[PATCH 10/12] vfio/mdev: Remove mdev_parent_ops

Jason Gunthorpe
2021-04-23T23:03:26Z

The last useful member in this struct is the supported_type_groups, move
it to the mdev_driver and delete mdev_parent_ops.

Replace it with mdev_driver as an argument to mdev_register_device()

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
.../driver-api/vfio-mediated-device.rst | 36 +++++++------------
drivers/gpu/drm/i915/gvt/kvmgt.c | 8 ++---
drivers/s390/cio/vfio_ccw_ops.c | 7 +---
drivers/s390/crypto/vfio_ap_ops.c | 9 ++---
drivers/vfio/mdev/mdev_core.c | 13 +++----
drivers/vfio/mdev/mdev_driver.c | 2 +-
drivers/vfio/mdev/mdev_private.h | 2 +-
drivers/vfio/mdev/mdev_sysfs.c | 6 ++--
include/linux/mdev.h | 24 +++----------
samples/vfio-mdev/mbochs.c | 9 ++---
samples/vfio-mdev/mdpy.c | 9 ++---
samples/vfio-mdev/mtty.c | 9 ++---
12 files changed, 38 insertions(+), 96 deletions(-)

diff --git a/Documentation/driver-api/vfio-mediated-device.rst b/Documentation/driver-api/vfio-mediated-device.rst
index 5f866b17c93e69..b7cf357243d269 100644
--- a/Documentation/driver-api/vfio-mediated-device.rst
+++ b/Documentation/driver-api/vfio-mediated-device.rst
@@ -93,7 +93,7 @@ interfaces:
Registration Interface for a Mediated Bus Driver
------------------------------------------------

-The registration interface for a mediated bus driver provides the following
+The registration interface for a mediated device driver provides the following
structure to represent a mediated device's driver::

/*
@@ -105,6 +105,7 @@ structure to represent a mediated device's driver::
struct mdev_driver {
int (*probe) (struct mdev_device *dev);
void (*remove) (struct mdev_device *dev);
+ struct attribute_group **supported_type_groups;
struct device_driver driver;
};

@@ -119,35 +120,24 @@ to register and unregister itself with the core driver:

extern void mdev_unregister_driver(struct mdev_driver *drv);

-The mediated bus driver is responsible for adding mediated devices to the VFIO
-group when devices are bound to the driver and removing mediated devices from
-the VFIO when devices are unbound from the driver.
+The mediated bus driver's probe function should create a vfio_device on top of
+the mdev_device and connect it to an appropriate implementation of vfio_device_ops.

-
-Physical Device Driver Interface
---------------------------------
-
-The physical device driver interface provides the mdev_parent_ops[3] structure
-to define the APIs to manage work in the mediated core driver that is related
-to the physical device.
-
-The structures in the mdev_parent_ops structure are as follows:
-
-* dev_attr_groups: attributes of the parent device
-* mdev_attr_groups: attributes of the mediated device
-* supported_config: attributes to define supported configurations
-
-A driver should use the mdev_parent_ops structure in the function call to
-register itself with the mdev core driver::
+When a driver wants to add the GUID creation sysfs to an existing device it has
+probe'd to then it should call:

extern int mdev_register_device(struct device *dev,
- const struct mdev_parent_ops *ops);
+ struct mdev_driver *mdev_driver);
+
+This will provide the 'mdev_supported_types/XX/create' files which can then be used
+to trigger the creation of a mdev_device. The created mdev_device will be attached
+to the specified driver.

-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::
+When the driver needs to remove itself it calls:

extern void mdev_unregister_device(struct device *dev);

+Which will unbind and destroy all the created mdevs and remove the sysfs files.

Mediated Device Management Interface Through sysfs
==================================================
diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
index 85ef300087e091..02089efd15bb92 100644
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -1669,10 +1669,6 @@ static struct mdev_driver intel_vgpu_mdev_driver = {
.remove = intel_vgpu_remove,
};

-static struct mdev_parent_ops intel_vgpu_ops = {
- .device_driver = &intel_vgpu_mdev_driver,
-};
-
static int kvmgt_host_init(struct device *dev, void *gvt, const void *ops)
{
struct attribute_group **kvm_vgpu_type_groups;
@@ -1680,9 +1676,9 @@ static int kvmgt_host_init(struct device *dev, void *gvt, const void *ops)
intel_gvt_ops = ops;
if (!intel_gvt_ops->get_gvt_attrs(&kvm_vgpu_type_groups))
return -EFAULT;
- intel_vgpu_ops.supported_type_groups = kvm_vgpu_type_groups;
+ intel_vgpu_mdev_driver.supported_type_groups = kvm_vgpu_type_groups;

- return mdev_register_device(dev, &intel_vgpu_ops);
+ return mdev_register_device(dev, &intel_vgpu_mdev_driver);
}

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 0fcf46031d3821..161697529dcc41 100644
--- a/drivers/s390/cio/vfio_ccw_ops.c
+++ b/drivers/s390/cio/vfio_ccw_ops.c
@@ -655,17 +655,12 @@ struct mdev_driver vfio_ccw_mdev_driver = {
},
.probe = vfio_ccw_mdev_probe,
.remove = vfio_ccw_mdev_remove,
-};
-
-static const struct mdev_parent_ops vfio_ccw_mdev_ops = {
- .owner = THIS_MODULE,
- .device_driver = &vfio_ccw_mdev_driver,
.supported_type_groups = mdev_type_groups,
};

int vfio_ccw_mdev_reg(struct subchannel *sch)
{
- return mdev_register_device(&sch->dev, &vfio_ccw_mdev_ops);
+ return mdev_register_device(&sch->dev, &vfio_ccw_mdev_driver);
}

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 79872c857dd522..92789257c87639 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -1339,12 +1339,7 @@ static struct mdev_driver vfio_ap_matrix_driver = {
},
.probe = vfio_ap_mdev_probe,
.remove = vfio_ap_mdev_remove,
-};
-
-static const struct mdev_parent_ops vfio_ap_matrix_ops = {
- .owner = THIS_MODULE,
- .device_driver = &vfio_ap_matrix_driver,
- .supported_type_groups = vfio_ap_mdev_type_groups,
+ .supported_type_groups = vfio_ap_mdev_type_groups,
};

int vfio_ap_mdev_register(void)
@@ -1357,7 +1352,7 @@ int vfio_ap_mdev_register(void)
if (ret)
return ret;

- ret = mdev_register_device(&matrix_dev->device, &vfio_ap_matrix_ops);
+ ret = mdev_register_device(&matrix_dev->device, &vfio_ap_matrix_driver);
if (ret)
goto err_driver;
return 0;
diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
index f95d01b57fb168..7e918241de10cc 100644
--- a/drivers/vfio/mdev/mdev_core.c
+++ b/drivers/vfio/mdev/mdev_core.c
@@ -109,12 +109,12 @@ 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.
+ * @mdev_driver: Device driver to bind to the newly created mdev
*
* 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, struct mdev_driver *mdev_driver)
{
int ret;
struct mdev_parent *parent;
@@ -122,9 +122,7 @@ int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops)
char *envp[] = { env_string, NULL };

/* check for mandatory ops */
- if (!ops || !ops->supported_type_groups)
- return -EINVAL;
- if (!ops->device_driver)
+ if (!mdev_driver->supported_type_groups)
return -EINVAL;

dev = get_device(dev);
@@ -151,7 +149,7 @@ int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops)
init_rwsem(&parent->unreg_sem);

parent->dev = dev;
- parent->ops = ops;
+ parent->mdev_driver = mdev_driver;

if (!mdev_bus_compat_class) {
mdev_bus_compat_class = class_compat_register("mdev_bus");
@@ -257,7 +255,7 @@ static int mdev_bind_driver(struct mdev_device *mdev)
while (1) {
device_lock(&mdev->dev);
if (mdev->dev.driver ==
- &mdev->type->parent->ops->device_driver->driver) {
+ &mdev->type->parent->mdev_driver->driver) {
ret = 0;
goto out_unlock;
}
@@ -304,7 +302,6 @@ int mdev_device_create(struct mdev_type *type, const guid_t *uuid)
mdev->dev.parent = parent->dev;
mdev->dev.bus = &mdev_bus_type;
mdev->dev.release = mdev_device_release;
- mdev->dev.groups = parent->ops->mdev_attr_groups;
mdev->type = type;
/* Pairs with the put in mdev_device_release() */
kobject_get(&type->kobj);
diff --git a/drivers/vfio/mdev/mdev_driver.c b/drivers/vfio/mdev/mdev_driver.c
index 0012a9ee7cb0a4..12091e32afa396 100644
--- a/drivers/vfio/mdev/mdev_driver.c
+++ b/drivers/vfio/mdev/mdev_driver.c
@@ -75,7 +75,7 @@ static int mdev_match(struct device *dev, struct device_driver *drv)
{
struct mdev_device *mdev = to_mdev_device(dev);

- return drv == &mdev->type->parent->ops->device_driver->driver;
+ return drv == &mdev->type->parent->mdev_driver->driver;
}

struct bus_type mdev_bus_type = {
diff --git a/drivers/vfio/mdev/mdev_private.h b/drivers/vfio/mdev/mdev_private.h
index a656cfe0346c33..839567d059a07d 100644
--- a/drivers/vfio/mdev/mdev_private.h
+++ b/drivers/vfio/mdev/mdev_private.h
@@ -15,7 +15,7 @@ void mdev_bus_unregister(void);

struct mdev_parent {
struct device *dev;
- const struct mdev_parent_ops *ops;
+ const struct mdev_driver *mdev_driver;
struct kref ref;
struct list_head next;
struct kset *mdev_types_kset;
diff --git a/drivers/vfio/mdev/mdev_sysfs.c b/drivers/vfio/mdev/mdev_sysfs.c
index 66eef08833a4ef..5a3873d1a275ae 100644
--- a/drivers/vfio/mdev/mdev_sysfs.c
+++ b/drivers/vfio/mdev/mdev_sysfs.c
@@ -97,7 +97,7 @@ static struct mdev_type *add_mdev_supported_type(struct mdev_parent *parent,
{
struct mdev_type *type;
struct attribute_group *group =
- parent->ops->supported_type_groups[type_group_id];
+ parent->mdev_driver->supported_type_groups[type_group_id];
int ret;

if (!group->name) {
@@ -154,7 +154,7 @@ static struct mdev_type *add_mdev_supported_type(struct mdev_parent *parent,
static void remove_mdev_supported_type(struct mdev_type *type)
{
struct attribute_group *group =
- type->parent->ops->supported_type_groups[type->type_group_id];
+ type->parent->mdev_driver->supported_type_groups[type->type_group_id];

sysfs_remove_files(&type->kobj,
(const struct attribute **)group->attrs);
@@ -168,7 +168,7 @@ static int add_mdev_supported_type_groups(struct mdev_parent *parent)
{
int i;

- for (i = 0; parent->ops->supported_type_groups[i]; i++) {
+ for (i = 0; parent->mdev_driver->supported_type_groups[i]; i++) {
struct mdev_type *type;

type = add_mdev_supported_type(parent, i);
diff --git a/include/linux/mdev.h b/include/linux/mdev.h
index fd9fe1dcf0e230..af807c77c1e0f5 100644
--- a/include/linux/mdev.h
+++ b/include/linux/mdev.h
@@ -51,25 +51,6 @@ unsigned int mdev_get_type_group_id(struct mdev_device *mdev);
unsigned int mtype_get_type_group_id(struct mdev_type *mtype);
struct device *mtype_get_parent_dev(struct mdev_type *mtype);

-/**
- * struct mdev_parent_ops - Structure to be registered for each parent device to
- * register the device to mdev module.
- *
- * @owner: The module owner.
- * @device_driver: Which device driver to probe() on newly created devices
- * @mdev_attr_groups: Attributes of the mediated device.
- * @supported_type_groups: Attributes to define supported types. It is mandatory
- * to provide supported types.
- * Parent device that support mediated device should be registered with mdev
- * module with mdev_parent_ops structure.
- **/
-struct mdev_parent_ops {
- struct module *owner;
- struct mdev_driver *device_driver;
- const struct attribute_group **mdev_attr_groups;
- struct attribute_group **supported_type_groups;
-};
-
/* interface for exporting mdev supported type attributes */
struct mdev_type_attribute {
struct attribute attr;
@@ -94,12 +75,15 @@ struct mdev_type_attribute mdev_type_attr_##_name = \
* struct mdev_driver - Mediated device driver
* @probe: called when new device created
* @remove: called when device removed
+ * @supported_type_groups: Attributes to define supported types. It is mandatory
+ * to provide supported types.
* @driver: device driver structure
*
**/
struct mdev_driver {
int (*probe)(struct mdev_device *dev);
void (*remove)(struct mdev_device *dev);
+ struct attribute_group **supported_type_groups;
struct device_driver driver;
};

@@ -118,7 +102,7 @@ static inline 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_device(struct device *dev, struct mdev_driver *mdev_driver);
void mdev_unregister_device(struct device *dev);

int mdev_register_driver(struct mdev_driver *drv);
diff --git a/samples/vfio-mdev/mbochs.c b/samples/vfio-mdev/mbochs.c
index e18821a8a6beb8..c76ceec584b41b 100644
--- a/samples/vfio-mdev/mbochs.c
+++ b/samples/vfio-mdev/mbochs.c
@@ -1418,12 +1418,7 @@ static struct mdev_driver mbochs_driver = {
},
.probe = mbochs_probe,
.remove = mbochs_remove,
-};
-
-static const struct mdev_parent_ops mdev_fops = {
- .owner = THIS_MODULE,
- .device_driver = &mbochs_driver,
- .supported_type_groups = mdev_type_groups,
+ .supported_type_groups = mdev_type_groups,
};

static const struct file_operations vd_fops = {
@@ -1466,7 +1461,7 @@ static int __init mbochs_dev_init(void)
if (ret)
goto err_class;

- ret = mdev_register_device(&mbochs_dev, &mdev_fops);
+ ret = mdev_register_device(&mbochs_dev, &mbochs_driver);
if (ret)
goto err_device;

diff --git a/samples/vfio-mdev/mdpy.c b/samples/vfio-mdev/mdpy.c
index 82638de333330d..c22b2c808d132d 100644
--- a/samples/vfio-mdev/mdpy.c
+++ b/samples/vfio-mdev/mdpy.c
@@ -735,12 +735,7 @@ static struct mdev_driver mdpy_driver = {
},
.probe = mdpy_probe,
.remove = mdpy_remove,
-};
-
-static const struct mdev_parent_ops mdev_fops = {
- .owner = THIS_MODULE,
- .device_driver = &mdpy_driver,
- .supported_type_groups = mdev_type_groups,
+ .supported_type_groups = mdev_type_groups,
};

static const struct file_operations vd_fops = {
@@ -783,7 +778,7 @@ static int __init mdpy_dev_init(void)
if (ret)
goto err_class;

- ret = mdev_register_device(&mdpy_dev, &mdev_fops);
+ ret = mdev_register_device(&mdpy_dev, &mdpy_driver);
if (ret)
goto err_device;

diff --git a/samples/vfio-mdev/mtty.c b/samples/vfio-mdev/mtty.c
index 31eec76bc553ce..87f5ba12a230e3 100644
--- a/samples/vfio-mdev/mtty.c
+++ b/samples/vfio-mdev/mtty.c
@@ -1308,12 +1308,7 @@ static struct mdev_driver mtty_driver = {
},
.probe = mtty_probe,
.remove = mtty_remove,
-};
-
-static const struct mdev_parent_ops mdev_fops = {
- .owner = THIS_MODULE,
- .device_driver = &mtty_driver,
- .supported_type_groups = mdev_type_groups,
+ .supported_type_groups = mdev_type_groups,
};

static void mtty_device_release(struct device *dev)
@@ -1364,7 +1359,7 @@ static int __init mtty_dev_init(void)
if (ret)
goto err_class;

- ret = mdev_register_device(&mtty_dev.dev, &mdev_fops);
+ ret = mdev_register_device(&mtty_dev.dev, &mtty_driver);
if (ret)
goto err_device;

--
2.31.1