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author | Linus Torvalds <torvalds@linux-foundation.org> | 2017-05-03 12:45:55 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-05-03 12:45:55 -0700 |
commit | 1684096b1ed813f621fb6cbd06e72235c1c2a0ca (patch) | |
tree | 13a228c35d6344f5d23b2c195aa3b026e42aac4b /Documentation | |
parent | 16a12fa9aed176444fc795b09e796be41902bb08 (diff) | |
parent | 24b43c99647bf9be4995e6a6c9c3a923c147770a (diff) |
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma
Pull rdma updates from Doug Ledford:
"More exchaustive description of primary updates in this release:
- Lots of driver fixes and misc fixes across the board.
- I had to base on a net-next tree because the IPoIB Accelorator
patches needed it.
Unfortunately, it was known to Mellanox that there would need to be
an IPoIB accelorator patch to the net tree (which left some
functions turned off by an #ifdef construct to avoid warnings about
defined but unused functions), then one to the RDMA tree, then a
fixup that went back and re-enabled the functions in the net tree
and enabled their use in the rdma tree
Also, a sparse fix was sent to the net tree after I did my pull,
and the fixup patch conflicts quite directly with that sparse fix,
so I'm going to submit the fixup patch towards the end of the merge
window by itself and based upon your master branch at the time.
- Two separate rounds of hfi1 fixes, one that got dropped from last
release because it came in just a day or two before the end of the
merge window and then the one from this release cycle.
Of note is that I now have a third series that just landed from
Intel yesterday. It is not included in this pull request, but I may
submit it by the end of the week. I'll talk to Intel about
improving the timing of thier submissions for my workflow.
- Changes to our idr usage in the RDMA subsystem that will tie into
our cgroup management and also into the upcoming changes for the
RDMA kernel<->userspace API.
- Addition of support for a netdev to be tied to an RDMA device at
the core level
- Addition of the VNIC driver from Intel.
While IPoIB provides IP over InfiniBand (and *only* IP, no lower
layer protocol headers are allowed or supported), the VNIC driver
presents a virtual Ethernet device with support for things like
varying Ethertypes, VLANs, priorities and other features of
Ethernet.
The virtual devices are centrally managed by the OPA fabric
manager, making this (for the time being) a strictly OPA specific
feature.
- Improvements to the On-Demand Paging support in the RDMA subsystem.
- Addition of three significant OPA changes.
While we added OPA support some time ago (via the hfi1 driver), the
RDMA subsystem has so far glossed over the areas where OPA and
InfiniBand differ.
With this release we are starting to add support for the OPA
extensions into the RDMA core in the following area: Extended port
information for OPA is now supported, extended Address Handle
attributes for OPA are now supported, and extended SA Queries to
get OPA specific subnet information is now supported.
Concise summary from the tag:
- idr usage and locking changes
- build fix for hns
- ipoib debug path record file fix
- hfi1 updates
- core RDMA netdev addition
- Intel VNIC driver addition
- Enhanced accelerators for IPoIB addition
- Debug cleanups in cxgb3/4
- Trivial cleanups from SF Markus Elfring
- Misc rxe fixes from Mellanox
- Misc ipoib fixes from Mellanox
- Lots of mlx4/mlx5 changes from Mellanox
- Misc fixes across the RDMA subsystem
- ODP paging fixes and improvements
- qedr updates
- hfi1 updates
- OPA port info patches
- OPA AH patches
- OPA SA Query patches"
* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma: (191 commits)
infiniband: avoid dereferencing uninitialized dst on error path
IB/SA: Add OPA addr header
IB/mlx5: Add port_xmit_wait to counter registers read
IB/ocrdma: fix out of bounds access to local buffer
IB/mlx4: Fix incorrect order of formal and actual parameters
IB/mlx4: Change flush logic so it adheres to the variable name
mlx5: Fix mlx5_ib_map_mr_sg mr length
IB/rxe: Don't clamp residual length to mtu
IB/SA: Add support to query OPA path records
IB/SA: Add OPA path record type
IB/SA: Split struct sa_path_rec based on IB and ROCE specific fields
IB/SA: Introduce path record specific types
IB/SA: Rename ib_sa_path_rec to sa_path_rec
IB/CM: Add braces when using sizeof
IB/core: Define 'opa' rdma_ah_attr type
IB/core: Define 'ib' and 'roce' rdma_ah_attr types
IB/core: Use rdma_ah_attr accessor functions
IB/core: Add accessor functions for rdma_ah_attr fields
IB/PVRDMA: Rename ib_ah_attr related functions
IB/mthca: Rename to_ib_ah_attr to to_rdma_ah_attr
...
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/infiniband/opa_vnic.txt | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/Documentation/infiniband/opa_vnic.txt b/Documentation/infiniband/opa_vnic.txt new file mode 100644 index 000000000000..282e17be798a --- /dev/null +++ b/Documentation/infiniband/opa_vnic.txt @@ -0,0 +1,153 @@ +Intel Omni-Path (OPA) Virtual Network Interface Controller (VNIC) feature +supports Ethernet functionality over Omni-Path fabric by encapsulating +the Ethernet packets between HFI nodes. + +Architecture +============= +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 | + +------------------------+ +------------------------+ + + +The Omni-Path encapsulated Ethernet packet format is as described below. + +Bits Field +------------------------------------ +Quad Word 0: +0-19 SLID (lower 20 bits) +20-30 Length (in Quad Words) +31 BECN bit +32-51 DLID (lower 20 bits) +52-56 SC (Service Class) +57-59 RC (Routing Control) +60 FECN bit +61-62 L2 (=10, 16B format) +63 LT (=1, Link Transfer Head Flit) + +Quad Word 1: +0-7 L4 type (=0x78 ETHERNET) +8-11 SLID[23:20] +12-15 DLID[23:20] +16-31 PKEY +32-47 Entropy +48-63 Reserved + +Quad Word 2: +0-15 Reserved +16-31 L4 header +32-63 Ethernet Packet + +Quad Words 3 to N-1: +0-63 Ethernet packet (pad extended) + +Quad Word N (last): +0-23 Ethernet packet (pad extended) +24-55 ICRC +56-61 Tail +62-63 LT (=01, Link Transfer Tail Flit) + +Ethernet packet is padded on the transmit side to ensure that the VNIC OPA +packet is quad word aligned. The 'Tail' field contains the number of bytes +padded. On the receive side the 'Tail' field is read and the padding is +removed (along with ICRC, Tail and OPA header) before passing packet up +the network stack. + +The L4 header field contains the virtual Ethernet switch id the VNIC port +belongs to. On the receive side, this field is used to de-multiplex the +received VNIC packets to different VNIC ports. + +Driver Design +============== +Intel OPA VNIC software design is presented in the below diagram. +OPA VNIC functionality has a HW dependent component and a HW +independent component. + +The support has been added for IB device to allocate and free the RDMA +netdev devices. The RDMA netdev supports interfacing with the network +stack thus creating standard network interfaces. OPA_VNIC is an RDMA +netdev device type. + +The HW dependent VNIC functionality is part of the HFI1 driver. It +implements the verbs to allocate and free the OPA_VNIC RDMA netdev. +It involves HW resource allocation/management for VNIC functionality. +It interfaces with the network stack and implements the required +net_device_ops functions. It expects Omni-Path encapsulated Ethernet +packets in the transmit path and provides HW access to them. It strips +the Omni-Path header from the received packets before passing them up +the network stack. It also implements the RDMA netdev control operations. + +The OPA 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 allocates and frees +the OPA_VNIC RDMA netdev devices. It overrides the net_device_ops functions +set by HW dependent VNIC driver where required to accommodate any control +operation. It also handles the encapsulation of Ethernet packets with an +Omni-Path header in the transmit path. For each VNIC interface, the +information required for encapsulation is configured by the EM via VEMA MAD +interface. It also passes any control information to the HW dependent driver +by invoking the RDMA netdev control operations. + + +-------------------+ +----------------------+ + | | | Linux | + | IB MAD | | Network | + | | | Stack | + +-------------------+ +----------------------+ + | | | + | | | + +----------------------------+ | + | | | + | OPA VNIC Module | | + | (OPA VNIC RDMA Netdev | | + | & EMA functions) | | + | | | + +----------------------------+ | + | | + | | + +------------------+ | + | IB core | | + +------------------+ | + | | + | | + +--------------------------------------------+ + | | + | HFI1 Driver with VNIC support | + | | + +--------------------------------------------+ |