vm(apple): support USB passthrough on macOS 27

[shanginn]

Summary

• Add USB passthrough for Apple Virtualization macOS guests on macOS 27 using Accessory Access and the public Virtualization USB APIs.
• Add USB discovery, connection, and disconnection controls to the Apple VM display menu.
• Preserve connected-device intent across VM starts and safely detach and restore devices around pause, saved-state, resume, and restart operations.
• Serialize hot-plug and VM lifecycle operations and release device ownership when the VM stops.
• Add the Claim USB Accessory capability to provisioned macOS builds while keeping ordinary unsigned packages launchable.

Resolves #3778

Signing

USB passthrough requires a provisioning profile containing the com.apple.developer.accessory-access.usb entitlement.

The entitlement is intentionally excluded from macOS-unsigned.entitlements, because macOS rejects an ad-hoc signature containing this restricted entitlement on normally protected systems.

I dont have a developer account so I cant make a proper build of that. And it was tested with SIP disabled

Testing

Tested on a MacBook Pro (Mac14,6, Apple M2 Max) running macOS 27.0 beta 4 (26A5388g), using a macOS 10.15.7 Apple Virtualization guest and an ASolid USB_0114 mass-storage device (VID:PID 24a9:205a). Confirmed assigning the device to UTM, connecting it to the guest, and using USB sharing successfully.

Built an arm64 Release archive with Xcode 27 beta 4 (27A5228h) and the macOS 27 SDK. The beta toolchain required a command-line-only macOS 12.0 deployment-target override; this change does not modify UTM’s deployment target.

AI assistance

I have read the AI contribution guidelines and have followed them to the best of my ability.

This implementation was developed with assistance from GPT-5.6 sol. Although I'm not a swift developer I reviewed the resulting code. The tests were done tested manually, but not extensivly.

[Dilergore]

will this support USB Audio/Video Devices as well?

[shanginn]

will this support USB Audio/Video Devices as well?

sadly no. at least my external Web Camera uses USB isochronous endpoints for UVC video/audio. Apple’s macOS 27 Beta 4 Virtualization runtime explicitly rejects it with: A USB passthrough device with isochronous endpoints is not supported.

and double sadly this feature was actually needed for the webcam passthrough (but I was waiting for the usb webcam to arrive to test it)

[Dilergore]

will this support USB Audio/Video Devices as well?

sadly no. at least my external Web Camera uses USB isochronous endpoints for UVC video/audio. Apple’s macOS 27 Beta 4 Virtualization runtime explicitly rejects it with: A USB passthrough device with isochronous endpoints is not supported.

and double sadly this feature was actually needed for the webcam passthrough (but I was waiting for the usb webcam to arrive to test it)

I think all the cameras and most probably headsets as well use isochronous. This is very sad, i really hope they will add support for this in a future beta.