net: mana: Per-vPort EQ and MSI-X interrupt management [LWN.net]

From:		Long Li <longli-AT-microsoft.com>
To:		Long Li <longli-AT-microsoft.com>, Konstantin Taranov <kotaranov-AT-microsoft.com>, Jakub Kicinski <kuba-AT-kernel.org>, "David S . Miller" <davem-AT-davemloft.net>, Paolo Abeni <pabeni-AT-redhat.com>, Eric Dumazet <edumazet-AT-google.com>, Andrew Lunn <andrew+netdev-AT-lunn.ch>, Jason Gunthorpe <jgg-AT-ziepe.ca>, Leon Romanovsky <leon-AT-kernel.org>, Haiyang Zhang <haiyangz-AT-microsoft.com>, "K . Y . Srinivasan" <kys-AT-microsoft.com>, Wei Liu <wei.liu-AT-kernel.org>, Dexuan Cui <decui-AT-microsoft.com>
Subject:		[PATCH net-next v4 0/6] net: mana: Per-vPort EQ and MSI-X interrupt management
Date:		Fri, 20 Mar 2026 16:54:13 -0700
Message-ID:		<cover.1774049761.git.longli@microsoft.com>
Cc:		Simon Horman <horms-AT-kernel.org>, netdev-AT-vger.kernel.org, linux-rdma-AT-vger.kernel.org, linux-hyperv-AT-vger.kernel.org, linux-kernel-AT-vger.kernel.org
Archive-link:		Article

This series adds per-vPort Event Queue (EQ) allocation and MSI-X interrupt
management for the MANA driver. Previously, all vPorts shared a single set
of EQs. This change enables dedicated EQs per vPort with support for both
dedicated and shared MSI-X vector allocation modes.

Patch 1 moves EQ ownership from mana_context to per-vPort mana_port_context
and exports create/destroy functions for the RDMA driver.

Patch 2 adds device capability queries to determine whether MSI-X vectors
should be dedicated per-vPort or shared. When the number of available MSI-X
vectors is insufficient for dedicated allocation, the driver enables sharing
mode with bitmap-based vector assignment.

Patch 3 introduces the GIC (GDMA IRQ Context) abstraction with reference
counting, allowing multiple EQs to safely share a single MSI-X vector.

Patch 4 converts the global EQ allocation in probe/resume to use the new
GIC functions.

Patch 5 adds per-vPort GIC lifecycle management, calling get/put on each
EQ creation and destruction during vPort open/close.

Patch 6 extends the same GIC lifecycle management to the RDMA driver's EQ
allocation path.

Changes in v4:
- Rebased on net-next/main 7.0-rc4
- Patch 2: Use MANA_DEF_NUM_QUEUES instead of hardcoded 16 for
  max_num_queues clamping
- Patch 3: Track dyn_msix in GIC context instead of re-checking
  pci_msix_can_alloc_dyn() on each call; improved remove_irqs iteration
  to skip unallocated entries

Changes in v3:
- Rebased on net-next/main
- Patch 1: Added NULL check for mpc->eqs in mana_ib_create_qp_rss() to
  prevent NULL pointer dereference when RSS QP is created before a raw QP
  has configured the vport and allocated EQs

Changes in v2:
- Rebased on net-next/main (adapted to kzalloc_objs/kzalloc_obj macros,
  new GDMA_DRV_CAP_FLAG definitions)
- Patch 2: Fixed misleading comment for max_num_queues vs
  max_num_queues_vport in gdma.h
- Patch 3: Fixed spelling typo in gdma_main.c ("difference" -> "different")

Long Li (6):
  net: mana: Create separate EQs for each vPort
  net: mana: Query device capabilities and configure MSI-X sharing for
    EQs
  net: mana: Introduce GIC context with refcounting for interrupt
    management
  net: mana: Use GIC functions to allocate global EQs
  net: mana: Allocate interrupt context for each EQ when creating vPort
  RDMA/mana_ib: Allocate interrupt contexts on EQs

 drivers/infiniband/hw/mana/main.c             |  47 ++-
 drivers/infiniband/hw/mana/qp.c               |  16 +-
 .../net/ethernet/microsoft/mana/gdma_main.c   | 307 +++++++++++++-----
 drivers/net/ethernet/microsoft/mana/mana_en.c | 162 +++++----
 include/net/mana/gdma.h                       |  32 +-
 include/net/mana/mana.h                       |   7 +-
 6 files changed, 416 insertions(+), 155 deletions(-)

-- 
2.43.0