AMD Ryzen IOMMU and the B350 Chipset Challenges

Zarathustra[H]

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While Ryzen certainly is a very tempting platform for virtualization on the cheap, we have reported before that it may not be quite there yet. ServeTheHome has had some further relevant issues with their Ryzen system on the B350 platform with certain configurations resulting in an ADM-Vi error before the system is fully booted.

While I am certain these things will be solved in time, it does go to show that right now is probably not the best time to build a virtualization box using Ryzen. As the Magic 8-Ball says, "Try Again Later".

A lot has been made about AMD Ryzen ECC support at launch. Since we now have several Ryzen test platforms we are managing demos on, the discussion on ECC memory, at this point, is misplaced. There are a myriad of platform issues that still need to be ironed out, such as this AMD Ryzen B350 IOMMU issue, memory support, and OS kernel patching, before one will need to worry about ECC memory on the Ryzen platform. We do think that the AMD Ryzen platform will be a winner in the low-end 1P server market several months from now when the platform matures and we get appropriate motherboards (e.g. with iKVM and IPMI.) Although we do advise against buying these systems today for mission-critical services, we have told executives at AMD and multiple server vendors that these will be category killer 1P server platforms if a mature platform hits the market.
 
Oh no, need my workstation to support VMs, wonder if this affects x370 boards, might need to re-spec some machines.
 
Oh shit. I hate paying for expensive motherboards with tons of useless features. IOMMU is a must have. Fix it, fix it, fix it
 
Oh no, need my workstation to support VMs, wonder if this affects x370 boards, might need to re-spec some machines.


I don't think anything would stop you from running typical desktop style VM's on either platform. You don't need IOMMU for that. IOMMU becomes important when you want to try to pass through hardware. So it will depend on your implementation / use scenario.

Either way, it will likely be fixed in time.
 
Oh no, need my workstation to support VMs, wonder if this affects x370 boards, might need to re-spec some machines.

As Zarathustra said, this is only about PCI-E passthrough. There is no problem having virtual machines with CPU acceleration (AMD-V), i am running 9 virtual machines in VirtualBox at this moment, uptime around 3 days (with kernel 4.11-rc1 on Ubuntu 17.04 daily).
 
Oh no, need my workstation to support VMs, wonder if this affects x370 boards, might need to re-spec some machines.



I don't think anything would stop you from running typical desktop style VM's on either platform. You don't need IOMMU for that. IOMMU becomes important when you want to try to pass through hardware. So it will depend on your implementation / use scenario.

Either way, it will likely be fixed in time.


Nothing to fear:
There is no issues with IOMMU as far as I can see apart from multigpu support, as in assigning a GPU - One gpu for VM and one for host OS will not work, Or I cannot get it working.
Drives, nic's and other random devices seem to assign nicely.

if you do not do graphical intensive gpu passthrough activities you can rely on a Ryzen chip.
Remember, GPU Accelerated works without gpu passthrough in vmware.
 
Nothing to fear:
There is no issues with IOMMU as far as I can see apart from multigpu support, as in assigning a GPU - One gpu for VM and one for host OS will not work, Or I cannot get it working.
Drives, nic's and other random devices seem to assign nicely.

if you do not do graphical intensive gpu passthrough activities you can rely on a Ryzen chip.
Remember, GPU Accelerated works without gpu passthrough in vmware.
Ok whew. I'm running KVM and Hyper-V workloads depending on which OS I'm running for the day. Basic VM support is okay but I do want to eventually test features I might try in server form and I guess these things will get ironed out for those chipsets anyhow.
 
Esxi or workstation?

Sorry for the noob question.

Workstation, never done "non passthrough gpu" on esxi.
However!
I can test esxi as I have a 6950 sitting idle and a esxi system which does not support proper VM passthrough.
 
While FreeBSD boots fine on Ryzen, I'm really wanting to do PCI-E passthrough of a graphics card to a VM using Bhyve. Now I'm hesitating. Good thing I have a beefy Intel machine to hold me over in the mean time, but man, I miss the days of being an AMD fanboy.
 
While FreeBSD boots fine on Ryzen, I'm really wanting to do PCI-E passthrough of a graphics card to a VM using Bhyve. Now I'm hesitating. Good thing I have a beefy Intel machine to hold me over in the mean time, but man, I miss the days of being an AMD fanboy.


I get the impression (but I am not sure) that this works with an X370 based motherboard. Just not with a B350.

I could be wrong though, so don't quote me on it.
 
I get the impression (but I am not sure) that this works with an X370 based motherboard. Just not with a B350.

I could be wrong though, so don't quote me on it.
This is definitely an issue on the Asus ROG Crosshair VI Hero. Broken IOMMU support and I have issues with my HotLava Shasta six-port NIC as well. It is a known-good NIC with (I believe) a PLX chip on it and three dual-port Intel 82576EB chips on it. So far, so bad with x370. Arg. :(
 
There are issues with certain PCI-E hardware in general, not just related to IOMMU. For example in early days, i could not even get my IBM M1015 (flashed ti 9211-8i IT) working, Ubuntu boot did hang with the card in place. After getting my PRIME X370 PRO up to 0604 BIOS, the card finally works. At same time, a simple PCI-E x1 ASM1062 card is unable to communicate with a hard drive connected it, the SATA link goes dead. Same card, same hard drive, same cable, transplanted to a Z170 system, absolutely no problems with it.
 
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