diff mbox series

[v12,09/26] nvme-tcp: RX DDGST offload

Message ID 20230712161513.134860-10-aaptel@nvidia.com (mailing list archive)
State RFC
Headers show
Series nvme-tcp receive offloads | expand

Checks

Context Check Description
netdev/tree_selection success Guessing tree name failed - patch did not apply, async

Commit Message

Aurelien Aptel July 12, 2023, 4:14 p.m. UTC 
From: Yoray Zack <yorayz@nvidia.com>

Enable rx side of DDGST offload when supported.

At the end of the capsule, check if all the skb bits are on, and if not
recalculate the DDGST in SW and check it.

Signed-off-by: Yoray Zack <yorayz@nvidia.com>
Signed-off-by: Boris Pismenny <borisp@nvidia.com>
Signed-off-by: Ben Ben-Ishay <benishay@nvidia.com>
Signed-off-by: Or Gerlitz <ogerlitz@nvidia.com>
Signed-off-by: Shai Malin <smalin@nvidia.com>
Signed-off-by: Aurelien Aptel <aaptel@nvidia.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
---
 drivers/nvme/host/tcp.c | 120 +++++++++++++++++++++++++++++++++++++---
 1 file changed, 112 insertions(+), 8 deletions(-)

Comments

Sagi Grimberg Aug. 9, 2023, 7:59 a.m. UTC | #1 
On 7/12/23 19:14, Aurelien Aptel wrote:
> From: Yoray Zack <yorayz@nvidia.com>
> 
> Enable rx side of DDGST offload when supported.
> 
> At the end of the capsule, check if all the skb bits are on, and if not
> recalculate the DDGST in SW and check it.
> 
> Signed-off-by: Yoray Zack <yorayz@nvidia.com>
> Signed-off-by: Boris Pismenny <borisp@nvidia.com>
> Signed-off-by: Ben Ben-Ishay <benishay@nvidia.com>
> Signed-off-by: Or Gerlitz <ogerlitz@nvidia.com>
> Signed-off-by: Shai Malin <smalin@nvidia.com>
> Signed-off-by: Aurelien Aptel <aaptel@nvidia.com>
> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
> ---
>   drivers/nvme/host/tcp.c | 120 +++++++++++++++++++++++++++++++++++++---
>   1 file changed, 112 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
> index 6057cd424a19..df58668cbad6 100644
> --- a/drivers/nvme/host/tcp.c
> +++ b/drivers/nvme/host/tcp.c
> @@ -130,6 +130,7 @@ 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 {
> @@ -168,6 +169,7 @@ struct nvme_tcp_queue {
>   	 */
>   	atomic64_t		resync_req;
>   	struct ulp_ddp_limits	ddp_limits;
> +	bool			ddp_ddgst_valid;
>   #endif
>   
>   	/* send state */
> @@ -358,9 +360,29 @@ static inline bool is_netdev_ulp_offload_active(struct net_device *netdev,
>   	if (test_bit(ULP_DDP_C_NVME_TCP_BIT, netdev->ulp_ddp_caps.active))
>   		return true;
>   
> +	/*
> +	 * Otherwise, if netdev supports nvme-tcp ddgst offload and it
> +	 * was enabled, we can offload
> +	 */
> +	if (queue->data_digest && test_bit(ULP_DDP_C_NVME_TCP_DDGST_RX_BIT,
> +					   netdev->ulp_ddp_caps.active))
> +		return true;
> +
>   	return false;
>   }
>   
> +static inline bool nvme_tcp_ddp_ddgst_ok(struct nvme_tcp_queue *queue)
> +{
> +	return queue->ddp_ddgst_valid;
> +}
> +
> +static inline void nvme_tcp_ddp_ddgst_update(struct nvme_tcp_queue *queue,
> +					     struct sk_buff *skb)
> +{
> +	if (queue->ddp_ddgst_valid)
> +		queue->ddp_ddgst_valid = skb_is_ulp_crc(skb);
> +}
> +
>   static int nvme_tcp_req_map_ddp_sg(struct nvme_tcp_request *req, struct request *rq)
>   {
>   	int ret;
> @@ -375,6 +397,38 @@ static int nvme_tcp_req_map_ddp_sg(struct nvme_tcp_request *req, struct request
>   	return 0;
>   }
>   
> +static void nvme_tcp_ddp_ddgst_recalc(struct ahash_request *hash,
> +				      struct request *rq,
> +				      __le32 *ddgst)
> +{
> +	struct nvme_tcp_request *req;
> +
> +	if (!rq)
> +		return;
> +
> +	req = blk_mq_rq_to_pdu(rq);
> +
> +	if (!req->offloaded) {
> +		/* if we have DDGST_RX offload without DDP the request
> +		 * wasn't mapped, so we need to map it here
> +		 */
> +		if (nvme_tcp_req_map_ddp_sg(req, rq))
> +			return;

grr.. wondering if this is something we want to support (crc without
ddp).

> +	}
> +
> +	req->ddp.sg_table.sgl = req->ddp.first_sgl;

Why is this assignment needed? why not pass req->ddp.first_sgl ?

> +	ahash_request_set_crypt(hash, req->ddp.sg_table.sgl, (u8 *)ddgst,
> +				req->data_len);
> +	crypto_ahash_digest(hash);
> +
> +	if (!req->offloaded) {
> +		/* without DDP, ddp_teardown() won't be called, so
> +		 * free the table here
> +		 */
> +		sg_free_table_chained(&req->ddp.sg_table, SG_CHUNK_SIZE);
> +	}
> +}
> +
>   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 ulp_ddp_ulp_ops nvme_tcp_ddp_ulp_ops = {
> @@ -434,6 +488,10 @@ static int nvme_tcp_offload_socket(struct nvme_tcp_queue *queue)
>   {
>   	struct net_device *netdev = queue->ctrl->offloading_netdev;
>   	struct ulp_ddp_config config = {.type = ULP_DDP_NVME};
> +	bool offload_ddp = test_bit(ULP_DDP_C_NVME_TCP_BIT,
> +				    netdev->ulp_ddp_caps.active);
> +	bool offload_ddgst_rx = test_bit(ULP_DDP_C_NVME_TCP_DDGST_RX_BIT,
> +					 netdev->ulp_ddp_caps.active);
>   	int ret;
>   
>   	config.nvmeotcp.pfv = NVME_TCP_PFV_1_0;
> @@ -460,7 +518,10 @@ static int nvme_tcp_offload_socket(struct nvme_tcp_queue *queue)
>   	}
>   
>   	inet_csk(queue->sock->sk)->icsk_ulp_ddp_ops = &nvme_tcp_ddp_ulp_ops;
> -	set_bit(NVME_TCP_Q_OFF_DDP, &queue->flags);
> +	if (offload_ddp)
> +		set_bit(NVME_TCP_Q_OFF_DDP, &queue->flags);
> +	if (queue->data_digest && offload_ddgst_rx)
> +		set_bit(NVME_TCP_Q_OFF_DDGST_RX, &queue->flags);
>   	return 0;
>   }
>   
> @@ -474,6 +535,7 @@ static void nvme_tcp_unoffload_socket(struct nvme_tcp_queue *queue)
>   	}
>   
>   	clear_bit(NVME_TCP_Q_OFF_DDP, &queue->flags);
> +	clear_bit(NVME_TCP_Q_OFF_DDGST_RX, &queue->flags);
>   
>   	netdev->netdev_ops->ulp_ddp_ops->sk_del(netdev, queue->sock->sk);
>   
> @@ -562,6 +624,20 @@ static inline bool is_netdev_ulp_offload_active(struct net_device *netdev,
>   	return false;
>   }
>   
> +static inline bool nvme_tcp_ddp_ddgst_ok(struct nvme_tcp_queue *queue)
> +{
> +	return false;
> +}
> +
> +static inline void nvme_tcp_ddp_ddgst_update(struct nvme_tcp_queue *queue,
> +					     struct sk_buff *skb)
> +{}
> +
> +static void nvme_tcp_ddp_ddgst_recalc(struct ahash_request *hash,
> +				      struct request *rq,
> +				      __le32 *ddgst)
> +{}
> +
>   static int nvme_tcp_setup_ddp(struct nvme_tcp_queue *queue, u16 command_id,
>   			      struct request *rq)
>   {
> @@ -844,6 +920,9 @@ static void nvme_tcp_init_recv_ctx(struct nvme_tcp_queue *queue)
>   	queue->pdu_offset = 0;
>   	queue->data_remaining = -1;
>   	queue->ddgst_remaining = 0;
> +#ifdef CONFIG_ULP_DDP
> +	queue->ddp_ddgst_valid = true;
> +#endif
>   }
>   
>   static void nvme_tcp_error_recovery(struct nvme_ctrl *ctrl)
> @@ -1047,7 +1126,8 @@ 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;
>   
> -	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))

This now becomes two atomic bitops to check for each capability, where
its more likely that neighther are on...

Is this really racing with anything? maybe just check with bitwise AND?
or a local variable (or struct member)
I don't think that we should add any more overhead for the normal path
than we already have.

>   		nvme_tcp_resync_response(queue, skb, *offset);
>   
>   	ret = skb_copy_bits(skb, *offset,
> @@ -1111,6 +1191,10 @@ static int nvme_tcp_recv_data(struct nvme_tcp_queue *queue, struct sk_buff *skb,
>   		nvme_cid_to_rq(nvme_tcp_tagset(queue), pdu->command_id);
>   	struct nvme_tcp_request *req = blk_mq_rq_to_pdu(rq);
>   
> +	if (queue->data_digest &&
> +	    test_bit(NVME_TCP_Q_OFF_DDGST_RX, &queue->flags))

And a third atomic bitop..

> +		nvme_tcp_ddp_ddgst_update(queue, skb);
> +
>   	while (true) {
>   		int recv_len, ret;
>   
> @@ -1139,7 +1223,8 @@ 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)
> +		if (queue->data_digest &&
> +		    !test_bit(NVME_TCP_Q_OFF_DDGST_RX, &queue->flags))

and a 4'th atomic bitop...

>   			ret = skb_copy_and_hash_datagram_iter(skb, *offset,
>   				&req->iter, recv_len, queue->rcv_hash);
>   		else
> @@ -1181,8 +1266,11 @@ 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;
> +	struct request *rq;
>   	int ret;
>   
> +	if (test_bit(NVME_TCP_Q_OFF_DDGST_RX, &queue->flags))
> +		nvme_tcp_ddp_ddgst_update(queue, skb);

and a 5'th atomic bitop...

>   	ret = skb_copy_bits(skb, *offset, &ddgst[off], recv_len);
>   	if (unlikely(ret))
>   		return ret;
> @@ -1193,9 +1281,25 @@ static int nvme_tcp_recv_ddgst(struct nvme_tcp_queue *queue,
>   	if (queue->ddgst_remaining)
>   		return 0;
>   
> +	rq = nvme_cid_to_rq(nvme_tcp_tagset(queue),
> +			    pdu->command_id);
> +
> +	if (test_bit(NVME_TCP_Q_OFF_DDGST_RX, &queue->flags)) {

and a 6'th... ok this is just spraying atomic bitops on the data
path. Please find a better solution to this.

> +		/*
> +		 * If HW successfully offloaded the digest
> +		 * verification, we can skip it
> +		 */
> +		if (nvme_tcp_ddp_ddgst_ok(queue))
> +			goto out;
> +		/*
> +		 * Otherwise we have to recalculate and verify the
> +		 * digest with the software-fallback
> +		 */
> +		nvme_tcp_ddp_ddgst_recalc(queue->rcv_hash, rq,
> +					  &queue->exp_ddgst);
> +	}
> +
>   	if (queue->recv_ddgst != queue->exp_ddgst) {
> -		struct request *rq = nvme_cid_to_rq(nvme_tcp_tagset(queue),
> -					pdu->command_id);
>   		struct nvme_tcp_request *req = blk_mq_rq_to_pdu(rq);
>   
>   		req->status = cpu_to_le16(NVME_SC_DATA_XFER_ERROR);
> @@ -1206,9 +1310,8 @@ static int nvme_tcp_recv_ddgst(struct nvme_tcp_queue *queue,
>   			le32_to_cpu(queue->exp_ddgst));
>   	}
>   
> +out:
>   	if (pdu->hdr.flags & NVME_TCP_F_DATA_SUCCESS) {
> -		struct request *rq = nvme_cid_to_rq(nvme_tcp_tagset(queue),
> -					pdu->command_id);
>   		struct nvme_tcp_request *req = blk_mq_rq_to_pdu(rq);
>   
>   		nvme_tcp_end_request(rq, le16_to_cpu(req->status));
> @@ -2125,7 +2228,8 @@ static void __nvme_tcp_stop_queue(struct nvme_tcp_queue *queue)
>   	kernel_sock_shutdown(queue->sock, SHUT_RDWR);
>   	nvme_tcp_restore_sock_ops(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);
>   }
>
Aurelien Aptel Aug. 10, 2023, 2:48 p.m. UTC | #2 
Sagi Grimberg <sagi@grimberg.me> writes:
> grr.. wondering if this is something we want to support (crc without
> ddp).

We agree, we don't want to support it. We will remove it and check it
doesn't happen in is_netdev_offload_active().

>> +     req->ddp.sg_table.sgl = req->ddp.first_sgl;
> Why is this assignment needed? why not pass req->ddp.first_sgl ?

Correct, this assignment is not needed we will remove it.

>>   static void nvme_tcp_error_recovery(struct nvme_ctrl *ctrl)
>> @@ -1047,7 +1126,8 @@ 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;
>>
>> -     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))
>
> This now becomes two atomic bitops to check for each capability, where
> its more likely that neighther are on...
>
> Is this really racing with anything? maybe just check with bitwise AND?
> or a local variable (or struct member)
> I don't think that we should add any more overhead for the normal path
> than we already have.

Are you sure test_bit() is atomic? The underlying definitions seems
non-atomic (constant_test_bit or const_test_bit), are we missing
anything?

We were also following a similar implementation to NVME_TCP_Q_POLLING
which was using test_bit(). Should we move to a regular bool flag like
queue->data_digest?

>> +     if (queue->data_digest &&
>> +         test_bit(NVME_TCP_Q_OFF_DDGST_RX, &queue->flags))
>
> And a third atomic bitop..

See above

>> +                 !test_bit(NVME_TCP_Q_OFF_DDGST_RX, &queue->flags))
> and a 4'th atomic bitop...

See above

>> +     if (test_bit(NVME_TCP_Q_OFF_DDGST_RX, &queue->flags))
>> +             nvme_tcp_ddp_ddgst_update(queue, skb);
>
> and a 5'th atomic bitop...

See above

>> +     if (test_bit(NVME_TCP_Q_OFF_DDGST_RX, &queue->flags)) {
> and a 6'th... ok this is just spraying atomic bitops on the data
> path. Please find a better solution to this.

See above

Thanks
Sagi Grimberg Aug. 13, 2023, 1:49 p.m. UTC | #3 
On 8/10/23 17:48, Aurelien Aptel wrote:
> Sagi Grimberg <sagi@grimberg.me> writes:
>> grr.. wondering if this is something we want to support (crc without
>> ddp).
> 
> We agree, we don't want to support it. We will remove it and check it
> doesn't happen in is_netdev_offload_active().
> 
>>> +     req->ddp.sg_table.sgl = req->ddp.first_sgl;
>> Why is this assignment needed? why not pass req->ddp.first_sgl ?
> 
> Correct, this assignment is not needed we will remove it.
> 
>>>    static void nvme_tcp_error_recovery(struct nvme_ctrl *ctrl)
>>> @@ -1047,7 +1126,8 @@ 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;
>>>
>>> -     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))
>>
>> This now becomes two atomic bitops to check for each capability, where
>> its more likely that neighther are on...
>>
>> Is this really racing with anything? maybe just check with bitwise AND?
>> or a local variable (or struct member)
>> I don't think that we should add any more overhead for the normal path
>> than we already have.
> 
> Are you sure test_bit() is atomic? The underlying definitions seems
> non-atomic (constant_test_bit or const_test_bit), are we missing
> anything?

Hmm, no you're right.

This makes me wonder if we have some places to convert test_bit to
test_bit_acquire where we must not make forward progress.

This particular condition is fine I think...
diff mbox series

Patch

diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index 6057cd424a19..df58668cbad6 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -130,6 +130,7 @@  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 {
@@ -168,6 +169,7 @@  struct nvme_tcp_queue {
 	 */
 	atomic64_t		resync_req;
 	struct ulp_ddp_limits	ddp_limits;
+	bool			ddp_ddgst_valid;
 #endif
 
 	/* send state */
@@ -358,9 +360,29 @@  static inline bool is_netdev_ulp_offload_active(struct net_device *netdev,
 	if (test_bit(ULP_DDP_C_NVME_TCP_BIT, netdev->ulp_ddp_caps.active))
 		return true;
 
+	/*
+	 * Otherwise, if netdev supports nvme-tcp ddgst offload and it
+	 * was enabled, we can offload
+	 */
+	if (queue->data_digest && test_bit(ULP_DDP_C_NVME_TCP_DDGST_RX_BIT,
+					   netdev->ulp_ddp_caps.active))
+		return true;
+
 	return false;
 }
 
+static inline bool nvme_tcp_ddp_ddgst_ok(struct nvme_tcp_queue *queue)
+{
+	return queue->ddp_ddgst_valid;
+}
+
+static inline void nvme_tcp_ddp_ddgst_update(struct nvme_tcp_queue *queue,
+					     struct sk_buff *skb)
+{
+	if (queue->ddp_ddgst_valid)
+		queue->ddp_ddgst_valid = skb_is_ulp_crc(skb);
+}
+
 static int nvme_tcp_req_map_ddp_sg(struct nvme_tcp_request *req, struct request *rq)
 {
 	int ret;
@@ -375,6 +397,38 @@  static int nvme_tcp_req_map_ddp_sg(struct nvme_tcp_request *req, struct request
 	return 0;
 }
 
+static void nvme_tcp_ddp_ddgst_recalc(struct ahash_request *hash,
+				      struct request *rq,
+				      __le32 *ddgst)
+{
+	struct nvme_tcp_request *req;
+
+	if (!rq)
+		return;
+
+	req = blk_mq_rq_to_pdu(rq);
+
+	if (!req->offloaded) {
+		/* if we have DDGST_RX offload without DDP the request
+		 * wasn't mapped, so we need to map it here
+		 */
+		if (nvme_tcp_req_map_ddp_sg(req, rq))
+			return;
+	}
+
+	req->ddp.sg_table.sgl = req->ddp.first_sgl;
+	ahash_request_set_crypt(hash, req->ddp.sg_table.sgl, (u8 *)ddgst,
+				req->data_len);
+	crypto_ahash_digest(hash);
+
+	if (!req->offloaded) {
+		/* without DDP, ddp_teardown() won't be called, so
+		 * free the table here
+		 */
+		sg_free_table_chained(&req->ddp.sg_table, SG_CHUNK_SIZE);
+	}
+}
+
 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 ulp_ddp_ulp_ops nvme_tcp_ddp_ulp_ops = {
@@ -434,6 +488,10 @@  static int nvme_tcp_offload_socket(struct nvme_tcp_queue *queue)
 {
 	struct net_device *netdev = queue->ctrl->offloading_netdev;
 	struct ulp_ddp_config config = {.type = ULP_DDP_NVME};
+	bool offload_ddp = test_bit(ULP_DDP_C_NVME_TCP_BIT,
+				    netdev->ulp_ddp_caps.active);
+	bool offload_ddgst_rx = test_bit(ULP_DDP_C_NVME_TCP_DDGST_RX_BIT,
+					 netdev->ulp_ddp_caps.active);
 	int ret;
 
 	config.nvmeotcp.pfv = NVME_TCP_PFV_1_0;
@@ -460,7 +518,10 @@  static int nvme_tcp_offload_socket(struct nvme_tcp_queue *queue)
 	}
 
 	inet_csk(queue->sock->sk)->icsk_ulp_ddp_ops = &nvme_tcp_ddp_ulp_ops;
-	set_bit(NVME_TCP_Q_OFF_DDP, &queue->flags);
+	if (offload_ddp)
+		set_bit(NVME_TCP_Q_OFF_DDP, &queue->flags);
+	if (queue->data_digest && offload_ddgst_rx)
+		set_bit(NVME_TCP_Q_OFF_DDGST_RX, &queue->flags);
 	return 0;
 }
 
@@ -474,6 +535,7 @@  static void nvme_tcp_unoffload_socket(struct nvme_tcp_queue *queue)
 	}
 
 	clear_bit(NVME_TCP_Q_OFF_DDP, &queue->flags);
+	clear_bit(NVME_TCP_Q_OFF_DDGST_RX, &queue->flags);
 
 	netdev->netdev_ops->ulp_ddp_ops->sk_del(netdev, queue->sock->sk);
 
@@ -562,6 +624,20 @@  static inline bool is_netdev_ulp_offload_active(struct net_device *netdev,
 	return false;
 }
 
+static inline bool nvme_tcp_ddp_ddgst_ok(struct nvme_tcp_queue *queue)
+{
+	return false;
+}
+
+static inline void nvme_tcp_ddp_ddgst_update(struct nvme_tcp_queue *queue,
+					     struct sk_buff *skb)
+{}
+
+static void nvme_tcp_ddp_ddgst_recalc(struct ahash_request *hash,
+				      struct request *rq,
+				      __le32 *ddgst)
+{}
+
 static int nvme_tcp_setup_ddp(struct nvme_tcp_queue *queue, u16 command_id,
 			      struct request *rq)
 {
@@ -844,6 +920,9 @@  static void nvme_tcp_init_recv_ctx(struct nvme_tcp_queue *queue)
 	queue->pdu_offset = 0;
 	queue->data_remaining = -1;
 	queue->ddgst_remaining = 0;
+#ifdef CONFIG_ULP_DDP
+	queue->ddp_ddgst_valid = true;
+#endif
 }
 
 static void nvme_tcp_error_recovery(struct nvme_ctrl *ctrl)
@@ -1047,7 +1126,8 @@  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;
 
-	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, skb, *offset);
 
 	ret = skb_copy_bits(skb, *offset,
@@ -1111,6 +1191,10 @@  static int nvme_tcp_recv_data(struct nvme_tcp_queue *queue, struct sk_buff *skb,
 		nvme_cid_to_rq(nvme_tcp_tagset(queue), pdu->command_id);
 	struct nvme_tcp_request *req = blk_mq_rq_to_pdu(rq);
 
+	if (queue->data_digest &&
+	    test_bit(NVME_TCP_Q_OFF_DDGST_RX, &queue->flags))
+		nvme_tcp_ddp_ddgst_update(queue, skb);
+
 	while (true) {
 		int recv_len, ret;
 
@@ -1139,7 +1223,8 @@  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)
+		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
@@ -1181,8 +1266,11 @@  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;
+	struct request *rq;
 	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;
@@ -1193,9 +1281,25 @@  static int nvme_tcp_recv_ddgst(struct nvme_tcp_queue *queue,
 	if (queue->ddgst_remaining)
 		return 0;
 
+	rq = nvme_cid_to_rq(nvme_tcp_tagset(queue),
+			    pdu->command_id);
+
+	if (test_bit(NVME_TCP_Q_OFF_DDGST_RX, &queue->flags)) {
+		/*
+		 * If HW successfully offloaded the digest
+		 * verification, we can skip it
+		 */
+		if (nvme_tcp_ddp_ddgst_ok(queue))
+			goto out;
+		/*
+		 * Otherwise we have to recalculate and verify the
+		 * digest with the software-fallback
+		 */
+		nvme_tcp_ddp_ddgst_recalc(queue->rcv_hash, rq,
+					  &queue->exp_ddgst);
+	}
+
 	if (queue->recv_ddgst != queue->exp_ddgst) {
-		struct request *rq = nvme_cid_to_rq(nvme_tcp_tagset(queue),
-					pdu->command_id);
 		struct nvme_tcp_request *req = blk_mq_rq_to_pdu(rq);
 
 		req->status = cpu_to_le16(NVME_SC_DATA_XFER_ERROR);
@@ -1206,9 +1310,8 @@  static int nvme_tcp_recv_ddgst(struct nvme_tcp_queue *queue,
 			le32_to_cpu(queue->exp_ddgst));
 	}
 
+out:
 	if (pdu->hdr.flags & NVME_TCP_F_DATA_SUCCESS) {
-		struct request *rq = nvme_cid_to_rq(nvme_tcp_tagset(queue),
-					pdu->command_id);
 		struct nvme_tcp_request *req = blk_mq_rq_to_pdu(rq);
 
 		nvme_tcp_end_request(rq, le16_to_cpu(req->status));
@@ -2125,7 +2228,8 @@  static void __nvme_tcp_stop_queue(struct nvme_tcp_queue *queue)
 	kernel_sock_shutdown(queue->sock, SHUT_RDWR);
 	nvme_tcp_restore_sock_ops(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);
 }