From: Alex Williamson <alex.williamson@redhat.com>
To: Jason Gunthorpe <jgg@nvidia.com>
Cc: "Tian, Kevin" <kevin.tian@intel.com>,
"Liu, Yi L" <yi.l.liu@intel.com>, "hch@lst.de" <hch@lst.de>,
"jasowang@redhat.com" <jasowang@redhat.com>,
"joro@8bytes.org" <joro@8bytes.org>,
"jean-philippe@linaro.org" <jean-philippe@linaro.org>,
"parav@mellanox.com" <parav@mellanox.com>,
"lkml@metux.net" <lkml@metux.net>,
"pbonzini@redhat.com" <pbonzini@redhat.com>,
"lushenming@huawei.com" <lushenming@huawei.com>,
"eric.auger@redhat.com" <eric.auger@redhat.com>,
"corbet@lwn.net" <corbet@lwn.net>,
"Raj, Ashok" <ashok.raj@intel.com>,
"yi.l.liu@linux.intel.com" <yi.l.liu@linux.intel.com>,
"Tian, Jun J" <jun.j.tian@intel.com>,
"Wu, Hao" <hao.wu@intel.com>,
"Jiang, Dave" <dave.jiang@intel.com>,
"jacob.jun.pan@linux.intel.com" <jacob.jun.pan@linux.intel.com>,
"kwankhede@nvidia.com" <kwankhede@nvidia.com>,
"robin.murphy@arm.com" <robin.murphy@arm.com>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"iommu@lists.linux-foundation.org"
<iommu@lists.linux-foundation.org>,
"dwmw2@infradead.org" <dwmw2@infradead.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"baolu.lu@linux.intel.com" <baolu.lu@linux.intel.com>,
"david@gibson.dropbear.id.au" <david@gibson.dropbear.id.au>,
"nicolinc@nvidia.com" <nicolinc@nvidia.com>
Subject: Re: [RFC 03/20] vfio: Add vfio_[un]register_device()
Date: Wed, 22 Sep 2021 14:10:36 -0600 [thread overview]
Message-ID: <20210922141036.5cd46b2b.alex.williamson@redhat.com> (raw)
In-Reply-To: <20210922122252.GG327412@nvidia.com>
On Wed, 22 Sep 2021 09:22:52 -0300
Jason Gunthorpe <jgg@nvidia.com> wrote:
> On Wed, Sep 22, 2021 at 09:23:34AM +0000, Tian, Kevin wrote:
>
> > > Providing an ioctl to bind to a normal VFIO container or group might
> > > allow a reasonable fallback in userspace..
> >
> > I didn't get this point though. An error in binding already allows the
> > user to fall back to the group path. Why do we need introduce another
> > ioctl to explicitly bind to container via the nongroup interface?
>
> New userspace still needs a fallback path if it hits the 'try and
> fail'. Keeping the device FD open and just using a different ioctl to
> bind to a container/group FD, which new userspace can then obtain as a
> fallback, might be OK.
>
> Hard to see without going through the qemu parts, so maybe just keep
> it in mind
If we assume that the container/group/device interface is essentially
deprecated once we have iommufd, it doesn't make a lot of sense to me
to tack on a container/device interface just so userspace can avoid
reverting to the fully legacy interface.
But why would we create vfio device interface files at all if they
can't work? I'm not really on board with creating a try-and-fail
interface for a mechanism that cannot work for a given device. The
existence of the device interface should indicate that it's supported.
Thanks,
Alex
next prev parent reply other threads:[~2021-09-22 20:10 UTC|newest]
Thread overview: 274+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-19 6:38 [RFC 00/20] Introduce /dev/iommu for userspace I/O address space management Liu Yi L
2021-09-19 6:38 ` [RFC 01/20] iommu/iommufd: Add /dev/iommu core Liu Yi L
2021-09-21 15:41 ` Jason Gunthorpe
2021-09-22 1:51 ` Tian, Kevin
2021-09-22 12:40 ` Jason Gunthorpe
2021-09-22 13:59 ` Tian, Kevin
2021-09-22 14:10 ` Jason Gunthorpe
2021-10-15 9:18 ` Liu, Yi L
2021-10-15 11:18 ` Jason Gunthorpe
2021-10-15 11:29 ` Liu, Yi L
2021-10-19 16:57 ` Jacob Pan
2021-10-19 16:57 ` Jason Gunthorpe
2021-10-19 17:11 ` Jacob Pan
2021-10-19 17:12 ` Jason Gunthorpe
2021-09-19 6:38 ` [RFC 02/20] vfio: Add device class for /dev/vfio/devices Liu Yi L
2021-09-21 15:57 ` Jason Gunthorpe
2021-09-21 23:56 ` Tian, Kevin
2021-09-22 0:55 ` Jason Gunthorpe
2021-09-22 1:07 ` Tian, Kevin
2021-09-22 12:31 ` Jason Gunthorpe
2021-09-22 3:22 ` Tian, Kevin
2021-09-22 12:50 ` Jason Gunthorpe
2021-09-22 14:09 ` Tian, Kevin
2021-09-21 19:56 ` Alex Williamson
2021-09-22 0:56 ` Tian, Kevin
2021-09-29 2:08 ` David Gibson
2021-09-29 19:05 ` Alex Williamson
2021-09-30 2:43 ` David Gibson
2021-10-20 12:39 ` Liu, Yi L
2021-09-19 6:38 ` [RFC 03/20] vfio: Add vfio_[un]register_device() Liu Yi L
2021-09-21 16:01 ` Jason Gunthorpe
2021-09-21 23:10 ` Tian, Kevin
2021-09-22 0:53 ` Jason Gunthorpe
2021-09-22 0:59 ` Tian, Kevin
2021-09-22 9:23 ` Tian, Kevin
2021-09-22 12:22 ` Jason Gunthorpe
2021-09-22 13:44 ` Tian, Kevin
2021-09-22 20:10 ` Alex Williamson [this message]
2021-09-22 22:34 ` Tian, Kevin
2021-09-22 22:45 ` Alex Williamson
2021-09-22 23:45 ` Tian, Kevin
2021-09-22 23:52 ` Jason Gunthorpe
2021-09-23 0:38 ` Tian, Kevin
2021-09-22 23:56 ` Jason Gunthorpe
2021-09-22 0:54 ` Tian, Kevin
2021-09-22 1:00 ` Jason Gunthorpe
2021-09-22 1:02 ` Tian, Kevin
2021-09-23 7:25 ` Eric Auger
2021-09-23 11:44 ` Jason Gunthorpe
2021-09-29 2:46 ` david
2021-09-29 12:22 ` Jason Gunthorpe
2021-09-30 2:48 ` david
2021-09-29 2:43 ` David Gibson
2021-09-29 3:40 ` Tian, Kevin
2021-09-29 5:30 ` Tian, Kevin
2021-09-29 7:08 ` Cornelia Huck
2021-09-29 12:15 ` Jason Gunthorpe
2021-09-19 6:38 ` [RFC 04/20] iommu: Add iommu_device_get_info interface Liu Yi L
2021-09-21 16:19 ` Jason Gunthorpe
2021-09-22 2:31 ` Lu Baolu
2021-09-22 5:07 ` Christoph Hellwig
2021-09-29 2:52 ` David Gibson
2021-09-29 9:25 ` Lu Baolu
2021-09-29 9:29 ` Lu Baolu
2021-09-19 6:38 ` [RFC 05/20] vfio/pci: Register device to /dev/vfio/devices Liu Yi L
2021-09-21 16:40 ` Jason Gunthorpe
2021-09-21 21:09 ` Alex Williamson
2021-09-21 21:58 ` Jason Gunthorpe
2021-09-22 1:24 ` Tian, Kevin
2021-09-22 1:19 ` Tian, Kevin
2021-09-22 21:17 ` Alex Williamson
2021-09-22 23:49 ` Tian, Kevin
2021-09-19 6:38 ` [RFC 06/20] iommu: Add iommu_device_init[exit]_user_dma interfaces Liu Yi L
2021-09-21 17:09 ` Jason Gunthorpe
2021-09-22 1:47 ` Tian, Kevin
2021-09-22 12:39 ` Jason Gunthorpe
2021-09-22 13:56 ` Tian, Kevin
2021-09-27 9:42 ` Tian, Kevin
2021-09-27 11:34 ` Lu Baolu
2021-09-27 13:08 ` Tian, Kevin
2021-09-27 11:53 ` Jason Gunthorpe
2021-09-27 13:00 ` Tian, Kevin
2021-09-27 13:09 ` Jason Gunthorpe
2021-09-27 13:32 ` Tian, Kevin
2021-09-27 14:39 ` Jason Gunthorpe
2021-09-28 7:13 ` Tian, Kevin
2021-09-28 11:54 ` Jason Gunthorpe
2021-09-28 23:59 ` Tian, Kevin
2021-09-27 19:19 ` Alex Williamson
2021-09-28 7:43 ` Tian, Kevin
2021-09-28 16:26 ` Alex Williamson
2021-09-27 15:09 ` Jason Gunthorpe
2021-09-28 7:30 ` Tian, Kevin
2021-09-28 11:57 ` Jason Gunthorpe
2021-09-28 13:35 ` Lu Baolu
2021-09-28 14:07 ` Jason Gunthorpe
2021-09-29 0:38 ` Tian, Kevin
2021-09-29 12:59 ` Jason Gunthorpe
2021-10-15 1:29 ` Tian, Kevin
2021-10-15 11:09 ` Jason Gunthorpe
2021-10-18 1:52 ` Tian, Kevin
2021-09-29 2:22 ` Lu Baolu
2021-09-29 2:29 ` Tian, Kevin
2021-09-29 2:38 ` Lu Baolu
2021-09-29 4:55 ` David Gibson
2021-09-29 5:38 ` Tian, Kevin
2021-09-29 6:35 ` David Gibson
2021-09-29 7:31 ` Tian, Kevin
2021-09-30 3:05 ` David Gibson
2021-09-29 12:57 ` Jason Gunthorpe
2021-09-30 3:09 ` David Gibson
2021-09-30 22:28 ` Jason Gunthorpe
2021-10-01 3:54 ` David Gibson
2021-09-19 6:38 ` [RFC 07/20] iommu/iommufd: Add iommufd_[un]bind_device() Liu Yi L
2021-09-21 17:14 ` Jason Gunthorpe
2021-10-15 9:21 ` Liu, Yi L
2021-09-29 5:25 ` David Gibson
2021-09-29 12:24 ` Jason Gunthorpe
2021-09-30 3:10 ` David Gibson
2021-10-01 12:43 ` Jason Gunthorpe
2021-10-07 1:23 ` David Gibson
2021-10-07 11:35 ` Jason Gunthorpe
2021-10-11 3:24 ` David Gibson
2021-09-19 6:38 ` [RFC 08/20] vfio/pci: Add VFIO_DEVICE_BIND_IOMMUFD Liu Yi L
2021-09-21 17:29 ` Jason Gunthorpe
2021-09-22 21:01 ` Alex Williamson
2021-09-22 23:01 ` Jason Gunthorpe
2021-09-29 6:00 ` David Gibson
2021-09-29 6:41 ` Tian, Kevin
2021-09-29 12:28 ` Jason Gunthorpe
2021-09-29 22:34 ` Tian, Kevin
2021-09-30 3:12 ` David Gibson
2021-09-19 6:38 ` [RFC 09/20] iommu: Add page size and address width attributes Liu Yi L
2021-09-22 13:42 ` Eric Auger
2021-09-22 14:19 ` Tian, Kevin
2021-09-19 6:38 ` [RFC 10/20] iommu/iommufd: Add IOMMU_DEVICE_GET_INFO Liu Yi L
2021-09-21 17:40 ` Jason Gunthorpe
2021-09-22 3:30 ` Tian, Kevin
2021-09-22 12:41 ` Jason Gunthorpe
2021-09-29 6:18 ` david
2021-09-22 21:24 ` Alex Williamson
2021-09-22 23:49 ` Jason Gunthorpe
2021-09-23 3:10 ` Tian, Kevin
2021-09-23 10:15 ` Jean-Philippe Brucker
2021-09-23 11:27 ` Jason Gunthorpe
2021-09-23 12:05 ` Tian, Kevin
2021-09-23 12:22 ` Jason Gunthorpe
2021-09-29 8:48 ` Tian, Kevin
2021-09-29 12:36 ` Jason Gunthorpe
2021-09-30 8:30 ` Tian, Kevin
2021-09-30 10:33 ` Jean-Philippe Brucker
2021-09-30 22:04 ` Jason Gunthorpe
2021-10-01 3:28 ` hch
2021-10-14 8:13 ` Tian, Kevin
2021-10-14 8:22 ` hch
2021-10-14 8:29 ` Tian, Kevin
2021-10-14 8:01 ` Tian, Kevin
2021-10-14 9:16 ` Jean-Philippe Brucker
2021-09-30 8:49 ` Tian, Kevin
2021-09-30 13:43 ` Lu Baolu
2021-10-01 3:24 ` hch
2021-09-30 22:08 ` Jason Gunthorpe
2021-09-23 11:36 ` Jason Gunthorpe
[not found] ` <BN9PR11MB5433409DF766AAEF1BB2CF258CA39@BN9PR11MB5433.namprd11.prod.outlook.com>
2021-09-23 3:38 ` Tian, Kevin
2021-09-23 11:42 ` Jason Gunthorpe
2021-09-30 9:35 ` Tian, Kevin
2021-09-30 22:23 ` Jason Gunthorpe
2021-10-01 3:30 ` hch
2021-10-14 9:11 ` Tian, Kevin
2021-10-14 15:42 ` Jason Gunthorpe
2021-10-15 1:01 ` Tian, Kevin
[not found] ` <BN9PR11MB543327BB6D58AEF91AD2C9D18CB99@BN9PR11MB5433.namprd11.prod.outlook.com>
2021-10-21 2:26 ` Tian, Kevin
2021-10-21 14:58 ` Jean-Philippe Brucker
2021-10-21 23:22 ` Jason Gunthorpe
2021-10-22 7:49 ` Jean-Philippe Brucker
2021-10-25 16:51 ` Jason Gunthorpe
2021-10-21 23:30 ` Jason Gunthorpe
2021-10-22 3:08 ` Tian, Kevin
2021-10-25 23:34 ` Jason Gunthorpe
2021-10-27 1:42 ` Tian, Kevin
2021-10-28 2:07 ` Tian, Kevin
2021-10-29 13:55 ` Jason Gunthorpe
2021-09-29 6:23 ` David Gibson
2021-09-19 6:38 ` [RFC 11/20] iommu/iommufd: Add IOMMU_IOASID_ALLOC/FREE Liu Yi L
2021-09-21 17:44 ` Jason Gunthorpe
2021-09-22 3:40 ` Tian, Kevin
2021-09-22 14:09 ` Jason Gunthorpe
2021-09-23 9:14 ` Tian, Kevin
2021-09-23 12:06 ` Jason Gunthorpe
2021-09-23 12:22 ` Tian, Kevin
2021-09-23 12:31 ` Jason Gunthorpe
2021-09-23 12:45 ` Tian, Kevin
2021-09-23 13:01 ` Jason Gunthorpe
2021-09-23 13:20 ` Tian, Kevin
2021-09-23 13:30 ` Jason Gunthorpe
2021-09-23 13:41 ` Tian, Kevin
2021-10-01 6:30 ` david
2021-10-01 6:26 ` david
2021-10-01 6:19 ` david
2021-10-01 12:25 ` Jason Gunthorpe
2021-10-02 4:21 ` david
2021-10-02 12:25 ` Jason Gunthorpe
2021-10-11 5:37 ` david
2021-10-11 17:17 ` Jason Gunthorpe
2021-10-14 4:33 ` david
2021-10-14 15:06 ` Jason Gunthorpe
2021-10-18 3:40 ` david
2021-10-01 6:15 ` david
2021-09-22 12:51 ` Liu, Yi L
2021-09-22 13:32 ` Jason Gunthorpe
2021-09-23 6:26 ` Liu, Yi L
2021-10-01 6:13 ` David Gibson
2021-10-01 12:22 ` Jason Gunthorpe
2021-10-11 6:02 ` David Gibson
2021-10-11 8:49 ` Jean-Philippe Brucker
2021-10-11 23:38 ` Jason Gunthorpe
2021-10-12 8:33 ` Jean-Philippe Brucker
2021-10-13 7:14 ` Tian, Kevin
2021-10-13 7:07 ` Tian, Kevin
2021-10-14 4:38 ` David Gibson
2021-10-11 18:49 ` Jason Gunthorpe
2021-10-14 4:53 ` David Gibson
2021-10-14 14:52 ` Jason Gunthorpe
2021-10-18 3:50 ` David Gibson
2021-10-18 17:42 ` Jason Gunthorpe
2021-09-22 13:45 ` Jean-Philippe Brucker
2021-09-29 10:47 ` Liu, Yi L
2021-10-01 6:11 ` David Gibson
2021-10-13 7:00 ` Tian, Kevin
2021-10-14 5:00 ` David Gibson
2021-10-14 6:53 ` Tian, Kevin
2021-10-25 5:05 ` David Gibson
2021-10-27 2:32 ` Tian, Kevin
2021-09-19 6:38 ` [RFC 12/20] iommu/iommufd: Add IOMMU_CHECK_EXTENSION Liu Yi L
2021-09-21 17:47 ` Jason Gunthorpe
2021-09-22 3:41 ` Tian, Kevin
2021-09-22 12:55 ` Jason Gunthorpe
2021-09-22 14:13 ` Tian, Kevin
2021-09-19 6:38 ` [RFC 13/20] iommu: Extend iommu_at[de]tach_device() for multiple devices group Liu Yi L
2021-10-14 5:24 ` David Gibson
2021-10-14 7:06 ` Tian, Kevin
2021-10-18 3:57 ` David Gibson
2021-10-18 16:32 ` Jason Gunthorpe
2021-10-25 5:14 ` David Gibson
2021-10-25 12:14 ` Jason Gunthorpe
2021-10-25 13:16 ` David Gibson
2021-10-25 23:36 ` Jason Gunthorpe
2021-10-26 9:23 ` David Gibson
2021-09-19 6:38 ` [RFC 14/20] iommu/iommufd: Add iommufd_device_[de]attach_ioasid() Liu Yi L
2021-09-21 18:02 ` Jason Gunthorpe
2021-09-22 3:53 ` Tian, Kevin
2021-09-22 12:57 ` Jason Gunthorpe
2021-09-22 14:16 ` Tian, Kevin
2021-09-19 6:38 ` [RFC 15/20] vfio/pci: Add VFIO_DEVICE_[DE]ATTACH_IOASID Liu Yi L
2021-09-21 18:04 ` Jason Gunthorpe
2021-09-22 3:56 ` Tian, Kevin
2021-09-22 12:58 ` Jason Gunthorpe
2021-09-22 14:17 ` Tian, Kevin
2021-09-19 6:38 ` [RFC 16/20] vfio/type1: Export symbols for dma [un]map code sharing Liu Yi L
2021-09-21 18:14 ` Jason Gunthorpe
2021-09-22 3:57 ` Tian, Kevin
2021-09-19 6:38 ` [RFC 17/20] iommu/iommufd: Report iova range to userspace Liu Yi L
2021-09-22 14:49 ` Jean-Philippe Brucker
2021-09-29 10:44 ` Liu, Yi L
2021-09-29 12:07 ` Jean-Philippe Brucker
2021-09-29 12:31 ` Jason Gunthorpe
2021-09-19 6:38 ` [RFC 18/20] iommu/iommufd: Add IOMMU_[UN]MAP_DMA on IOASID Liu Yi L
2021-09-19 6:38 ` [RFC 19/20] iommu/vt-d: Implement device_info iommu_ops callback Liu Yi L
2021-09-19 6:38 ` [RFC 20/20] Doc: Add documentation for /dev/iommu Liu Yi L
2021-10-29 0:15 ` David Gibson
2021-10-29 12:44 ` Jason Gunthorpe
2021-09-19 6:45 ` [RFC 00/20] Introduce /dev/iommu for userspace I/O address space management Liu, Yi L
2021-09-21 13:45 ` Jason Gunthorpe
2021-09-22 3:25 ` Liu, Yi L
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