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
Signed-off-by: Jason Wang
---
.../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
diff --git a/Documentation/driver-api/vfio-mediated-device.rst
b/Documentation/driver-api/vfio-mediated-device.rst
index 6709413bee29..04d56884c357 100644
--- a/Documentation/driver-api/vfio-mediated-device.rst
+++ b/Documentation/driver-api/vfio-mediated-device.rst
@@ -152,15 +152,6 @@ callbacks per mdev parent device, per mdev type, or any
other categorization.
Vendor drivers are expected to be fully asynchronous in this respect or
provide their own internal resource protection.)
-The callbacks in the mdev_parent_ops structure are as follows:
-
-* open: open callback of mediated device
-* close: close callback of mediated device
-* ioctl: ioctl callback of mediated device
-* read : read emulation callback
-* write: write emulation callback
-* mmap: mmap emulation callback
-
A driver should use the mdev_parent_ops structure in the function call to
register itself with the mdev core driver::
@@ -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
+explicitly for the device that interacts with the mdev device directly
+through::
int mdev_set_class(struct mdev_device *mdev, u16 id);
+For the device that uses the mdev bus for its operation, the class
+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
==
diff --git a/MAINTAINERS b/MAINTAINERS
index cba1095547fd..f661d13344d6 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -17121,6 +17121,7 @@ S: Maintained
F: Documentation/driver-api/vfio-mediated-device.rst
F: drivers/vfio/mdev/
F: include/linux/mdev.h
+F: include/linux/mdev_vfio_ops.h
F: samples/vfio-mdev/
VFIO PLATFORM DRIVER
diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
index 6420f0dbd31b..662f3a672372 100644
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -42,6 +42,7 @@
#include
#include
#include
+#include
#include
#include
@@ -643,6 +644,8 @@ static void kvmgt_put_vfio_device(void *vgpu)
vfio_device_put(((struct intel_vgpu *)vgpu)->vdev.vfio_device);
}
+static const struct mdev_vfio_device_ops intel_vfio_vgpu_dev_ops;
+
static int intel_vgpu_create(struct kobject *kobj, struct mdev_device *mdev)
{
struct intel_vgpu *vgpu = NULL;
@@ -678,7 +681,7 @@ static int intel_vgpu_create(struct kobject *kobj, struct
mdev_device *mdev)
dev_name(mdev_dev(mdev)));
ret = 0;
- mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
+ mdev_set_vfio_ops(
