Issues with GTX960 on CentOS7 using bhyve PCI passthru (FreeBSD 11-RC2)

Peter Grehan grehan at
Sat Jan 14 07:13:14 UTC 2017


> Does bhyve not execute peripheral cards' option ROMs?

  Not yet.

> I guess it doesn't. This could explain a lot of strange
> behaviour seen resulting from running in a VM.


> How does UEFI work in this regard? My guess is that cards
> have to explicitly support the new boot method (UEFI)?

  Yes - an additional section in the option ROM is needed, but as 
mentioned in an earlier email, that support is now widespread thanks to 

> So passthrough with newer cards may be easier? This could
> explain why the newer RX 480 worked right away, and the
> older Quadro 2000 (and a lot of other nVidia cards without
> manufacturer's support for VMs) had no chance -- UEFI cards
> are somehow more "autonomous".

  Possibly, though it might also be the card itself not requiring as 
much initialization from the option ROM.

> It all is just speculation on my side, I know nothing about
> this UEFI stuff.
> Could you summarize in couple sentences what's the deal between
> bhyve and UEFI (if there is any), or future plans?

  UEFI is the ROM firmware for bhyve (and most modern PCs). bhyve has a 
custom build of the standard Intel EDK2 distribution:

  The changes are to support running as a hypervisor guest, where a lot 
of what is in a normal boot ROM isn't required (e.g. DRAM controller 
setup, CPU microcode update), and it also contains drivers for device 
emulations supported by bhyve.

  Currently, the ability to process an option ROM has been disabled.



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