On 10/29/2016 10:00 AM, Jike Song wrote:
> On 10/27/2016 05:29 AM, Kirti Wankhede wrote:
>> +int mdev_register_device(struct device *dev, const struct parent_ops *ops)
>> +{
>> + int ret;
>> + struct parent_device *parent;
>> +
>> + /* check for mandatory ops */
>> + if (!ops || !ops->create || !ops->remove || !ops->supported_type_groups)
>> + return -EINVAL;
>> +
>> + dev = get_device(dev);
>> + if (!dev)
>> + return -EINVAL;
>> +
>> + mutex_lock(&parent_list_lock);
>> +
>> + /* Check for duplicate */
>> + parent = __find_parent_device(dev);
>> + if (parent) {
>> + ret = -EEXIST;
>> + goto add_dev_err;
>> + }
>> +
>> + parent = kzalloc(sizeof(*parent), GFP_KERNEL);
>> + if (!parent) {
>> + ret = -ENOMEM;
>> + goto add_dev_err;
>> + }
>> +
>> + kref_init(&parent->ref);
>> + mutex_init(&parent->lock);
>> +
>> + parent->dev = dev;
>> + parent->ops = ops;
>> +
>> + ret = parent_create_sysfs_files(parent);
>> + if (ret) {
>> + mutex_unlock(&parent_list_lock);
>> + mdev_put_parent(parent);
>> + return ret;
>> + }
>> +
>> + ret = class_compat_create_link(mdev_bus_compat_class, dev, NULL);
>> + if (ret)
>> + dev_warn(dev, "Failed to create compatibility class link\n");
>> +
>
> Hi Kirti,
>
> Like I replied to previous version:
>
> http://www.spinics.net/lists/kvm/msg139331.html
>
Hi Jike,
I saw your reply but by that time v10 version of patch series was out
for review.
> You can always check if mdev_bus_compat_class already registered
> here, and register it if not yet. Same logic should be adopted to
> mdev_init.
>
> Current implementation will simply panic if configured as builtin,
> which is rare but far from impossible.
>
Can you verify attached patch with v10 patch-set whether this works for you?
I'll incorporate this change in my next version.
Thanks,
Kirti
From: Kirti Wankhede <kwankh...@nvidia.com>
Date: Sat, 29 Oct 2016 15:12:01 +0530
Subject: [PATCH 1/1] Register mdev_bus class on first mdev_device_register
Signed-off-by: Kirti Wankhede <kwankh...@nvidia.com>
Signed-off-by: Neo Jia <c...@nvidia.com>
---
drivers/vfio/mdev/mdev_core.c | 30 +++++++++++++++++-------------
1 file changed, 17 insertions(+), 13 deletions(-)
diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
index 9d8fa5c91c2e..54c59f325336 100644
--- a/drivers/vfio/mdev/mdev_core.c
+++ b/drivers/vfio/mdev/mdev_core.c
@@ -187,13 +187,18 @@ int mdev_register_device(struct device *dev, const struct
parent_ops *ops)
parent->dev = dev;
parent->ops = ops;
- ret = parent_create_sysfs_files(parent);
- if (ret) {
- mutex_unlock(&parent_list_lock);
- mdev_put_parent(parent);
- return ret;
+ if (!mdev_bus_compat_class) {
+ mdev_bus_compat_class = class_compat_register("mdev_bus");
+ if (!mdev_bus_compat_class) {
+ ret = -ENOMEM;
+ goto add_dev_err;
+ }
}
+ ret = parent_create_sysfs_files(parent);
+ if (ret)
+ goto add_dev_err;
+
ret = class_compat_create_link(mdev_bus_compat_class, dev, NULL);
if (ret)
dev_warn(dev, "Failed to create compatibility class link\n");
@@ -206,7 +211,10 @@ int mdev_register_device(struct device *dev, const struct
parent_ops *ops)
add_dev_err:
mutex_unlock(&parent_list_lock);
- put_device(dev);
+ if (parent)
+ mdev_put_parent(parent);
+ else
+ put_device(dev);
return ret;
}
EXPORT_SYMBOL(mdev_register_device);
@@ -354,12 +362,6 @@ static int __init mdev_init(void)
return ret;
}
- mdev_bus_compat_class = class_compat_register("mdev_bus");
- if (!mdev_bus_compat_class) {
- mdev_bus_unregister();
- return -ENOMEM;
- }
-
/*
* Attempt to load known vfio_mdev. This gives us a working environment
* without the user needing to explicitly load vfio_mdev driver.
@@ -371,7 +373,9 @@ static int __init mdev_init(void)
static void __exit mdev_exit(void)
{
- class_compat_unregister(mdev_bus_compat_class);
+ if (mdev_bus_compat_class)
+ class_compat_unregister(mdev_bus_compat_class);
+
mdev_bus_unregister();
}
--
2.7.0
