How to enable IOMMU in Fedora

原文：https://scottlinux.com/2017/05/10/how-to-enable-iommu-support-in-fedora-linux/

Typically by default, IOMMU is not enabled in Linux. I’ll show how to enable that virtualization feature on Fedora Linux!

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1. First, check if IOMMU support is enabled by running this command:

sudo virt-host-validate

If in the output you see something similar to the following, continue on below for help.

...  QEMU: Checking if IOMMU is enabled by kernel                               : FAIL(IOMMU appears to be disabled in kernel. Add intel_iommu=on to kernel cmdline arguments)...

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2. Edit the file /etc/default/grub and add intel_iommu=on to the existing GRUB_CMDLINE_LINUX line.

Note: I have a lot going on here for mine, such as a fix for a weird usb power issue of my motherboard, enabling nested virtualization for kvm and more. Disregard those things and only add intel_iommu=on for this task!

GRUB_TIMEOUT=5GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)"GRUB_DEFAULT=savedGRUB_DISABLE_SUBMENU=trueGRUB_TERMINAL_OUTPUT="console"GRUB_CMDLINE_LINUX="nouveau.modeset=0 rd.driver.blacklist=nouveau nomodeset rhgb quiet xhci-hcd.quirks=262144 kvm-intel.nested=1 intel_iommu=on"GRUB_DISABLE_RECOVERY="true"

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3. Next, update grub2 via:

sudo grub2-mkconfig -o /boot/grub2/grub.cfg

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4. And finally reboot.

sudo reboot

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Now IOMMU should come back as PASS in this check: Run virt-host-validate again.