Sections

Highlights

  • QEMU v9.1.2 The backend has been updated to the latest upstream QEMU which brings with it a variety of bug fixes and performance improvements.
  • macOS 15 Nested virtualization for Linux Linux VMs using Apple Virtualization backend on macOS 15 and M3 or newer will now have nested virtualization enabled by default.
  • macOS 15 Total Store Ordering for QEMU VMs using QEMU backend on macOS 15 can now enable TSO (in QEMU settings) at the hypervisor level. When TSO is enabled on a guest operating system that is aware of the system register (i.e. Rosetta for Linux), performance of Intel emulation within the guest can be greatly improved. Note that if the guest kernel supports dynamically toggling TSO, you do not need to enable this.
  • macOS 15 Improved macOS guest support The last window size (including full screen size) will be restored when the guest supports dynamic resolution. Removable drives and shared directories can now be ejected and changed while the macOS VM is running. Copy/paste synchronization between macOS 15 guest and host now works when the guest tools are installed (from the CD icon in the toolbar).

Notes

  • macOS There is a known issue with macOS 15.0 and 15.0.1 where accesses to files will fail due to permission error. This issue has been resolved with macOS 15.1.
  • macOS There is a known issue on M4 series of Macs where virtualization fails for macOS guests older than 13.4. The issue should be addressed by Apple in a future update. (#6794)
  • There is a known issue (#6332) with Windows 11 24H2 that causes the display to show a black screen or “Guest has not initialized the display (yet)” upon boot. We recommend not upgrading to 24H2 for existing installs and 23H2 for new installs. If you have already upgraded, please follow the workaround described in the linked issue.
  • The default CPU for x86_64 emulation and virtualization will now try to match the architecture of your system or the highest architecture that QEMU supports. For example, a 2016 MacBook Pro or newer will now emulate a “Skylake” based processor instead of a generic x86_64 processor. This should improve compatibility and performance of newer operating systems but may cause issues with older operating systems. If you run into issues, you can manually change the CPU model to an older one in the VM’s System settings.
  • The update to QEMU v9.1.2 will likely introduce other issues and regressions. If you experience any problem (crashes, performance, errors) that was not evident in v4.5.x, please open an issue and provide all the requested information. It would also be helpful if you can provide a reproducible example and note the last version of UTM where it worked properly.

Changelog

The full list of changes can be found on GitHub.