VFAT Write Crash: Error Handling Renames (macOS)

[MisutaaAsriel]

Description

When running a Windows XP host, attempting to use a VFAT (virtual FAT; folder as a FAT system) drive results in a crash once Windows finishes booting. UTM shows Error Code -5, and the message Error Handling Renames, and the Apple Crash Reporter denotes a crash in the vfat routines of QEMU.

Maybe I'm trying to use VFAT in an unsupported way, or maybe my configuration is wrong, or maybe UTM's builds of QEMU do not properly support this feature; I do not know. VFAT seems under-documented, due to the popularity of virtio-fs (viofs) and spice-webdav for file sharing. But virtio-fs has no known Windows XP drivers, and spice-webdav's service just crashes on boot with Windows XP.

Update

Attempting to use a straight VFAT device, without attaching it to the SCSI bus, (-drive file=fat:rw:/Path/To/Directory,format=raw,media=disk) crashes in the same way. I tested this in case it was the method I was attaching the VFAT disk to the VM, rather than VFAT itself, but the result was the same.

Configuration

• UTM Version: 4.6.4 (107)
• macOS Version: macOS 15.3 (24D5034f)
• Processor: M2
• Client: Windows XP Profession SP3

Crash log

• QEMULauncher-2025-01-15-152211.ips.json

Note

macOS .ips logs are an unsupported file type by GitHub; please remove the added .json to view log in its native format

Debug log

• debug.log

VM

• config.plist.zip