High host CPU load and slower guest after upgrade guest OS Windows 10 to ver 1803 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. This bug affect me 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"