[PATCH net-next v6 00/10] enic: SR-IOV V2 admin channel and MBOX protocol

[Satish Kharat]

This series adds the admin channel infrastructure and mailbox (MBOX)
protocol needed for V2 SR-IOV support in the enic driver.

The V2 SR-IOV design uses a direct PF-VF communication channel built on
dedicated WQ/RQ/CQ hardware resources and an MSI-X interrupt.

Firmware capability and admin channel infrastructure (patches 1-4):
  - Probe-time firmware feature check for V2 SR-IOV support
  - Admin channel open/close, RQ buffer management, CQ service
    with MSI-X interrupt and NAPI polling

MBOX protocol and VF enable (patches 5-10):
  - MBOX message types, core send/receive, PF and VF handlers
  - V2 SR-IOV enable wiring with admin channel setup
  - V2 VF probe with admin channel and PF registration

Signed-off-by: Satish Kharat <satishkh@xxxxxxxxx>
---
Changes in v6:
- Add explanatory comments documenting admin_cq[0] (WQ CQE size) and
  admin_cq[1] (RQ CQE size matching firmware enic_ext_cq() programming)
  allocations (patch 2)
- Enforce bytes_written from CQ descriptor when enqueuing admin RQ
  message; previously buf->len (allocation size) was passed, exposing
  uninitialized buffer memory beyond the real payload (patch 4)
- Drop admin RQ messages with TRUNCATED set or FCS_OK clear, gated by
  netdev_warn_once() (patch 4)
- Disable interrupt_enable on admin_cq[0]: WQ completions are polled
  synchronously inside enic_mbox_send_msg() and never raise an
  interrupt; matches admin_cq[1] (RQ) which does NAPI polling (patch 4)
- Add mbox_expected_reply gating in VF reply handlers (capability,
  register, unregister): drop replies whose type does not match the
  current waiter's expected type, avoiding spurious wakeup of an
  unrelated waiter from a stale reply that arrives after timeout
  (patch 8)
- Distinguish error returns in enic_mbox_vf_unregister(): -ETIMEDOUT
  (no reply received), -EACCES (PF rejected the unregister), 0 on
  success.  Previously all paths collapsed to a single -ETIMEDOUT
  (patch 8)
- Reserve one extra MSI-X slot in enic_set_intr_mode() when
  has_admin_channel is set so enic_admin_setup_intr() always has room
  to allocate at intr_count without exceeding intr_avail bounds when
  data queue count is maxed out (patch 10)
- Clarify in commit messages that .sriov_configure is intentionally
  not yet wired in this series and will be added in a follow-up after
  the necessary devcmd hardening lands (patch 9)
- Link to v5: https://patch.msgid.link/20260423-enic-sriov-v2-admin-channel-v2-v5-0-caa9f504a3dc@xxxxxxxxx

Changes in v5:
- Fix DMA-into-freed-memory race: call enic_admin_qp_type_set() before
  disabling RQ/WQ in both error and close paths (patch 3)
- Fix DMA mapping leak: enic_admin_wq_buf_clean() now unmaps and frees
  WQ buffers still held at close time after a send timeout (patch 3)
- Log rate-limited warning on admin RQ refill failure (patch 4)
- Add missing linux/types.h and linux/bits.h includes to enic_mbox.h
  (patch 5)
- Guard mbox_lock/mbox_comp init with mbox_initialized flag to prevent
  re-initialization on sriov_configure re-entry (patch 7)
- Clear VF registered state before sending unregister reply so PF does
  not treat a dead VF as still registered (patch 8)
- Gate VF-facing log messages with net_ratelimit() to prevent malicious
  VF from flooding PF dmesg (patch 8)
- Reject VF port profile requests when V2 SR-IOV is active since
  enic->pp is not reallocated for V2 VFs (patch 9)
- Move enic_sriov_detect_vf_type() before auto-enable check; skip
  probe-time auto-enable for V2 VFs (patch 9)
- Move admin channel close and VF unregister before unregister_netdev()
  in enic_remove() to prevent use-after-free on netdev (patch 10)
- Add comment in enic_reset() documenting that admin channel is not
  recovered after soft reset (patch 10)
- Bypass RES_TYPE_SRIOV_INTR check for V2 VFs in admin channel
  capability detection (patch 10)
- Link to v4: https://patch.msgid.link/20260411-enic-sriov-v2-admin-channel-v2-v4-0-f052326c2a57@xxxxxxxxx

Changes in v4:
- Fix reverse xmas tree variable ordering (patches 1, 6)
- Use kzalloc_obj instead of kzalloc with sizeof (patch 9)
- Add NULL check for pp allocation in V1 SR-IOV disable path (patch 9)
- Link to v3: https://lore.kernel.org/r/20260408-enic-sriov-v2-admin-channel-v2-v3-0-1d4999a03cec@xxxxxxxxx

Changes in v3:
- Use early-return pattern in enic_sriov_detect_vf_type to reduce
  nesting (patch 1) [Breno Leitao]
- Link to v2: https://lore.kernel.org/r/20260408-enic-sriov-v2-admin-channel-v2-v2-0-d05dd3623fd3@xxxxxxxxx

Changes in v2:
- Fix lines exceeding 80 columns (patches 4, 6, 7, 8)
- Add __maybe_unused to enic_sriov_configure and enic_sriov_v2_enable;
  .sriov_configure wiring deferred to a later series after devcmd
  hardening is in place (patch 9)
- Guard probe-time auto-enable to skip V2 VFs (patch 9)
- Link to v1: https://lore.kernel.org/r/20260406-enic-sriov-v2-admin-channel-v2-v1-0-82cc47636a78@xxxxxxxxx

To: Satish Kharat <satishkh@xxxxxxxxx>
To: Andrew Lunn <andrew+netdev@xxxxxxx>
To: "David S. Miller" <davem@xxxxxxxxxxxxx>
To: Eric Dumazet <edumazet@xxxxxxxxxx>
To: Jakub Kicinski <kuba@xxxxxxxxxx>
To: Paolo Abeni <pabeni@xxxxxxxxxx>
Cc: netdev@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: Sesidhar Baddela <sebaddel@xxxxxxxxx>

---
Satish Kharat (10):
      enic: verify firmware supports V2 SR-IOV at probe time
      enic: add admin channel open and close for SR-IOV
      enic: add admin RQ buffer management
      enic: add admin CQ service with MSI-X interrupt and NAPI polling
      enic: define MBOX message types and header structures
      enic: add MBOX core send and receive for admin channel
      enic: add MBOX PF handlers for VF register and capability
      enic: add MBOX VF handlers for capability, register and link state
      enic: wire V2 SR-IOV enable with admin channel and MBOX
      enic: add V2 VF probe with admin channel and PF registration

 drivers/net/ethernet/cisco/enic/Makefile      |   3 +-
 drivers/net/ethernet/cisco/enic/enic.h        |  38 +-
 drivers/net/ethernet/cisco/enic/enic_admin.c  | 588 +++++++++++++++++++++++++
 drivers/net/ethernet/cisco/enic/enic_admin.h  |  27 ++
 drivers/net/ethernet/cisco/enic/enic_main.c   | 255 ++++++++++-
 drivers/net/ethernet/cisco/enic/enic_mbox.c   | 605 ++++++++++++++++++++++++++
 drivers/net/ethernet/cisco/enic/enic_mbox.h   |  95 ++++
 drivers/net/ethernet/cisco/enic/enic_pp.c     |   5 +
 drivers/net/ethernet/cisco/enic/enic_res.c    |   4 +-
 drivers/net/ethernet/cisco/enic/vnic_devcmd.h |  11 +
 drivers/net/ethernet/cisco/enic/vnic_enet.h   |   4 +-
 11 files changed, 1617 insertions(+), 18 deletions(-)
---
base-commit: 09942ddedcb960f9e78fd817ec33f501d1040c5b
change-id: 20260404-enic-sriov-v2-admin-channel-v2-c0aa3e988833

Best regards,
--  
Satish Kharat <satishkh@xxxxxxxxx>