From: Alex Williamson <alex.williamson@redhat.com>
To: David Gibson <david@gibson.dropbear.id.au>
Cc: kvm@vger.kernel.org, jasowang@redhat.com, kwankhede@nvidia.com,
hch@lst.de, jean-philippe@linaro.org, dave.jiang@intel.com,
ashok.raj@intel.com, corbet@lwn.net, jgg@nvidia.com,
kevin.tian@intel.com, parav@mellanox.com, lkml@metux.net,
dwmw2@infradead.org, jun.j.tian@intel.com,
linux-kernel@vger.kernel.org, lushenming@huawei.com,
iommu@lists.linux-foundation.org, pbonzini@redhat.com,
robin.murphy@arm.com
Subject: Re: [RFC 02/20] vfio: Add device class for /dev/vfio/devices
Date: Wed, 29 Sep 2021 13:05:21 -0600 [thread overview]
Message-ID: <20210929130521.738c56ed.alex.williamson@redhat.com> (raw)
In-Reply-To: <YVPKu/F3IpPMtGCh@yekko>
On Wed, 29 Sep 2021 12:08:59 +1000
David Gibson <david@gibson.dropbear.id.au> wrote:
> On Sun, Sep 19, 2021 at 02:38:30PM +0800, Liu Yi L wrote:
> > This patch introduces a new interface (/dev/vfio/devices/$DEVICE) for
> > userspace to directly open a vfio device w/o relying on container/group
> > (/dev/vfio/$GROUP). Anything related to group is now hidden behind
> > iommufd (more specifically in iommu core by this RFC) in a device-centric
> > manner.
> >
> > In case a device is exposed in both legacy and new interfaces (see next
> > patch for how to decide it), this patch also ensures that when the device
> > is already opened via one interface then the other one must be blocked.
> >
> > Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
> [snip]
>
> > +static bool vfio_device_in_container(struct vfio_device *device)
> > +{
> > + return !!(device->group && device->group->container);
>
> You don't need !! here. && is already a logical operation, so returns
> a valid bool.
>
> > +}
> > +
> > static int vfio_device_fops_release(struct inode *inode, struct file *filep)
> > {
> > struct vfio_device *device = filep->private_data;
> > @@ -1560,7 +1691,16 @@ static int vfio_device_fops_release(struct inode *inode, struct file *filep)
> >
> > module_put(device->dev->driver->owner);
> >
> > - vfio_group_try_dissolve_container(device->group);
> > + if (vfio_device_in_container(device)) {
> > + vfio_group_try_dissolve_container(device->group);
> > + } else {
> > + atomic_dec(&device->opened);
> > + if (device->group) {
> > + mutex_lock(&device->group->opened_lock);
> > + device->group->opened--;
> > + mutex_unlock(&device->group->opened_lock);
> > + }
> > + }
> >
> > vfio_device_put(device);
> >
> > @@ -1613,6 +1753,7 @@ static int vfio_device_fops_mmap(struct file *filep, struct vm_area_struct *vma)
> >
> > static const struct file_operations vfio_device_fops = {
> > .owner = THIS_MODULE,
> > + .open = vfio_device_fops_open,
> > .release = vfio_device_fops_release,
> > .read = vfio_device_fops_read,
> > .write = vfio_device_fops_write,
> > @@ -2295,6 +2436,52 @@ static struct miscdevice vfio_dev = {
> > .mode = S_IRUGO | S_IWUGO,
> > };
> >
> > +static char *vfio_device_devnode(struct device *dev, umode_t *mode)
> > +{
> > + return kasprintf(GFP_KERNEL, "vfio/devices/%s", dev_name(dev));
>
> Others have pointed out some problems with the use of dev_name()
> here. I'll add that I think you'll make things much easier if instead
> of using one huge "devices" subdir, you use a separate subdir for each
> vfio sub-driver (so, one for PCI, one for each type of mdev, one for
> platform, etc.). That should make avoiding name conflicts a lot simpler.
It seems like this is unnecessary if we use the vfioX naming approach.
Conflicts are trivial to ignore if we don't involve dev_name() and
looking for the correct major:minor chardev in the correct subdirectory
seems like a hassle for userspace. Thanks,
Alex
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
next prev parent reply other threads:[~2021-09-29 19:05 UTC|newest]
Thread overview: 263+ 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 via iommu
2021-09-22 1:51 ` Tian, Kevin
2021-09-22 12:40 ` Jason Gunthorpe via iommu
2021-09-22 13:59 ` Tian, Kevin
2021-09-22 14:10 ` Jason Gunthorpe via iommu
2021-10-15 9:18 ` Liu, Yi L
2021-10-15 11:18 ` Jason Gunthorpe via iommu
2021-10-15 11:29 ` Liu, Yi L
2021-10-19 16:57 ` Jacob Pan
2021-10-19 16:57 ` Jason Gunthorpe via iommu
2021-10-19 17:11 ` Jacob Pan
2021-10-19 17:12 ` Jason Gunthorpe via iommu
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 via iommu
2021-09-21 23:56 ` Tian, Kevin
2021-09-22 0:55 ` Jason Gunthorpe via iommu
2021-09-22 1:07 ` Tian, Kevin
2021-09-22 12:31 ` Jason Gunthorpe via iommu
2021-09-22 3:22 ` Tian, Kevin
2021-09-22 12:50 ` Jason Gunthorpe via iommu
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 [this message]
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 via iommu
2021-09-21 23:10 ` Tian, Kevin
2021-09-22 0:53 ` Jason Gunthorpe via iommu
2021-09-22 0:59 ` Tian, Kevin
2021-09-22 9:23 ` Tian, Kevin
2021-09-22 12:22 ` Jason Gunthorpe via iommu
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 via iommu
2021-09-23 0:38 ` Tian, Kevin
2021-09-22 23:56 ` Jason Gunthorpe via iommu
2021-09-22 0:54 ` Tian, Kevin
2021-09-22 1:00 ` Jason Gunthorpe via iommu
2021-09-22 1:02 ` Tian, Kevin
2021-09-23 7:25 ` Eric Auger
2021-09-23 11:44 ` Jason Gunthorpe via iommu
2021-09-29 2:46 ` david
2021-09-29 12:22 ` Jason Gunthorpe via iommu
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 via iommu
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 via iommu
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 via iommu
2021-09-21 21:09 ` Alex Williamson
2021-09-21 21:58 ` Jason Gunthorpe via iommu
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 via iommu
2021-09-22 1:47 ` Tian, Kevin
2021-09-22 12:39 ` Jason Gunthorpe via iommu
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 via iommu
2021-09-27 13:00 ` Tian, Kevin
2021-09-27 13:09 ` Jason Gunthorpe via iommu
2021-09-27 15:09 ` Jason Gunthorpe via iommu
2021-09-28 7:30 ` Tian, Kevin
2021-09-28 11:57 ` Jason Gunthorpe via iommu
2021-09-28 13:35 ` Lu Baolu
2021-09-28 14:07 ` Jason Gunthorpe via iommu
2021-09-29 0:38 ` Tian, Kevin
2021-09-29 12:59 ` Jason Gunthorpe via iommu
2021-10-15 1:29 ` Tian, Kevin
2021-10-15 11:09 ` Jason Gunthorpe via iommu
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 via iommu
2021-09-30 3:09 ` David Gibson
2021-09-30 22:28 ` Jason Gunthorpe via iommu
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 via iommu
2021-10-15 9:21 ` Liu, Yi L
2021-09-29 5:25 ` David Gibson
2021-09-29 12:24 ` Jason Gunthorpe via iommu
2021-09-30 3:10 ` David Gibson
2021-10-01 12:43 ` Jason Gunthorpe via iommu
2021-10-07 1:23 ` David Gibson
2021-10-07 11:35 ` Jason Gunthorpe via iommu
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 via iommu
2021-09-22 21:01 ` Alex Williamson
2021-09-22 23:01 ` Jason Gunthorpe via iommu
2021-09-29 6:00 ` David Gibson
2021-09-29 6:41 ` Tian, Kevin
2021-09-29 12:28 ` Jason Gunthorpe via iommu
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 via iommu
2021-09-22 3:30 ` Tian, Kevin
2021-09-22 12:41 ` Jason Gunthorpe via iommu
2021-09-29 6:18 ` david
2021-09-22 21:24 ` Alex Williamson
2021-09-22 23:49 ` Jason Gunthorpe via iommu
2021-09-23 3:10 ` Tian, Kevin
2021-09-23 10:15 ` Jean-Philippe Brucker
2021-09-23 11:27 ` Jason Gunthorpe via iommu
2021-09-23 12:05 ` Tian, Kevin
2021-09-23 12:22 ` Jason Gunthorpe via iommu
2021-09-29 8:48 ` Tian, Kevin
2021-09-29 12:36 ` Jason Gunthorpe via iommu
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 via iommu
2021-09-23 11:36 ` Jason Gunthorpe via iommu
[not found] ` <BN9PR11MB5433409DF766AAEF1BB2CF258CA39@BN9PR11MB5433.namprd11.prod.outlook.com>
2021-09-23 3:38 ` Tian, Kevin
2021-09-23 11:42 ` Jason Gunthorpe via iommu
2021-09-30 9:35 ` Tian, Kevin
2021-09-30 22:23 ` Jason Gunthorpe via iommu
2021-10-01 3:30 ` hch
2021-10-14 9:11 ` Tian, Kevin
2021-10-14 15:42 ` Jason Gunthorpe via iommu
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 via iommu
2021-10-22 7:49 ` Jean-Philippe Brucker
2021-10-25 16:51 ` Jason Gunthorpe via iommu
2021-10-21 23:30 ` Jason Gunthorpe via iommu
2021-10-22 3:08 ` Tian, Kevin
2021-10-25 23:34 ` Jason Gunthorpe via iommu
2021-10-27 1:42 ` Tian, Kevin
2021-10-28 2:07 ` Tian, Kevin
2021-10-29 13:55 ` Jason Gunthorpe via iommu
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 via iommu
2021-09-22 3:40 ` Tian, Kevin
2021-09-22 14:09 ` Jason Gunthorpe via iommu
2021-09-23 9:14 ` Tian, Kevin
2021-09-23 12:06 ` Jason Gunthorpe via iommu
2021-09-23 12:22 ` Tian, Kevin
2021-09-23 12:31 ` Jason Gunthorpe via iommu
2021-09-23 12:45 ` Tian, Kevin
2021-09-23 13:01 ` Jason Gunthorpe via iommu
2021-09-23 13:20 ` Tian, Kevin
2021-09-23 13:30 ` Jason Gunthorpe via iommu
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 via iommu
2021-10-02 4:21 ` david
2021-10-02 12:25 ` Jason Gunthorpe via iommu
2021-10-11 5:37 ` david
2021-10-11 17:17 ` Jason Gunthorpe via iommu
2021-10-14 4:33 ` david
2021-10-14 15:06 ` Jason Gunthorpe via iommu
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 via iommu
2021-09-23 6:26 ` Liu, Yi L
2021-10-01 6:13 ` David Gibson
2021-10-01 12:22 ` Jason Gunthorpe via iommu
2021-10-11 6:02 ` David Gibson
2021-10-11 8:49 ` Jean-Philippe Brucker
2021-10-11 23:38 ` Jason Gunthorpe via iommu
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 via iommu
2021-10-14 4:53 ` David Gibson
2021-10-14 14:52 ` Jason Gunthorpe via iommu
2021-10-18 3:50 ` David Gibson
2021-10-18 17:42 ` Jason Gunthorpe via iommu
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 via iommu
2021-09-22 3:41 ` Tian, Kevin
2021-09-22 12:55 ` Jason Gunthorpe via iommu
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 via iommu
2021-10-25 5:14 ` David Gibson
2021-10-25 12:14 ` Jason Gunthorpe via iommu
2021-10-25 13:16 ` David Gibson
2021-10-25 23:36 ` Jason Gunthorpe via iommu
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 via iommu
2021-09-22 3:53 ` Tian, Kevin
2021-09-22 12:57 ` Jason Gunthorpe via iommu
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 via iommu
2021-09-22 3:56 ` Tian, Kevin
2021-09-22 12:58 ` Jason Gunthorpe via iommu
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 via iommu
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 via iommu
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 via iommu
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 via iommu
2021-09-22 3:25 ` Liu, Yi L
2021-10-25 6:28 [RFC 02/20] vfio: Add device class for /dev/vfio/devices Liu, Yi L
2021-10-25 12:53 ` Jason Gunthorpe via iommu
2021-10-29 9:47 ` Liu, Yi L
2021-11-01 12:50 ` Jason Gunthorpe via iommu
2021-11-02 9:53 ` Liu, Yi L
2021-11-03 13:25 ` Jason Gunthorpe via iommu
2021-11-11 12:32 ` Liu, Yi L
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