linux-kernel - RE: [RFC PATCH 0/7] A General Accelerator Framework, WarpDrive

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Thu, 2 Aug 2018 04:36:52 +0000
From:   "Tian, Kevin" <kevin.tian@...el.com>
To:     Kenneth Lee <liguozhu@...ilicon.com>
CC:     Kenneth Lee <nek.in.cn@...il.com>,
        Herbert Xu <herbert@...dor.apana.org.au>,
        "kvm@...r.kernel.org" <kvm@...r.kernel.org>,
        Jonathan Corbet <corbet@....net>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "linux-doc@...r.kernel.org" <linux-doc@...r.kernel.org>,
        "Kumar, Sanjay K" <sanjay.k.kumar@...el.com>,
        Hao Fang <fanghao11@...wei.com>,
        "iommu@...ts.linux-foundation.org" <iommu@...ts.linux-foundation.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "linuxarm@...wei.com" <linuxarm@...wei.com>,
        Alex Williamson <alex.williamson@...hat.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        "linux-crypto@...r.kernel.org" <linux-crypto@...r.kernel.org>,
        Philippe Ombredanne <pombredanne@...b.com>,
        Zaibo Xu <xuzaibo@...wei.com>,
        "David S . Miller" <davem@...emloft.net>,
        "linux-accelerators@...ts.ozlabs.org" 
        <linux-accelerators@...ts.ozlabs.org>
Subject: RE: [RFC PATCH 0/7] A General Accelerator Framework, WarpDrive

> From: Kenneth Lee
> Sent: Thursday, August 2, 2018 11:40 AM
> 
> On Thu, Aug 02, 2018 at 02:59:33AM +0000, Tian, Kevin wrote:
> > > From: Kenneth Lee
> > > Sent: Wednesday, August 1, 2018 6:22 PM
> > >
> > > From: Kenneth Lee <liguozhu@...ilicon.com>
> > >
> > > WarpDrive is an accelerator framework to expose the hardware
> capabilities
> > > directly to the user space. It makes use of the exist vfio and vfio-mdev
> > > facilities. So the user application can send request and DMA to the
> > > hardware without interaction with the kernel. This remove the latency
> > > of syscall and context switch.
> > >
> > > The patchset contains documents for the detail. Please refer to it for
> more
> > > information.
> > >
> > > This patchset is intended to be used with Jean Philippe Brucker's SVA
> > > patch [1] (Which is also in RFC stage). But it is not mandatory. This
> > > patchset is tested in the latest mainline kernel without the SVA patches.
> > > So it support only one process for each accelerator.
> >
> > If no sharing, then why not just assigning the whole parent device to
> > the process? IMO if SVA usage is the clear goal of your series, it
> > might be made clearly so then Jean's series is mandatory dependency...
> >
> 
> We don't know how SVA will be finally. But the feature, "make use of
> per-PASID/substream ID IOMMU page table", should be able to be enabled
> in the
> kernel. So we don't want to enforce it here. After we have this serial ready,
> it
> can be hooked to any implementation.

"any" or "only queue-based" implementation? some devices may not
have queue concept, e.g. GPU.

> 
> Further more, even without "per-PASID IOMMU page table", this series has
> its
> value. It is not simply dedicate the whole device to the process. It "shares"
> the device with the kernel driver. So you can support crypto and a user
> application at the same time.

OK.

Thanks
Kevin