bhyve PM timer should be movable
One device emulated by the bhyve kernel module is the power management timer (vpmtmr). Presently it is accessible via ioport
0x408 (corresponding to a
0x400). While this @PMBASE location might match certain traditional hardware system, it conflicts with ioport that qemu uses for certain device emulation (such as the debug port at
0x402) The rest of the ACPI functionality (offset from
PMBASE) is implemented in userspace, but without the ability to update the in-kernel IO port for the PM timer, relocating it is not possible.
The IO port handling in the bhyve kernel should be more flexible so the PM timer, at the very least, can be relocated to a different IO port.