Disabling tsc flag on windows host allows Broadwell, Haswell and other cpu architectures to boot normally

Host environment:

  • Operating system: Windows 11

  • OS/kernel version: Windows 11 Version 22H2

  • Architecture: x86_64

  • QEMU flavor: qemu-system-x86_64

  • QEMU version: 10.0.3

  • QEMU command line:

    ./qemu-system-x86_64.exe -m 4G -M q35 -accel whpx,kernel-irqchip=off -cpu Haswell,-tsc -smp 6 -device usb-tablet -usb -device virtio-vga-gl -display sdl,gl=on -hda D:\Artix.qcow2

Emulated/Virtualized environment:

  • Operating system: Any Linux Distro
  • Architecture: x86_64

Description of problem:

When attempting to boot a virtual machine with Broadwell, Haswell or any other CPU architectures except Westmere on a Windows 11 host, the system fails to boot (either freezing at grub bootloader or black screen) unless the TSC flag is disabled. Disabling the TSC flag resolves the problem and allows the VM to boot normally.

Steps to reproduce:

  1. Launch QEMU with the -cpu broadwell or -cpu Haswell flag on a Windows 11 host.
  2. Observe that the virtual machine fails to boot or experiences instability.
  3. Disable the TSC flag using -cpu Haswell,-tsc.
  4. Boot the virtual machine again.
  5. Notice that the VM boots successfully and runs without issues.

kindBug hostos: Windows

Edited Jul 29, 2025 by Jay Patil
Assignee Loading
Time tracking Loading