[PATCH v3 0/6] mshv: Debugfs interface for mshv_root

[Nuno Das Neves <nunodasneves@linux.microsoft.com>]

Expose hypervisor, logical processor, partition, and virtual processor
statistics via debugfs. These are provided by mapping 'stats' pages via
hypercall.

Patch #1: Update hv_call_map_stats_page() to return success when
          HV_STATS_AREA_PARENT is unavailable, which is the case on some
          hypervisor versions, where it can fall back to HV_STATS_AREA_SELF
Patch #2: Use struct hv_stats_page pointers instead of void *
Patch #3: Make mshv_vp_stats_map/unmap() more flexible to use with debugfs code
Patch #4: Always map vp stats page regardless of scheduler, to reuse in debugfs
Patch #5: Introduce the definitions needed for the various stats pages
Patch #6: Add mshv_debugfs.c, and integrate it with the mshv_root driver to
          expose the partition and VP stats.

---
Changes in v3:
- Add 3 small refactor/cleanup patches (patches 2,3,4) from Stanislav. These
  simplify some of the debugfs code, and fix issues with mapping VP stats on
  L1VH.
- Fix cleanup of parent stats dentries on module removal (via squashing some
  internal patches into patch #6) [Praveen]
- Remove unused goto label [Stanislav, kernel bot]
- Use struct hv_stats_page * instead of void * in mshv_debugfs.c [Stanislav]
- Remove some redundant variables [Stanislav]
- Rename debugfs dentry fields for brevity [Stanislav]
- Use ERR_CAST() for the dentry error pointer returned from
  lp_debugfs_stats_create() [Stanislav]
- Fix leak of pages allocated for lp stats mappings by storing them in an array
  [Michael]
- Add comments to clarify PARENT vs SELF usage and edge cases [Michael]
- Add VpLoadAvg for x86 and print the stat [Michael]
- Add NUM_STATS_AREAS for array sizing in mshv_debugfs.c [Michael]

Changes in v2:
- Remove unnecessary pr_debug_once() in patch 1 [Stanislav Kinsburskii]
- CONFIG_X86 -> CONFIG_X86_64 in patch 2 [Stanislav Kinsburskii]

---
Nuno Das Neves (2):
  mshv: Add definitions for stats pages
  mshv: Add debugfs to view hypervisor statistics

Purna Pavan Chandra Aekkaladevi (1):
  mshv: Ignore second stats page map result failure

Stanislav Kinsburskii (3):
  mshv: Use typed hv_stats_page pointers
  mshv: Improve mshv_vp_stats_map/unmap(), add them to mshv_root.h
  mshv: Always map child vp stats pages regardless of scheduler type

 drivers/hv/Makefile            |    1 +
 drivers/hv/mshv_debugfs.c      | 1103 ++++++++++++++++++++++++++++++++
 drivers/hv/mshv_root.h         |   49 +-
 drivers/hv/mshv_root_hv_call.c |   64 +-
 drivers/hv/mshv_root_main.c    |  130 ++--
 include/hyperv/hvhdk.h         |  437 +++++++++++++
 6 files changed, 1721 insertions(+), 63 deletions(-)
 create mode 100644 drivers/hv/mshv_debugfs.c

-- 
2.34.1