CPU utilisation keeps increasing, almost like a resource leak in QEMU

**Describe the issue**
CPU utilisation keeps increasing, almost like a resource leak in QEMU

This is one is a bit weird.
For the last 12 months using the same version of UTM but running Ubuntu 24..0.4 LTS (and various kernels),
the Host OS utilisation of my 4-core 4 GB ram VM hovered around 40-50% of one core.
It trundled along perfectly happily occasionally using more host CPU for a while is the guest OS was doing something big, but it always returned to its original very moderate levels.
Guest OS like trundled along at about 20-35% utilisation of a one core.

With the advent of 26.0.4, nothing much changed until I upgraded to Host OS MacOS 26.5.2 and until Guest OS Ubuntu 26.0.4, kernel 7.0.0-22 and 7.0.0-28.

With these newer kernels now, the Host OS CPU utilisation of UTM QEMU has not only jumped to 100% of one core but now it slowly and steadily increases on a daily basis.
I have seen it reach 200% before I stopped the VM and restarted it - full utilisation of 2 cores on the Host OS!
But all the while the Guest OS still trundles along at the same old 20-35% utilisation of just one out of its 4 cores.

I've read the existing issues about increasing Host OS CPU usage and reset all of the network interfaces in the Guest OS but nothing seems to make any difference.

I'm completely stumped.

The version of UTM I'm using never used to do this.
Everything seemed fine under the previous Host OS MacOS 26..5.1 and the earlier Ubuntu 7 kernels,
but now there seems to be resource leak in QEMU.

I would appreciate any direction or advice about how to further debug this.

**Configuration**
* UTM Version: 4.7.5 (from the Mac App Store, not the Freeware version)
* macOS Version: 26.5.2
* Mac Chip (Intel, M1, ...): M4 Max
* Guest OS: Ubuntu 26.04, kernel 7.0.0-28

**Crash log**
None
**Debug log**
Attached

[debug.log.zip](https://github.com/user-attachments/files/30294517/debug.log.zip)

**Upload VM**
Attached

[config.plist.zip](https://github.com/user-attachments/files/30294509/config.plist.zip)

Start by reviewing the attached debug.log.zip and config.plist.zip, then reproduce the increasing host CPU usage with UTM 4.7.5 on the stated macOS, Ubuntu, and kernel versions. Compare the behavior with the earlier host and kernel versions mentioned in the report. Done means identifying the cause of the increasing QEMU CPU usage and verifying that it no longer grows during extended VM operation.

Written by the indexing model from the issue text.