Kernel Panic - not syncing: cannot allocate iommu bitmap

[Stewie2k]

hi i have a Gigabye GA-970A-D3 with a FX8150 which all supports IOMMU, however when i follow the instructions from

http://pve.proxmox.com/wiki/Pci_passthrough

this is the error i get on next reboot, has anyone else had this issue.

I am using lastest ProxMox and the latest (Non Beta) BIOS that is available for this motherboard.

Any hints or help would be great thanx

 

[clinta]

Hello, I figured this deserved a response since it's the first google result for "proxmox cannot allocate iommu bitmap".

The wiki is incorrect. The correct option in grub is "amd_iommu=on".

I discovered this by booting without the iommu options specified in the wiki and got the following:

# dmesg | grep AMD-Vi
AMD-Vi disabled by default: pass amd_iommu=on to enable

Removed the options in the wiki and added amd_iommu=on and now I get:

# dmesg | grep AMD-Vi
AMD-Vi: Enabling IOMMU at 0000:00:00.2 cap 0x40
AMD-Vi: Initialized for Passthrough Mode
AMD-Vi: Enabling IOMMU at 0000:00:00.2 cap 0x40