From: "Tian, Kevin" <kevin.tian@intel.com>
To: Jason Gunthorpe <jgg@nvidia.com>, "Liu, Yi L" <yi.l.liu@intel.com>
Cc: "alex.williamson@redhat.com" <alex.williamson@redhat.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 12/20] iommu/iommufd: Add IOMMU_CHECK_EXTENSION
Date: Wed, 22 Sep 2021 03:41:50 +0000 [thread overview]
Message-ID: <BN9PR11MB54334A552C3E606F4394EF298CA29@BN9PR11MB5433.namprd11.prod.outlook.com> (raw)
In-Reply-To: <20210921174711.GX327412@nvidia.com>
> From: Jason Gunthorpe <jgg@nvidia.com>
> Sent: Wednesday, September 22, 2021 1:47 AM
>
> On Sun, Sep 19, 2021 at 02:38:40PM +0800, Liu Yi L wrote:
> > As aforementioned, userspace should check extension for what formats
> > can be specified when allocating an IOASID. This patch adds such
> > interface for userspace. In this RFC, iommufd reports EXT_MAP_TYPE1V2
> > support and no no-snoop support yet.
> >
> > Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
> > drivers/iommu/iommufd/iommufd.c | 7 +++++++
> > include/uapi/linux/iommu.h | 27 +++++++++++++++++++++++++++
> > 2 files changed, 34 insertions(+)
> >
> > diff --git a/drivers/iommu/iommufd/iommufd.c
> b/drivers/iommu/iommufd/iommufd.c
> > index 4839f128b24a..e45d76359e34 100644
> > +++ b/drivers/iommu/iommufd/iommufd.c
> > @@ -306,6 +306,13 @@ static long iommufd_fops_unl_ioctl(struct file
> *filep,
> > return ret;
> >
> > switch (cmd) {
> > + case IOMMU_CHECK_EXTENSION:
> > + switch (arg) {
> > + case EXT_MAP_TYPE1V2:
> > + return 1;
> > + default:
> > + return 0;
> > + }
> > case IOMMU_DEVICE_GET_INFO:
> > ret = iommufd_get_device_info(ictx, arg);
> > break;
> > diff --git a/include/uapi/linux/iommu.h b/include/uapi/linux/iommu.h
> > index 5cbd300eb0ee..49731be71213 100644
> > +++ b/include/uapi/linux/iommu.h
> > @@ -14,6 +14,33 @@
> > #define IOMMU_TYPE (';')
> > #define IOMMU_BASE 100
> >
> > +/*
> > + * IOMMU_CHECK_EXTENSION - _IO(IOMMU_TYPE, IOMMU_BASE + 0)
> > + *
> > + * Check whether an uAPI extension is supported.
> > + *
> > + * It's unlikely that all planned capabilities in IOMMU fd will be ready
> > + * in one breath. User should check which uAPI extension is supported
> > + * according to its intended usage.
> > + *
> > + * A rough list of possible extensions may include:
> > + *
> > + * - EXT_MAP_TYPE1V2 for vfio type1v2 map semantics;
> > + * - EXT_DMA_NO_SNOOP for no-snoop DMA support;
> > + * - EXT_MAP_NEWTYPE for an enhanced map semantics;
> > + * - EXT_MULTIDEV_GROUP for 1:N iommu group;
> > + * - EXT_IOASID_NESTING for what the name stands;
> > + * - EXT_USER_PAGE_TABLE for user managed page table;
> > + * - EXT_USER_PASID_TABLE for user managed PASID table;
> > + * - EXT_DIRTY_TRACKING for tracking pages dirtied by DMA;
> > + * - ...
> > + *
> > + * Return: 0 if not supported, 1 if supported.
> > + */
> > +#define EXT_MAP_TYPE1V2 1
> > +#define EXT_DMA_NO_SNOOP 2
> > +#define IOMMU_CHECK_EXTENSION _IO(IOMMU_TYPE,
> IOMMU_BASE + 0)
>
> I generally advocate for a 'try and fail' approach to discovering
> compatibility.
>
> If that doesn't work for the userspace then a query to return a
> generic capability flag is the next best idea. Each flag should
> clearly define what 'try and fail' it is talking about
We don't have strong preference here. Just follow what vfio does
today. So Alex's opinion is appreciated here. 😊
>
> Eg dma_no_snoop is about creating an IOS with flag NO SNOOP set
>
> TYPE1V2 seems like nonsense
just in case other mapping protocols are introduced in the future
>
> Not sure about the others.
>
> IOW, this should recast to a generic 'query capabilities' IOCTL
>
> Jason
next prev parent reply other threads:[~2021-09-22 3:41 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
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 [this message]
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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