On Tue, 5 Nov 2019 10:44:18 -0700 Alex Williamson <alex.williamson@xxxxxxxxxx> wrote: > On Tue, 5 Nov 2019 17:50:25 +0100 > Cornelia Huck <cohuck@xxxxxxxxxx> wrote: > > > On Tue, 5 Nov 2019 17:32:37 +0800 > > Jason Wang <jasowang@xxxxxxxxxx> wrote: > > > > > Currently, except for the create and remove, the rest of > > > mdev_parent_ops is designed for vfio-mdev driver only and may not help > > > for kernel mdev driver. With the help of class id, this patch > > > introduces device specific callbacks inside mdev_device > > > structure. This allows different set of callback to be used by > > > vfio-mdev and virtio-mdev. > > > > > > Reviewed-by: Parav Pandit <parav@xxxxxxxxxxxx> > > > Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx> > > > --- > > > .../driver-api/vfio-mediated-device.rst | 35 +++++++++---- > > > MAINTAINERS | 1 + > > > drivers/gpu/drm/i915/gvt/kvmgt.c | 18 ++++--- > > > drivers/s390/cio/vfio_ccw_ops.c | 18 ++++--- > > > drivers/s390/crypto/vfio_ap_ops.c | 14 +++-- > > > drivers/vfio/mdev/mdev_core.c | 24 ++++++++- > > > drivers/vfio/mdev/mdev_private.h | 5 ++ > > > drivers/vfio/mdev/vfio_mdev.c | 37 ++++++------- > > > include/linux/mdev.h | 43 ++++----------- > > > include/linux/mdev_vfio_ops.h | 52 +++++++++++++++++++ > > > samples/vfio-mdev/mbochs.c | 20 ++++--- > > > samples/vfio-mdev/mdpy.c | 20 ++++--- > > > samples/vfio-mdev/mtty.c | 18 ++++--- > > > 13 files changed, 206 insertions(+), 99 deletions(-) > > > create mode 100644 include/linux/mdev_vfio_ops.h > > > > > > > (...) > > > > > @@ -172,10 +163,34 @@ that a driver should use to unregister itself with the mdev core driver:: > > > > > > extern void mdev_unregister_device(struct device *dev); > > > > > > -It is also required to specify the class_id in create() callback through:: > > > +As multiple types of mediated devices may be supported, class id needs > > > +to be specified in the create callback(). This could be done > > > > The brackets should probably go behind 'create'? > > > > > +explicitly for the device that does not use on mdev bus for its > > > > "for devices that do not use the mdev bus" ? > > > > But why wouldn't they? I feel like I've missed some discussion here :/ > > The device ops provide a route through mdev-core for known callbacks, > which is primarily useful when we have 1:N relation between mdev bus > driver and vendor drivers. The obvious example here is vfio-mdev, > where we have GVT-g, vfio-ap, vfio-ccw, NVIDIA GRID, and various sample > drivers all advertising vfio-mdev support via their class id. However, > if we have a tightly coupled vendor driver and mdev bus driver, as the > mlx5 support that Parav is developing, the claim is that they prefer > not to expose any device ops and intend to interact directly with the > mdev device. At least that's my understanding. Thanks, > > Alex Ah, ok. So maybe use the phrasing "devices that interact with the mdev device directly" vs "devices that use device-specific ops" instead? Not a strong critique, though. > > > > +operation through: > > > > > > int mdev_set_class(struct mdev_device *mdev, u16 id); > > > > > > +For the device that uses on the mdev bus for its operation, the > > > class > > > > "For devices that use the mdev bus..." > > > > But same comment as above. > > > > > +should provide helper function to set class id and device > > > specific +ops. E.g for vfio-mdev devices, the function to be > > > called is:: + > > > + int mdev_set_vfio_ops(struct mdev_device *mdev, > > > + const struct mdev_vfio_device_ops > > > *vfio_ops); + > > > +The class id (set by this function to MDEV_CLASS_ID_VFIO) is > > > used to +match a device with an mdev driver via its id table. The > > > device +specific callbacks (specified in *vfio_ops) are > > > obtainable via +mdev_get_vfio_ops() (for use by the mdev bus > > > driver). A vfio-mdev +device (class id MDEV_CLASS_ID_VFIO) uses > > > the following +device-specific ops: > > > + > > > +* open: open callback of vfio mediated device > > > +* close: close callback of vfio mediated device > > > +* ioctl: ioctl callback of vfio mediated device > > > +* read : read emulation callback > > > +* write: write emulation callback > > > +* mmap: mmap emulation callback > > > + > > > Mediated Device Management Interface Through sysfs > > > ================================================== > > > > Otherwise, looks good. > _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
