Have 2 question:
I have make PCI Passthrough for 6 Intel 82583V LAN cards into Guest VM FreeBSD 11.2 (pfSense 2.4.4), all works without any problem for Gen1 VM, on Gen2 VM PCI Passthrough did not work, even on FreeBSD 12.0 Gen2 guest VM LAN cards did not work (but Gen1 works), i have submit bug on FreeBSD forum, but it's stuck for an years:
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=222996
Maybe here can someone help with this issue?
Another problem with Passthrough of wireless devices (no matter of VM version Gen1/Gen2), as example — Qualcomm Atheros QCA986x/988x 802.11ac Wireless Network Adapter (i have 3 cards of different manufacturers, and all with same problem, not matter of Server OSes — 2016 or 2019).
When OS is booted — cards is present on Device Management, than i disable it from Device Management and run:
Dismount-VmHostAssignableDevice -Locationpath "PCIROOT(0)#PCI(1D00)#PCI(0000)" -Verbose -Force
Add-VMAssignableDevice -VMName Test -Locationpath "PCIROOT(0)#PCI(1D00)#PCI(0000)" -Verbose
Assigned VM (Gen1/Gen2) did not need to attach any VHD drive or ISO boot, just power on and power off VM (for ex. with Network boot option) — than device is absolutely dissapear from VM and Hyper-V Host OS, commands like (after Remove from VM) "Mount-VmHostAssignableDevice
-Locationpath "PCIROOT(0)#PCI(1D00)#PCI(0000)" -Verbose" says that there is no devices found.
After Hyper-V host reboot it appear again (need to Remove and Assign it again, if do not do it — VM can't start).
So, any reboot or powering off VM with attached wireless device is make device lost from the Hyper-V host and appear after host reboot. Another card — "Qualcomm Atheros QCA9984 802.11ac Wave 2 Wireless Network Adapter" generally works, but sometimes VM is looses it (on reboot or powering off) and need to cycle Remove/Add it to VM that it can start works.
There is post related to QCA988x chipsets, but formally there is problems that some BIOSes did not detect card on cold start (but in my system BIOS detects it without problems), maybe it can help to resolve issue with Hyper-V:
https://bugzilla.kernel.org/show_bug.cgi?id=84821