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