[v4,1/2] doc: clarify instructions on running as non-root
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Commit Message
The current instructions are slightly out of date when it comes to
providing information about setting up the system for using DPDK as
non-root, so update them.
Cc: stable@dpdk.org
Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
---
Notes:
v2:
- Moved VFIO description to be first
doc/guides/linux_gsg/enable_func.rst | 58 ++++++++++++++++++++--------
1 file changed, 41 insertions(+), 17 deletions(-)
@@ -60,22 +60,51 @@ The application can then determine what action to take, if any, if the HPET is n
if any, and on what is available on the system at runtime.
Running DPDK Applications Without Root Privileges
---------------------------------------------------------
+-------------------------------------------------
+
+In order to run DPDK as non-root, the following Linux filesystem objects'
+permissions should be adjusted to ensure that the Linux account being used to
+run the DPDK application has access to them:
+
+* All directories which serve as hugepage mount points, for example, ``/dev/hugepages``
+
+* If the HPET is to be used, ``/dev/hpet``
+
+When running as non-root user, there may be some additional resource limits
+that are imposed by the system. Specifically, the following resource limits may
+need to be adjusted in order to ensure normal DPDK operation:
+
+* RLIMIT_LOCKS (number of file locks that can be held by a process)
+
+* RLIMIT_NOFILE (number of open file descriptors that can be held open by a process)
+
+* RLIMIT_MEMLOCK (amount of pinned pages the process is allowed to have)
+
+The above limits can usually be adjusted by editing
+``/etc/security/limits.conf`` file, and rebooting.
+
+Additionally, depending on which kernel driver is in use, the relevant
+resources also should be accessible by the user running the DPDK application.
+
+For ``vfio-pci`` kernel driver, the following Linux file system objects'
+permissions should be adjusted:
+
+* The VFIO device file, ``/dev/vfio/vfio``
+
+* The directories under ``/dev/vfio`` that correspond to IOMMU group numbers of
+ devices intended to be used by DPDK, for example, ``/dev/vfio/50``
.. note::
- The instructions below will allow running DPDK as non-root with older
- Linux kernel versions. However, since version 4.0, the kernel does not allow
- unprivileged processes to read the physical address information from
- the pagemaps file, making it impossible for those processes to use HW
- devices which require physical addresses
+ The instructions below will allow running DPDK with ``igb_uio`` or
+ ``uio_pci_generic`` drivers as non-root with older Linux kernel versions.
+ However, since version 4.0, the kernel does not allow unprivileged processes
+ to read the physical address information from the pagemaps file, making it
+ impossible for those processes to be used by non-privileged users. In such
+ cases, using the VFIO driver is recommended.
-Although applications using the DPDK use network ports and other hardware resources directly,
-with a number of small permission adjustments it is possible to run these applications as a user other than "root".
-To do so, the ownership, or permissions, on the following Linux file system objects should be adjusted to ensure that
-the Linux user account being used to run the DPDK application has access to them:
-
-* All directories which serve as hugepage mount points, for example, ``/mnt/huge``
+For ``igb_uio`` or ``uio_pci_generic`` kernel drivers, the following Linux file
+system objects' permissions should be adjusted:
* The userspace-io device files in ``/dev``, for example, ``/dev/uio0``, ``/dev/uio1``, and so on
@@ -84,11 +113,6 @@ the Linux user account being used to run the DPDK application has access to them
/sys/class/uio/uio0/device/config
/sys/class/uio/uio0/device/resource*
-* If the HPET is to be used, ``/dev/hpet``
-
-.. note::
-
- On some Linux installations, ``/dev/hugepages`` is also a hugepage mount point created by default.
Power Management and Power Saving Functionality
-----------------------------------------------