After upgrade qemu to 5.0.0-0.3.rc2.fc33 the virtual machine with Windows 10 after a while starts to work very slowly

[Mikhail Gavrilov]

Description of problem:

After upgrade qemu to 5.0.0-0.3.rc2.fc33 the virtual machine with Windows 10 after a while starts to work very slowly

I created the virtual machine with Windows 10 with the following config:
- 1 CPU
- 2GB RAM
- With network access

I launch there a web browser there with flash content.
And usually, the system (Windows 10) does not work there for more than an hour.
When the system starts to work very slowly it doesn't respond to "Reboot" and "Shut Down" commands. Only works "Force Reset" and "Force Off". But when I reboot the system with "Force Reset" it usually stuck at boot at the Windows splash screen. https://imgur.com/yGyacDG

The last version of qemu which not contain this issue is 5.0.0-0.2.rc0.fc33

[Mikhail Gavrilov (mikegav)]

When VM starts work very slowly System interrupts in Windows Task Manager eats up 99% of all CPU resources.

[Stefan Hajnoczi (stefanha)]

Please try this patch series: https://lists.gnu.org/archive/html/qemu-devel/2020-05/msg02728.html

[post-factum (post-factum)]

Unofficial x86_64 build of v5.0.0 with those 2 patches for Arch is here: [1].

[1] https://download.opensuse.org/repositories/home:/post-factum/Arch/x86_64/

[Mikhail Gavrilov (mikegav)]

I confirm that with patches https://lists.gnu.org/archive/html/qemu-devel/2020-05/msg02728.html Win 10 in QEMU working already more than 24 hours without issue.

[Thomas Huth (th-huth)]

The patches mentioned in the previous comments have been released with QEMU v5.1, so I'm marking this bug as fixed now. If you still have problems, please open a new ticket.