From: Fenghua Yu <fenghua.yu@intel.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
H Peter Anvin <hpa@zytor.com>,
David Woodhouse <dwmw2@infradead.org>,
Lu Baolu <baolu.lu@linux.intel.com>,
Dave Hansen <dave.hansen@intel.com>,
Tony Luck <tony.luck@intel.com>, Ashok Raj <ashok.raj@intel.com>,
Jacob Jun Pan <jacob.jun.pan@intel.com>,
Dave Jiang <dave.jiang@intel.com>,
Sohil Mehta <sohil.mehta@intel.com>,
Ravi V Shankar <ravi.v.shankar@intel.com>,
linux-kernel <linux-kernel@vger.kernel.org>, x86 <x86@kernel.org>,
iommu@lists.linux-foundation.org
Subject: Re: [PATCH 1/7] docs: x86: Add a documentation for ENQCMD
Date: Mon, 27 Apr 2020 13:13:57 -0700 [thread overview]
Message-ID: <20200427201357.GB242333@romley-ivt3.sc.intel.com> (raw)
In-Reply-To: <87368qtsqz.fsf@nanos.tec.linutronix.de>
On Sun, Apr 26, 2020 at 01:02:12PM +0200, Thomas Gleixner wrote:
> Fenghua Yu <fenghua.yu@intel.com> writes:
>
> s/Add a documentation/Add documentation/
>
> > From: Ashok Raj <ashok.raj@intel.com>
> >
> > ENQCMD and Data Streaming Accelerator (DSA) and all of their associated
> > features are a complicated stack with lots of interconnected pieces.
> > This documentation provides a big picture overview for all of the
> > features.
> >
> > Signed-off-by: Ashok Raj <ashok.raj@intel.com>
> > Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
> > Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
> > Reviewed-by: Tony Luck <tony.luck@intel.com>
> > ---
> > Documentation/x86/enqcmd.rst | 185 +++++++++++++++++++++++++++++++++++
>
> How is that hooked up into the Documentation index?
>
> Documentation/x86/enqcmd.rst: WARNING: document isn't included in any toctree
>
> > +++ b/Documentation/x86/enqcmd.rst
> > @@ -0,0 +1,185 @@
> > +.. SPDX-License-Identifier: GPL-2.0
> > +
> > +Improved Device Interaction Overview
>
> So the document is about ENQCMD, right? Can you please make that in some
> way consistently named?
>
> > +
> > +== Background ==
>
> This lacks any docbook formatting.... The resulting HTML looks like ...
>
> > +
> > +Shared Virtual Addressing (SVA) allows the processor and device to use the
> > +same virtual addresses avoiding the need for software to translate virtual
> > +addresses to physical addresses. ENQCMD is a new instruction on Intel
> > +platforms that allows user applications to directly notify hardware of new
> > +work, much like doorbells are used in some hardware, but carries a payload
> > +that carries the PASID and some additional device specific commands
> > +along with it.
>
> Sorry that's not background information, that's an agglomeration of
> words.
>
> Can you please explain properly what's the background of SVA, how it
> differs from regular device addressing and what kind of requirements it
> has?
>
> ENQCMD is not related to background. It's part of the new technology.
>
> > +== Address Space Tagging ==
> > +
> > +A new MSR (MSR_IA32_PASID) allows an application address space to be
> > +associated with what the PCIe spec calls a Process Address Space ID
> > +(PASID). This PASID tag is carried along with all requests between
> > +applications and devices and allows devices to interact with the process
> > +address space.
>
> Sigh. The important part here is not the MSR. The important part is to
> explain what PASID is and where it comes from. Documentation has similar
> rules as changelogs:
>
> 1) Provide context
>
> 2) Explain requirements
>
> 3) Explain implementation
>
> The pile you provided is completely backwards and unstructured.
Ok. Will address all of the comments.
Thanks.
-Fenghua
next prev parent reply other threads:[~2020-04-27 20:14 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-30 19:33 [PATCH 0/7] x86: tag application address space for devices Fenghua Yu
2020-03-30 19:33 ` [PATCH 1/7] docs: x86: Add a documentation for ENQCMD Fenghua Yu
2020-04-26 11:02 ` Thomas Gleixner
2020-04-27 20:13 ` Fenghua Yu [this message]
2020-03-30 19:33 ` [PATCH 2/7] x86/cpufeatures: Enumerate ENQCMD and ENQCMDS instructions Fenghua Yu
2020-04-26 11:06 ` Thomas Gleixner
2020-04-27 20:17 ` Fenghua Yu
2020-03-30 19:33 ` [PATCH 3/7] x86/fpu/xstate: Add supervisor PASID state for ENQCMD feature Fenghua Yu
2020-04-26 11:17 ` Thomas Gleixner
2020-04-27 20:33 ` Fenghua Yu
2020-03-30 19:33 ` [PATCH 4/7] x86/msr-index: Define IA32_PASID MSR Fenghua Yu
2020-04-26 11:22 ` Thomas Gleixner
2020-04-27 20:50 ` Fenghua Yu
2020-03-30 19:33 ` [PATCH 5/7] x86/mmu: Allocate/free PASID Fenghua Yu
2020-04-26 14:55 ` Thomas Gleixner
2020-04-27 22:18 ` Fenghua Yu
2020-04-27 23:44 ` Thomas Gleixner
2020-04-28 18:21 ` Jacob Pan (Jun)
2020-04-28 18:54 ` Thomas Gleixner
2020-04-28 19:07 ` Luck, Tony
2020-04-28 20:42 ` Jacob Pan (Jun)
2020-04-28 20:59 ` Luck, Tony
2020-04-28 22:13 ` Jacob Pan (Jun)
2020-04-28 22:32 ` Luck, Tony
2020-04-28 20:40 ` Jacob Pan (Jun)
2020-04-28 20:57 ` Fenghua Yu
2020-03-30 19:33 ` [PATCH 6/7] x86/traps: Fix up invalid PASID Fenghua Yu
2020-04-26 15:25 ` Thomas Gleixner
2020-04-27 20:11 ` Fenghua Yu
2020-04-28 0:13 ` Thomas Gleixner
2020-04-27 22:46 ` Raj, Ashok
2020-04-27 23:08 ` Luck, Tony
2020-04-28 0:20 ` Thomas Gleixner
2020-04-28 0:54 ` Thomas Gleixner
2020-04-28 1:08 ` Raj, Ashok
2020-03-30 19:33 ` [PATCH 7/7] x86/process: Clear PASID state for a newly forked/cloned thread Fenghua Yu
2020-04-22 20:41 ` [PATCH 0/7] x86: tag application address space for devices Fenghua Yu
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=20200427201357.GB242333@romley-ivt3.sc.intel.com \
--to=fenghua.yu@intel.com \
--cc=ashok.raj@intel.com \
--cc=baolu.lu@linux.intel.com \
--cc=bp@alien8.de \
--cc=dave.hansen@intel.com \
--cc=dave.jiang@intel.com \
--cc=dwmw2@infradead.org \
--cc=hpa@zytor.com \
--cc=iommu@lists.linux-foundation.org \
--cc=jacob.jun.pan@intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=ravi.v.shankar@intel.com \
--cc=sohil.mehta@intel.com \
--cc=tglx@linutronix.de \
--cc=tony.luck@intel.com \
--cc=x86@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;
as well as URLs for NNTP newsgroup(s).