From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jason Gunthorpe <jgg-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
Subject: Re: [PATCH V4 05/18] iommu/ioasid: Redefine IOASID set and
 allocation APIs
Date: Fri, 19 Mar 2021 09:46:45 -0300
Message-ID: <20210319124645.GP2356281@nvidia.com>
References: <1614463286-97618-1-git-send-email-jacob.jun.pan@linux.intel.com>
 <1614463286-97618-6-git-send-email-jacob.jun.pan@linux.intel.com>
 <20210318172234.3e8c34f7@jacob-builder> <YFR10eeDVf5ZHV5l@myrica>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Return-path: <iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org>
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com;
 s=selector2;
 h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck;
 bh=u/nsU6ATM1M8lSjy/TMu9GVYVVA4i5cKPjws1WsiPcE=;
 b=uEritXANFQG9Bn/p5GsiLsdhMB3nJCOyTybyQHux5rmSPPBo2G6ryAUzXwr++B8XxBaveDtPL64dDaB5Q3iVDRzLcT5fPyntxu1W2y0RXngGQ8hPvLx/w9j0+MzTnnaLJCYawYG/x3kjvC9gLCw5yEKGZBs2CpquGEt3I1ooO+2UEwi1Emf+O9TJpdsubfCqnK/bwcl1yRHFdi12VZv7UxAE42iQihPC/gVX7iduaCJeB6RV5UZR/RpiYwz90nmYkHCR6zTDUNHtW/xtyT1qVIApYU/Rr5geV4OZk71gQp5nkk1YE4C01mjmHvm+lMqutkbIrv9AkoHagzMm9/iB7g==
Content-Disposition: inline
In-Reply-To: <YFR10eeDVf5ZHV5l@myrica>
List-Id: <cgroups.vger.kernel.org>
List-Unsubscribe: <https://lists.linuxfoundation.org/mailman/options/iommu>,
 <mailto:iommu-request-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org?subject=unsubscribe>
List-Archive: <http://lists.linuxfoundation.org/pipermail/iommu/>
List-Post: <mailto:iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org>
List-Help: <mailto:iommu-request-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org?subject=help>
List-Subscribe: <https://lists.linuxfoundation.org/mailman/listinfo/iommu>,
 <mailto:iommu-request-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org?subject=subscribe>
Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org
Sender: "iommu" <iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org>
To: Jean-Philippe Brucker <jean-philippe-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Cc: "Tian, Kevin" <kevin.tian-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>, Alex Williamson <alex.williamson-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>, Raj Ashok <ashok.raj-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>, Jonathan Corbet <corbet-T1hC0tSOHrs@public.gmane.org>, Jean-Philippe Brucker <jean-philippe-68IGFXMjmZ7QT0dZR+AlfA@public.gmane.org>, LKML <linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>, Dave Jiang <dave.jiang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, Li Zefan <lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>, Johannes Weiner <hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org>, Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Wu Hao <hao.wu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>, David Woodhouse <dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>

On Fri, Mar 19, 2021 at 10:58:41AM +0100, Jean-Philippe Brucker wrote:

> Although there is no use for it at the moment (only two upstream users and
> it looks like amdkfd always uses current too), I quite like the
> client-server model where the privileged process does bind() and programs
> the hardware queue on behalf of the client process.

This creates a lot complexity, how do does process A get a secure
reference to B? How does it access the memory in B to setup the HW?

Why do we need separation anyhow? SVM devices are supposed to be
secure or they shouldn't do SVM.

Jason