virtual machine strategy soptions

[Greg Troxel <gdt%lexort.com@localhost>]

Robert Swindells <rjs%fdy2.co.uk@localhost> writes:

> Aryabhata <bsdhexa%gmail.com@localhost> wrote:
>> Is there any serious momentum behind getting OpenBSD's vmm or FreeBSD's
>> bhyve working seamlessly as the frontend for NVMM? I'd much rather
>> migrate to a clean, human-maintained codebase than deal with the fallout
>> of whatever QEMU is about to merge into their tree.
>
> The interrupt handling emulation in qemu doesn't work very well when
> trying to boot Linux in a VM, is bhyve better at this?
>
> There could also be a future project to add support for virtual
> interrupts (AVIC and the Intel equivalent) to nvmm(4), then use that in
> the userspace client, this might be easier to do in a smaller codebase
> like bhyve.

I have been seeing mentions of FreeBSD bhyve for a long time and not
been clear on it.

Xen can run without qemu, in PV mode, and with qemu, in HVM.  (There is
some notion of a lightweight PV/HVM hybrid where disk/network is PV and
memory maps are HVM without qemu, but I'm fuzzy on that.)

I wonder if anyone can explain

  Does bhyve use qemu for full virtualization?  Something else?  Is
  there a PV method?   Can you e.g. boot Windows under bhyve?

  Is OpenBSD vmm related to NetBSD's nvmm?  I am guessing not, and am
  probably remembering something about nvmm in DragonFly.   It looks
  like OpenBSD's support is restricted and probably doesn't include full
  HVM operation and thus doesn't have qemu.