The Elephant in the room: AM4/TR4 Chipset IOMMU separation

[FurryJackman]

Yes, but my problem is I need direct access to the onboard NICs and that’s still lumped together.

I currently run X79 and that’s not a problem. I can even run a proper USB 3.0 controller like this:

Jack's Hardware: The Ultimate VFIO USB 3.0 Controller

After testing MANY USB 3.0 controllers and researching which ones work best with VFIO, I’ve now landed on this solution for the ULTIMATE VFIO USB 3.0 controller card. I had another thread where I vented out my frustrations with XHCI and Linux, and that has a little bit of info on woes regarding which controllers 100% work for VFIO and GPU passthrough: Through all that frustration, I came to the solution for a proper USB 3.0 controller for QEMU/KVM passthrough… The Startech PEXUSB3S24. This supports Message Signaled Interrupts which is required for consistent data streaming. (USB Video and Audio data for instance) Interestingly, the same concept as that applies for the HD Audio controllers on GPUs which also need Message Signaled Interrupts to prevent audio streams from becoming garbled/warped. This card is also one of the rare USB 3.0 controller cards that support proper resetting, which means reboots of the VM won’t cause any system lockups or other issues like the 127 issue. I tell you, coming from a Fresco Logic controller that didn’t support proper resetting… (even though it may indicate it can support resetting when listing it’s PCIE functionality) having to cold boot the machine everytime to boot the VM was a nightmare. The reason this works so well is because the controller comes pre-loaded with the latest firmware (even newer than the 2.0.2.0 firmware on Startech’s site) and is based off of the uPD720202 from Renesas. This controller also requires no manual installation of drivers for Windows 8.1 and Windows 10 VMs. I believe Message Signaled Interrupts are also automatically switched on when you reveal the card to Windows. [vlcsnap-2018-12-03-21h59m19s516] Problem 1 solved. We now have a proper USB 3.0 controller that with the SATA power connected, gets around USB power management issues… But we have more than one problem on our hands… Our 2nd problem is fitting this card underneath a MASSIVE GPU like my STRIX GTX 1080 11Gbps… [vlcsnap-201…