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Date: Fri, 26 Apr 2024 09:16:44 -0700
From: Dan Williams <dan.j.williams@intel.com>
To: Jonathan Cameron <Jonathan.Cameron@huawei.com>, Dan Williams
	<dan.j.williams@intel.com>
CC: <linux-cxl@vger.kernel.org>, Sreenivas Bagalkote
	<sreenivas.bagalkote@broadcom.com>, Brett Henning
	<brett.henning@broadcom.com>, Harold Johnson <harold.johnson@broadcom.com>,
	Sumanesh Samanta <sumanesh.samanta@broadcom.com>,
	<linux-kernel@vger.kernel.org>, Davidlohr Bueso <dave@stgolabs.net>, "Dave
 Jiang" <dave.jiang@intel.com>, Alison Schofield <alison.schofield@intel.com>,
	Vishal Verma <vishal.l.verma@intel.com>, Ira Weiny <ira.weiny@intel.com>,
	<linuxarm@huawei.com>, <linux-api@vger.kernel.org>, Lorenzo Pieralisi
	<lpieralisi@kernel.org>, "Natu, Mahesh" <mahesh.natu@intel.com>,
	<gregkh@linuxfoundation.org>
Subject: Re: RFC: Restricting userspace interfaces for CXL fabric management
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Jonathan Cameron wrote:
[..]
> To give people an incentive to play the standards game we have to
> provide an alternative.  Userspace libraries will provide some incentive
> to standardize if we have enough vendors (we don't today - so they will
> do their own libraries), but it is a lot easier to encourage if we
> exercise control over the interface.

Yes, and I expect you and I are not far off on what can be done
here.

However, lets cut to a sentiment hanging over this discussion. Referring
to vendor specific commands:

    "CXL spec has them for a reason and they need to be supported."

..that is an aggressive "vendor specific first" sentiment that
generates an aggressive "userspace drivers" reaction, because the best
way to get around community discussions about what ABI makes sense is
userspace drivers.

Now, if we can step back to where this discussion started, where typical
Linux collaboration shines, and where I think you and I are more aligned
than this thread would indicate, is "vendor specific last". Lets
carefully consider the vendor specific commands that are candidates to
be de facto cross vendor semantics if not de jure standards.