bhyve passthrough problem after updated host to 10.3

Peter Grehan grehan at
Mon Feb 27 00:09:21 UTC 2017

Hi Sergey,

>> Now, after experiments I can say the card can work only on 2 slot and
>> function=function on host.
>> Example:
>> -s 2:1,passthrough,3/0/1
> It's even worse I thought.
> The network card work only if spare slot with a disk device (may be any
> device, I did not try).
> So, it works:
> -s 2:1,passthru,3/0/1 -s 2:0,virtio-blk,mydisk
> and it does not work:
> -s 2:1,passthru,3/0/1 -s 3:0,virtio-blk,mydisk

  Guests in general won't probe non-zero functions if function 0 is not 
present. Putting something at function 0 allows the device probe to be 
extended to the non-zero functions you have configured.

> It does not make a sense for me. Only idea is the network card is a
> quad-port card. And its driver need to have any device in the same slot
> with 0 feature (to initialize PHY?). Because of my host system is
> connected to first ethernet I can't passthrough it to guest and test the
> theory.

  Certain PCI devices do have dependencies between functions (e.g. 
certain Qlogic FC adapters), while others are independent (Intel 
multi-port NICs). This part is probably a case of the former.

  I'd suspect that if you passed the entire device through (and matched 
function numbers) to a guest, it would work. However, as you have 
mentioned, a port needs to be dedicated to the host :(



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