[PATCH 09/13] vfio/mdev: consolidate all the device_api sysfs into the core code

Christoph Hellwig
2022-06-28T05:17:32Z

From: Jason Gunthorpe <jgg@nvidia.com>

Every driver just emits a static string, simply feed it through the ops
and provide a standard sysfs show function.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
---
.../driver-api/vfio-mediated-device.rst | 2 +-
drivers/gpu/drm/i915/gvt/kvmgt.c | 9 +----
drivers/s390/cio/vfio_ccw_ops.c | 11 ++----
drivers/s390/crypto/vfio_ap_ops.c | 10 +-----
drivers/vfio/mdev/mdev_driver.c | 4 ++-
drivers/vfio/mdev/mdev_sysfs.c | 35 +++++++++++++------
include/linux/mdev.h | 7 ++--
samples/vfio-mdev/mbochs.c | 9 +----
samples/vfio-mdev/mdpy.c | 9 +----
samples/vfio-mdev/mtty.c | 10 +-----
10 files changed, 38 insertions(+), 68 deletions(-)

diff --git a/Documentation/driver-api/vfio-mediated-device.rst b/Documentation/driver-api/vfio-mediated-device.rst
index a4c3a4a168ec6..c30cb1092bdfb 100644
--- a/Documentation/driver-api/vfio-mediated-device.rst
+++ b/Documentation/driver-api/vfio-mediated-device.rst
@@ -204,7 +204,7 @@ Directories and files under the sysfs for Each Physical Device

* device_api

- This attribute should show which device API is being created, for example,
+ This attribute shows which device API is being created, for example,
"vfio-pci" for a PCI device.

* available_instances
diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
index 136f9c0df48b9..44a418d897377 100644
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -123,12 +123,6 @@ static ssize_t available_instances_show(struct mdev_type *mtype,
return sprintf(buf, "%u\n", type->avail_instance);
}

-static ssize_t device_api_show(struct mdev_type *mtype,
- struct mdev_type_attribute *attr, char *buf)
-{
- return sprintf(buf, "%s\n", VFIO_DEVICE_API_PCI_STRING);
-}
-
static ssize_t description_show(struct mdev_type *mtype,
struct mdev_type_attribute *attr, char *buf)
{
@@ -151,13 +145,11 @@ static ssize_t name_show(struct mdev_type *mtype,
}

static MDEV_TYPE_ATTR_RO(available_instances);
-static MDEV_TYPE_ATTR_RO(device_api);
static MDEV_TYPE_ATTR_RO(description);
static MDEV_TYPE_ATTR_RO(name);

static const struct attribute *gvt_type_attrs[] = {
&mdev_type_attr_available_instances.attr,
- &mdev_type_attr_device_api.attr,
&mdev_type_attr_description.attr,
&mdev_type_attr_name.attr,
NULL,
@@ -1587,6 +1579,7 @@ static void intel_vgpu_remove(struct mdev_device *mdev)
}

static struct mdev_driver intel_vgpu_mdev_driver = {
+ .device_api = VFIO_DEVICE_API_PCI_STRING,
.driver = {
.name = "intel_vgpu_mdev",
.owner = THIS_MODULE,
diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c
index 43d53736dfe3c..730d87a96a305 100644
--- a/drivers/s390/cio/vfio_ccw_ops.c
+++ b/drivers/s390/cio/vfio_ccw_ops.c
@@ -77,13 +77,6 @@ static ssize_t name_show(struct mdev_type *mtype,
}
static MDEV_TYPE_ATTR_RO(name);

-static ssize_t device_api_show(struct mdev_type *mtype,
- struct mdev_type_attribute *attr, char *buf)
-{
- return sprintf(buf, "%s\n", VFIO_DEVICE_API_CCW_STRING);
-}
-static MDEV_TYPE_ATTR_RO(device_api);
-
static ssize_t available_instances_show(struct mdev_type *mtype,
struct mdev_type_attribute *attr,
char *buf)
@@ -96,7 +89,6 @@ static MDEV_TYPE_ATTR_RO(available_instances);

static const struct attribute *mdev_types_attrs[] = {
&mdev_type_attr_name.attr,
- &mdev_type_attr_device_api.attr,
&mdev_type_attr_available_instances.attr,
NULL,
};
@@ -636,6 +628,7 @@ static const struct vfio_device_ops vfio_ccw_dev_ops = {
};

struct mdev_driver vfio_ccw_mdev_driver = {
+ .device_api = VFIO_DEVICE_API_CCW_STRING,
.driver = {
.name = "vfio_ccw_mdev",
.owner = THIS_MODULE,
@@ -648,7 +641,7 @@ struct mdev_driver vfio_ccw_mdev_driver = {

int vfio_ccw_mdev_reg(struct subchannel *sch)
{
- sprintf(sch->mdev_type.sysfs_name, "io");
+ strcat(sch->mdev_type.sysfs_name, "io");
sch->mdev_types[0] = &sch->mdev_type;
return mdev_register_parent(&sch->parent, &sch->dev,
&vfio_ccw_mdev_driver, sch->mdev_types,
diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index ff25858b2ebbe..da21fd60877fb 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -529,17 +529,8 @@ static ssize_t available_instances_show(struct mdev_type *mtype,

static MDEV_TYPE_ATTR_RO(available_instances);

-static ssize_t device_api_show(struct mdev_type *mtype,
- struct mdev_type_attribute *attr, char *buf)
-{
- return sprintf(buf, "%s\n", VFIO_DEVICE_API_AP_STRING);
-}
-
-static MDEV_TYPE_ATTR_RO(device_api);
-
static const struct attribute *vfio_ap_mdev_type_attrs[] = {
&mdev_type_attr_name.attr,
- &mdev_type_attr_device_api.attr,
&mdev_type_attr_available_instances.attr,
NULL,
};
@@ -1454,6 +1445,7 @@ static const struct vfio_device_ops vfio_ap_matrix_dev_ops = {
};

static struct mdev_driver vfio_ap_matrix_driver = {
+ .device_api = VFIO_DEVICE_API_AP_STRING,
.driver = {
.name = "vfio_ap_mdev",
.owner = THIS_MODULE,
diff --git a/drivers/vfio/mdev/mdev_driver.c b/drivers/vfio/mdev/mdev_driver.c
index 5b3c94f4fb13d..60e8b9f6474e8 100644
--- a/drivers/vfio/mdev/mdev_driver.c
+++ b/drivers/vfio/mdev/mdev_driver.c
@@ -55,8 +55,10 @@ struct bus_type mdev_bus_type = {
**/
int mdev_register_driver(struct mdev_driver *drv)
{
- if (!drv->types_attrs)
+ if (!drv->types_attrs || !drv->device_api)
return -EINVAL;
+
+ /* initialize common driver fields */
drv->driver.bus = &mdev_bus_type;
return driver_register(&drv->driver);
}
diff --git a/drivers/vfio/mdev/mdev_sysfs.c b/drivers/vfio/mdev/mdev_sysfs.c
index 80b2d546a3d98..89637bc85462a 100644
--- a/drivers/vfio/mdev/mdev_sysfs.c
+++ b/drivers/vfio/mdev/mdev_sysfs.c
@@ -72,9 +72,30 @@ static ssize_t create_store(struct mdev_type *mtype,

return count;
}
-
static MDEV_TYPE_ATTR_WO(create);

+static ssize_t device_api_show(struct mdev_type *mtype,
+ struct mdev_type_attribute *attr, char *buf)
+{
+ return sysfs_emit(buf, "%s\n", mtype->parent->mdev_driver->device_api);
+}
+static MDEV_TYPE_ATTR_RO(device_api);
+
+static struct attribute *mdev_types_core_attrs[] = {
+ &mdev_type_attr_create.attr,
+ &mdev_type_attr_device_api.attr,
+ NULL,
+};
+
+static struct attribute_group mdev_type_core_group = {
+ .attrs = mdev_types_core_attrs,
+};
+
+static const struct attribute_group *mdev_type_groups[] = {
+ &mdev_type_core_group,
+ NULL,
+};
+
static void mdev_type_release(struct kobject *kobj)
{
struct mdev_type *type = to_mdev_type(kobj);
@@ -86,8 +107,9 @@ static void mdev_type_release(struct kobject *kobj)
}

static struct kobj_type mdev_type_ktype = {
- .sysfs_ops = &mdev_type_sysfs_ops,
- .release = mdev_type_release,
+ .sysfs_ops = &mdev_type_sysfs_ops,
+ .release = mdev_type_release,
+ .default_groups = mdev_type_groups,
};

static int mdev_type_add(struct mdev_parent *parent, struct mdev_type *type)
@@ -107,10 +129,6 @@ static int mdev_type_add(struct mdev_parent *parent, struct mdev_type *type)
return ret;
}

- ret = sysfs_create_file(&type->kobj, &mdev_type_attr_create.attr);
- if (ret)
- goto attr_create_failed;
-
type->devices_kobj = kobject_create_and_add("devices", &type->kobj);
if (!type->devices_kobj) {
ret = -ENOMEM;
@@ -125,8 +143,6 @@ static int mdev_type_add(struct mdev_parent *parent, struct mdev_type *type)
attrs_failed:
kobject_put(type->devices_kobj);
attr_devices_failed:
- sysfs_remove_file(&type->kobj, &mdev_type_attr_create.attr);
-attr_create_failed:
kobject_del(&type->kobj);
kobject_put(&type->kobj);
return ret;
@@ -137,7 +153,6 @@ static void mdev_type_remove(struct mdev_type *type)
sysfs_remove_files(&type->kobj, type->parent->mdev_driver->types_attrs);

kobject_put(type->devices_kobj);
- sysfs_remove_file(&type->kobj, &mdev_type_attr_create.attr);
kobject_del(&type->kobj);
kobject_put(&type->kobj);
}
diff --git a/include/linux/mdev.h b/include/linux/mdev.h
index ecf964d34f2ca..ba48a6adea580 100644
--- a/include/linux/mdev.h
+++ b/include/linux/mdev.h
@@ -61,11 +61,6 @@ struct mdev_type_attribute {
size_t count);
};

-#define MDEV_TYPE_ATTR(_name, _mode, _show, _store) \
-struct mdev_type_attribute mdev_type_attr_##_name = \
- __ATTR(_name, _mode, _show, _store)
-#define MDEV_TYPE_ATTR_RW(_name) \
- struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_RW(_name)
#define MDEV_TYPE_ATTR_RO(_name) \
struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_RO(_name)
#define MDEV_TYPE_ATTR_WO(_name) \
@@ -73,12 +68,14 @@ struct mdev_type_attribute mdev_type_attr_##_name = \

/**
* struct mdev_driver - Mediated device driver
+ * @device_api: string to return for the device_api sysfs
* @probe: called when new device created
* @remove: called when device removed
* @types_attrs: attributes to the type kobjects.
* @driver: device driver structure
**/
struct mdev_driver {
+ const char *device_api;
int (*probe)(struct mdev_device *dev);
void (*remove)(struct mdev_device *dev);
const struct attribute * const *types_attrs;
diff --git a/samples/vfio-mdev/mbochs.c b/samples/vfio-mdev/mbochs.c
index 1069f561cb012..199846f01de92 100644
--- a/samples/vfio-mdev/mbochs.c
+++ b/samples/vfio-mdev/mbochs.c
@@ -1367,17 +1367,9 @@ static ssize_t available_instances_show(struct mdev_type *mtype,
}
static MDEV_TYPE_ATTR_RO(available_instances);

-static ssize_t device_api_show(struct mdev_type *mtype,
- struct mdev_type_attribute *attr, char *buf)
-{
- return sprintf(buf, "%s\n", VFIO_DEVICE_API_PCI_STRING);
-}
-static MDEV_TYPE_ATTR_RO(device_api);
-
static const struct attribute *mdev_types_attrs[] = {
&mdev_type_attr_name.attr,
&mdev_type_attr_description.attr,
- &mdev_type_attr_device_api.attr,
&mdev_type_attr_available_instances.attr,
NULL,
};
@@ -1391,6 +1383,7 @@ static const struct vfio_device_ops mbochs_dev_ops = {
};

static struct mdev_driver mbochs_driver = {
+ .device_api = VFIO_DEVICE_API_PCI_STRING,
.driver = {
.name = "mbochs",
.owner = THIS_MODULE,
diff --git a/samples/vfio-mdev/mdpy.c b/samples/vfio-mdev/mdpy.c
index 2052cc27b1c6d..b8d6eeff2033d 100644
--- a/samples/vfio-mdev/mdpy.c
+++ b/samples/vfio-mdev/mdpy.c
@@ -678,17 +678,9 @@ static ssize_t available_instances_show(struct mdev_type *mtype,
}
static MDEV_TYPE_ATTR_RO(available_instances);

-static ssize_t device_api_show(struct mdev_type *mtype,
- struct mdev_type_attribute *attr, char *buf)
-{
- return sprintf(buf, "%s\n", VFIO_DEVICE_API_PCI_STRING);
-}
-static MDEV_TYPE_ATTR_RO(device_api);
-
static const struct attribute *mdev_types_attrs[] = {
&mdev_type_attr_name.attr,
&mdev_type_attr_description.attr,
- &mdev_type_attr_device_api.attr,
&mdev_type_attr_available_instances.attr,
NULL,
};
@@ -701,6 +693,7 @@ static const struct vfio_device_ops mdpy_dev_ops = {
};

static struct mdev_driver mdpy_driver = {
+ .device_api = VFIO_DEVICE_API_PCI_STRING,
.driver = {
.name = "mdpy",
.owner = THIS_MODULE,
diff --git a/samples/vfio-mdev/mtty.c b/samples/vfio-mdev/mtty.c
index 029a19ef8ce7b..2a470424628af 100644
--- a/samples/vfio-mdev/mtty.c
+++ b/samples/vfio-mdev/mtty.c
@@ -1268,17 +1268,8 @@ static ssize_t available_instances_show(struct mdev_type *mtype,

static MDEV_TYPE_ATTR_RO(available_instances);

-static ssize_t device_api_show(struct mdev_type *mtype,
- struct mdev_type_attribute *attr, char *buf)
-{
- return sprintf(buf, "%s\n", VFIO_DEVICE_API_PCI_STRING);
-}
-
-static MDEV_TYPE_ATTR_RO(device_api);
-
static const struct attribute *mdev_types_attrs[] = {
&mdev_type_attr_name.attr,
- &mdev_type_attr_device_api.attr,
&mdev_type_attr_available_instances.attr,
NULL,
};
@@ -1291,6 +1282,7 @@ static const struct vfio_device_ops mtty_dev_ops = {
};

static struct mdev_driver mtty_driver = {
+ .device_api = VFIO_DEVICE_API_PCI_STRING,
.driver = {
.name = "mtty",
.owner = THIS_MODULE,
--
2.30.2