[PATCH v2 net-next 00/21] nvme-tcp receive offloads

[PATCH v2 net-next 00/21] nvme-tcp receive offloads

[Boris Pismenny]

Changes since v1:
=========================================
* Rework iov_iter copy skip if src==dst to be less intrusive (David Ahern)
* Add tcp-ddp documentation (David Ahern)
* Refactor mellanox driver patches into more patches (Saeed Mahameed)
* Avoid pointer casting (David Ahern)
* Rename nvme-tcp offload flags (Shai Malin)
* Update cover-letter according to the above

Changes since RFC v1:
=========================================
* Split mlx5 driver patches to several commits
* Fix nvme-tcp handling of recovery flows. In particular, move queue offlaod
  init/teardown to the start/stop functions.

Overview
=========================================
This series adds support for nvme-tcp receive offloads
which do not mandate the offload of the network stack to the device.
Instead, these work together with TCP to offload:
1. copy from SKB to the block layer buffers
2. CRC verification for received PDU

The series implements these as a generic offload infrastructure for storage
protocols, which we call TCP Direct Data Placement (TCP_DDP) and TCP DDP CRC,
respectively. We use this infrastructure to implement NVMe-TCP offload for copy
and CRC. Future implementations can reuse the same infrastructure for other
protcols such as iSCSI.

Note:
These offloads are similar in nature to the packet-based NIC TLS offloads,
which are already upstream (see net/tls/tls_device.c).
You can read more about TLS offload here:
https://www.kernel.org/doc/html/latest/networking/tls-offload.html

Initialization and teardown:
=========================================
The offload for IO queues is initialized after the handshake of the
NVMe-TCP protocol is finished by calling `nvme_tcp_offload_socket`
with the tcp socket of the nvme_tcp_queue:
This operation sets all relevant hardware contexts in
hardware. If it fails, then the IO queue proceeds as usually with no offload.
If it succeeds then `nvme_tcp_setup_ddp` and `nvme_tcp_teardown_ddp` may be
called to perform copy offload, and crc offload will be used.
This initialization does not change the normal operation of nvme-tcp in any
way besides adding the option to call the above mentioned NDO operations.

For the admin queue, nvme-tcp does not initialize the offload.
Instead, nvme-tcp calls the driver to configure limits for the controller,
such as max_hw_sectors and max_segments; these must be limited to accomodate
potential HW resource limits, and to improve performance.

If some error occured, and the IO queue must be closed or reconnected, then
offload is teardown and initialized again. Additionally, we handle netdev
down events via the existing error recovery flow.

Copy offload works as follows:
=========================================
The nvme-tcp layer calls the NIC drive to map block layer buffers to ccid using
`nvme_tcp_setup_ddp` before sending the read request. When the repsonse is
received, then the NIC HW will write the PDU payload directly into the
designated buffer, and build an SKB such that it points into the destination
buffer; this SKB represents the entire packet received on the wire, but it
points to the block layer buffers. Once nvme-tcp attempts to copy data from
this SKB to the block layer buffer it can skip the copy by checking in the
copying function (memcpy_to_page):
if (src == dst) -> skip copy
Finally, when the PDU has been processed to completion, the nvme-tcp layer
releases the NIC HW context be calling `nvme_tcp_teardown_ddp` which
asynchronously unmaps the buffers from NIC HW.

As the copy skip change is in a sensative function, we are careful to avoid
changing it. To that end, we create alternative skb copy and hash iterators
that skip copy/hash if (src == dst). Nvme-tcp is the first user for these.

Asynchronous completion:
=========================================
The NIC must release its mapping between command IDs and the target buffers.
This mapping is released when NVMe-TCP calls the NIC
driver (`nvme_tcp_offload_socket`).
As completing IOs is performance criticial, we introduce asynchronous
completions for NVMe-TCP, i.e. NVMe-TCP calls the NIC, which will later
call NVMe-TCP to complete the IO (`nvme_tcp_ddp_teardown_done`).

An alternative approach is to move all the functions related to coping from
SKBs to the block layer buffers inside the nvme-tcp code - about 200 LOC.

CRC offload works as follows:
=========================================
After offload is initialized, we use the SKB's ddp_crc bit to indicate that:
"there was no problem with the verification of all CRC fields in this packet's
payload". The bit is set to zero if there was an error, or if HW skipped
offload for some reason. If *any* SKB in a PDU has (ddp_crc != 1), then software
must compute the CRC, and check it. We perform this check, and
accompanying software fallback at the end of the processing of a received PDU.

SKB changes:
=========================================
The CRC offload requires an additional bit in the SKB, which is useful for
preventing the coalescing of SKB with different crc offload values. This bit
is similar in concept to the "decrypted" bit. 

Performance:
=========================================
The expected performance gain from this offload varies with the block size.
We perform a CPU cycles breakdown of the copy/CRC operations in nvme-tcp
fio random read workloads:
For 4K blocks we see up to 11% improvement for a 100% read fio workload,
while for 128K blocks we see upto 52%. If we run nvme-tcp, and skip these
operations, then we observe a gain of about 1.1x and 2x respectively.

Resynchronization:
=========================================
The resynchronization flow is performed to reset the hardware tracking of
NVMe-TCP PDUs within the TCP stream. The flow consists of a request from
the driver, regarding a possible location of a PDU header. Followed by
a response from the nvme-tcp driver.

This flow is rare, and it should happen only after packet loss or
reordering events that involve nvme-tcp PDU headers.

The patches are organized as follows:
=========================================
Patch 1         the iov_iter change to skip copy if (src == dst).
Patches 2-4     the infrastructure for all TCP DDP.
                and TCP DDP CRC offloads, respectively.
Patch 5         exposes the get_netdev_for_sock function from TLS.
Patch 6         NVMe-TCP changes to call NIC driver on queue init/teardown.
Patches 7       NVMe-TCP changes to call NIC driver on IO operation.
                setup/teardown, and support async completions.
Patches 8       NVMe-TCP changes to support CRC offload on receive.
                Also, this patch moves CRC calculation to the end of PDU
                in case offload requires software fallback.
Patches 9       NVMe-TCP handling of netdev events: stop the offload if
                netdev is going down.
Patches 10-20   implement support for NVMe-TCP copy and CRC offload in
                the mlx5 NIC driver as the first user.
Patches 21      Document TCP DDP offload.

Testing:
=========================================
This series was tested using fio with various configurations of IO sizes,
depths, MTUs, and with both the SPDK and kernel NVMe-TCP targets.
Also, we have used QEMU and gate-level simulation to verify these patches.

Future work:
=========================================
A follow-up series will introduce support for transmit side CRC. Then,
we will work on adding support for TLS in NVMe-TCP and combining the
two offloads.

Ben Ben-Ishay (8):
  net/mlx5e: NVMEoTCP offload initialization
  net/mlx5e: KLM UMR helper macros
  net/mlx5e: NVMEoTCP use KLM UMRs
  net/mlx5e: NVMEoTCP queue init/teardown
  net/mlx5e: NVMEoTCP async ddp invalidation
  net/mlx5e: NVMEoTCP ddp setup and resync
  net/mlx5e: NVMEoTCP, data-path for DDP offload
  net/mlx5e: NVMEoTCP statistics

Ben Ben-ishay (4):
  net: SKB copy(+hash) iterators for DDP offloads
  nvme-tcp : Recalculate crc in the end of the capsule
  net/mlx5: Header file changes for nvme-tcp offload
  net/mlx5: Add 128B CQE for NVMEoTCP offload

Boris Pismenny (8):
  iov_iter: Introduce new procedures for copy to iter/pages
  net: Introduce direct data placement tcp offload
  net: Introduce crc offload for tcp ddp ulp
  net/tls: expose get_netdev_for_sock
  nvme-tcp: Add DDP offload control path
  nvme-tcp: Add DDP data-path
  net/mlx5e: TCP flow steering for nvme-tcp
  Documentation: add TCP DDP offload documentation

Or Gerlitz (1):
  nvme-tcp: Deal with netdevice DOWN events

 Documentation/networking/index.rst            |    1 +
 Documentation/networking/tcp-ddp-offload.rst  |  296 +++++
 .../net/ethernet/mellanox/mlx5/core/Kconfig   |   11 +
 .../net/ethernet/mellanox/mlx5/core/Makefile  |    2 +
 drivers/net/ethernet/mellanox/mlx5/core/en.h  |   31 +-
 .../net/ethernet/mellanox/mlx5/core/en/fs.h   |    4 +-
 .../ethernet/mellanox/mlx5/core/en/params.h   |    1 +
 .../net/ethernet/mellanox/mlx5/core/en/txrx.h |   13 +
 .../ethernet/mellanox/mlx5/core/en/xsk/rx.c   |    1 +
 .../ethernet/mellanox/mlx5/core/en/xsk/rx.h   |    1 +
 .../mellanox/mlx5/core/en_accel/en_accel.h    |    9 +-
 .../mellanox/mlx5/core/en_accel/fs_tcp.c      |   10 +
 .../mellanox/mlx5/core/en_accel/fs_tcp.h      |    2 +-
 .../mellanox/mlx5/core/en_accel/nvmeotcp.c    | 1012 +++++++++++++++++
 .../mellanox/mlx5/core/en_accel/nvmeotcp.h    |  120 ++
 .../mlx5/core/en_accel/nvmeotcp_rxtx.c        |  259 +++++
 .../mlx5/core/en_accel/nvmeotcp_rxtx.h        |   43 +
 .../mlx5/core/en_accel/nvmeotcp_utils.h       |   80 ++
 .../net/ethernet/mellanox/mlx5/core/en_main.c |   39 +-
 .../net/ethernet/mellanox/mlx5/core/en_rx.c   |   66 +-
 .../ethernet/mellanox/mlx5/core/en_stats.c    |   37 +
 .../ethernet/mellanox/mlx5/core/en_stats.h    |   24 +
 .../net/ethernet/mellanox/mlx5/core/en_txrx.c |   17 +
 drivers/net/ethernet/mellanox/mlx5/core/fw.c  |    6 +
 drivers/nvme/host/tcp.c                       |  466 +++++++-
 include/linux/mlx5/device.h                   |   44 +-
 include/linux/mlx5/mlx5_ifc.h                 |  101 +-
 include/linux/mlx5/qp.h                       |    1 +
 include/linux/netdev_features.h               |    4 +
 include/linux/netdevice.h                     |    5 +
 include/linux/skbuff.h                        |   10 +
 include/linux/uio.h                           |   12 +
 include/net/inet_connection_sock.h            |    4 +
 include/net/sock.h                            |   17 +
 include/net/tcp_ddp.h                         |  136 +++
 lib/iov_iter.c                                |   45 +
 net/Kconfig                                   |   17 +
 net/core/datagram.c                           |   44 +
 net/core/skbuff.c                             |    9 +-
 net/ethtool/common.c                          |    2 +
 net/ipv4/tcp_input.c                          |    7 +
 net/ipv4/tcp_ipv4.c                           |    3 +
 net/ipv4/tcp_offload.c                        |    3 +
 net/tls/tls_device.c                          |   20 +-
 44 files changed, 2977 insertions(+), 58 deletions(-)
 create mode 100644 Documentation/networking/tcp-ddp-offload.rst
 create mode 100644 drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.c
 create mode 100644 drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.h
 create mode 100644 drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp_rxtx.c
 create mode 100644 drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp_rxtx.h
 create mode 100644 drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp_utils.h
 create mode 100644 include/net/tcp_ddp.h

-- 
2.24.1

[PATCH v2 net-next 01/21] iov_iter: Introduce new procedures for copy to iter/pages

[Boris Pismenny]

When using direct data placement the NIC writes some of the payload
directly to the destination buffer, and constructs the SKB such that it
points to this data. As a result, the skb_copy datagram_iter call will
attempt to copy data when it is not necessary.

Introduce new procedures for copy to iter/pages in case that the
source of the copy operation might be identical to the destination,
in such cases the copy is skipped only for bio_vec, later commits
uses those functions to introduce new skb copy(+hash) functions.

Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: Ben Ben-Ishay <benishay@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Yoray Zack <yorayz@mellanox.com>
---
 include/linux/uio.h | 12 ++++++++++++
 lib/iov_iter.c      | 45 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 57 insertions(+)

diff --git a/include/linux/uio.h b/include/linux/uio.h
index 72d88566694e..3c42125a7f24 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -123,6 +123,7 @@ size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes,
 			 struct iov_iter *i);
 
 size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i);
+size_t _ddp_copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i);
 size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i);
 bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i);
 size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i);
@@ -137,6 +138,15 @@ size_t copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
 		return _copy_to_iter(addr, bytes, i);
 }
 
+static __always_inline __must_check
+size_t ddp_copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
+{
+	if (unlikely(!check_copy_size(addr, bytes, true)))
+		return 0;
+	else
+		return _ddp_copy_to_iter(addr, bytes, i);
+}
+
 static __always_inline __must_check
 size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
 {
@@ -265,6 +275,8 @@ size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, struct io
 bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i);
 size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp,
 		struct iov_iter *i);
+size_t ddp_hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp,
+		struct iov_iter *i);
 
 struct iovec *iovec_from_user(const struct iovec __user *uvector,
 		unsigned long nr_segs, unsigned long fast_segs,
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 1635111c5bd2..92c07cf4a3c9 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -473,6 +473,16 @@ static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t
 	kunmap_atomic(from);
 }
 
+static void ddp_memcpy_to_page(struct page *page, size_t offset, const char *from, size_t len)
+{
+	char *to = kmap_atomic(page);
+
+	if (to + offset != from)
+		memcpy(to + offset, from, len);
+
+	kunmap_atomic(to);
+}
+
 static void memcpy_to_page(struct page *page, size_t offset, const char *from, size_t len)
 {
 	char *to = kmap_atomic(page);
@@ -625,6 +635,22 @@ static size_t csum_and_copy_to_pipe_iter(const void *addr, size_t bytes,
 	return bytes;
 }
 
+size_t _ddp_copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
+{
+	const char *from = addr;
+	if (unlikely(iov_iter_is_pipe(i)))
+		return copy_pipe_to_iter(addr, bytes, i);
+	if (iter_is_iovec(i))
+		might_fault();
+	iterate_and_advance(i, bytes, v, NULL,
+		ddp_memcpy_to_page(v.bv_page, v.bv_offset,
+				   (from += v.bv_len) - v.bv_len, v.bv_len),
+		NULL)
+
+	return bytes;
+}
+EXPORT_SYMBOL(_ddp_copy_to_iter);
+
 size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
 {
 	const char *from = addr;
@@ -1566,6 +1592,25 @@ size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *csump,
 }
 EXPORT_SYMBOL(csum_and_copy_to_iter);
 
+size_t ddp_hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp,
+		struct iov_iter *i)
+{
+#ifdef CONFIG_CRYPTO_HASH
+	struct ahash_request *hash = hashp;
+	struct scatterlist sg;
+	size_t copied;
+
+	copied = ddp_copy_to_iter(addr, bytes, i);
+	sg_init_one(&sg, addr, copied);
+	ahash_request_set_crypt(hash, &sg, NULL, copied);
+	crypto_ahash_update(hash);
+	return copied;
+#else
+	return 0;
+#endif
+}
+EXPORT_SYMBOL(ddp_hash_and_copy_to_iter);
+
 size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp,
 		struct iov_iter *i)
 {
-- 
2.24.1

[PATCH v2 net-next 02/21] net: Introduce direct data placement tcp offload

[Boris Pismenny]

This commit introduces direct data placement offload for TCP.
This capability is accompanied by new net_device operations that
configure hardware contexts. There is a context per socket, and a context per DDP
opreation. Additionally, a resynchronization routine is used to assist
hardware handle TCP OOO, and continue the offload.
Furthermore, we let the offloading driver advertise what is the max hw
sectors/segments.

Using this interface, the NIC hardware will scatter TCP payload directly
to the BIO pages according to the command_id.
To maintain the correctness of the network stack, the driver is expected
to construct SKBs that point to the BIO pages.

This, the SKB represents the data on the wire, while it is pointing
to data that is already placed in the destination buffer.
As a result, data from page frags should not be copied out to
the linear part.

As SKBs that use DDP are already very memory efficient, we modify
skb_condence to avoid copying data from fragments to the linear
part of SKBs that belong to a socket that uses DDP offload.

A follow-up patch will use this interface for DDP in NVMe-TCP.

Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: Ben Ben-Ishay <benishay@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Yoray Zack <yorayz@mellanox.com>
---
 include/linux/netdev_features.h    |   2 +
 include/linux/netdevice.h          |   5 ++
 include/net/inet_connection_sock.h |   4 +
 include/net/tcp_ddp.h              | 136 +++++++++++++++++++++++++++++
 net/Kconfig                        |   9 ++
 net/core/skbuff.c                  |   9 +-
 net/ethtool/common.c               |   1 +
 7 files changed, 165 insertions(+), 1 deletion(-)
 create mode 100644 include/net/tcp_ddp.h

diff --git a/include/linux/netdev_features.h b/include/linux/netdev_features.h
index 934de56644e7..fb35dcac03d2 100644
--- a/include/linux/netdev_features.h
+++ b/include/linux/netdev_features.h
@@ -84,6 +84,7 @@ enum {
 	NETIF_F_GRO_FRAGLIST_BIT,	/* Fraglist GRO */
 
 	NETIF_F_HW_MACSEC_BIT,		/* Offload MACsec operations */
+	NETIF_F_HW_TCP_DDP_BIT,		/* TCP direct data placement offload */
 
 	/*
 	 * Add your fresh new feature above and remember to update
@@ -157,6 +158,7 @@ enum {
 #define NETIF_F_GRO_FRAGLIST	__NETIF_F(GRO_FRAGLIST)
 #define NETIF_F_GSO_FRAGLIST	__NETIF_F(GSO_FRAGLIST)
 #define NETIF_F_HW_MACSEC	__NETIF_F(HW_MACSEC)
+#define NETIF_F_HW_TCP_DDP	__NETIF_F(HW_TCP_DDP)
 
 /* Finds the next feature with the highest number of the range of start till 0.
  */
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 259be67644e3..3dd3cdf5dec3 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -941,6 +941,7 @@ struct dev_ifalias {
 
 struct devlink;
 struct tlsdev_ops;
+struct tcp_ddp_dev_ops;
 
 struct netdev_name_node {
 	struct hlist_node hlist;
@@ -1937,6 +1938,10 @@ struct net_device {
 	const struct tlsdev_ops *tlsdev_ops;
 #endif
 
+#ifdef CONFIG_TCP_DDP
+	const struct tcp_ddp_dev_ops *tcp_ddp_ops;
+#endif
+
 	const struct header_ops *header_ops;
 
 	unsigned int		flags;
diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connection_sock.h
index 7338b3865a2a..a08b85b53aa8 100644
--- a/include/net/inet_connection_sock.h
+++ b/include/net/inet_connection_sock.h
@@ -66,6 +66,8 @@ struct inet_connection_sock_af_ops {
  * @icsk_ulp_ops	   Pluggable ULP control hook
  * @icsk_ulp_data	   ULP private data
  * @icsk_clean_acked	   Clean acked data hook
+ * @icsk_ulp_ddp_ops	   Pluggable ULP direct data placement control hook
+ * @icsk_ulp_ddp_data	   ULP direct data placement private data
  * @icsk_listen_portaddr_node	hash to the portaddr listener hashtable
  * @icsk_ca_state:	   Congestion control state
  * @icsk_retransmits:	   Number of unrecovered [RTO] timeouts
@@ -94,6 +96,8 @@ struct inet_connection_sock {
 	const struct tcp_ulp_ops  *icsk_ulp_ops;
 	void __rcu		  *icsk_ulp_data;
 	void (*icsk_clean_acked)(struct sock *sk, u32 acked_seq);
+	const struct tcp_ddp_ulp_ops  *icsk_ulp_ddp_ops;
+	void __rcu		  *icsk_ulp_ddp_data;
 	struct hlist_node         icsk_listen_portaddr_node;
 	unsigned int		  (*icsk_sync_mss)(struct sock *sk, u32 pmtu);
 	__u8			  icsk_ca_state:5,
diff --git a/include/net/tcp_ddp.h b/include/net/tcp_ddp.h
new file mode 100644
index 000000000000..31e5b1a16d0f
--- /dev/null
+++ b/include/net/tcp_ddp.h
@@ -0,0 +1,136 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * tcp_ddp.h
+ *	Author:	Boris Pismenny <borisp@mellanox.com>
+ *	Copyright (C) 2021 Mellanox Technologies.
+ */
+#ifndef _TCP_DDP_H
+#define _TCP_DDP_H
+
+#include <linux/netdevice.h>
+#include <net/inet_connection_sock.h>
+#include <net/sock.h>
+
+/* limits returned by the offload driver, zero means don't care */
+struct tcp_ddp_limits {
+	int	 max_ddp_sgl_len;
+};
+
+enum tcp_ddp_type {
+	TCP_DDP_NVME = 1,
+};
+
+/**
+ * struct tcp_ddp_config - Generic tcp ddp configuration: tcp ddp IO queue
+ * config implementations must use this as the first member.
+ * Add new instances of tcp_ddp_config below (nvme-tcp, etc.).
+ */
+struct tcp_ddp_config {
+	enum tcp_ddp_type    type;
+	unsigned char        buf[];
+};
+
+/**
+ * struct nvme_tcp_ddp_config - nvme tcp ddp configuration for an IO queue
+ *
+ * @pfv:        pdu version (e.g., NVME_TCP_PFV_1_0)
+ * @cpda:       controller pdu data alignmend (dwords, 0's based)
+ * @dgst:       digest types enabled.
+ *              The netdev will offload crc if ddp_crc is supported.
+ * @queue_size: number of nvme-tcp IO queue elements
+ * @queue_id:   queue identifier
+ * @cpu_io:     cpu core running the IO thread for this queue
+ */
+struct nvme_tcp_ddp_config {
+	struct tcp_ddp_config   cfg;
+
+	u16			pfv;
+	u8			cpda;
+	u8			dgst;
+	int			queue_size;
+	int			queue_id;
+	int			io_cpu;
+};
+
+/**
+ * struct tcp_ddp_io - tcp ddp configuration for an IO request.
+ *
+ * @command_id:  identifier on the wire associated with these buffers
+ * @nents:       number of entries in the sg_table
+ * @sg_table:    describing the buffers for this IO request
+ * @first_sgl:   first SGL in sg_table
+ */
+struct tcp_ddp_io {
+	u32			command_id;
+	int			nents;
+	struct sg_table		sg_table;
+	struct scatterlist	first_sgl[SG_CHUNK_SIZE];
+};
+
+/* struct tcp_ddp_dev_ops - operations used by an upper layer protocol to configure ddp offload
+ *
+ * @tcp_ddp_limits:    limit the number of scatter gather entries per IO.
+ *                     the device driver can use this to limit the resources allocated per queue.
+ * @tcp_ddp_sk_add:    add offload for the queue represennted by the socket+config pair.
+ *                     this function is used to configure either copy, crc or both offloads.
+ * @tcp_ddp_sk_del:    remove offload from the socket, and release any device related resources.
+ * @tcp_ddp_setup:     request copy offload for buffers associated with a command_id in tcp_ddp_io.
+ * @tcp_ddp_teardown:  release offload resources association between buffers and command_id in
+ *                     tcp_ddp_io.
+ * @tcp_ddp_resync:    respond to the driver's resync_request. Called only if resync is successful.
+ */
+struct tcp_ddp_dev_ops {
+	int (*tcp_ddp_limits)(struct net_device *netdev,
+			      struct tcp_ddp_limits *limits);
+	int (*tcp_ddp_sk_add)(struct net_device *netdev,
+			      struct sock *sk,
+			      struct tcp_ddp_config *config);
+	void (*tcp_ddp_sk_del)(struct net_device *netdev,
+			       struct sock *sk);
+	int (*tcp_ddp_setup)(struct net_device *netdev,
+			     struct sock *sk,
+			     struct tcp_ddp_io *io);
+	int (*tcp_ddp_teardown)(struct net_device *netdev,
+				struct sock *sk,
+				struct tcp_ddp_io *io,
+				void *ddp_ctx);
+	void (*tcp_ddp_resync)(struct net_device *netdev,
+			       struct sock *sk, u32 seq);
+};
+
+#define TCP_DDP_RESYNC_REQ BIT(0)
+
+/**
+ * struct tcp_ddp_ulp_ops - Interface to register uppper layer Direct Data Placement (DDP) TCP offload
+ */
+struct tcp_ddp_ulp_ops {
+	/* NIC requests ulp to indicate if @seq is the start of a message */
+	bool (*resync_request)(struct sock *sk, u32 seq, u32 flags);
+	/* NIC driver informs the ulp that ddp teardown is done - used for async completions*/
+	void (*ddp_teardown_done)(void *ddp_ctx);
+};
+
+/**
+ * struct tcp_ddp_ctx - Generic tcp ddp context: device driver per queue contexts must
+ * use this as the first member.
+ */
+struct tcp_ddp_ctx {
+	enum tcp_ddp_type    type;
+	unsigned char        buf[];
+};
+
+static inline struct tcp_ddp_ctx *tcp_ddp_get_ctx(const struct sock *sk)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+
+	return (__force struct tcp_ddp_ctx *)icsk->icsk_ulp_ddp_data;
+}
+
+static inline void tcp_ddp_set_ctx(struct sock *sk, void *ctx)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+
+	rcu_assign_pointer(icsk->icsk_ulp_ddp_data, ctx);
+}
+
+#endif //_TCP_DDP_H
diff --git a/net/Kconfig b/net/Kconfig
index f4c32d982af6..3876861cdc90 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -457,6 +457,15 @@ config ETHTOOL_NETLINK
 	  netlink. It provides better extensibility and some new features,
 	  e.g. notification messages.
 
+config TCP_DDP
+	bool "TCP direct data placement offload"
+	default n
+	help
+	  Direct Data Placement (DDP) offload for TCP enables ULP, such as
+	  NVMe-TCP/iSCSI, to request the NIC to place TCP payload data
+	  of a command response directly into kernel pages.
+
+
 endif   # if NET
 
 # Used by archs to tell that they support BPF JIT compiler plus which flavour.
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index f62cae3f75d8..791c1b6bc067 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -69,6 +69,7 @@
 #include <net/xfrm.h>
 #include <net/mpls.h>
 #include <net/mptcp.h>
+#include <net/tcp_ddp.h>
 
 #include <linux/uaccess.h>
 #include <trace/events/skb.h>
@@ -6140,9 +6141,15 @@ EXPORT_SYMBOL(pskb_extract);
  */
 void skb_condense(struct sk_buff *skb)
 {
+	bool is_ddp = false;
+
+#ifdef CONFIG_TCP_DDP
+	is_ddp = skb->sk && inet_csk(skb->sk) &&
+		 inet_csk(skb->sk)->icsk_ulp_ddp_data;
+#endif
 	if (skb->data_len) {
 		if (skb->data_len > skb->end - skb->tail ||
-		    skb_cloned(skb))
+		    skb_cloned(skb) || is_ddp)
 			return;
 
 		/* Nice, we can free page frag(s) right now */
diff --git a/net/ethtool/common.c b/net/ethtool/common.c
index 24036e3055a1..a2ff7a4a6bbf 100644
--- a/net/ethtool/common.c
+++ b/net/ethtool/common.c
@@ -68,6 +68,7 @@ const char netdev_features_strings[NETDEV_FEATURE_COUNT][ETH_GSTRING_LEN] = {
 	[NETIF_F_HW_TLS_RX_BIT] =	 "tls-hw-rx-offload",
 	[NETIF_F_GRO_FRAGLIST_BIT] =	 "rx-gro-list",
 	[NETIF_F_HW_MACSEC_BIT] =	 "macsec-hw-offload",
+	[NETIF_F_HW_TCP_DDP_BIT] =	 "tcp-ddp-offload",
 };
 
 const char
-- 
2.24.1

[PATCH v2 net-next 03/21] net: Introduce crc offload for tcp ddp ulp

[Boris Pismenny]

This commit introduces support for CRC offload to direct data placement
ULP on the receive side. Both DDP and CRC share a common API to
initialize the offload for a TCP socket. But otherwise, both can
be executed independently.

On the receive side, CRC offload requires a new SKB bit that
indicates that no CRC error was encountered while processing this packet.
If all packets of a ULP message have this bit set, then the CRC
verification for the message can be skipped, as hardware already checked
it.

The following patches will set and use this bit to perform NVME-TCP
CRC offload.

A subsequent series, will add NVMe-TCP transmit side CRC support.

Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: Ben Ben-Ishay <benishay@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Yoray Zack <yorayz@mellanox.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
---
 include/linux/netdev_features.h | 2 ++
 include/linux/skbuff.h          | 5 +++++
 net/Kconfig                     | 8 ++++++++
 net/ethtool/common.c            | 1 +
 net/ipv4/tcp_input.c            | 7 +++++++
 net/ipv4/tcp_ipv4.c             | 3 +++
 net/ipv4/tcp_offload.c          | 3 +++
 7 files changed, 29 insertions(+)

diff --git a/include/linux/netdev_features.h b/include/linux/netdev_features.h
index fb35dcac03d2..dc79709586cd 100644
--- a/include/linux/netdev_features.h
+++ b/include/linux/netdev_features.h
@@ -85,6 +85,7 @@ enum {
 
 	NETIF_F_HW_MACSEC_BIT,		/* Offload MACsec operations */
 	NETIF_F_HW_TCP_DDP_BIT,		/* TCP direct data placement offload */
+	NETIF_F_HW_TCP_DDP_CRC_RX_BIT,	/* TCP DDP CRC RX offload */
 
 	/*
 	 * Add your fresh new feature above and remember to update
@@ -159,6 +160,7 @@ enum {
 #define NETIF_F_GSO_FRAGLIST	__NETIF_F(GSO_FRAGLIST)
 #define NETIF_F_HW_MACSEC	__NETIF_F(HW_MACSEC)
 #define NETIF_F_HW_TCP_DDP	__NETIF_F(HW_TCP_DDP)
+#define NETIF_F_HW_TCP_DDP_CRC_RX	__NETIF_F(HW_TCP_DDP_CRC_RX)
 
 /* Finds the next feature with the highest number of the range of start till 0.
  */
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 333bcdc39635..a841bc974452 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -683,6 +683,7 @@ typedef unsigned char *sk_buff_data_t;
  *		CHECKSUM_UNNECESSARY (max 3)
  *	@dst_pending_confirm: need to confirm neighbour
  *	@decrypted: Decrypted SKB
+ *	@ddp_crc: NIC is responsible for PDU's CRC computation and verification
  *	@napi_id: id of the NAPI struct this skb came from
  *	@sender_cpu: (aka @napi_id) source CPU in XPS
  *	@secmark: security marking
@@ -859,6 +860,10 @@ struct sk_buff {
 #ifdef CONFIG_TLS_DEVICE
 	__u8			decrypted:1;
 #endif
+#ifdef CONFIG_TCP_DDP_CRC
+	__u8                    ddp_crc:1;
+#endif
+
 
 #ifdef CONFIG_NET_SCHED
 	__u16			tc_index;	/* traffic control index */
diff --git a/net/Kconfig b/net/Kconfig
index 3876861cdc90..80ed9f038968 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -465,6 +465,14 @@ config TCP_DDP
 	  NVMe-TCP/iSCSI, to request the NIC to place TCP payload data
 	  of a command response directly into kernel pages.
 
+config TCP_DDP_CRC
+	bool "TCP direct data placement CRC offload"
+	default n
+	help
+	  Direct Data Placement (DDP) CRC32C offload for TCP enables ULP, such as
+	  NVMe-TCP/iSCSI, to request the NIC to calculate/verify the data digest
+	  of commands as they go through the NIC. Thus avoiding the costly
+	  per-byte overhead.
 
 endif   # if NET
 
diff --git a/net/ethtool/common.c b/net/ethtool/common.c
index a2ff7a4a6bbf..cc6858105449 100644
--- a/net/ethtool/common.c
+++ b/net/ethtool/common.c
@@ -69,6 +69,7 @@ const char netdev_features_strings[NETDEV_FEATURE_COUNT][ETH_GSTRING_LEN] = {
 	[NETIF_F_GRO_FRAGLIST_BIT] =	 "rx-gro-list",
 	[NETIF_F_HW_MACSEC_BIT] =	 "macsec-hw-offload",
 	[NETIF_F_HW_TCP_DDP_BIT] =	 "tcp-ddp-offload",
+	[NETIF_F_HW_TCP_DDP_CRC_RX_BIT] =	 "tcp-ddp-crc-rx-offload",
 };
 
 const char
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index c7e16b0ed791..090c695e18b8 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -5147,6 +5147,9 @@ tcp_collapse(struct sock *sk, struct sk_buff_head *list, struct rb_root *root,
 		memcpy(nskb->cb, skb->cb, sizeof(skb->cb));
 #ifdef CONFIG_TLS_DEVICE
 		nskb->decrypted = skb->decrypted;
+#endif
+#ifdef CONFIG_TCP_DDP_CRC
+		nskb->ddp_crc = skb->ddp_crc;
 #endif
 		TCP_SKB_CB(nskb)->seq = TCP_SKB_CB(nskb)->end_seq = start;
 		if (list)
@@ -5180,6 +5183,10 @@ tcp_collapse(struct sock *sk, struct sk_buff_head *list, struct rb_root *root,
 #ifdef CONFIG_TLS_DEVICE
 				if (skb->decrypted != nskb->decrypted)
 					goto end;
+#endif
+#ifdef CONFIG_TCP_DDP_CRC
+				if (skb->ddp_crc != nskb->ddp_crc)
+					goto end;
 #endif
 			}
 		}
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 58207c7769d0..64ccaf08fb3a 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1815,6 +1815,9 @@ bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb)
 	      TCP_SKB_CB(skb)->tcp_flags) & (TCPHDR_ECE | TCPHDR_CWR)) ||
 #ifdef CONFIG_TLS_DEVICE
 	    tail->decrypted != skb->decrypted ||
+#endif
+#ifdef CONFIG_TCP_DDP_CRC
+	    tail->ddp_crc != skb->ddp_crc ||
 #endif
 	    thtail->doff != th->doff ||
 	    memcmp(thtail + 1, th + 1, hdrlen - sizeof(*th)))
diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c
index e09147ac9a99..39f5f0bcf181 100644
--- a/net/ipv4/tcp_offload.c
+++ b/net/ipv4/tcp_offload.c
@@ -262,6 +262,9 @@ struct sk_buff *tcp_gro_receive(struct list_head *head, struct sk_buff *skb)
 #ifdef CONFIG_TLS_DEVICE
 	flush |= p->decrypted ^ skb->decrypted;
 #endif
+#ifdef CONFIG_TCP_DDP_CRC
+	flush |= p->ddp_crc ^ skb->ddp_crc;
+#endif
 
 	if (flush || skb_gro_receive(p, skb)) {
 		mss = 1;
-- 
2.24.1

[PATCH v2 net-next 04/21] net: SKB copy(+hash) iterators for DDP offloads

[Boris Pismenny]

From: Ben Ben-ishay <benishay@nvidia.com>

This commit introduces new functions to support direct data placement
operation, when using direct data placement the copy of the data from
the SKB to the destination buffer might be unnecessary and thus the
copy should be skipped, those functions take care of it in cases that
the destination buffer is represented by bio_vec.

Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: Ben Ben-Ishay <benishay@nvidia.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Yoray Zack <yorayz@mellanox.com>
---
 include/linux/skbuff.h |  5 +++++
 net/core/datagram.c    | 44 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 49 insertions(+)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index a841bc974452..96847aabba5b 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -3536,6 +3536,8 @@ __poll_t datagram_poll(struct file *file, struct socket *sock,
 			   struct poll_table_struct *wait);
 int skb_copy_datagram_iter(const struct sk_buff *from, int offset,
 			   struct iov_iter *to, int size);
+int skb_ddp_copy_datagram_iter(const struct sk_buff *from, int offset,
+			       struct iov_iter *to, int size);
 static inline int skb_copy_datagram_msg(const struct sk_buff *from, int offset,
 					struct msghdr *msg, int size)
 {
@@ -3546,6 +3548,9 @@ int skb_copy_and_csum_datagram_msg(struct sk_buff *skb, int hlen,
 int skb_copy_and_hash_datagram_iter(const struct sk_buff *skb, int offset,
 			   struct iov_iter *to, int len,
 			   struct ahash_request *hash);
+int skb_ddp_copy_and_hash_datagram_iter(const struct sk_buff *skb, int offset,
+					struct iov_iter *to, int len,
+					struct ahash_request *hash);
 int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset,
 				 struct iov_iter *from, int len);
 int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *frm);
diff --git a/net/core/datagram.c b/net/core/datagram.c
index 81809fa735a7..bbc476cadc71 100644
--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -495,6 +495,25 @@ static int __skb_datagram_iter(const struct sk_buff *skb, int offset,
 	return 0;
 }
 
+/**
+ *	skb_ddp_copy_and_hash_datagram_iter - Copies datagrams from skb frags to
+ *	an iterator and update a hash. If the iterator and skb frag point to the
+ *	same page and offset, then the copy is skipped.
+ *	@skb: buffer to copy
+ *	@offset: offset in the buffer to start copying from
+ *	@to: iovec iterator to copy to
+ *	@len: amount of data to copy from buffer to iovec
+ *      @hash: hash request to update
+ */
+int skb_ddp_copy_and_hash_datagram_iter(const struct sk_buff *skb, int offset,
+					struct iov_iter *to, int len,
+					struct ahash_request *hash)
+{
+	return __skb_datagram_iter(skb, offset, to, len, true,
+			ddp_hash_and_copy_to_iter, hash);
+}
+EXPORT_SYMBOL(skb_ddp_copy_and_hash_datagram_iter);
+
 /**
  *	skb_copy_and_hash_datagram_iter - Copy datagram to an iovec iterator
  *          and update a hash.
@@ -513,6 +532,31 @@ int skb_copy_and_hash_datagram_iter(const struct sk_buff *skb, int offset,
 }
 EXPORT_SYMBOL(skb_copy_and_hash_datagram_iter);
 
+static size_t simple_ddp_copy_to_iter(const void *addr, size_t bytes,
+				      void *data __always_unused,
+				      struct iov_iter *i)
+{
+	return ddp_copy_to_iter(addr, bytes, i);
+}
+
+/**
+ *	skb_ddp_copy_datagram_iter - Copies datagrams from skb frags to an
+ *	iterator. If the iterator and skb frag point to the same page and
+ *	offset, then the copy is skipped.
+ *	@skb: buffer to copy
+ *	@offset: offset in the buffer to start copying from
+ *	@to: iovec iterator to copy to
+ *	@len: amount of data to copy from buffer to iovec
+ */
+int skb_ddp_copy_datagram_iter(const struct sk_buff *skb, int offset,
+			       struct iov_iter *to, int len)
+{
+	trace_skb_copy_datagram_iovec(skb, len);
+	return __skb_datagram_iter(skb, offset, to, len, false,
+			simple_ddp_copy_to_iter, NULL);
+}
+EXPORT_SYMBOL(skb_ddp_copy_datagram_iter);
+
 static size_t simple_copy_to_iter(const void *addr, size_t bytes,
 		void *data __always_unused, struct iov_iter *i)
 {
-- 
2.24.1

[PATCH v2 net-next 05/21] net/tls: expose get_netdev_for_sock

[Boris Pismenny]

get_netdev_for_sock is a utility that is used to obtain
the net_device structure from a connected socket.

Later patches will use this for nvme-tcp DDP and DDP CRC offloads.

Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
---
 include/net/sock.h   | 17 +++++++++++++++++
 net/tls/tls_device.c | 20 ++------------------
 2 files changed, 19 insertions(+), 18 deletions(-)

diff --git a/include/net/sock.h b/include/net/sock.h
index bdc4323ce53c..9c21a4d696ad 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -2721,4 +2721,21 @@ void sock_set_sndtimeo(struct sock *sk, s64 secs);
 
 int sock_bind_add(struct sock *sk, struct sockaddr *addr, int addr_len);
 
+/* Assume that the socket is already connected */
+static inline struct net_device *get_netdev_for_sock(struct sock *sk, bool hold)
+{
+	struct dst_entry *dst = sk_dst_get(sk);
+	struct net_device *netdev = NULL;
+
+	if (likely(dst)) {
+		netdev = dst->dev;
+		if (hold)
+			dev_hold(netdev);
+	}
+
+	dst_release(dst);
+
+	return netdev;
+}
+
 #endif	/* _SOCK_H */
diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
index f7fb7d2c1de1..cbd24d897023 100644
--- a/net/tls/tls_device.c
+++ b/net/tls/tls_device.c
@@ -106,22 +106,6 @@ static void tls_device_queue_ctx_destruction(struct tls_context *ctx)
 	spin_unlock_irqrestore(&tls_device_lock, flags);
 }
 
-/* We assume that the socket is already connected */
-static struct net_device *get_netdev_for_sock(struct sock *sk)
-{
-	struct dst_entry *dst = sk_dst_get(sk);
-	struct net_device *netdev = NULL;
-
-	if (likely(dst)) {
-		netdev = dst->dev;
-		dev_hold(netdev);
-	}
-
-	dst_release(dst);
-
-	return netdev;
-}
-
 static void destroy_record(struct tls_record_info *record)
 {
 	int i;
@@ -1106,7 +1090,7 @@ int tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
 	if (skb)
 		TCP_SKB_CB(skb)->eor = 1;
 
-	netdev = get_netdev_for_sock(sk);
+	netdev = get_netdev_for_sock(sk, true);
 	if (!netdev) {
 		pr_err_ratelimited("%s: netdev not found\n", __func__);
 		rc = -EINVAL;
@@ -1182,7 +1166,7 @@ int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx)
 	if (ctx->crypto_recv.info.version != TLS_1_2_VERSION)
 		return -EOPNOTSUPP;
 
-	netdev = get_netdev_for_sock(sk);
+	netdev = get_netdev_for_sock(sk, true);
 	if (!netdev) {
 		pr_err_ratelimited("%s: netdev not found\n", __func__);
 		return -EINVAL;
-- 
2.24.1

[PATCH v2 net-next 06/21] nvme-tcp: Add DDP offload control path

[Boris Pismenny]

This commit introduces direct data placement offload to NVME
TCP. There is a context per queue, which is established after the
handshake using the tcp_ddp_sk_add/del NDOs.

Additionally, a resynchronization routine is used to assist
hardware recovery from TCP OOO, and continue the offload.
Resynchronization operates as follows:

1. TCP OOO causes the NIC HW to stop the offload

2. NIC HW identifies a PDU header at some TCP sequence number,
and asks NVMe-TCP to confirm it.
This request is delivered from the NIC driver to NVMe-TCP by first
finding the socket for the packet that triggered the request, and
then finding the nvme_tcp_queue that is used by this routine.
Finally, the request is recorded in the nvme_tcp_queue.

3. When NVMe-TCP observes the requested TCP sequence, it will compare
it with the PDU header TCP sequence, and report the result to the
NIC driver (tcp_ddp_resync), which will update the HW,
and resume offload when all is successful.

Furthermore, we let the offloading driver advertise what is the max hw
sectors/segments via tcp_ddp_limits.

A follow-up patch introduces the data-path changes required for this
offload.

Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: Ben Ben-Ishay <benishay@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Yoray Zack <yorayz@mellanox.com>
---
 drivers/nvme/host/tcp.c | 199 +++++++++++++++++++++++++++++++++++++++-
 1 file changed, 197 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index 1ba659927442..31bf9e3ea236 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -14,6 +14,7 @@
 #include <linux/blk-mq.h>
 #include <crypto/hash.h>
 #include <net/busy_poll.h>
+#include <net/tcp_ddp.h>
 
 #include "nvme.h"
 #include "fabrics.h"
@@ -62,6 +63,7 @@ enum nvme_tcp_queue_flags {
 	NVME_TCP_Q_ALLOCATED	= 0,
 	NVME_TCP_Q_LIVE		= 1,
 	NVME_TCP_Q_POLLING	= 2,
+	NVME_TCP_Q_OFF_DDP	= 3,
 };
 
 enum nvme_tcp_recv_state {
@@ -110,6 +112,8 @@ struct nvme_tcp_queue {
 	void (*state_change)(struct sock *);
 	void (*data_ready)(struct sock *);
 	void (*write_space)(struct sock *);
+
+	atomic64_t  resync_req;
 };
 
 struct nvme_tcp_ctrl {
@@ -128,6 +132,8 @@ struct nvme_tcp_ctrl {
 	struct delayed_work	connect_work;
 	struct nvme_tcp_request async_req;
 	u32			io_queues[HCTX_MAX_TYPES];
+
+	struct net_device       *offloading_netdev;
 };
 
 static LIST_HEAD(nvme_tcp_ctrl_list);
@@ -222,6 +228,182 @@ static inline size_t nvme_tcp_pdu_last_send(struct nvme_tcp_request *req,
 	return nvme_tcp_pdu_data_left(req) <= len;
 }
 
+#ifdef CONFIG_TCP_DDP
+
+static bool nvme_tcp_resync_request(struct sock *sk, u32 seq, u32 flags);
+static const struct tcp_ddp_ulp_ops nvme_tcp_ddp_ulp_ops = {
+	.resync_request		= nvme_tcp_resync_request,
+};
+
+static
+int nvme_tcp_offload_socket(struct nvme_tcp_queue *queue)
+{
+	struct net_device *netdev = get_netdev_for_sock(queue->sock->sk, true);
+	struct nvme_tcp_ddp_config config = {};
+	int ret;
+
+	if (!netdev) {
+		dev_info_ratelimited(queue->ctrl->ctrl.device, "netdev not found\n");
+		return -ENODEV;
+	}
+
+	if (!(netdev->features & NETIF_F_HW_TCP_DDP)) {
+		dev_put(netdev);
+		return -EOPNOTSUPP;
+	}
+
+	config.cfg.type		= TCP_DDP_NVME;
+	config.pfv		= NVME_TCP_PFV_1_0;
+	config.cpda		= 0;
+	config.dgst		= queue->hdr_digest ?
+		NVME_TCP_HDR_DIGEST_ENABLE : 0;
+	config.dgst		|= queue->data_digest ?
+		NVME_TCP_DATA_DIGEST_ENABLE : 0;
+	config.queue_size	= queue->queue_size;
+	config.queue_id		= nvme_tcp_queue_id(queue);
+	config.io_cpu		= queue->io_cpu;
+
+	ret = netdev->tcp_ddp_ops->tcp_ddp_sk_add(netdev,
+						  queue->sock->sk,
+						  (struct tcp_ddp_config *)&config);
+	if (ret) {
+		dev_put(netdev);
+		return ret;
+	}
+
+	inet_csk(queue->sock->sk)->icsk_ulp_ddp_ops = &nvme_tcp_ddp_ulp_ops;
+	if (netdev->features & NETIF_F_HW_TCP_DDP)
+		set_bit(NVME_TCP_Q_OFF_DDP, &queue->flags);
+
+	return ret;
+}
+
+static
+void nvme_tcp_unoffload_socket(struct nvme_tcp_queue *queue)
+{
+	struct net_device *netdev = queue->ctrl->offloading_netdev;
+
+	if (!netdev) {
+		dev_info_ratelimited(queue->ctrl->ctrl.device, "netdev not found\n");
+		return;
+	}
+
+	netdev->tcp_ddp_ops->tcp_ddp_sk_del(netdev, queue->sock->sk);
+
+	inet_csk(queue->sock->sk)->icsk_ulp_ddp_ops = NULL;
+	dev_put(netdev); /* put the queue_init get_netdev_for_sock() */
+}
+
+static
+int nvme_tcp_offload_limits(struct nvme_tcp_queue *queue)
+{
+	struct net_device *netdev = get_netdev_for_sock(queue->sock->sk, true);
+	struct tcp_ddp_limits limits;
+	int ret = 0;
+
+	if (!netdev) {
+		dev_info_ratelimited(queue->ctrl->ctrl.device, "netdev not found\n");
+		return -ENODEV;
+	}
+
+	if (netdev->features & NETIF_F_HW_TCP_DDP &&
+	    netdev->tcp_ddp_ops &&
+	    netdev->tcp_ddp_ops->tcp_ddp_limits)
+		ret = netdev->tcp_ddp_ops->tcp_ddp_limits(netdev, &limits);
+	else
+		ret = -EOPNOTSUPP;
+
+	if (!ret) {
+		queue->ctrl->offloading_netdev = netdev;
+		dev_dbg_ratelimited(queue->ctrl->ctrl.device,
+				    "netdev %s offload limits: max_ddp_sgl_len %d\n",
+				    netdev->name, limits.max_ddp_sgl_len);
+		queue->ctrl->ctrl.max_segments = limits.max_ddp_sgl_len;
+		queue->ctrl->ctrl.max_hw_sectors =
+			limits.max_ddp_sgl_len << (ilog2(SZ_4K) - 9);
+	} else {
+		queue->ctrl->offloading_netdev = NULL;
+	}
+
+	dev_put(netdev);
+
+	return ret;
+}
+
+static
+void nvme_tcp_resync_response(struct nvme_tcp_queue *queue,
+			      unsigned int pdu_seq)
+{
+	struct net_device *netdev = queue->ctrl->offloading_netdev;
+	u64 resync_val;
+	u32 resync_seq;
+
+	resync_val = atomic64_read(&queue->resync_req);
+	/* Lower 32 bit flags. Check validity of the request */
+	if ((resync_val & TCP_DDP_RESYNC_REQ) == 0)
+		return;
+
+	/* Obtain and check requested sequence number: is this PDU header before the request? */
+	resync_seq = resync_val >> 32;
+	if (before(pdu_seq, resync_seq))
+		return;
+
+	if (unlikely(!netdev)) {
+		pr_info_ratelimited("%s: netdev not found\n", __func__);
+		return;
+	}
+
+	/**
+	 * The atomic operation gurarantees that we don't miss any NIC driver
+	 * resync requests submitted after the above checks.
+	 */
+	if (atomic64_cmpxchg(&queue->resync_req, resync_val,
+			     resync_val & ~TCP_DDP_RESYNC_REQ))
+		netdev->tcp_ddp_ops->tcp_ddp_resync(netdev, queue->sock->sk, pdu_seq);
+}
+
+static
+bool nvme_tcp_resync_request(struct sock *sk, u32 seq, u32 flags)
+{
+	struct nvme_tcp_queue *queue = sk->sk_user_data;
+
+	atomic64_set(&queue->resync_req,
+		     (((uint64_t)seq << 32) | flags));
+
+	return true;
+}
+
+#else
+
+static
+int nvme_tcp_offload_socket(struct nvme_tcp_queue *queue)
+{
+	return -EINVAL;
+}
+
+static
+void nvme_tcp_unoffload_socket(struct nvme_tcp_queue *queue)
+{}
+
+static
+int nvme_tcp_offload_limits(struct nvme_tcp_queue *queue)
+{
+	return -EINVAL;
+}
+
+static
+void nvme_tcp_resync_response(struct nvme_tcp_queue *queue,
+			      unsigned int pdu_seq)
+{}
+
+static
+bool nvme_tcp_resync_request(struct sock *sk, u32 seq, u32 flags)
+{
+	return false;
+}
+
+#endif
+
 static void nvme_tcp_init_iter(struct nvme_tcp_request *req,
 		unsigned int dir)
 {
@@ -627,6 +809,11 @@ static int nvme_tcp_recv_pdu(struct nvme_tcp_queue *queue, struct sk_buff *skb,
 	size_t rcv_len = min_t(size_t, *len, queue->pdu_remaining);
 	int ret;
 
+	u64 pdu_seq = TCP_SKB_CB(skb)->seq + *offset - queue->pdu_offset;
+
+	if (test_bit(NVME_TCP_Q_OFF_DDP, &queue->flags))
+		nvme_tcp_resync_response(queue, pdu_seq);
+
 	ret = skb_copy_bits(skb, *offset,
 		&pdu[queue->pdu_offset], rcv_len);
 	if (unlikely(ret))
@@ -1517,6 +1704,9 @@ static void __nvme_tcp_stop_queue(struct nvme_tcp_queue *queue)
 	kernel_sock_shutdown(queue->sock, SHUT_RDWR);
 	nvme_tcp_restore_sock_calls(queue);
 	cancel_work_sync(&queue->io_work);
+
+	if (test_bit(NVME_TCP_Q_OFF_DDP, &queue->flags))
+		nvme_tcp_unoffload_socket(queue);
 }
 
 static void nvme_tcp_stop_queue(struct nvme_ctrl *nctrl, int qid)
@@ -1534,10 +1724,13 @@ static int nvme_tcp_start_queue(struct nvme_ctrl *nctrl, int idx)
 	struct nvme_tcp_ctrl *ctrl = to_tcp_ctrl(nctrl);
 	int ret;
 
-	if (idx)
+	if (idx) {
 		ret = nvmf_connect_io_queue(nctrl, idx, false);
-	else
+		nvme_tcp_offload_socket(&ctrl->queues[idx]);
+	} else {
 		ret = nvmf_connect_admin_queue(nctrl);
+		nvme_tcp_offload_limits(&ctrl->queues[idx]);
+	}
 
 	if (!ret) {
 		set_bit(NVME_TCP_Q_LIVE, &ctrl->queues[idx].flags);
@@ -1640,6 +1833,8 @@ static int nvme_tcp_alloc_admin_queue(struct nvme_ctrl *ctrl)
 {
 	int ret;
 
+	to_tcp_ctrl(ctrl)->offloading_netdev = NULL;
+
 	ret = nvme_tcp_alloc_queue(ctrl, 0, NVME_AQ_DEPTH);
 	if (ret)
 		return ret;
-- 
2.24.1

[PATCH v2 net-next 07/21] nvme-tcp: Add DDP data-path

[Boris Pismenny]

Introduce the NVMe-TCP DDP data-path offload.
Using this interface, the NIC hardware will scatter TCP payload directly
to the BIO pages according to the command_id in the PDU.
To maintain the correctness of the network stack, the driver is expected
to construct SKBs that point to the BIO pages.

The data-path interface contains two routines: tcp_ddp_setup/teardown.
The setup provides the mapping from command_id to the request buffers,
while the teardown removes this mapping.

For efficiency, we introduce an asynchronous nvme completion, which is
split between NVMe-TCP and the NIC driver as follows:
NVMe-TCP performs the specific completion, while NIC driver performs the
generic mq_blk completion.

Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: Ben Ben-Ishay <benishay@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Yoray Zack <yorayz@mellanox.com>
---
 drivers/nvme/host/tcp.c | 141 +++++++++++++++++++++++++++++++++++++---
 1 file changed, 131 insertions(+), 10 deletions(-)

diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index 31bf9e3ea236..9a43bd31ec15 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -57,6 +57,11 @@ struct nvme_tcp_request {
 	size_t			offset;
 	size_t			data_sent;
 	enum nvme_tcp_send_state state;
+
+	bool			offloaded;
+	struct tcp_ddp_io	ddp;
+	__le16			status;
+	union nvme_result	result;
 };
 
 enum nvme_tcp_queue_flags {
@@ -231,10 +236,74 @@ static inline size_t nvme_tcp_pdu_last_send(struct nvme_tcp_request *req,
 #ifdef CONFIG_TCP_DDP
 
 static bool nvme_tcp_resync_request(struct sock *sk, u32 seq, u32 flags);
+static void nvme_tcp_ddp_teardown_done(void *ddp_ctx);
 static const struct tcp_ddp_ulp_ops nvme_tcp_ddp_ulp_ops = {
 	.resync_request		= nvme_tcp_resync_request,
+	.ddp_teardown_done	= nvme_tcp_ddp_teardown_done,
 };
 
+static
+int nvme_tcp_teardown_ddp(struct nvme_tcp_queue *queue,
+			  u16 command_id,
+			  struct request *rq)
+{
+	struct nvme_tcp_request *req = blk_mq_rq_to_pdu(rq);
+	struct net_device *netdev = queue->ctrl->offloading_netdev;
+	int ret;
+
+	if (unlikely(!netdev)) {
+		pr_info_ratelimited("%s: netdev not found\n", __func__);
+		return -EINVAL;
+	}
+
+	ret = netdev->tcp_ddp_ops->tcp_ddp_teardown(netdev, queue->sock->sk,
+						    &req->ddp, rq);
+	sg_free_table_chained(&req->ddp.sg_table, SG_CHUNK_SIZE);
+	req->offloaded = false;
+	return ret;
+}
+
+static void nvme_tcp_ddp_teardown_done(void *ddp_ctx)
+{
+	struct request *rq = ddp_ctx;
+	struct nvme_tcp_request *req = blk_mq_rq_to_pdu(rq);
+
+	if (!nvme_try_complete_req(rq, cpu_to_le16(req->status << 1), req->result))
+		nvme_complete_rq(rq);
+}
+
+static
+int nvme_tcp_setup_ddp(struct nvme_tcp_queue *queue,
+		       u16 command_id,
+		       struct request *rq)
+{
+	struct nvme_tcp_request *req = blk_mq_rq_to_pdu(rq);
+	struct net_device *netdev = queue->ctrl->offloading_netdev;
+	int ret;
+
+	req->offloaded = false;
+
+	if (unlikely(!netdev)) {
+		pr_info_ratelimited("%s: netdev not found\n", __func__);
+		return -EINVAL;
+	}
+
+	req->ddp.command_id = command_id;
+	req->ddp.sg_table.sgl = req->ddp.first_sgl;
+	ret = sg_alloc_table_chained(&req->ddp.sg_table, blk_rq_nr_phys_segments(rq),
+				     req->ddp.sg_table.sgl, SG_CHUNK_SIZE);
+	if (ret)
+		return -ENOMEM;
+	req->ddp.nents = blk_rq_map_sg(rq->q, rq, req->ddp.sg_table.sgl);
+
+	ret = netdev->tcp_ddp_ops->tcp_ddp_setup(netdev,
+						 queue->sock->sk,
+						 &req->ddp);
+	if (!ret)
+		req->offloaded = true;
+	return ret;
+}
+
 static
 int nvme_tcp_offload_socket(struct nvme_tcp_queue *queue)
 {
@@ -375,6 +444,25 @@ bool nvme_tcp_resync_request(struct sock *sk, u32 seq, u32 flags)
 
 #else
 
+static
+int nvme_tcp_setup_ddp(struct nvme_tcp_queue *queue,
+		       u16 command_id,
+		       struct request *rq)
+{
+	return -EINVAL;
+}
+
+static
+int nvme_tcp_teardown_ddp(struct nvme_tcp_queue *queue,
+			  u16 command_id,
+			  struct request *rq)
+{
+	return -EINVAL;
+}
+
+static void nvme_tcp_ddp_teardown_done(void *ddp_ctx)
+{}
+
 static
 int nvme_tcp_offload_socket(struct nvme_tcp_queue *queue)
 {
@@ -653,6 +741,7 @@ static void nvme_tcp_error_recovery(struct nvme_ctrl *ctrl)
 static int nvme_tcp_process_nvme_cqe(struct nvme_tcp_queue *queue,
 		struct nvme_completion *cqe)
 {
+	struct nvme_tcp_request *req;
 	struct request *rq;
 
 	rq = blk_mq_tag_to_rq(nvme_tcp_tagset(queue), cqe->command_id);
@@ -664,8 +753,15 @@ static int nvme_tcp_process_nvme_cqe(struct nvme_tcp_queue *queue,
 		return -EINVAL;
 	}
 
-	if (!nvme_try_complete_req(rq, cqe->status, cqe->result))
-		nvme_complete_rq(rq);
+	req = blk_mq_rq_to_pdu(rq);
+	if (req->offloaded) {
+		req->status = cqe->status;
+		req->result = cqe->result;
+		nvme_tcp_teardown_ddp(queue, cqe->command_id, rq);
+	} else {
+		if (!nvme_try_complete_req(rq, cqe->status, cqe->result))
+			nvme_complete_rq(rq);
+	}
 	queue->nr_cqe++;
 
 	return 0;
@@ -859,9 +955,18 @@ static int nvme_tcp_recv_pdu(struct nvme_tcp_queue *queue, struct sk_buff *skb,
 static inline void nvme_tcp_end_request(struct request *rq, u16 status)
 {
 	union nvme_result res = {};
+	struct nvme_tcp_request *req = blk_mq_rq_to_pdu(rq);
+	struct nvme_tcp_queue *queue = req->queue;
+	struct nvme_tcp_data_pdu *pdu = (void *)queue->pdu;
 
-	if (!nvme_try_complete_req(rq, cpu_to_le16(status << 1), res))
-		nvme_complete_rq(rq);
+	if (req->offloaded) {
+		req->status = cpu_to_le16(status << 1);
+		req->result = res;
+		nvme_tcp_teardown_ddp(queue, pdu->command_id, rq);
+	} else {
+		if (!nvme_try_complete_req(rq, cpu_to_le16(status << 1), res))
+			nvme_complete_rq(rq);
+	}
 }
 
 static int nvme_tcp_recv_data(struct nvme_tcp_queue *queue, struct sk_buff *skb,
@@ -908,12 +1013,22 @@ static int nvme_tcp_recv_data(struct nvme_tcp_queue *queue, struct sk_buff *skb,
 		recv_len = min_t(size_t, recv_len,
 				iov_iter_count(&req->iter));
 
-		if (queue->data_digest)
-			ret = skb_copy_and_hash_datagram_iter(skb, *offset,
-				&req->iter, recv_len, queue->rcv_hash);
-		else
-			ret = skb_copy_datagram_iter(skb, *offset,
-					&req->iter, recv_len);
+		if (test_bit(NVME_TCP_Q_OFF_DDP, &queue->flags)) {
+			if (queue->data_digest)
+				ret = skb_ddp_copy_and_hash_datagram_iter(skb, *offset,
+						&req->iter, recv_len, queue->rcv_hash);
+			else
+				ret = skb_ddp_copy_datagram_iter(skb, *offset,
+						&req->iter, recv_len);
+		} else {
+			if (queue->data_digest)
+				ret = skb_copy_and_hash_datagram_iter(skb, *offset,
+						&req->iter, recv_len, queue->rcv_hash);
+			else
+				ret = skb_copy_datagram_iter(skb, *offset,
+						&req->iter, recv_len);
+		}
+
 		if (ret) {
 			dev_err(queue->ctrl->ctrl.device,
 				"queue %d failed to copy request %#x data",
@@ -1137,6 +1252,7 @@ static int nvme_tcp_try_send_cmd_pdu(struct nvme_tcp_request *req)
 	bool inline_data = nvme_tcp_has_inline_data(req);
 	u8 hdgst = nvme_tcp_hdgst_len(queue);
 	int len = sizeof(*pdu) + hdgst - req->offset;
+	struct request *rq = blk_mq_rq_from_pdu(req);
 	int flags = MSG_DONTWAIT;
 	int ret;
 
@@ -1145,6 +1261,10 @@ static int nvme_tcp_try_send_cmd_pdu(struct nvme_tcp_request *req)
 	else
 		flags |= MSG_EOR;
 
+	if (test_bit(NVME_TCP_Q_OFF_DDP, &queue->flags) &&
+	    blk_rq_nr_phys_segments(rq) && rq_data_dir(rq) == READ)
+		nvme_tcp_setup_ddp(queue, pdu->cmd.common.command_id, rq);
+
 	if (queue->hdr_digest && !req->offset)
 		nvme_tcp_hdgst(queue->snd_hash, pdu, sizeof(*pdu));
 
@@ -2447,6 +2567,7 @@ static blk_status_t nvme_tcp_setup_cmd_pdu(struct nvme_ns *ns,
 	req->data_len = blk_rq_nr_phys_segments(rq) ?
 				blk_rq_payload_bytes(rq) : 0;
 	req->curr_bio = rq->bio;
+	req->offloaded = false;
 
 	if (rq_data_dir(rq) == WRITE &&
 	    req->data_len <= nvme_tcp_inline_data_size(queue))
-- 
2.24.1

[PATCH v2 net-next 08/21] nvme-tcp : Recalculate crc in the end of the capsule

[Boris Pismenny]

From: Ben Ben-ishay <benishay@nvidia.com>

crc offload of the nvme capsule. Check if all the skb bits
are on, and if not recalculate the crc in SW and check it.

This patch reworks the receive-side crc calculation to always
run at the end, so as to keep a single flow for both offload
and non-offload. This change simplifies the code, but it may degrade
performance for non-offload crc calculation.

Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: Ben Ben-Ishay <benishay@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Yoray Zack <yorayz@mellanox.com>
---
 drivers/nvme/host/tcp.c | 116 ++++++++++++++++++++++++++++++++--------
 1 file changed, 94 insertions(+), 22 deletions(-)

diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index 9a43bd31ec15..09d2e2e529cd 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -69,6 +69,7 @@ enum nvme_tcp_queue_flags {
 	NVME_TCP_Q_LIVE		= 1,
 	NVME_TCP_Q_POLLING	= 2,
 	NVME_TCP_Q_OFF_DDP	= 3,
+	NVME_TCP_Q_OFF_DDGST_RX = 4,
 };
 
 enum nvme_tcp_recv_state {
@@ -95,6 +96,7 @@ struct nvme_tcp_queue {
 	size_t			data_remaining;
 	size_t			ddgst_remaining;
 	unsigned int		nr_cqe;
+	bool			ddgst_valid;
 
 	/* send state */
 	struct nvme_tcp_request *request;
@@ -233,6 +235,55 @@ static inline size_t nvme_tcp_pdu_last_send(struct nvme_tcp_request *req,
 	return nvme_tcp_pdu_data_left(req) <= len;
 }
 
+static inline bool nvme_tcp_ddp_ddgst_ok(struct nvme_tcp_queue *queue)
+{
+	return queue->ddgst_valid;
+}
+
+static inline void nvme_tcp_ddp_ddgst_update(struct nvme_tcp_queue *queue,
+					     struct sk_buff *skb)
+{
+	if (queue->ddgst_valid)
+#ifdef CONFIG_TCP_DDP_CRC
+		queue->ddgst_valid = skb->ddp_crc;
+#else
+		queue->ddgst_valid = false;
+#endif
+}
+
+static int nvme_tcp_req_map_sg(struct nvme_tcp_request *req, struct request *rq)
+{
+	int ret;
+
+	req->ddp.sg_table.sgl = req->ddp.first_sgl;
+	ret = sg_alloc_table_chained(&req->ddp.sg_table, blk_rq_nr_phys_segments(rq),
+				     req->ddp.sg_table.sgl, SG_CHUNK_SIZE);
+	if (ret)
+		return -ENOMEM;
+	req->ddp.nents = blk_rq_map_sg(rq->q, rq, req->ddp.sg_table.sgl);
+	return 0;
+}
+
+static void nvme_tcp_ddp_ddgst_recalc(struct ahash_request *hash,
+				      struct request *rq)
+{
+	struct nvme_tcp_request *req;
+
+	if (!rq)
+		return;
+
+	req = blk_mq_rq_to_pdu(rq);
+
+	if (!req->offloaded && nvme_tcp_req_map_sg(req, rq))
+		return;
+
+	crypto_ahash_init(hash);
+	req->ddp.sg_table.sgl = req->ddp.first_sgl;
+	ahash_request_set_crypt(hash, req->ddp.sg_table.sgl, NULL,
+				le32_to_cpu(req->data_len));
+	crypto_ahash_update(hash);
+}
+
 #ifdef CONFIG_TCP_DDP
 
 static bool nvme_tcp_resync_request(struct sock *sk, u32 seq, u32 flags);
@@ -289,12 +340,9 @@ int nvme_tcp_setup_ddp(struct nvme_tcp_queue *queue,
 	}
 
 	req->ddp.command_id = command_id;
-	req->ddp.sg_table.sgl = req->ddp.first_sgl;
-	ret = sg_alloc_table_chained(&req->ddp.sg_table, blk_rq_nr_phys_segments(rq),
-				     req->ddp.sg_table.sgl, SG_CHUNK_SIZE);
+	ret = nvme_tcp_req_map_sg(req, rq);
 	if (ret)
 		return -ENOMEM;
-	req->ddp.nents = blk_rq_map_sg(rq->q, rq, req->ddp.sg_table.sgl);
 
 	ret = netdev->tcp_ddp_ops->tcp_ddp_setup(netdev,
 						 queue->sock->sk,
@@ -316,7 +364,7 @@ int nvme_tcp_offload_socket(struct nvme_tcp_queue *queue)
 		return -ENODEV;
 	}
 
-	if (!(netdev->features & NETIF_F_HW_TCP_DDP)) {
+	if (!(netdev->features & (NETIF_F_HW_TCP_DDP | NETIF_F_HW_TCP_DDP_CRC_RX))) {
 		dev_put(netdev);
 		return -EOPNOTSUPP;
 	}
@@ -344,6 +392,9 @@ int nvme_tcp_offload_socket(struct nvme_tcp_queue *queue)
 	if (netdev->features & NETIF_F_HW_TCP_DDP)
 		set_bit(NVME_TCP_Q_OFF_DDP, &queue->flags);
 
+	if (netdev->features & NETIF_F_HW_TCP_DDP_CRC_RX)
+		set_bit(NVME_TCP_Q_OFF_DDGST_RX, &queue->flags);
+
 	return ret;
 }
 
@@ -375,7 +426,7 @@ int nvme_tcp_offload_limits(struct nvme_tcp_queue *queue)
 		return -ENODEV;
 	}
 
-	if (netdev->features & NETIF_F_HW_TCP_DDP &&
+	if ((netdev->features & (NETIF_F_HW_TCP_DDP | NETIF_F_HW_TCP_DDP_CRC_RX)) &&
 	    netdev->tcp_ddp_ops &&
 	    netdev->tcp_ddp_ops->tcp_ddp_limits)
 		ret = netdev->tcp_ddp_ops->tcp_ddp_limits(netdev, &limits);
@@ -727,6 +778,7 @@ static void nvme_tcp_init_recv_ctx(struct nvme_tcp_queue *queue)
 	queue->pdu_offset = 0;
 	queue->data_remaining = -1;
 	queue->ddgst_remaining = 0;
+	queue->ddgst_valid = true;
 }
 
 static void nvme_tcp_error_recovery(struct nvme_ctrl *ctrl)
@@ -907,7 +959,8 @@ static int nvme_tcp_recv_pdu(struct nvme_tcp_queue *queue, struct sk_buff *skb,
 
 	u64 pdu_seq = TCP_SKB_CB(skb)->seq + *offset - queue->pdu_offset;
 
-	if (test_bit(NVME_TCP_Q_OFF_DDP, &queue->flags))
+	if (test_bit(NVME_TCP_Q_OFF_DDP, &queue->flags) ||
+	    test_bit(NVME_TCP_Q_OFF_DDGST_RX, &queue->flags))
 		nvme_tcp_resync_response(queue, pdu_seq);
 
 	ret = skb_copy_bits(skb, *offset,
@@ -976,6 +1029,8 @@ static int nvme_tcp_recv_data(struct nvme_tcp_queue *queue, struct sk_buff *skb,
 	struct nvme_tcp_request *req;
 	struct request *rq;
 
+	if (queue->data_digest && test_bit(NVME_TCP_Q_OFF_DDGST_RX, &queue->flags))
+		nvme_tcp_ddp_ddgst_update(queue, skb);
 	rq = blk_mq_tag_to_rq(nvme_tcp_tagset(queue), pdu->command_id);
 	if (!rq) {
 		dev_err(queue->ctrl->ctrl.device,
@@ -1013,15 +1068,17 @@ static int nvme_tcp_recv_data(struct nvme_tcp_queue *queue, struct sk_buff *skb,
 		recv_len = min_t(size_t, recv_len,
 				iov_iter_count(&req->iter));
 
-		if (test_bit(NVME_TCP_Q_OFF_DDP, &queue->flags)) {
-			if (queue->data_digest)
+		if (test_bit(NVME_TCP_Q_OFF_DDP, &queue->flags)) { 
+			if (queue->data_digest &&
+			    !test_bit(NVME_TCP_Q_OFF_DDGST_RX, &queue->flags))
 				ret = skb_ddp_copy_and_hash_datagram_iter(skb, *offset,
 						&req->iter, recv_len, queue->rcv_hash);
 			else
 				ret = skb_ddp_copy_datagram_iter(skb, *offset,
 						&req->iter, recv_len);
 		} else {
-			if (queue->data_digest)
+			if (queue->data_digest &&
+			    !test_bit(NVME_TCP_Q_OFF_DDGST_RX, &queue->flags))
 				ret = skb_copy_and_hash_datagram_iter(skb, *offset,
 						&req->iter, recv_len, queue->rcv_hash);
 			else
@@ -1043,7 +1100,6 @@ static int nvme_tcp_recv_data(struct nvme_tcp_queue *queue, struct sk_buff *skb,
 
 	if (!queue->data_remaining) {
 		if (queue->data_digest) {
-			nvme_tcp_ddgst_final(queue->rcv_hash, &queue->exp_ddgst);
 			queue->ddgst_remaining = NVME_TCP_DIGEST_LENGTH;
 		} else {
 			if (pdu->hdr.flags & NVME_TCP_F_DATA_SUCCESS) {
@@ -1064,8 +1120,12 @@ static int nvme_tcp_recv_ddgst(struct nvme_tcp_queue *queue,
 	char *ddgst = (char *)&queue->recv_ddgst;
 	size_t recv_len = min_t(size_t, *len, queue->ddgst_remaining);
 	off_t off = NVME_TCP_DIGEST_LENGTH - queue->ddgst_remaining;
+	bool offload_fail, offload_en;
+	struct request *rq = NULL;
 	int ret;
 
+	if (test_bit(NVME_TCP_Q_OFF_DDGST_RX, &queue->flags))
+		nvme_tcp_ddp_ddgst_update(queue, skb);
 	ret = skb_copy_bits(skb, *offset, &ddgst[off], recv_len);
 	if (unlikely(ret))
 		return ret;
@@ -1076,17 +1136,29 @@ static int nvme_tcp_recv_ddgst(struct nvme_tcp_queue *queue,
 	if (queue->ddgst_remaining)
 		return 0;
 
-	if (queue->recv_ddgst != queue->exp_ddgst) {
-		dev_err(queue->ctrl->ctrl.device,
-			"data digest error: recv %#x expected %#x\n",
-			le32_to_cpu(queue->recv_ddgst),
-			le32_to_cpu(queue->exp_ddgst));
-		return -EIO;
+	offload_fail = !nvme_tcp_ddp_ddgst_ok(queue);
+	offload_en = test_bit(NVME_TCP_Q_OFF_DDGST_RX, &queue->flags);
+	if (!offload_en || offload_fail) {
+		if (offload_en && offload_fail) { // software-fallback
+			rq = blk_mq_tag_to_rq(nvme_tcp_tagset(queue),
+					      pdu->command_id);
+			nvme_tcp_ddp_ddgst_recalc(queue->rcv_hash, rq);
+		}
+
+		nvme_tcp_ddgst_final(queue->rcv_hash, &queue->exp_ddgst);
+		if (queue->recv_ddgst != queue->exp_ddgst) {
+			dev_err(queue->ctrl->ctrl.device,
+				"data digest error: recv %#x expected %#x\n",
+				le32_to_cpu(queue->recv_ddgst),
+				le32_to_cpu(queue->exp_ddgst));
+			return -EIO;
+		}
 	}
 
 	if (pdu->hdr.flags & NVME_TCP_F_DATA_SUCCESS) {
-		struct request *rq = blk_mq_tag_to_rq(nvme_tcp_tagset(queue),
-						pdu->command_id);
+		if (!rq)
+			rq = blk_mq_tag_to_rq(nvme_tcp_tagset(queue),
+					      pdu->command_id);
 
 		nvme_tcp_end_request(rq, NVME_SC_SUCCESS);
 		queue->nr_cqe++;
@@ -1825,8 +1897,10 @@ static void __nvme_tcp_stop_queue(struct nvme_tcp_queue *queue)
 	nvme_tcp_restore_sock_calls(queue);
 	cancel_work_sync(&queue->io_work);
 
-	if (test_bit(NVME_TCP_Q_OFF_DDP, &queue->flags))
+	if (test_bit(NVME_TCP_Q_OFF_DDP, &queue->flags) ||
+	    test_bit(NVME_TCP_Q_OFF_DDGST_RX, &queue->flags))
 		nvme_tcp_unoffload_socket(queue);
+
 }
 
 static void nvme_tcp_stop_queue(struct nvme_ctrl *nctrl, int qid)
@@ -1953,8 +2027,6 @@ static int nvme_tcp_alloc_admin_queue(struct nvme_ctrl *ctrl)
 {
 	int ret;
 
-	to_tcp_ctrl(ctrl)->offloading_netdev = NULL;
-
 	ret = nvme_tcp_alloc_queue(ctrl, 0, NVME_AQ_DEPTH);
 	if (ret)
 		return ret;
-- 
2.24.1

[PATCH v2 net-next 09/21] nvme-tcp: Deal with netdevice DOWN events

[Boris Pismenny]

From: Or Gerlitz <ogerlitz@mellanox.com>

For ddp setup/teardown and resync, the offloading logic
uses HW resources at the NIC driver such as SQ and CQ.

These resources are destroyed when the netdevice does down
and hence we must stop using them before the NIC driver
destroys them.

Use netdevice notifier for that matter -- offloaded connections
are stopped before the stack continues to call the NIC driver
close ndo.

We use the existing recovery flow which has the advantage
of resuming the offload once the connection is re-set.

This also buys us proper handling for the UNREGISTER event
b/c our offloading starts in the UP state, and down is always
there between up to unregister.

Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: Ben Ben-Ishay <benishay@mellanox.com>
Signed-off-by: Yoray Zack <yorayz@mellanox.com>
---
 drivers/nvme/host/tcp.c | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index 09d2e2e529cd..f85d04346156 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -145,6 +145,7 @@ struct nvme_tcp_ctrl {
 
 static LIST_HEAD(nvme_tcp_ctrl_list);
 static DEFINE_MUTEX(nvme_tcp_ctrl_mutex);
+static struct notifier_block nvme_tcp_netdevice_nb;
 static struct workqueue_struct *nvme_tcp_wq;
 static const struct blk_mq_ops nvme_tcp_mq_ops;
 static const struct blk_mq_ops nvme_tcp_admin_mq_ops;
@@ -2913,6 +2914,27 @@ static struct nvme_ctrl *nvme_tcp_create_ctrl(struct device *dev,
 	return ERR_PTR(ret);
 }
 
+static int nvme_tcp_netdev_event(struct notifier_block *this,
+				 unsigned long event, void *ptr)
+{
+	struct net_device *ndev = netdev_notifier_info_to_dev(ptr);
+	struct nvme_tcp_ctrl *ctrl;
+
+	switch (event) {
+	case NETDEV_GOING_DOWN:
+		mutex_lock(&nvme_tcp_ctrl_mutex);
+		list_for_each_entry(ctrl, &nvme_tcp_ctrl_list, list) {
+			if (ndev != ctrl->offloading_netdev)
+				continue;
+			nvme_tcp_error_recovery(&ctrl->ctrl);
+		}
+		mutex_unlock(&nvme_tcp_ctrl_mutex);
+		flush_workqueue(nvme_reset_wq);
+		/* we assume that the going down part of error recovery is over */
+	}
+	return NOTIFY_DONE;
+}
+
 static struct nvmf_transport_ops nvme_tcp_transport = {
 	.name		= "tcp",
 	.module		= THIS_MODULE,
@@ -2927,13 +2949,26 @@ static struct nvmf_transport_ops nvme_tcp_transport = {
 
 static int __init nvme_tcp_init_module(void)
 {
+	int ret;
+
 	nvme_tcp_wq = alloc_workqueue("nvme_tcp_wq",
 			WQ_MEM_RECLAIM | WQ_HIGHPRI, 0);
 	if (!nvme_tcp_wq)
 		return -ENOMEM;
 
+	nvme_tcp_netdevice_nb.notifier_call = nvme_tcp_netdev_event;
+	ret = register_netdevice_notifier(&nvme_tcp_netdevice_nb);
+	if (ret) {
+		pr_err("failed to register netdev notifier\n");
+		goto out_err_reg_notifier;
+	}
+
 	nvmf_register_transport(&nvme_tcp_transport);
 	return 0;
+
+out_err_reg_notifier:
+	destroy_workqueue(nvme_tcp_wq);
+	return ret;
 }
 
 static void __exit nvme_tcp_cleanup_module(void)
@@ -2941,6 +2976,7 @@ static void __exit nvme_tcp_cleanup_module(void)
 	struct nvme_tcp_ctrl *ctrl;
 
 	nvmf_unregister_transport(&nvme_tcp_transport);
+	unregister_netdevice_notifier(&nvme_tcp_netdevice_nb);
 
 	mutex_lock(&nvme_tcp_ctrl_mutex);
 	list_for_each_entry(ctrl, &nvme_tcp_ctrl_list, list)
-- 
2.24.1

[PATCH v2 net-next 10/21] net/mlx5: Header file changes for nvme-tcp offload

[Boris Pismenny]

From: Ben Ben-ishay <benishay@nvidia.com>

Add the necessary infrastructure for NVMEoTCP offload:

- Add nvmeocp_en + nvmeotcp_crc_en bit to the TIR for identify NVMEoTCP offload flow
  And tag_buffer_id that will be used by the connected nvmeotcp_queues
- Add new CQE field that will be used to pass scattered data information to SW
- Add new capability to HCA_CAP that represnts the NVMEoTCP offload ability

Signed-off-by: Ben Ben-ishay <benishay@nvidia.com>
Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Yoray Zack <yorayz@mellanox.com>
---
 include/linux/mlx5/device.h   |   8 +++
 include/linux/mlx5/mlx5_ifc.h | 101 +++++++++++++++++++++++++++++++++-
 include/linux/mlx5/qp.h       |   1 +
 3 files changed, 107 insertions(+), 3 deletions(-)

diff --git a/include/linux/mlx5/device.h b/include/linux/mlx5/device.h
index 00057eae89ab..4433ff213d32 100644
--- a/include/linux/mlx5/device.h
+++ b/include/linux/mlx5/device.h
@@ -263,6 +263,7 @@ enum {
 enum {
 	MLX5_MKEY_MASK_LEN		= 1ull << 0,
 	MLX5_MKEY_MASK_PAGE_SIZE	= 1ull << 1,
+	MLX5_MKEY_MASK_XLT_OCT_SIZE     = 1ull << 2,
 	MLX5_MKEY_MASK_START_ADDR	= 1ull << 6,
 	MLX5_MKEY_MASK_PD		= 1ull << 7,
 	MLX5_MKEY_MASK_EN_RINVAL	= 1ull << 8,
@@ -1171,6 +1172,7 @@ enum mlx5_cap_type {
 	MLX5_CAP_VDPA_EMULATION = 0x13,
 	MLX5_CAP_DEV_EVENT = 0x14,
 	MLX5_CAP_IPSEC,
+	MLX5_CAP_DEV_NVMEOTCP = 0x19,
 	/* NUM OF CAP Types */
 	MLX5_CAP_NUM
 };
@@ -1391,6 +1393,12 @@ enum mlx5_qcam_feature_groups {
 #define MLX5_CAP_IPSEC(mdev, cap)\
 	MLX5_GET(ipsec_cap, (mdev)->caps.hca_cur[MLX5_CAP_IPSEC], cap)
 
+#define MLX5_CAP_DEV_NVMEOTCP(mdev, cap)\
+	MLX5_GET(nvmeotcp_cap, mdev->caps.hca_cur[MLX5_CAP_DEV_NVMEOTCP], cap)
+
+#define MLX5_CAP64_NVMEOTCP(mdev, cap)\
+	MLX5_GET64(nvmeotcp_cap, mdev->caps.hca_cur[MLX5_CAP_DEV_NVMEOTCP], cap)
+
 enum {
 	MLX5_CMD_STAT_OK			= 0x0,
 	MLX5_CMD_STAT_INT_ERR			= 0x1,
diff --git a/include/linux/mlx5/mlx5_ifc.h b/include/linux/mlx5/mlx5_ifc.h
index ec0d01e26b3e..923f8961d50d 100644
--- a/include/linux/mlx5/mlx5_ifc.h
+++ b/include/linux/mlx5/mlx5_ifc.h
@@ -1271,7 +1271,9 @@ struct mlx5_ifc_cmd_hca_cap_bits {
 	u8         log_max_srq_sz[0x8];
 	u8         log_max_qp_sz[0x8];
 	u8         event_cap[0x1];
-	u8         reserved_at_91[0x7];
+	u8         reserved_at_91[0x5];
+	u8         nvmeotcp[0x1];
+	u8         reserved_at_97[0x1];
 	u8         prio_tag_required[0x1];
 	u8         reserved_at_99[0x2];
 	u8         log_max_qp[0x5];
@@ -3020,6 +3022,21 @@ struct mlx5_ifc_roce_addr_layout_bits {
 	u8         reserved_at_e0[0x20];
 };
 
+struct mlx5_ifc_nvmeotcp_cap_bits {
+	u8    zerocopy[0x1];
+	u8    crc_rx[0x1];
+	u8    crc_tx[0x1];
+	u8    reserved_at_3[0x15];
+	u8    version[0x8];
+
+	u8    reserved_at_20[0x13];
+	u8    log_max_nvmeotcp_tag_buffer_table[0x5];
+	u8    reserved_at_38[0x3];
+	u8    log_max_nvmeotcp_tag_buffer_size[0x5];
+
+	u8    reserved_at_40[0x7c0];
+};
+
 union mlx5_ifc_hca_cap_union_bits {
 	struct mlx5_ifc_cmd_hca_cap_bits cmd_hca_cap;
 	struct mlx5_ifc_odp_cap_bits odp_cap;
@@ -3036,6 +3053,7 @@ union mlx5_ifc_hca_cap_union_bits {
 	struct mlx5_ifc_tls_cap_bits tls_cap;
 	struct mlx5_ifc_device_mem_cap_bits device_mem_cap;
 	struct mlx5_ifc_virtio_emulation_cap_bits virtio_emulation_cap;
+	struct mlx5_ifc_nvmeotcp_cap_bits nvmeotcp_cap;
 	u8         reserved_at_0[0x8000];
 };
 
@@ -3230,7 +3248,9 @@ struct mlx5_ifc_tirc_bits {
 
 	u8         disp_type[0x4];
 	u8         tls_en[0x1];
-	u8         reserved_at_25[0x1b];
+	u8         nvmeotcp_zero_copy_en[0x1];
+	u8         nvmeotcp_crc_en[0x1];
+	u8         reserved_at_27[0x19];
 
 	u8         reserved_at_40[0x40];
 
@@ -3261,7 +3281,8 @@ struct mlx5_ifc_tirc_bits {
 
 	struct mlx5_ifc_rx_hash_field_select_bits rx_hash_field_selector_inner;
 
-	u8         reserved_at_2c0[0x4c0];
+	u8         nvmeotcp_tag_buffer_table_id[0x20];
+	u8         reserved_at_2e0[0x4a0];
 };
 
 enum {
@@ -10716,12 +10737,14 @@ enum {
 	MLX5_HCA_CAP_GENERAL_OBJECT_TYPES_ENCRYPTION_KEY = BIT_ULL(0xc),
 	MLX5_HCA_CAP_GENERAL_OBJECT_TYPES_IPSEC = BIT_ULL(0x13),
 	MLX5_HCA_CAP_GENERAL_OBJECT_TYPES_SAMPLER = BIT_ULL(0x20),
+	MLX5_HCA_CAP_GENERAL_OBJECT_TYPES_NVMEOTCP_TAG_BUFFER_TABLE = BIT_ULL(0x21),
 };
 
 enum {
 	MLX5_GENERAL_OBJECT_TYPES_ENCRYPTION_KEY = 0xc,
 	MLX5_GENERAL_OBJECT_TYPES_IPSEC = 0x13,
 	MLX5_GENERAL_OBJECT_TYPES_SAMPLER = 0x20,
+	MLX5_GENERAL_OBJECT_TYPES_NVMEOTCP_TAG_BUFFER_TABLE = 0x21
 };
 
 enum {
@@ -10823,6 +10846,20 @@ struct mlx5_ifc_create_sampler_obj_in_bits {
 	struct mlx5_ifc_sampler_obj_bits sampler_object;
 };
 
+struct mlx5_ifc_nvmeotcp_tag_buf_table_obj_bits {
+	u8    modify_field_select[0x40];
+
+	u8    reserved_at_20[0x20];
+
+	u8    reserved_at_40[0x1b];
+	u8    log_tag_buffer_table_size[0x5];
+};
+
+struct mlx5_ifc_create_nvmeotcp_tag_buf_table_in_bits {
+	struct mlx5_ifc_general_obj_in_cmd_hdr_bits general_obj_in_cmd_hdr;
+	struct mlx5_ifc_nvmeotcp_tag_buf_table_obj_bits nvmeotcp_tag_buf_table_obj;
+};
+
 enum {
 	MLX5_GENERAL_OBJECT_TYPE_ENCRYPTION_KEY_KEY_SIZE_128 = 0x0,
 	MLX5_GENERAL_OBJECT_TYPE_ENCRYPTION_KEY_KEY_SIZE_256 = 0x1,
@@ -10833,6 +10870,18 @@ enum {
 	MLX5_GENERAL_OBJECT_TYPE_ENCRYPTION_KEY_TYPE_IPSEC = 0x2,
 };
 
+enum {
+	MLX5_TRANSPORT_STATIC_PARAMS_ACC_TYPE_XTS               = 0x0,
+	MLX5_TRANSPORT_STATIC_PARAMS_ACC_TYPE_TLS               = 0x1,
+	MLX5_TRANSPORT_STATIC_PARAMS_ACC_TYPE_NVMETCP           = 0x2,
+	MLX5_TRANSPORT_STATIC_PARAMS_ACC_TYPE_NVMETCP_WITH_TLS  = 0x3,
+};
+
+enum {
+	MLX5_TRANSPORT_STATIC_PARAMS_TI_INITIATOR  = 0x0,
+	MLX5_TRANSPORT_STATIC_PARAMS_TI_TARGET     = 0x1,
+};
+
 struct mlx5_ifc_tls_static_params_bits {
 	u8         const_2[0x2];
 	u8         tls_version[0x4];
@@ -10873,4 +10922,50 @@ enum {
 	MLX5_MTT_PERM_RW	= MLX5_MTT_PERM_READ | MLX5_MTT_PERM_WRITE,
 };
 
+struct mlx5_ifc_nvmeotcp_progress_params_bits {
+	u8    next_pdu_tcp_sn[0x20];
+
+	u8    hw_resync_tcp_sn[0x20];
+
+	u8    pdu_tracker_state[0x2];
+	u8    offloading_state[0x2];
+	u8    reserved_at_64[0xc];
+	u8    cccid_ttag[0x10];
+};
+
+struct mlx5_ifc_transport_static_params_bits {
+	u8    const_2[0x2];
+	u8    tls_version[0x4];
+	u8    const_1[0x2];
+	u8    reserved_at_8[0x14];
+	u8    acc_type[0x4];
+
+	u8    reserved_at_20[0x20];
+
+	u8    initial_record_number[0x40];
+
+	u8    resync_tcp_sn[0x20];
+
+	u8    gcm_iv[0x20];
+
+	u8    implicit_iv[0x40];
+
+	u8    reserved_at_100[0x8];
+	u8    dek_index[0x18];
+
+	u8    reserved_at_120[0x14];
+	u8    const1[0x1];
+	u8    ti[0x1];
+	u8    zero_copy_en[0x1];
+	u8    ddgst_offload_en[0x1];
+	u8    hdgst_offload_en[0x1];
+	u8    ddgst_en[0x1];
+	u8    hddgst_en[0x1];
+	u8    pda[0x5];
+
+	u8    nvme_resync_tcp_sn[0x20];
+
+	u8    reserved_at_160[0xa0];
+};
+
 #endif /* MLX5_IFC_H */
diff --git a/include/linux/mlx5/qp.h b/include/linux/mlx5/qp.h
index d75ef8aa8fac..5fa8b82c9edb 100644
--- a/include/linux/mlx5/qp.h
+++ b/include/linux/mlx5/qp.h
@@ -220,6 +220,7 @@ struct mlx5_wqe_ctrl_seg {
 #define MLX5_WQE_CTRL_OPCODE_MASK 0xff
 #define MLX5_WQE_CTRL_WQE_INDEX_MASK 0x00ffff00
 #define MLX5_WQE_CTRL_WQE_INDEX_SHIFT 8
+#define MLX5_WQE_CTRL_TIR_TIS_INDEX_SHIFT 8
 
 enum {
 	MLX5_ETH_WQE_L3_INNER_CSUM      = 1 << 4,
-- 
2.24.1

[PATCH v2 net-next 11/21] net/mlx5: Add 128B CQE for NVMEoTCP offload

[Boris Pismenny]

From: Ben Ben-ishay <benishay@nvidia.com>

Add the NVMEoTCP offload definition and access functions for 128B CQEs.

Signed-off-by: Ben Ben-ishay <benishay@nvidia.com>
Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Yoray Zack <yorayz@mellanox.com>
---
 include/linux/mlx5/device.h | 36 +++++++++++++++++++++++++++++++++++-
 1 file changed, 35 insertions(+), 1 deletion(-)

diff --git a/include/linux/mlx5/device.h b/include/linux/mlx5/device.h
index 4433ff213d32..f4912d6c42f8 100644
--- a/include/linux/mlx5/device.h
+++ b/include/linux/mlx5/device.h
@@ -791,7 +791,7 @@ struct mlx5_err_cqe {
 
 struct mlx5_cqe64 {
 	u8		tls_outer_l3_tunneled;
-	u8		rsvd0;
+	u8		nvmetcp;
 	__be16		wqe_id;
 	u8		lro_tcppsh_abort_dupack;
 	u8		lro_min_ttl;
@@ -824,6 +824,19 @@ struct mlx5_cqe64 {
 	u8		op_own;
 };
 
+struct mlx5e_cqe128 {
+	__be16		cclen;
+	__be16		hlen;
+	union {
+		__be32		resync_tcp_sn;
+		__be32		ccoff;
+	};
+	__be16		ccid;
+	__be16		rsvd8;
+	u8		rsvd12[52];
+	struct mlx5_cqe64 cqe64;
+};
+
 struct mlx5_mini_cqe8 {
 	union {
 		__be32 rx_hash_result;
@@ -854,6 +867,27 @@ enum {
 
 #define MLX5_MINI_CQE_ARRAY_SIZE 8
 
+static inline bool cqe_is_nvmeotcp_resync(struct mlx5_cqe64 *cqe)
+{
+	return ((cqe->nvmetcp >> 6) & 0x1);
+}
+
+static inline bool cqe_is_nvmeotcp_crcvalid(struct mlx5_cqe64 *cqe)
+{
+	return ((cqe->nvmetcp >> 5) & 0x1);
+}
+
+static inline bool cqe_is_nvmeotcp_zc(struct mlx5_cqe64 *cqe)
+{
+	return ((cqe->nvmetcp >> 4) & 0x1);
+}
+
+/* check if cqe is zc or crc or resync */
+static inline bool cqe_is_nvmeotcp(struct mlx5_cqe64 *cqe)
+{
+	return ((cqe->nvmetcp >> 4) & 0x7);
+}
+
 static inline u8 mlx5_get_cqe_format(struct mlx5_cqe64 *cqe)
 {
 	return (cqe->op_own >> 2) & 0x3;
-- 
2.24.1

[PATCH v2 net-next 12/21] net/mlx5e: TCP flow steering for nvme-tcp

[Boris Pismenny]

Both nvme-tcp and tls require tcp flow steering. Compile it for both of
them. Additionally, use reference counting to allocate/free TCP flow
steering.

Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: Ben Ben-Ishay <benishay@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Yoray Zack <yorayz@mellanox.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/en/fs.h        |  4 ++--
 .../net/ethernet/mellanox/mlx5/core/en_accel/fs_tcp.c  | 10 ++++++++++
 .../net/ethernet/mellanox/mlx5/core/en_accel/fs_tcp.h  |  2 +-
 3 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/fs.h b/drivers/net/ethernet/mellanox/mlx5/core/en/fs.h
index a16297e7e2ac..a7fe3a6358ea 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/fs.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/fs.h
@@ -137,7 +137,7 @@ enum {
 	MLX5E_L2_FT_LEVEL,
 	MLX5E_TTC_FT_LEVEL,
 	MLX5E_INNER_TTC_FT_LEVEL,
-#ifdef CONFIG_MLX5_EN_TLS
+#if defined(CONFIG_MLX5_EN_TLS) || defined(CONFIG_MLX5_EN_NVMEOTCP)
 	MLX5E_ACCEL_FS_TCP_FT_LEVEL,
 #endif
 #ifdef CONFIG_MLX5_EN_ARFS
@@ -256,7 +256,7 @@ struct mlx5e_flow_steering {
 #ifdef CONFIG_MLX5_EN_ARFS
 	struct mlx5e_arfs_tables        arfs;
 #endif
-#ifdef CONFIG_MLX5_EN_TLS
+#if defined(CONFIG_MLX5_EN_TLS) || defined(CONFIG_MLX5_EN_NVMEOTCP)
 	struct mlx5e_accel_fs_tcp      *accel_tcp;
 #endif
 };
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/fs_tcp.c b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/fs_tcp.c
index e51f60b55daa..21341a92f355 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/fs_tcp.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/fs_tcp.c
@@ -14,6 +14,7 @@ enum accel_fs_tcp_type {
 struct mlx5e_accel_fs_tcp {
 	struct mlx5e_flow_table tables[ACCEL_FS_TCP_NUM_TYPES];
 	struct mlx5_flow_handle *default_rules[ACCEL_FS_TCP_NUM_TYPES];
+	refcount_t		ref_count;
 };
 
 static enum mlx5e_traffic_types fs_accel2tt(enum accel_fs_tcp_type i)
@@ -337,6 +338,7 @@ static int accel_fs_tcp_enable(struct mlx5e_priv *priv)
 			return err;
 		}
 	}
+	refcount_set(&priv->fs.accel_tcp->ref_count, 1);
 	return 0;
 }
 
@@ -360,6 +362,9 @@ void mlx5e_accel_fs_tcp_destroy(struct mlx5e_priv *priv)
 	if (!priv->fs.accel_tcp)
 		return;
 
+	if (!refcount_dec_and_test(&priv->fs.accel_tcp->ref_count))
+		return;
+
 	accel_fs_tcp_disable(priv);
 
 	for (i = 0; i < ACCEL_FS_TCP_NUM_TYPES; i++)
@@ -376,6 +381,11 @@ int mlx5e_accel_fs_tcp_create(struct mlx5e_priv *priv)
 	if (!MLX5_CAP_FLOWTABLE_NIC_RX(priv->mdev, ft_field_support.outer_ip_version))
 		return -EOPNOTSUPP;
 
+	if (priv->fs.accel_tcp) {
+		refcount_inc(&priv->fs.accel_tcp->ref_count);
+		return 0;
+	}
+
 	priv->fs.accel_tcp = kzalloc(sizeof(*priv->fs.accel_tcp), GFP_KERNEL);
 	if (!priv->fs.accel_tcp)
 		return -ENOMEM;
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/fs_tcp.h b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/fs_tcp.h
index 589235824543..8aff9298183c 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/fs_tcp.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/fs_tcp.h
@@ -6,7 +6,7 @@
 
 #include "en.h"
 
-#ifdef CONFIG_MLX5_EN_TLS
+#if defined(CONFIG_MLX5_EN_TLS) || defined(CONFIG_MLX5_EN_NVMEOTCP)
 int mlx5e_accel_fs_tcp_create(struct mlx5e_priv *priv);
 void mlx5e_accel_fs_tcp_destroy(struct mlx5e_priv *priv);
 struct mlx5_flow_handle *mlx5e_accel_fs_add_sk(struct mlx5e_priv *priv,
-- 
2.24.1

[PATCH v2 net-next 13/21] net/mlx5e: NVMEoTCP offload initialization

[Boris Pismenny]

From: Ben Ben-Ishay <benishay@nvidia.com>

This commit introduce the initialization blocks for NVMEoTCP offload:
- Use 128B CQEs when NVME-TCP offload is enabled.
- Use a dedicated icosq for NVME-TCP work. This list of SQ is unique in the
  sense that it is driven directly by the NVME-TCP layer to submit and
  invalidate ddp requests.
- Query nvmeotcp capabilities

Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: Ben Ben-Ishay <benishay@nvidia.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Yoray Zack <yorayz@mellanox.com>
---
 .../net/ethernet/mellanox/mlx5/core/Kconfig   |  11 +
 .../net/ethernet/mellanox/mlx5/core/Makefile  |   2 +
 drivers/net/ethernet/mellanox/mlx5/core/en.h  |   7 +
 .../ethernet/mellanox/mlx5/core/en/params.h   |   1 +
 .../mellanox/mlx5/core/en_accel/en_accel.h    |   9 +-
 .../mellanox/mlx5/core/en_accel/nvmeotcp.c    | 196 ++++++++++++++++++
 .../mellanox/mlx5/core/en_accel/nvmeotcp.h    | 115 ++++++++++
 .../net/ethernet/mellanox/mlx5/core/en_main.c |  39 +++-
 .../net/ethernet/mellanox/mlx5/core/en_txrx.c |  17 ++
 drivers/net/ethernet/mellanox/mlx5/core/fw.c  |   6 +
 10 files changed, 401 insertions(+), 2 deletions(-)
 create mode 100644 drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.c
 create mode 100644 drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.h

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/Kconfig b/drivers/net/ethernet/mellanox/mlx5/core/Kconfig
index ad45d20f9d44..02b4066f54e6 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/Kconfig
+++ b/drivers/net/ethernet/mellanox/mlx5/core/Kconfig
@@ -222,3 +222,14 @@ config MLX5_SF_MANAGER
 	port is managed through devlink.  A subfunction supports RDMA, netdevice
 	and vdpa device. It is similar to a SRIOV VF but it doesn't require
 	SRIOV support.
+
+config MLX5_EN_NVMEOTCP
+	bool "NVMEoTCP accelaration"
+	depends on MLX5_CORE_EN
+	depends on TCP_DDP
+	depends on TCP_DDP_CRC
+	default y
+	help
+	Build support for NVMEoTCP accelaration in the NIC.
+	Note: Support for hardware with this capability needs to be selected
+	for this option to become available.
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/Makefile b/drivers/net/ethernet/mellanox/mlx5/core/Makefile
index 59ed3c39c8c3..ada8cd22f8fb 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/Makefile
+++ b/drivers/net/ethernet/mellanox/mlx5/core/Makefile
@@ -96,3 +96,5 @@ mlx5_core-$(CONFIG_MLX5_SF) += sf/vhca_event.o sf/dev/dev.o sf/dev/driver.o
 # SF manager
 #
 mlx5_core-$(CONFIG_MLX5_SF_MANAGER) += sf/cmd.o sf/hw_table.o sf/devlink.o
+
+mlx5_core-$(CONFIG_MLX5_EN_NVMEOTCP) += en_accel/fs_tcp.o en_accel/nvmeotcp.o
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en.h b/drivers/net/ethernet/mellanox/mlx5/core/en.h
index 01c8115caa64..ff100c290b59 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en.h
@@ -664,6 +664,10 @@ struct mlx5e_channel {
 	struct mlx5e_xdpsq         rq_xdpsq;
 	struct mlx5e_txqsq         sq[MLX5E_MAX_NUM_TC];
 	struct mlx5e_icosq         icosq;   /* internal control operations */
+#ifdef CONFIG_MLX5_EN_NVMEOTCP
+	struct list_head	   list_nvmeotcpsq;   /* nvmeotcp umrs  */
+	spinlock_t                 nvmeotcp_icosq_lock;
+#endif
 	bool                       xdp;
 	struct napi_struct         napi;
 	struct device             *pdev;
@@ -856,6 +860,9 @@ struct mlx5e_priv {
 #endif
 #ifdef CONFIG_MLX5_EN_TLS
 	struct mlx5e_tls          *tls;
+#endif
+#ifdef CONFIG_MLX5_EN_NVMEOTCP
+	struct mlx5e_nvmeotcp      *nvmeotcp;
 #endif
 	struct devlink_health_reporter *tx_reporter;
 	struct devlink_health_reporter *rx_reporter;
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/params.h b/drivers/net/ethernet/mellanox/mlx5/core/en/params.h
index 807147d97a0f..20e9e5e81ae7 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/params.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/params.h
@@ -16,6 +16,7 @@ struct mlx5e_cq_param {
 	struct mlx5_wq_param       wq;
 	u16                        eq_ix;
 	u8                         cq_period_mode;
+	bool                       force_cqe128;
 };
 
 struct mlx5e_rq_param {
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/en_accel.h b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/en_accel.h
index fb89b24deb2b..98728f7404ec 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/en_accel.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/en_accel.h
@@ -39,6 +39,7 @@
 #include "en_accel/ipsec_rxtx.h"
 #include "en_accel/tls.h"
 #include "en_accel/tls_rxtx.h"
+#include "en_accel/nvmeotcp.h"
 #include "en.h"
 #include "en/txrx.h"
 
@@ -196,11 +197,17 @@ static inline void mlx5e_accel_tx_finish(struct mlx5e_txqsq *sq,
 
 static inline int mlx5e_accel_init_rx(struct mlx5e_priv *priv)
 {
-	return mlx5e_ktls_init_rx(priv);
+	int tls, nvmeotcp;
+
+	tls = mlx5e_ktls_init_rx(priv);
+	nvmeotcp = mlx5e_nvmeotcp_init_rx(priv);
+
+	return tls && nvmeotcp;
 }
 
 static inline void mlx5e_accel_cleanup_rx(struct mlx5e_priv *priv)
 {
+	mlx5e_nvmeotcp_cleanup_rx(priv);
 	mlx5e_ktls_cleanup_rx(priv);
 }
 #endif /* __MLX5E_EN_ACCEL_H__ */
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.c b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.c
new file mode 100644
index 000000000000..0834deb7a3ac
--- /dev/null
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.c
@@ -0,0 +1,196 @@
+// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
+/* Copyright (c) 2021 Mellanox Technologies. */
+
+#include <linux/netdevice.h>
+#include <linux/idr.h>
+#include "en_accel/nvmeotcp.h"
+#include "en_accel/fs_tcp.h"
+#include "en/txrx.h"
+
+#define MAX_NVMEOTCP_QUEUES	(512)
+#define MIN_NVMEOTCP_QUEUES	(1)
+
+static const struct rhashtable_params rhash_queues = {
+	.key_len = sizeof(int),
+	.key_offset = offsetof(struct mlx5e_nvmeotcp_queue, id),
+	.head_offset = offsetof(struct mlx5e_nvmeotcp_queue, hash),
+	.automatic_shrinking = true,
+	.min_size = 1,
+	.max_size = MAX_NVMEOTCP_QUEUES,
+};
+
+static int
+mlx5e_nvmeotcp_offload_limits(struct net_device *netdev,
+			      struct tcp_ddp_limits *limits)
+{
+	return 0;
+}
+
+static int
+mlx5e_nvmeotcp_queue_init(struct net_device *netdev,
+			  struct sock *sk,
+			  struct tcp_ddp_config *tconfig)
+{
+	return 0;
+}
+
+static void
+mlx5e_nvmeotcp_queue_teardown(struct net_device *netdev,
+			      struct sock *sk)
+{
+}
+
+static int
+mlx5e_nvmeotcp_ddp_setup(struct net_device *netdev,
+			 struct sock *sk,
+			 struct tcp_ddp_io *ddp)
+{
+	return 0;
+}
+
+static int
+mlx5e_nvmeotcp_ddp_teardown(struct net_device *netdev,
+			    struct sock *sk,
+			    struct tcp_ddp_io *ddp,
+			    void *ddp_ctx)
+{
+	return 0;
+}
+
+static void
+mlx5e_nvmeotcp_dev_resync(struct net_device *netdev,
+			  struct sock *sk, u32 seq)
+{
+}
+
+static const struct tcp_ddp_dev_ops mlx5e_nvmeotcp_ops = {
+	.tcp_ddp_limits = mlx5e_nvmeotcp_offload_limits,
+	.tcp_ddp_sk_add = mlx5e_nvmeotcp_queue_init,
+	.tcp_ddp_sk_del = mlx5e_nvmeotcp_queue_teardown,
+	.tcp_ddp_setup = mlx5e_nvmeotcp_ddp_setup,
+	.tcp_ddp_teardown = mlx5e_nvmeotcp_ddp_teardown,
+	.tcp_ddp_resync = mlx5e_nvmeotcp_dev_resync,
+};
+
+int set_feature_nvme_tcp(struct net_device *netdev, bool enable)
+{
+	struct mlx5e_priv *priv = netdev_priv(netdev);
+	int err = 0;
+
+	mutex_lock(&priv->state_lock);
+	if (enable)
+		err = mlx5e_accel_fs_tcp_create(priv);
+	else
+		mlx5e_accel_fs_tcp_destroy(priv);
+	mutex_unlock(&priv->state_lock);
+	if (err)
+		return err;
+
+	priv->nvmeotcp->enable = enable;
+	err = mlx5e_safe_reopen_channels(priv);
+	return err;
+}
+
+int set_feature_nvme_tcp_crc(struct net_device *netdev, bool enable)
+{
+	struct mlx5e_priv *priv = netdev_priv(netdev);
+	int err = 0;
+
+	mutex_lock(&priv->state_lock);
+	if (enable)
+		err = mlx5e_accel_fs_tcp_create(priv);
+	else
+		mlx5e_accel_fs_tcp_destroy(priv);
+	mutex_unlock(&priv->state_lock);
+
+	priv->nvmeotcp->crc_rx_enable = enable;
+	err = mlx5e_safe_reopen_channels(priv);
+	if (err)
+		netdev_err(priv->netdev,
+			   "%s failed to reopen channels, err(%d).\n",
+			   __func__, err);
+
+	return err;
+}
+
+void mlx5e_nvmeotcp_build_netdev(struct mlx5e_priv *priv)
+{
+	struct net_device *netdev = priv->netdev;
+
+	if (!MLX5_CAP_GEN(priv->mdev, nvmeotcp))
+		return;
+
+	if (MLX5_CAP_DEV_NVMEOTCP(priv->mdev, zerocopy)) {
+		netdev->features |= NETIF_F_HW_TCP_DDP;
+		netdev->hw_features |= NETIF_F_HW_TCP_DDP;
+	}
+
+	if (MLX5_CAP_DEV_NVMEOTCP(priv->mdev, crc_rx)) {
+		netdev->features |= NETIF_F_HW_TCP_DDP_CRC_RX;
+		netdev->hw_features |= NETIF_F_HW_TCP_DDP_CRC_RX;
+	}
+
+	netdev->tcp_ddp_ops = &mlx5e_nvmeotcp_ops;
+	priv->nvmeotcp->enable = true;
+}
+
+int mlx5e_nvmeotcp_init_rx(struct mlx5e_priv *priv)
+{
+	int ret = 0;
+
+	if (priv->netdev->features & NETIF_F_HW_TCP_DDP) {
+		ret = mlx5e_accel_fs_tcp_create(priv);
+		if (ret)
+			return ret;
+	}
+
+	if (priv->netdev->features & NETIF_F_HW_TCP_DDP_CRC_RX)
+		ret = mlx5e_accel_fs_tcp_create(priv);
+
+	return ret;
+}
+
+void mlx5e_nvmeotcp_cleanup_rx(struct mlx5e_priv *priv)
+{
+	if (priv->netdev->features & NETIF_F_HW_TCP_DDP)
+		mlx5e_accel_fs_tcp_destroy(priv);
+
+	if (priv->netdev->features & NETIF_F_HW_TCP_DDP_CRC_RX)
+		mlx5e_accel_fs_tcp_destroy(priv);
+}
+
+int mlx5e_nvmeotcp_init(struct mlx5e_priv *priv)
+{
+	struct mlx5e_nvmeotcp *nvmeotcp = kzalloc(sizeof(*nvmeotcp), GFP_KERNEL);
+	int ret = 0;
+
+	if (!nvmeotcp)
+		return -ENOMEM;
+
+	ida_init(&nvmeotcp->queue_ids);
+	ret = rhashtable_init(&nvmeotcp->queue_hash, &rhash_queues);
+	if (ret)
+		goto err_ida;
+
+	priv->nvmeotcp = nvmeotcp;
+	goto out;
+
+err_ida:
+	ida_destroy(&nvmeotcp->queue_ids);
+	kfree(nvmeotcp);
+out:
+	return ret;
+}
+
+void mlx5e_nvmeotcp_cleanup(struct mlx5e_priv *priv)
+{
+	struct mlx5e_nvmeotcp *nvmeotcp = priv->nvmeotcp;
+
+	if (!nvmeotcp)
+		return;
+
+	rhashtable_destroy(&nvmeotcp->queue_hash);
+	ida_destroy(&nvmeotcp->queue_ids);
+	kfree(nvmeotcp);
+	priv->nvmeotcp = NULL;
+}
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.h b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.h
new file mode 100644
index 000000000000..753757fc44a3
--- /dev/null
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.h
@@ -0,0 +1,115 @@
+/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
+/* Copyright (c) 2021 Mellanox Technologies. */
+#ifndef __MLX5E_NVMEOTCP_H__
+#define __MLX5E_NVMEOTCP_H__
+
+#ifdef CONFIG_MLX5_EN_NVMEOTCP
+
+#include "net/tcp_ddp.h"
+#include "en.h"
+#include "en/params.h"
+
+struct nvmeotcp_queue_entry {
+	struct mlx5e_nvmeotcp_queue	*queue;
+	u32				sgl_length;
+	struct mlx5_core_mkey		klm_mkey;
+	struct scatterlist		*sgl;
+	u32				ccid_gen;
+	u64				size;
+
+	/* for the ddp invalidate done callback */
+	void				*ddp_ctx;
+	struct tcp_ddp_io		*ddp;
+};
+
+struct mlx5e_nvmeotcp_sq {
+	struct list_head		list;
+	struct mlx5e_icosq		icosq;
+};
+
+/**
+ *	struct mlx5e_nvmeotcp_queue - MLX5 metadata for NVMEoTCP queue
+ *	@fh: Flow handle representing the 5-tuple steering for this flow
+ *	@tirn: Destination TIR number created for NVMEoTCP offload
+ *	@id: Flow tag ID used to identify this queue
+ *	@size: NVMEoTCP queue depth
+ *	@sq: Send queue used for sending control messages
+ *	@ccid_table: Table holding metadata for each CC
+ *	@tag_buf_table_id: Tag buffer table for CCIDs
+ *	@hash: Hash table of queues mapped by @id
+ *	@ref_count: Reference count for this structure
+ *	@ccoff: Offset within the current CC
+ *	@pda: Padding alignment
+ *	@ccid_gen: Generation ID for the CCID, used to avoid conflicts in DDP
+ *	@max_klms_per_wqe: Number of KLMs per DDP operation
+ *	@channel_ix: Channel IX for this nvmeotcp_queue
+ *	@sk: The socket used by the NVMe-TCP queue
+ *	@zerocopy: if this queue is used for zerocopy offload.
+ *	@crc_rx: if this queue is used for CRC Rx offload.
+ *	@ccid: ID of the current CC
+ *	@ccsglidx: Index within the scatter-gather list (SGL) of the current CC
+ *	@ccoff_inner: Current offset within the @ccsglidx element
+ *	@priv: mlx5e netdev priv
+ *	@inv_done: invalidate callback of the nvme tcp driver
+ *	@after_resync_cqe: indicate if resync occurred
+ */
+struct mlx5e_nvmeotcp_queue {
+	struct tcp_ddp_ctx		tcp_ddp_ctx;
+	struct mlx5_flow_handle		*fh;
+	int				tirn;
+	int				id;
+	u32				size;
+	struct mlx5e_nvmeotcp_sq	*sq;
+	struct nvmeotcp_queue_entry	*ccid_table;
+	u32				tag_buf_table_id;
+	struct rhash_head		hash;
+	refcount_t			ref_count;
+	bool				dgst;
+	int				pda;
+	u32				ccid_gen;
+	u32				max_klms_per_wqe;
+	u32				channel_ix;
+	struct sock			*sk;
+	bool				zerocopy;
+	bool				crc_rx;
+
+	/* current ccid fields */
+	off_t				ccoff;
+	int				ccid;
+	int				ccsglidx;
+	int				ccoff_inner;
+
+	/* for ddp invalidate flow */
+	struct mlx5e_priv		*priv;
+
+	/* for flow_steering flow */
+	struct completion		done;
+	/* for MASK HW resync cqe */
+	bool				after_resync_cqe;
+};
+
+struct mlx5e_nvmeotcp {
+	struct ida			queue_ids;
+	struct rhashtable		queue_hash;
+	bool				enable;
+	bool				crc_rx_enable;
+};
+
+void mlx5e_nvmeotcp_build_netdev(struct mlx5e_priv *priv);
+int mlx5e_nvmeotcp_init(struct mlx5e_priv *priv);
+int set_feature_nvme_tcp(struct net_device *netdev, bool enable);
+int set_feature_nvme_tcp_crc(struct net_device *netdev, bool enable);
+void mlx5e_nvmeotcp_cleanup(struct mlx5e_priv *priv);
+int mlx5e_nvmeotcp_init_rx(struct mlx5e_priv *priv);
+void mlx5e_nvmeotcp_cleanup_rx(struct mlx5e_priv *priv);
+#else
+
+static inline void mlx5e_nvmeotcp_build_netdev(struct mlx5e_priv *priv) { }
+static inline int mlx5e_nvmeotcp_init(struct mlx5e_priv *priv) { return 0; }
+static inline void mlx5e_nvmeotcp_cleanup(struct mlx5e_priv *priv) { }
+static inline int set_feature_nvme_tcp(struct net_device *netdev, bool enable) { return 0; }
+static inline int set_feature_nvme_tcp_crc(struct net_device *netdev, bool enable) { return 0; }
+static inline int mlx5e_nvmeotcp_init_rx(struct mlx5e_priv *priv) { return 0; }
+static inline void mlx5e_nvmeotcp_cleanup_rx(struct mlx5e_priv *priv) { }
+#endif
+#endif /* __MLX5E_NVMEOTCP_H__ */
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index 48566e7d49a7..98fe57531ccc 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -47,6 +47,7 @@
 #include "en_accel/ipsec.h"
 #include "en_accel/en_accel.h"
 #include "en_accel/tls.h"
+#include "en_accel/nvmeotcp.h"
 #include "accel/ipsec.h"
 #include "accel/tls.h"
 #include "lib/vxlan.h"
@@ -2010,6 +2011,10 @@ static int mlx5e_open_channel(struct mlx5e_priv *priv, int ix,
 	c->aff_mask = irq_get_effective_affinity_mask(irq);
 	c->lag_port = mlx5e_enumerate_lag_port(priv->mdev, ix);
 
+#ifdef CONFIG_MLX5_EN_NVMEOTCP
+	INIT_LIST_HEAD(&c->list_nvmeotcpsq);
+	spin_lock_init(&c->nvmeotcp_icosq_lock);
+#endif
 	netif_napi_add(netdev, &c->napi, mlx5e_napi_poll, 64);
 
 	err = mlx5e_open_queues(c, params, cparam);
@@ -2246,7 +2251,8 @@ static void mlx5e_build_common_cq_param(struct mlx5e_priv *priv,
 	void *cqc = param->cqc;
 
 	MLX5_SET(cqc, cqc, uar_page, priv->mdev->priv.uar->index);
-	if (MLX5_CAP_GEN(priv->mdev, cqe_128_always) && cache_line_size() >= 128)
+	if (MLX5_CAP_GEN(priv->mdev, cqe_128_always) &&
+	    (cache_line_size() >= 128 || param->force_cqe128))
 		MLX5_SET(cqc, cqc, cqe_sz, CQE_STRIDE_128_PAD);
 }
 
@@ -2260,6 +2266,11 @@ void mlx5e_build_rx_cq_param(struct mlx5e_priv *priv,
 	void *cqc = param->cqc;
 	u8 log_cq_size;
 
+#ifdef CONFIG_MLX5_EN_NVMEOTCP
+	/* nvme-tcp offload mandates 128 byte cqes */
+	param->force_cqe128 |= (priv->nvmeotcp->enable || priv->nvmeotcp->crc_rx_enable);
+#endif
+
 	switch (params->rq_wq_type) {
 	case MLX5_WQ_TYPE_LINKED_LIST_STRIDING_RQ:
 		log_cq_size = mlx5e_mpwqe_get_log_rq_size(params, xsk) +
@@ -3957,6 +3968,10 @@ int mlx5e_set_features(struct net_device *netdev, netdev_features_t features)
 	err |= MLX5E_HANDLE_FEATURE(NETIF_F_NTUPLE, set_feature_arfs);
 #endif
 	err |= MLX5E_HANDLE_FEATURE(NETIF_F_HW_TLS_RX, mlx5e_ktls_set_feature_rx);
+#ifdef CONFIG_MLX5_EN_NVMEOTCP
+	err |= MLX5E_HANDLE_FEATURE(NETIF_F_HW_TCP_DDP, set_feature_nvme_tcp);
+	err |= MLX5E_HANDLE_FEATURE(NETIF_F_HW_TCP_DDP_CRC_RX, set_feature_nvme_tcp_crc);
+#endif
 
 	if (err) {
 		netdev->features = oper_features;
@@ -3993,6 +4008,23 @@ static netdev_features_t mlx5e_fix_features(struct net_device *netdev,
 		features &= ~NETIF_F_RXHASH;
 		if (netdev->features & NETIF_F_RXHASH)
 			netdev_warn(netdev, "Disabling rxhash, not supported when CQE compress is active\n");
+
+		features &= ~NETIF_F_HW_TCP_DDP;
+		if (netdev->features & NETIF_F_HW_TCP_DDP)
+			netdev_warn(netdev, "Disabling tcp-ddp offload, not supported when CQE compress is active\n");
+
+		features &= ~NETIF_F_HW_TCP_DDP_CRC_RX;
+		if (netdev->features & NETIF_F_HW_TCP_DDP_CRC_RX)
+			netdev_warn(netdev, "Disabling tcp-ddp-crc-rx offload, not supported when CQE compression is active\n");
+	}
+
+	if (netdev->features & NETIF_F_LRO) {
+		features &= ~NETIF_F_HW_TCP_DDP;
+		if (netdev->features & NETIF_F_HW_TCP_DDP)
+			netdev_warn(netdev, "Disabling tcp-ddp offload, not supported when LRO is active\n");
+		features &= ~NETIF_F_HW_TCP_DDP_CRC_RX;
+		if (netdev->features & NETIF_F_HW_TCP_DDP_CRC_RX)
+			netdev_warn(netdev, "Disabling tcp-ddp-crc-rx offload, not supported when LRO is active\n");
 	}
 
 	mutex_unlock(&priv->state_lock);
@@ -5064,6 +5096,7 @@ static void mlx5e_build_nic_netdev(struct net_device *netdev)
 	mlx5e_set_netdev_dev_addr(netdev);
 	mlx5e_ipsec_build_netdev(priv);
 	mlx5e_tls_build_netdev(priv);
+	mlx5e_nvmeotcp_build_netdev(priv);
 }
 
 void mlx5e_create_q_counters(struct mlx5e_priv *priv)
@@ -5128,6 +5161,9 @@ static int mlx5e_nic_init(struct mlx5_core_dev *mdev,
 	err = mlx5e_tls_init(priv);
 	if (err)
 		mlx5_core_err(mdev, "TLS initialization failed, %d\n", err);
+	err = mlx5e_nvmeotcp_init(priv);
+	if (err)
+		mlx5_core_err(mdev, "NVMEoTCP initialization failed, %d\n", err);
 	mlx5e_build_nic_netdev(netdev);
 	err = mlx5e_devlink_port_register(priv);
 	if (err)
@@ -5141,6 +5177,7 @@ static void mlx5e_nic_cleanup(struct mlx5e_priv *priv)
 {
 	mlx5e_health_destroy_reporters(priv);
 	mlx5e_devlink_port_unregister(priv);
+	mlx5e_nvmeotcp_cleanup(priv);
 	mlx5e_tls_cleanup(priv);
 	mlx5e_ipsec_cleanup(priv);
 	mlx5e_netdev_cleanup(priv->netdev, priv);
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_txrx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_txrx.c
index a3cfe06d5116..aa0dcebe3a97 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_txrx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_txrx.c
@@ -36,6 +36,7 @@
 #include "en/xdp.h"
 #include "en/xsk/rx.h"
 #include "en/xsk/tx.h"
+#include "en_accel/nvmeotcp.h"
 
 static inline bool mlx5e_channel_no_affinity_change(struct mlx5e_channel *c)
 {
@@ -117,6 +118,10 @@ int mlx5e_napi_poll(struct napi_struct *napi, int budget)
 	struct mlx5e_xdpsq *xsksq = &c->xsksq;
 	struct mlx5e_rq *xskrq = &c->xskrq;
 	struct mlx5e_rq *rq = &c->rq;
+#ifdef CONFIG_MLX5_EN_NVMEOTCP
+	struct mlx5e_nvmeotcp_sq *nvmeotcp_sq;
+	struct list_head *cur;
+#endif
 	bool aff_change = false;
 	bool busy_xsk = false;
 	bool busy = false;
@@ -154,6 +159,12 @@ int mlx5e_napi_poll(struct napi_struct *napi, int budget)
 		 * queueing more WQEs and overflowing the async ICOSQ.
 		 */
 		clear_bit(MLX5E_SQ_STATE_PENDING_XSK_TX, &c->async_icosq.state);
+#ifdef CONFIG_MLX5_EN_NVMEOTCP
+	list_for_each(cur, &c->list_nvmeotcpsq) {
+		nvmeotcp_sq = list_entry(cur, struct mlx5e_nvmeotcp_sq, list);
+		mlx5e_poll_ico_cq(&nvmeotcp_sq->icosq.cq);
+	}
+#endif
 
 	busy |= INDIRECT_CALL_2(rq->post_wqes,
 				mlx5e_post_rx_mpwqes,
@@ -192,6 +203,12 @@ int mlx5e_napi_poll(struct napi_struct *napi, int budget)
 	mlx5e_cq_arm(&rq->cq);
 	mlx5e_cq_arm(&c->icosq.cq);
 	mlx5e_cq_arm(&c->async_icosq.cq);
+#ifdef CONFIG_MLX5_EN_NVMEOTCP
+	list_for_each(cur, &c->list_nvmeotcpsq) {
+		nvmeotcp_sq = list_entry(cur, struct mlx5e_nvmeotcp_sq, list);
+		mlx5e_cq_arm(&nvmeotcp_sq->icosq.cq);
+	}
+#endif
 	mlx5e_cq_arm(&c->xdpsq.cq);
 
 	if (xsk_open) {
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/fw.c b/drivers/net/ethernet/mellanox/mlx5/core/fw.c
index 02558ac2ace6..5e7544ccae91 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/fw.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/fw.c
@@ -256,6 +256,12 @@ int mlx5_query_hca_caps(struct mlx5_core_dev *dev)
 			return err;
 	}
 
+	if (MLX5_CAP_GEN(dev, nvmeotcp)) {
+		err = mlx5_core_get_caps(dev, MLX5_CAP_DEV_NVMEOTCP);
+		if (err)
+			return err;
+	}
+
 	return 0;
 }
 
-- 
2.24.1

[PATCH v2 net-next 14/21] net/mlx5e: KLM UMR helper macros

[Boris Pismenny]

From: Ben Ben-Ishay <benishay@nvidia.com>

Add helper macros for posting KLM UMR WQE.

Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: Ben Ben-Ishay <benishay@nvidia.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Yoray Zack <yorayz@mellanox.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/en.h | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en.h b/drivers/net/ethernet/mellanox/mlx5/core/en.h
index ff100c290b59..26259d68b98a 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en.h
@@ -152,6 +152,24 @@ struct page_pool;
 #define MLX5E_UMR_WQEBBS \
 	(DIV_ROUND_UP(MLX5E_UMR_WQE_INLINE_SZ, MLX5_SEND_WQE_BB))
 
+#define KLM_ALIGNMENT 4
+#define MLX5E_KLM_UMR_WQE_SZ(sgl_len)\
+	(sizeof(struct mlx5e_umr_wqe) +\
+	(sizeof(struct mlx5_klm) * (sgl_len)))
+
+#define MLX5E_KLM_UMR_WQEBBS(sgl_len)\
+	(DIV_ROUND_UP(MLX5E_KLM_UMR_WQE_SZ(sgl_len), MLX5_SEND_WQE_BB))
+
+#define MLX5E_KLM_UMR_DS_CNT(sgl_len)\
+	DIV_ROUND_UP(MLX5E_KLM_UMR_WQE_SZ(sgl_len), MLX5_SEND_WQE_DS)
+
+#define MLX5E_MAX_KLM_ENTRIES_PER_WQE(wqe_size)\
+	(((wqe_size) - sizeof(struct mlx5e_umr_wqe)) / sizeof(struct mlx5_klm))
+
+#define MLX5E_KLM_ENTRIES_PER_WQE(wqe_size)\
+	(MLX5E_MAX_KLM_ENTRIES_PER_WQE(wqe_size) -\
+			(MLX5E_MAX_KLM_ENTRIES_PER_WQE(wqe_size) % KLM_ALIGNMENT))
+
 #define MLX5E_MSG_LEVEL			NETIF_MSG_LINK
 
 #define mlx5e_dbg(mlevel, priv, format, ...)                    \
-- 
2.24.1

[PATCH v2 net-next 15/21] net/mlx5e: NVMEoTCP use KLM UMRs

[Boris Pismenny]

From: Ben Ben-Ishay <benishay@nvidia.com>

NVMEoTCP offload uses buffer registration for ddp operation,
every request comprises from SG list that might have elements with size > 4K,
thus the appropriate way to perform buffer registration is with KLM UMRs.

Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: Ben Ben-Ishay <benishay@nvidia.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Yoray Zack <yorayz@mellanox.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/en.h  |   5 +-
 .../net/ethernet/mellanox/mlx5/core/en/txrx.h |   3 +
 .../mellanox/mlx5/core/en_accel/nvmeotcp.c    | 116 ++++++++++++++++++
 .../mlx5/core/en_accel/nvmeotcp_utils.h       |  12 ++
 .../net/ethernet/mellanox/mlx5/core/en_rx.c   |  12 +-
 5 files changed, 145 insertions(+), 3 deletions(-)
 create mode 100644 drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp_utils.h

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en.h b/drivers/net/ethernet/mellanox/mlx5/core/en.h
index 26259d68b98a..dc6ebcfffb1b 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en.h
@@ -232,7 +232,10 @@ struct mlx5e_umr_wqe {
 	struct mlx5_wqe_ctrl_seg       ctrl;
 	struct mlx5_wqe_umr_ctrl_seg   uctrl;
 	struct mlx5_mkey_seg           mkc;
-	struct mlx5_mtt                inline_mtts[0];
+	union {
+		struct mlx5_mtt        inline_mtts[0];
+		struct mlx5_klm	       inline_klms[0];
+	};
 };
 
 extern const char mlx5e_self_tests[][ETH_GSTRING_LEN];
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/txrx.h b/drivers/net/ethernet/mellanox/mlx5/core/en/txrx.h
index 7943eb30b837..bfeea906612e 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/txrx.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/txrx.h
@@ -34,6 +34,9 @@ enum mlx5e_icosq_wqe_type {
 	MLX5E_ICOSQ_WQE_SET_PSV_TLS,
 	MLX5E_ICOSQ_WQE_GET_PSV_TLS,
 #endif
+#ifdef CONFIG_MLX5_EN_NVMEOTCP
+	MLX5E_ICOSQ_WQE_UMR_NVME_TCP,
+#endif
 };
 
 /* General */
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.c b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.c
index 0834deb7a3ac..bbeded08ef01 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.c
@@ -4,6 +4,7 @@
 #include <linux/netdevice.h>
 #include <linux/idr.h>
 #include "en_accel/nvmeotcp.h"
+#include "en_accel/nvmeotcp_utils.h"
 #include "en_accel/fs_tcp.h"
 #include "en/txrx.h"
 
@@ -19,6 +20,121 @@ static const struct rhashtable_params rhash_queues = {
 	.max_size = MAX_NVMEOTCP_QUEUES,
 };
 
+static void
+fill_nvmeotcp_klm_wqe(struct mlx5e_nvmeotcp_queue *queue,
+		      struct mlx5e_umr_wqe *wqe, u16 ccid, u32 klm_entries,
+		      u16 klm_offset)
+{
+	struct scatterlist *sgl_mkey;
+	u32 lkey, i;
+
+	lkey = queue->priv->mdev->mlx5e_res.mkey.key;
+	for (i = 0; i < klm_entries; i++) {
+		sgl_mkey = &queue->ccid_table[ccid].sgl[i + klm_offset];
+		wqe->inline_klms[i].bcount = cpu_to_be32(sgl_mkey->length);
+		wqe->inline_klms[i].key	   = cpu_to_be32(lkey);
+		wqe->inline_klms[i].va	   = cpu_to_be64(sgl_mkey->dma_address);
+	}
+
+	for (; i < ALIGN(klm_entries, KLM_ALIGNMENT); i++) {
+		wqe->inline_klms[i].bcount = 0;
+		wqe->inline_klms[i].key    = 0;
+		wqe->inline_klms[i].va     = 0;
+	}
+}
+
+static void
+build_nvmeotcp_klm_umr(struct mlx5e_nvmeotcp_queue *queue,
+		       struct mlx5e_umr_wqe *wqe, u16 ccid, int klm_entries,
+		       u32 klm_offset, u32 len)
+{
+	u32 id = queue->ccid_table[ccid].klm_mkey.key;
+	struct mlx5_wqe_umr_ctrl_seg *ucseg = &wqe->uctrl;
+	struct mlx5_wqe_ctrl_seg      *cseg = &wqe->ctrl;
+	struct mlx5_mkey_seg	       *mkc = &wqe->mkc;
+
+	u32 sqn = queue->sq->icosq.sqn;
+	u16 pc = queue->sq->icosq.pc;
+
+	cseg->opmod_idx_opcode = cpu_to_be32((pc << MLX5_WQE_CTRL_WQE_INDEX_SHIFT) |
+					     MLX5_OPCODE_UMR);
+	cseg->qpn_ds = cpu_to_be32((sqn << MLX5_WQE_CTRL_QPN_SHIFT) |
+				   MLX5E_KLM_UMR_DS_CNT(ALIGN(klm_entries, KLM_ALIGNMENT)));
+	cseg->general_id = cpu_to_be32(id);
+
+	if (!klm_offset) {
+		ucseg->mkey_mask |= cpu_to_be64(MLX5_MKEY_MASK_XLT_OCT_SIZE |
+						MLX5_MKEY_MASK_LEN | MLX5_MKEY_MASK_FREE);
+		mkc->xlt_oct_size = cpu_to_be32(ALIGN(len, KLM_ALIGNMENT));
+		mkc->len = cpu_to_be64(queue->ccid_table[ccid].size);
+	}
+
+	ucseg->flags = MLX5_UMR_INLINE | MLX5_UMR_TRANSLATION_OFFSET_EN;
+	ucseg->xlt_octowords = cpu_to_be16(ALIGN(klm_entries, KLM_ALIGNMENT));
+	ucseg->xlt_offset = cpu_to_be16(klm_offset);
+	fill_nvmeotcp_klm_wqe(queue, wqe, ccid, klm_entries, klm_offset);
+}
+
+static void
+mlx5e_nvmeotcp_fill_wi(struct mlx5e_nvmeotcp_queue *nvmeotcp_queue,
+		       struct mlx5e_icosq *sq, u32 wqe_bbs, u16 pi)
+{
+	struct mlx5e_icosq_wqe_info *wi = &sq->db.wqe_info[pi];
+
+	wi->num_wqebbs = wqe_bbs;
+	wi->wqe_type = MLX5E_ICOSQ_WQE_UMR_NVME_TCP;
+}
+
+static void
+post_klm_wqe(struct mlx5e_nvmeotcp_queue *queue,
+	     u16 ccid,
+	     u32 klm_length,
+	     u32 *klm_offset)
+{
+	struct mlx5e_icosq *sq = &queue->sq->icosq;
+	u32 wqe_bbs, cur_klm_entries;
+	struct mlx5e_umr_wqe *wqe;
+	u16 pi, wqe_sz;
+
+	cur_klm_entries = min_t(int, queue->max_klms_per_wqe,
+				klm_length - *klm_offset);
+	wqe_sz = MLX5E_KLM_UMR_WQE_SZ(ALIGN(cur_klm_entries, KLM_ALIGNMENT));
+	wqe_bbs = DIV_ROUND_UP(wqe_sz, MLX5_SEND_WQE_BB);
+	pi = mlx5e_icosq_get_next_pi(sq, wqe_bbs);
+	wqe = MLX5E_NVMEOTCP_FETCH_KLM_WQE(sq, pi);
+	mlx5e_nvmeotcp_fill_wi(queue, sq, wqe_bbs, pi);
+	build_nvmeotcp_klm_umr(queue, wqe, ccid, cur_klm_entries, *klm_offset,
+			       klm_length);
+	*klm_offset += cur_klm_entries;
+	sq->pc += wqe_bbs;
+	sq->doorbell_cseg = &wqe->ctrl;
+}
+
+static int
+mlx5e_nvmeotcp_post_klm_wqe(struct mlx5e_nvmeotcp_queue *queue,
+			    u16 ccid,
+			    u32 klm_length)
+{
+	u32 klm_offset = 0, wqes, wqe_sz, max_wqe_bbs, i, room;
+	struct mlx5e_icosq *sq = &queue->sq->icosq;
+
+	/* TODO: set stricter wqe_sz; using max for now */
+	wqes = DIV_ROUND_UP(klm_length, queue->max_klms_per_wqe);
+	wqe_sz = MLX5E_KLM_UMR_WQE_SZ(queue->max_klms_per_wqe);
+
+	max_wqe_bbs = DIV_ROUND_UP(wqe_sz, MLX5_SEND_WQE_BB);
+
+	room = mlx5e_stop_room_for_wqe(max_wqe_bbs) * wqes;
+	if (unlikely(!mlx5e_wqc_has_room_for(&sq->wq, sq->cc, sq->pc, room)))
+		return -ENOSPC;
+
+	for (i = 0; i < wqes; i++)
+		post_klm_wqe(queue, ccid, klm_length, &klm_offset);
+
+	mlx5e_notify_hw(&sq->wq, sq->pc, sq->uar_map, sq->doorbell_cseg);
+	return 0;
+}
+
 static int
 mlx5e_nvmeotcp_offload_limits(struct net_device *netdev,
 			      struct tcp_ddp_limits *limits)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp_utils.h b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp_utils.h
new file mode 100644
index 000000000000..329e114d6571
--- /dev/null
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp_utils.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
+/* Copyright (c) 2021 Mellanox Technologies. */
+#ifndef __MLX5E_NVMEOTCP_UTILS_H__
+#define __MLX5E_NVMEOTCP_UTILS_H__
+
+#include "en.h"
+
+#define MLX5E_NVMEOTCP_FETCH_KLM_WQE(sq, pi) \
+	((struct mlx5e_umr_wqe *)\
+	 mlx5e_fetch_wqe(&(sq)->wq, pi, sizeof(struct mlx5e_umr_wqe)))
+
+#endif /* __MLX5E_NVMEOTCP_UTILS_H__ */
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
index 377e547840f3..28aa99265c0a 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
@@ -617,16 +617,20 @@ void mlx5e_free_icosq_descs(struct mlx5e_icosq *sq)
 		ci = mlx5_wq_cyc_ctr2ix(&sq->wq, sqcc);
 		wi = &sq->db.wqe_info[ci];
 		sqcc += wi->num_wqebbs;
-#ifdef CONFIG_MLX5_EN_TLS
 		switch (wi->wqe_type) {
+#ifdef CONFIG_MLX5_EN_TLS
 		case MLX5E_ICOSQ_WQE_SET_PSV_TLS:
 			mlx5e_ktls_handle_ctx_completion(wi);
 			break;
 		case MLX5E_ICOSQ_WQE_GET_PSV_TLS:
 			mlx5e_ktls_handle_get_psv_completion(wi, sq);
 			break;
-		}
 #endif
+#ifdef CONFIG_MLX5_EN_NVMEOTCP
+		case MLX5E_ICOSQ_WQE_UMR_NVME_TCP:
+			break;
+#endif
+		}
 	}
 	sq->cc = sqcc;
 }
@@ -695,6 +699,10 @@ int mlx5e_poll_ico_cq(struct mlx5e_cq *cq)
 			case MLX5E_ICOSQ_WQE_GET_PSV_TLS:
 				mlx5e_ktls_handle_get_psv_completion(wi, sq);
 				break;
+#endif
+#ifdef CONFIG_MLX5_EN_NVMEOTCP
+			case MLX5E_ICOSQ_WQE_UMR_NVME_TCP:
+				break;
 #endif
 			default:
 				netdev_WARN_ONCE(cq->netdev,
-- 
2.24.1

[PATCH v2 net-next 16/21] net/mlx5e: NVMEoTCP queue init/teardown

[Boris Pismenny]

From: Ben Ben-Ishay <benishay@nvidia.com>

When nvme-tcp establishes new connections, we allocate a hardware
context to offload operations for this queue:
- Use a separate TIR to identify the queue and maintain the HW context
- Use a separate ICOSQ for maintain the HW context
- Use a separate tag buffer for buffer registration
- Maintain static and progress HW contexts by posting the proper
  WQEs at creation time, or upon resync

Queue teardown will free the corresponding contexts.

Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: Ben Ben-Ishay <benishay@nvidia.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Yoray Zack <yorayz@mellanox.com>
---
 .../net/ethernet/mellanox/mlx5/core/en/txrx.h |   6 +
 .../mellanox/mlx5/core/en_accel/nvmeotcp.c    | 650 +++++++++++++++++-
 .../mellanox/mlx5/core/en_accel/nvmeotcp.h    |   4 +
 .../mlx5/core/en_accel/nvmeotcp_utils.h       |  68 ++
 .../net/ethernet/mellanox/mlx5/core/en_rx.c   |   7 +
 5 files changed, 711 insertions(+), 24 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/txrx.h b/drivers/net/ethernet/mellanox/mlx5/core/en/txrx.h
index bfeea906612e..f00d76f1ded4 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/txrx.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/txrx.h
@@ -36,6 +36,7 @@ enum mlx5e_icosq_wqe_type {
 #endif
 #ifdef CONFIG_MLX5_EN_NVMEOTCP
 	MLX5E_ICOSQ_WQE_UMR_NVME_TCP,
+	MLX5E_ICOSQ_WQE_SET_PSV_NVME_TCP,
 #endif
 };
 
@@ -178,6 +179,11 @@ struct mlx5e_icosq_wqe_info {
 		struct {
 			struct mlx5e_ktls_rx_resync_buf *buf;
 		} tls_get_params;
+#endif
+#ifdef CONFIG_MLX5_EN_NVMEOTCP
+		struct {
+			struct mlx5e_nvmeotcp_queue *queue;
+		} nvmeotcp_q;
 #endif
 	};
 };
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.c b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.c
index bbeded08ef01..3a42477f1bd7 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.c
@@ -3,6 +3,7 @@
 
 #include <linux/netdevice.h>
 #include <linux/idr.h>
+#include <linux/nvme-tcp.h>
 #include "en_accel/nvmeotcp.h"
 #include "en_accel/nvmeotcp_utils.h"
 #include "en_accel/fs_tcp.h"
@@ -20,35 +21,180 @@ static const struct rhashtable_params rhash_queues = {
 	.max_size = MAX_NVMEOTCP_QUEUES,
 };
 
+#define MLX5_NVME_TCP_MAX_SEGMENTS 128
+
+static u32 mlx5e_get_max_sgl(struct mlx5_core_dev *mdev)
+{
+	return min_t(u32,
+		     MLX5_NVME_TCP_MAX_SEGMENTS,
+		     1 << MLX5_CAP_GEN(mdev, log_max_klm_list_size));
+}
+
+static void mlx5e_nvmeotcp_destroy_tir(struct mlx5e_priv *priv, int tirn)
+{
+	mlx5_core_destroy_tir(priv->mdev, tirn);
+}
+
+static inline u32
+mlx5e_get_channel_ix_from_io_cpu(struct mlx5e_priv *priv, u32 io_cpu)
+{
+	int num_channels = priv->channels.params.num_channels;
+	u32 channel_ix = io_cpu;
+
+	if (channel_ix >= num_channels)
+		channel_ix = channel_ix % num_channels;
+
+	return channel_ix;
+}
+
+static int mlx5e_nvmeotcp_create_tir(struct mlx5e_priv *priv,
+				     struct sock *sk,
+				     struct nvme_tcp_ddp_config *config,
+				     struct mlx5e_nvmeotcp_queue *queue,
+				     bool zerocopy, bool crc_rx)
+{
+	u32 rqtn = priv->direct_tir[queue->channel_ix].rqt.rqtn;
+	int err, inlen;
+	void *tirc;
+	u32 tirn;
+	u32 *in;
+
+	inlen = MLX5_ST_SZ_BYTES(create_tir_in);
+	in = kvzalloc(inlen, GFP_KERNEL);
+	if (!in)
+		return -ENOMEM;
+	tirc = MLX5_ADDR_OF(create_tir_in, in, ctx);
+	MLX5_SET(tirc, tirc, disp_type, MLX5_TIRC_DISP_TYPE_INDIRECT);
+	MLX5_SET(tirc, tirc, rx_hash_fn, MLX5_RX_HASH_FN_INVERTED_XOR8);
+	MLX5_SET(tirc, tirc, indirect_table, rqtn);
+	MLX5_SET(tirc, tirc, transport_domain, priv->mdev->mlx5e_res.td.tdn);
+	if (zerocopy) {
+		MLX5_SET(tirc, tirc, nvmeotcp_zero_copy_en, 1);
+		MLX5_SET(tirc, tirc, nvmeotcp_tag_buffer_table_id,
+			 queue->tag_buf_table_id);
+	}
+
+	if (crc_rx)
+		MLX5_SET(tirc, tirc, nvmeotcp_crc_en, 1);
+
+	MLX5_SET(tirc, tirc, self_lb_block,
+		 MLX5_TIRC_SELF_LB_BLOCK_BLOCK_UNICAST |
+		 MLX5_TIRC_SELF_LB_BLOCK_BLOCK_MULTICAST);
+	err = mlx5_core_create_tir(priv->mdev, in, &tirn);
+
+	if (!err)
+		queue->tirn = tirn;
+
+	kvfree(in);
+	return err;
+}
+
+static
+int mlx5e_create_nvmeotcp_tag_buf_table(struct mlx5_core_dev *mdev,
+					struct mlx5e_nvmeotcp_queue *queue,
+					u8 log_table_size)
+{
+	u32 in[MLX5_ST_SZ_DW(create_nvmeotcp_tag_buf_table_in)] = {};
+	u32 out[MLX5_ST_SZ_DW(general_obj_out_cmd_hdr)];
+	u64 general_obj_types;
+	void *obj;
+	int err;
+
+	obj = MLX5_ADDR_OF(create_nvmeotcp_tag_buf_table_in, in,
+			   nvmeotcp_tag_buf_table_obj);
+
+	general_obj_types = MLX5_CAP_GEN_64(mdev, general_obj_types);
+	if (!(general_obj_types &
+	      MLX5_HCA_CAP_GENERAL_OBJECT_TYPES_NVMEOTCP_TAG_BUFFER_TABLE))
+		return -EINVAL;
+
+	MLX5_SET(general_obj_in_cmd_hdr, in, opcode,
+		 MLX5_CMD_OP_CREATE_GENERAL_OBJECT);
+	MLX5_SET(general_obj_in_cmd_hdr, in, obj_type,
+		 MLX5_GENERAL_OBJECT_TYPES_NVMEOTCP_TAG_BUFFER_TABLE);
+	MLX5_SET(nvmeotcp_tag_buf_table_obj, obj,
+		 log_tag_buffer_table_size, log_table_size);
+
+	err = mlx5_cmd_exec(mdev, in, sizeof(in), out, sizeof(out));
+	if (!err)
+		queue->tag_buf_table_id = MLX5_GET(general_obj_out_cmd_hdr,
+						   out, obj_id);
+	return err;
+}
+
+static
+void mlx5_destroy_nvmeotcp_tag_buf_table(struct mlx5_core_dev *mdev, u32 uid)
+{
+	u32 in[MLX5_ST_SZ_DW(general_obj_in_cmd_hdr)] = {};
+	u32 out[MLX5_ST_SZ_DW(general_obj_out_cmd_hdr)];
+
+	MLX5_SET(general_obj_in_cmd_hdr, in, opcode,
+		 MLX5_CMD_OP_DESTROY_GENERAL_OBJECT);
+	MLX5_SET(general_obj_in_cmd_hdr, in, obj_type,
+		 MLX5_GENERAL_OBJECT_TYPES_NVMEOTCP_TAG_BUFFER_TABLE);
+	MLX5_SET(general_obj_in_cmd_hdr, in, obj_id, uid);
+
+	mlx5_cmd_exec(mdev, in, sizeof(in), out, sizeof(out));
+}
+
+#define MLX5_CTRL_SEGMENT_OPC_MOD_UMR_TIR_PARAMS 0x2
+#define MLX5_CTRL_SEGMENT_OPC_MOD_UMR_NVMEOTCP_TIR_STATIC_PARAMS 0x2
+#define MLX5_CTRL_SEGMENT_OPC_MOD_UMR_UMR 0x0
+
+#define STATIC_PARAMS_DS_CNT \
+	DIV_ROUND_UP(MLX5E_NVMEOTCP_STATIC_PARAMS_WQE_SZ, MLX5_SEND_WQE_DS)
+
+#define PROGRESS_PARAMS_DS_CNT \
+	DIV_ROUND_UP(MLX5E_NVMEOTCP_PROGRESS_PARAMS_WQE_SZ, MLX5_SEND_WQE_DS)
+
+enum wqe_type {
+	KLM_UMR = 0,
+	BSF_KLM_UMR = 1,
+	SET_PSV_UMR = 2,
+	BSF_UMR = 3,
+};
+
 static void
 fill_nvmeotcp_klm_wqe(struct mlx5e_nvmeotcp_queue *queue,
 		      struct mlx5e_umr_wqe *wqe, u16 ccid, u32 klm_entries,
-		      u16 klm_offset)
+		      u16 klm_offset, enum wqe_type klm_type)
 {
 	struct scatterlist *sgl_mkey;
 	u32 lkey, i;
 
-	lkey = queue->priv->mdev->mlx5e_res.mkey.key;
-	for (i = 0; i < klm_entries; i++) {
-		sgl_mkey = &queue->ccid_table[ccid].sgl[i + klm_offset];
-		wqe->inline_klms[i].bcount = cpu_to_be32(sgl_mkey->length);
-		wqe->inline_klms[i].key	   = cpu_to_be32(lkey);
-		wqe->inline_klms[i].va	   = cpu_to_be64(sgl_mkey->dma_address);
-	}
-
-	for (; i < ALIGN(klm_entries, KLM_ALIGNMENT); i++) {
-		wqe->inline_klms[i].bcount = 0;
-		wqe->inline_klms[i].key    = 0;
-		wqe->inline_klms[i].va     = 0;
+	if (klm_type == BSF_KLM_UMR) {
+		for (i = 0; i < klm_entries; i++) {
+			lkey = queue->ccid_table[i + klm_offset].klm_mkey.key;
+			wqe->inline_klms[i].bcount = cpu_to_be32(1);
+			wqe->inline_klms[i].key	   = cpu_to_be32(lkey);
+			wqe->inline_klms[i].va	   = 0;
+		}
+	} else {
+		lkey = queue->priv->mdev->mlx5e_res.mkey.key;
+		for (i = 0; i < klm_entries; i++) {
+			sgl_mkey = &queue->ccid_table[ccid].sgl[i + klm_offset];
+			wqe->inline_klms[i].bcount = cpu_to_be32(sgl_mkey->length);
+			wqe->inline_klms[i].key	   = cpu_to_be32(lkey);
+			wqe->inline_klms[i].va	   = cpu_to_be64(sgl_mkey->dma_address);
+		}
+
+		for (; i < ALIGN(klm_entries, KLM_ALIGNMENT); i++) {
+			wqe->inline_klms[i].bcount = 0;
+			wqe->inline_klms[i].key    = 0;
+			wqe->inline_klms[i].va     = 0;
+		}
 	}
 }
 
 static void
 build_nvmeotcp_klm_umr(struct mlx5e_nvmeotcp_queue *queue,
 		       struct mlx5e_umr_wqe *wqe, u16 ccid, int klm_entries,
-		       u32 klm_offset, u32 len)
+		       u32 klm_offset, u32 len, enum wqe_type klm_type)
 {
-	u32 id = queue->ccid_table[ccid].klm_mkey.key;
+	u32 id = (klm_type == KLM_UMR) ? queue->ccid_table[ccid].klm_mkey.key :
+		(queue->tirn << MLX5_WQE_CTRL_TIR_TIS_INDEX_SHIFT);
+	u8 opc_mod = (klm_type == KLM_UMR) ? MLX5_CTRL_SEGMENT_OPC_MOD_UMR_UMR :
+		MLX5_CTRL_SEGMENT_OPC_MOD_UMR_NVMEOTCP_TIR_STATIC_PARAMS;
 	struct mlx5_wqe_umr_ctrl_seg *ucseg = &wqe->uctrl;
 	struct mlx5_wqe_ctrl_seg      *cseg = &wqe->ctrl;
 	struct mlx5_mkey_seg	       *mkc = &wqe->mkc;
@@ -57,12 +203,12 @@ build_nvmeotcp_klm_umr(struct mlx5e_nvmeotcp_queue *queue,
 	u16 pc = queue->sq->icosq.pc;
 
 	cseg->opmod_idx_opcode = cpu_to_be32((pc << MLX5_WQE_CTRL_WQE_INDEX_SHIFT) |
-					     MLX5_OPCODE_UMR);
+					     MLX5_OPCODE_UMR | (opc_mod) << 24);
 	cseg->qpn_ds = cpu_to_be32((sqn << MLX5_WQE_CTRL_QPN_SHIFT) |
 				   MLX5E_KLM_UMR_DS_CNT(ALIGN(klm_entries, KLM_ALIGNMENT)));
 	cseg->general_id = cpu_to_be32(id);
 
-	if (!klm_offset) {
+	if (klm_type == KLM_UMR && !klm_offset) {
 		ucseg->mkey_mask |= cpu_to_be64(MLX5_MKEY_MASK_XLT_OCT_SIZE |
 						MLX5_MKEY_MASK_LEN | MLX5_MKEY_MASK_FREE);
 		mkc->xlt_oct_size = cpu_to_be32(ALIGN(len, KLM_ALIGNMENT));
@@ -72,21 +218,150 @@ build_nvmeotcp_klm_umr(struct mlx5e_nvmeotcp_queue *queue,
 	ucseg->flags = MLX5_UMR_INLINE | MLX5_UMR_TRANSLATION_OFFSET_EN;
 	ucseg->xlt_octowords = cpu_to_be16(ALIGN(klm_entries, KLM_ALIGNMENT));
 	ucseg->xlt_offset = cpu_to_be16(klm_offset);
-	fill_nvmeotcp_klm_wqe(queue, wqe, ccid, klm_entries, klm_offset);
+	fill_nvmeotcp_klm_wqe(queue, wqe, ccid, klm_entries, klm_offset, klm_type);
+}
+
+static void
+fill_nvmeotcp_progress_params(struct mlx5e_nvmeotcp_queue *queue,
+			      struct mlx5_seg_nvmeotcp_progress_params *params,
+			      u32 seq)
+{
+	void *ctx = params->ctx;
+
+	params->tir_num = cpu_to_be32(queue->tirn);
+
+	MLX5_SET(nvmeotcp_progress_params, ctx,
+		 next_pdu_tcp_sn, seq);
+	MLX5_SET(nvmeotcp_progress_params, ctx, pdu_tracker_state,
+		 MLX5E_NVMEOTCP_PROGRESS_PARAMS_PDU_TRACKER_STATE_START);
+}
+
+void
+build_nvmeotcp_progress_params(struct mlx5e_nvmeotcp_queue *queue,
+			       struct mlx5e_set_nvmeotcp_progress_params_wqe *wqe,
+			       u32 seq)
+{
+	struct mlx5_wqe_ctrl_seg *cseg = &wqe->ctrl;
+	u32 sqn = queue->sq->icosq.sqn;
+	u16 pc = queue->sq->icosq.pc;
+	u8 opc_mod;
+
+	memset(wqe, 0, MLX5E_NVMEOTCP_PROGRESS_PARAMS_WQE_SZ);
+	opc_mod = MLX5_CTRL_SEGMENT_OPC_MOD_UMR_NVMEOTCP_TIR_PROGRESS_PARAMS;
+	cseg->opmod_idx_opcode = cpu_to_be32((pc << MLX5_WQE_CTRL_WQE_INDEX_SHIFT) |
+					     MLX5_OPCODE_SET_PSV | (opc_mod << 24));
+	cseg->qpn_ds = cpu_to_be32((sqn << MLX5_WQE_CTRL_QPN_SHIFT) |
+				   PROGRESS_PARAMS_DS_CNT);
+	fill_nvmeotcp_progress_params(queue, &wqe->params, seq);
+}
+
+static void
+fill_nvmeotcp_static_params(struct mlx5e_nvmeotcp_queue *queue,
+			    struct mlx5_seg_nvmeotcp_static_params *params,
+			    u32 resync_seq, bool zero_copy_en,
+			    bool ddgst_offload_en)
+{
+	void *ctx = params->ctx;
+
+	MLX5_SET(transport_static_params, ctx, const_1, 1);
+	MLX5_SET(transport_static_params, ctx, const_2, 2);
+	MLX5_SET(transport_static_params, ctx, acc_type,
+		 MLX5_TRANSPORT_STATIC_PARAMS_ACC_TYPE_NVMETCP);
+	MLX5_SET(transport_static_params, ctx, nvme_resync_tcp_sn, resync_seq);
+	MLX5_SET(transport_static_params, ctx, pda, queue->pda);
+	MLX5_SET(transport_static_params, ctx, ddgst_en, queue->dgst);
+	MLX5_SET(transport_static_params, ctx, ddgst_offload_en, ddgst_offload_en);
+	MLX5_SET(transport_static_params, ctx, hddgst_en, 0);
+	MLX5_SET(transport_static_params, ctx, hdgst_offload_en, 0);
+	MLX5_SET(transport_static_params, ctx, ti,
+		 MLX5_TRANSPORT_STATIC_PARAMS_TI_INITIATOR);
+	MLX5_SET(transport_static_params, ctx, const1, 1);
+	MLX5_SET(transport_static_params, ctx, zero_copy_en, zero_copy_en);
+}
+
+void
+build_nvmeotcp_static_params(struct mlx5e_nvmeotcp_queue *queue,
+			     struct mlx5e_set_nvmeotcp_static_params_wqe *wqe,
+			     u32 resync_seq, bool zerocopy, bool crc_rx)
+{
+	u8 opc_mod = MLX5_CTRL_SEGMENT_OPC_MOD_UMR_NVMEOTCP_TIR_STATIC_PARAMS;
+	struct mlx5_wqe_umr_ctrl_seg *ucseg = &wqe->uctrl;
+	struct mlx5_wqe_ctrl_seg      *cseg = &wqe->ctrl;
+	u32 sqn = queue->sq->icosq.sqn;
+	u16 pc = queue->sq->icosq.pc;
+
+	memset(wqe, 0, MLX5E_NVMEOTCP_STATIC_PARAMS_WQE_SZ);
+
+	cseg->opmod_idx_opcode = cpu_to_be32((pc << MLX5_WQE_CTRL_WQE_INDEX_SHIFT) |
+					     MLX5_OPCODE_UMR | (opc_mod) << 24);
+	cseg->qpn_ds = cpu_to_be32((sqn << MLX5_WQE_CTRL_QPN_SHIFT) |
+				   STATIC_PARAMS_DS_CNT);
+	cseg->imm = cpu_to_be32(queue->tirn << MLX5_WQE_CTRL_TIR_TIS_INDEX_SHIFT);
+
+	ucseg->flags = MLX5_UMR_INLINE;
+	ucseg->bsf_octowords =
+		cpu_to_be16(MLX5E_NVMEOTCP_STATIC_PARAMS_OCTWORD_SIZE);
+	fill_nvmeotcp_static_params(queue, &wqe->params, resync_seq, zerocopy, crc_rx);
 }
 
 static void
 mlx5e_nvmeotcp_fill_wi(struct mlx5e_nvmeotcp_queue *nvmeotcp_queue,
-		       struct mlx5e_icosq *sq, u32 wqe_bbs, u16 pi)
+		       struct mlx5e_icosq *sq, u32 wqe_bbs, u16 pi,
+		       enum wqe_type type)
 {
 	struct mlx5e_icosq_wqe_info *wi = &sq->db.wqe_info[pi];
 
 	wi->num_wqebbs = wqe_bbs;
-	wi->wqe_type = MLX5E_ICOSQ_WQE_UMR_NVME_TCP;
+	switch (type) {
+	case SET_PSV_UMR:
+		wi->wqe_type = MLX5E_ICOSQ_WQE_SET_PSV_NVME_TCP;
+		break;
+	default:
+		wi->wqe_type = MLX5E_ICOSQ_WQE_UMR_NVME_TCP;
+		break;
+	}
+
+	if (type == SET_PSV_UMR)
+		wi->nvmeotcp_q.queue = nvmeotcp_queue;
+}
+
+static void
+mlx5e_nvmeotcp_rx_post_static_params_wqe(struct mlx5e_nvmeotcp_queue *queue,
+					 u32 resync_seq)
+{
+	struct mlx5e_set_nvmeotcp_static_params_wqe *wqe;
+	struct mlx5e_icosq *sq = &queue->sq->icosq;
+	u16 pi, wqe_bbs;
+
+	wqe_bbs = MLX5E_NVMEOTCP_STATIC_PARAMS_WQEBBS;
+	pi = mlx5e_icosq_get_next_pi(sq, wqe_bbs);
+	wqe = MLX5E_NVMEOTCP_FETCH_STATIC_PARAMS_WQE(sq, pi);
+	mlx5e_nvmeotcp_fill_wi(NULL, sq, wqe_bbs, pi, BSF_UMR);
+	build_nvmeotcp_static_params(queue, wqe, resync_seq, queue->zerocopy, queue->crc_rx);
+	sq->pc += wqe_bbs;
+	mlx5e_notify_hw(&sq->wq, sq->pc, sq->uar_map, &wqe->ctrl);
+}
+
+static void
+mlx5e_nvmeotcp_rx_post_progress_params_wqe(struct mlx5e_nvmeotcp_queue *queue,
+					   u32 seq)
+{
+	struct mlx5e_set_nvmeotcp_progress_params_wqe *wqe;
+	struct mlx5e_icosq *sq = &queue->sq->icosq;
+	u16 pi, wqe_bbs;
+
+	wqe_bbs = MLX5E_NVMEOTCP_PROGRESS_PARAMS_WQEBBS;
+	pi = mlx5e_icosq_get_next_pi(sq, wqe_bbs);
+	wqe = MLX5E_NVMEOTCP_FETCH_PROGRESS_PARAMS_WQE(sq, pi);
+	mlx5e_nvmeotcp_fill_wi(queue, sq, wqe_bbs, pi, SET_PSV_UMR);
+	build_nvmeotcp_progress_params(queue, wqe, seq);
+	sq->pc += wqe_bbs;
+	mlx5e_notify_hw(&sq->wq, sq->pc, sq->uar_map, &wqe->ctrl);
 }
 
 static void
 post_klm_wqe(struct mlx5e_nvmeotcp_queue *queue,
+	     enum wqe_type wqe_type,
 	     u16 ccid,
 	     u32 klm_length,
 	     u32 *klm_offset)
@@ -102,9 +377,9 @@ post_klm_wqe(struct mlx5e_nvmeotcp_queue *queue,
 	wqe_bbs = DIV_ROUND_UP(wqe_sz, MLX5_SEND_WQE_BB);
 	pi = mlx5e_icosq_get_next_pi(sq, wqe_bbs);
 	wqe = MLX5E_NVMEOTCP_FETCH_KLM_WQE(sq, pi);
-	mlx5e_nvmeotcp_fill_wi(queue, sq, wqe_bbs, pi);
+	mlx5e_nvmeotcp_fill_wi(queue, sq, wqe_bbs, pi, wqe_type);
 	build_nvmeotcp_klm_umr(queue, wqe, ccid, cur_klm_entries, *klm_offset,
-			       klm_length);
+			       klm_length, wqe_type);
 	*klm_offset += cur_klm_entries;
 	sq->pc += wqe_bbs;
 	sq->doorbell_cseg = &wqe->ctrl;
@@ -112,6 +387,7 @@ post_klm_wqe(struct mlx5e_nvmeotcp_queue *queue,
 
 static int
 mlx5e_nvmeotcp_post_klm_wqe(struct mlx5e_nvmeotcp_queue *queue,
+			    enum wqe_type wqe_type,
 			    u16 ccid,
 			    u32 klm_length)
 {
@@ -129,31 +405,326 @@ mlx5e_nvmeotcp_post_klm_wqe(struct mlx5e_nvmeotcp_queue *queue,
 		return -ENOSPC;
 
 	for (i = 0; i < wqes; i++)
-		post_klm_wqe(queue, ccid, klm_length, &klm_offset);
+		post_klm_wqe(queue, wqe_type, ccid, klm_length, &klm_offset);
 
 	mlx5e_notify_hw(&sq->wq, sq->pc, sq->uar_map, sq->doorbell_cseg);
 	return 0;
 }
 
+static int mlx5e_create_nvmeotcp_mkey(struct mlx5_core_dev *mdev,
+				      u8 access_mode,
+				      u32 translation_octword_size,
+				      struct mlx5_core_mkey *mkey)
+{
+	int inlen = MLX5_ST_SZ_BYTES(create_mkey_in);
+	void *mkc;
+	u32 *in;
+	int err;
+
+	in = kvzalloc(inlen, GFP_KERNEL);
+	if (!in)
+		return -ENOMEM;
+
+	mkc = MLX5_ADDR_OF(create_mkey_in, in, memory_key_mkey_entry);
+	MLX5_SET(mkc, mkc, free, 1);
+	MLX5_SET(mkc, mkc, translations_octword_size, translation_octword_size);
+	MLX5_SET(mkc, mkc, umr_en, 1);
+	MLX5_SET(mkc, mkc, lw, 1);
+	MLX5_SET(mkc, mkc, lr, 1);
+	MLX5_SET(mkc, mkc, access_mode_1_0, access_mode);
+
+	MLX5_SET(mkc, mkc, qpn, 0xffffff);
+	MLX5_SET(mkc, mkc, pd, mdev->mlx5e_res.pdn);
+
+	err = mlx5_core_create_mkey(mdev, mkey, in, inlen);
+
+	kvfree(in);
+	return err;
+}
+
 static int
 mlx5e_nvmeotcp_offload_limits(struct net_device *netdev,
 			      struct tcp_ddp_limits *limits)
 {
+	struct mlx5e_priv *priv = netdev_priv(netdev);
+	struct mlx5_core_dev *mdev = priv->mdev;
+
+	limits->max_ddp_sgl_len = mlx5e_get_max_sgl(mdev);
+	return 0;
+}
+
+static void
+mlx5e_nvmeotcp_destroy_sq(struct mlx5e_nvmeotcp_sq *nvmeotcpsq)
+{
+	mlx5e_deactivate_icosq(&nvmeotcpsq->icosq);
+	mlx5e_close_icosq(&nvmeotcpsq->icosq);
+	mlx5e_close_cq(&nvmeotcpsq->icosq.cq);
+	list_del(&nvmeotcpsq->list);
+	kfree(nvmeotcpsq);
+}
+
+static int
+mlx5e_nvmeotcp_build_icosq(struct mlx5e_nvmeotcp_queue *queue,
+			   struct mlx5e_priv *priv)
+{
+	u16 max_sgl, max_klm_per_wqe, max_umr_per_ccid, sgl_rest, wqebbs_rest;
+	struct mlx5e_channel *c = priv->channels.c[queue->channel_ix];
+	struct mlx5e_sq_param icosq_param = {0};
+	struct dim_cq_moder icocq_moder = {0};
+	struct mlx5e_nvmeotcp_sq *nvmeotcp_sq;
+	struct mlx5e_create_cq_param ccp;
+	struct mlx5e_icosq *icosq;
+	int err = -ENOMEM;
+	u16 log_icosq_sz;
+	u32 max_wqebbs;
+
+	nvmeotcp_sq = kzalloc(sizeof(*nvmeotcp_sq), GFP_KERNEL);
+	if (!nvmeotcp_sq)
+		return err;
+
+	icosq = &nvmeotcp_sq->icosq;
+	max_sgl = mlx5e_get_max_sgl(priv->mdev);
+	max_klm_per_wqe = queue->max_klms_per_wqe;
+	max_umr_per_ccid = max_sgl / max_klm_per_wqe;
+	sgl_rest = max_sgl % max_klm_per_wqe;
+	wqebbs_rest = sgl_rest ? MLX5E_KLM_UMR_WQEBBS(sgl_rest) : 0;
+	max_wqebbs = (MLX5E_KLM_UMR_WQEBBS(max_klm_per_wqe) *
+		     max_umr_per_ccid + wqebbs_rest) * queue->size;
+	log_icosq_sz = order_base_2(max_wqebbs);
+
+	mlx5e_build_icosq_param(priv, log_icosq_sz, &icosq_param);
+	mlx5e_build_create_cq_param(&ccp, c);
+	err = mlx5e_open_cq(priv, icocq_moder, &icosq_param.cqp, &ccp, &icosq->cq);
+	if (err)
+		goto err_nvmeotcp_sq;
+
+	err = mlx5e_open_icosq(c, &priv->channels.params, &icosq_param, icosq);
+	if (err)
+		goto close_cq;
+
+	INIT_LIST_HEAD(&nvmeotcp_sq->list);
+	spin_lock(&c->nvmeotcp_icosq_lock);
+	list_add(&nvmeotcp_sq->list, &c->list_nvmeotcpsq);
+	spin_unlock(&c->nvmeotcp_icosq_lock);
+	queue->sq = nvmeotcp_sq;
+	mlx5e_activate_icosq(icosq);
+	return 0;
+
+close_cq:
+	mlx5e_close_cq(&icosq->cq);
+err_nvmeotcp_sq:
+	kfree(nvmeotcp_sq);
+
+	return err;
+}
+
+static void
+mlx5e_nvmeotcp_destroy_rx(struct mlx5e_nvmeotcp_queue *queue,
+			  struct mlx5_core_dev *mdev, bool zerocopy)
+{
+	int i;
+
+	mlx5e_accel_fs_del_sk(queue->fh);
+	for (i = 0; i < queue->size && zerocopy; i++)
+		mlx5_core_destroy_mkey(mdev, &queue->ccid_table[i].klm_mkey);
+
+	mlx5e_nvmeotcp_destroy_tir(queue->priv, queue->tirn);
+	if (zerocopy) {
+		kfree(queue->ccid_table);
+		mlx5_destroy_nvmeotcp_tag_buf_table(mdev, queue->tag_buf_table_id);
+	}
+
+	mlx5e_nvmeotcp_destroy_sq(queue->sq);
+}
+
+static int
+mlx5e_nvmeotcp_queue_rx_init(struct mlx5e_nvmeotcp_queue *queue,
+			     struct nvme_tcp_ddp_config *config,
+			     struct net_device *netdev,
+			     bool zerocopy, bool crc)
+{
+	u8 log_queue_size = order_base_2(config->queue_size);
+	struct mlx5e_priv *priv = netdev_priv(netdev);
+	struct mlx5_core_dev *mdev = priv->mdev;
+	struct sock *sk = queue->sk;
+	int err, max_sgls, i;
+
+	if (zerocopy) {
+		if (config->queue_size >
+		    BIT(MLX5_CAP_DEV_NVMEOTCP(mdev, log_max_nvmeotcp_tag_buffer_size))) {
+			return -EINVAL;
+		}
+
+		err = mlx5e_create_nvmeotcp_tag_buf_table(mdev, queue, log_queue_size);
+		if (err)
+			return err;
+	}
+
+	err = mlx5e_nvmeotcp_build_icosq(queue, priv);
+	if (err)
+		goto destroy_tag_buffer_table;
+
+	/* initializes queue->tirn */
+	err = mlx5e_nvmeotcp_create_tir(priv, sk, config, queue, zerocopy, crc);
+	if (err)
+		goto destroy_icosq;
+
+	mlx5e_nvmeotcp_rx_post_static_params_wqe(queue, 0);
+	mlx5e_nvmeotcp_rx_post_progress_params_wqe(queue, tcp_sk(sk)->copied_seq);
+
+	if (zerocopy) {
+		queue->ccid_table = kcalloc(queue->size,
+					    sizeof(struct nvmeotcp_queue_entry),
+					    GFP_KERNEL);
+		if (!queue->ccid_table) {
+			err = -ENOMEM;
+			goto destroy_tir;
+		}
+
+		max_sgls = mlx5e_get_max_sgl(mdev);
+		for (i = 0; i < queue->size; i++) {
+			err = mlx5e_create_nvmeotcp_mkey(mdev,
+							 MLX5_MKC_ACCESS_MODE_KLMS,
+							 max_sgls,
+							 &queue->ccid_table[i].klm_mkey);
+			if (err)
+				goto free_sgl;
+		}
+
+		err = mlx5e_nvmeotcp_post_klm_wqe(queue, BSF_KLM_UMR, 0, queue->size);
+		if (err)
+			goto free_sgl;
+	}
+
+	if (!(WARN_ON(!wait_for_completion_timeout(&queue->done, 0))))
+		queue->fh = mlx5e_accel_fs_add_sk(priv, sk, queue->tirn, queue->id);
+
+	if (IS_ERR_OR_NULL(queue->fh)) {
+		err = -EINVAL;
+		goto free_sgl;
+	}
+
 	return 0;
+
+free_sgl:
+	while ((i--) && zerocopy)
+		mlx5_core_destroy_mkey(mdev, &queue->ccid_table[i].klm_mkey);
+
+	if (zerocopy)
+		kfree(queue->ccid_table);
+destroy_tir:
+	mlx5e_nvmeotcp_destroy_tir(priv, queue->tirn);
+destroy_icosq:
+	mlx5e_nvmeotcp_destroy_sq(queue->sq);
+destroy_tag_buffer_table:
+	if (zerocopy)
+		mlx5_destroy_nvmeotcp_tag_buf_table(mdev, queue->tag_buf_table_id);
+
+	return err;
 }
 
+#define OCTWORD_SHIFT 4
+#define MAX_DS_VALUE 63
 static int
 mlx5e_nvmeotcp_queue_init(struct net_device *netdev,
 			  struct sock *sk,
 			  struct tcp_ddp_config *tconfig)
 {
-	return 0;
+	struct nvme_tcp_ddp_config *config = (struct nvme_tcp_ddp_config *)tconfig;
+	bool crc_rx = (netdev->features & NETIF_F_HW_TCP_DDP_CRC_RX);
+	bool zerocopy = (netdev->features & NETIF_F_HW_TCP_DDP);
+	struct mlx5e_priv *priv = netdev_priv(netdev);
+	struct mlx5_core_dev *mdev = priv->mdev;
+	struct mlx5e_nvmeotcp_queue *queue;
+	int max_wqe_sz_cap, queue_id, err;
+
+	if (tconfig->type != TCP_DDP_NVME) {
+		err = -EOPNOTSUPP;
+		goto out;
+	}
+
+	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
+	if (!queue) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	queue_id = ida_simple_get(&priv->nvmeotcp->queue_ids,
+				  MIN_NVMEOTCP_QUEUES, MAX_NVMEOTCP_QUEUES,
+				  GFP_KERNEL);
+	if (queue_id < 0) {
+		err = -ENOSPC;
+		goto free_queue;
+	}
+
+	queue->crc_rx = crc_rx;
+	queue->zerocopy = zerocopy;
+	queue->tcp_ddp_ctx.type = TCP_DDP_NVME;
+	queue->sk = sk;
+	queue->id = queue_id;
+	queue->dgst = config->dgst;
+	queue->pda = config->cpda;
+	queue->channel_ix = mlx5e_get_channel_ix_from_io_cpu(priv,
+							     config->io_cpu);
+	queue->size = config->queue_size;
+	max_wqe_sz_cap  = min_t(int, MAX_DS_VALUE * MLX5_SEND_WQE_DS,
+				MLX5_CAP_GEN(mdev, max_wqe_sz_sq) << OCTWORD_SHIFT);
+	queue->max_klms_per_wqe = MLX5E_KLM_ENTRIES_PER_WQE(max_wqe_sz_cap);
+	queue->priv = priv;
+	init_completion(&queue->done);
+
+	if (zerocopy || crc_rx) {
+		err = mlx5e_nvmeotcp_queue_rx_init(queue, config, netdev,
+						   zerocopy, crc_rx);
+		if (err)
+			goto remove_queue_id;
+	}
+
+	err = rhashtable_insert_fast(&priv->nvmeotcp->queue_hash, &queue->hash,
+				     rhash_queues);
+	if (err)
+		goto destroy_rx;
+
+	write_lock_bh(&sk->sk_callback_lock);
+	tcp_ddp_set_ctx(sk, queue);
+	write_unlock_bh(&sk->sk_callback_lock);
+	refcount_set(&queue->ref_count, 1);
+	return err;
+
+destroy_rx:
+	if (zerocopy || crc_rx)
+		mlx5e_nvmeotcp_destroy_rx(queue, mdev, zerocopy);
+remove_queue_id:
+	ida_simple_remove(&priv->nvmeotcp->queue_ids, queue_id);
+free_queue:
+	kfree(queue);
+out:
+	return err;
 }
 
 static void
 mlx5e_nvmeotcp_queue_teardown(struct net_device *netdev,
 			      struct sock *sk)
 {
+	struct mlx5e_priv *priv = netdev_priv(netdev);
+	struct mlx5_core_dev *mdev = priv->mdev;
+	struct mlx5e_nvmeotcp_queue *queue;
+
+	queue = container_of(tcp_ddp_get_ctx(sk), struct mlx5e_nvmeotcp_queue, tcp_ddp_ctx);
+
+	napi_synchronize(&priv->channels.c[queue->channel_ix]->napi);
+
+	WARN_ON(refcount_read(&queue->ref_count) != 1);
+	if (queue->zerocopy | queue->crc_rx)
+		mlx5e_nvmeotcp_destroy_rx(queue, mdev, queue->zerocopy);
+
+	rhashtable_remove_fast(&priv->nvmeotcp->queue_hash, &queue->hash,
+			       rhash_queues);
+	ida_simple_remove(&priv->nvmeotcp->queue_ids, queue->id);
+	write_lock_bh(&sk->sk_callback_lock);
+	tcp_ddp_set_ctx(sk, NULL);
+	write_unlock_bh(&sk->sk_callback_lock);
+	mlx5e_nvmeotcp_put_queue(queue);
 }
 
 static int
@@ -164,6 +735,16 @@ mlx5e_nvmeotcp_ddp_setup(struct net_device *netdev,
 	return 0;
 }
 
+void mlx5e_nvmeotcp_ctx_comp(struct mlx5e_icosq_wqe_info *wi)
+{
+	struct mlx5e_nvmeotcp_queue *queue = wi->nvmeotcp_q.queue;
+
+	if (unlikely(!queue))
+		return;
+
+	complete(&queue->done);
+}
+
 static int
 mlx5e_nvmeotcp_ddp_teardown(struct net_device *netdev,
 			    struct sock *sk,
@@ -188,6 +769,27 @@ static const struct tcp_ddp_dev_ops mlx5e_nvmeotcp_ops = {
 	.tcp_ddp_resync = mlx5e_nvmeotcp_dev_resync,
 };
 
+struct mlx5e_nvmeotcp_queue *
+mlx5e_nvmeotcp_get_queue(struct mlx5e_nvmeotcp *nvmeotcp, int id)
+{
+	struct mlx5e_nvmeotcp_queue *queue;
+
+	rcu_read_lock();
+	queue = rhashtable_lookup_fast(&nvmeotcp->queue_hash,
+				       &id, rhash_queues);
+	if (queue && !IS_ERR(queue))
+		if (!refcount_inc_not_zero(&queue->ref_count))
+			queue = NULL;
+	rcu_read_unlock();
+	return queue;
+}
+
+void mlx5e_nvmeotcp_put_queue(struct mlx5e_nvmeotcp_queue *queue)
+{
+	if (refcount_dec_and_test(&queue->ref_count))
+		kfree(queue);
+}
+
 int set_feature_nvme_tcp(struct net_device *netdev, bool enable)
 {
 	struct mlx5e_priv *priv = netdev_priv(netdev);
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.h b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.h
index 753757fc44a3..d0e515502d6d 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.h
@@ -100,6 +100,10 @@ int mlx5e_nvmeotcp_init(struct mlx5e_priv *priv);
 int set_feature_nvme_tcp(struct net_device *netdev, bool enable);
 int set_feature_nvme_tcp_crc(struct net_device *netdev, bool enable);
 void mlx5e_nvmeotcp_cleanup(struct mlx5e_priv *priv);
+struct mlx5e_nvmeotcp_queue *
+mlx5e_nvmeotcp_get_queue(struct mlx5e_nvmeotcp *nvmeotcp, int id);
+void mlx5e_nvmeotcp_put_queue(struct mlx5e_nvmeotcp_queue *queue);
+void mlx5e_nvmeotcp_ctx_comp(struct mlx5e_icosq_wqe_info *wi);
 int mlx5e_nvmeotcp_init_rx(struct mlx5e_priv *priv);
 void mlx5e_nvmeotcp_cleanup_rx(struct mlx5e_priv *priv);
 #else
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp_utils.h b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp_utils.h
index 329e114d6571..44671e28a9ea 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp_utils.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp_utils.h
@@ -4,9 +4,77 @@
 #define __MLX5E_NVMEOTCP_UTILS_H__
 
 #include "en.h"
+#include "en_accel/nvmeotcp.h"
+
+enum {
+	MLX5E_NVMEOTCP_PROGRESS_PARAMS_PDU_TRACKER_STATE_START     = 0,
+	MLX5E_NVMEOTCP_PROGRESS_PARAMS_PDU_TRACKER_STATE_TRACKING  = 1,
+	MLX5E_NVMEOTCP_PROGRESS_PARAMS_PDU_TRACKER_STATE_SEARCHING = 2,
+};
+
+struct mlx5_seg_nvmeotcp_static_params {
+	u8     ctx[MLX5_ST_SZ_BYTES(transport_static_params)];
+};
+
+struct mlx5_seg_nvmeotcp_progress_params {
+	__be32 tir_num;
+	u8     ctx[MLX5_ST_SZ_BYTES(nvmeotcp_progress_params)];
+};
+
+struct mlx5e_set_nvmeotcp_static_params_wqe {
+	struct mlx5_wqe_ctrl_seg          ctrl;
+	struct mlx5_wqe_umr_ctrl_seg      uctrl;
+	struct mlx5_mkey_seg              mkc;
+	struct mlx5_seg_nvmeotcp_static_params params;
+};
+
+struct mlx5e_set_nvmeotcp_progress_params_wqe {
+	struct mlx5_wqe_ctrl_seg            ctrl;
+	struct mlx5_seg_nvmeotcp_progress_params params;
+};
+
+struct mlx5e_get_psv_wqe {
+	struct mlx5_wqe_ctrl_seg ctrl;
+	struct mlx5_seg_get_psv  psv;
+};
+
+///////////////////////////////////////////
+#define MLX5E_NVMEOTCP_STATIC_PARAMS_WQE_SZ \
+	(sizeof(struct mlx5e_set_nvmeotcp_static_params_wqe))
+
+#define MLX5E_NVMEOTCP_PROGRESS_PARAMS_WQE_SZ \
+	(sizeof(struct mlx5e_set_nvmeotcp_progress_params_wqe))
+#define MLX5E_NVMEOTCP_STATIC_PARAMS_OCTWORD_SIZE \
+	(MLX5_ST_SZ_BYTES(transport_static_params) / MLX5_SEND_WQE_DS)
+
+#define MLX5E_NVMEOTCP_STATIC_PARAMS_WQEBBS \
+	(DIV_ROUND_UP(MLX5E_NVMEOTCP_STATIC_PARAMS_WQE_SZ, MLX5_SEND_WQE_BB))
+#define MLX5E_NVMEOTCP_PROGRESS_PARAMS_WQEBBS \
+	(DIV_ROUND_UP(MLX5E_NVMEOTCP_PROGRESS_PARAMS_WQE_SZ, MLX5_SEND_WQE_BB))
+
+#define MLX5E_NVMEOTCP_FETCH_STATIC_PARAMS_WQE(sq, pi) \
+	((struct mlx5e_set_nvmeotcp_static_params_wqe *)\
+	 mlx5e_fetch_wqe(&(sq)->wq, pi, sizeof(struct mlx5e_set_nvmeotcp_static_params_wqe)))
+
+#define MLX5E_NVMEOTCP_FETCH_PROGRESS_PARAMS_WQE(sq, pi) \
+	((struct mlx5e_set_nvmeotcp_progress_params_wqe *)\
+	 mlx5e_fetch_wqe(&(sq)->wq, pi, sizeof(struct mlx5e_set_nvmeotcp_progress_params_wqe)))
 
 #define MLX5E_NVMEOTCP_FETCH_KLM_WQE(sq, pi) \
 	((struct mlx5e_umr_wqe *)\
 	 mlx5e_fetch_wqe(&(sq)->wq, pi, sizeof(struct mlx5e_umr_wqe)))
 
+#define MLX5_CTRL_SEGMENT_OPC_MOD_UMR_NVMEOTCP_TIR_PROGRESS_PARAMS 0x4
+
+void
+build_nvmeotcp_progress_params(struct mlx5e_nvmeotcp_queue *queue,
+			       struct mlx5e_set_nvmeotcp_progress_params_wqe *wqe,
+			       u32 seq);
+
+void
+build_nvmeotcp_static_params(struct mlx5e_nvmeotcp_queue *queue,
+			     struct mlx5e_set_nvmeotcp_static_params_wqe *wqe,
+			     u32 resync_seq,
+			     bool zerocopy, bool crc_rx);
+
 #endif /* __MLX5E_NVMEOTCP_UTILS_H__ */
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
index 28aa99265c0a..056fc24dd5ed 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
@@ -47,6 +47,7 @@
 #include "fpga/ipsec.h"
 #include "en_accel/ipsec_rxtx.h"
 #include "en_accel/tls_rxtx.h"
+#include "en_accel/nvmeotcp.h"
 #include "lib/clock.h"
 #include "en/xdp.h"
 #include "en/xsk/rx.h"
@@ -629,6 +630,9 @@ void mlx5e_free_icosq_descs(struct mlx5e_icosq *sq)
 #ifdef CONFIG_MLX5_EN_NVMEOTCP
 		case MLX5E_ICOSQ_WQE_UMR_NVME_TCP:
 			break;
+		case MLX5E_ICOSQ_WQE_SET_PSV_NVME_TCP:
+			mlx5e_nvmeotcp_ctx_comp(wi);
+			break;
 #endif
 		}
 	}
@@ -703,6 +707,9 @@ int mlx5e_poll_ico_cq(struct mlx5e_cq *cq)
 #ifdef CONFIG_MLX5_EN_NVMEOTCP
 			case MLX5E_ICOSQ_WQE_UMR_NVME_TCP:
 				break;
+			case MLX5E_ICOSQ_WQE_SET_PSV_NVME_TCP:
+				mlx5e_nvmeotcp_ctx_comp(wi);
+				break;
 #endif
 			default:
 				netdev_WARN_ONCE(cq->netdev,
-- 
2.24.1

[PATCH v2 net-next 17/21] net/mlx5e: NVMEoTCP async ddp invalidation

[Boris Pismenny]

From: Ben Ben-Ishay <benishay@nvidia.com>

Teardown ddp contexts asynchronously by posting a WQE, and calling back
to nvme-tcp when the corresponding CQE is received.

Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: Ben Ben-Ishay <benishay@nvidia.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Yoray Zack <yorayz@mellanox.com>
---
 .../net/ethernet/mellanox/mlx5/core/en/txrx.h |  4 ++
 .../mellanox/mlx5/core/en_accel/nvmeotcp.c    | 66 ++++++++++++++++---
 .../mellanox/mlx5/core/en_accel/nvmeotcp.h    |  1 +
 .../net/ethernet/mellanox/mlx5/core/en_rx.c   |  6 ++
 4 files changed, 69 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/txrx.h b/drivers/net/ethernet/mellanox/mlx5/core/en/txrx.h
index f00d76f1ded4..eb929edabd6b 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/txrx.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/txrx.h
@@ -36,6 +36,7 @@ enum mlx5e_icosq_wqe_type {
 #endif
 #ifdef CONFIG_MLX5_EN_NVMEOTCP
 	MLX5E_ICOSQ_WQE_UMR_NVME_TCP,
+	MLX5E_ICOSQ_WQE_UMR_NVME_TCP_INVALIDATE,
 	MLX5E_ICOSQ_WQE_SET_PSV_NVME_TCP,
 #endif
 };
@@ -184,6 +185,9 @@ struct mlx5e_icosq_wqe_info {
 		struct {
 			struct mlx5e_nvmeotcp_queue *queue;
 		} nvmeotcp_q;
+		struct {
+			struct nvmeotcp_queue_entry *entry;
+		} nvmeotcp_qe;
 #endif
 	};
 };
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.c b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.c
index 3a42477f1bd7..22fa1e9f3e7a 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.c
@@ -152,6 +152,7 @@ enum wqe_type {
 	BSF_KLM_UMR = 1,
 	SET_PSV_UMR = 2,
 	BSF_UMR = 3,
+	KLM_INV_UMR = 4,
 };
 
 static void
@@ -208,6 +209,13 @@ build_nvmeotcp_klm_umr(struct mlx5e_nvmeotcp_queue *queue,
 				   MLX5E_KLM_UMR_DS_CNT(ALIGN(klm_entries, KLM_ALIGNMENT)));
 	cseg->general_id = cpu_to_be32(id);
 
+	if (!klm_entries) { /* this is invalidate */
+		ucseg->mkey_mask = cpu_to_be64(MLX5_MKEY_MASK_FREE);
+		ucseg->flags = MLX5_UMR_INLINE;
+		mkc->status = MLX5_MKEY_STATUS_FREE;
+		return;
+	}
+
 	if (klm_type == KLM_UMR && !klm_offset) {
 		ucseg->mkey_mask |= cpu_to_be64(MLX5_MKEY_MASK_XLT_OCT_SIZE |
 						MLX5_MKEY_MASK_LEN | MLX5_MKEY_MASK_FREE);
@@ -306,8 +314,8 @@ build_nvmeotcp_static_params(struct mlx5e_nvmeotcp_queue *queue,
 
 static void
 mlx5e_nvmeotcp_fill_wi(struct mlx5e_nvmeotcp_queue *nvmeotcp_queue,
-		       struct mlx5e_icosq *sq, u32 wqe_bbs, u16 pi,
-		       enum wqe_type type)
+		       struct mlx5e_icosq *sq, u32 wqe_bbs,
+		       u16 pi, u16 ccid, enum wqe_type type)
 {
 	struct mlx5e_icosq_wqe_info *wi = &sq->db.wqe_info[pi];
 
@@ -316,12 +324,17 @@ mlx5e_nvmeotcp_fill_wi(struct mlx5e_nvmeotcp_queue *nvmeotcp_queue,
 	case SET_PSV_UMR:
 		wi->wqe_type = MLX5E_ICOSQ_WQE_SET_PSV_NVME_TCP;
 		break;
+	case KLM_INV_UMR:
+		wi->wqe_type = MLX5E_ICOSQ_WQE_UMR_NVME_TCP_INVALIDATE;
+		break;
 	default:
 		wi->wqe_type = MLX5E_ICOSQ_WQE_UMR_NVME_TCP;
 		break;
 	}
 
-	if (type == SET_PSV_UMR)
+	if (type == KLM_INV_UMR)
+		wi->nvmeotcp_qe.entry = &nvmeotcp_queue->ccid_table[ccid];
+	else if (type == SET_PSV_UMR)
 		wi->nvmeotcp_q.queue = nvmeotcp_queue;
 }
 
@@ -336,7 +349,7 @@ mlx5e_nvmeotcp_rx_post_static_params_wqe(struct mlx5e_nvmeotcp_queue *queue,
 	wqe_bbs = MLX5E_NVMEOTCP_STATIC_PARAMS_WQEBBS;
 	pi = mlx5e_icosq_get_next_pi(sq, wqe_bbs);
 	wqe = MLX5E_NVMEOTCP_FETCH_STATIC_PARAMS_WQE(sq, pi);
-	mlx5e_nvmeotcp_fill_wi(NULL, sq, wqe_bbs, pi, BSF_UMR);
+	mlx5e_nvmeotcp_fill_wi(NULL, sq, wqe_bbs, pi, 0, BSF_UMR);
 	build_nvmeotcp_static_params(queue, wqe, resync_seq, queue->zerocopy, queue->crc_rx);
 	sq->pc += wqe_bbs;
 	mlx5e_notify_hw(&sq->wq, sq->pc, sq->uar_map, &wqe->ctrl);
@@ -353,7 +366,7 @@ mlx5e_nvmeotcp_rx_post_progress_params_wqe(struct mlx5e_nvmeotcp_queue *queue,
 	wqe_bbs = MLX5E_NVMEOTCP_PROGRESS_PARAMS_WQEBBS;
 	pi = mlx5e_icosq_get_next_pi(sq, wqe_bbs);
 	wqe = MLX5E_NVMEOTCP_FETCH_PROGRESS_PARAMS_WQE(sq, pi);
-	mlx5e_nvmeotcp_fill_wi(queue, sq, wqe_bbs, pi, SET_PSV_UMR);
+	mlx5e_nvmeotcp_fill_wi(queue, sq, wqe_bbs, pi, 0, SET_PSV_UMR);
 	build_nvmeotcp_progress_params(queue, wqe, seq);
 	sq->pc += wqe_bbs;
 	mlx5e_notify_hw(&sq->wq, sq->pc, sq->uar_map, &wqe->ctrl);
@@ -377,7 +390,8 @@ post_klm_wqe(struct mlx5e_nvmeotcp_queue *queue,
 	wqe_bbs = DIV_ROUND_UP(wqe_sz, MLX5_SEND_WQE_BB);
 	pi = mlx5e_icosq_get_next_pi(sq, wqe_bbs);
 	wqe = MLX5E_NVMEOTCP_FETCH_KLM_WQE(sq, pi);
-	mlx5e_nvmeotcp_fill_wi(queue, sq, wqe_bbs, pi, wqe_type);
+	mlx5e_nvmeotcp_fill_wi(queue, sq, wqe_bbs, pi, ccid,
+			       klm_length ? KLM_UMR : KLM_INV_UMR);
 	build_nvmeotcp_klm_umr(queue, wqe, ccid, cur_klm_entries, *klm_offset,
 			       klm_length, wqe_type);
 	*klm_offset += cur_klm_entries;
@@ -395,8 +409,13 @@ mlx5e_nvmeotcp_post_klm_wqe(struct mlx5e_nvmeotcp_queue *queue,
 	struct mlx5e_icosq *sq = &queue->sq->icosq;
 
 	/* TODO: set stricter wqe_sz; using max for now */
-	wqes = DIV_ROUND_UP(klm_length, queue->max_klms_per_wqe);
-	wqe_sz = MLX5E_KLM_UMR_WQE_SZ(queue->max_klms_per_wqe);
+	if (klm_length == 0) {
+		wqes = 1;
+		wqe_sz = MLX5E_NVMEOTCP_STATIC_PARAMS_WQEBBS;
+	} else {
+		wqes = DIV_ROUND_UP(klm_length, queue->max_klms_per_wqe);
+		wqe_sz = MLX5E_KLM_UMR_WQE_SZ(queue->max_klms_per_wqe);
+	}
 
 	max_wqe_bbs = DIV_ROUND_UP(wqe_sz, MLX5_SEND_WQE_BB);
 
@@ -735,6 +754,24 @@ mlx5e_nvmeotcp_ddp_setup(struct net_device *netdev,
 	return 0;
 }
 
+void mlx5e_nvmeotcp_ddp_inv_done(struct mlx5e_icosq_wqe_info *wi)
+{
+	struct nvmeotcp_queue_entry *q_entry = wi->nvmeotcp_qe.entry;
+	struct mlx5e_nvmeotcp_queue *queue = q_entry->queue;
+	struct mlx5_core_dev *mdev = queue->priv->mdev;
+	struct tcp_ddp_io *ddp = q_entry->ddp;
+	const struct tcp_ddp_ulp_ops *ulp_ops;
+
+	dma_unmap_sg(mdev->device, ddp->sg_table.sgl,
+		     q_entry->sgl_length, DMA_FROM_DEVICE);
+
+	q_entry->sgl_length = 0;
+
+	ulp_ops = inet_csk(queue->sk)->icsk_ulp_ddp_ops;
+	if (ulp_ops && ulp_ops->ddp_teardown_done)
+		ulp_ops->ddp_teardown_done(q_entry->ddp_ctx);
+}
+
 void mlx5e_nvmeotcp_ctx_comp(struct mlx5e_icosq_wqe_info *wi)
 {
 	struct mlx5e_nvmeotcp_queue *queue = wi->nvmeotcp_q.queue;
@@ -751,6 +788,19 @@ mlx5e_nvmeotcp_ddp_teardown(struct net_device *netdev,
 			    struct tcp_ddp_io *ddp,
 			    void *ddp_ctx)
 {
+	struct mlx5e_nvmeotcp_queue *queue =
+		(struct mlx5e_nvmeotcp_queue *)tcp_ddp_get_ctx(sk);
+	struct mlx5e_priv *priv = netdev_priv(netdev);
+	struct nvmeotcp_queue_entry *q_entry;
+
+	q_entry  = &queue->ccid_table[ddp->command_id];
+	WARN_ON(q_entry->sgl_length == 0);
+
+	q_entry->ddp_ctx = ddp_ctx;
+	q_entry->queue = queue;
+
+	mlx5e_nvmeotcp_post_klm_wqe(queue, KLM_UMR, ddp->command_id, 0);
+
 	return 0;
 }
 
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.h b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.h
index d0e515502d6d..5a613addfc7c 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.h
@@ -103,6 +103,7 @@ void mlx5e_nvmeotcp_cleanup(struct mlx5e_priv *priv);
 struct mlx5e_nvmeotcp_queue *
 mlx5e_nvmeotcp_get_queue(struct mlx5e_nvmeotcp *nvmeotcp, int id);
 void mlx5e_nvmeotcp_put_queue(struct mlx5e_nvmeotcp_queue *queue);
+void mlx5e_nvmeotcp_ddp_inv_done(struct mlx5e_icosq_wqe_info *wi);
 void mlx5e_nvmeotcp_ctx_comp(struct mlx5e_icosq_wqe_info *wi);
 int mlx5e_nvmeotcp_init_rx(struct mlx5e_priv *priv);
 void mlx5e_nvmeotcp_cleanup_rx(struct mlx5e_priv *priv);
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
index 056fc24dd5ed..598d62366af2 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
@@ -630,6 +630,9 @@ void mlx5e_free_icosq_descs(struct mlx5e_icosq *sq)
 #ifdef CONFIG_MLX5_EN_NVMEOTCP
 		case MLX5E_ICOSQ_WQE_UMR_NVME_TCP:
 			break;
+		case MLX5E_ICOSQ_WQE_UMR_NVME_TCP_INVALIDATE:
+			mlx5e_nvmeotcp_ddp_inv_done(wi);
+			break;
 		case MLX5E_ICOSQ_WQE_SET_PSV_NVME_TCP:
 			mlx5e_nvmeotcp_ctx_comp(wi);
 			break;
@@ -707,6 +710,9 @@ int mlx5e_poll_ico_cq(struct mlx5e_cq *cq)
 #ifdef CONFIG_MLX5_EN_NVMEOTCP
 			case MLX5E_ICOSQ_WQE_UMR_NVME_TCP:
 				break;
+			case MLX5E_ICOSQ_WQE_UMR_NVME_TCP_INVALIDATE:
+				mlx5e_nvmeotcp_ddp_inv_done(wi);
+				break;
 			case MLX5E_ICOSQ_WQE_SET_PSV_NVME_TCP:
 				mlx5e_nvmeotcp_ctx_comp(wi);
 				break;
-- 
2.24.1

[PATCH v2 net-next 18/21] net/mlx5e: NVMEoTCP ddp setup and resync

[Boris Pismenny]

From: Ben Ben-Ishay <benishay@nvidia.com>

NVMEoTCP offload uses buffer registration for every NVME request to perform direct data placement,
The registration is done via KLM UMR WQE's.
The driver resync handler advertise the software resync response via static params WQE.

Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: Ben Ben-Ishay <benishay@nvidia.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Yoray Zack <yorayz@mellanox.com>
---
 .../mellanox/mlx5/core/en_accel/nvmeotcp.c    | 33 +++++++++++++++++--
 1 file changed, 31 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.c b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.c
index 22fa1e9f3e7a..c2967cb4cb6a 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.c
@@ -751,6 +751,30 @@ mlx5e_nvmeotcp_ddp_setup(struct net_device *netdev,
 			 struct sock *sk,
 			 struct tcp_ddp_io *ddp)
 {
+	struct mlx5e_priv *priv = netdev_priv(netdev);
+	struct scatterlist *sg = ddp->sg_table.sgl;
+	struct mlx5e_nvmeotcp_queue *queue;
+	struct mlx5_core_dev *mdev;
+	int i, size = 0, count = 0;
+
+	queue = container_of(tcp_ddp_get_ctx(sk), struct mlx5e_nvmeotcp_queue, tcp_ddp_ctx);
+
+	mdev = queue->priv->mdev;
+	count = dma_map_sg(mdev->device, ddp->sg_table.sgl, ddp->nents,
+			   DMA_FROM_DEVICE);
+
+	if (WARN_ON(count > mlx5e_get_max_sgl(mdev)))
+		return -ENOSPC;
+
+	for (i = 0; i < count; i++)
+		size += sg[i].length;
+
+	queue->ccid_table[ddp->command_id].size = size;
+	queue->ccid_table[ddp->command_id].ddp = ddp;
+	queue->ccid_table[ddp->command_id].sgl = sg;
+	queue->ccid_table[ddp->command_id].ccid_gen++;
+	queue->ccid_table[ddp->command_id].sgl_length = count;
+
 	return 0;
 }
 
@@ -788,11 +812,11 @@ mlx5e_nvmeotcp_ddp_teardown(struct net_device *netdev,
 			    struct tcp_ddp_io *ddp,
 			    void *ddp_ctx)
 {
-	struct mlx5e_nvmeotcp_queue *queue =
-		(struct mlx5e_nvmeotcp_queue *)tcp_ddp_get_ctx(sk);
+	struct mlx5e_nvmeotcp_queue *queue;
 	struct mlx5e_priv *priv = netdev_priv(netdev);
 	struct nvmeotcp_queue_entry *q_entry;
 
+	queue = container_of(tcp_ddp_get_ctx(sk), struct mlx5e_nvmeotcp_queue, tcp_ddp_ctx);
 	q_entry  = &queue->ccid_table[ddp->command_id];
 	WARN_ON(q_entry->sgl_length == 0);
 
@@ -808,6 +832,11 @@ static void
 mlx5e_nvmeotcp_dev_resync(struct net_device *netdev,
 			  struct sock *sk, u32 seq)
 {
+	struct mlx5e_nvmeotcp_queue *queue =
+		container_of(tcp_ddp_get_ctx(sk), struct mlx5e_nvmeotcp_queue, tcp_ddp_ctx);
+
+	queue->after_resync_cqe = 1;
+	mlx5e_nvmeotcp_rx_post_static_params_wqe(queue, seq);
 }
 
 static const struct tcp_ddp_dev_ops mlx5e_nvmeotcp_ops = {
-- 
2.24.1

[PATCH v2 net-next 19/21] net/mlx5e: NVMEoTCP, data-path for DDP offload

[Boris Pismenny]

From: Ben Ben-Ishay <benishay@nvidia.com>

NVMEoTCP direct data placement constructs an SKB from each CQE, while
pointing at NVME buffers.

This enables the offload, as the NVMe-TCP layer will skip the copy when
src == dst.

Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: Ben Ben-Ishay <benishay@nvidia.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Yoray Zack <yorayz@mellanox.com>
---
 .../net/ethernet/mellanox/mlx5/core/Makefile  |   2 +-
 drivers/net/ethernet/mellanox/mlx5/core/en.h  |   1 +
 .../ethernet/mellanox/mlx5/core/en/xsk/rx.c   |   1 +
 .../ethernet/mellanox/mlx5/core/en/xsk/rx.h   |   1 +
 .../mlx5/core/en_accel/nvmeotcp_rxtx.c        | 243 ++++++++++++++++++
 .../mlx5/core/en_accel/nvmeotcp_rxtx.h        |  43 ++++
 .../net/ethernet/mellanox/mlx5/core/en_rx.c   |  41 ++-
 7 files changed, 325 insertions(+), 7 deletions(-)
 create mode 100644 drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp_rxtx.c
 create mode 100644 drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp_rxtx.h

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/Makefile b/drivers/net/ethernet/mellanox/mlx5/core/Makefile
index ada8cd22f8fb..fe22895ab1ee 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/Makefile
+++ b/drivers/net/ethernet/mellanox/mlx5/core/Makefile
@@ -97,4 +97,4 @@ mlx5_core-$(CONFIG_MLX5_SF) += sf/vhca_event.o sf/dev/dev.o sf/dev/driver.o
 #
 mlx5_core-$(CONFIG_MLX5_SF_MANAGER) += sf/cmd.o sf/hw_table.o sf/devlink.o
 
-mlx5_core-$(CONFIG_MLX5_EN_NVMEOTCP) += en_accel/fs_tcp.o en_accel/nvmeotcp.o
+mlx5_core-$(CONFIG_MLX5_EN_NVMEOTCP) += en_accel/fs_tcp.o en_accel/nvmeotcp.o en_accel/nvmeotcp_rxtx.o
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en.h b/drivers/net/ethernet/mellanox/mlx5/core/en.h
index dc6ebcfffb1b..f41eb807d026 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en.h
@@ -573,6 +573,7 @@ struct mlx5e_rq;
 typedef void (*mlx5e_fp_handle_rx_cqe)(struct mlx5e_rq*, struct mlx5_cqe64*);
 typedef struct sk_buff *
 (*mlx5e_fp_skb_from_cqe_mpwrq)(struct mlx5e_rq *rq, struct mlx5e_mpw_info *wi,
+			       struct mlx5_cqe64 *cqe,
 			       u16 cqe_bcnt, u32 head_offset, u32 page_idx);
 typedef struct sk_buff *
 (*mlx5e_fp_skb_from_cqe)(struct mlx5e_rq *rq, struct mlx5_cqe64 *cqe,
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/rx.c
index 8e7b877d8a12..9a6fbd1b1c34 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/rx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/rx.c
@@ -25,6 +25,7 @@ static struct sk_buff *mlx5e_xsk_construct_skb(struct mlx5e_rq *rq, void *data,
 
 struct sk_buff *mlx5e_xsk_skb_from_cqe_mpwrq_linear(struct mlx5e_rq *rq,
 						    struct mlx5e_mpw_info *wi,
+						    struct mlx5_cqe64 *cqe,
 						    u16 cqe_bcnt,
 						    u32 head_offset,
 						    u32 page_idx)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/rx.h b/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/rx.h
index 7f88ccf67fdd..112c5b3ec165 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/rx.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/rx.h
@@ -11,6 +11,7 @@
 
 struct sk_buff *mlx5e_xsk_skb_from_cqe_mpwrq_linear(struct mlx5e_rq *rq,
 						    struct mlx5e_mpw_info *wi,
+						    struct mlx5_cqe64 *cqe,
 						    u16 cqe_bcnt,
 						    u32 head_offset,
 						    u32 page_idx);
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp_rxtx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp_rxtx.c
new file mode 100644
index 000000000000..f446b5d56d64
--- /dev/null
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp_rxtx.c
@@ -0,0 +1,243 @@
+// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
+/* Copyright (c) 2021 Mellanox Technologies. */
+
+#include "en_accel/nvmeotcp_rxtx.h"
+#include "en_accel/nvmeotcp.h"
+#include <linux/mlx5/mlx5_ifc.h>
+
+#define	MLX5E_TC_FLOW_ID_MASK  0x00ffffff
+static void nvmeotcp_update_resync(struct mlx5e_nvmeotcp_queue *queue,
+				   struct mlx5e_cqe128 *cqe128)
+{
+	const struct tcp_ddp_ulp_ops *ulp_ops;
+	u32 seq;
+
+	seq = be32_to_cpu(cqe128->resync_tcp_sn);
+	ulp_ops = inet_csk(queue->sk)->icsk_ulp_ddp_ops;
+	if (ulp_ops && ulp_ops->resync_request)
+		ulp_ops->resync_request(queue->sk, seq, TCP_DDP_RESYNC_REQ);
+}
+
+static void mlx5e_nvmeotcp_advance_sgl_iter(struct mlx5e_nvmeotcp_queue *queue)
+{
+	struct nvmeotcp_queue_entry *nqe = &queue->ccid_table[queue->ccid];
+
+	queue->ccoff += nqe->sgl[queue->ccsglidx].length;
+	queue->ccoff_inner = 0;
+	queue->ccsglidx++;
+}
+
+static inline void
+mlx5e_nvmeotcp_add_skb_frag(struct net_device *netdev, struct sk_buff *skb,
+			    struct mlx5e_nvmeotcp_queue *queue,
+			    struct nvmeotcp_queue_entry *nqe, u32 fragsz)
+{
+	dma_sync_single_for_cpu(&netdev->dev,
+				nqe->sgl[queue->ccsglidx].offset + queue->ccoff_inner,
+				fragsz, DMA_FROM_DEVICE);
+	page_ref_inc(compound_head(sg_page(&nqe->sgl[queue->ccsglidx])));
+	// XXX: consider reducing the truesize, as no new memory is consumed
+	skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
+			sg_page(&nqe->sgl[queue->ccsglidx]),
+			nqe->sgl[queue->ccsglidx].offset + queue->ccoff_inner,
+			fragsz,
+			fragsz);
+}
+
+static struct sk_buff*
+mlx5_nvmeotcp_add_tail_nonlinear(struct mlx5e_nvmeotcp_queue *queue,
+				 struct sk_buff *skb, skb_frag_t *org_frags,
+				 int org_nr_frags, int frag_index)
+{
+	struct mlx5e_priv *priv = queue->priv;
+
+	while (org_nr_frags != frag_index) {
+		if (skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS) {
+			dev_kfree_skb_any(skb);
+			return NULL;
+		}
+		skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
+				skb_frag_page(&org_frags[frag_index]),
+				skb_frag_off(&org_frags[frag_index]),
+				skb_frag_size(&org_frags[frag_index]),
+				skb_frag_size(&org_frags[frag_index]));
+		page_ref_inc(skb_frag_page(&org_frags[frag_index]));
+		frag_index++;
+	}
+	return skb;
+}
+
+static struct sk_buff*
+mlx5_nvmeotcp_add_tail(struct mlx5e_nvmeotcp_queue *queue, struct sk_buff *skb,
+		       int offset, int len)
+{
+	struct mlx5e_priv *priv = queue->priv;
+
+	if (skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS) {
+		dev_kfree_skb_any(skb);
+		return NULL;
+	}
+	skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
+			virt_to_page(skb->data),
+			offset,
+			len,
+			len);
+	page_ref_inc(virt_to_page(skb->data));
+	return skb;
+}
+
+static void mlx5_nvmeotcp_trim_nonlinear(struct sk_buff *skb,
+					 skb_frag_t *org_frags,
+					 int *frag_index,
+					 int remaining)
+{
+	unsigned int frag_size;
+	int nr_frags;
+
+	/* skip @remaining bytes in frags */
+	*frag_index = 0;
+	while (remaining) {
+		frag_size = skb_frag_size(&skb_shinfo(skb)->frags[*frag_index]);
+		if (frag_size > remaining) {
+			skb_frag_off_add(&skb_shinfo(skb)->frags[*frag_index],
+					 remaining);
+			skb_frag_size_sub(&skb_shinfo(skb)->frags[*frag_index],
+					  remaining);
+			remaining = 0;
+		} else {
+			remaining -= frag_size;
+			skb_frag_unref(skb, *frag_index);
+			*frag_index += 1;
+		}
+	}
+
+	/* save original frags for the tail and unref */
+	nr_frags = skb_shinfo(skb)->nr_frags;
+	memcpy(&org_frags[*frag_index], &skb_shinfo(skb)->frags[*frag_index],
+	       (nr_frags - *frag_index) * sizeof(skb_frag_t));
+	while (--nr_frags >= *frag_index)
+		skb_frag_unref(skb, nr_frags);
+
+	/* remove frags from skb */
+	skb_shinfo(skb)->nr_frags = 0;
+	skb->len -= skb->data_len;
+	skb->truesize -= skb->data_len;
+	skb->data_len = 0;
+}
+
+struct sk_buff*
+mlx5e_nvmeotcp_handle_rx_skb(struct net_device *netdev, struct sk_buff *skb,
+			     struct mlx5_cqe64 *cqe, u32 cqe_bcnt,
+			     bool linear)
+{
+	int ccoff, cclen, hlen, ccid, remaining, fragsz, to_copy = 0;
+	struct mlx5e_priv *priv = netdev_priv(netdev);
+	skb_frag_t org_frags[MAX_SKB_FRAGS];
+	struct mlx5e_nvmeotcp_queue *queue;
+	struct nvmeotcp_queue_entry *nqe;
+	int org_nr_frags, frag_index;
+	struct mlx5e_cqe128 *cqe128;
+	u32 queue_id;
+
+	queue_id = (be32_to_cpu(cqe->sop_drop_qpn) & MLX5E_TC_FLOW_ID_MASK);
+	queue = mlx5e_nvmeotcp_get_queue(priv->nvmeotcp, queue_id);
+	if (unlikely(!queue)) {
+		dev_kfree_skb_any(skb);
+		return NULL;
+	}
+
+	cqe128 = container_of(cqe, struct mlx5e_cqe128, cqe64);
+	if (cqe_is_nvmeotcp_resync(cqe)) {
+		nvmeotcp_update_resync(queue, cqe128);
+		mlx5e_nvmeotcp_put_queue(queue);
+		return skb;
+	}
+
+#ifdef CONFIG_TCP_DDP_CRC
+	/* If a resync occurred in the previous cqe,
+	 * the current cqe.crcvalid bit may not be valid,
+	 * so we will treat it as 0
+	 */
+	skb->ddp_crc = queue->after_resync_cqe ? 0 :
+		cqe_is_nvmeotcp_crcvalid(cqe);
+	queue->after_resync_cqe = 0;
+#endif
+	if (!cqe_is_nvmeotcp_zc(cqe)) {
+		mlx5e_nvmeotcp_put_queue(queue);
+		return skb;
+	}
+
+	/* cc ddp from cqe */
+	ccid = be16_to_cpu(cqe128->ccid);
+	ccoff = be32_to_cpu(cqe128->ccoff);
+	cclen = be16_to_cpu(cqe128->cclen);
+	hlen  = be16_to_cpu(cqe128->hlen);
+
+	/* carve a hole in the skb for DDP data */
+	if (linear) {
+		skb_trim(skb, hlen);
+	} else {
+		org_nr_frags = skb_shinfo(skb)->nr_frags;
+		mlx5_nvmeotcp_trim_nonlinear(skb, org_frags, &frag_index,
+					     cclen);
+	}
+
+	nqe = &queue->ccid_table[ccid];
+
+	/* packet starts new ccid? */
+	if (queue->ccid != ccid || queue->ccid_gen != nqe->ccid_gen) {
+		queue->ccid = ccid;
+		queue->ccoff = 0;
+		queue->ccoff_inner = 0;
+		queue->ccsglidx = 0;
+		queue->ccid_gen = nqe->ccid_gen;
+	}
+
+	/* skip inside cc until the ccoff in the cqe */
+	while (queue->ccoff + queue->ccoff_inner < ccoff) {
+		remaining = nqe->sgl[queue->ccsglidx].length - queue->ccoff_inner;
+		fragsz = min_t(off_t, remaining,
+			       ccoff - (queue->ccoff + queue->ccoff_inner));
+
+		if (fragsz == remaining)
+			mlx5e_nvmeotcp_advance_sgl_iter(queue);
+		else
+			queue->ccoff_inner += fragsz;
+	}
+
+	/* adjust the skb according to the cqe cc */
+	while (to_copy < cclen) {
+		if (skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS) {
+			dev_kfree_skb_any(skb);
+			mlx5e_nvmeotcp_put_queue(queue);
+			return NULL;
+		}
+
+		remaining = nqe->sgl[queue->ccsglidx].length - queue->ccoff_inner;
+		fragsz = min_t(int, remaining, cclen - to_copy);
+
+		mlx5e_nvmeotcp_add_skb_frag(netdev, skb, queue, nqe, fragsz);
+		to_copy += fragsz;
+		if (fragsz == remaining)
+			mlx5e_nvmeotcp_advance_sgl_iter(queue);
+		else
+			queue->ccoff_inner += fragsz;
+	}
+
+	if (cqe_bcnt > hlen + cclen) {
+		remaining = cqe_bcnt - hlen - cclen;
+		if (linear)
+			skb = mlx5_nvmeotcp_add_tail(queue, skb,
+						     offset_in_page(skb->data) +
+								hlen + cclen,
+						     remaining);
+		else
+			skb = mlx5_nvmeotcp_add_tail_nonlinear(queue, skb,
+							       org_frags,
+							       org_nr_frags,
+							       frag_index);
+	}
+
+	mlx5e_nvmeotcp_put_queue(queue);
+	return skb;
+}
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp_rxtx.h b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp_rxtx.h
new file mode 100644
index 000000000000..65456b46c33f
--- /dev/null
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp_rxtx.h
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
+/* Copyright (c) 2021 Mellanox Technologies. */
+#ifndef __MLX5E_NVMEOTCP_RXTX_H__
+#define __MLX5E_NVMEOTCP_RXTX_H__
+
+#ifdef CONFIG_MLX5_EN_NVMEOTCP
+
+#include <linux/skbuff.h>
+#include "en.h"
+
+struct sk_buff*
+mlx5e_nvmeotcp_handle_rx_skb(struct net_device *netdev, struct sk_buff *skb,
+			     struct mlx5_cqe64 *cqe, u32 cqe_bcnt, bool linear);
+
+static inline int mlx5_nvmeotcp_get_headlen(struct mlx5_cqe64 *cqe, u32 cqe_bcnt)
+{
+	struct mlx5e_cqe128 *cqe128;
+
+	if (!cqe_is_nvmeotcp_zc(cqe) || cqe_is_nvmeotcp_resync(cqe))
+		return cqe_bcnt;
+
+	cqe128 = container_of(cqe, struct mlx5e_cqe128, cqe64);
+	return be16_to_cpu(cqe128->hlen);
+}
+
+#else
+static inline struct sk_buff*
+mlx5e_nvmeotcp_handle_rx_skb(struct net_device *netdev, struct sk_buff *skb,
+			     struct mlx5_cqe64 *cqe, u32 cqe_bcnt, bool linear)
+{ return skb; }
+
+static inline int mlx5_nvmeotcp_get_headlen(struct mlx5_cqe64 *cqe, u32 cqe_bcnt)
+{ return cqe_bcnt; }
+
+#endif /* CONFIG_MLX5_EN_NVMEOTCP */
+
+static inline u16 mlx5e_get_headlen_hint(struct mlx5_cqe64 *cqe, u32 cqe_bcnt)
+{
+	return min_t(u32, MLX5E_RX_MAX_HEAD, mlx5_nvmeotcp_get_headlen(cqe, cqe_bcnt));
+}
+
+
+#endif /* __MLX5E_NVMEOTCP_RXTX_H__ */
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
index 598d62366af2..168a4f490b8d 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
@@ -48,6 +48,7 @@
 #include "en_accel/ipsec_rxtx.h"
 #include "en_accel/tls_rxtx.h"
 #include "en_accel/nvmeotcp.h"
+#include "en_accel/nvmeotcp_rxtx.h"
 #include "lib/clock.h"
 #include "en/xdp.h"
 #include "en/xsk/rx.h"
@@ -57,9 +58,11 @@
 
 static struct sk_buff *
 mlx5e_skb_from_cqe_mpwrq_linear(struct mlx5e_rq *rq, struct mlx5e_mpw_info *wi,
+				struct mlx5_cqe64 *cqe,
 				u16 cqe_bcnt, u32 head_offset, u32 page_idx);
 static struct sk_buff *
 mlx5e_skb_from_cqe_mpwrq_nonlinear(struct mlx5e_rq *rq, struct mlx5e_mpw_info *wi,
+				   struct mlx5_cqe64 *cqe,
 				   u16 cqe_bcnt, u32 head_offset, u32 page_idx);
 static void mlx5e_handle_rx_cqe(struct mlx5e_rq *rq, struct mlx5_cqe64 *cqe);
 static void mlx5e_handle_rx_cqe_mpwrq(struct mlx5e_rq *rq, struct mlx5_cqe64 *cqe);
@@ -1189,6 +1192,12 @@ mlx5e_skb_from_cqe_linear(struct mlx5e_rq *rq, struct mlx5_cqe64 *cqe,
 	/* queue up for recycling/reuse */
 	page_ref_inc(di->page);
 
+#if defined(CONFIG_TCP_DDP) && defined(CONFIG_MLX5_EN_NVMEOTCP)
+	if (cqe_is_nvmeotcp(cqe))
+		skb = mlx5e_nvmeotcp_handle_rx_skb(rq->netdev, skb, cqe,
+						   cqe_bcnt, true);
+#endif
+
 	return skb;
 }
 
@@ -1197,8 +1206,8 @@ mlx5e_skb_from_cqe_nonlinear(struct mlx5e_rq *rq, struct mlx5_cqe64 *cqe,
 			     struct mlx5e_wqe_frag_info *wi, u32 cqe_bcnt)
 {
 	struct mlx5e_rq_frag_info *frag_info = &rq->wqe.info.arr[0];
+	u16 headlen = mlx5e_get_headlen_hint(cqe, cqe_bcnt);
 	struct mlx5e_wqe_frag_info *head_wi = wi;
-	u16 headlen      = min_t(u32, MLX5E_RX_MAX_HEAD, cqe_bcnt);
 	u16 frag_headlen = headlen;
 	u16 byte_cnt     = cqe_bcnt - headlen;
 	struct sk_buff *skb;
@@ -1207,7 +1216,7 @@ mlx5e_skb_from_cqe_nonlinear(struct mlx5e_rq *rq, struct mlx5_cqe64 *cqe,
 	 * might spread among multiple pages.
 	 */
 	skb = napi_alloc_skb(rq->cq.napi,
-			     ALIGN(MLX5E_RX_MAX_HEAD, sizeof(long)));
+			     ALIGN(headlen, sizeof(long)));
 	if (unlikely(!skb)) {
 		rq->stats->buff_alloc_err++;
 		return NULL;
@@ -1233,6 +1242,12 @@ mlx5e_skb_from_cqe_nonlinear(struct mlx5e_rq *rq, struct mlx5_cqe64 *cqe,
 	skb->tail += headlen;
 	skb->len  += headlen;
 
+#if defined(CONFIG_TCP_DDP) && defined(CONFIG_MLX5_EN_NVMEOTCP)
+	if (cqe_is_nvmeotcp(cqe))
+		skb = mlx5e_nvmeotcp_handle_rx_skb(rq->netdev, skb, cqe,
+						   cqe_bcnt, false);
+#endif
+
 	return skb;
 }
 
@@ -1387,7 +1402,7 @@ static void mlx5e_handle_rx_cqe_mpwrq_rep(struct mlx5e_rq *rq, struct mlx5_cqe64
 	skb = INDIRECT_CALL_2(rq->mpwqe.skb_from_cqe_mpwrq,
 			      mlx5e_skb_from_cqe_mpwrq_linear,
 			      mlx5e_skb_from_cqe_mpwrq_nonlinear,
-			      rq, wi, cqe_bcnt, head_offset, page_idx);
+			      rq, wi, cqe, cqe_bcnt, head_offset, page_idx);
 	if (!skb)
 		goto mpwrq_cqe_out;
 
@@ -1418,17 +1433,18 @@ const struct mlx5e_rx_handlers mlx5e_rx_handlers_rep = {
 
 static struct sk_buff *
 mlx5e_skb_from_cqe_mpwrq_nonlinear(struct mlx5e_rq *rq, struct mlx5e_mpw_info *wi,
+				   struct mlx5_cqe64 *cqe,
 				   u16 cqe_bcnt, u32 head_offset, u32 page_idx)
 {
-	u16 headlen = min_t(u16, MLX5E_RX_MAX_HEAD, cqe_bcnt);
 	struct mlx5e_dma_info *di = &wi->umr.dma_info[page_idx];
+	u16 headlen = mlx5e_get_headlen_hint(cqe, cqe_bcnt);
 	u32 frag_offset    = head_offset + headlen;
 	u32 byte_cnt       = cqe_bcnt - headlen;
 	struct mlx5e_dma_info *head_di = di;
 	struct sk_buff *skb;
 
 	skb = napi_alloc_skb(rq->cq.napi,
-			     ALIGN(MLX5E_RX_MAX_HEAD, sizeof(long)));
+			     ALIGN(headlen, sizeof(long)));
 	if (unlikely(!skb)) {
 		rq->stats->buff_alloc_err++;
 		return NULL;
@@ -1459,11 +1475,18 @@ mlx5e_skb_from_cqe_mpwrq_nonlinear(struct mlx5e_rq *rq, struct mlx5e_mpw_info *w
 	skb->tail += headlen;
 	skb->len  += headlen;
 
+#if defined(CONFIG_TCP_DDP) && defined(CONFIG_MLX5_EN_NVMEOTCP)
+	if (cqe_is_nvmeotcp(cqe))
+		skb = mlx5e_nvmeotcp_handle_rx_skb(rq->netdev, skb, cqe,
+						   cqe_bcnt, false);
+#endif
+
 	return skb;
 }
 
 static struct sk_buff *
 mlx5e_skb_from_cqe_mpwrq_linear(struct mlx5e_rq *rq, struct mlx5e_mpw_info *wi,
+				struct mlx5_cqe64 *cqe,
 				u16 cqe_bcnt, u32 head_offset, u32 page_idx)
 {
 	struct mlx5e_dma_info *di = &wi->umr.dma_info[page_idx];
@@ -1505,6 +1528,12 @@ mlx5e_skb_from_cqe_mpwrq_linear(struct mlx5e_rq *rq, struct mlx5e_mpw_info *wi,
 	/* queue up for recycling/reuse */
 	page_ref_inc(di->page);
 
+#if defined(CONFIG_TCP_DDP) && defined(CONFIG_MLX5_EN_NVMEOTCP)
+	if (cqe_is_nvmeotcp(cqe))
+		skb = mlx5e_nvmeotcp_handle_rx_skb(rq->netdev, skb, cqe,
+						   cqe_bcnt, true);
+#endif
+
 	return skb;
 }
 
@@ -1543,7 +1572,7 @@ static void mlx5e_handle_rx_cqe_mpwrq(struct mlx5e_rq *rq, struct mlx5_cqe64 *cq
 	skb = INDIRECT_CALL_2(rq->mpwqe.skb_from_cqe_mpwrq,
 			      mlx5e_skb_from_cqe_mpwrq_linear,
 			      mlx5e_skb_from_cqe_mpwrq_nonlinear,
-			      rq, wi, cqe_bcnt, head_offset, page_idx);
+			      rq, wi, cqe, cqe_bcnt, head_offset, page_idx);
 	if (!skb)
 		goto mpwrq_cqe_out;
 
-- 
2.24.1

[PATCH v2 net-next 20/21] net/mlx5e: NVMEoTCP statistics

[Boris Pismenny]

From: Ben Ben-Ishay <benishay@nvidia.com>

NVMEoTCP offload statistics includes both control and data path
statistic: counters for ndo, offloaded packets/bytes, dropped packets
and resync operation.

Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: Ben Ben-Ishay <benishay@nvidia.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Yoray Zack <yorayz@mellanox.com>
---
 .../mellanox/mlx5/core/en_accel/nvmeotcp.c    | 23 +++++++++++-
 .../mlx5/core/en_accel/nvmeotcp_rxtx.c        | 16 ++++++++
 .../ethernet/mellanox/mlx5/core/en_stats.c    | 37 +++++++++++++++++++
 .../ethernet/mellanox/mlx5/core/en_stats.h    | 24 ++++++++++++
 4 files changed, 98 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.c b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.c
index c2967cb4cb6a..80cd32942d8d 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp.c
@@ -656,6 +656,11 @@ mlx5e_nvmeotcp_queue_init(struct net_device *netdev,
 	struct mlx5_core_dev *mdev = priv->mdev;
 	struct mlx5e_nvmeotcp_queue *queue;
 	int max_wqe_sz_cap, queue_id, err;
+	struct mlx5e_rq_stats *stats;
+	u32 channel_ix;
+
+	channel_ix = mlx5e_get_channel_ix_from_io_cpu(priv, config->io_cpu);
+	stats = &priv->channel_stats[channel_ix].rq;
 
 	if (tconfig->type != TCP_DDP_NVME) {
 		err = -EOPNOTSUPP;
@@ -683,8 +688,7 @@ mlx5e_nvmeotcp_queue_init(struct net_device *netdev,
 	queue->id = queue_id;
 	queue->dgst = config->dgst;
 	queue->pda = config->cpda;
-	queue->channel_ix = mlx5e_get_channel_ix_from_io_cpu(priv,
-							     config->io_cpu);
+	queue->channel_ix = channel_ix;
 	queue->size = config->queue_size;
 	max_wqe_sz_cap  = min_t(int, MAX_DS_VALUE * MLX5_SEND_WQE_DS,
 				MLX5_CAP_GEN(mdev, max_wqe_sz_sq) << OCTWORD_SHIFT);
@@ -704,6 +708,7 @@ mlx5e_nvmeotcp_queue_init(struct net_device *netdev,
 	if (err)
 		goto destroy_rx;
 
+	stats->nvmeotcp_queue_init++;
 	write_lock_bh(&sk->sk_callback_lock);
 	tcp_ddp_set_ctx(sk, queue);
 	write_unlock_bh(&sk->sk_callback_lock);
@@ -718,6 +723,7 @@ mlx5e_nvmeotcp_queue_init(struct net_device *netdev,
 free_queue:
 	kfree(queue);
 out:
+	stats->nvmeotcp_queue_init_fail++;
 	return err;
 }
 
@@ -728,11 +734,15 @@ mlx5e_nvmeotcp_queue_teardown(struct net_device *netdev,
 	struct mlx5e_priv *priv = netdev_priv(netdev);
 	struct mlx5_core_dev *mdev = priv->mdev;
 	struct mlx5e_nvmeotcp_queue *queue;
+	struct mlx5e_rq_stats *stats;
 
 	queue = container_of(tcp_ddp_get_ctx(sk), struct mlx5e_nvmeotcp_queue, tcp_ddp_ctx);
 
 	napi_synchronize(&priv->channels.c[queue->channel_ix]->napi);
 
+	stats = &priv->channel_stats[queue->channel_ix].rq;
+	stats->nvmeotcp_queue_teardown++;
+
 	WARN_ON(refcount_read(&queue->ref_count) != 1);
 	if (queue->zerocopy | queue->crc_rx)
 		mlx5e_nvmeotcp_destroy_rx(queue, mdev, queue->zerocopy);
@@ -754,6 +764,7 @@ mlx5e_nvmeotcp_ddp_setup(struct net_device *netdev,
 	struct mlx5e_priv *priv = netdev_priv(netdev);
 	struct scatterlist *sg = ddp->sg_table.sgl;
 	struct mlx5e_nvmeotcp_queue *queue;
+	struct mlx5e_rq_stats *stats;
 	struct mlx5_core_dev *mdev;
 	int i, size = 0, count = 0;
 
@@ -775,6 +786,11 @@ mlx5e_nvmeotcp_ddp_setup(struct net_device *netdev,
 	queue->ccid_table[ddp->command_id].ccid_gen++;
 	queue->ccid_table[ddp->command_id].sgl_length = count;
 
+	stats = &priv->channel_stats[queue->channel_ix].rq;
+	stats->nvmeotcp_ddp_setup++;
+	if (unlikely(mlx5e_nvmeotcp_post_klm_wqe(queue, KLM_UMR, ddp->command_id, count)))
+		stats->nvmeotcp_ddp_setup_fail++;
+
 	return 0;
 }
 
@@ -815,6 +831,7 @@ mlx5e_nvmeotcp_ddp_teardown(struct net_device *netdev,
 	struct mlx5e_nvmeotcp_queue *queue;
 	struct mlx5e_priv *priv = netdev_priv(netdev);
 	struct nvmeotcp_queue_entry *q_entry;
+	struct mlx5e_rq_stats *stats;
 
 	queue = container_of(tcp_ddp_get_ctx(sk), struct mlx5e_nvmeotcp_queue, tcp_ddp_ctx);
 	q_entry  = &queue->ccid_table[ddp->command_id];
@@ -824,6 +841,8 @@ mlx5e_nvmeotcp_ddp_teardown(struct net_device *netdev,
 	q_entry->queue = queue;
 
 	mlx5e_nvmeotcp_post_klm_wqe(queue, KLM_UMR, ddp->command_id, 0);
+	stats = &priv->channel_stats[queue->channel_ix].rq;
+	stats->nvmeotcp_ddp_teardown++;
 
 	return 0;
 }
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp_rxtx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp_rxtx.c
index f446b5d56d64..e1558dfc0f3d 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp_rxtx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp_rxtx.c
@@ -10,12 +10,16 @@ static void nvmeotcp_update_resync(struct mlx5e_nvmeotcp_queue *queue,
 				   struct mlx5e_cqe128 *cqe128)
 {
 	const struct tcp_ddp_ulp_ops *ulp_ops;
+	struct mlx5e_rq_stats *stats;
 	u32 seq;
 
 	seq = be32_to_cpu(cqe128->resync_tcp_sn);
 	ulp_ops = inet_csk(queue->sk)->icsk_ulp_ddp_ops;
 	if (ulp_ops && ulp_ops->resync_request)
 		ulp_ops->resync_request(queue->sk, seq, TCP_DDP_RESYNC_REQ);
+
+	stats = queue->priv->channels.c[queue->channel_ix]->rq.stats;
+	stats->nvmeotcp_resync++;
 }
 
 static void mlx5e_nvmeotcp_advance_sgl_iter(struct mlx5e_nvmeotcp_queue *queue)
@@ -50,10 +54,13 @@ mlx5_nvmeotcp_add_tail_nonlinear(struct mlx5e_nvmeotcp_queue *queue,
 				 int org_nr_frags, int frag_index)
 {
 	struct mlx5e_priv *priv = queue->priv;
+	struct mlx5e_rq_stats *stats;
 
 	while (org_nr_frags != frag_index) {
 		if (skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS) {
 			dev_kfree_skb_any(skb);
+			stats = priv->channels.c[queue->channel_ix]->rq.stats;
+			stats->nvmeotcp_drop++;
 			return NULL;
 		}
 		skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
@@ -72,9 +79,12 @@ mlx5_nvmeotcp_add_tail(struct mlx5e_nvmeotcp_queue *queue, struct sk_buff *skb,
 		       int offset, int len)
 {
 	struct mlx5e_priv *priv = queue->priv;
+	struct mlx5e_rq_stats *stats;
 
 	if (skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS) {
 		dev_kfree_skb_any(skb);
+		stats = priv->channels.c[queue->channel_ix]->rq.stats;
+		stats->nvmeotcp_drop++;
 		return NULL;
 	}
 	skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
@@ -135,6 +145,7 @@ mlx5e_nvmeotcp_handle_rx_skb(struct net_device *netdev, struct sk_buff *skb,
 	skb_frag_t org_frags[MAX_SKB_FRAGS];
 	struct mlx5e_nvmeotcp_queue *queue;
 	struct nvmeotcp_queue_entry *nqe;
+	struct mlx5e_rq_stats *stats;
 	int org_nr_frags, frag_index;
 	struct mlx5e_cqe128 *cqe128;
 	u32 queue_id;
@@ -167,6 +178,8 @@ mlx5e_nvmeotcp_handle_rx_skb(struct net_device *netdev, struct sk_buff *skb,
 		return skb;
 	}
 
+	stats = priv->channels.c[queue->channel_ix]->rq.stats;
+
 	/* cc ddp from cqe */
 	ccid = be16_to_cpu(cqe128->ccid);
 	ccoff = be32_to_cpu(cqe128->ccoff);
@@ -209,6 +222,7 @@ mlx5e_nvmeotcp_handle_rx_skb(struct net_device *netdev, struct sk_buff *skb,
 	while (to_copy < cclen) {
 		if (skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS) {
 			dev_kfree_skb_any(skb);
+			stats->nvmeotcp_drop++;
 			mlx5e_nvmeotcp_put_queue(queue);
 			return NULL;
 		}
@@ -238,6 +252,8 @@ mlx5e_nvmeotcp_handle_rx_skb(struct net_device *netdev, struct sk_buff *skb,
 							       frag_index);
 	}
 
+	stats->nvmeotcp_offload_packets++;
+	stats->nvmeotcp_offload_bytes += cclen;
 	mlx5e_nvmeotcp_put_queue(queue);
 	return skb;
 }
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_stats.c b/drivers/net/ethernet/mellanox/mlx5/core/en_stats.c
index 2cf2042b37c7..ca7d2cb5099f 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_stats.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_stats.c
@@ -34,6 +34,7 @@
 #include "en.h"
 #include "en_accel/tls.h"
 #include "en_accel/en_accel.h"
+#include "en_accel/nvmeotcp.h"
 
 static unsigned int stats_grps_num(struct mlx5e_priv *priv)
 {
@@ -189,6 +190,18 @@ static const struct counter_desc sw_stats_desc[] = {
 	{ MLX5E_DECLARE_STAT(struct mlx5e_sw_stats, rx_tls_resync_res_ok) },
 	{ MLX5E_DECLARE_STAT(struct mlx5e_sw_stats, rx_tls_resync_res_skip) },
 	{ MLX5E_DECLARE_STAT(struct mlx5e_sw_stats, rx_tls_err) },
+#endif
+#ifdef CONFIG_MLX5_EN_NVMEOTCP
+	{ MLX5E_DECLARE_STAT(struct mlx5e_sw_stats, rx_nvmeotcp_queue_init) },
+	{ MLX5E_DECLARE_STAT(struct mlx5e_sw_stats, rx_nvmeotcp_queue_init_fail) },
+	{ MLX5E_DECLARE_STAT(struct mlx5e_sw_stats, rx_nvmeotcp_queue_teardown) },
+	{ MLX5E_DECLARE_STAT(struct mlx5e_sw_stats, rx_nvmeotcp_ddp_setup) },
+	{ MLX5E_DECLARE_STAT(struct mlx5e_sw_stats, rx_nvmeotcp_ddp_setup_fail) },
+	{ MLX5E_DECLARE_STAT(struct mlx5e_sw_stats, rx_nvmeotcp_ddp_teardown) },
+	{ MLX5E_DECLARE_STAT(struct mlx5e_sw_stats, rx_nvmeotcp_drop) },
+	{ MLX5E_DECLARE_STAT(struct mlx5e_sw_stats, rx_nvmeotcp_resync) },
+	{ MLX5E_DECLARE_STAT(struct mlx5e_sw_stats, rx_nvmeotcp_offload_packets) },
+	{ MLX5E_DECLARE_STAT(struct mlx5e_sw_stats, rx_nvmeotcp_offload_bytes) },
 #endif
 	{ MLX5E_DECLARE_STAT(struct mlx5e_sw_stats, ch_events) },
 	{ MLX5E_DECLARE_STAT(struct mlx5e_sw_stats, ch_poll) },
@@ -352,6 +365,18 @@ static void mlx5e_stats_grp_sw_update_stats_rq_stats(struct mlx5e_sw_stats *s,
 	s->rx_tls_resync_res_skip     += rq_stats->tls_resync_res_skip;
 	s->rx_tls_err                 += rq_stats->tls_err;
 #endif
+#ifdef CONFIG_MLX5_EN_NVMEOTCP
+	s->rx_nvmeotcp_queue_init      += rq_stats->nvmeotcp_queue_init;
+	s->rx_nvmeotcp_queue_init_fail += rq_stats->nvmeotcp_queue_init_fail;
+	s->rx_nvmeotcp_queue_teardown  += rq_stats->nvmeotcp_queue_teardown;
+	s->rx_nvmeotcp_ddp_setup       += rq_stats->nvmeotcp_ddp_setup;
+	s->rx_nvmeotcp_ddp_setup_fail  += rq_stats->nvmeotcp_ddp_setup_fail;
+	s->rx_nvmeotcp_ddp_teardown    += rq_stats->nvmeotcp_ddp_teardown;
+	s->rx_nvmeotcp_drop            += rq_stats->nvmeotcp_drop;
+	s->rx_nvmeotcp_resync          += rq_stats->nvmeotcp_resync;
+	s->rx_nvmeotcp_offload_packets += rq_stats->nvmeotcp_offload_packets;
+	s->rx_nvmeotcp_offload_bytes   += rq_stats->nvmeotcp_offload_bytes;
+#endif
 }
 
 static void mlx5e_stats_grp_sw_update_stats_ch_stats(struct mlx5e_sw_stats *s,
@@ -1612,6 +1637,18 @@ static const struct counter_desc rq_stats_desc[] = {
 	{ MLX5E_DECLARE_RX_STAT(struct mlx5e_rq_stats, tls_resync_res_skip) },
 	{ MLX5E_DECLARE_RX_STAT(struct mlx5e_rq_stats, tls_err) },
 #endif
+#ifdef CONFIG_MLX5_EN_NVMEOTCP
+	{ MLX5E_DECLARE_RX_STAT(struct mlx5e_rq_stats, nvmeotcp_queue_init) },
+	{ MLX5E_DECLARE_RX_STAT(struct mlx5e_rq_stats, nvmeotcp_queue_init_fail) },
+	{ MLX5E_DECLARE_RX_STAT(struct mlx5e_rq_stats, nvmeotcp_queue_teardown) },
+	{ MLX5E_DECLARE_RX_STAT(struct mlx5e_rq_stats, nvmeotcp_ddp_setup) },
+	{ MLX5E_DECLARE_RX_STAT(struct mlx5e_rq_stats, nvmeotcp_ddp_setup_fail) },
+	{ MLX5E_DECLARE_RX_STAT(struct mlx5e_rq_stats, nvmeotcp_ddp_teardown) },
+	{ MLX5E_DECLARE_RX_STAT(struct mlx5e_rq_stats, nvmeotcp_drop) },
+	{ MLX5E_DECLARE_RX_STAT(struct mlx5e_rq_stats, nvmeotcp_resync) },
+	{ MLX5E_DECLARE_RX_STAT(struct mlx5e_rq_stats, nvmeotcp_offload_packets) },
+	{ MLX5E_DECLARE_RX_STAT(struct mlx5e_rq_stats, nvmeotcp_offload_bytes) },
+#endif
 };
 
 static const struct counter_desc sq_stats_desc[] = {
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_stats.h b/drivers/net/ethernet/mellanox/mlx5/core/en_stats.h
index e41fc11f2ce7..a5cf8ec4295b 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_stats.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_stats.h
@@ -179,6 +179,18 @@ struct mlx5e_sw_stats {
 	u64 rx_congst_umr;
 	u64 rx_arfs_err;
 	u64 rx_recover;
+#ifdef CONFIG_MLX5_EN_NVMEOTCP
+	u64 rx_nvmeotcp_queue_init;
+	u64 rx_nvmeotcp_queue_init_fail;
+	u64 rx_nvmeotcp_queue_teardown;
+	u64 rx_nvmeotcp_ddp_setup;
+	u64 rx_nvmeotcp_ddp_setup_fail;
+	u64 rx_nvmeotcp_ddp_teardown;
+	u64 rx_nvmeotcp_drop;
+	u64 rx_nvmeotcp_resync;
+	u64 rx_nvmeotcp_offload_packets;
+	u64 rx_nvmeotcp_offload_bytes;
+#endif
 	u64 ch_events;
 	u64 ch_poll;
 	u64 ch_arm;
@@ -342,6 +354,18 @@ struct mlx5e_rq_stats {
 	u64 tls_resync_res_skip;
 	u64 tls_err;
 #endif
+#ifdef CONFIG_MLX5_EN_NVMEOTCP
+	u64 nvmeotcp_queue_init;
+	u64 nvmeotcp_queue_init_fail;
+	u64 nvmeotcp_queue_teardown;
+	u64 nvmeotcp_ddp_setup;
+	u64 nvmeotcp_ddp_setup_fail;
+	u64 nvmeotcp_ddp_teardown;
+	u64 nvmeotcp_drop;
+	u64 nvmeotcp_resync;
+	u64 nvmeotcp_offload_packets;
+	u64 nvmeotcp_offload_bytes;
+#endif
 };
 
 struct mlx5e_sq_stats {
-- 
2.24.1

[PATCH v2 net-next 21/21] Documentation: add TCP DDP offload documentation

[Boris Pismenny]

Add documentation to describe NIC direct data placement offload
for protocol layered over TCP. Use NVMe-TCP as an example.
---
 Documentation/networking/index.rst           |   1 +
 Documentation/networking/tcp-ddp-offload.rst | 296 +++++++++++++++++++
 2 files changed, 297 insertions(+)
 create mode 100644 Documentation/networking/tcp-ddp-offload.rst

diff --git a/Documentation/networking/index.rst b/Documentation/networking/index.rst
index b8a29997d433..99644159a0cc 100644
--- a/Documentation/networking/index.rst
+++ b/Documentation/networking/index.rst
@@ -99,6 +99,7 @@ Contents:
    sysfs-tagging
    tc-actions-env-rules
    tcp-thin
+   tcp-ddp-offload
    team
    timestamping
    tipc
diff --git a/Documentation/networking/tcp-ddp-offload.rst b/Documentation/networking/tcp-ddp-offload.rst
new file mode 100644
index 000000000000..1607e8210968
--- /dev/null
+++ b/Documentation/networking/tcp-ddp-offload.rst
@@ -0,0 +1,296 @@
+.. SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+
+=================================
+TCP direct data placement offload
+=================================
+
+Overview
+========
+
+The Linux kernel TCP direct data placement (DDP) offload infrastructure
+provides tagged request-response protocols, such as NVMe-TCP, the ability to
+place response data directly in pre-registered buffers according to header
+tags. DDP is particularly useful for data-intensive pipelined protocols whose
+responses may be reordered.
+
+For example, in NVMe-TCP numerous read requests are sent together and each
+request is tagged using the PDU header CID field. Receiving servers process
+requests as fast as possible and sometimes responses for smaller requests
+bypasses responses to larger requests, i.e., read 4KB bypasses read 1GB.
+Thereafter, clients corrleate responses to requests using PDU header CID tags.
+The processing of each response requires copying data from SKBs to read
+request destination buffers; The offload avoids this copy. The offload is
+oblivious to destination buffers which can reside either in userspace
+(O_DIRECT) or in kernel pagecache.
+
+Request TCP byte-stream:
+
+.. parsed-literal::
+
+ +---------------+-------+---------------+-------+---------------+-------+
+ | PDU hdr CID=1 | Req 1 | PDU hdr CID=2 | Req 2 | PDU hdr CID=3 | Req 3 |
+ +---------------+-------+---------------+-------+---------------+-------+
+
+Response TCP byte-stream:
+
+.. parsed-literal::
+
+ +---------------+--------+---------------+--------+---------------+--------+
+ | PDU hdr CID=2 | Resp 2 | PDU hdr CID=3 | Resp 3 | PDU hdr CID=1 | Resp 1 |
+ +---------------+--------+---------------+--------+---------------+--------+
+
+Offloading requires no new SKB bits. Instead, the driver builds SKB page
+fragments that point destination buffers. Consequently, SKBs represent the
+original data on the wire, which enables *transparent* inter-operation with the
+network stack.  To avoid copies between SKBs and destination buffers, the
+layer-5 protocol (L5P) will check ``if (src == dst)`` for SKB page fragments,
+success indicates that data is already placed there by NIC hardware and copy
+should be skipped.
+
+Offloading does require NIC hardware to track L5P procotol framing, similarly
+to RX TLS offload (see documentation at
+:ref:`Documentation/networking/tls-offload.rst <tls_offload>`).  NIC hardware
+will parse PDU headers extract fields such as operation type, length, ,tag
+identifier, etc. and offload only segments that correspond to tags registered
+with the NIC, see the :ref:`buf_reg` section.
+
+Device configuration
+====================
+
+During driver initialization the device sets the ``NETIF_F_HW_TCP_DDP`` and
+feature and installs its
+:c:type:`struct tcp_ddp_ops <tcp_ddp_ops>`
+pointer in the :c:member:`tcp_ddp_ops` member of the
+:c:type:`struct net_device <net_device>`.
+
+Later, after the L5P completes its handshake offload is installed on the socket.
+If offload installation fails, then the connection is handled by software as if
+offload was not attempted. Offload installation should configure 
+
+To request offload for a socket `sk`, the L5P calls :c:member:`tcp_ddp_sk_add`:
+
+.. code-block:: c
+
+ int (*tcp_ddp_sk_add)(struct net_device *netdev,
+ 		      struct sock *sk,
+ 		      struct tcp_ddp_config *config);
+
+The function return 0 for success. In case of failure, L5P software should
+fallback to normal non-offloaded operation.  The `config` parameter indicates
+the L5P type and any metadata relevant for that protocol. For example, in
+NVMe-TCP the following config is used:
+
+.. code-block:: c
+
+ /**
+  * struct nvme_tcp_ddp_config - nvme tcp ddp configuration for an IO queue
+  *
+  * @pfv:        pdu version (e.g., NVME_TCP_PFV_1_0)
+  * @cpda:       controller pdu data alignmend (dwords, 0's based)
+  * @dgst:       digest types enabled.
+  *              The netdev will offload crc if ddp_crc is supported.
+  * @queue_size: number of nvme-tcp IO queue elements
+  * @queue_id:   queue identifier
+  * @cpu_io:     cpu core running the IO thread for this queue
+  */
+ struct nvme_tcp_ddp_config {
+ 	struct tcp_ddp_config   cfg;
+ 
+ 	u16			pfv;
+ 	u8			cpda;
+ 	u8			dgst;
+ 	int			queue_size;
+ 	int			queue_id;
+ 	int			io_cpu;
+ };
+
+When offload is not needed anymore, e.g., the socket is being released, the L5P
+calls :c:member:`tcp_ddp_sk_del` to release device contexts:
+
+.. code-block:: c
+
+ void (*tcp_ddp_sk_del)(struct net_device *netdev,
+  		        struct sock *sk);
+
+Normal operation
+================
+
+At the very least, the device maintains the following state for each connection:
+
+ * 5-tuple
+ * expected TCP sequence number
+ * mapping between tags and corresponding buffers
+ * current offset within PDU, PDU length, current PDU tag
+
+NICs should not assume any correleation between PDUs and TCP packets.  Assuming
+that TCP packets arrive in-order, offload will place PDU payload directly
+inside corresponding registered buffers. No packets are to be delayed by NIC
+offload. If offload is not possible, than the packet is to be passed as-is to
+software. To perform offload on incoming packets without buffering packets in
+the NIC, the NIC stores some inter-packet state, such as partial PDU headers.
+
+RX data-path
+------------
+
+After the device validates TCP checksums, it can perform DDP offload.  The
+packet is steered to the DDP offload context according to the 5-tuple.
+Thereafter, the expected TCP sequence number is checked against the packet's
+TCP sequence number. If there's a match, then offload is performed: PDU payload
+is DMA written to corresponding destination buffer according to the PDU header
+tag.  The data should be DMAed only once, and the NIC receive ring will only
+store the remaining TCP and PDU headers.
+
+We remark that a single TCP packet may have numerous PDUs embedded inside. NICs
+can choose to offload one or more of these PDUs according to various
+trade-offs. Possibly, offloading such small PDUs is of little value, and it is
+better to leave it to software.
+
+Upon receiving a DDP offloaded packet, the driver reconstructs the original SKB
+using page frags, while pointing to the destination buffers whenever possible.
+This method enables seemless integration with the network stack, which can
+inspect and modify packet fields transperently to the offload.
+
+.. _buf_reg:
+
+Destination buffer registration
+-------------------------------
+
+To register the mapping betwteen tags and destination buffers for a socket
+`sk`, the L5P calls :c:member:`tcp_ddp_setup` of :c:type:`struct tcp_ddp_ops
+<tcp_ddp_ops>`:
+
+.. code-block:: c
+  
+ int (*tcp_ddp_setup)(struct net_device *netdev,
+ 		     struct sock *sk,
+ 		     struct tcp_ddp_io *io);
+
+
+The `io` provides the buffer via scatter-gather list (`sg_table`) and
+corresponding tag (`command_id`):
+
+.. code-block:: c
+ /**
+  * struct tcp_ddp_io - tcp ddp configuration for an IO request.
+  *
+  * @command_id:  identifier on the wire associated with these buffers
+  * @nents:       number of entries in the sg_table
+  * @sg_table:    describing the buffers for this IO request
+  * @first_sgl:   first SGL in sg_table
+  */
+ struct tcp_ddp_io {
+ 	u32			command_id;
+ 	int			nents;
+ 	struct sg_table		sg_table;
+ 	struct scatterlist	first_sgl[SG_CHUNK_SIZE];
+ };
+
+After the buffers have been consumed by the L5P, to release the NIC mapping of
+buffers the L5P calls :c:member:`tcp_ddp_teardown` of :c:type:`struct
+tcp_ddp_ops <tcp_ddp_ops>`: 
+
+.. code-block:: c
+  
+ int (*tcp_ddp_teardown)(struct net_device *netdev,
+ 			struct sock *sk,
+ 			struct tcp_ddp_io *io,
+ 			void *ddp_ctx);
+
+`tcp_ddp_teardown` receives the same `io` context and an additional opaque
+`ddp_ctx` that is used for asynchronous teardown, see the :ref:`async_release`
+section.
+
+.. _async_release:
+
+Asynchronous teardown
+---------------------
+
+To teardown the association between tags and buffers and allow tag reuse NIC HW
+is called by the NIC driver during `tcp_ddp_teardown`. This operation may be
+performed either synchronously or asynchronously. In asynchronous teardown,
+`tcp_ddp_teardown` returns immediately without unmapping NIC HW buffers. Later,
+when the unmapping completes by NIC HW, the NIC driver will call up to L5P
+using :c:member:`ddp_teardown_done` of :c:type:`struct tcp_ddp_ulp_ops`:
+
+.. code-block:: c
+
+ void (*ddp_teardown_done)(void *ddp_ctx);
+
+The `ddp_ctx` parameter passed in `ddp_teardown_done` is the same on provided
+in `tcp_ddp_teardown` and it is used to carry some context about the buffers
+and tags that are released.
+
+Resync handling
+===============
+
+In presence of packet drops or network packet reordering, the device may lose
+synchronization between the TCP stream and the L5P framing, and require a
+resync with the kernel's TCP stack. When the device is out of sync, no offload
+takes place, and packets are passed as-is to software. (resync is very similar
+to TLS offload (see documentation at
+:ref:`Documentation/networking/tls-offload.rst <tls_offload>`)
+
+If only packets with L5P data are lost or reordered, then resynchronization may
+be avoided by NIC HW that keeps tracking PDU headers. If, however, PDU headers
+are reordered, then resynchronization is necessary.
+
+To resynchronize hardware during traffic, we use a handshake between hardware
+and software. The NIC HW searches for a sequence of bytes that identifies L5P
+headers (i.e., magic pattern).  For example, in NVMe-TCP, the PDU operation
+type can be used for this purpose.  Using the PDU header length field, the NIC
+HW will continue to find and match magic patterns in subsequent PDU headers. If
+the pattern is missing in an expected position, then searching for the pattern
+starts anew.
+
+The NIC will not resume offload when the magic pattern is first identified.
+Instead, it will request L5P software to confirm that indeed this is a PDU
+header. To request confirmation the NIC driver calls up to L5P using
+:c:member:`*resync_request` of :c:type:`struct tcp_ddp_ulp_ops`:
+
+.. code-block:: c
+
+  bool (*resync_request)(struct sock *sk, u32 seq, u32 flags);
+
+The `seq` field contains the TCP sequence of the last byte in the PDU header.
+L5P software will respond to this request after observing the packet containing
+TCP sequence `seq` in-order. If the PDU header is indeed there, then L5P
+software calls the NIC driver using the :c:member:`tcp_ddp_resync` function of
+the :c:type:`struct tcp_ddp_ops <tcp_ddp_ops>` inside the :c:type:`struct
+net_device <net_device>` while passing the same `seq` to confirm it is a PDU
+header.
+
+.. code-block:: c
+
+ void (*tcp_ddp_resync)(struct net_device *netdev,
+ 		       struct sock *sk, u32 seq);
+
+Statistics
+==========
+
+Per L5P protocol, the following NIC driver must report statistics for the above
+netdevice operations and packets processed by offload. For example, NVMe-TCP
+offload reports:
+
+ * ``rx_nvmeotcp_queue_init`` - number of NVMe-TCP offload contexts created.
+ * ``rx_nvmeotcp_queue_teardown`` - number of NVMe-TCP offload contexts
+   destroyed.
+ * ``rx_nvmeotcp_ddp_setup`` - number of DDP buffers mapped.
+ * ``rx_nvmeotcp_ddp_setup_fail`` - number of DDP buffers mapping that failed.
+ * ``rx_nvmeotcp_ddp_teardown`` - number of DDP buffers unmapped.
+ * ``rx_nvmeotcp_drop`` - number of packets dropped in the driver due to fatal
+   errors.
+ * ``rx_nvmeotcp_resync`` - number of packets with resync requests.
+ * ``rx_nvmeotcp_offload_packets`` - number of packets that used offload.
+ * ``rx_nvmeotcp_offload_bytes`` - number of bytes placed in DDP buffers.
+
+NIC requirements
+================
+
+NIC hardware should meet the following requirements to provide this offload:
+
+ * Offload must never buffer TCP packets.
+ * Offload must never modify TCP packet headers.
+ * Offload must never reorder TCP packets within a flow.
+ * Offload must never drop TCP packets.
+ * Offload must not depend on any TCP fields beyond the
+   5-tuple and TCP sequence number.
-- 
2.24.1

Re: [PATCH v2 net-next 02/21] net: Introduce direct data placement tcp offload

[Eric Dumazet]

On Thu, Jan 14, 2021 at 4:10 PM Boris Pismenny <borisp@mellanox.com> wrote:
>
> This commit introduces direct data placement offload for TCP.
> This capability is accompanied by new net_device operations that
> configure hardware contexts. There is a context per socket, and a context per DDP
> opreation. Additionally, a resynchronization routine is used to assist
> hardware handle TCP OOO, and continue the offload.
> Furthermore, we let the offloading driver advertise what is the max hw
> sectors/segments.
>
> Using this interface, the NIC hardware will scatter TCP payload directly
> to the BIO pages according to the command_id.
> To maintain the correctness of the network stack, the driver is expected
> to construct SKBs that point to the BIO pages.
>
> This, the SKB represents the data on the wire, while it is pointing
> to data that is already placed in the destination buffer.
> As a result, data from page frags should not be copied out to
> the linear part.
>
> As SKBs that use DDP are already very memory efficient, we modify
> skb_condence to avoid copying data from fragments to the linear
> part of SKBs that belong to a socket that uses DDP offload.
>
> A follow-up patch will use this interface for DDP in NVMe-TCP.
>
> Signed-off-by: Boris Pismenny <borisp@mellanox.com>
> Signed-off-by: Ben Ben-Ishay <benishay@mellanox.com>
> Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
> Signed-off-by: Yoray Zack <yorayz@mellanox.com>
> ---
>  include/linux/netdev_features.h    |   2 +
>  include/linux/netdevice.h          |   5 ++
>  include/net/inet_connection_sock.h |   4 +
>  include/net/tcp_ddp.h              | 136 +++++++++++++++++++++++++++++
>  net/Kconfig                        |   9 ++
>  net/core/skbuff.c                  |   9 +-
>  net/ethtool/common.c               |   1 +
>  7 files changed, 165 insertions(+), 1 deletion(-)
>  create mode 100644 include/net/tcp_ddp.h
>
> diff --git a/include/linux/netdev_features.h b/include/linux/netdev_features.h
> index 934de56644e7..fb35dcac03d2 100644
> --- a/include/linux/netdev_features.h
> +++ b/include/linux/netdev_features.h
> @@ -84,6 +84,7 @@ enum {
>         NETIF_F_GRO_FRAGLIST_BIT,       /* Fraglist GRO */
>
>         NETIF_F_HW_MACSEC_BIT,          /* Offload MACsec operations */
> +       NETIF_F_HW_TCP_DDP_BIT,         /* TCP direct data placement offload */
>
>         /*
>          * Add your fresh new feature above and remember to update
> @@ -157,6 +158,7 @@ enum {
>  #define NETIF_F_GRO_FRAGLIST   __NETIF_F(GRO_FRAGLIST)
>  #define NETIF_F_GSO_FRAGLIST   __NETIF_F(GSO_FRAGLIST)
>  #define NETIF_F_HW_MACSEC      __NETIF_F(HW_MACSEC)
> +#define NETIF_F_HW_TCP_DDP     __NETIF_F(HW_TCP_DDP)
>
>  /* Finds the next feature with the highest number of the range of start till 0.
>   */
> diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
> index 259be67644e3..3dd3cdf5dec3 100644
> --- a/include/linux/netdevice.h
> +++ b/include/linux/netdevice.h
> @@ -941,6 +941,7 @@ struct dev_ifalias {
>
>  struct devlink;
>  struct tlsdev_ops;
> +struct tcp_ddp_dev_ops;
>
>  struct netdev_name_node {
>         struct hlist_node hlist;
> @@ -1937,6 +1938,10 @@ struct net_device {
>         const struct tlsdev_ops *tlsdev_ops;
>  #endif
>
> +#ifdef CONFIG_TCP_DDP
> +       const struct tcp_ddp_dev_ops *tcp_ddp_ops;
> +#endif
> +
>         const struct header_ops *header_ops;
>
>         unsigned int            flags;
> diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connection_sock.h
> index 7338b3865a2a..a08b85b53aa8 100644
> --- a/include/net/inet_connection_sock.h
> +++ b/include/net/inet_connection_sock.h
> @@ -66,6 +66,8 @@ struct inet_connection_sock_af_ops {
>   * @icsk_ulp_ops          Pluggable ULP control hook
>   * @icsk_ulp_data         ULP private data
>   * @icsk_clean_acked      Clean acked data hook
> + * @icsk_ulp_ddp_ops      Pluggable ULP direct data placement control hook
> + * @icsk_ulp_ddp_data     ULP direct data placement private data
>   * @icsk_listen_portaddr_node  hash to the portaddr listener hashtable
>   * @icsk_ca_state:        Congestion control state
>   * @icsk_retransmits:     Number of unrecovered [RTO] timeouts
> @@ -94,6 +96,8 @@ struct inet_connection_sock {
>         const struct tcp_ulp_ops  *icsk_ulp_ops;
>         void __rcu                *icsk_ulp_data;
>         void (*icsk_clean_acked)(struct sock *sk, u32 acked_seq);

#ifdef CONFIG_TCP_DDP ?

> +       const struct tcp_ddp_ulp_ops  *icsk_ulp_ddp_ops;
> +       void __rcu                *icsk_ulp_ddp_data;
>         struct hlist_node         icsk_listen_portaddr_node;
>         unsigned int              (*icsk_sync_mss)(struct sock *sk, u32 pmtu);
>         __u8                      icsk_ca_state:5,
> diff --git a/include/net/tcp_ddp.h b/include/net/tcp_ddp.h
> new file mode 100644
> index 000000000000..31e5b1a16d0f
> --- /dev/null
> +++ b/include/net/tcp_ddp.h
> @@ -0,0 +1,136 @@
> +/* SPDX-License-Identifier: GPL-2.0
> + *
> + * tcp_ddp.h
> + *     Author: Boris Pismenny <borisp@mellanox.com>
> + *     Copyright (C) 2021 Mellanox Technologies.
> + */
> +#ifndef _TCP_DDP_H
> +#define _TCP_DDP_H
> +
> +#include <linux/netdevice.h>
> +#include <net/inet_connection_sock.h>
> +#include <net/sock.h>
> +
> +/* limits returned by the offload driver, zero means don't care */
> +struct tcp_ddp_limits {
> +       int      max_ddp_sgl_len;
> +};
> +
> +enum tcp_ddp_type {
> +       TCP_DDP_NVME = 1,
> +};
> +
> +/**
> + * struct tcp_ddp_config - Generic tcp ddp configuration: tcp ddp IO queue
> + * config implementations must use this as the first member.
> + * Add new instances of tcp_ddp_config below (nvme-tcp, etc.).
> + */
> +struct tcp_ddp_config {
> +       enum tcp_ddp_type    type;
> +       unsigned char        buf[];
> +};
> +
> +/**
> + * struct nvme_tcp_ddp_config - nvme tcp ddp configuration for an IO queue
> + *
> + * @pfv:        pdu version (e.g., NVME_TCP_PFV_1_0)
> + * @cpda:       controller pdu data alignmend (dwords, 0's based)
> + * @dgst:       digest types enabled.
> + *              The netdev will offload crc if ddp_crc is supported.
> + * @queue_size: number of nvme-tcp IO queue elements
> + * @queue_id:   queue identifier
> + * @cpu_io:     cpu core running the IO thread for this queue
> + */
> +struct nvme_tcp_ddp_config {
> +       struct tcp_ddp_config   cfg;
> +
> +       u16                     pfv;
> +       u8                      cpda;
> +       u8                      dgst;
> +       int                     queue_size;
> +       int                     queue_id;
> +       int                     io_cpu;
> +};
> +
> +/**
> + * struct tcp_ddp_io - tcp ddp configuration for an IO request.
> + *
> + * @command_id:  identifier on the wire associated with these buffers
> + * @nents:       number of entries in the sg_table
> + * @sg_table:    describing the buffers for this IO request
> + * @first_sgl:   first SGL in sg_table
> + */
> +struct tcp_ddp_io {
> +       u32                     command_id;
> +       int                     nents;
> +       struct sg_table         sg_table;
> +       struct scatterlist      first_sgl[SG_CHUNK_SIZE];
> +};
> +
> +/* struct tcp_ddp_dev_ops - operations used by an upper layer protocol to configure ddp offload
> + *
> + * @tcp_ddp_limits:    limit the number of scatter gather entries per IO.
> + *                     the device driver can use this to limit the resources allocated per queue.
> + * @tcp_ddp_sk_add:    add offload for the queue represennted by the socket+config pair.
> + *                     this function is used to configure either copy, crc or both offloads.
> + * @tcp_ddp_sk_del:    remove offload from the socket, and release any device related resources.
> + * @tcp_ddp_setup:     request copy offload for buffers associated with a command_id in tcp_ddp_io.
> + * @tcp_ddp_teardown:  release offload resources association between buffers and command_id in
> + *                     tcp_ddp_io.
> + * @tcp_ddp_resync:    respond to the driver's resync_request. Called only if resync is successful.
> + */
> +struct tcp_ddp_dev_ops {
> +       int (*tcp_ddp_limits)(struct net_device *netdev,
> +                             struct tcp_ddp_limits *limits);
> +       int (*tcp_ddp_sk_add)(struct net_device *netdev,
> +                             struct sock *sk,
> +                             struct tcp_ddp_config *config);
> +       void (*tcp_ddp_sk_del)(struct net_device *netdev,
> +                              struct sock *sk);
> +       int (*tcp_ddp_setup)(struct net_device *netdev,
> +                            struct sock *sk,
> +                            struct tcp_ddp_io *io);
> +       int (*tcp_ddp_teardown)(struct net_device *netdev,
> +                               struct sock *sk,
> +                               struct tcp_ddp_io *io,
> +                               void *ddp_ctx);
> +       void (*tcp_ddp_resync)(struct net_device *netdev,
> +                              struct sock *sk, u32 seq);
> +};
> +
> +#define TCP_DDP_RESYNC_REQ BIT(0)
> +
> +/**
> + * struct tcp_ddp_ulp_ops - Interface to register uppper layer Direct Data Placement (DDP) TCP offload
> + */
> +struct tcp_ddp_ulp_ops {
> +       /* NIC requests ulp to indicate if @seq is the start of a message */
> +       bool (*resync_request)(struct sock *sk, u32 seq, u32 flags);
> +       /* NIC driver informs the ulp that ddp teardown is done - used for async completions*/
> +       void (*ddp_teardown_done)(void *ddp_ctx);
> +};
> +
> +/**
> + * struct tcp_ddp_ctx - Generic tcp ddp context: device driver per queue contexts must
> + * use this as the first member.
> + */
> +struct tcp_ddp_ctx {
> +       enum tcp_ddp_type    type;
> +       unsigned char        buf[];
> +};
> +
> +static inline struct tcp_ddp_ctx *tcp_ddp_get_ctx(const struct sock *sk)
> +{
> +       struct inet_connection_sock *icsk = inet_csk(sk);
> +
> +       return (__force struct tcp_ddp_ctx *)icsk->icsk_ulp_ddp_data;
> +}
> +
> +static inline void tcp_ddp_set_ctx(struct sock *sk, void *ctx)
> +{
> +       struct inet_connection_sock *icsk = inet_csk(sk);
> +
> +       rcu_assign_pointer(icsk->icsk_ulp_ddp_data, ctx);
> +}
> +
> +#endif //_TCP_DDP_H
> diff --git a/net/Kconfig b/net/Kconfig
> index f4c32d982af6..3876861cdc90 100644
> --- a/net/Kconfig
> +++ b/net/Kconfig
> @@ -457,6 +457,15 @@ config ETHTOOL_NETLINK
>           netlink. It provides better extensibility and some new features,
>           e.g. notification messages.
>
> +config TCP_DDP
> +       bool "TCP direct data placement offload"
> +       default n
> +       help
> +         Direct Data Placement (DDP) offload for TCP enables ULP, such as
> +         NVMe-TCP/iSCSI, to request the NIC to place TCP payload data
> +         of a command response directly into kernel pages.
> +
> +
>  endif   # if NET
>
>  # Used by archs to tell that they support BPF JIT compiler plus which flavour.
> diff --git a/net/core/skbuff.c b/net/core/skbuff.c
> index f62cae3f75d8..791c1b6bc067 100644
> --- a/net/core/skbuff.c
> +++ b/net/core/skbuff.c
> @@ -69,6 +69,7 @@
>  #include <net/xfrm.h>
>  #include <net/mpls.h>
>  #include <net/mptcp.h>
> +#include <net/tcp_ddp.h>
>
>  #include <linux/uaccess.h>
>  #include <trace/events/skb.h>
> @@ -6140,9 +6141,15 @@ EXPORT_SYMBOL(pskb_extract);
>   */
>  void skb_condense(struct sk_buff *skb)
>  {
> +       bool is_ddp = false;
> +
> +#ifdef CONFIG_TCP_DDP

This looks strange to me : TCP should call this helper while skb->sk is NULL

Are you sure this is not dead code ?

> +       is_ddp = skb->sk && inet_csk(skb->sk) &&
> +                inet_csk(skb->sk)->icsk_ulp_ddp_data;
> +#endif
>         if (skb->data_len) {
>                 if (skb->data_len > skb->end - skb->tail ||
> -                   skb_cloned(skb))
> +                   skb_cloned(skb) || is_ddp)
>                         return;
>
>                 /* Nice, we can free page frag(s) right now */
> diff --git a/net/ethtool/common.c b/net/ethtool/common.c
> index 24036e3055a1..a2ff7a4a6bbf 100644
> --- a/net/ethtool/common.c
> +++ b/net/ethtool/common.c
> @@ -68,6 +68,7 @@ const char netdev_features_strings[NETDEV_FEATURE_COUNT][ETH_GSTRING_LEN] = {
>         [NETIF_F_HW_TLS_RX_BIT] =        "tls-hw-rx-offload",
>         [NETIF_F_GRO_FRAGLIST_BIT] =     "rx-gro-list",
>         [NETIF_F_HW_MACSEC_BIT] =        "macsec-hw-offload",
> +       [NETIF_F_HW_TCP_DDP_BIT] =       "tcp-ddp-offload",
>  };
>
>  const char
> --
> 2.24.1
>

Re: [PATCH v2 net-next 02/21] net: Introduce direct data placement tcp offload

[Boris Pismenny]

On 14/01/2021 17:57, Eric Dumazet wrote:
> On Thu, Jan 14, 2021 at 4:10 PM Boris Pismenny <borisp@mellanox.com> wrote:
>>
>> This commit introduces direct data placement offload for TCP.
>> This capability is accompanied by new net_device operations that
>> configure hardware contexts. There is a context per socket, and a context per DDP
>> opreation. Additionally, a resynchronization routine is used to assist
>> hardware handle TCP OOO, and continue the offload.
>> Furthermore, we let the offloading driver advertise what is the max hw
>> sectors/segments.
>>
>> Using this interface, the NIC hardware will scatter TCP payload directly
>> to the BIO pages according to the command_id.
>> To maintain the correctness of the network stack, the driver is expected
>> to construct SKBs that point to the BIO pages.
>>
>> This, the SKB represents the data on the wire, while it is pointing
>> to data that is already placed in the destination buffer.
>> As a result, data from page frags should not be copied out to
>> the linear part.
>>
>> As SKBs that use DDP are already very memory efficient, we modify
>> skb_condence to avoid copying data from fragments to the linear
>> part of SKBs that belong to a socket that uses DDP offload.
>>
>> A follow-up patch will use this interface for DDP in NVMe-TCP.
>>
>> Signed-off-by: Boris Pismenny <borisp@mellanox.com>
>> Signed-off-by: Ben Ben-Ishay <benishay@mellanox.com>
>> Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
>> Signed-off-by: Yoray Zack <yorayz@mellanox.com>
>> ---
>>  include/linux/netdev_features.h    |   2 +
>>  include/linux/netdevice.h          |   5 ++
>>  include/net/inet_connection_sock.h |   4 +
>>  include/net/tcp_ddp.h              | 136 +++++++++++++++++++++++++++++
>>  net/Kconfig                        |   9 ++
>>  net/core/skbuff.c                  |   9 +-
>>  net/ethtool/common.c               |   1 +
>>  7 files changed, 165 insertions(+), 1 deletion(-)
>>  create mode 100644 include/net/tcp_ddp.h
>>
>> diff --git a/include/linux/netdev_features.h b/include/linux/netdev_features.h
>> index 934de56644e7..fb35dcac03d2 100644
>> --- a/include/linux/netdev_features.h
>> +++ b/include/linux/netdev_features.h
>> @@ -84,6 +84,7 @@ enum {
>>         NETIF_F_GRO_FRAGLIST_BIT,       /* Fraglist GRO */
>>
>>         NETIF_F_HW_MACSEC_BIT,          /* Offload MACsec operations */
>> +       NETIF_F_HW_TCP_DDP_BIT,         /* TCP direct data placement offload */
>>
>>         /*
>>          * Add your fresh new feature above and remember to update
>> @@ -157,6 +158,7 @@ enum {
>>  #define NETIF_F_GRO_FRAGLIST   __NETIF_F(GRO_FRAGLIST)
>>  #define NETIF_F_GSO_FRAGLIST   __NETIF_F(GSO_FRAGLIST)
>>  #define NETIF_F_HW_MACSEC      __NETIF_F(HW_MACSEC)
>> +#define NETIF_F_HW_TCP_DDP     __NETIF_F(HW_TCP_DDP)
>>
>>  /* Finds the next feature with the highest number of the range of start till 0.
>>   */
>> diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
>> index 259be67644e3..3dd3cdf5dec3 100644
>> --- a/include/linux/netdevice.h
>> +++ b/include/linux/netdevice.h
>> @@ -941,6 +941,7 @@ struct dev_ifalias {
>>
>>  struct devlink;
>>  struct tlsdev_ops;
>> +struct tcp_ddp_dev_ops;
>>
>>  struct netdev_name_node {
>>         struct hlist_node hlist;
>> @@ -1937,6 +1938,10 @@ struct net_device {
>>         const struct tlsdev_ops *tlsdev_ops;
>>  #endif
>>
>> +#ifdef CONFIG_TCP_DDP
>> +       const struct tcp_ddp_dev_ops *tcp_ddp_ops;
>> +#endif
>> +
>>         const struct header_ops *header_ops;
>>
>>         unsigned int            flags;
>> diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connection_sock.h
>> index 7338b3865a2a..a08b85b53aa8 100644
>> --- a/include/net/inet_connection_sock.h
>> +++ b/include/net/inet_connection_sock.h
>> @@ -66,6 +66,8 @@ struct inet_connection_sock_af_ops {
>>   * @icsk_ulp_ops          Pluggable ULP control hook
>>   * @icsk_ulp_data         ULP private data
>>   * @icsk_clean_acked      Clean acked data hook
>> + * @icsk_ulp_ddp_ops      Pluggable ULP direct data placement control hook
>> + * @icsk_ulp_ddp_data     ULP direct data placement private data
>>   * @icsk_listen_portaddr_node  hash to the portaddr listener hashtable
>>   * @icsk_ca_state:        Congestion control state
>>   * @icsk_retransmits:     Number of unrecovered [RTO] timeouts
>> @@ -94,6 +96,8 @@ struct inet_connection_sock {
>>         const struct tcp_ulp_ops  *icsk_ulp_ops;
>>         void __rcu                *icsk_ulp_data;
>>         void (*icsk_clean_acked)(struct sock *sk, u32 acked_seq);
> 
> #ifdef CONFIG_TCP_DDP ?
> 
>> +       const struct tcp_ddp_ulp_ops  *icsk_ulp_ddp_ops;
>> +       void __rcu                *icsk_ulp_ddp_data;
>>         struct hlist_node         icsk_listen_portaddr_node;
>>         unsigned int              (*icsk_sync_mss)(struct sock *sk, u32 pmtu);
>>         __u8                      icsk_ca_state:5,
>> diff --git a/include/net/tcp_ddp.h b/include/net/tcp_ddp.h
>> new file mode 100644
>> index 000000000000..31e5b1a16d0f
>> --- /dev/null
>> +++ b/include/net/tcp_ddp.h
>> @@ -0,0 +1,136 @@
>> +/* SPDX-License-Identifier: GPL-2.0
>> + *
>> + * tcp_ddp.h
>> + *     Author: Boris Pismenny <borisp@mellanox.com>
>> + *     Copyright (C) 2021 Mellanox Technologies.
>> + */
>> +#ifndef _TCP_DDP_H
>> +#define _TCP_DDP_H
>> +
>> +#include <linux/netdevice.h>
>> +#include <net/inet_connection_sock.h>
>> +#include <net/sock.h>
>> +
>> +/* limits returned by the offload driver, zero means don't care */
>> +struct tcp_ddp_limits {
>> +       int      max_ddp_sgl_len;
>> +};
>> +
>> +enum tcp_ddp_type {
>> +       TCP_DDP_NVME = 1,
>> +};
>> +
>> +/**
>> + * struct tcp_ddp_config - Generic tcp ddp configuration: tcp ddp IO queue
>> + * config implementations must use this as the first member.
>> + * Add new instances of tcp_ddp_config below (nvme-tcp, etc.).
>> + */
>> +struct tcp_ddp_config {
>> +       enum tcp_ddp_type    type;
>> +       unsigned char        buf[];
>> +};
>> +
>> +/**
>> + * struct nvme_tcp_ddp_config - nvme tcp ddp configuration for an IO queue
>> + *
>> + * @pfv:        pdu version (e.g., NVME_TCP_PFV_1_0)
>> + * @cpda:       controller pdu data alignmend (dwords, 0's based)
>> + * @dgst:       digest types enabled.
>> + *              The netdev will offload crc if ddp_crc is supported.
>> + * @queue_size: number of nvme-tcp IO queue elements
>> + * @queue_id:   queue identifier
>> + * @cpu_io:     cpu core running the IO thread for this queue
>> + */
>> +struct nvme_tcp_ddp_config {
>> +       struct tcp_ddp_config   cfg;
>> +
>> +       u16                     pfv;
>> +       u8                      cpda;
>> +       u8                      dgst;
>> +       int                     queue_size;
>> +       int                     queue_id;
>> +       int                     io_cpu;
>> +};
>> +
>> +/**
>> + * struct tcp_ddp_io - tcp ddp configuration for an IO request.
>> + *
>> + * @command_id:  identifier on the wire associated with these buffers
>> + * @nents:       number of entries in the sg_table
>> + * @sg_table:    describing the buffers for this IO request
>> + * @first_sgl:   first SGL in sg_table
>> + */
>> +struct tcp_ddp_io {
>> +       u32                     command_id;
>> +       int                     nents;
>> +       struct sg_table         sg_table;
>> +       struct scatterlist      first_sgl[SG_CHUNK_SIZE];
>> +};
>> +
>> +/* struct tcp_ddp_dev_ops - operations used by an upper layer protocol to configure ddp offload
>> + *
>> + * @tcp_ddp_limits:    limit the number of scatter gather entries per IO.
>> + *                     the device driver can use this to limit the resources allocated per queue.
>> + * @tcp_ddp_sk_add:    add offload for the queue represennted by the socket+config pair.
>> + *                     this function is used to configure either copy, crc or both offloads.
>> + * @tcp_ddp_sk_del:    remove offload from the socket, and release any device related resources.
>> + * @tcp_ddp_setup:     request copy offload for buffers associated with a command_id in tcp_ddp_io.
>> + * @tcp_ddp_teardown:  release offload resources association between buffers and command_id in
>> + *                     tcp_ddp_io.
>> + * @tcp_ddp_resync:    respond to the driver's resync_request. Called only if resync is successful.
>> + */
>> +struct tcp_ddp_dev_ops {
>> +       int (*tcp_ddp_limits)(struct net_device *netdev,
>> +                             struct tcp_ddp_limits *limits);
>> +       int (*tcp_ddp_sk_add)(struct net_device *netdev,
>> +                             struct sock *sk,
>> +                             struct tcp_ddp_config *config);
>> +       void (*tcp_ddp_sk_del)(struct net_device *netdev,
>> +                              struct sock *sk);
>> +       int (*tcp_ddp_setup)(struct net_device *netdev,
>> +                            struct sock *sk,
>> +                            struct tcp_ddp_io *io);
>> +       int (*tcp_ddp_teardown)(struct net_device *netdev,
>> +                               struct sock *sk,
>> +                               struct tcp_ddp_io *io,
>> +                               void *ddp_ctx);
>> +       void (*tcp_ddp_resync)(struct net_device *netdev,
>> +                              struct sock *sk, u32 seq);
>> +};
>> +
>> +#define TCP_DDP_RESYNC_REQ BIT(0)
>> +
>> +/**
>> + * struct tcp_ddp_ulp_ops - Interface to register uppper layer Direct Data Placement (DDP) TCP offload
>> + */
>> +struct tcp_ddp_ulp_ops {
>> +       /* NIC requests ulp to indicate if @seq is the start of a message */
>> +       bool (*resync_request)(struct sock *sk, u32 seq, u32 flags);
>> +       /* NIC driver informs the ulp that ddp teardown is done - used for async completions*/
>> +       void (*ddp_teardown_done)(void *ddp_ctx);
>> +};
>> +
>> +/**
>> + * struct tcp_ddp_ctx - Generic tcp ddp context: device driver per queue contexts must
>> + * use this as the first member.
>> + */
>> +struct tcp_ddp_ctx {
>> +       enum tcp_ddp_type    type;
>> +       unsigned char        buf[];
>> +};
>> +
>> +static inline struct tcp_ddp_ctx *tcp_ddp_get_ctx(const struct sock *sk)
>> +{
>> +       struct inet_connection_sock *icsk = inet_csk(sk);
>> +
>> +       return (__force struct tcp_ddp_ctx *)icsk->icsk_ulp_ddp_data;
>> +}
>> +
>> +static inline void tcp_ddp_set_ctx(struct sock *sk, void *ctx)
>> +{
>> +       struct inet_connection_sock *icsk = inet_csk(sk);
>> +
>> +       rcu_assign_pointer(icsk->icsk_ulp_ddp_data, ctx);
>> +}
>> +
>> +#endif //_TCP_DDP_H
>> diff --git a/net/Kconfig b/net/Kconfig
>> index f4c32d982af6..3876861cdc90 100644
>> --- a/net/Kconfig
>> +++ b/net/Kconfig
>> @@ -457,6 +457,15 @@ config ETHTOOL_NETLINK
>>           netlink. It provides better extensibility and some new features,
>>           e.g. notification messages.
>>
>> +config TCP_DDP
>> +       bool "TCP direct data placement offload"
>> +       default n
>> +       help
>> +         Direct Data Placement (DDP) offload for TCP enables ULP, such as
>> +         NVMe-TCP/iSCSI, to request the NIC to place TCP payload data
>> +         of a command response directly into kernel pages.
>> +
>> +
>>  endif   # if NET
>>
>>  # Used by archs to tell that they support BPF JIT compiler plus which flavour.
>> diff --git a/net/core/skbuff.c b/net/core/skbuff.c
>> index f62cae3f75d8..791c1b6bc067 100644
>> --- a/net/core/skbuff.c
>> +++ b/net/core/skbuff.c
>> @@ -69,6 +69,7 @@
>>  #include <net/xfrm.h>
>>  #include <net/mpls.h>
>>  #include <net/mptcp.h>
>> +#include <net/tcp_ddp.h>
>>
>>  #include <linux/uaccess.h>
>>  #include <trace/events/skb.h>
>> @@ -6140,9 +6141,15 @@ EXPORT_SYMBOL(pskb_extract);
>>   */
>>  void skb_condense(struct sk_buff *skb)
>>  {
>> +       bool is_ddp = false;
>> +
>> +#ifdef CONFIG_TCP_DDP
> 
> This looks strange to me : TCP should call this helper while skb->sk is NULL
> 
> Are you sure this is not dead code ?
> 

Will verify again on Sunday. AFAICT, early demux sets skb->sk before this code
is called. Just to clarify, the purpose of this code is to avoid skb condensing
data that is already placed into destination buffers.

>> +       is_ddp = skb->sk && inet_csk(skb->sk) &&
>> +                inet_csk(skb->sk)->icsk_ulp_ddp_data;
>> +#endif
>>         if (skb->data_len) {
>>                 if (skb->data_len > skb->end - skb->tail ||
>> -                   skb_cloned(skb))
>> +                   skb_cloned(skb) || is_ddp)
>>                         return;
>>
>>                 /* Nice, we can free page frag(s) right now */
>> diff --git a/net/ethtool/common.c b/net/ethtool/common.c
>> index 24036e3055a1..a2ff7a4a6bbf 100644
>> --- a/net/ethtool/common.c
>> +++ b/net/ethtool/common.c
>> @@ -68,6 +68,7 @@ const char netdev_features_strings[NETDEV_FEATURE_COUNT][ETH_GSTRING_LEN] = {
>>         [NETIF_F_HW_TLS_RX_BIT] =        "tls-hw-rx-offload",
>>         [NETIF_F_GRO_FRAGLIST_BIT] =     "rx-gro-list",
>>         [NETIF_F_HW_MACSEC_BIT] =        "macsec-hw-offload",
>> +       [NETIF_F_HW_TCP_DDP_BIT] =       "tcp-ddp-offload",
>>  };
>>
>>  const char
>> --
>> 2.24.1
>>

Re: [PATCH v2 net-next 02/21] net: Introduce direct data placement tcp offload

[Eric Dumazet]

On Thu, Jan 14, 2021 at 9:19 PM Boris Pismenny <borispismenny@gmail.com> wrote:
>
>
>
> On 14/01/2021 17:57, Eric Dumazet wrote:
> > On Thu, Jan 14, 2021 at 4:10 PM Boris Pismenny <borisp@mellanox.com> wrote:
> >>
> >> This commit introduces direct data placement offload for TCP.
> >> This capability is accompanied by new net_device operations that
> >> configure hardware contexts. There is a context per socket, and a context per DDP
> >> opreation. Additionally, a resynchronization routine is used to assist
> >> hardware handle TCP OOO, and continue the offload.
> >> Furthermore, we let the offloading driver advertise what is the max hw
> >> sectors/segments.
> >>
> >> Using this interface, the NIC hardware will scatter TCP payload directly
> >> to the BIO pages according to the command_id.
> >> To maintain the correctness of the network stack, the driver is expected
> >> to construct SKBs that point to the BIO pages.
> >>
> >> This, the SKB represents the data on the wire, while it is pointing
> >> to data that is already placed in the destination buffer.
> >> As a result, data from page frags should not be copied out to
> >> the linear part.
> >>
> >> As SKBs that use DDP are already very memory efficient, we modify
> >> skb_condence to avoid copying data from fragments to the linear
> >> part of SKBs that belong to a socket that uses DDP offload.
> >>
> >> A follow-up patch will use this interface for DDP in NVMe-TCP.
> >>
> >> Signed-off-by: Boris Pismenny <borisp@mellanox.com>
> >> Signed-off-by: Ben Ben-Ishay <benishay@mellanox.com>
> >> Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
> >> Signed-off-by: Yoray Zack <yorayz@mellanox.com>
> >> ---
> >>  include/linux/netdev_features.h    |   2 +
> >>  include/linux/netdevice.h          |   5 ++
> >>  include/net/inet_connection_sock.h |   4 +
> >>  include/net/tcp_ddp.h              | 136 +++++++++++++++++++++++++++++
> >>  net/Kconfig                        |   9 ++
> >>  net/core/skbuff.c                  |   9 +-
> >>  net/ethtool/common.c               |   1 +
> >>  7 files changed, 165 insertions(+), 1 deletion(-)
> >>  create mode 100644 include/net/tcp_ddp.h
> >>
> >> diff --git a/include/linux/netdev_features.h b/include/linux/netdev_features.h
> >> index 934de56644e7..fb35dcac03d2 100644
> >> --- a/include/linux/netdev_features.h
> >> +++ b/include/linux/netdev_features.h
> >> @@ -84,6 +84,7 @@ enum {
> >>         NETIF_F_GRO_FRAGLIST_BIT,       /* Fraglist GRO */
> >>
> >>         NETIF_F_HW_MACSEC_BIT,          /* Offload MACsec operations */
> >> +       NETIF_F_HW_TCP_DDP_BIT,         /* TCP direct data placement offload */
> >>
> >>         /*
> >>          * Add your fresh new feature above and remember to update
> >> @@ -157,6 +158,7 @@ enum {
> >>  #define NETIF_F_GRO_FRAGLIST   __NETIF_F(GRO_FRAGLIST)
> >>  #define NETIF_F_GSO_FRAGLIST   __NETIF_F(GSO_FRAGLIST)
> >>  #define NETIF_F_HW_MACSEC      __NETIF_F(HW_MACSEC)
> >> +#define NETIF_F_HW_TCP_DDP     __NETIF_F(HW_TCP_DDP)
> >>
> >>  /* Finds the next feature with the highest number of the range of start till 0.
> >>   */
> >> diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
> >> index 259be67644e3..3dd3cdf5dec3 100644
> >> --- a/include/linux/netdevice.h
> >> +++ b/include/linux/netdevice.h
> >> @@ -941,6 +941,7 @@ struct dev_ifalias {
> >>
> >>  struct devlink;
> >>  struct tlsdev_ops;
> >> +struct tcp_ddp_dev_ops;
> >>
> >>  struct netdev_name_node {
> >>         struct hlist_node hlist;
> >> @@ -1937,6 +1938,10 @@ struct net_device {
> >>         const struct tlsdev_ops *tlsdev_ops;
> >>  #endif
> >>
> >> +#ifdef CONFIG_TCP_DDP
> >> +       const struct tcp_ddp_dev_ops *tcp_ddp_ops;
> >> +#endif
> >> +
> >>         const struct header_ops *header_ops;
> >>
> >>         unsigned int            flags;
> >> diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connection_sock.h
> >> index 7338b3865a2a..a08b85b53aa8 100644
> >> --- a/include/net/inet_connection_sock.h
> >> +++ b/include/net/inet_connection_sock.h
> >> @@ -66,6 +66,8 @@ struct inet_connection_sock_af_ops {
> >>   * @icsk_ulp_ops          Pluggable ULP control hook
> >>   * @icsk_ulp_data         ULP private data
> >>   * @icsk_clean_acked      Clean acked data hook
> >> + * @icsk_ulp_ddp_ops      Pluggable ULP direct data placement control hook
> >> + * @icsk_ulp_ddp_data     ULP direct data placement private data
> >>   * @icsk_listen_portaddr_node  hash to the portaddr listener hashtable
> >>   * @icsk_ca_state:        Congestion control state
> >>   * @icsk_retransmits:     Number of unrecovered [RTO] timeouts
> >> @@ -94,6 +96,8 @@ struct inet_connection_sock {
> >>         const struct tcp_ulp_ops  *icsk_ulp_ops;
> >>         void __rcu                *icsk_ulp_data;
> >>         void (*icsk_clean_acked)(struct sock *sk, u32 acked_seq);
> >
> > #ifdef CONFIG_TCP_DDP ?
> >
> >> +       const struct tcp_ddp_ulp_ops  *icsk_ulp_ddp_ops;
> >> +       void __rcu                *icsk_ulp_ddp_data;
> >>         struct hlist_node         icsk_listen_portaddr_node;
> >>         unsigned int              (*icsk_sync_mss)(struct sock *sk, u32 pmtu);
> >>         __u8                      icsk_ca_state:5,
> >> diff --git a/include/net/tcp_ddp.h b/include/net/tcp_ddp.h
> >> new file mode 100644
> >> index 000000000000..31e5b1a16d0f
> >> --- /dev/null
> >> +++ b/include/net/tcp_ddp.h
> >> @@ -0,0 +1,136 @@
> >> +/* SPDX-License-Identifier: GPL-2.0
> >> + *
> >> + * tcp_ddp.h
> >> + *     Author: Boris Pismenny <borisp@mellanox.com>
> >> + *     Copyright (C) 2021 Mellanox Technologies.
> >> + */
> >> +#ifndef _TCP_DDP_H
> >> +#define _TCP_DDP_H
> >> +
> >> +#include <linux/netdevice.h>
> >> +#include <net/inet_connection_sock.h>
> >> +#include <net/sock.h>
> >> +
> >> +/* limits returned by the offload driver, zero means don't care */
> >> +struct tcp_ddp_limits {
> >> +       int      max_ddp_sgl_len;
> >> +};
> >> +
> >> +enum tcp_ddp_type {
> >> +       TCP_DDP_NVME = 1,
> >> +};
> >> +
> >> +/**
> >> + * struct tcp_ddp_config - Generic tcp ddp configuration: tcp ddp IO queue
> >> + * config implementations must use this as the first member.
> >> + * Add new instances of tcp_ddp_config below (nvme-tcp, etc.).
> >> + */
> >> +struct tcp_ddp_config {
> >> +       enum tcp_ddp_type    type;
> >> +       unsigned char        buf[];
> >> +};
> >> +
> >> +/**
> >> + * struct nvme_tcp_ddp_config - nvme tcp ddp configuration for an IO queue
> >> + *
> >> + * @pfv:        pdu version (e.g., NVME_TCP_PFV_1_0)
> >> + * @cpda:       controller pdu data alignmend (dwords, 0's based)
> >> + * @dgst:       digest types enabled.
> >> + *              The netdev will offload crc if ddp_crc is supported.
> >> + * @queue_size: number of nvme-tcp IO queue elements
> >> + * @queue_id:   queue identifier
> >> + * @cpu_io:     cpu core running the IO thread for this queue
> >> + */
> >> +struct nvme_tcp_ddp_config {
> >> +       struct tcp_ddp_config   cfg;
> >> +
> >> +       u16                     pfv;
> >> +       u8                      cpda;
> >> +       u8                      dgst;
> >> +       int                     queue_size;
> >> +       int                     queue_id;
> >> +       int                     io_cpu;
> >> +};
> >> +
> >> +/**
> >> + * struct tcp_ddp_io - tcp ddp configuration for an IO request.
> >> + *
> >> + * @command_id:  identifier on the wire associated with these buffers
> >> + * @nents:       number of entries in the sg_table
> >> + * @sg_table:    describing the buffers for this IO request
> >> + * @first_sgl:   first SGL in sg_table
> >> + */
> >> +struct tcp_ddp_io {
> >> +       u32                     command_id;
> >> +       int                     nents;
> >> +       struct sg_table         sg_table;
> >> +       struct scatterlist      first_sgl[SG_CHUNK_SIZE];
> >> +};
> >> +
> >> +/* struct tcp_ddp_dev_ops - operations used by an upper layer protocol to configure ddp offload
> >> + *
> >> + * @tcp_ddp_limits:    limit the number of scatter gather entries per IO.
> >> + *                     the device driver can use this to limit the resources allocated per queue.
> >> + * @tcp_ddp_sk_add:    add offload for the queue represennted by the socket+config pair.
> >> + *                     this function is used to configure either copy, crc or both offloads.
> >> + * @tcp_ddp_sk_del:    remove offload from the socket, and release any device related resources.
> >> + * @tcp_ddp_setup:     request copy offload for buffers associated with a command_id in tcp_ddp_io.
> >> + * @tcp_ddp_teardown:  release offload resources association between buffers and command_id in
> >> + *                     tcp_ddp_io.
> >> + * @tcp_ddp_resync:    respond to the driver's resync_request. Called only if resync is successful.
> >> + */
> >> +struct tcp_ddp_dev_ops {
> >> +       int (*tcp_ddp_limits)(struct net_device *netdev,
> >> +                             struct tcp_ddp_limits *limits);
> >> +       int (*tcp_ddp_sk_add)(struct net_device *netdev,
> >> +                             struct sock *sk,
> >> +                             struct tcp_ddp_config *config);
> >> +       void (*tcp_ddp_sk_del)(struct net_device *netdev,
> >> +                              struct sock *sk);
> >> +       int (*tcp_ddp_setup)(struct net_device *netdev,
> >> +                            struct sock *sk,
> >> +                            struct tcp_ddp_io *io);
> >> +       int (*tcp_ddp_teardown)(struct net_device *netdev,
> >> +                               struct sock *sk,
> >> +                               struct tcp_ddp_io *io,
> >> +                               void *ddp_ctx);
> >> +       void (*tcp_ddp_resync)(struct net_device *netdev,
> >> +                              struct sock *sk, u32 seq);
> >> +};
> >> +
> >> +#define TCP_DDP_RESYNC_REQ BIT(0)
> >> +
> >> +/**
> >> + * struct tcp_ddp_ulp_ops - Interface to register uppper layer Direct Data Placement (DDP) TCP offload
> >> + */
> >> +struct tcp_ddp_ulp_ops {
> >> +       /* NIC requests ulp to indicate if @seq is the start of a message */
> >> +       bool (*resync_request)(struct sock *sk, u32 seq, u32 flags);
> >> +       /* NIC driver informs the ulp that ddp teardown is done - used for async completions*/
> >> +       void (*ddp_teardown_done)(void *ddp_ctx);
> >> +};
> >> +
> >> +/**
> >> + * struct tcp_ddp_ctx - Generic tcp ddp context: device driver per queue contexts must
> >> + * use this as the first member.
> >> + */
> >> +struct tcp_ddp_ctx {
> >> +       enum tcp_ddp_type    type;
> >> +       unsigned char        buf[];
> >> +};
> >> +
> >> +static inline struct tcp_ddp_ctx *tcp_ddp_get_ctx(const struct sock *sk)
> >> +{
> >> +       struct inet_connection_sock *icsk = inet_csk(sk);
> >> +
> >> +       return (__force struct tcp_ddp_ctx *)icsk->icsk_ulp_ddp_data;
> >> +}
> >> +
> >> +static inline void tcp_ddp_set_ctx(struct sock *sk, void *ctx)
> >> +{
> >> +       struct inet_connection_sock *icsk = inet_csk(sk);
> >> +
> >> +       rcu_assign_pointer(icsk->icsk_ulp_ddp_data, ctx);
> >> +}
> >> +
> >> +#endif //_TCP_DDP_H
> >> diff --git a/net/Kconfig b/net/Kconfig
> >> index f4c32d982af6..3876861cdc90 100644
> >> --- a/net/Kconfig
> >> +++ b/net/Kconfig
> >> @@ -457,6 +457,15 @@ config ETHTOOL_NETLINK
> >>           netlink. It provides better extensibility and some new features,
> >>           e.g. notification messages.
> >>
> >> +config TCP_DDP
> >> +       bool "TCP direct data placement offload"
> >> +       default n
> >> +       help
> >> +         Direct Data Placement (DDP) offload for TCP enables ULP, such as
> >> +         NVMe-TCP/iSCSI, to request the NIC to place TCP payload data
> >> +         of a command response directly into kernel pages.
> >> +
> >> +
> >>  endif   # if NET
> >>
> >>  # Used by archs to tell that they support BPF JIT compiler plus which flavour.
> >> diff --git a/net/core/skbuff.c b/net/core/skbuff.c
> >> index f62cae3f75d8..791c1b6bc067 100644
> >> --- a/net/core/skbuff.c
> >> +++ b/net/core/skbuff.c
> >> @@ -69,6 +69,7 @@
> >>  #include <net/xfrm.h>
> >>  #include <net/mpls.h>
> >>  #include <net/mptcp.h>
> >> +#include <net/tcp_ddp.h>
> >>
> >>  #include <linux/uaccess.h>
> >>  #include <trace/events/skb.h>
> >> @@ -6140,9 +6141,15 @@ EXPORT_SYMBOL(pskb_extract);
> >>   */
> >>  void skb_condense(struct sk_buff *skb)
> >>  {
> >> +       bool is_ddp = false;
> >> +
> >> +#ifdef CONFIG_TCP_DDP
> >
> > This looks strange to me : TCP should call this helper while skb->sk is NULL
> >
> > Are you sure this is not dead code ?
> >
>
> Will verify again on Sunday. AFAICT, early demux sets skb->sk before this code
> is called.


First, early demux is optional.

Secondly, skb->sk is stolen in skb_steal_sock() if early demux was performed.


Just to clarify, the purpose of this code is to avoid skb condensing
> data that is already placed into destination buffers.

Then this has not been tested. This suggests this code could be
removed, I doubt that your target traffic would ever be 'condensed'.

>
> >> +       is_ddp = skb->sk && inet_csk(skb->sk) &&
> >> +                inet_csk(skb->sk)->icsk_ulp_ddp_data;
> >> +#endif
> >>         if (skb->data_len) {
> >>                 if (skb->data_len > skb->end - skb->tail ||
> >> -                   skb_cloned(skb))
> >> +                   skb_cloned(skb) || is_ddp)
> >>                         return;
> >>
> >>                 /* Nice, we can free page frag(s) right now */
> >> diff --git a/net/ethtool/common.c b/net/ethtool/common.c
> >> index 24036e3055a1..a2ff7a4a6bbf 100644
> >> --- a/net/ethtool/common.c
> >> +++ b/net/ethtool/common.c
> >> @@ -68,6 +68,7 @@ const char netdev_features_strings[NETDEV_FEATURE_COUNT][ETH_GSTRING_LEN] = {
> >>         [NETIF_F_HW_TLS_RX_BIT] =        "tls-hw-rx-offload",
> >>         [NETIF_F_GRO_FRAGLIST_BIT] =     "rx-gro-list",
> >>         [NETIF_F_HW_MACSEC_BIT] =        "macsec-hw-offload",
> >> +       [NETIF_F_HW_TCP_DDP_BIT] =       "tcp-ddp-offload",
> >>  };
> >>
> >>  const char
> >> --
> >> 2.24.1
> >>

Re: [PATCH v2 net-next 19/21] net/mlx5e: NVMEoTCP, data-path for DDP offload

[David Ahern]

I have not had time to review this version of the patches, but this
patch seems very similar to 13 of 15 from v1 and you did not respond to
my question on it ...

On 1/14/21 8:10 AM, Boris Pismenny wrote:
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp_rxtx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp_rxtx.c
> new file mode 100644
> index 000000000000..f446b5d56d64
> --- /dev/null
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp_rxtx.c
> @@ -0,0 +1,243 @@
> +// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
> +/* Copyright (c) 2021 Mellanox Technologies. */
> +
> +#include "en_accel/nvmeotcp_rxtx.h"
> +#include "en_accel/nvmeotcp.h"
> +#include <linux/mlx5/mlx5_ifc.h>
> +
> +#define	MLX5E_TC_FLOW_ID_MASK  0x00ffffff
> +static void nvmeotcp_update_resync(struct mlx5e_nvmeotcp_queue *queue,
> +				   struct mlx5e_cqe128 *cqe128)
> +{
> +	const struct tcp_ddp_ulp_ops *ulp_ops;
> +	u32 seq;
> +
> +	seq = be32_to_cpu(cqe128->resync_tcp_sn);
> +	ulp_ops = inet_csk(queue->sk)->icsk_ulp_ddp_ops;
> +	if (ulp_ops && ulp_ops->resync_request)
> +		ulp_ops->resync_request(queue->sk, seq, TCP_DDP_RESYNC_REQ);
> +}
> +
> +static void mlx5e_nvmeotcp_advance_sgl_iter(struct mlx5e_nvmeotcp_queue *queue)
> +{
> +	struct nvmeotcp_queue_entry *nqe = &queue->ccid_table[queue->ccid];
> +
> +	queue->ccoff += nqe->sgl[queue->ccsglidx].length;
> +	queue->ccoff_inner = 0;
> +	queue->ccsglidx++;
> +}
> +
> +static inline void
> +mlx5e_nvmeotcp_add_skb_frag(struct net_device *netdev, struct sk_buff *skb,
> +			    struct mlx5e_nvmeotcp_queue *queue,
> +			    struct nvmeotcp_queue_entry *nqe, u32 fragsz)
> +{
> +	dma_sync_single_for_cpu(&netdev->dev,
> +				nqe->sgl[queue->ccsglidx].offset + queue->ccoff_inner,
> +				fragsz, DMA_FROM_DEVICE);
> +	page_ref_inc(compound_head(sg_page(&nqe->sgl[queue->ccsglidx])));
> +	// XXX: consider reducing the truesize, as no new memory is consumed
> +	skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
> +			sg_page(&nqe->sgl[queue->ccsglidx]),
> +			nqe->sgl[queue->ccsglidx].offset + queue->ccoff_inner,
> +			fragsz,
> +			fragsz);
> +}
> +
> +static struct sk_buff*
> +mlx5_nvmeotcp_add_tail_nonlinear(struct mlx5e_nvmeotcp_queue *queue,
> +				 struct sk_buff *skb, skb_frag_t *org_frags,
> +				 int org_nr_frags, int frag_index)
> +{
> +	struct mlx5e_priv *priv = queue->priv;
> +
> +	while (org_nr_frags != frag_index) {
> +		if (skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS) {
> +			dev_kfree_skb_any(skb);
> +			return NULL;
> +		}
> +		skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
> +				skb_frag_page(&org_frags[frag_index]),
> +				skb_frag_off(&org_frags[frag_index]),
> +				skb_frag_size(&org_frags[frag_index]),
> +				skb_frag_size(&org_frags[frag_index]));
> +		page_ref_inc(skb_frag_page(&org_frags[frag_index]));
> +		frag_index++;
> +	}
> +	return skb;
> +}
> +
> +static struct sk_buff*
> +mlx5_nvmeotcp_add_tail(struct mlx5e_nvmeotcp_queue *queue, struct sk_buff *skb,
> +		       int offset, int len)
> +{
> +	struct mlx5e_priv *priv = queue->priv;
> +
> +	if (skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS) {
> +		dev_kfree_skb_any(skb);
> +		return NULL;
> +	}
> +	skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
> +			virt_to_page(skb->data),
> +			offset,
> +			len,
> +			len);
> +	page_ref_inc(virt_to_page(skb->data));
> +	return skb;
> +}
> +
> +static void mlx5_nvmeotcp_trim_nonlinear(struct sk_buff *skb,
> +					 skb_frag_t *org_frags,
> +					 int *frag_index,
> +					 int remaining)
> +{
> +	unsigned int frag_size;
> +	int nr_frags;
> +
> +	/* skip @remaining bytes in frags */
> +	*frag_index = 0;
> +	while (remaining) {
> +		frag_size = skb_frag_size(&skb_shinfo(skb)->frags[*frag_index]);
> +		if (frag_size > remaining) {
> +			skb_frag_off_add(&skb_shinfo(skb)->frags[*frag_index],
> +					 remaining);
> +			skb_frag_size_sub(&skb_shinfo(skb)->frags[*frag_index],
> +					  remaining);
> +			remaining = 0;
> +		} else {
> +			remaining -= frag_size;
> +			skb_frag_unref(skb, *frag_index);
> +			*frag_index += 1;
> +		}
> +	}
> +
> +	/* save original frags for the tail and unref */
> +	nr_frags = skb_shinfo(skb)->nr_frags;
> +	memcpy(&org_frags[*frag_index], &skb_shinfo(skb)->frags[*frag_index],
> +	       (nr_frags - *frag_index) * sizeof(skb_frag_t));
> +	while (--nr_frags >= *frag_index)
> +		skb_frag_unref(skb, nr_frags);
> +
> +	/* remove frags from skb */
> +	skb_shinfo(skb)->nr_frags = 0;
> +	skb->len -= skb->data_len;
> +	skb->truesize -= skb->data_len;
> +	skb->data_len = 0;
> +}
> +
> +struct sk_buff*
> +mlx5e_nvmeotcp_handle_rx_skb(struct net_device *netdev, struct sk_buff *skb,
> +			     struct mlx5_cqe64 *cqe, u32 cqe_bcnt,
> +			     bool linear)
> +{
> +	int ccoff, cclen, hlen, ccid, remaining, fragsz, to_copy = 0;
> +	struct mlx5e_priv *priv = netdev_priv(netdev);
> +	skb_frag_t org_frags[MAX_SKB_FRAGS];
> +	struct mlx5e_nvmeotcp_queue *queue;
> +	struct nvmeotcp_queue_entry *nqe;
> +	int org_nr_frags, frag_index;
> +	struct mlx5e_cqe128 *cqe128;
> +	u32 queue_id;
> +
> +	queue_id = (be32_to_cpu(cqe->sop_drop_qpn) & MLX5E_TC_FLOW_ID_MASK);
> +	queue = mlx5e_nvmeotcp_get_queue(priv->nvmeotcp, queue_id);
> +	if (unlikely(!queue)) {
> +		dev_kfree_skb_any(skb);
> +		return NULL;
> +	}
> +
> +	cqe128 = container_of(cqe, struct mlx5e_cqe128, cqe64);
> +	if (cqe_is_nvmeotcp_resync(cqe)) {
> +		nvmeotcp_update_resync(queue, cqe128);
> +		mlx5e_nvmeotcp_put_queue(queue);
> +		return skb;
> +	}
> +
> +#ifdef CONFIG_TCP_DDP_CRC
> +	/* If a resync occurred in the previous cqe,
> +	 * the current cqe.crcvalid bit may not be valid,
> +	 * so we will treat it as 0
> +	 */
> +	skb->ddp_crc = queue->after_resync_cqe ? 0 :
> +		cqe_is_nvmeotcp_crcvalid(cqe);
> +	queue->after_resync_cqe = 0;
> +#endif
> +	if (!cqe_is_nvmeotcp_zc(cqe)) {
> +		mlx5e_nvmeotcp_put_queue(queue);
> +		return skb;
> +	}
> +
> +	/* cc ddp from cqe */
> +	ccid = be16_to_cpu(cqe128->ccid);
> +	ccoff = be32_to_cpu(cqe128->ccoff);
> +	cclen = be16_to_cpu(cqe128->cclen);
> +	hlen  = be16_to_cpu(cqe128->hlen);
> +
> +	/* carve a hole in the skb for DDP data */
> +	if (linear) {
> +		skb_trim(skb, hlen);
> +	} else {
> +		org_nr_frags = skb_shinfo(skb)->nr_frags;
> +		mlx5_nvmeotcp_trim_nonlinear(skb, org_frags, &frag_index,
> +					     cclen);
> +	}
> +
> +	nqe = &queue->ccid_table[ccid];
> +
> +	/* packet starts new ccid? */
> +	if (queue->ccid != ccid || queue->ccid_gen != nqe->ccid_gen) {
> +		queue->ccid = ccid;
> +		queue->ccoff = 0;
> +		queue->ccoff_inner = 0;
> +		queue->ccsglidx = 0;
> +		queue->ccid_gen = nqe->ccid_gen;
> +	}
> +
> +	/* skip inside cc until the ccoff in the cqe */
> +	while (queue->ccoff + queue->ccoff_inner < ccoff) {
> +		remaining = nqe->sgl[queue->ccsglidx].length - queue->ccoff_inner;
> +		fragsz = min_t(off_t, remaining,
> +			       ccoff - (queue->ccoff + queue->ccoff_inner));
> +
> +		if (fragsz == remaining)
> +			mlx5e_nvmeotcp_advance_sgl_iter(queue);
> +		else
> +			queue->ccoff_inner += fragsz;
> +	}
> +
> +	/* adjust the skb according to the cqe cc */
> +	while (to_copy < cclen) {
> +		if (skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS) {
> +			dev_kfree_skb_any(skb);
> +			mlx5e_nvmeotcp_put_queue(queue);
> +			return NULL;
> +		}
> +
> +		remaining = nqe->sgl[queue->ccsglidx].length - queue->ccoff_inner;
> +		fragsz = min_t(int, remaining, cclen - to_copy);
> +
> +		mlx5e_nvmeotcp_add_skb_frag(netdev, skb, queue, nqe, fragsz);
> +		to_copy += fragsz;
> +		if (fragsz == remaining)
> +			mlx5e_nvmeotcp_advance_sgl_iter(queue);
> +		else
> +			queue->ccoff_inner += fragsz;
> +	}
> +
> +	if (cqe_bcnt > hlen + cclen) {
> +		remaining = cqe_bcnt - hlen - cclen;
> +		if (linear)
> +			skb = mlx5_nvmeotcp_add_tail(queue, skb,
> +						     offset_in_page(skb->data) +
> +								hlen + cclen,
> +						     remaining);
> +		else
> +			skb = mlx5_nvmeotcp_add_tail_nonlinear(queue, skb,
> +							       org_frags,
> +							       org_nr_frags,
> +							       frag_index);
> +	}
> +
> +	mlx5e_nvmeotcp_put_queue(queue);
> +	return skb;
> +}



... I'll copy and paste my question here:

"mlx5e_skb_from_cqe_mpwrq_linear and mlx5e_skb_from_cqe_mpwrq_nolinear
create an skb and then this function comes behind it, strips any frags
originally added to the skb, adds the frags for the sgls, and then
re-adds the original frags.

Why is this needed? Why can't the skb be created with all of the frags
in proper order?

It seems like this dance is not needed if you had generic header/payload
splits with the payload written to less retrictive SGLs."

This patch seems to be something very similar, and it is really
complicated way to create each skb for DDP. The patch description does
little to explain why it is needed.

Re: [PATCH v2 net-next 19/21] net/mlx5e: NVMEoTCP, data-path for DDP offload

[Boris Pismenny]

On 16/01/2021 6:57, David Ahern wrote:
> I have not had time to review this version of the patches, but this
> patch seems very similar to 13 of 15 from v1 and you did not respond to
> my question on it ...
> 
> On 1/14/21 8:10 AM, Boris Pismenny wrote:
>> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp_rxtx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp_rxtx.c
>> new file mode 100644
>> index 000000000000..f446b5d56d64
>> --- /dev/null
>> +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/nvmeotcp_rxtx.c
>> @@ -0,0 +1,243 @@
>> +// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
>> +/* Copyright (c) 2021 Mellanox Technologies. */
>> +
>> +#include "en_accel/nvmeotcp_rxtx.h"
>> +#include "en_accel/nvmeotcp.h"
>> +#include <linux/mlx5/mlx5_ifc.h>
>> +
>> +#define	MLX5E_TC_FLOW_ID_MASK  0x00ffffff
>> +static void nvmeotcp_update_resync(struct mlx5e_nvmeotcp_queue *queue,
>> +				   struct mlx5e_cqe128 *cqe128)
>> +{
>> +	const struct tcp_ddp_ulp_ops *ulp_ops;
>> +	u32 seq;
>> +
>> +	seq = be32_to_cpu(cqe128->resync_tcp_sn);
>> +	ulp_ops = inet_csk(queue->sk)->icsk_ulp_ddp_ops;
>> +	if (ulp_ops && ulp_ops->resync_request)
>> +		ulp_ops->resync_request(queue->sk, seq, TCP_DDP_RESYNC_REQ);
>> +}
>> +
>> +static void mlx5e_nvmeotcp_advance_sgl_iter(struct mlx5e_nvmeotcp_queue *queue)
>> +{
>> +	struct nvmeotcp_queue_entry *nqe = &queue->ccid_table[queue->ccid];
>> +
>> +	queue->ccoff += nqe->sgl[queue->ccsglidx].length;
>> +	queue->ccoff_inner = 0;
>> +	queue->ccsglidx++;
>> +}
>> +
>> +static inline void
>> +mlx5e_nvmeotcp_add_skb_frag(struct net_device *netdev, struct sk_buff *skb,
>> +			    struct mlx5e_nvmeotcp_queue *queue,
>> +			    struct nvmeotcp_queue_entry *nqe, u32 fragsz)
>> +{
>> +	dma_sync_single_for_cpu(&netdev->dev,
>> +				nqe->sgl[queue->ccsglidx].offset + queue->ccoff_inner,
>> +				fragsz, DMA_FROM_DEVICE);
>> +	page_ref_inc(compound_head(sg_page(&nqe->sgl[queue->ccsglidx])));
>> +	// XXX: consider reducing the truesize, as no new memory is consumed
>> +	skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
>> +			sg_page(&nqe->sgl[queue->ccsglidx]),
>> +			nqe->sgl[queue->ccsglidx].offset + queue->ccoff_inner,
>> +			fragsz,
>> +			fragsz);
>> +}
>> +
>> +static struct sk_buff*
>> +mlx5_nvmeotcp_add_tail_nonlinear(struct mlx5e_nvmeotcp_queue *queue,
>> +				 struct sk_buff *skb, skb_frag_t *org_frags,
>> +				 int org_nr_frags, int frag_index)
>> +{
>> +	struct mlx5e_priv *priv = queue->priv;
>> +
>> +	while (org_nr_frags != frag_index) {
>> +		if (skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS) {
>> +			dev_kfree_skb_any(skb);
>> +			return NULL;
>> +		}
>> +		skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
>> +				skb_frag_page(&org_frags[frag_index]),
>> +				skb_frag_off(&org_frags[frag_index]),
>> +				skb_frag_size(&org_frags[frag_index]),
>> +				skb_frag_size(&org_frags[frag_index]));
>> +		page_ref_inc(skb_frag_page(&org_frags[frag_index]));
>> +		frag_index++;
>> +	}
>> +	return skb;
>> +}
>> +
>> +static struct sk_buff*
>> +mlx5_nvmeotcp_add_tail(struct mlx5e_nvmeotcp_queue *queue, struct sk_buff *skb,
>> +		       int offset, int len)
>> +{
>> +	struct mlx5e_priv *priv = queue->priv;
>> +
>> +	if (skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS) {
>> +		dev_kfree_skb_any(skb);
>> +		return NULL;
>> +	}
>> +	skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
>> +			virt_to_page(skb->data),
>> +			offset,
>> +			len,
>> +			len);
>> +	page_ref_inc(virt_to_page(skb->data));
>> +	return skb;
>> +}
>> +
>> +static void mlx5_nvmeotcp_trim_nonlinear(struct sk_buff *skb,
>> +					 skb_frag_t *org_frags,
>> +					 int *frag_index,
>> +					 int remaining)
>> +{
>> +	unsigned int frag_size;
>> +	int nr_frags;
>> +
>> +	/* skip @remaining bytes in frags */
>> +	*frag_index = 0;
>> +	while (remaining) {
>> +		frag_size = skb_frag_size(&skb_shinfo(skb)->frags[*frag_index]);
>> +		if (frag_size > remaining) {
>> +			skb_frag_off_add(&skb_shinfo(skb)->frags[*frag_index],
>> +					 remaining);
>> +			skb_frag_size_sub(&skb_shinfo(skb)->frags[*frag_index],
>> +					  remaining);
>> +			remaining = 0;
>> +		} else {
>> +			remaining -= frag_size;
>> +			skb_frag_unref(skb, *frag_index);
>> +			*frag_index += 1;
>> +		}
>> +	}
>> +
>> +	/* save original frags for the tail and unref */
>> +	nr_frags = skb_shinfo(skb)->nr_frags;
>> +	memcpy(&org_frags[*frag_index], &skb_shinfo(skb)->frags[*frag_index],
>> +	       (nr_frags - *frag_index) * sizeof(skb_frag_t));
>> +	while (--nr_frags >= *frag_index)
>> +		skb_frag_unref(skb, nr_frags);
>> +
>> +	/* remove frags from skb */
>> +	skb_shinfo(skb)->nr_frags = 0;
>> +	skb->len -= skb->data_len;
>> +	skb->truesize -= skb->data_len;
>> +	skb->data_len = 0;
>> +}
>> +
>> +struct sk_buff*
>> +mlx5e_nvmeotcp_handle_rx_skb(struct net_device *netdev, struct sk_buff *skb,
>> +			     struct mlx5_cqe64 *cqe, u32 cqe_bcnt,
>> +			     bool linear)
>> +{
>> +	int ccoff, cclen, hlen, ccid, remaining, fragsz, to_copy = 0;
>> +	struct mlx5e_priv *priv = netdev_priv(netdev);
>> +	skb_frag_t org_frags[MAX_SKB_FRAGS];
>> +	struct mlx5e_nvmeotcp_queue *queue;
>> +	struct nvmeotcp_queue_entry *nqe;
>> +	int org_nr_frags, frag_index;
>> +	struct mlx5e_cqe128 *cqe128;
>> +	u32 queue_id;
>> +
>> +	queue_id = (be32_to_cpu(cqe->sop_drop_qpn) & MLX5E_TC_FLOW_ID_MASK);
>> +	queue = mlx5e_nvmeotcp_get_queue(priv->nvmeotcp, queue_id);
>> +	if (unlikely(!queue)) {
>> +		dev_kfree_skb_any(skb);
>> +		return NULL;
>> +	}
>> +
>> +	cqe128 = container_of(cqe, struct mlx5e_cqe128, cqe64);
>> +	if (cqe_is_nvmeotcp_resync(cqe)) {
>> +		nvmeotcp_update_resync(queue, cqe128);
>> +		mlx5e_nvmeotcp_put_queue(queue);
>> +		return skb;
>> +	}
>> +
>> +#ifdef CONFIG_TCP_DDP_CRC
>> +	/* If a resync occurred in the previous cqe,
>> +	 * the current cqe.crcvalid bit may not be valid,
>> +	 * so we will treat it as 0
>> +	 */
>> +	skb->ddp_crc = queue->after_resync_cqe ? 0 :
>> +		cqe_is_nvmeotcp_crcvalid(cqe);
>> +	queue->after_resync_cqe = 0;
>> +#endif
>> +	if (!cqe_is_nvmeotcp_zc(cqe)) {
>> +		mlx5e_nvmeotcp_put_queue(queue);
>> +		return skb;
>> +	}
>> +
>> +	/* cc ddp from cqe */
>> +	ccid = be16_to_cpu(cqe128->ccid);
>> +	ccoff = be32_to_cpu(cqe128->ccoff);
>> +	cclen = be16_to_cpu(cqe128->cclen);
>> +	hlen  = be16_to_cpu(cqe128->hlen);
>> +
>> +	/* carve a hole in the skb for DDP data */
>> +	if (linear) {
>> +		skb_trim(skb, hlen);
>> +	} else {
>> +		org_nr_frags = skb_shinfo(skb)->nr_frags;
>> +		mlx5_nvmeotcp_trim_nonlinear(skb, org_frags, &frag_index,
>> +					     cclen);
>> +	}
>> +
>> +	nqe = &queue->ccid_table[ccid];
>> +
>> +	/* packet starts new ccid? */
>> +	if (queue->ccid != ccid || queue->ccid_gen != nqe->ccid_gen) {
>> +		queue->ccid = ccid;
>> +		queue->ccoff = 0;
>> +		queue->ccoff_inner = 0;
>> +		queue->ccsglidx = 0;
>> +		queue->ccid_gen = nqe->ccid_gen;
>> +	}
>> +
>> +	/* skip inside cc until the ccoff in the cqe */
>> +	while (queue->ccoff + queue->ccoff_inner < ccoff) {
>> +		remaining = nqe->sgl[queue->ccsglidx].length - queue->ccoff_inner;
>> +		fragsz = min_t(off_t, remaining,
>> +			       ccoff - (queue->ccoff + queue->ccoff_inner));
>> +
>> +		if (fragsz == remaining)
>> +			mlx5e_nvmeotcp_advance_sgl_iter(queue);
>> +		else
>> +			queue->ccoff_inner += fragsz;
>> +	}
>> +
>> +	/* adjust the skb according to the cqe cc */
>> +	while (to_copy < cclen) {
>> +		if (skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS) {
>> +			dev_kfree_skb_any(skb);
>> +			mlx5e_nvmeotcp_put_queue(queue);
>> +			return NULL;
>> +		}
>> +
>> +		remaining = nqe->sgl[queue->ccsglidx].length - queue->ccoff_inner;
>> +		fragsz = min_t(int, remaining, cclen - to_copy);
>> +
>> +		mlx5e_nvmeotcp_add_skb_frag(netdev, skb, queue, nqe, fragsz);
>> +		to_copy += fragsz;
>> +		if (fragsz == remaining)
>> +			mlx5e_nvmeotcp_advance_sgl_iter(queue);
>> +		else
>> +			queue->ccoff_inner += fragsz;
>> +	}
>> +
>> +	if (cqe_bcnt > hlen + cclen) {
>> +		remaining = cqe_bcnt - hlen - cclen;
>> +		if (linear)
>> +			skb = mlx5_nvmeotcp_add_tail(queue, skb,
>> +						     offset_in_page(skb->data) +
>> +								hlen + cclen,
>> +						     remaining);
>> +		else
>> +			skb = mlx5_nvmeotcp_add_tail_nonlinear(queue, skb,
>> +							       org_frags,
>> +							       org_nr_frags,
>> +							       frag_index);
>> +	}
>> +
>> +	mlx5e_nvmeotcp_put_queue(queue);
>> +	return skb;
>> +}
> 
> 
> 
> ... I'll copy and paste my question here:
> 
> "mlx5e_skb_from_cqe_mpwrq_linear and mlx5e_skb_from_cqe_mpwrq_nolinear
> create an skb and then this function comes behind it, strips any frags
> originally added to the skb, adds the frags for the sgls, and then
> re-adds the original frags.
> 
> Why is this needed? Why can't the skb be created with all of the frags
> in proper order?
> 
> It seems like this dance is not needed if you had generic header/payload
> splits with the payload written to less retrictive SGLs."
> 
> This patch seems to be something very similar, and it is really
> complicated way to create each skb for DDP. The patch description does
> little to explain why it is needed.
> 

This is the same patch as before.

I'll start by explaining why this is needed. Then, clarify why generic
header-data split is not enough.

This is needed for a few reasons that are explained in detail
in the tcp-ddp offload documentation. See patch 21 overview
and rx-data-path sections. Our reasons are as follows:
1) Each SKB may contain multiple PDUs. DDP offload doesn't operate on
PDU headers, so these are written in the receive ring. Therefore, we
need to rebuild the SKB to account for it. Additionally, due to HW
limitations, we will only offload the first PDU in the SKB.
2) The newly constructed SKB represents the original data as it is on
the wire, such that the network stack is oblivious to the offload.
3) We decided not to modify all of the mlx5e_skb_from_cqe* functions
because it would make the offload harder to distinguish, and it would
add overhead to the existing data-path fucntions. Therefore, we opted
for this modular approach.

If we only had generic header-data split, then we just couldn't
provide this offload. It is not enough to place payload into some
buffer without TCP headers because RPC protocols and advanced storage
protocols, such as nvme-tcp, reorder their responses and require data
to be placed into application/pagecache buffers, which are anything
but anonymous. In other words, header-data split alone writes data
to the wrong buffers (reordering), or to anonymous buffers that
can't be page-flipped to replace application/pagecache buffers.

Re: [PATCH v2 net-next 06/21] nvme-tcp: Add DDP offload control path

[David Ahern]

On 1/14/21 8:10 AM, Boris Pismenny wrote:
> +static
> +int nvme_tcp_offload_socket(struct nvme_tcp_queue *queue)
> +{
> +	struct net_device *netdev = get_netdev_for_sock(queue->sock->sk, true);
> +	struct nvme_tcp_ddp_config config = {};
> +	int ret;
> +
> +	if (!netdev) {
> +		dev_info_ratelimited(queue->ctrl->ctrl.device, "netdev not found\n");
> +		return -ENODEV;
> +	}
> +
> +	if (!(netdev->features & NETIF_F_HW_TCP_DDP)) {
> +		dev_put(netdev);
> +		return -EOPNOTSUPP;
> +	}
> +
> +	config.cfg.type		= TCP_DDP_NVME;
> +	config.pfv		= NVME_TCP_PFV_1_0;
> +	config.cpda		= 0;
> +	config.dgst		= queue->hdr_digest ?
> +		NVME_TCP_HDR_DIGEST_ENABLE : 0;
> +	config.dgst		|= queue->data_digest ?
> +		NVME_TCP_DATA_DIGEST_ENABLE : 0;
> +	config.queue_size	= queue->queue_size;
> +	config.queue_id		= nvme_tcp_queue_id(queue);
> +	config.io_cpu		= queue->io_cpu;
> +
> +	ret = netdev->tcp_ddp_ops->tcp_ddp_sk_add(netdev,
> +						  queue->sock->sk,
> +						  (struct tcp_ddp_config *)&config);

typecast is not needed; tcp_ddp_config is an element of nvme_tcp_ddp_config

> +	if (ret) {
> +		dev_put(netdev);
> +		return ret;
> +	}
> +
> +	inet_csk(queue->sock->sk)->icsk_ulp_ddp_ops = &nvme_tcp_ddp_ulp_ops;
> +	if (netdev->features & NETIF_F_HW_TCP_DDP)
> +		set_bit(NVME_TCP_Q_OFF_DDP, &queue->flags);
> +
> +	return ret;
> +}
> +
> +static
> +void nvme_tcp_unoffload_socket(struct nvme_tcp_queue *queue)
> +{
> +	struct net_device *netdev = queue->ctrl->offloading_netdev;
> +
> +	if (!netdev) {
> +		dev_info_ratelimited(queue->ctrl->ctrl.device, "netdev not found\n");
> +		return;
> +	}
> +
> +	netdev->tcp_ddp_ops->tcp_ddp_sk_del(netdev, queue->sock->sk);
> +
> +	inet_csk(queue->sock->sk)->icsk_ulp_ddp_ops = NULL;
> +	dev_put(netdev); /* put the queue_init get_netdev_for_sock() */

have you validated the netdev reference counts? You have a put here, and ...

> +}
> +
> +static
> +int nvme_tcp_offload_limits(struct nvme_tcp_queue *queue)
> +{
> +	struct net_device *netdev = get_netdev_for_sock(queue->sock->sk, true);

... a get here ....

> +	struct tcp_ddp_limits limits;
> +	int ret = 0;
> +
> +	if (!netdev) {
> +		dev_info_ratelimited(queue->ctrl->ctrl.device, "netdev not found\n");
> +		return -ENODEV;
> +	}
> +
> +	if (netdev->features & NETIF_F_HW_TCP_DDP &&
> +	    netdev->tcp_ddp_ops &&
> +	    netdev->tcp_ddp_ops->tcp_ddp_limits)
> +		ret = netdev->tcp_ddp_ops->tcp_ddp_limits(netdev, &limits);
> +	else
> +		ret = -EOPNOTSUPP;
> +
> +	if (!ret) {
> +		queue->ctrl->offloading_netdev = netdev;


... you have the device here, but then ...

> +		dev_dbg_ratelimited(queue->ctrl->ctrl.device,
> +				    "netdev %s offload limits: max_ddp_sgl_len %d\n",
> +				    netdev->name, limits.max_ddp_sgl_len);
> +		queue->ctrl->ctrl.max_segments = limits.max_ddp_sgl_len;
> +		queue->ctrl->ctrl.max_hw_sectors =
> +			limits.max_ddp_sgl_len << (ilog2(SZ_4K) - 9);
> +	} else {
> +		queue->ctrl->offloading_netdev = NULL;
> +	}
> +
> +	dev_put(netdev);

... put here. And this is the limit checking function which seems like
an odd place to set offloading_netdev vs nvme_tcp_offload_socket which
sets no queue variable but yet hangs on to a netdev reference count.

netdev reference count leaks are an absolute PITA to find. Code that
takes and puts the counts should be clear and obvious as to when and
why. The symmetry of offload and unoffload are clear when the offload
saves the address in offloading_netdev. What you have now is dubious.

Re: [PATCH v2 net-next 07/21] nvme-tcp: Add DDP data-path

[David Ahern]

On 1/14/21 8:10 AM, Boris Pismenny wrote:
> @@ -664,8 +753,15 @@ static int nvme_tcp_process_nvme_cqe(struct nvme_tcp_queue *queue,
>  		return -EINVAL;
>  	}
>  
> -	if (!nvme_try_complete_req(rq, cqe->status, cqe->result))
> -		nvme_complete_rq(rq);
> +	req = blk_mq_rq_to_pdu(rq);
> +	if (req->offloaded) {
> +		req->status = cqe->status;
> +		req->result = cqe->result;
> +		nvme_tcp_teardown_ddp(queue, cqe->command_id, rq);
> +	} else {
> +		if (!nvme_try_complete_req(rq, cqe->status, cqe->result))
> +			nvme_complete_rq(rq);
> +	}
>  	queue->nr_cqe++;
>  
>  	return 0;
> @@ -859,9 +955,18 @@ static int nvme_tcp_recv_pdu(struct nvme_tcp_queue *queue, struct sk_buff *skb,
>  static inline void nvme_tcp_end_request(struct request *rq, u16 status)
>  {
>  	union nvme_result res = {};
> +	struct nvme_tcp_request *req = blk_mq_rq_to_pdu(rq);
> +	struct nvme_tcp_queue *queue = req->queue;
> +	struct nvme_tcp_data_pdu *pdu = (void *)queue->pdu;
>  
> -	if (!nvme_try_complete_req(rq, cpu_to_le16(status << 1), res))
> -		nvme_complete_rq(rq);
> +	if (req->offloaded) {
> +		req->status = cpu_to_le16(status << 1);
> +		req->result = res;
> +		nvme_tcp_teardown_ddp(queue, pdu->command_id, rq);
> +	} else {
> +		if (!nvme_try_complete_req(rq, cpu_to_le16(status << 1), res))
> +			nvme_complete_rq(rq);
> +	}
>  }
>  
>  static int nvme_tcp_recv_data(struct nvme_tcp_queue *queue, struct sk_buff *skb,


The req->offload checks assume the offload is to the expected
offload_netdev, but you do not verify the data arrived as expected. You
might get lucky if both netdev's belong to the same PCI device (assuming
the h/w handles it a certain way), but it will not if the netdev's
belong to different devices.

Consider a system with 2 network cards -- even if it is 2 mlx5 based
devices. One setup can have the system using a bond with 1 port from
each PCI device. The tx path picks a leg based on the hash of the ntuple
and that (with Tariq's bond patches) becomes the expected offload
device. A similar example holds for a pure routing setup with ECMP. For
both there is full redundancy in the network - separate NIC cards
connected to separate TORs to have independent network paths.

A packet arrives on the *other* netdevice - you have *no* control over
the Rx path. Your current checks will think the packet arrived with DDP
but it did not.

Re: [PATCH v2 net-next 19/21] net/mlx5e: NVMEoTCP, data-path for DDP offload

[David Ahern]

On 1/17/21 1:42 AM, Boris Pismenny wrote:
> This is needed for a few reasons that are explained in detail
> in the tcp-ddp offload documentation. See patch 21 overview
> and rx-data-path sections. Our reasons are as follows:

I read the documentation patch, and it does not explain it and really
should not since this is very mlx specific based on the changes.
Different h/w will have different limitations. Given that, it would be
best to enhance the patch description to explain why these gymnastics
are needed for the skb.

> 1) Each SKB may contain multiple PDUs. DDP offload doesn't operate on
> PDU headers, so these are written in the receive ring. Therefore, we
> need to rebuild the SKB to account for it. Additionally, due to HW
> limitations, we will only offload the first PDU in the SKB.

Are you referring to LRO skbs here? I can't imagine going through this
for 1500 byte packets that have multiple PDUs.


> 2) The newly constructed SKB represents the original data as it is on
> the wire, such that the network stack is oblivious to the offload.
> 3) We decided not to modify all of the mlx5e_skb_from_cqe* functions
> because it would make the offload harder to distinguish, and it would
> add overhead to the existing data-path fucntions. Therefore, we opted
> for this modular approach.
> 
> If we only had generic header-data split, then we just couldn't
> provide this offload. It is not enough to place payload into some
> buffer without TCP headers because RPC protocols and advanced storage
> protocols, such as nvme-tcp, reorder their responses and require data
> to be placed into application/pagecache buffers, which are anything
> but anonymous. In other words, header-data split alone writes data
> to the wrong buffers (reordering), or to anonymous buffers that
> can't be page-flipped to replace application/pagecache buffers.
> 

Re: [PATCH v2 net-next 06/21] nvme-tcp: Add DDP offload control path

[Boris Pismenny]

On 19/01/2021 5:47, David Ahern wrote:
> On 1/14/21 8:10 AM, Boris Pismenny wrote:
>> +static
>> +int nvme_tcp_offload_socket(struct nvme_tcp_queue *queue)
>> +{
>> +	struct net_device *netdev = get_netdev_for_sock(queue->sock->sk, true);
>> +	struct nvme_tcp_ddp_config config = {};
>> +	int ret;
>> +
>> +	if (!netdev) {
>> +		dev_info_ratelimited(queue->ctrl->ctrl.device, "netdev not found\n");
>> +		return -ENODEV;
>> +	}
>> +
>> +	if (!(netdev->features & NETIF_F_HW_TCP_DDP)) {
>> +		dev_put(netdev);
>> +		return -EOPNOTSUPP;
>> +	}
>> +
>> +	config.cfg.type		= TCP_DDP_NVME;
>> +	config.pfv		= NVME_TCP_PFV_1_0;
>> +	config.cpda		= 0;
>> +	config.dgst		= queue->hdr_digest ?
>> +		NVME_TCP_HDR_DIGEST_ENABLE : 0;
>> +	config.dgst		|= queue->data_digest ?
>> +		NVME_TCP_DATA_DIGEST_ENABLE : 0;
>> +	config.queue_size	= queue->queue_size;
>> +	config.queue_id		= nvme_tcp_queue_id(queue);
>> +	config.io_cpu		= queue->io_cpu;
>> +
>> +	ret = netdev->tcp_ddp_ops->tcp_ddp_sk_add(netdev,
>> +						  queue->sock->sk,
>> +						  (struct tcp_ddp_config *)&config);
> 
> typecast is not needed; tcp_ddp_config is an element of nvme_tcp_ddp_config
> 

True, will fix, thanks!

>> +	if (ret) {
>> +		dev_put(netdev);
>> +		return ret;
>> +	}
>> +
>> +	inet_csk(queue->sock->sk)->icsk_ulp_ddp_ops = &nvme_tcp_ddp_ulp_ops;
>> +	if (netdev->features & NETIF_F_HW_TCP_DDP)
>> +		set_bit(NVME_TCP_Q_OFF_DDP, &queue->flags);
>> +
>> +	return ret;
>> +}
>> +
>> +static
>> +void nvme_tcp_unoffload_socket(struct nvme_tcp_queue *queue)
>> +{
>> +	struct net_device *netdev = queue->ctrl->offloading_netdev;
>> +
>> +	if (!netdev) {
>> +		dev_info_ratelimited(queue->ctrl->ctrl.device, "netdev not found\n");
>> +		return;
>> +	}
>> +
>> +	netdev->tcp_ddp_ops->tcp_ddp_sk_del(netdev, queue->sock->sk);
>> +
>> +	inet_csk(queue->sock->sk)->icsk_ulp_ddp_ops = NULL;
>> +	dev_put(netdev); /* put the queue_init get_netdev_for_sock() */
> 
> have you validated the netdev reference counts? You have a put here, and ...
> 

Yes, it does work for the cases we've tested: up/down,
connect/disconnect, and up/down during traffic. It is
unfortunate that it is not trivial to follow.
We'll add some comment to make it more clear. Also see
below.

>> +}
>> +
>> +static
>> +int nvme_tcp_offload_limits(struct nvme_tcp_queue *queue)
>> +{
>> +	struct net_device *netdev = get_netdev_for_sock(queue->sock->sk, true);
> 
> ... a get here ....
> 
>> +	struct tcp_ddp_limits limits;
>> +	int ret = 0;
>> +
>> +	if (!netdev) {
>> +		dev_info_ratelimited(queue->ctrl->ctrl.device, "netdev not found\n");
>> +		return -ENODEV;
>> +	}
>> +
>> +	if (netdev->features & NETIF_F_HW_TCP_DDP &&
>> +	    netdev->tcp_ddp_ops &&
>> +	    netdev->tcp_ddp_ops->tcp_ddp_limits)
>> +		ret = netdev->tcp_ddp_ops->tcp_ddp_limits(netdev, &limits);
>> +	else
>> +		ret = -EOPNOTSUPP;
>> +
>> +	if (!ret) {
>> +		queue->ctrl->offloading_netdev = netdev;
> 
> 
> ... you have the device here, but then ...
> 
>> +		dev_dbg_ratelimited(queue->ctrl->ctrl.device,
>> +				    "netdev %s offload limits: max_ddp_sgl_len %d\n",
>> +				    netdev->name, limits.max_ddp_sgl_len);
>> +		queue->ctrl->ctrl.max_segments = limits.max_ddp_sgl_len;
>> +		queue->ctrl->ctrl.max_hw_sectors =
>> +			limits.max_ddp_sgl_len << (ilog2(SZ_4K) - 9);
>> +	} else {
>> +		queue->ctrl->offloading_netdev = NULL;
>> +	}
>> +
>> +	dev_put(netdev);
> 
> ... put here. And this is the limit checking function which seems like
> an odd place to set offloading_netdev vs nvme_tcp_offload_socket which
> sets no queue variable but yet hangs on to a netdev reference count.
> 
> netdev reference count leaks are an absolute PITA to find. Code that
> takes and puts the counts should be clear and obvious as to when and
> why. The symmetry of offload and unoffload are clear when the offload
> saves the address in offloading_netdev. What you have now is dubious.
> 

The idea here is to rely on offload and unoffload to hold the netdev
during offload. Get limits is not offloading anything; it only queries
device limits that are then applied to the queue by the caller.
We hold the device here for only to ensure that the function is still
there when it is called, and we release it once we are done with it,
as no context is established on the NIC, and no offload takes place.

Re: [PATCH v2 net-next 07/21] nvme-tcp: Add DDP data-path

[Boris Pismenny]

On 19/01/2021 6:18, David Ahern wrote:
> On 1/14/21 8:10 AM, Boris Pismenny wrote:
>> @@ -664,8 +753,15 @@ static int nvme_tcp_process_nvme_cqe(struct nvme_tcp_queue *queue,
>>  		return -EINVAL;
>>  	}
>>  
>> -	if (!nvme_try_complete_req(rq, cqe->status, cqe->result))
>> -		nvme_complete_rq(rq);
>> +	req = blk_mq_rq_to_pdu(rq);
>> +	if (req->offloaded) {
>> +		req->status = cqe->status;
>> +		req->result = cqe->result;
>> +		nvme_tcp_teardown_ddp(queue, cqe->command_id, rq);
>> +	} else {
>> +		if (!nvme_try_complete_req(rq, cqe->status, cqe->result))
>> +			nvme_complete_rq(rq);
>> +	}
>>  	queue->nr_cqe++;
>>  
>>  	return 0;
>> @@ -859,9 +955,18 @@ static int nvme_tcp_recv_pdu(struct nvme_tcp_queue *queue, struct sk_buff *skb,
>>  static inline void nvme_tcp_end_request(struct request *rq, u16 status)
>>  {
>>  	union nvme_result res = {};
>> +	struct nvme_tcp_request *req = blk_mq_rq_to_pdu(rq);
>> +	struct nvme_tcp_queue *queue = req->queue;
>> +	struct nvme_tcp_data_pdu *pdu = (void *)queue->pdu;
>>  
>> -	if (!nvme_try_complete_req(rq, cpu_to_le16(status << 1), res))
>> -		nvme_complete_rq(rq);
>> +	if (req->offloaded) {
>> +		req->status = cpu_to_le16(status << 1);
>> +		req->result = res;
>> +		nvme_tcp_teardown_ddp(queue, pdu->command_id, rq);
>> +	} else {
>> +		if (!nvme_try_complete_req(rq, cpu_to_le16(status << 1), res))
>> +			nvme_complete_rq(rq);
>> +	}
>>  }
>>  
>>  static int nvme_tcp_recv_data(struct nvme_tcp_queue *queue, struct sk_buff *skb,
> 
> 
> The req->offload checks assume the offload is to the expected
> offload_netdev, but you do not verify the data arrived as expected. You
> might get lucky if both netdev's belong to the same PCI device (assuming
> the h/w handles it a certain way), but it will not if the netdev's
> belong to different devices.
> 
> Consider a system with 2 network cards -- even if it is 2 mlx5 based
> devices. One setup can have the system using a bond with 1 port from
> each PCI device. The tx path picks a leg based on the hash of the ntuple
> and that (with Tariq's bond patches) becomes the expected offload
> device. A similar example holds for a pure routing setup with ECMP. For
> both there is full redundancy in the network - separate NIC cards
> connected to separate TORs to have independent network paths.
> 
> A packet arrives on the *other* netdevice - you have *no* control over
> the Rx path. Your current checks will think the packet arrived with DDP
> but it did not.
> 

There's no problem if another (non-offload) netdevice receives traffic
that arrives here. Because that other device will never set the SKB
frag pages to point to the final destination buffers, and so copy
offload will not take place.

The req->offload indication is mainly for matching ddp_setup with
ddp_teardown calls, it does not control copy/crc offload as these are
controlled per-skb using frags for copy and skb bits for crc.

Re: [PATCH v2 net-next 19/21] net/mlx5e: NVMEoTCP, data-path for DDP offload

[Boris Pismenny]

On 19/01/2021 6:36, David Ahern wrote:
> On 1/17/21 1:42 AM, Boris Pismenny wrote:
>> This is needed for a few reasons that are explained in detail
>> in the tcp-ddp offload documentation. See patch 21 overview
>> and rx-data-path sections. Our reasons are as follows:
> 
> I read the documentation patch, and it does not explain it and really
> should not since this is very mlx specific based on the changes.
> Different h/w will have different limitations. Given that, it would be
> best to enhance the patch description to explain why these gymnastics
> are needed for the skb.
> 

The text in the documentation that describes this trade-off:
''We remark that a single TCP packet may have numerous PDUs embedded
inside. NICs can choose to offload one or more of these PDUs according
to various trade-offs. Possibly, offloading such small PDUs is of little
value, and it is better to leave it to software. ``

Indeed, different HW may have other additional trade-offs. But, I
suspect that this one will be important for all.

>> 1) Each SKB may contain multiple PDUs. DDP offload doesn't operate on
>> PDU headers, so these are written in the receive ring. Therefore, we
>> need to rebuild the SKB to account for it. Additionally, due to HW
>> limitations, we will only offload the first PDU in the SKB.
> 
> Are you referring to LRO skbs here? I can't imagine going through this
> for 1500 byte packets that have multiple PDUs.
> 
> 

No, that is true for any skb, and non-LRO skbs in particular. Most SKBs
do not contain multiple PDUs, but the ones that do are handled
gracefully in this function.

Re: [PATCH v2 net-next 02/21] net: Introduce direct data placement tcp offload

[Boris Pismenny]

On 14/01/2021 22:43, Eric Dumazet wrote:
> On Thu, Jan 14, 2021 at 9:19 PM Boris Pismenny <borispismenny@gmail.com> wrote:
>>
>>
>>
>> On 14/01/2021 17:57, Eric Dumazet wrote:
>>> On Thu, Jan 14, 2021 at 4:10 PM Boris Pismenny <borisp@mellanox.com> wrote:
>>>>
>>>> This commit introduces direct data placement offload for TCP.
>>>> This capability is accompanied by new net_device operations that
>>>> configure hardware contexts. There is a context per socket, and a context per DDP
>>>> opreation. Additionally, a resynchronization routine is used to assist
>>>> hardware handle TCP OOO, and continue the offload.
>>>> Furthermore, we let the offloading driver advertise what is the max hw
>>>> sectors/segments.
>>>>
>>>> Using this interface, the NIC hardware will scatter TCP payload directly
>>>> to the BIO pages according to the command_id.
>>>> To maintain the correctness of the network stack, the driver is expected
>>>> to construct SKBs that point to the BIO pages.
>>>>
>>>> This, the SKB represents the data on the wire, while it is pointing
>>>> to data that is already placed in the destination buffer.
>>>> As a result, data from page frags should not be copied out to
>>>> the linear part.
>>>>
>>>> As SKBs that use DDP are already very memory efficient, we modify
>>>> skb_condence to avoid copying data from fragments to the linear
>>>> part of SKBs that belong to a socket that uses DDP offload.
>>>>
>>>> A follow-up patch will use this interface for DDP in NVMe-TCP.
>>>>
>>>> Signed-off-by: Boris Pismenny <borisp@mellanox.com>
>>>> Signed-off-by: Ben Ben-Ishay <benishay@mellanox.com>
>>>> Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
>>>> Signed-off-by: Yoray Zack <yorayz@mellanox.com>
>>>> ---
>>>>  include/linux/netdev_features.h    |   2 +
>>>>  include/linux/netdevice.h          |   5 ++
>>>>  include/net/inet_connection_sock.h |   4 +
>>>>  include/net/tcp_ddp.h              | 136 +++++++++++++++++++++++++++++
>>>>  net/Kconfig                        |   9 ++
>>>>  net/core/skbuff.c                  |   9 +-
>>>>  net/ethtool/common.c               |   1 +
>>>>  7 files changed, 165 insertions(+), 1 deletion(-)
>>>>  create mode 100644 include/net/tcp_ddp.h
>>>>
>>>> diff --git a/include/linux/netdev_features.h b/include/linux/netdev_features.h
>>>> index 934de56644e7..fb35dcac03d2 100644
>>>> --- a/include/linux/netdev_features.h
>>>> +++ b/include/linux/netdev_features.h
>>>> @@ -84,6 +84,7 @@ enum {
>>>>         NETIF_F_GRO_FRAGLIST_BIT,       /* Fraglist GRO */
>>>>
>>>>         NETIF_F_HW_MACSEC_BIT,          /* Offload MACsec operations */
>>>> +       NETIF_F_HW_TCP_DDP_BIT,         /* TCP direct data placement offload */
>>>>
>>>>         /*
>>>>          * Add your fresh new feature above and remember to update
>>>> @@ -157,6 +158,7 @@ enum {
>>>>  #define NETIF_F_GRO_FRAGLIST   __NETIF_F(GRO_FRAGLIST)
>>>>  #define NETIF_F_GSO_FRAGLIST   __NETIF_F(GSO_FRAGLIST)
>>>>  #define NETIF_F_HW_MACSEC      __NETIF_F(HW_MACSEC)
>>>> +#define NETIF_F_HW_TCP_DDP     __NETIF_F(HW_TCP_DDP)
>>>>
>>>>  /* Finds the next feature with the highest number of the range of start till 0.
>>>>   */
>>>> diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
>>>> index 259be67644e3..3dd3cdf5dec3 100644
>>>> --- a/include/linux/netdevice.h
>>>> +++ b/include/linux/netdevice.h
>>>> @@ -941,6 +941,7 @@ struct dev_ifalias {
>>>>
>>>>  struct devlink;
>>>>  struct tlsdev_ops;
>>>> +struct tcp_ddp_dev_ops;
>>>>
>>>>  struct netdev_name_node {
>>>>         struct hlist_node hlist;
>>>> @@ -1937,6 +1938,10 @@ struct net_device {
>>>>         const struct tlsdev_ops *tlsdev_ops;
>>>>  #endif
>>>>
>>>> +#ifdef CONFIG_TCP_DDP
>>>> +       const struct tcp_ddp_dev_ops *tcp_ddp_ops;
>>>> +#endif
>>>> +
>>>>         const struct header_ops *header_ops;
>>>>
>>>>         unsigned int            flags;
>>>> diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connection_sock.h
>>>> index 7338b3865a2a..a08b85b53aa8 100644
>>>> --- a/include/net/inet_connection_sock.h
>>>> +++ b/include/net/inet_connection_sock.h
>>>> @@ -66,6 +66,8 @@ struct inet_connection_sock_af_ops {
>>>>   * @icsk_ulp_ops          Pluggable ULP control hook
>>>>   * @icsk_ulp_data         ULP private data
>>>>   * @icsk_clean_acked      Clean acked data hook
>>>> + * @icsk_ulp_ddp_ops      Pluggable ULP direct data placement control hook
>>>> + * @icsk_ulp_ddp_data     ULP direct data placement private data
>>>>   * @icsk_listen_portaddr_node  hash to the portaddr listener hashtable
>>>>   * @icsk_ca_state:        Congestion control state
>>>>   * @icsk_retransmits:     Number of unrecovered [RTO] timeouts
>>>> @@ -94,6 +96,8 @@ struct inet_connection_sock {
>>>>         const struct tcp_ulp_ops  *icsk_ulp_ops;
>>>>         void __rcu                *icsk_ulp_data;
>>>>         void (*icsk_clean_acked)(struct sock *sk, u32 acked_seq);
>>>
>>> #ifdef CONFIG_TCP_DDP ?
>>>
>>>> +       const struct tcp_ddp_ulp_ops  *icsk_ulp_ddp_ops;
>>>> +       void __rcu                *icsk_ulp_ddp_data;
>>>>         struct hlist_node         icsk_listen_portaddr_node;
>>>>         unsigned int              (*icsk_sync_mss)(struct sock *sk, u32 pmtu);
>>>>         __u8                      icsk_ca_state:5,
>>>> diff --git a/include/net/tcp_ddp.h b/include/net/tcp_ddp.h
>>>> new file mode 100644
>>>> index 000000000000..31e5b1a16d0f
>>>> --- /dev/null
>>>> +++ b/include/net/tcp_ddp.h
>>>> @@ -0,0 +1,136 @@
>>>> +/* SPDX-License-Identifier: GPL-2.0
>>>> + *
>>>> + * tcp_ddp.h
>>>> + *     Author: Boris Pismenny <borisp@mellanox.com>
>>>> + *     Copyright (C) 2021 Mellanox Technologies.
>>>> + */
>>>> +#ifndef _TCP_DDP_H
>>>> +#define _TCP_DDP_H
>>>> +
>>>> +#include <linux/netdevice.h>
>>>> +#include <net/inet_connection_sock.h>
>>>> +#include <net/sock.h>
>>>> +
>>>> +/* limits returned by the offload driver, zero means don't care */
>>>> +struct tcp_ddp_limits {
>>>> +       int      max_ddp_sgl_len;
>>>> +};
>>>> +
>>>> +enum tcp_ddp_type {
>>>> +       TCP_DDP_NVME = 1,
>>>> +};
>>>> +
>>>> +/**
>>>> + * struct tcp_ddp_config - Generic tcp ddp configuration: tcp ddp IO queue
>>>> + * config implementations must use this as the first member.
>>>> + * Add new instances of tcp_ddp_config below (nvme-tcp, etc.).
>>>> + */
>>>> +struct tcp_ddp_config {
>>>> +       enum tcp_ddp_type    type;
>>>> +       unsigned char        buf[];
>>>> +};
>>>> +
>>>> +/**
>>>> + * struct nvme_tcp_ddp_config - nvme tcp ddp configuration for an IO queue
>>>> + *
>>>> + * @pfv:        pdu version (e.g., NVME_TCP_PFV_1_0)
>>>> + * @cpda:       controller pdu data alignmend (dwords, 0's based)
>>>> + * @dgst:       digest types enabled.
>>>> + *              The netdev will offload crc if ddp_crc is supported.
>>>> + * @queue_size: number of nvme-tcp IO queue elements
>>>> + * @queue_id:   queue identifier
>>>> + * @cpu_io:     cpu core running the IO thread for this queue
>>>> + */
>>>> +struct nvme_tcp_ddp_config {
>>>> +       struct tcp_ddp_config   cfg;
>>>> +
>>>> +       u16                     pfv;
>>>> +       u8                      cpda;
>>>> +       u8                      dgst;
>>>> +       int                     queue_size;
>>>> +       int                     queue_id;
>>>> +       int                     io_cpu;
>>>> +};
>>>> +
>>>> +/**
>>>> + * struct tcp_ddp_io - tcp ddp configuration for an IO request.
>>>> + *
>>>> + * @command_id:  identifier on the wire associated with these buffers
>>>> + * @nents:       number of entries in the sg_table
>>>> + * @sg_table:    describing the buffers for this IO request
>>>> + * @first_sgl:   first SGL in sg_table
>>>> + */
>>>> +struct tcp_ddp_io {
>>>> +       u32                     command_id;
>>>> +       int                     nents;
>>>> +       struct sg_table         sg_table;
>>>> +       struct scatterlist      first_sgl[SG_CHUNK_SIZE];
>>>> +};
>>>> +
>>>> +/* struct tcp_ddp_dev_ops - operations used by an upper layer protocol to configure ddp offload
>>>> + *
>>>> + * @tcp_ddp_limits:    limit the number of scatter gather entries per IO.
>>>> + *                     the device driver can use this to limit the resources allocated per queue.
>>>> + * @tcp_ddp_sk_add:    add offload for the queue represennted by the socket+config pair.
>>>> + *                     this function is used to configure either copy, crc or both offloads.
>>>> + * @tcp_ddp_sk_del:    remove offload from the socket, and release any device related resources.
>>>> + * @tcp_ddp_setup:     request copy offload for buffers associated with a command_id in tcp_ddp_io.
>>>> + * @tcp_ddp_teardown:  release offload resources association between buffers and command_id in
>>>> + *                     tcp_ddp_io.
>>>> + * @tcp_ddp_resync:    respond to the driver's resync_request. Called only if resync is successful.
>>>> + */
>>>> +struct tcp_ddp_dev_ops {
>>>> +       int (*tcp_ddp_limits)(struct net_device *netdev,
>>>> +                             struct tcp_ddp_limits *limits);
>>>> +       int (*tcp_ddp_sk_add)(struct net_device *netdev,
>>>> +                             struct sock *sk,
>>>> +                             struct tcp_ddp_config *config);
>>>> +       void (*tcp_ddp_sk_del)(struct net_device *netdev,
>>>> +                              struct sock *sk);
>>>> +       int (*tcp_ddp_setup)(struct net_device *netdev,
>>>> +                            struct sock *sk,
>>>> +                            struct tcp_ddp_io *io);
>>>> +       int (*tcp_ddp_teardown)(struct net_device *netdev,
>>>> +                               struct sock *sk,
>>>> +                               struct tcp_ddp_io *io,
>>>> +                               void *ddp_ctx);
>>>> +       void (*tcp_ddp_resync)(struct net_device *netdev,
>>>> +                              struct sock *sk, u32 seq);
>>>> +};
>>>> +
>>>> +#define TCP_DDP_RESYNC_REQ BIT(0)
>>>> +
>>>> +/**
>>>> + * struct tcp_ddp_ulp_ops - Interface to register uppper layer Direct Data Placement (DDP) TCP offload
>>>> + */
>>>> +struct tcp_ddp_ulp_ops {
>>>> +       /* NIC requests ulp to indicate if @seq is the start of a message */
>>>> +       bool (*resync_request)(struct sock *sk, u32 seq, u32 flags);
>>>> +       /* NIC driver informs the ulp that ddp teardown is done - used for async completions*/
>>>> +       void (*ddp_teardown_done)(void *ddp_ctx);
>>>> +};
>>>> +
>>>> +/**
>>>> + * struct tcp_ddp_ctx - Generic tcp ddp context: device driver per queue contexts must
>>>> + * use this as the first member.
>>>> + */
>>>> +struct tcp_ddp_ctx {
>>>> +       enum tcp_ddp_type    type;
>>>> +       unsigned char        buf[];
>>>> +};
>>>> +
>>>> +static inline struct tcp_ddp_ctx *tcp_ddp_get_ctx(const struct sock *sk)
>>>> +{
>>>> +       struct inet_connection_sock *icsk = inet_csk(sk);
>>>> +
>>>> +       return (__force struct tcp_ddp_ctx *)icsk->icsk_ulp_ddp_data;
>>>> +}
>>>> +
>>>> +static inline void tcp_ddp_set_ctx(struct sock *sk, void *ctx)
>>>> +{
>>>> +       struct inet_connection_sock *icsk = inet_csk(sk);
>>>> +
>>>> +       rcu_assign_pointer(icsk->icsk_ulp_ddp_data, ctx);
>>>> +}
>>>> +
>>>> +#endif //_TCP_DDP_H
>>>> diff --git a/net/Kconfig b/net/Kconfig
>>>> index f4c32d982af6..3876861cdc90 100644
>>>> --- a/net/Kconfig
>>>> +++ b/net/Kconfig
>>>> @@ -457,6 +457,15 @@ config ETHTOOL_NETLINK
>>>>           netlink. It provides better extensibility and some new features,
>>>>           e.g. notification messages.
>>>>
>>>> +config TCP_DDP
>>>> +       bool "TCP direct data placement offload"
>>>> +       default n
>>>> +       help
>>>> +         Direct Data Placement (DDP) offload for TCP enables ULP, such as
>>>> +         NVMe-TCP/iSCSI, to request the NIC to place TCP payload data
>>>> +         of a command response directly into kernel pages.
>>>> +
>>>> +
>>>>  endif   # if NET
>>>>
>>>>  # Used by archs to tell that they support BPF JIT compiler plus which flavour.
>>>> diff --git a/net/core/skbuff.c b/net/core/skbuff.c
>>>> index f62cae3f75d8..791c1b6bc067 100644
>>>> --- a/net/core/skbuff.c
>>>> +++ b/net/core/skbuff.c
>>>> @@ -69,6 +69,7 @@
>>>>  #include <net/xfrm.h>
>>>>  #include <net/mpls.h>
>>>>  #include <net/mptcp.h>
>>>> +#include <net/tcp_ddp.h>
>>>>
>>>>  #include <linux/uaccess.h>
>>>>  #include <trace/events/skb.h>
>>>> @@ -6140,9 +6141,15 @@ EXPORT_SYMBOL(pskb_extract);
>>>>   */
>>>>  void skb_condense(struct sk_buff *skb)
>>>>  {
>>>> +       bool is_ddp = false;
>>>> +
>>>> +#ifdef CONFIG_TCP_DDP
>>>
>>> This looks strange to me : TCP should call this helper while skb->sk is NULL
>>>
>>> Are you sure this is not dead code ?
>>>
>>
>> Will verify again on Sunday. AFAICT, early demux sets skb->sk before this code
>> is called.
> 
> 
> First, early demux is optional.
> 
> Secondly, skb->sk is stolen in skb_steal_sock() if early demux was performed.
> 
> 
> Just to clarify, the purpose of this code is to avoid skb condensing
>> data that is already placed into destination buffers.
> 
> Then this has not been tested. This suggests this code could be
> removed, I doubt that your target traffic would ever be 'condensed'.
> 

Thanks for the feedback!

Some retrospective about this:
We originally used the skb->ddp_crc bit for this check, but later we
tried to avoid it so as to reduce our dependence on said skb bit.
Unfortunately, that later change wasn't tested thoroughly.

We'll post v3 patches that will use the skb->ddp_crc bit for this check.
After re-testing with the new v3 patch I'm confident it will work.

>>
>>>> +       is_ddp = skb->sk && inet_csk(skb->sk) &&
>>>> +                inet_csk(skb->sk)->icsk_ulp_ddp_data;
>>>> +#endif
>>>>         if (skb->data_len) {
>>>>                 if (skb->data_len > skb->end - skb->tail ||
>>>> -                   skb_cloned(skb))
>>>> +                   skb_cloned(skb) || is_ddp)
>>>>                         return;
>>>>
>>>>                 /* Nice, we can free page frag(s) right now */
>>>> diff --git a/net/ethtool/common.c b/net/ethtool/common.c
>>>> index 24036e3055a1..a2ff7a4a6bbf 100644
>>>> --- a/net/ethtool/common.c
>>>> +++ b/net/ethtool/common.c
>>>> @@ -68,6 +68,7 @@ const char netdev_features_strings[NETDEV_FEATURE_COUNT][ETH_GSTRING_LEN] = {
>>>>         [NETIF_F_HW_TLS_RX_BIT] =        "tls-hw-rx-offload",
>>>>         [NETIF_F_GRO_FRAGLIST_BIT] =     "rx-gro-list",
>>>>         [NETIF_F_HW_MACSEC_BIT] =        "macsec-hw-offload",
>>>> +       [NETIF_F_HW_TCP_DDP_BIT] =       "tcp-ddp-offload",
>>>>  };
>>>>
>>>>  const char
>>>> --
>>>> 2.24.1
>>>>