From: "Martin K. Petersen" <martin.petersen@oracle.com>
To: Kanchan Joshi <joshi.k@samsung.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>,
Anuj Gupta <anuj20.g@samsung.com>,
axboe@kernel.dk, hch@lst.de, kbusch@kernel.org,
asml.silence@gmail.com, krisman@suse.de,
io-uring@vger.kernel.org, linux-nvme@lists.infradead.org,
linux-block@vger.kernel.org, gost.dev@samsung.com,
linux-scsi@vger.kernel.org
Subject: Re: [PATCH v3 09/10] nvme: add handling for app_tag
Date: Thu, 12 Sep 2024 22:05:03 -0400 [thread overview]
Message-ID: <yq1a5gctipx.fsf@ca-mkp.ca.oracle.com> (raw)
In-Reply-To: <efe8215a-9b02-9dfe-db84-988e15d4abcf@samsung.com> (Kanchan Joshi's message of "Thu, 29 Aug 2024 15:48:44 +0530")
Kanchan,
>> This assumes the app tag is the same for every block in the I/O?
>> That's not how it's typically used (to the extent that it is used at
>> all due to the value 0xffff acting as escape).
>>
>
> NVMe spec allows only one value to be passed in each read/write
> command (LBAT for write, and ELBAT for read). And that's what
> controller checks for the entire block range covered by one command.
> So per-io tag rather than per-block tag. The integrity buffer creator
> is supposed to put the same application-tag for each block if it is
> sending multi-block IO.
I am OK with that approach as long as the mask is only applied when
checking is enabled.
I.e. I don't have a use case for checking less than the full app tag.
But almost all users of PI I am aware of depend on being able to put
different values in the app tag for different blocks in the I/O when
checking is disabled.
--
Martin K. Petersen Oracle Linux Engineering
next prev parent reply other threads:[~2024-09-13 2:05 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20240823104552epcas5p226dbbbd448cd0ee0955ffdd3ad1b112d@epcas5p2.samsung.com>
2024-08-23 10:38 ` [PATCH v3 00/10] Read/Write with meta/integrity Anuj Gupta
2024-08-23 10:38 ` [PATCH v3 01/10] block: define set of integrity flags to be inherited by cloned bip Anuj Gupta
2024-08-24 8:24 ` Christoph Hellwig
2024-08-29 3:05 ` Martin K. Petersen
2024-08-23 10:38 ` [PATCH v3 02/10] block: introduce a helper to determine metadata bytes from data iter Anuj Gupta
2024-08-24 8:24 ` Christoph Hellwig
2024-08-29 3:06 ` Martin K. Petersen
2024-08-23 10:38 ` [PATCH v3 03/10] block: handle split correctly for user meta bounce buffer Anuj Gupta
2024-08-24 8:31 ` Christoph Hellwig
2024-08-28 11:18 ` Anuj Gupta
2024-08-29 4:04 ` Christoph Hellwig
2024-08-23 10:38 ` [PATCH v3 04/10] block: modify bio_integrity_map_user to accept iov_iter as argument Anuj Gupta
2024-08-23 10:38 ` [PATCH v3 05/10] block: define meta io descriptor Anuj Gupta
2024-08-24 8:31 ` Christoph Hellwig
2024-08-29 3:05 ` Martin K. Petersen
2024-08-23 10:38 ` [PATCH v3 06/10] io_uring/rw: add support to send meta along with read/write Anuj Gupta
2024-08-24 8:33 ` Christoph Hellwig
2024-08-23 10:38 ` [PATCH v3 07/10] block: introduce BIP_CHECK_GUARD/REFTAG/APPTAG bip_flags Anuj Gupta
2024-08-24 8:35 ` Christoph Hellwig
2024-08-28 13:42 ` Kanchan Joshi
2024-08-29 3:16 ` Martin K. Petersen
2024-08-29 4:06 ` Christoph Hellwig
2024-08-29 13:29 ` Anuj gupta
2024-09-12 12:40 ` Anuj Gupta
2024-09-13 2:06 ` Martin K. Petersen
2024-08-29 4:06 ` Christoph Hellwig
2024-08-23 10:38 ` [PATCH v3 07/10] block,nvme: " Anuj Gupta
2024-08-23 10:38 ` [PATCH v3 08/10] block: add support to pass user meta buffer Anuj Gupta
2024-08-24 8:44 ` Christoph Hellwig
2024-08-23 10:38 ` [PATCH v3 09/10] nvme: add handling for app_tag Anuj Gupta
2024-08-24 8:49 ` Christoph Hellwig
2024-08-29 3:00 ` Martin K. Petersen
2024-08-29 10:18 ` Kanchan Joshi
2024-09-13 2:05 ` Martin K. Petersen [this message]
2024-08-23 10:38 ` [PATCH v3 10/10] scsi: add support for user-meta interface Anuj Gupta
2024-08-24 8:52 ` Christoph Hellwig
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=yq1a5gctipx.fsf@ca-mkp.ca.oracle.com \
--to=martin.petersen@oracle.com \
--cc=anuj20.g@samsung.com \
--cc=asml.silence@gmail.com \
--cc=axboe@kernel.dk \
--cc=gost.dev@samsung.com \
--cc=hch@lst.de \
--cc=io-uring@vger.kernel.org \
--cc=joshi.k@samsung.com \
--cc=kbusch@kernel.org \
--cc=krisman@suse.de \
--cc=linux-block@vger.kernel.org \
--cc=linux-nvme@lists.infradead.org \
--cc=linux-scsi@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox