Virtualization

TODO: Add description

Print iommu groups:

Prints out all iommu groups on the system, this can be useful if you are trying to see if you need to remap them for pcie passthough.

shopt -s nullglob
for g in $(find /sys/kernel/iommu_groups/* -maxdepth 0 -type d | sort -V); do
    echo "IOMMU Group ${g##*/}:"
    for d in $g/devices/*; do
        echo -e "\t$(lspci -nns ${d##*/})"
    done;
done;

shopt -s nullglob: This command sets the nullglob option in bash, which changes the behavior of bash when no files match a glob pattern to return an empty string rather than the pattern itself.

for g in $(find /sys/kernel/iommu_groups/* -maxdepth 0 -type d | sort -V); do: This starts a loop over each IOMMU group. The find command is used to list all directories in /sys/kernel/iommu_groups/, and sort -V sorts the output in version number order.

echo "IOMMU Group ${g##*/}:": This prints the name of the IOMMU group. ${g##*/} is a parameter expansion that removes the directory part of $g, leaving just the group number.

for d in $g/devices/*; do: This starts a nested loop over each device in the current IOMMU group.

echo -e "\t$(lspci -nns ${d##*/})": This prints the details of the device. lspci -nns ${d##*/} is used to get the device details from lspci, a utility for displaying information about PCI buses and the devices connected to them. ${d##*/} is a parameter expansion that removes the directory part of $d, leaving just the device number.