From: Sagi Grimberg <sagi@grimberg.me>
To: Hannes Reinecke <hare@suse.de>, Chris Leech <cleech@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>, Keith Busch <kbusch@kernel.org>,
linux-nvme@lists.infradead.org, Chuck Lever <cel@kernel.org>,
kernel-tls-handshake@lists.linux.dev
Subject: Re: [PATCH 06/18] nvme-tcp: call 'queue->data_ready()' in nvme_tcp_data_ready()
Date: Wed, 22 Mar 2023 10:12:13 +0200 [thread overview]
Message-ID: <e55cf3ce-6446-7663-aaac-45d497714db7@grimberg.me> (raw)
In-Reply-To: <2dbd26ec-c384-866c-8d76-38364fa3330e@suse.de>
On 3/22/23 08:59, Hannes Reinecke wrote:
> On 3/22/23 01:18, Chris Leech wrote:
>> On Tue, Mar 21, 2023 at 03:09:06PM +0100, Hannes Reinecke wrote:
>>> On 3/21/23 14:44, Sagi Grimberg wrote:
>>>>
>>>>> Call the original data_ready() callback in nvme_tcp_data_ready()
>>>>> to avoid a receive stall.
>>>>
>>>> Can you please improve the description to include what is the stall?
>>>> For example, does the stall exist today? If it is, I would like to
>>>> separate such patches from this set and include them asap.
>>>>
>>> That is actually particular to the TLS implementation, as it uses the
>>> 'data_ready' callback to produce the data which can be read by eg
>>> recvmsg().
>>>
>>> Without this call there's no data to peruse for recvmsg().
>>>
>>> But I'm not _that_ deep into networking details to know whether this
>>> is TLS
>>> specific or an issue with any data_ready callback.
>>> I assume the latter, but then again, who knows.
>>>
>>> Hence the slightly vague description.
>>
>> This looks like the socket callbacks end up hooked in the wrong order.
>> Ideally it would be tcp -> tls -> nvme_tcp, while this currently looks
>> like tcp -> nvme_tcp and then this call back to tls for decryption.
>>
> Well, problem is that I need not one but two sets the callbacks.
> One callback is for waking up userspace (took me weeks to figure that
> out), and needs to added before calling the userspace helper.
> The other is the 'normal' nvme-tcp callback:
>
> tcp->nvme-upcall->tls->nvme-tcp
>
> So really the problem is not so much an inversion, but rather the fact
> that the nvme-upcall callback is really only needed for the duration
> of the handshake. And hence I thought that we should remove the callback
> once we're done with the upcall.
What do you mean remove the callback? data_ready? I'm not sure I'm
following.
> Turns out that we can't, and the best we can do is to disable the
> functionality, leaving the callback itself in place.
>
>> I'm not quite sure how to untangle this; nvme_tcp can't just set it's
>> own callbacks before initializing kTLS, becuse that's being done by
>> tlshd which is going to need the userspace socket API callbacks working.
>>
> Correct.
> So for now I'll leave the callbacks in place, even though they are
> pointless after the upcall.
Does it make any difference now that callbacks setting moved to
nvme_tcp_start_queue?
Again, I'm not sure I understand what callback is pointless?
next prev parent reply other threads:[~2023-03-22 8:12 UTC|newest]
Thread overview: 87+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-21 12:43 [RFC PATCH 00/18] nvme: In-kernel TLS support for TCP Hannes Reinecke
2023-03-21 12:43 ` [PATCH 01/18] nvme-keyring: register '.nvme' keyring Hannes Reinecke
2023-03-21 13:50 ` Sagi Grimberg
2023-03-21 14:11 ` Hannes Reinecke
2023-03-21 12:43 ` [PATCH 02/18] nvme-keyring: define a 'psk' keytype Hannes Reinecke
2023-03-22 8:29 ` Sagi Grimberg
2023-03-22 8:38 ` Hannes Reinecke
2023-03-22 8:49 ` Sagi Grimberg
2023-03-21 12:43 ` [PATCH 03/18] nvme: add TCP TSAS definitions Hannes Reinecke
2023-03-21 13:46 ` Sagi Grimberg
2023-03-21 12:43 ` [PATCH 04/18] nvme-tcp: add definitions for TLS cipher suites Hannes Reinecke
2023-03-22 8:18 ` Sagi Grimberg
2023-03-21 12:43 ` [PATCH 05/18] nvme-tcp: implement recvmsg rx flow for TLS Hannes Reinecke
2023-03-21 13:39 ` Sagi Grimberg
2023-03-21 13:59 ` Hannes Reinecke
2023-03-22 8:01 ` Sagi Grimberg
2023-03-21 12:43 ` [PATCH 06/18] nvme-tcp: call 'queue->data_ready()' in nvme_tcp_data_ready() Hannes Reinecke
2023-03-21 13:44 ` Sagi Grimberg
2023-03-21 14:09 ` Hannes Reinecke
2023-03-22 0:18 ` Chris Leech
2023-03-22 6:59 ` Hannes Reinecke
2023-03-22 8:12 ` Sagi Grimberg [this message]
2023-03-22 8:08 ` Sagi Grimberg
2023-03-22 8:26 ` Hannes Reinecke
2023-03-22 10:13 ` Sagi Grimberg
2023-03-21 12:43 ` [PATCH 07/18] nvme/tcp: allocate socket file Hannes Reinecke
2023-03-21 13:52 ` Sagi Grimberg
2023-03-21 12:43 ` [PATCH 08/18] nvme-tcp: enable TLS handshake upcall Hannes Reinecke
2023-03-22 8:45 ` Sagi Grimberg
2023-03-22 9:12 ` Hannes Reinecke
2023-03-22 10:56 ` Sagi Grimberg
2023-03-22 12:54 ` Hannes Reinecke
2023-03-22 13:16 ` Sagi Grimberg
2023-03-21 12:43 ` [PATCH 09/18] nvme-tcp: add connect option 'tls' Hannes Reinecke
2023-03-22 9:24 ` Sagi Grimberg
2023-03-22 9:59 ` Hannes Reinecke
2023-03-22 10:09 ` Sagi Grimberg
2023-03-21 12:43 ` [PATCH 10/18] nvme-tcp: fixup send workflow for kTLS Hannes Reinecke
2023-03-22 9:31 ` Sagi Grimberg
2023-03-22 10:08 ` Hannes Reinecke
2023-03-22 11:18 ` Sagi Grimberg
2023-03-21 12:43 ` [PATCH 11/18] nvme-tcp: control message handling for recvmsg() Hannes Reinecke
2023-03-22 11:33 ` Sagi Grimberg
2023-03-22 11:48 ` Hannes Reinecke
2023-03-22 11:50 ` Sagi Grimberg
2023-03-22 12:17 ` Hannes Reinecke
2023-03-22 12:29 ` Sagi Grimberg
2023-03-21 12:43 ` [PATCH 12/18] nvmet: make TCP sectype settable via configfs Hannes Reinecke
2023-03-22 11:38 ` Sagi Grimberg
2023-03-21 12:43 ` [PATCH 13/18] nvmet-tcp: allocate socket file Hannes Reinecke
2023-03-22 11:46 ` Sagi Grimberg
2023-03-22 12:07 ` Hannes Reinecke
2023-03-21 12:43 ` [PATCH 14/18] security/keys: export key_lookup() Hannes Reinecke
2023-03-21 12:43 ` [PATCH 15/18] nvmet-tcp: enable TLS handshake upcall Hannes Reinecke
2023-03-22 12:13 ` Sagi Grimberg
2023-03-22 12:34 ` Hannes Reinecke
2023-03-22 12:51 ` Sagi Grimberg
2023-03-22 13:47 ` Hannes Reinecke
2023-03-22 15:42 ` Sagi Grimberg
2023-03-22 16:43 ` Hannes Reinecke
2023-03-22 16:49 ` Chuck Lever III
2023-03-23 7:21 ` Sagi Grimberg
2023-03-24 11:29 ` Hannes Reinecke
2023-03-26 7:18 ` Sagi Grimberg
2023-03-27 6:20 ` Hannes Reinecke
2023-03-28 8:44 ` Sagi Grimberg
2023-03-28 9:20 ` Hannes Reinecke
2023-03-28 9:43 ` Sagi Grimberg
2023-03-28 10:04 ` Hannes Reinecke
2023-03-28 13:22 ` Chuck Lever III
2023-03-28 15:29 ` Sagi Grimberg
2023-03-28 15:56 ` Chuck Lever III
2023-03-29 6:33 ` Sagi Grimberg
2023-03-23 7:44 ` Sagi Grimberg
2023-03-21 12:43 ` [PATCH 16/18] nvmet-tcp: rework sendpage for kTLS Hannes Reinecke
2023-03-22 12:16 ` Sagi Grimberg
2023-03-21 12:43 ` [PATCH 17/18] nvmet-tcp: control messages for recvmsg() Hannes Reinecke
2023-03-21 12:43 ` [PATCH 18/18] nvmet-tcp: peek icreq before starting TLS Hannes Reinecke
2023-03-22 12:24 ` Sagi Grimberg
2023-03-22 12:38 ` Hannes Reinecke
2023-03-21 13:12 ` [RFC PATCH 00/18] nvme: In-kernel TLS support for TCP Sagi Grimberg
2023-03-21 13:30 ` Hannes Reinecke
2023-03-22 8:16 ` Sagi Grimberg
2023-03-22 8:28 ` Hannes Reinecke
2023-03-22 12:53 ` Sagi Grimberg
2023-03-22 15:10 ` Hannes Reinecke
2023-03-22 15:43 ` Sagi Grimberg
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