illumos gate

Up until #13637 was integrated, vioif interfaces ignored requests to enable promiscuous mode, but returned success.
This allowed VNICs to be created on top of vioif interfaces and, with some additional configuration, they could be used.

The usual way that I used this was to create a VNIC in the global zone, and assign some secondary mac addresses to it via the secondary-macs property.
That VNIC is then allocated to a bhyve VM, and the guest sees a vioif interface.
The guest creates one or more VNICs over that vioif, explicitly setting the MAC addresses to match those assigned to the GZ VNIC's secondary-macs.

Here is an example configuration that worked prior to #13637

Global zone:

reaper# dladm show-vnic omniosr0
LINK         OVER       SPEED MACADDRESS        MACADDRTYPE VID  ZONE
omniosr0     switch10   0     2:8:20:10:1c:b6   random      0    bloody

reaper# dladm show-linkprop -p secondary-macs omniosr0
LINK         PROPERTY        PERM VALUE          DEFAULT        POSSIBLE
omniosr0     secondary-macs  rw   a:0:0:0:0:1    --             --

In the bhyve guest that is assigned omniosr0:

bloody% dladm
LINK        CLASS     MTU    STATE    BRIDGE     OVER
vioif0      phys      1400   up       --         --
switch_10   etherstub 9000   up       --         --

bloody% pfexec zadm boot lx

bloody% dladm
LINK        CLASS     MTU    STATE    BRIDGE     OVER
vioif0      phys      1400   up       --         --
switch_10   etherstub 9000   up       --         --
lx0         vnic      1400   up       --         vioif0

bloody% dladm show-vnic
LINK         OVER       SPEED MACADDRESS        MACADDRTYPE VID  ZONE
lx0          vioif0     1000  a:0:0:0:0:9       fixed       0    lx

bloody% pfexec zlogin lx
[Connected to zone 'lx' pts/2]
# ping 1.1.1.1
PING 1.1.1.1 (1.1.1.1) 56(84) bytes of data.
64 bytes from 1.1.1.1: icmp_seq=1 ttl=56 time=6.34 ms
^C

Now that vioif properly supports promiscuous mode, but while the bhyve viona driver does not, it would be helpful if the previous behaviour could be restored to allow this type of configuration to continue working.