en Copyright 2015 Java http://kernelsources.org:8080/source/history/linux/tools/testing/selftests/vfio/lib/include/libvfio/sysfs.h#c5db77a035e1291e2c9b488073c28b441e5e44f3 vfio: selftests: Introduce a sysfs libIntroduce a sysfs library to handle the common reads/writes to thePCI sysfs files, for example, getting the total number of VFs supportedby the device via /sys/bus/pci/devices/$BDF/sriov_totalvfs. The librarywill be used in the upcoming test patch to configure the VFs for a givenPF device.Since readlink() is quite commonly used in the lib, introduce and usereadlink_safe() to take care of potential buffer overrun errors and tosafely terminate the buffer with '\0'.Opportunistically, move vfio_pci_get_group_from_dev() to this library asit falls under the same bucket. Rename it to sysfs_iommu_group_get() toalign with other function names.Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>Reviewed-by: Vipin Sharma <vipinsh@google.com>Reviewed-by: David Matlack <dmatlack@google.com>Tested-by: David Matlack <dmatlack@google.com>Link: https://lore.kernel.org/r/20260505212838.1698034-4-rananta@google.comSigned-off-by: Alex Williamson <alex@shazbot.org> List of files: /linux/tools/testing/selftests/vfio/lib/include/libvfio/sysfs.h Tue, 05 May 2026 23:28:33 +0200 Raghavendra Rao Ananta <rananta@google.com>