Add HFI VNIC design document explaining the VNIC architecture and the driver design.
Reviewed-by: Dennis Dalessandro <dennis.dalessan...@intel.com> Reviewed-by: Ira Weiny <ira.we...@intel.com> Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathap...@intel.com> --- Documentation/infiniband/hfi_vnic.txt | 95 +++++++++++++++++++++++++++++++++++ 1 file changed, 95 insertions(+) create mode 100644 Documentation/infiniband/hfi_vnic.txt diff --git a/Documentation/infiniband/hfi_vnic.txt b/Documentation/infiniband/hfi_vnic.txt new file mode 100644 index 0000000..1f39d8b --- /dev/null +++ b/Documentation/infiniband/hfi_vnic.txt @@ -0,0 +1,95 @@ +Intel Omni-Path Host Fabric Interface (HFI) Virtual Network Interface +Controller (VNIC) feature supports Ethernet functionality over Omni-Path +fabric by encapsulating the Ethernet packets between HFI nodes. + +The patterns of exchanges of Omni-Path encapsulated Ethernet packets +involves one or more virtual Ethernet switches overlaid on the Omni-Path +fabric topology. A subset of HFI nodes on the Omni-Path fabric are +permitted to exchange encapsulated Ethernet packets across a particular +virtual Ethernet switch. The virtual Ethernet switches are logical +abstractions achieved by configuring the HFI nodes on the fabric for +header generation and processing. In the simplest configuration all HFI +nodes across the fabric exchange encapsulated Ethernet packets over a +single virtual Ethernet switch. A virtual Ethernet switch, is effectively +an independent Ethernet network. The configuration is performed by an +Ethernet Manager (EM) which is part of the trusted Fabric Manager (FM) +application. HFI nodes can have multiple VNICs each connected to a +different virtual Ethernet switch. The below diagram presents a case +of two virtual Ethernet switches with two HFI nodes. + + +-------------------+ + | Subnet/ | + | Ethernet | + | Manager | + +-------------------+ + / / + / / + / / + / / ++-----------------------------+ +------------------------------+ +| Virtual Ethernet Switch | | Virtual Ethernet Switch | +| +---------+ +---------+ | | +---------+ +---------+ | +| | VPORT | | VPORT | | | | VPORT | | VPORT | | ++--+---------+----+---------+-+ +-+---------+----+---------+---+ + | \ / | + | \ / | + | \/ | + | / \ | + | / \ | + +-----------+------------+ +-----------+------------+ + | VNIC | VNIC | | VNIC | VNIC | + +-----------+------------+ +-----------+------------+ + | HFI | | HFI | + +------------------------+ +------------------------+ + +Intel HFI VNIC software design is presented in the below diagram. +HFI VNIC functionality has a HW dependent component and a HW +independent component. + +The HW dependent VNIC functionality is part of the HFI1 driver. It +implements the callback functions to do various tasks which includes +adding and removing of VNIC ports, HW resource allocation for VNIC +functionality and actual transmission and reception of encapsulated +Ethernet packets over the fabric. Each VNIC port is addressed by the +HFI port number, and the VNIC port number on that HFI port. + +The HFI VNIC module implements the HW independent VNIC functionality. +It consists of two parts. The VNIC Ethernet Management Agent (VEMA) +registers itself with IB core as an IB client and interfaces with the +IB MAD stack. It exchanges the management information with the Ethernet +Manager (EM) and the VNIC netdev. The VNIC netdev part interfaces with +the Linux network stack, thus providing standard Ethernet network +interfaces. It invokes HFI device's VNIC callback functions for HW access. +The VNIC netdev encapsulates the Ethernet packets with an Omni-Path +header before passing them to the HFI1 driver for transmission. +Similarly, it de-encapsulates the received Omni-Path packets before +passing them to the network stack. For each VNIC interface, the +information required for encapsulation is configured by EM via VEMA MAD +interface. + + + +-------------------+ +----------------------+ + | | | Linux | + | IB MAD | | Network | + | | | Stack | + +-------------------+ +----------------------+ + | | + | | + +--------------------------------------------+ + | | + | HFI VNIC Module | + | (HFI VNIC Netdev and EMA drivers) | + | | + +--------------------------------------------+ + | + | + +------------------+ + | IB core | + +------------------+ + | + | + +--------------------------------------------+ + | | + | HFI1 Driver with VNIC support | + | | + +--------------------------------------------+ -- 1.8.3.1
