GA-890FXA-UD5 IOMMU BIOS Switch?

[kuzew]

Hello,

I am attempting to do virtualization under Debian GNU/Linux (x86_64) using KVM (Kernel-based Virtual Machine). The Linux Kernel has the ability to utilize the Input/Output Memory Management Unit (IOMMU) [1,2] which is available in the northbridge chipset of the GA-890FXA-UD5 motherboard. The chipset, AMD 890FX (aka RD890) has been reported numerous times to support IOMMU [3,4,5,6] which made me go off to buy this motherboard, for this chipset. By using the IOMMU, I can do AGP and PCI passthrough to the virtual machine using the Graphics Address Remapping Table (GART), which is done by the IOMMU. Well, it seems I don't have IOMMU enabled, according the the boot logs on Linux.

Within the BIOS (latest version F2), there is only a switch for virtualization and that is it. Even under the "advanced" settings (Ctrl+F1) there is still no switch for IOMMU related configurations. Did I miss something here?

So my question is (finally), will there be support for this option on this motherboard for this northbridge chipset in the near future? Or should I return this motherboard because it is just not wired for IOMMU and there is no way the BIOS vendor will support this? Or is it already setup and turned on (with no switch in the BIOS) for IOMMU and I'm just configuring Linux the wrong way (the hardware configuration is fine)? Am I doing something totally wrong here?

Thank you for your time and effort.
Cheers,

kuzew

[1] - http://en.wikipedia.org/wiki/IOMMU
[2] - http://developer.amd.com/documentation/articles/pages/892006101.aspx
[3] - http://www.pcstats.com/articleview.cfm?articleid=2515&page=2
[4] - http://en.wikipedia.org/wiki/AMD_800_chipset_series
[5] - http://techreport.com/articles.x/18825
[6] - http://www.tomshardware.com/reviews/amd-phenom-ii-x6-1090t-890fx,2613-4.html

[autotech]

honestly i bet it is your bios. I dont know what processor you are using but in f-2 bios my cpu runs at 800 mghtz only and all kind of glitches. The original bios wasnt much better. c1e couldnt be disabled and many other glitches.  So until they decide to get the bios right i dont think this board is going to work right. You can submit a support ticket but i have 2 times and no answer to either i think gigabyte just doesnt care or doesnt have the man power to fix it right.

Its what we get for buying the newest and greatest. Myself i wont buy gigabyte again will go to asus and try them. Would have to have a good bios to even consider staying with gigabyte.

[kuzew]

honestly i bet it is your bios. I dont know what processor you are using but in f-2 bios my cpu runs at 800 mghtz only and all kind of glitches. The original bios wasnt much better. c1e couldnt be disabled and many other glitches.  So until they decide to get the bios right i dont think this board is going to work right. You can submit a support ticket but i have 2 times and no answer to either i think gigabyte just doesnt care or doesnt have the man power to fix it right.

Its what we get for buying the newest and greatest. Myself i wont buy gigabyte again will go to asus and try them. Would have to have a good bios to even consider staying with gigabyte.

Yeah, I wouldn't be surprised. Even more so, Windows 7 has yet to implement IOMMU in any of their virtualization software/in the kernel, so it would be less of an insight for a BIOS vendor to enable it. I've been told to look at the server motherboards that aren't Gigabyte to see if they have the IOMMU switch in their BIOS. But I'm really surprised that I didn't find it in this BIOS because virtualization is a hot button issue now and I'd think that would be a selling point... but maybe not for a desktop motherboard? I do have a ticket in their technical support complaining about this which I submitted two days ago -- lets see if they reply.

The Award BIOS has every option on the face of the Earth for memory timing and clock adjusts, but when it comes in tweaking what is fully on the board it has come up short. I'm still impressed though about the control of memory and frequencies it has to offer, something to play with later if I have time.

My processor is a AMD Phenom II X3 unlocked to 4 cores, BTW. I just hope it is in the works... I can wait for the feature to be fully enabled, but if it's not then that was a waste of a good northbridge chipset. That seems to be the problem with this feature I've read on mailing lists, it's the screw ups in the BIOS where it wasn't implemented properly or at all. This is fairly new so yeah, it might be some time to see it come downstream.

Thanks for your input, cheers!

[autotech]

Cheers and you welcome. Makes me wonder if under windows 7 ultimate winows xp mode is a type of virtualization. I do see the swich for it in bios but not for  IOMMU under a linux kernel makes me wonder if there will ever be one as i think windows left it out on purpose, They wouldnt promote linux l ose 2 much money and some people want total control over their sysytems.