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Date:   Tue, 8 Jun 2021 11:15:01 +1000
From:   David Gibson <david@gibson.dropbear.id.au>
To:     Jason Gunthorpe <jgg@nvidia.com>
Cc:     "Enrico Weigelt, metux IT consult" <lkml@metux.net>,
        "Tian, Kevin" <kevin.tian@intel.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Joerg Roedel <joro@8bytes.org>,
        Lu Baolu <baolu.lu@linux.intel.com>,
        David Woodhouse <dwmw2@infradead.org>,
        "iommu@lists.linux-foundation.org" <iommu@lists.linux-foundation.org>,
        "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
        "Alex Williamson (alex.williamson@redhat.com)" 
        <alex.williamson@redhat.com>, Jason Wang <jasowang@redhat.com>,
        Eric Auger <eric.auger@redhat.com>,
        Jonathan Corbet <corbet@lwn.net>,
        "Raj, Ashok" <ashok.raj@intel.com>,
        "Liu, Yi L" <yi.l.liu@intel.com>, "Wu, Hao" <hao.wu@intel.com>,
        "Jiang, Dave" <dave.jiang@intel.com>,
        Jacob Pan <jacob.jun.pan@linux.intel.com>,
        Jean-Philippe Brucker <jean-philippe@linaro.org>,
        Kirti Wankhede <kwankhede@nvidia.com>,
        Robin Murphy <robin.murphy@arm.com>
Subject: Re: [RFC] /dev/ioasid uAPI proposal
Message-ID: <YL7Elf3KwRarNfLx@yekko>
References: <MWHPR11MB1886422D4839B372C6AB245F8C239@MWHPR11MB1886.namprd11.prod.outlook.com>
 <bb6846bf-bd3c-3802-e0d7-226ec9b33384@metux.net>
 <20210602172424.GD1002214@nvidia.com>
 <bd0f485c-5f70-b087-2a5a-d2fe6e16817d@metux.net>
 <20210604123054.GL1002214@nvidia.com>
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On Fri, Jun 04, 2021 at 09:30:54AM -0300, Jason Gunthorpe wrote:
> On Fri, Jun 04, 2021 at 12:44:28PM +0200, Enrico Weigelt, metux IT consul=
t wrote:
> > On 02.06.21 19:24, Jason Gunthorpe wrote:
> >=20
> > Hi,
> >=20
> > >> If I understand this correctly, /dev/ioasid is a kind of "common
> > supplier"
> > >> to other APIs / devices. Why can't the fd be acquired by the
> > >> consumer APIs (eg. kvm, vfio, etc) ?
> > >
> > > /dev/ioasid would be similar to /dev/vfio, and everything already
> > > deals with exposing /dev/vfio and /dev/vfio/N together
> > >
> > > I don't see it as a problem, just more work.
> >=20
> > One of the problems I'm seeing is in container environments: when
> > passing in an vfio device, we now also need to pass in /dev/ioasid,
> > thus increasing the complexity in container setup (or orchestration).
>=20
> Containers already needed to do this today. Container orchestration is
> hard.

Right to use VFIO a container already needs both /dev/vfio and one or
more /dev/vfio/NNN group devices.

--=20
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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