[PATCH v5 0/6] net/gve: add hardware timestamping support

[Mark Blasko <blasko@google.com>]

This patch series introduces support for GVE hardware timestamping
on DQO queues. To support concurrent access, a mutex lock is introduced
to protect admin queue operations. A mechanism is then added to
periodically synchronize the NIC clock via a dedicated control thread,
and support is introduced for the read_clock ethdev operation.
Finally, the RX datapath is updated to reconstruct full 64-bit
timestamps from the 32-bit values in DQO descriptors.

---
v5:
- Patch 4: Reword commit message to describe control thread implementation.

v4:
- Patch 4: Offload periodic NIC clock reads to a dedicated control thread.
- Patch 5: Correct mutex initialization and teardown ordering.
- Patch 6: Update GVE documentation to clarify queue format requirements.

v3:
- Patch 5:
  - Add mutex lock to protect shared NIC timestamp memzone access.
  - Fix missing read_clock assignment to DQO queue ops table
    (accidental omission in v2).

v2:
- Patch 1: Dropped ROBUST mutex attribute.
- Patch 3: Added adminq timestamp counter reset to gve_adminq_alloc.
- Patch 4:
  - Removed redundant void* casts.
  - Handled alarm reschedule failures by marking timestamp stale.
  - Added transient error logging on memzone allocation failure.
- Patch 5: Scoped read_clock ethdev operation strictly to DQO queues.
- Patch 6:
  - Scoped timestamp offload capability advertisement strictly to
    DQO queues.
  - Predicated capability advertisement directly on memzone
    allocation.
  - Initialized mbuf_timestamp_offset to -1.
  - Added blank line separating release notes.
---

Mark Blasko (6):
  net/gve: add thread safety to admin queue
  net/gve: add device option support for HW timestamps
  net/gve: add AdminQ command for NIC timestamps
  net/gve: add periodic NIC clock synchronization
  net/gve: support read clock ethdev op
  net/gve: reconstruct HW timestamps from DQO

 .mailmap                               |   1 +
 doc/guides/nics/features/gve.ini       |   1 +
 doc/guides/nics/gve.rst                |  20 +++
 doc/guides/rel_notes/release_26_07.rst |   4 +
 drivers/net/gve/base/gve_adminq.c      | 128 +++++++++++++---
 drivers/net/gve/base/gve_adminq.h      |  29 ++++
 drivers/net/gve/base/gve_desc_dqo.h    |   8 +-
 drivers/net/gve/gve_ethdev.c           | 194 +++++++++++++++++++++++--
 drivers/net/gve/gve_ethdev.h           |  43 ++++++
 drivers/net/gve/gve_rx_dqo.c           |  26 ++++
 10 files changed, 424 insertions(+), 30 deletions(-)

-- 
2.54.0.1189.g8c84645362-goog