Mdev bus only supports vfio driver right now, so it doesn't implement match method. But in the future, we may add drivers other than vfio, one example is virtio-mdev[1] driver. This means we need to add device class id support in bus match method to pair the mdev device and mdev driver correctly.
So this patch adds id_table to mdev_driver and class_id for mdev parent with the match method for mdev bus.
Signed-off-by: Jason Wang jasowang@redhat.com --- Documentation/driver-api/vfio-mediated-device.rst | 7 +++++-- drivers/gpu/drm/i915/gvt/kvmgt.c | 2 +- drivers/s390/cio/vfio_ccw_ops.c | 2 +- drivers/s390/crypto/vfio_ap_ops.c | 3 ++- drivers/vfio/mdev/mdev_core.c | 14 ++++++++++++-- drivers/vfio/mdev/mdev_driver.c | 14 ++++++++++++++ drivers/vfio/mdev/mdev_private.h | 1 + drivers/vfio/mdev/vfio_mdev.c | 6 ++++++ include/linux/mdev.h | 7 ++++++- include/linux/mod_devicetable.h | 8 ++++++++ samples/vfio-mdev/mbochs.c | 2 +- samples/vfio-mdev/mdpy.c | 2 +- samples/vfio-mdev/mtty.c | 2 +- 13 files changed, 59 insertions(+), 11 deletions(-)
diff --git a/Documentation/driver-api/vfio-mediated-device.rst b/Documentation/driver-api/vfio-mediated-device.rst index 25eb7d5b834b..0e052072e1d8 100644 --- a/Documentation/driver-api/vfio-mediated-device.rst +++ b/Documentation/driver-api/vfio-mediated-device.rst @@ -102,12 +102,14 @@ structure to represent a mediated device's driver:: * @probe: called when new device created * @remove: called when device removed * @driver: device driver structure + * @id_table: the ids serviced by this driver. */ struct mdev_driver { const char *name; int (*probe) (struct device *dev); void (*remove) (struct device *dev); struct device_driver driver; + const struct mdev_class_id *id_table; };
A mediated bus driver for mdev should use this structure in the function calls @@ -116,7 +118,7 @@ to register and unregister itself with the core driver: * Register::
extern int mdev_register_driver(struct mdev_driver *drv, - struct module *owner); + struct module *owner);
* Unregister::
@@ -163,7 +165,8 @@ A driver should use the mdev_parent_ops structure in the function call to register itself with the mdev core driver::
extern int mdev_register_device(struct device *dev, - const struct mdev_parent_ops *ops); + const struct mdev_parent_ops *ops, + u8 class_id);
However, the mdev_parent_ops structure is not required in the function call that a driver should use to unregister itself with the mdev core driver:: diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c index 23aa3e50cbf8..19d51a35f019 100644 --- a/drivers/gpu/drm/i915/gvt/kvmgt.c +++ b/drivers/gpu/drm/i915/gvt/kvmgt.c @@ -1625,7 +1625,7 @@ static int kvmgt_host_init(struct device *dev, void *gvt, const void *ops) return -EFAULT; intel_vgpu_ops.supported_type_groups = kvm_vgpu_type_groups;
- return mdev_register_device(dev, &intel_vgpu_ops); + return mdev_register_vfio_device(dev, &intel_vgpu_ops); }
static void kvmgt_host_exit(struct device *dev) diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c index f0d71ab77c50..246ff0f80944 100644 --- a/drivers/s390/cio/vfio_ccw_ops.c +++ b/drivers/s390/cio/vfio_ccw_ops.c @@ -588,7 +588,7 @@ static const struct mdev_parent_ops vfio_ccw_mdev_ops = {
int vfio_ccw_mdev_reg(struct subchannel *sch) { - return mdev_register_device(&sch->dev, &vfio_ccw_mdev_ops); + return mdev_register_vfio_device(&sch->dev, &vfio_ccw_mdev_ops); }
void vfio_ccw_mdev_unreg(struct subchannel *sch) diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c index 5c0f53c6dde7..7487fc39d2c5 100644 --- a/drivers/s390/crypto/vfio_ap_ops.c +++ b/drivers/s390/crypto/vfio_ap_ops.c @@ -1295,7 +1295,8 @@ int vfio_ap_mdev_register(void) { atomic_set(&matrix_dev->available_instances, MAX_ZDEV_ENTRIES_EXT);
- return mdev_register_device(&matrix_dev->device, &vfio_ap_matrix_ops); + return mdev_register_vfio_device(&matrix_dev->device, + &vfio_ap_matrix_ops); }
void vfio_ap_mdev_unregister(void) diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c index b558d4cfd082..a02c256a3514 100644 --- a/drivers/vfio/mdev/mdev_core.c +++ b/drivers/vfio/mdev/mdev_core.c @@ -135,11 +135,14 @@ static int mdev_device_remove_cb(struct device *dev, void *data) * mdev_register_device : Register a device * @dev: device structure representing parent device. * @ops: Parent device operation structure to be registered. + * @id: device id. * * Add device to list of registered parent devices. * Returns a negative value on error, otherwise 0. */ -int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops) +int mdev_register_device(struct device *dev, + const struct mdev_parent_ops *ops, + u8 class_id) { int ret; struct mdev_parent *parent; @@ -175,6 +178,7 @@ int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops)
parent->dev = dev; parent->ops = ops; + parent->class_id = class_id;
if (!mdev_bus_compat_class) { mdev_bus_compat_class = class_compat_register("mdev_bus"); @@ -208,7 +212,13 @@ int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops) put_device(dev); return ret; } -EXPORT_SYMBOL(mdev_register_device); + +int mdev_register_vfio_device(struct device *dev, + const struct mdev_parent_ops *ops) +{ + return mdev_register_device(dev, ops, MDEV_ID_VFIO); +} +EXPORT_SYMBOL(mdev_register_vfio_device);
/* * mdev_unregister_device : Unregister a parent device diff --git a/drivers/vfio/mdev/mdev_driver.c b/drivers/vfio/mdev/mdev_driver.c index 0d3223aee20b..b70bbebc9dd3 100644 --- a/drivers/vfio/mdev/mdev_driver.c +++ b/drivers/vfio/mdev/mdev_driver.c @@ -69,8 +69,22 @@ static int mdev_remove(struct device *dev) return 0; }
+static int mdev_match(struct device *dev, struct device_driver *drv) +{ + unsigned int i; + struct mdev_device *mdev = to_mdev_device(dev); + struct mdev_driver *mdrv = to_mdev_driver(drv); + const struct mdev_class_id *ids = mdrv->id_table; + + for (i = 0; ids[i].id; i++) + if (ids[i].id == mdev->parent->class_id) + return 1; + return 0; +} + struct bus_type mdev_bus_type = { .name = "mdev", + .match = mdev_match, .probe = mdev_probe, .remove = mdev_remove, }; diff --git a/drivers/vfio/mdev/mdev_private.h b/drivers/vfio/mdev/mdev_private.h index 7d922950caaf..e58b07c866b1 100644 --- a/drivers/vfio/mdev/mdev_private.h +++ b/drivers/vfio/mdev/mdev_private.h @@ -22,6 +22,7 @@ struct mdev_parent { struct list_head type_list; /* Synchronize device creation/removal with parent unregistration */ struct rw_semaphore unreg_sem; + u8 class_id; };
struct mdev_device { diff --git a/drivers/vfio/mdev/vfio_mdev.c b/drivers/vfio/mdev/vfio_mdev.c index 30964a4e0a28..fd2a4d9a3f26 100644 --- a/drivers/vfio/mdev/vfio_mdev.c +++ b/drivers/vfio/mdev/vfio_mdev.c @@ -120,10 +120,16 @@ static void vfio_mdev_remove(struct device *dev) vfio_del_group_dev(dev); }
+static struct mdev_class_id id_table[] = { + { MDEV_ID_VFIO }, + { 0 }, +}; + static struct mdev_driver vfio_mdev_driver = { .name = "vfio_mdev", .probe = vfio_mdev_probe, .remove = vfio_mdev_remove, + .id_table = id_table, };
static int __init vfio_mdev_init(void) diff --git a/include/linux/mdev.h b/include/linux/mdev.h index 0ce30ca78db0..3ebae310f599 100644 --- a/include/linux/mdev.h +++ b/include/linux/mdev.h @@ -118,6 +118,7 @@ struct mdev_type_attribute mdev_type_attr_##_name = \ * @probe: called when new device created * @remove: called when device removed * @driver: device driver structure + * @id_table: the ids serviced by this driver. * **/ struct mdev_driver { @@ -125,6 +126,7 @@ struct mdev_driver { int (*probe)(struct device *dev); void (*remove)(struct device *dev); struct device_driver driver; + const struct mdev_class_id *id_table; };
#define to_mdev_driver(drv) container_of(drv, struct mdev_driver, driver) @@ -135,7 +137,8 @@ const guid_t *mdev_uuid(struct mdev_device *mdev);
extern struct bus_type mdev_bus_type;
-int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops); +int mdev_register_vfio_device(struct device *dev, + const struct mdev_parent_ops *ops); void mdev_unregister_device(struct device *dev);
int mdev_register_driver(struct mdev_driver *drv, struct module *owner); @@ -145,4 +148,6 @@ struct device *mdev_parent_dev(struct mdev_device *mdev); struct device *mdev_dev(struct mdev_device *mdev); struct mdev_device *mdev_from_dev(struct device *dev);
+#define MDEV_ID_VFIO 1 /* VFIO device */ + #endif /* MDEV_H */ diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h index 5714fd35a83c..f32c6e44fb1a 100644 --- a/include/linux/mod_devicetable.h +++ b/include/linux/mod_devicetable.h @@ -821,4 +821,12 @@ struct wmi_device_id { const void *context; };
+/** + * struct mdev_class_id - MDEV device class identifier + * @id: Used to identify a specific class of device, e.g vfio-mdev device. + */ +struct mdev_class_id { + __u16 id; +}; + #endif /* LINUX_MOD_DEVICETABLE_H */ diff --git a/samples/vfio-mdev/mbochs.c b/samples/vfio-mdev/mbochs.c index ac5c8c17b1ff..71a4469be85d 100644 --- a/samples/vfio-mdev/mbochs.c +++ b/samples/vfio-mdev/mbochs.c @@ -1468,7 +1468,7 @@ static int __init mbochs_dev_init(void) if (ret) goto failed2;
- ret = mdev_register_device(&mbochs_dev, &mdev_fops); + ret = mdev_register_vfio_device(&mbochs_dev, &mdev_fops); if (ret) goto failed3;
diff --git a/samples/vfio-mdev/mdpy.c b/samples/vfio-mdev/mdpy.c index cc86bf6566e4..d3029dd27d91 100644 --- a/samples/vfio-mdev/mdpy.c +++ b/samples/vfio-mdev/mdpy.c @@ -775,7 +775,7 @@ static int __init mdpy_dev_init(void) if (ret) goto failed2;
- ret = mdev_register_device(&mdpy_dev, &mdev_fops); + ret = mdev_register_vfio_device(&mdpy_dev, &mdev_fops); if (ret) goto failed3;
diff --git a/samples/vfio-mdev/mtty.c b/samples/vfio-mdev/mtty.c index 92e770a06ea2..744c88a6b22c 100644 --- a/samples/vfio-mdev/mtty.c +++ b/samples/vfio-mdev/mtty.c @@ -1468,7 +1468,7 @@ static int __init mtty_dev_init(void) if (ret) goto failed2;
- ret = mdev_register_device(&mtty_dev.dev, &mdev_fops); + ret = mdev_register_vfio_device(&mtty_dev.dev, &mdev_fops); if (ret) goto failed3;