vfio/mdev: consolidate all the device_api sysfs into the core code

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: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Link: https://lore.kernel.org/r/20220923092652.100656-11-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

diff --git a/Documentation/driver-api/vfio-mediated-device.rst b/Documentation/driver-api/vfio-mediated-device.rst
index 7b660f3fa2c9249488fe2e3fd8c34b78d51787ce..b0c29e37f61b44ba1f131805a69ed3d6b9929cf4 100644 (file)
--- a/Documentation/driver-api/vfio-mediated-device.rst
+++ b/Documentation/driver-api/vfio-mediated-device.rst
@@ -202,7 +202,7 @@ 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 2265dd867956f373c4d0ee8edc8f1f2f562b87bc..0f70886a63e9267641f6488b83eb75eb3bd22010 100644 (file)
--- 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,
@@ -1550,6 +1542,7 @@ 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 3db6251b311433a966ad8e56cf8d31d7a1a08a7f..4c7b181519228a45762cb80e36753825aca753fb 100644 (file)
--- a/drivers/s390/cio/vfio_ccw_ops.c
+++ b/drivers/s390/cio/vfio_ccw_ops.c
@@ -51,13 +51,6 @@ 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)
@@ -70,7 +63,6 @@ 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,
 };
@@ -628,6 +620,7 @@ 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,

diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index 24d131c502ca3149eccb87ec5d3d6c879d4235e2..d440acfbb261e90780e859ed5756e9d992bb7c79 100644 (file)
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -808,17 +808,8 @@ 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,
 };
@@ -1799,6 +1790,7 @@ 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 5b3c94f4fb13db34e9d1a1577fce8eb0ef3a4950..60e8b9f6474e8d6e1b8d6742c87b8afffac1fd1d 100644 (file)
--- 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 38b4c2466ec43d5c45578cb93099fe715fe7aba8..60fc52ff92448ccee79a940a82b655bf12e7d76c 100644 (file)
--- 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);
@@ -85,8 +106,9 @@ 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)
@@ -106,10 +128,6 @@ 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;
@@ -124,8 +142,6 @@ 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;
@@ -136,7 +152,6 @@ 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 e445f809ceca3faba745b83b748aabb8f862bf9b..af1ff0165b8d3bdde258d6379dc4491ce20e6e99 100644 (file)
--- 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 4d0839cb51943d4cdec728f038d2f8162965251f..a2fc13fade7571521f1bc2a317cae2f31951511a 100644 (file)
--- a/samples/vfio-mdev/mbochs.c
+++ b/samples/vfio-mdev/mbochs.c
@@ -1384,17 +1384,9 @@ 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,
 };
@@ -1410,6 +1402,7 @@ 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 4a341f4849e73a07df114083bc8884d2890e23cb..f9069ed2750fa9e8ee52dd544e7ae25cdc356420 100644 (file)
--- a/samples/vfio-mdev/mdpy.c
+++ b/samples/vfio-mdev/mdpy.c
@@ -689,17 +689,9 @@ 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,
 };
@@ -714,6 +706,7 @@ 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 814a7f98738a261b2860e03cbd602d8f60d734e3..064e71b28dd1905f7cd5ea7ff162d9339b9c8c49 100644 (file)
--- a/samples/vfio-mdev/mtty.c
+++ b/samples/vfio-mdev/mtty.c
@@ -1277,17 +1277,8 @@ 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,
 };
@@ -1302,6 +1293,7 @@ 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,