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Old 09-08-2016, 02:28 PM   #1
razing32
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Question AMD IOMMUv2 functionality not available on this system


Hi,

I am having issues with IOMMU.
I have enable virtualization and IOMMU in the BIOS.
Based on what I found the motherboard and CPU should support this.
Yet I still get an error

vendor_id : AuthenticAMD
model name : AMD FX(tm)-8350 Eight-Core Processor

Asus M5A99X EVO R2.0


I am passing the iommu paramter via grub to the kernel :
[alin@localhost ~]$ cat /proc/cmdline
BOOT_IMAGE=/vmlinuz-linux root=UUID=7d54ccd6-a814-473e-afc0-cb21ee742839 rw quiet amd_iommu=on

However , when i check dmseg :

[alin@localhost ~]$ dmesg|grep -e DMAR -e IOMMU
[ 1.702068] AMD-Vi: Found IOMMU at 0000:00:00.2 cap 0x40
[ 3.253676] AMD IOMMUv2 driver by Joerg Roedel <jroedel@suse.de>
[ 3.253679] AMD IOMMUv2 functionality not available on this system
[ 3.263436] vboxpci: IOMMU found

BIOS Screenshot:
http://imgur.com/a/pKfD3
 
Old 09-08-2016, 04:30 PM   #2
smallpond
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You may have IOMMU but not IOMMU ver 2. Another possibility is that the message is wrong. Do ps -ef and look for [amd_iommu_v2].
 
Old 09-08-2016, 07:39 PM   #3
seasons
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I'm pretty sure the AM3(+) chipsets don't support IOMMUv2, so this is an informative message (not an error).
If your IOMMU works correctly, you should be happy with that. Some AM3 boards are flaky with the IOMMU. I know I've had to disable it or use iommu=soft to get it working right.
 
Old 09-09-2016, 01:50 PM   #4
razing32
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Quote:
Originally Posted by smallpond View Post
You may have IOMMU but not IOMMU ver 2. Another possibility is that the message is wrong. Do ps -ef and look for [amd_iommu_v2].
[alin@localhost Shadows-1.0-all]$ ps -ef | grep IOMMU
alin 13916 1452 0 20:49 pts/0 00:00:00 grep IOMMU
[alin@localhost Shadows-1.0-all]$ ps -ef | grep iommu
alin 13918 1452 0 20:49 pts/0 00:00:00 grep iommu

Nothing
 
Old 09-09-2016, 01:52 PM   #5
razing32
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Quote:
Originally Posted by seasons View Post
I'm pretty sure the AM3(+) chipsets don't support IOMMUv2, so this is an informative message (not an error).
If your IOMMU works correctly, you should be happy with that. Some AM3 boards are flaky with the IOMMU. I know I've had to disable it or use iommu=soft to get it working right.
Have not tried to go further with it since I got the error.

Someone mentioned in a different place I asked that I need AMD-Vi and seems I only have AMD-V.

Virtualization: AMD-V

Do you know any good AM3+ CPUs that support AMD-Vi/IOMMUv2 ?
 
Old 09-09-2016, 02:18 PM   #6
seasons
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Quote:
Originally Posted by razing32 View Post
Have not tried to go further with it since I got the error.
Again, it's an informational message (not an error).

Quote:
Someone mentioned in a different place I asked that I need AMD-Vi and seems I only have AMD-V.
It's the same thing, and you already have it:
Code:
[ 1.702068] AMD-Vi: Found IOMMU at 0000:00:00.2 cap 0x40
There is something called "nested page tables" or "SLAT" that helps a lot with virtualization, but most (all?) AM3 CPU's already support it. I know my Phenom II does and so does your FX-8350:
http://support.amd.com/en-us/kb-arti...yperVWin8.aspx

Quote:
Do you know any good AM3+ CPUs that support AMD-Vi/IOMMUv2 ?
Again, you already have Amd-Vi. As for IOMMUv2, it was designed for APU's (like socket FM2 chips) with integrated graphics as part of AMD's HSA. Unless you're trying to do something specific with GPGPU computing, you don't need IOMMUv2. If you just want to run a VM with good performance, you already have a capable CPU.
 
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Old 09-09-2016, 02:59 PM   #7
razing32
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Quote:
Originally Posted by seasons View Post
Again, it's an informational message (not an error).



It's the same thing, and you already have it:
Code:
[ 1.702068] AMD-Vi: Found IOMMU at 0000:00:00.2 cap 0x40
There is something called "nested page tables" or "SLAT" that helps a lot with virtualization, but most (all?) AM3 CPU's already support it. I know my Phenom II does and so does your FX-8350:
http://support.amd.com/en-us/kb-arti...yperVWin8.aspx


Again, you already have Amd-Vi. As for IOMMUv2, it was designed for APU's (like socket FM2 chips) with integrated graphics as part of AMD's HSA. Unless you're trying to do something specific with GPGPU computing, you don't need IOMMUv2. If you just want to run a VM with good performance, you already have a capable CPU.
Ahhhhh
I see.
Sorry for being so stupid.
Those errors were throwing me off.
Will give it a try and see what happens and if I get any more errors.
Just want PCI passthrough and a gaming Windows VM. That's the end goal.
 
Old 09-11-2016, 02:09 AM   #8
razing32
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It worked.
You were right seasons , it was just informational.
My machine is up and running , just need to tweak it and add peripherals.
Thanks for the help.
 
  


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