Aurora R10, BIOS 2.2.1 disabled IOMMU, need downgrade

I wouldn't consider this thread as "Solved", because latest BIOS update broke my whole setup and there is no way for me to fix it - Dell is software blocking the downgrade.
Since there are some Dell employees looking through this forum, maybe one of them can answer these questions:
1. Why the change log for the latest BIOS update doesn't mention anything about disabling IOMMU?
2. Will the next BIOS update have IOMMU enabled or (better) add the option to enable/disable IOMMU in BIOS.
3. Is buying new non Dell hardware the only option to fix my current problem?

I can only answer #3. I am sure there's a fix in the works for the reported issues with this bios.

I would check the Dell driver download section from time to time, to see if a new bios update is available.

I do agree with you that a more detailed change log would be a welcome change.

All it lists is this:

Fixes:
- Fixed the issue where the BIOS cannot be updated using Dell SupportAssist.

It obviously contains a lot more than just that 1 update:

Dell Technologies highly recommends applying this important update as soon as possible. The update contains critical bug fixes and changes to improve functionality, reliability, and stability of your Dell system. It may also include security fixes and other feature enhancements.

Dell drivers page 

I agree 100%, they need to do a better job with the change log information so users have a better understanding of the effects of the update. If it would have said they disabled IOMMU, than I am sure you would have skipped this update.

Please fix IOMMU

Updating via support assist soft bricked my Aurora. Even the bit they listed was a fail

Did you try the latest BIOS version for the R10?

Yes, I updated the BIOS to version 2.2.2, but there is no change. IOMMU is still disabled:

I am beyond disappointed with Dell for not including in the release notes that IOMMU would be disabled and it still is not fixed.  I have applied the most recent BIOS update from April 2022 with no change.  I purchased an R10 - first non-HP system in a long time.  I have multiple HP Desktops (much older) that have no issues with IOMMU or BIOS updates, release notes, etc.

For anyone at Dell that might be paying attention - even if there isn't a large # of people complaining about this, it is probably the most tech-savvy people that it affects and they are often asked about PC buying advice.  My advice will be to stick with others based on such an amateurish mistake. 

@sh run 

Since its for VM's (Virtual Machines) have you checked the other bios settings for VM? Other vendors UEFI BIOS, this feature is in "Advanced -> CPU configuration" and is called SVM (Secure Virtual Machine), or AMD-V or AMD Virtualization.

IOMMU is Intel's name for VT-x (virtual memory & execution) and VT-d (virtual PCIe addressing for peripherals).

Clearing cmos entirely then re setting may also change things.

There is zero linux support for the R10 Ryzen models or any other Dell model that did not ship with Linux.  Dell only supports the OS that shipped with the unit.

It is indeed for Linux - Proxmox in particular.  I understand that Dell does not support any other OS other than what it supplied but that is not the problem.  They have disabled a hardware feature.  IOMMU is NOT just for Intel - AMD_IOMMU=ON is a setting that works for AMD processors.  Unfortunately, Dell disabled IOMMU on the R10 with a BIOS update and is not allowing a downgrade or fixing it.

It's odd because on my R10 it was always enabled.

You can try downloading default BIOS settings, and see if more options appear?

I appreciate the advice but Dell has blocked any BIOS downgrade to a level that re-enables IOMMU.  Others have complained about this including the OP.

Has anyone confirmed what version of BIOS still had IOMMU enabled by default?  Was is 2.1.3 and 2.2.1 disabled it?  I see there are "BIOS recovery images" (for corrupted BIOS).  Has anyone tried a downgrade via that method?

Yes, 2.1.3 had IOMMU enabled by default (tested on Unraid). I tried every method that I could find on the web to downgrade the BIOS, but without success. There were some methods, that worked on previous BIOS versions, but Dell blocked them all. The only option is to buy new motherboard, PSU, Case and CPU cooler - which I did.

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