From: Boris Pismenny <borispismenny@gmail.com>
To: Shai Malin <smalin@marvell.com>,
"linux-nvme@lists.infradead.org" <linux-nvme@lists.infradead.org>,
Sagi Grimberg <sagi@grimberg.me>,
Boris Pismenny <borisp@mellanox.com>,
"kuba@kernel.org" <kuba@kernel.org>,
"davem@davemloft.net" <davem@davemloft.net>,
"saeedm@nvidia.com" <saeedm@nvidia.com>,
"hch@lst.de" <hch@lst.de>, "axboe@fb.com" <axboe@fb.com>,
"kbusch@kernel.org" <kbusch@kernel.org>,
"viro@zeniv.linux.org.uk" <viro@zeniv.linux.org.uk>,
"edumazet@google.com" <edumazet@google.com>
Cc: Yoray Zack <yorayz@mellanox.com>,
Ariel Elior <aelior@marvell.com>,
Ben Ben-Ishay <benishay@mellanox.com>,
Michal Kalderon <mkalderon@marvell.com>,
"boris.pismenny@gmail.com" <boris.pismenny@gmail.com>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
Or Gerlitz <ogerlitz@mellanox.com>
Subject: Re: [PATCH net-next RFC v1 07/10] nvme-tcp : Recalculate crc in the end of the capsule
Date: Sun, 8 Nov 2020 09:28:04 +0200 [thread overview]
Message-ID: <5dcbb7b1-f1e2-f436-f211-8f4ef6712e52@gmail.com> (raw)
In-Reply-To: <PH0PR18MB3845FDA1C8E6063A03ECCE14CCEB0@PH0PR18MB3845.namprd18.prod.outlook.com>
On 08/11/2020 8:59, Shai Malin wrote:
> On 09/10/2020 1:44, Sagi Grimberg wrote:
>> On 9/30/20 7:20 PM, Boris Pismenny wrote:
>>
>>> 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.
>> Can you clarify in the patch description that this is only for pdu
>> data digest and not header digest?
>>
> Not a security expert, but according to my understanding, the NVMeTCP data digest is a layer 5 CRC, and as such it is expected to be end-to-end, meaning it is computed by layer 5 on the transmitter and verified on layer 5 on the receiver.
> Any data corruption which happens in any of the lower layers, including their software processing, should be protected by this CRC. For example, if the IP or TCP stack has a bug that corrupts the NVMeTCP payload data, the CRC should protect against it. It seems that may not be the case with this offload.
If the TCP/IP stack corrupts packet data, then likely many TCP/IP consumers will be effected, and it will be fixed promptly.
Unlike with TOE, these bugs can be easily fixed/hotpatched by the community.
>
>>> 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.
>> ??
>>
>> From my scan it doeesn't look like you do that.. Am I missing something?
>> Can you explain?
>>
>>> 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 | 66
>> ++++++++++++++++++++++++++++++++++++-----
>>> 1 file changed, 58 insertions(+), 8 deletions(-)
>>>
>>> diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c index
>>> 7bd97f856677..9a620d1dacb4 100644
>>> --- a/drivers/nvme/host/tcp.c
>>> +++ b/drivers/nvme/host/tcp.c
>>> @@ -94,6 +94,7 @@ struct nvme_tcp_queue {
>>> size_t data_remaining;
>>> size_t ddgst_remaining;
>>> unsigned int nr_cqe;
>>> + bool crc_valid;
> I suggest to rename it to ddgst_valid.
>
Sure
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next prev parent reply other threads:[~2020-11-08 7:28 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-30 16:20 [PATCH net-next RFC v1 00/10] nvme-tcp receive offloads Boris Pismenny
2020-09-30 16:20 ` [PATCH net-next RFC v1 01/10] iov_iter: Skip copy in memcpy_to_page if src==dst Boris Pismenny
2020-10-08 23:05 ` Sagi Grimberg
2020-09-30 16:20 ` [PATCH net-next RFC v1 02/10] net: Introduce direct data placement tcp offload Boris Pismenny
2020-10-08 21:47 ` Sagi Grimberg
2020-10-11 14:44 ` Boris Pismenny
2020-09-30 16:20 ` [PATCH net-next RFC v1 03/10] net: Introduce crc offload for tcp ddp ulp Boris Pismenny
2020-10-08 21:51 ` Sagi Grimberg
2020-10-11 14:58 ` Boris Pismenny
2020-09-30 16:20 ` [PATCH net-next RFC v1 04/10] net/tls: expose get_netdev_for_sock Boris Pismenny
2020-10-08 21:56 ` Sagi Grimberg
2020-09-30 16:20 ` [PATCH net-next RFC v1 05/10] nvme-tcp: Add DDP offload control path Boris Pismenny
2020-10-08 22:19 ` Sagi Grimberg
2020-10-19 18:28 ` Boris Pismenny
[not found] ` <PH0PR18MB3845430DDF572E0DD4832D06CCED0@PH0PR18MB3845.namprd18.prod.outlook.com>
2020-11-08 6:51 ` Shai Malin
2020-11-09 23:23 ` Sagi Grimberg
2020-11-11 5:12 ` FW: " Shai Malin
2020-11-11 5:43 ` Shai Malin
2020-09-30 16:20 ` [PATCH net-next RFC v1 06/10] nvme-tcp: Add DDP data-path Boris Pismenny
2020-10-08 22:29 ` Sagi Grimberg
2020-10-08 23:00 ` Sagi Grimberg
2020-11-08 13:59 ` Boris Pismenny
2020-11-08 9:44 ` Boris Pismenny
2020-11-09 23:18 ` Sagi Grimberg
2020-09-30 16:20 ` [PATCH net-next RFC v1 07/10] nvme-tcp : Recalculate crc in the end of the capsule Boris Pismenny
2020-10-08 22:44 ` Sagi Grimberg
[not found] ` <PH0PR18MB3845764B48FD24C87FA34304CCED0@PH0PR18MB3845.namprd18.prod.outlook.com>
[not found] ` <PH0PR18MB38458FD325BD77983D2623D4CCEB0@PH0PR18MB3845.namprd18.prod.outlook.com>
2020-11-08 6:59 ` Shai Malin
2020-11-08 7:28 ` Boris Pismenny [this message]
2020-11-08 14:46 ` Boris Pismenny
2020-09-30 16:20 ` [PATCH net-next RFC v1 08/10] nvme-tcp: Deal with netdevice DOWN events Boris Pismenny
2020-10-08 22:47 ` Sagi Grimberg
2020-10-11 6:54 ` Or Gerlitz
2020-09-30 16:20 ` [PATCH net-next RFC v1 09/10] net/mlx5e: Add NVMEoTCP offload Boris Pismenny
2020-09-30 16:20 ` [PATCH net-next RFC v1 10/10] net/mlx5e: NVMEoTCP, data-path for DDP offload Boris Pismenny
2020-10-09 0:08 ` [PATCH net-next RFC v1 00/10] nvme-tcp receive offloads Sagi Grimberg
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