> Indeed, it isn't. It's impossible with KVM (due to lacking hardware
> support) but would be feasible with TCG if you extend (or ad-hoc hack)
> QEMU code accordingly.
Why impossible? The existing watchpoints replace original physical
memory with io_mem_watch MMIO, virtual addresses are translated to
physical in exec.c:tlb_set_page(). The only missing piece is to allow
setting watchpoints with physical addresses directly.
Since KVM can handle MMIO, I think it should also be able to handle
watchpoints.