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kernel / pub / scm / utils / kernel / ndctl / ndctl / e0d0680bd3e554bd5f211e989480c5a13a023b2d
commite0d0680bd3e554bd5f211e989480c5a13a023b2d[log] [tgz]
authorVishal Verma <vishal.l.verma@intel.com>Tue Mar 05 23:24:42 2024 -0700
committerVishal Verma <vishal.l.verma@intel.com>Tue Mar 05 23:24:42 2024 -0700
tree5f95a0b2e6c1921f0e8954c4b7171a7c912cc7fb
parent731ca1f75a5f421249baef4f850b477e9867a00d [diff]
parent5e9157d6721a878757f0fe8a3c51f06f9e94934a [diff]
Merge branch 'for-79/qos-class' into pending

Starting in v6.8, the kernel exports a qos_class token for the root
decoders (CFMWS) and as well as for the CXL memory devices. The
qos_class exported for a device is calculated by the driver during
device probe.  Currently a qos_class is exported for the volatile
partition (ram) and another for the persistent partition (pmem).  In the
future qos_class will be exported for DCD regions. Display of qos_class
is through the CXL CLI list command with -vvv for extra verbose.

A qos_class check as also been added for region creation. A warning is
emitted when the qos_class of a memory range of a CXL memory device
being included in the CXL region assembly does not match the qos_class
of the root decoder. Options are available to suppress the warning or to
fail the region creation. This enabling provides a guidance on flagging
memory ranges being used is not optimal for performance for the CXL
region to be formed.
tree: 5f95a0b2e6c1921f0e8954c4b7171a7c912cc7fb
  1. ccan/
  2. contrib/
  3. cxl/
  4. daxctl/
  5. Documentation/
  6. LICENSES/
  7. ndctl/
  8. rhel/
  9. scripts/
  10. sles/
  11. test/
  12. tools/
  13. util/
  14. .clang-format
  15. .gitignore
  16. acpi.h
  17. clean_config.sh
  18. config.h.meson
  19. CONTRIBUTING.md
  20. COPYING
  21. git-version
  22. git-version-gen
  23. make-git-snapshot.sh
  24. meson.build
  25. meson_options.txt
  26. ndctl.spec.in
  27. README.md
  28. rpmbuild.sh
  29. test.h
  30. version.h.in
README.md

ndctl

Utility library for managing the libnvdimm (non-volatile memory device) sub-system in the Linux kernel

Build

meson setup build;
meson compile -C build;

Optionally, to install:

meson install -C build

There are a number of packages required for the build steps that may not be installed by default. For information about the required packages, see the “BuildRequires:” lines in ndctl.spec.in.

https://github.com/pmem/ndctl/blob/main/ndctl.spec.in

Documentation

See the latest documentation for the NVDIMM kernel sub-system here:

https://www.kernel.org/doc/html/latest/driver-api/nvdimm/index.html

A getting started guide is also available on the kernel.org nvdimm wiki:

https://nvdimm.wiki.kernel.org/start

Unit Tests

The unit tests run by meson test require the nfit_test.ko module to be loaded. To build and install nfit_test.ko:

  1. Obtain the kernel source. For example,
    git clone -b libnvdimm-for-next git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm.git

  2. Skip to step 3 if the kernel version is >= v4.8. Otherwise, for kernel versions < v4.8, configure the kernel to make some memory available to CMA (contiguous memory allocator). This will be used to emulate DAX.

    CONFIG_DMA_CMA=y
CONFIG_CMA_SIZE_MBYTES=200

    or
    cma=200M on the kernel command line.

  3. Compile the libnvdimm sub-system as a module, make sure “zone device” memory is enabled, and enable the btt, pfn, and dax features of the sub-system:

    CONFIG_X86_PMEM_LEGACY=m
CONFIG_ZONE_DEVICE=y
CONFIG_LIBNVDIMM=m
CONFIG_BLK_DEV_PMEM=m
CONFIG_BTT=y
CONFIG_NVDIMM_PFN=y
CONFIG_NVDIMM_DAX=y
CONFIG_DEV_DAX_PMEM=m
CONFIG_ENCRYPTED_KEYS=y
CONFIG_NVDIMM_SECURITY_TEST=y
CONFIG_STRICT_DEVMEM=y
CONFIG_IO_STRICT_DEVMEM=y

  4. Build and install the unit test enabled libnvdimm modules in the following order. The unit test modules need to be in place prior to the depmod that runs during the final modules_install

    make M=tools/testing/nvdimm
sudo make M=tools/testing/nvdimm modules_install
sudo make modules_install

  5. CXL test

    The unit tests will also run CXL tests by default. In order to make these work, we need to install the cxl_test.ko as well.

    Obtain the CXL kernel source(optional). For example, git clone -b pending git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl.git

    Enable CXL-related kernel configuration options.

    CONFIG_CXL_BUS=m
CONFIG_CXL_PCI=m
CONFIG_CXL_ACPI=m
CONFIG_CXL_PMEM=m
CONFIG_CXL_MEM=m
CONFIG_CXL_PORT=m
CONFIG_CXL_REGION=y
CONFIG_CXL_REGION_INVALIDATION_TEST=y
CONFIG_DEV_DAX_CXL=m

  6. Install cxl_test and related mock modules.

    make M=tools/testing/cxl
sudo make M=tools/testing/cxl modules_install
sudo make modules_install

  7. Now run meson test -C build in the ndctl source directory, or ndctl test, if ndctl was built with -Dtest=enabled as a configuration option to meson.

  8. To run the ‘destructive’ set of tests that may clobber existing pmem configurations and data, configure meson with the destructive option after the meson setup step:

    meson configure -Dtest=enabled -Ddestructive=enabled build;

Troubleshooting

The unit tests will validate that the environment is set up correctly before they try to run. If the platform is misconfigured, i.e. the unit test modules are not available, or the test versions of the modules are superseded by the “in-tree/production” version of the modules meson test will skip tests and report a message like the following in build/meson-logs/testlog.txt

SKIP: libndctl
==============
test/init: nfit_test_init: nfit.ko: appears to be production version: /lib/modules/4.8.8-200.fc24.x86_64/kernel/drivers/acpi/nfit/nfit.ko.xz
__ndctl_test_skip: explicit skip test_libndctl:2684
nfit_test unavailable skipping tests

If the unit test modules are indeed available in the modules ‘extra’ directory the default depmod policy can be overridden by adding a file to /etc/depmod.d with the following contents:

override nfit * extra
override device_dax * extra
override dax_pmem * extra
override dax_pmem_core * extra
override dax_pmem_compat * extra
override libnvdimm * extra
override nd_btt * extra
override nd_e820 * extra
override nd_pmem * extra

The nfit_test module emulates pmem with memory allocated via vmalloc(). One of the side effects is that this breaks ‘physically contiguous’ assumptions in the driver. Use the '--align=4K option to ‘ndctl create-namespace’ to avoid these corner case scenarios.