linux-kernel - RE: [RFC 03/20] vfio: Add vfio_[un]register

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]

Message-ID: <BN9PR11MB5433D4590BA725C79196E0248CA19@BN9PR11MB5433.namprd11.prod.outlook.com>
Date:   Tue, 21 Sep 2021 23:10:15 +0000
From:   "Tian, Kevin" <kevin.tian@...el.com>
To:     Jason Gunthorpe <jgg@...dia.com>, "Liu, Yi L" <yi.l.liu@...el.com>
CC:     "alex.williamson@...hat.com" <alex.williamson@...hat.com>,
        "hch@....de" <hch@....de>,
        "jasowang@...hat.com" <jasowang@...hat.com>,
        "joro@...tes.org" <joro@...tes.org>,
        "jean-philippe@...aro.org" <jean-philippe@...aro.org>,
        "parav@...lanox.com" <parav@...lanox.com>,
        "lkml@...ux.net" <lkml@...ux.net>,
        "pbonzini@...hat.com" <pbonzini@...hat.com>,
        "lushenming@...wei.com" <lushenming@...wei.com>,
        "eric.auger@...hat.com" <eric.auger@...hat.com>,
        "corbet@....net" <corbet@....net>,
        "Raj, Ashok" <ashok.raj@...el.com>,
        "yi.l.liu@...ux.intel.com" <yi.l.liu@...ux.intel.com>,
        "Tian, Jun J" <jun.j.tian@...el.com>, "Wu, Hao" <hao.wu@...el.com>,
        "Jiang, Dave" <dave.jiang@...el.com>,
        "jacob.jun.pan@...ux.intel.com" <jacob.jun.pan@...ux.intel.com>,
        "kwankhede@...dia.com" <kwankhede@...dia.com>,
        "robin.murphy@....com" <robin.murphy@....com>,
        "kvm@...r.kernel.org" <kvm@...r.kernel.org>,
        "iommu@...ts.linux-foundation.org" <iommu@...ts.linux-foundation.org>,
        "dwmw2@...radead.org" <dwmw2@...radead.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "baolu.lu@...ux.intel.com" <baolu.lu@...ux.intel.com>,
        "david@...son.dropbear.id.au" <david@...son.dropbear.id.au>,
        "nicolinc@...dia.com" <nicolinc@...dia.com>
Subject: RE: [RFC 03/20] vfio: Add vfio_[un]register_device()

> From: Jason Gunthorpe <jgg@...dia.com>
> Sent: Wednesday, September 22, 2021 12:01 AM
> 
> On Sun, Sep 19, 2021 at 02:38:31PM +0800, Liu Yi L wrote:
> > With /dev/vfio/devices introduced, now a vfio device driver has three
> > options to expose its device to userspace:
> >
> > a)  only legacy group interface, for devices which haven't been moved to
> >     iommufd (e.g. platform devices, sw mdev, etc.);
> >
> > b)  both legacy group interface and new device-centric interface, for
> >     devices which supports iommufd but also wants to keep backward
> >     compatibility (e.g. pci devices in this RFC);
> >
> > c)  only new device-centric interface, for new devices which don't carry
> >     backward compatibility burden (e.g. hw mdev/subdev with pasid);
> 
> We shouldn't have 'b'? Where does it come from?

a vfio-pci device can be opened via the existing group interface. if no b) it 
means legacy vfio userspace can never use vfio-pci device any more
once the latter is moved to iommufd.

Thanks
Kevin