From: Jason Gunthorpe <jgg@nvidia.com>
To: Alex Williamson <alex.williamson@redhat.com>,
Cornelia Huck <cohuck@redhat.com>,
kvm@vger.kernel.org, Kirti Wankhede <kwankhede@nvidia.com>
Cc: "Raj, Ashok" <ashok.raj@intel.com>,
Dan Williams <dan.j.williams@intel.com>,
Daniel Vetter <daniel@ffwll.ch>, Christoph Hellwig <hch@lst.de>,
Leon Romanovsky <leonro@nvidia.com>,
Max Gurtovoy <mgurtovoy@nvidia.com>,
Tarun Gupta <targupta@nvidia.com>
Subject: [PATCH v2 02/13] vfio/mdev: Allow the mdev_parent_ops to specify the device driver to bind
Date: Mon, 26 Apr 2021 17:00:04 -0300 [thread overview]
Message-ID: <2-v2-7667f42c9bad+935-vfio3_jgg@nvidia.com> (raw)
In-Reply-To: <0-v2-7667f42c9bad+935-vfio3_jgg@nvidia.com>
This allows a mdev driver to opt out of using vfio_mdev.c, instead the
driver will provide a 'struct mdev_driver' and register directly with the
driver core.
Much of mdev_parent_ops becomes unused in this mode:
- create()/remove() are done via the mdev_driver probe()/remove()
- mdev_attr_groups becomes mdev_driver driver.dev_groups
- Wrapper function callbacks are replaced with the same ones from
struct vfio_device_ops
Following patches convert all the drivers.
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
drivers/vfio/mdev/mdev_core.c | 64 ++++++++++++++++++++++++++++-----
drivers/vfio/mdev/mdev_driver.c | 17 ++++++++-
include/linux/mdev.h | 3 ++
3 files changed, 75 insertions(+), 9 deletions(-)
diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
index ff8c1a84516698..51b8a9fcf866ad 100644
--- a/drivers/vfio/mdev/mdev_core.c
+++ b/drivers/vfio/mdev/mdev_core.c
@@ -94,9 +94,11 @@ static void mdev_device_remove_common(struct mdev_device *mdev)
mdev_remove_sysfs_files(mdev);
device_del(&mdev->dev);
lockdep_assert_held(&parent->unreg_sem);
- ret = parent->ops->remove(mdev);
- if (ret)
- dev_err(&mdev->dev, "Remove failed: err=%d\n", ret);
+ if (parent->ops->remove) {
+ ret = parent->ops->remove(mdev);
+ if (ret)
+ dev_err(&mdev->dev, "Remove failed: err=%d\n", ret);
+ }
/* Balances with device_initialize() */
put_device(&mdev->dev);
@@ -127,7 +129,9 @@ 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->create || !ops->remove || !ops->supported_type_groups)
+ if (!ops || !ops->supported_type_groups)
+ return -EINVAL;
+ if (!ops->device_driver && (!ops->create || !ops->remove))
return -EINVAL;
dev = get_device(dev);
@@ -251,6 +255,43 @@ static void mdev_device_release(struct device *dev)
kfree(mdev);
}
+/*
+ * mdev drivers can refuse to bind during probe(), in this case we want to fail
+ * the creation of the mdev all the way back to sysfs. This is a weird model
+ * that doesn't fit in the driver core well, nor does it seem to appear any
+ * place else in the kernel, so use a simple hack.
+ */
+static int mdev_bind_driver(struct mdev_device *mdev)
+{
+ struct mdev_driver *drv = mdev->type->parent->ops->device_driver;
+ int ret;
+
+ if (!drv)
+ drv = &vfio_mdev_driver;
+
+ while (1) {
+ device_lock(&mdev->dev);
+ if (mdev->dev.driver == &drv->driver) {
+ ret = 0;
+ goto out_unlock;
+ }
+ if (mdev->probe_err) {
+ ret = mdev->probe_err;
+ goto out_unlock;
+ }
+ device_unlock(&mdev->dev);
+ ret = device_attach(&mdev->dev);
+ if (ret)
+ return ret;
+ mdev->probe_err = -EINVAL;
+ }
+ return 0;
+
+out_unlock:
+ device_unlock(&mdev->dev);
+ return ret;
+}
+
int mdev_device_create(struct mdev_type *type, const guid_t *uuid)
{
int ret;
@@ -296,14 +337,20 @@ int mdev_device_create(struct mdev_type *type, const guid_t *uuid)
goto out_put_device;
}
- ret = parent->ops->create(mdev);
- if (ret)
- goto out_unlock;
+ if (parent->ops->create) {
+ ret = parent->ops->create(mdev);
+ if (ret)
+ goto out_unlock;
+ }
ret = device_add(&mdev->dev);
if (ret)
goto out_remove;
+ ret = mdev_bind_driver(mdev);
+ if (ret)
+ goto out_del;
+
ret = mdev_create_sysfs_files(mdev);
if (ret)
goto out_del;
@@ -317,7 +364,8 @@ int mdev_device_create(struct mdev_type *type, const guid_t *uuid)
out_del:
device_del(&mdev->dev);
out_remove:
- parent->ops->remove(mdev);
+ if (parent->ops->remove)
+ parent->ops->remove(mdev);
out_unlock:
up_read(&parent->unreg_sem);
out_put_device:
diff --git a/drivers/vfio/mdev/mdev_driver.c b/drivers/vfio/mdev/mdev_driver.c
index 041699571b7e55..6e96c023d7823d 100644
--- a/drivers/vfio/mdev/mdev_driver.c
+++ b/drivers/vfio/mdev/mdev_driver.c
@@ -49,7 +49,7 @@ static int mdev_probe(struct device *dev)
return ret;
if (drv->probe) {
- ret = drv->probe(mdev);
+ ret = mdev->probe_err = drv->probe(mdev);
if (ret)
mdev_detach_iommu(mdev);
}
@@ -71,10 +71,25 @@ static int mdev_remove(struct device *dev)
return 0;
}
+static int mdev_match(struct device *dev, struct device_driver *drv)
+{
+ struct mdev_device *mdev = to_mdev_device(dev);
+ struct mdev_driver *target = mdev->type->parent->ops->device_driver;
+
+ /*
+ * The ops specify the device driver to connect, fall back to the old
+ * shim driver if the driver hasn't been converted.
+ */
+ if (!target)
+ target = &vfio_mdev_driver;
+ return drv == &target->driver;
+}
+
struct bus_type mdev_bus_type = {
.name = "mdev",
.probe = mdev_probe,
.remove = mdev_remove,
+ .match = mdev_match,
};
EXPORT_SYMBOL_GPL(mdev_bus_type);
diff --git a/include/linux/mdev.h b/include/linux/mdev.h
index 1fb34ea394ad46..49cc4f65120d57 100644
--- a/include/linux/mdev.h
+++ b/include/linux/mdev.h
@@ -19,6 +19,7 @@ struct mdev_device {
struct list_head next;
struct mdev_type *type;
struct device *iommu_device;
+ int probe_err;
bool active;
};
@@ -55,6 +56,7 @@ struct device *mtype_get_parent_dev(struct mdev_type *mtype);
* register the device to mdev module.
*
* @owner: The module owner.
+ * @device_driver: Which device driver to probe() on newly created devices
* @dev_attr_groups: Attributes of the parent device.
* @mdev_attr_groups: Attributes of the mediated device.
* @supported_type_groups: Attributes to define supported types. It is mandatory
@@ -103,6 +105,7 @@ struct device *mtype_get_parent_dev(struct mdev_type *mtype);
**/
struct mdev_parent_ops {
struct module *owner;
+ struct mdev_driver *device_driver;
const struct attribute_group **dev_attr_groups;
const struct attribute_group **mdev_attr_groups;
struct attribute_group **supported_type_groups;
--
2.31.1
next prev parent reply other threads:[~2021-04-26 20:00 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-26 20:00 [PATCH v2 00/13] Remove vfio_mdev.c, mdev_parent_ops and more Jason Gunthorpe
2021-04-26 20:00 ` [PATCH v2 01/13] vfio/mdev: Remove CONFIG_VFIO_MDEV_DEVICE Jason Gunthorpe
2021-04-27 11:05 ` Cornelia Huck
2021-04-26 20:00 ` Jason Gunthorpe [this message]
2021-04-27 12:32 ` [PATCH v2 02/13] vfio/mdev: Allow the mdev_parent_ops to specify the device driver to bind Cornelia Huck
2021-04-27 23:20 ` Jason Gunthorpe
2021-04-28 6:03 ` Christoph Hellwig
2021-04-28 7:56 ` Dan Williams
2021-04-28 12:41 ` Christoph Hellwig
2021-04-28 14:00 ` Jason Gunthorpe
2021-04-28 19:58 ` Dan Williams
2021-04-28 23:38 ` Jason Gunthorpe
2021-04-29 0:00 ` Dave Jiang
2021-05-26 0:42 ` Jason Gunthorpe
2021-05-26 1:42 ` Dan Williams
2021-05-27 11:44 ` Christoph Hellwig
2021-05-27 14:53 ` Jason Gunthorpe
2021-05-27 15:13 ` Christoph Hellwig
2021-04-29 6:51 ` Christoph Hellwig
2021-05-04 9:36 ` Christoph Hellwig
2021-05-04 11:30 ` Jason Gunthorpe
2021-04-28 6:44 ` Leon Romanovsky
2021-04-28 14:14 ` Jason Gunthorpe
2021-04-28 14:24 ` Leon Romanovsky
2021-04-26 20:00 ` [PATCH v2 03/13] vfio/mtty: Convert to use vfio_register_group_dev() Jason Gunthorpe
2021-04-26 20:00 ` [PATCH v2 04/13] vfio/mdpy: " Jason Gunthorpe
2021-04-26 20:00 ` [PATCH v2 05/13] vfio/mbochs: " Jason Gunthorpe
2021-04-26 20:00 ` [PATCH v2 07/13] vfio/ccw: " Jason Gunthorpe
2021-04-27 20:06 ` Eric Farman
2021-04-27 22:10 ` Jason Gunthorpe
2021-04-28 12:55 ` Eric Farman
2021-04-28 13:21 ` Jason Gunthorpe
2021-04-28 17:09 ` Cornelia Huck
2021-04-28 17:20 ` Jason Gunthorpe
2021-04-29 11:58 ` Cornelia Huck
2021-04-29 18:13 ` Jason Gunthorpe
2021-04-30 12:31 ` Cornelia Huck
2021-04-30 17:19 ` Jason Gunthorpe
2021-05-03 10:54 ` s390 common I/O layer locking (was: [PATCH v2 07/13] vfio/ccw: Convert to use vfio_register_group_dev()) Cornelia Huck
2021-05-04 15:10 ` s390 common I/O layer locking Vineeth Vijayan
2021-07-24 13:24 ` Christoph Hellwig
2021-08-03 14:27 ` Vineeth Vijayan
2021-08-10 15:00 ` Cornelia Huck
2021-04-26 20:00 ` [PATCH v2 09/13] vfio/mdev: Remove vfio_mdev.c Jason Gunthorpe
2021-04-28 6:07 ` Christoph Hellwig
2021-04-28 6:36 ` Greg Kroah-Hartman
2021-04-28 12:53 ` Jason Gunthorpe
2021-04-29 6:53 ` Christoph Hellwig
2021-04-29 6:56 ` Greg Kroah-Hartman
2021-05-03 17:32 ` Jason Gunthorpe
2021-05-04 9:38 ` Christoph Hellwig
2021-05-04 16:20 ` Jason Gunthorpe
2021-04-26 20:00 ` [PATCH v2 10/13] vfio/mdev: Remove mdev_parent_ops dev_attr_groups Jason Gunthorpe
2021-04-26 20:00 ` [PATCH v2 11/13] vfio/mdev: Remove mdev_parent_ops Jason Gunthorpe
2021-04-26 20:00 ` [PATCH v2 12/13] vfio/mdev: Use the driver core to create the 'remove' file Jason Gunthorpe
2021-04-26 20:00 ` [PATCH v2 13/13] vfio/mdev: Remove mdev drvdata Jason Gunthorpe
2021-04-27 21:30 ` [PATCH v2 00/13] Remove vfio_mdev.c, mdev_parent_ops and more Alex Williamson
2021-04-27 22:20 ` Jason Gunthorpe
2021-04-27 22:49 ` Alex Williamson
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