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Date: Wed, 21 May 2025 22:29:59 -0600
From: Keith Busch <kbusch@kernel.org>
To: Caleb Sander Mateos <csander@purestorage.com>
Cc: Keith Busch <kbusch@meta.com>, linux-block@vger.kernel.org,
	linux-nvme@lists.infradead.org
Subject: Re: [PATCH 3/5] nvme: add support for copy offload
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On Wed, May 21, 2025 at 08:41:40PM -0700, Caleb Sander Mateos wrote:
> For the record, that change broke Linux hosts sending DSM commands to
> our NVMe controller, which was validating that the SGL length exactly
> matches the number of data bytes implied by the command. I'm sure
> we're in the minority of NVMe controller vendors in aggressively
> validating the NVMe command parameters, but it was unfortunate to
> discover this change in Linux's behavior.

This is a fabrics target you're talking about? I assume so because pci
would use PRP for a 4k payload, which doesn't encode transfer lengths.
All the offending controllers were pci, so maybe we could have
constrained the DSM over-allocation to that transport if we knew this
was causing problems for fabrics.