From the CPU side there is no issue in IOMMU, at least for Ryzen, dunno about TR. ESXi and Xen are working properly, but this is no alternative to KVM for me.
You are correct about the Xen and ESXi part, however for me that is no alternative either since i want to use Unraid server OS.
I love unraid and started with a trial and later on ordered the full license, and now i want to build a decent machine for it. but the KVM_amd messes up al the IOMMU stuff, there are here and there tricks that lots of people mention. but that is not something i want to rely on when i build a new machine where the CPU only is already 1.1k. But i have a couple of months to go before i have my budget complete and will decide at the time that my budget is complete.
And to end with is that I love unraid/kvm more then the alternatives. I really hope the issue is solved when i will start my purchase if it is not. i have to settle for a 1k i9 instead of the amd tr 1950x.
Again the TR is a beast and i want it, but for now it is not working with my software. (atleast not how i want it too)
I thought you can decide which hypervisor (kvm or xen) you want to use with unraid? But correct me if I'm wrong, never had my hands on it.
So @ ray_m or anyone else official:
You told us that the issue has been escalated, but again weeks passed w/o anything, no confirmation, no statement just nothing...
So it was escalated from "ignore it" to "ignore it even harder"???
This is the only place where we could get official support, as you do not offer any E-Mail address, but you are not supporting anything.
I think you know that this is impertinent on how you deal with your costumers or costumers in future.
Highly unlikely. The issues on X399/Threadripper are not enabling IOMMU, but a mess of general PCI bus issues and compatibilities. A handful of common USB/LAN/SATA cards make systems not post at all or have various compatibility issues, and GPU cards in particular tend to get stuck in power saving mode. Varying models of both Radeon & Nvidia GPUs get permanently stuck in D3 state when put into it - and this is regardless of passthrough, the same thing happens on OS sleep/resume. It just also blocks pass-through at all because VFIO will put the card in D3 until the VM is started and will be unable to wake it. The only possibility would be if the user has a GPU magically not affected by this issue, and, from what I can tell - that would have to be a GPU whose power saving mode is completely broken due to a driver or bios issue.
Nope, that does not work.
Atleast not on Threadrippers. Starlightknight explaines it accuratly, i.e the Vega cards are bugged with regards to the reset/power-thingy and can be passed to a VM. Still affected by the NPT bug though.
Well, it's good to see that they're fixing up this IOMMU grouping issue on TR (or at the very least, that person's 1050ti was in a group by itself, which is progress), but that doesn't fix the main problem behind the thread. Unless you were responding to someone else's comment; looked like you might be posting this as a solution to the main thread.
The main issue is that AMD processors seem to be unable to passthrough graphics cards on KVM when NPT is enabled (they can pass them through, but performance takes a massive hit).