[PATCH v3 0/7] cxl: Background cmds and device sanitation

[Davidlohr Bueso <dave@stgolabs.net>]

Hello,

This series adds support for the rest of the security related cxl operations
which are not strictly dependent on PMEM.

Patch 1 adds the required background cmd handling bits (polling and irq).
This is really the main motivation of the series as there are various
features that will need this regardless of sanitation.

Patch 2 adds a new sysfs 'security/state' file, which shows "disabled" if
no security features are available - which is more intuitive than no showing
it.

Patch 3 adds a way to check if the device is actively used by tracking regions
with target the memdevice to sanitize. I realize this might not be what is
desired and wanted to get the expectations for this. This is more of a RFC
patch.

Patches 4-7 add the Sanitation and Secure Erase support, per CXL3.0 specs.

These changes have been tested with both the mock device as well as with qemu[0,1].

Changes from v2 (https://lore.kernel.org/linux-cxl/20221206011501.464916-1-dave@stgolabs.net/):
- Redid the bacground cmd handling to use a syncronous approach instead.
- Added cxl_memdev_active_region() to check if the memdevice is being used
  (actively decoding any HPA ranges).
- Create a new security sysfs directory with a 'state' file which is always visible.
- The sysfs files' to trigger the security commands is only visible if
  cpu_cache_has_invalidate_memregion().
- Added a sanitize test for the mock device.

Please consider for v6.4.

Thanks!

[0]: https://github.com/davidlohr/qemu/commit/64a93a5b824b59d3b547f06f7fbb1269fb4790ce
[1]: https://lore.kernel.org/linux-cxl/20230224194443.1990440-1-dave@stgolabs.net

Davidlohr Bueso (7):
  cxl/mbox: Add background cmd handling machinery
  cxl/security: Add security state sysfs ABI
  cxl/region: Add cxl_memdev_active_region()
  cxl/mem: Support Sanitation
  cxl/test: Add "Sanitize" opcode support
  cxl/mem: Support Secure Erase
  cxl/test: Add "Secure Erase" opcode support

 Documentation/ABI/testing/sysfs-bus-cxl |  34 +++++++
 drivers/cxl/core/mbox.c                 | 117 +++++++++++++++++++++++
 drivers/cxl/core/memdev.c               | 119 ++++++++++++++++++++++++
 drivers/cxl/core/region.c               |  33 ++++++-
 drivers/cxl/cxl.h                       |  13 +++
 drivers/cxl/cxlmem.h                    |  14 +++
 drivers/cxl/pci.c                       | 100 +++++++++++++++++++-
 tools/testing/cxl/test/mem.c            |  52 +++++++++++
 8 files changed, 476 insertions(+), 6 deletions(-)

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2.39.2