From: Christoph Hellwig <hch@lst.de>
To: Keith Busch <kbusch@kernel.org>
Cc: Marta Rybczynska <mrybczyn@kalray.eu>,
Christoph Hellwig <hch@lst.de>, axboe <axboe@fb.com>,
Sagi Grimberg <sagi@grimberg.me>,
linux-nvme <linux-nvme@lists.infradead.org>,
linux-kernel <linux-kernel@vger.kernel.org>,
Samuel Jones <sjones@kalray.eu>,
Guillaume Missonnier <gmissonnier@kalray.eu>
Subject: Re: [PATCH v2] nvme: allow 64-bit results in passthru commands
Date: Thu, 22 Aug 2019 01:59:16 +0200 [thread overview]
Message-ID: <20190821235916.GE9511@lst.de> (raw)
In-Reply-To: <20190819144922.GC6883@localhost.localdomain>
On Mon, Aug 19, 2019 at 08:49:22AM -0600, Keith Busch wrote:
> On Mon, Aug 19, 2019 at 12:06:23AM -0700, Marta Rybczynska wrote:
> > ----- On 16 Aug, 2019, at 15:16, Christoph Hellwig hch@lst.de wrote:
> > > Sorry for not replying to the earlier version, and thanks for doing
> > > this work.
> > >
> > > I wonder if instead of using our own structure we'd just use
> > > a full nvme SQE for the input and CQE for that output. Even if we
> > > reserve a few fields that means we are ready for any newly used
> > > field (at least until the SQE/CQE sizes are expanded..).
> >
> > We could do that, nvme_command and nvme_completion are already UAPI.
> > On the other hand that would mean not filling out certain fields like
> > command_id. Can do an approach like this.
>
> Well, we need to pass user space addresses and lengths, which isn't
> captured in struct nvme_command.
Well, the address would fit into the data pointer. But yes, the lack
of a command length concept in nvme makes this idea a mess and not
really workable.
next prev parent reply other threads:[~2019-08-21 23:59 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-16 9:47 [PATCH v2] nvme: allow 64-bit results in passthru commands Marta Rybczynska
2019-08-16 13:16 ` Christoph Hellwig
2019-08-19 7:06 ` Marta Rybczynska
2019-08-19 14:49 ` Keith Busch
2019-08-19 15:57 ` James Smart
2019-08-19 18:56 ` Sagi Grimberg
2019-08-19 18:57 ` Keith Busch
2019-08-19 21:17 ` Sagi Grimberg
2019-08-19 21:21 ` Keith Busch
2019-08-21 23:59 ` Christoph Hellwig [this message]
2019-08-22 0:06 ` Christoph Hellwig
2019-08-26 11:20 ` Marta Rybczynska
2019-09-02 8:29 ` Christoph Hellwig
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