[PATCH v2 00/15] Tidy up vfio_device life cycle

[PATCH v2 00/15] Tidy up vfio_device life cycle

[Kevin Tian]

The idea is to let vfio core manage the vfio_device life cycle instead
of duplicating the logic cross drivers. Besides cleaner code in driver
side this also allows adding struct device to vfio_device as the first
step toward adding cdev uAPI in the future. Another benefit is that
user can now look at sysfs to decide whether a device is bound to
vfio [1], e.g.:

	/sys/devices/pci0000\:6f/0000\:6f\:01.0/vfio-dev/vfio0

Though most drivers can fit the new model naturally:

 - vfio_alloc_device() to allocate and initialize vfio_device
 - vfio_put_device() to release vfio_device
 - dev_ops->init() for driver private initialization
 - dev_ops->release() for driver private cleanup

vfio-ccw is the only exception due to a life cycle mess that its private
structure mixes both parent and mdev info hence must be alloc/freed
outside of the life cycle of vfio device.

Per prior discussions this won't be fixed in short term by IBM folks [2].

Instead of waiting this series introduces a few tricks to move forward:

 - vfio_init_device() to initialize a pre-allocated device structure;

 - require *EVERY* driver to implement @release and free vfio_device
   inside. Then vfio-ccw can use a completion mechanism to delay the
   free to css driver;

The second trick is not a real burden to other drivers because they
all require a @release for private cleanup anyay. Later once the ccw
mess is fixed a simple cleanup can be done by moving free from @release
to vfio core.

v2:
 - rebase to 6.0-rc3
 - fix build warnings (lkp)
 - patch1: remove unnecessary forward reference (Jason)
 - patch10: leave device_set released by vfio core (Jason)
 - patch13: add Suggested-by
 - patch15: add ABI file sysfs-devices-vfio-dev (Alex)
 - patch15: rename 'vfio' to 'vfio_group' in procfs (Jason)
v1: https://lore.kernel.org/lkml/20220827171037.30297-1-kevin.tian@intel.com/

--
@Alex, before knowing your merging preference this is only rebased to
6.0-rc3.

There is no conflict with:

 - Remove private items from linux/vfio_pci_core.h
 - Break up ioctl dispatch functions to one function per ioctl

But conflict exists with Jason's two series:

 - Allow MMIO regions to be exported through dma-buf
 - vfio: Split the container code into a clean layer and dedicated file

Thanks
Kevin

[1] https://listman.redhat.com/archives/libvir-list/2022-August/233482.html
[2] https://lore.kernel.org/all/0ee29bd6583f17f0ee4ec0769fa50e8ea6703623.camel@linux.ibm.com/

Kevin Tian (6):
  vfio: Add helpers for unifying vfio_device life cycle
  drm/i915/gvt: Use the new device life cycle helpers
  vfio/platform: Use the new device life cycle helpers
  vfio/amba: Use the new device life cycle helpers
  vfio/ccw: Use the new device life cycle helpers
  vfio: Rename vfio_device_put() and vfio_device_try_get()

Yi Liu (9):
  vfio/pci: Use the new device life cycle helpers
  vfio/mlx5: Use the new device life cycle helpers
  vfio/hisi_acc: Use the new device life cycle helpers
  vfio/mdpy: Use the new device life cycle helpers
  vfio/mtty: Use the new device life cycle helpers
  vfio/mbochs: Use the new device life cycle helpers
  vfio/ap: Use the new device life cycle helpers
  vfio/fsl-mc: Use the new device life cycle helpers
  vfio: Add struct device to vfio_device

 .../ABI/testing/sysfs-devices-vfio-dev        |   8 +
 drivers/gpu/drm/i915/gvt/gvt.h                |   5 +-
 drivers/gpu/drm/i915/gvt/kvmgt.c              |  52 ++++--
 drivers/gpu/drm/i915/gvt/vgpu.c               |  33 ++--
 drivers/s390/cio/vfio_ccw_ops.c               |  52 +++++-
 drivers/s390/cio/vfio_ccw_private.h           |   3 +
 drivers/s390/crypto/vfio_ap_ops.c             |  50 +++---
 drivers/vfio/fsl-mc/vfio_fsl_mc.c             |  85 +++++----
 .../vfio/pci/hisilicon/hisi_acc_vfio_pci.c    |  80 ++++-----
 drivers/vfio/pci/mlx5/main.c                  |  49 +++--
 drivers/vfio/pci/vfio_pci.c                   |  20 +--
 drivers/vfio/pci/vfio_pci_core.c              |  23 ++-
 drivers/vfio/platform/vfio_amba.c             |  72 ++++++--
 drivers/vfio/platform/vfio_platform.c         |  66 +++++--
 drivers/vfio/platform/vfio_platform_common.c  |  71 +++-----
 drivers/vfio/platform/vfio_platform_private.h |  18 +-
 drivers/vfio/vfio_main.c                      | 167 +++++++++++++++---
 include/linux/vfio.h                          |  28 ++-
 include/linux/vfio_pci_core.h                 |   6 +-
 samples/vfio-mdev/mbochs.c                    |  73 +++++---
 samples/vfio-mdev/mdpy.c                      |  81 +++++----
 samples/vfio-mdev/mtty.c                      |  67 ++++---
 22 files changed, 729 insertions(+), 380 deletions(-)
 create mode 100644 Documentation/ABI/testing/sysfs-devices-vfio-dev


base-commit: b90cb1053190353cc30f0fef0ef1f378ccc063c5
-- 
2.21.3

[PATCH v2 01/15] vfio: Add helpers for unifying vfio_device life cycle

[Kevin Tian]

The idea is to let vfio core manage the vfio_device life cycle instead
of duplicating the logic cross drivers. This is also a preparatory
step for adding struct device into vfio_device.

New pair of helpers together with a kref in vfio_device:

 - vfio_alloc_device()
 - vfio_put_device()

Drivers can register @init/@release callbacks to manage any priviate
state wrapping the vfio_device.

However vfio-ccw doesn't fit this model due to a life cycle mess
that its private structure mixes both parent and mdev info hence must
be allocated/freed outside of the life cycle of vfio device.

Per prior discussions this won't be fixed in short term by IBM folks.

Instead of waiting introduce another helper vfio_init_device() so ccw
can call it to initialize a pre-allocated vfio_device.

Further implication of the ccw trick is that vfio_device cannot be
freed uniformly in vfio core. Instead, require *EVERY* driver to
implement @release and free vfio_device inside. Then ccw can choose
to delay the free at its own discretion.

Another trick down the road is that kvzalloc() is used to accommodate
the need of gvt which uses vzalloc() while all others use kzalloc().
So drivers should call a helper vfio_free_device() to free the
vfio_device instead of assuming that kfree() or vfree() is appliable.

Later once the ccw mess is fixed we can remove those tricks and
fully handle structure alloc/free in vfio core.

Existing vfio_{un}init_group_dev() will be deprecated after all
existing usages are converted to the new model.

Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Co-developed-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
---
 drivers/vfio/vfio_main.c | 92 ++++++++++++++++++++++++++++++++++++++++
 include/linux/vfio.h     | 25 ++++++++++-
 2 files changed, 116 insertions(+), 1 deletion(-)

diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
index 7cb56c382c97..c9d982131265 100644
--- a/drivers/vfio/vfio_main.c
+++ b/drivers/vfio/vfio_main.c
@@ -496,6 +496,98 @@ void vfio_uninit_group_dev(struct vfio_device *device)
 }
 EXPORT_SYMBOL_GPL(vfio_uninit_group_dev);
 
+/* Release helper called by vfio_put_device() */
+void vfio_device_release(struct kref *kref)
+{
+	struct vfio_device *device =
+			container_of(kref, struct vfio_device, kref);
+
+	vfio_uninit_group_dev(device);
+
+	/*
+	 * kvfree() cannot be done here due to a life cycle mess in
+	 * vfio-ccw. Before the ccw part is fixed all drivers are
+	 * required to support @release and call vfio_free_device()
+	 * from there.
+	 */
+	device->ops->release(device);
+}
+EXPORT_SYMBOL_GPL(vfio_device_release);
+
+/*
+ * Alloc and initialize vfio_device so it can be registered to vfio
+ * core.
+ *
+ * Drivers should use the wrapper vfio_alloc_device() for allocation.
+ * @size is the size of the structure to be allocated, including any
+ * private data used by the driver.
+ *
+ * Driver may provide an @init callback to cover device private data.
+ *
+ * Use vfio_put_device() to release the structure after success return.
+ */
+struct vfio_device *_vfio_alloc_device(size_t size, struct device *dev,
+				       const struct vfio_device_ops *ops)
+{
+	struct vfio_device *device;
+	int ret;
+
+	if (WARN_ON(size < sizeof(struct vfio_device)))
+		return ERR_PTR(-EINVAL);
+
+	device = kvzalloc(size, GFP_KERNEL);
+	if (!device)
+		return ERR_PTR(-ENOMEM);
+
+	ret = vfio_init_device(device, dev, ops);
+	if (ret)
+		goto out_free;
+	return device;
+
+out_free:
+	kvfree(device);
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(_vfio_alloc_device);
+
+/*
+ * Initialize a vfio_device so it can be registered to vfio core.
+ *
+ * Only vfio-ccw driver should call this interface.
+ */
+int vfio_init_device(struct vfio_device *device, struct device *dev,
+		     const struct vfio_device_ops *ops)
+{
+	int ret;
+
+	vfio_init_group_dev(device, dev, ops);
+
+	if (ops->init) {
+		ret = ops->init(device);
+		if (ret)
+			goto out_uninit;
+	}
+
+	kref_init(&device->kref);
+	return 0;
+
+out_uninit:
+	vfio_uninit_group_dev(device);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(vfio_init_device);
+
+/*
+ * The helper called by driver @release callback to free the device
+ * structure. Drivers which don't have private data to clean can
+ * simply use this helper as its @release.
+ */
+void vfio_free_device(struct vfio_device *device)
+{
+	kvfree(device);
+}
+EXPORT_SYMBOL_GPL(vfio_free_device);
+
 static struct vfio_group *vfio_noiommu_group_alloc(struct device *dev,
 		enum vfio_group_type type)
 {
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index e05ddc6fe6a5..e1e9e8352903 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -45,7 +45,8 @@ struct vfio_device {
 	struct kvm *kvm;
 
 	/* Members below here are private, not for driver use */
-	refcount_t refcount;
+	struct kref kref;	/* object life cycle */
+	refcount_t refcount;	/* user count on registered device*/
 	unsigned int open_count;
 	struct completion comp;
 	struct list_head group_next;
@@ -55,6 +56,8 @@ struct vfio_device {
 /**
  * struct vfio_device_ops - VFIO bus driver device callbacks
  *
+ * @init: initialize private fields in device structure
+ * @release: Reclaim private fields in device structure
  * @open_device: Called when the first file descriptor is opened for this device
  * @close_device: Opposite of open_device
  * @read: Perform read(2) on device file descriptor
@@ -72,6 +75,8 @@ struct vfio_device {
  */
 struct vfio_device_ops {
 	char	*name;
+	int	(*init)(struct vfio_device *vdev);
+	void	(*release)(struct vfio_device *vdev);
 	int	(*open_device)(struct vfio_device *vdev);
 	void	(*close_device)(struct vfio_device *vdev);
 	ssize_t	(*read)(struct vfio_device *vdev, char __user *buf,
@@ -137,6 +142,24 @@ static inline int vfio_check_feature(u32 flags, size_t argsz, u32 supported_ops,
 	return 1;
 }
 
+struct vfio_device *_vfio_alloc_device(size_t size, struct device *dev,
+				       const struct vfio_device_ops *ops);
+#define vfio_alloc_device(dev_struct, member, dev, ops)				\
+	container_of(_vfio_alloc_device(sizeof(struct dev_struct) +		\
+					BUILD_BUG_ON_ZERO(offsetof(		\
+						struct dev_struct, member)),	\
+					dev, ops),				\
+		     struct dev_struct, member)
+
+int vfio_init_device(struct vfio_device *device, struct device *dev,
+		     const struct vfio_device_ops *ops);
+void vfio_free_device(struct vfio_device *device);
+void vfio_device_release(struct kref *kref);
+static inline void vfio_put_device(struct vfio_device *device)
+{
+	kref_put(&device->kref, vfio_device_release);
+}
+
 void vfio_init_group_dev(struct vfio_device *device, struct device *dev,
 			 const struct vfio_device_ops *ops);
 void vfio_uninit_group_dev(struct vfio_device *device);
-- 
2.21.3

Re: [PATCH v2 01/15] vfio: Add helpers for unifying vfio_device life cycle

[Christoph Hellwig]

What is the point?  This adds indirect calls, and actually creates
more boilerplate code in the drivers.  i.g. when using this code there
is more, and harder to read code.

RE: [PATCH v2 01/15] vfio: Add helpers for unifying vfio_device life cycle

[Tian, Kevin]

> From: Christoph Hellwig
> Sent: Tuesday, September 6, 2022 5:42 PM
> 
> What is the point?  This adds indirect calls, and actually creates
> more boilerplate code in the drivers.  i.g. when using this code there
> is more, and harder to read code.

The point is to align with struct device life cycle when it's introduced
to vfio_device. The object is released via put_device() then what would
be the alternative if the driver doesn't provide a @release callback?

and with @release then naturally @init is also expected.

Most added code is in patch1 for implementing new helpers and
patch15 for introducing struct device.

Remaining addition is relatively small when scattered in each driver
and most is due to creating new functions hence new local variables.

and IMHO the readability is improved as it clearly contains the
init/release logic around the device object.

Thanks
Kevin

Re: [PATCH v2 01/15] vfio: Add helpers for unifying vfio_device life cycle

[Christoph Hellwig]

On Wed, Sep 07, 2022 at 12:43:30AM +0000, Tian, Kevin wrote:
> > From: Christoph Hellwig
> > Sent: Tuesday, September 6, 2022 5:42 PM
> > 
> > What is the point?  This adds indirect calls, and actually creates
> > more boilerplate code in the drivers.  i.g. when using this code there
> > is more, and harder to read code.
> 
> The point is to align with struct device life cycle when it's introduced
> to vfio_device. The object is released via put_device() then what would
> be the alternative if the driver doesn't provide a @release callback?
> 
> and with @release then naturally @init is also expected.

No, with a release no @init is expected.  The init method is one
of the major obsfucations here, only topped by the weird
vfio_alloc_device macro.  Yes, that saves about 4 lines of code
in every driver, but places a burden on the struct layout and
very much obsfucated things.  Without vfio_alloc_device and
the init method I think much of this would make a lot more sense.

See the patch below that goes on top of this series to show how
undoing these two would look on mbochs.  It it a slight reduction
lines of code, but more readable and much less churn compared
to the status before this series.

diff --git a/samples/vfio-mdev/mbochs.c b/samples/vfio-mdev/mbochs.c
index df95f25fbc0ede..7f01b335fd4dbd 100644
--- a/samples/vfio-mdev/mbochs.c
+++ b/samples/vfio-mdev/mbochs.c
@@ -505,14 +505,12 @@ static int mbochs_reset(struct mdev_state *mdev_state)
 	return 0;
 }
 
-static int mbochs_init_dev(struct vfio_device *vdev)
+static int mbochs_probe(struct mdev_device *mdev)
 {
-	struct mdev_state *mdev_state =
-		container_of(vdev, struct mdev_state, vdev);
-	struct mdev_device *mdev = to_mdev_device(vdev->dev);
+	int avail_mbytes = atomic_read(&mbochs_avail_mbytes);
 	const struct mbochs_type *type =
 		&mbochs_types[mdev_get_type_group_id(mdev)];
-	int avail_mbytes = atomic_read(&mbochs_avail_mbytes);
+	struct mdev_state *mdev_state;
 	int ret = -ENOMEM;
 
 	do {
@@ -521,10 +519,14 @@ static int mbochs_init_dev(struct vfio_device *vdev)
 	} while (!atomic_try_cmpxchg(&mbochs_avail_mbytes, &avail_mbytes,
 				     avail_mbytes - type->mbytes));
 
-	mdev_state->vconfig = kzalloc(MBOCHS_CONFIG_SPACE_SIZE, GFP_KERNEL);
-	if (!mdev_state->vconfig)
+	mdev_state = kzalloc(sizeof(struct mdev_state), GFP_KERNEL);
+	if (mdev_state == NULL)
 		goto err_avail;
 
+	mdev_state->vconfig = kzalloc(MBOCHS_CONFIG_SPACE_SIZE, GFP_KERNEL);
+	if (mdev_state->vconfig == NULL)
+		goto err_state;
+
 	mdev_state->memsize = type->mbytes * 1024 * 1024;
 	mdev_state->pagecount = mdev_state->memsize >> PAGE_SHIFT;
 	mdev_state->pages = kcalloc(mdev_state->pagecount,
@@ -546,38 +548,33 @@ static int mbochs_init_dev(struct vfio_device *vdev)
 	mbochs_create_config_space(mdev_state);
 	mbochs_reset(mdev_state);
 
+	ret = vfio_init_device(&mdev_state->vdev, &mdev->dev, &mbochs_dev_ops);
+	if (ret)
+		goto err_mem;
+
+	ret = vfio_register_emulated_iommu_dev(&mdev_state->vdev);
+	if (ret) {
+		vfio_put_device(&mdev_state->vdev);
+		return ret;
+	}
+
 	dev_info(vdev->dev, "%s: %s, %d MB, %ld pages\n", __func__,
 		 type->name, type->mbytes, mdev_state->pagecount);
+
+	dev_set_drvdata(&mdev->dev, mdev_state);
 	return 0;
 
+err_mem:
+	kfree(mdev_state->pages);
 err_vconfig:
 	kfree(mdev_state->vconfig);
+err_state:
+	kfree(mdev_state);
 err_avail:
 	atomic_add(type->mbytes, &mbochs_avail_mbytes);
 	return ret;
 }
 
-static int mbochs_probe(struct mdev_device *mdev)
-{
-	struct mdev_state *mdev_state;
-	int ret = -ENOMEM;
-
-	mdev_state = vfio_alloc_device(mdev_state, vdev, &mdev->dev,
-				       &mbochs_dev_ops);
-	if (IS_ERR(mdev_state))
-		return PTR_ERR(mdev_state);
-
-	ret = vfio_register_emulated_iommu_dev(&mdev_state->vdev);
-	if (ret)
-		goto err_put_vdev;
-	dev_set_drvdata(&mdev->dev, mdev_state);
-	return 0;
-
-err_put_vdev:
-	vfio_put_device(&mdev_state->vdev);
-	return ret;
-}
-
 static void mbochs_release_dev(struct vfio_device *vdev)
 {
 	struct mdev_state *mdev_state =
@@ -585,7 +582,7 @@ static void mbochs_release_dev(struct vfio_device *vdev)
 
 	kfree(mdev_state->pages);
 	kfree(mdev_state->vconfig);
-	vfio_free_device(vdev);
+	kfree(vdev);
 	atomic_add(mdev_state->type->mbytes, &mbochs_avail_mbytes);
 }
 
@@ -1414,7 +1411,6 @@ static struct attribute_group *mdev_type_groups[] = {
 
 static const struct vfio_device_ops mbochs_dev_ops = {
 	.close_device = mbochs_close_device,
-	.init = mbochs_init_dev,
 	.release = mbochs_release_dev,
 	.read = mbochs_read,
 	.write = mbochs_write,

Re: [PATCH v2 01/15] vfio: Add helpers for unifying vfio_device life cycle

[Jason Gunthorpe]

On Wed, Sep 07, 2022 at 04:55:18AM -0700, Christoph Hellwig wrote:
> On Wed, Sep 07, 2022 at 12:43:30AM +0000, Tian, Kevin wrote:
> > > From: Christoph Hellwig
> > > Sent: Tuesday, September 6, 2022 5:42 PM
> > > 
> > > What is the point?  This adds indirect calls, and actually creates
> > > more boilerplate code in the drivers.  i.g. when using this code there
> > > is more, and harder to read code.
> > 
> > The point is to align with struct device life cycle when it's introduced
> > to vfio_device. The object is released via put_device() then what would
> > be the alternative if the driver doesn't provide a @release callback?
> > 
> > and with @release then naturally @init is also expected.
> 
> No, with a release no @init is expected.  The init method is one
> of the major obsfucations here, only topped by the weird
> vfio_alloc_device macro.  Yes, that saves about 4 lines of code
> in every driver, but places a burden on the struct layout and
> very much obsfucated things.  Without vfio_alloc_device and
> the init method I think much of this would make a lot more sense.
> 
> See the patch below that goes on top of this series to show how
> undoing these two would look on mbochs.  It it a slight reduction
> lines of code, but more readable and much less churn compared
> to the status before this series.

I've seen alot of error handling bugs caused by open-coding patterns
like this. People get confused about what the lifecycle is and botch
the error unwinds, almost 100% of the time :\ They call kfree when
they should call put_device, they call put_device before initing
enough stuff that the release callback doesn't crash, double free
stuff by calling put_device at the wrong point, and so on.

The advantage of init/release is the strict pairing and the core code
helping get the error unwind right, by not calling release until init
succeeds.

The advantage of the vfio_alloc_device() is not saving 4 lines, it is
giving the drivers a simple/sane error handling strategy. Goto unwind
inside init, release undoes everything init does and the probe path
only calls put_device(). It is simple and logical to implement and
hard to make subtle bugs.

Specifically it eliminates the open coded transition of kfree to
put_device that seems so difficult for people to get right.

netdev has done a version of this, so has rdma, and it works well.

Jason

Re: [PATCH v2 01/15] vfio: Add helpers for unifying vfio_device life cycle

[Eric Auger]

Hi Kevin,
On 9/1/22 16:37, Kevin Tian wrote:
> The idea is to let vfio core manage the vfio_device life cycle instead
> of duplicating the logic cross drivers. This is also a preparatory
> step for adding struct device into vfio_device.
>
> New pair of helpers together with a kref in vfio_device:
>
>  - vfio_alloc_device()
>  - vfio_put_device()
>
> Drivers can register @init/@release callbacks to manage any priviate
private
> state wrapping the vfio_device.
>
> However vfio-ccw doesn't fit this model due to a life cycle mess
> that its private structure mixes both parent and mdev info hence must
> be allocated/freed outside of the life cycle of vfio device.
>
> Per prior discussions this won't be fixed in short term by IBM folks.
>
> Instead of waiting introduce another helper vfio_init_device() so ccw
s/waiting/waiting for those modifications,
> can call it to initialize a pre-allocated vfio_device.
>
> Further implication of the ccw trick is that vfio_device cannot be
> freed uniformly in vfio core. Instead, require *EVERY* driver to
> implement @release and free vfio_device inside. Then ccw can choose
> to delay the free at its own discretion.
>
> Another trick down the road is that kvzalloc() is used to accommodate
> the need of gvt which uses vzalloc() while all others use kzalloc().
> So drivers should call a helper vfio_free_device() to free the
> vfio_device instead of assuming that kfree() or vfree() is appliable.
>
> Later once the ccw mess is fixed we can remove those tricks and
> fully handle structure alloc/free in vfio core.
>
> Existing vfio_{un}init_group_dev() will be deprecated after all
> existing usages are converted to the new model.
>
> Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
> Co-developed-by: Yi Liu <yi.l.liu@intel.com>
> Signed-off-by: Yi Liu <yi.l.liu@intel.com>
> Signed-off-by: Kevin Tian <kevin.tian@intel.com>
> Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
> ---
>  drivers/vfio/vfio_main.c | 92 ++++++++++++++++++++++++++++++++++++++++
>  include/linux/vfio.h     | 25 ++++++++++-
>  2 files changed, 116 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
> index 7cb56c382c97..c9d982131265 100644
> --- a/drivers/vfio/vfio_main.c
> +++ b/drivers/vfio/vfio_main.c
> @@ -496,6 +496,98 @@ void vfio_uninit_group_dev(struct vfio_device *device)
>  }
>  EXPORT_SYMBOL_GPL(vfio_uninit_group_dev);
>  
> +/* Release helper called by vfio_put_device() */
> +void vfio_device_release(struct kref *kref)
> +{
> +	struct vfio_device *device =
> +			container_of(kref, struct vfio_device, kref);
> +
> +	vfio_uninit_group_dev(device);
> +
> +	/*
> +	 * kvfree() cannot be done here due to a life cycle mess in
> +	 * vfio-ccw. Before the ccw part is fixed all drivers are
> +	 * required to support @release and call vfio_free_device()
> +	 * from there.
> +	 */
> +	device->ops->release(device);
> +}
> +EXPORT_SYMBOL_GPL(vfio_device_release);
> +
> +/*
> + * Alloc and initialize vfio_device so it can be registered to vfio
> + * core.
> + *
> + * Drivers should use the wrapper vfio_alloc_device() for allocation.
> + * @size is the size of the structure to be allocated, including any
> + * private data used by the driver.
> + *
> + * Driver may provide an @init callback to cover device private data.
nit: this comment may rather relate to the vfio_init_device function
> + *
> + * Use vfio_put_device() to release the structure after success return.
> + */
> +struct vfio_device *_vfio_alloc_device(size_t size, struct device *dev,
> +				       const struct vfio_device_ops *ops)
> +{
> +	struct vfio_device *device;
> +	int ret;
> +
> +	if (WARN_ON(size < sizeof(struct vfio_device)))
> +		return ERR_PTR(-EINVAL);
> +
> +	device = kvzalloc(size, GFP_KERNEL);
> +	if (!device)
> +		return ERR_PTR(-ENOMEM);
> +
> +	ret = vfio_init_device(device, dev, ops);
> +	if (ret)
> +		goto out_free;
> +	return device;
> +
> +out_free:
> +	kvfree(device);
> +	return ERR_PTR(ret);
> +}
> +EXPORT_SYMBOL_GPL(_vfio_alloc_device);
> +
> +/*
> + * Initialize a vfio_device so it can be registered to vfio core.
> + *
> + * Only vfio-ccw driver should call this interface.
> + */
> +int vfio_init_device(struct vfio_device *device, struct device *dev,
> +		     const struct vfio_device_ops *ops)
> +{
> +	int ret;
> +
> +	vfio_init_group_dev(device, dev, ops);
> +
> +	if (ops->init) {
> +		ret = ops->init(device);
> +		if (ret)
> +			goto out_uninit;
> +	}
> +
> +	kref_init(&device->kref);
> +	return 0;
> +
> +out_uninit:
> +	vfio_uninit_group_dev(device);
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(vfio_init_device);
> +
> +/*
> + * The helper called by driver @release callback to free the device
> + * structure. Drivers which don't have private data to clean can
> + * simply use this helper as its @release.
> + */
> +void vfio_free_device(struct vfio_device *device)
> +{
> +	kvfree(device);
> +}
> +EXPORT_SYMBOL_GPL(vfio_free_device);
> +
>  static struct vfio_group *vfio_noiommu_group_alloc(struct device *dev,
>  		enum vfio_group_type type)
>  {
> diff --git a/include/linux/vfio.h b/include/linux/vfio.h
> index e05ddc6fe6a5..e1e9e8352903 100644
> --- a/include/linux/vfio.h
> +++ b/include/linux/vfio.h
> @@ -45,7 +45,8 @@ struct vfio_device {
>  	struct kvm *kvm;
>  
>  	/* Members below here are private, not for driver use */
> -	refcount_t refcount;
> +	struct kref kref;	/* object life cycle */
> +	refcount_t refcount;	/* user count on registered device*/
>  	unsigned int open_count;
>  	struct completion comp;
>  	struct list_head group_next;
> @@ -55,6 +56,8 @@ struct vfio_device {
>  /**
>   * struct vfio_device_ops - VFIO bus driver device callbacks
>   *
> + * @init: initialize private fields in device structure
> + * @release: Reclaim private fields in device structure
>   * @open_device: Called when the first file descriptor is opened for this device
>   * @close_device: Opposite of open_device
>   * @read: Perform read(2) on device file descriptor
> @@ -72,6 +75,8 @@ struct vfio_device {
>   */
>  struct vfio_device_ops {
>  	char	*name;
> +	int	(*init)(struct vfio_device *vdev);
> +	void	(*release)(struct vfio_device *vdev);
>  	int	(*open_device)(struct vfio_device *vdev);
>  	void	(*close_device)(struct vfio_device *vdev);
>  	ssize_t	(*read)(struct vfio_device *vdev, char __user *buf,
> @@ -137,6 +142,24 @@ static inline int vfio_check_feature(u32 flags, size_t argsz, u32 supported_ops,
>  	return 1;
>  }
>  
> +struct vfio_device *_vfio_alloc_device(size_t size, struct device *dev,
> +				       const struct vfio_device_ops *ops);
> +#define vfio_alloc_device(dev_struct, member, dev, ops)				\
> +	container_of(_vfio_alloc_device(sizeof(struct dev_struct) +		\
> +					BUILD_BUG_ON_ZERO(offsetof(		\
> +						struct dev_struct, member)),	\
> +					dev, ops),				\
> +		     struct dev_struct, member)
> +
> +int vfio_init_device(struct vfio_device *device, struct device *dev,
> +		     const struct vfio_device_ops *ops);
> +void vfio_free_device(struct vfio_device *device);
> +void vfio_device_release(struct kref *kref);
> +static inline void vfio_put_device(struct vfio_device *device)
> +{
> +	kref_put(&device->kref, vfio_device_release);
> +}
> +
>  void vfio_init_group_dev(struct vfio_device *device, struct device *dev,
>  			 const struct vfio_device_ops *ops);
>  void vfio_uninit_group_dev(struct vfio_device *device);
Besides

Reviewed-by: Eric Auger <eric.auger@redhat.com>

Eric

RE: [PATCH v2 01/15] vfio: Add helpers for unifying vfio_device life cycle

[Tian, Kevin]

> From: Eric Auger <eric.auger@redhat.com>
> Sent: Thursday, September 8, 2022 3:28 AM
> > +/*
> > + * Alloc and initialize vfio_device so it can be registered to vfio
> > + * core.
> > + *
> > + * Drivers should use the wrapper vfio_alloc_device() for allocation.
> > + * @size is the size of the structure to be allocated, including any
> > + * private data used by the driver.
> > + *
> > + * Driver may provide an @init callback to cover device private data.
> nit: this comment may rather relate to the vfio_init_device function

Yes but vfio_init_device() is used only by ccw and presumably will be
abandoned once ccw fixes its life cycle mess. Given that I prefer to leaving
the comment here to be noted by broader users.

> Besides
> 
> Reviewed-by: Eric Auger <eric.auger@redhat.com>
> 

Thanks and other comments adopted. 

Re: [PATCH v2 01/15] vfio: Add helpers for unifying vfio_device life cycle

[Eric Auger]

Hi Kevin,

On 9/8/22 08:19, Tian, Kevin wrote:
>> From: Eric Auger <eric.auger@redhat.com>
>> Sent: Thursday, September 8, 2022 3:28 AM
>>> +/*
>>> + * Alloc and initialize vfio_device so it can be registered to vfio
>>> + * core.
>>> + *
>>> + * Drivers should use the wrapper vfio_alloc_device() for allocation.
>>> + * @size is the size of the structure to be allocated, including any
>>> + * private data used by the driver.
>>> + *
>>> + * Driver may provide an @init callback to cover device private data.
>> nit: this comment may rather relate to the vfio_init_device function
> Yes but vfio_init_device() is used only by ccw and presumably will be
> abandoned once ccw fixes its life cycle mess. Given that I prefer to leaving
> the comment here to be noted by broader users.

OK

Eric
>
>> Besides
>>
>> Reviewed-by: Eric Auger <eric.auger@redhat.com>
>>
> Thanks and other comments adopted. 

[PATCH v2 02/15] vfio/pci: Use the new device life cycle helpers

[Kevin Tian]

From: Yi Liu <yi.l.liu@intel.com>

Also introduce two pci core helpers as @init/@release for pci drivers:

 - vfio_pci_core_init_dev()
 - vfio_pci_core_release_dev()

Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
---
 drivers/vfio/pci/vfio_pci.c      | 20 +++++++++---------
 drivers/vfio/pci/vfio_pci_core.c | 35 ++++++++++++++++++++++++++++++++
 include/linux/vfio_pci_core.h    |  2 ++
 3 files changed, 47 insertions(+), 10 deletions(-)

diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index 4d1a97415a27..c1223c458615 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -127,6 +127,8 @@ static int vfio_pci_open_device(struct vfio_device *core_vdev)
 
 static const struct vfio_device_ops vfio_pci_ops = {
 	.name		= "vfio-pci",
+	.init		= vfio_pci_core_init_dev,
+	.release	= vfio_pci_core_release_dev,
 	.open_device	= vfio_pci_open_device,
 	.close_device	= vfio_pci_core_close_device,
 	.ioctl		= vfio_pci_core_ioctl,
@@ -146,20 +148,19 @@ static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	if (vfio_pci_is_denylisted(pdev))
 		return -EINVAL;
 
-	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
-	if (!vdev)
-		return -ENOMEM;
-	vfio_pci_core_init_device(vdev, pdev, &vfio_pci_ops);
+	vdev = vfio_alloc_device(vfio_pci_core_device, vdev, &pdev->dev,
+				 &vfio_pci_ops);
+	if (IS_ERR(vdev))
+		return PTR_ERR(vdev);
 
 	dev_set_drvdata(&pdev->dev, vdev);
 	ret = vfio_pci_core_register_device(vdev);
 	if (ret)
-		goto out_free;
+		goto out_put_vdev;
 	return 0;
 
-out_free:
-	vfio_pci_core_uninit_device(vdev);
-	kfree(vdev);
+out_put_vdev:
+	vfio_put_device(&vdev->vdev);
 	return ret;
 }
 
@@ -168,8 +169,7 @@ static void vfio_pci_remove(struct pci_dev *pdev)
 	struct vfio_pci_core_device *vdev = dev_get_drvdata(&pdev->dev);
 
 	vfio_pci_core_unregister_device(vdev);
-	vfio_pci_core_uninit_device(vdev);
-	kfree(vdev);
+	vfio_put_device(&vdev->vdev);
 }
 
 static int vfio_pci_sriov_configure(struct pci_dev *pdev, int nr_virtfn)
diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
index c8d3b0450fb3..708b61d1b364 100644
--- a/drivers/vfio/pci/vfio_pci_core.c
+++ b/drivers/vfio/pci/vfio_pci_core.c
@@ -1825,6 +1825,41 @@ static void vfio_pci_vga_uninit(struct vfio_pci_core_device *vdev)
 					      VGA_RSRC_LEGACY_MEM);
 }
 
+int vfio_pci_core_init_dev(struct vfio_device *core_vdev)
+{
+	struct vfio_pci_core_device *vdev =
+		container_of(core_vdev, struct vfio_pci_core_device, vdev);
+
+	vdev->pdev = to_pci_dev(core_vdev->dev);
+	vdev->irq_type = VFIO_PCI_NUM_IRQS;
+	mutex_init(&vdev->igate);
+	spin_lock_init(&vdev->irqlock);
+	mutex_init(&vdev->ioeventfds_lock);
+	INIT_LIST_HEAD(&vdev->dummy_resources_list);
+	INIT_LIST_HEAD(&vdev->ioeventfds_list);
+	mutex_init(&vdev->vma_lock);
+	INIT_LIST_HEAD(&vdev->vma_list);
+	INIT_LIST_HEAD(&vdev->sriov_pfs_item);
+	init_rwsem(&vdev->memory_lock);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(vfio_pci_core_init_dev);
+
+void vfio_pci_core_release_dev(struct vfio_device *core_vdev)
+{
+	struct vfio_pci_core_device *vdev =
+		container_of(core_vdev, struct vfio_pci_core_device, vdev);
+
+	mutex_destroy(&vdev->igate);
+	mutex_destroy(&vdev->ioeventfds_lock);
+	mutex_destroy(&vdev->vma_lock);
+	kfree(vdev->region);
+	kfree(vdev->pm_save);
+	vfio_free_device(core_vdev);
+}
+EXPORT_SYMBOL_GPL(vfio_pci_core_release_dev);
+
 void vfio_pci_core_init_device(struct vfio_pci_core_device *vdev,
 			       struct pci_dev *pdev,
 			       const struct vfio_device_ops *vfio_pci_ops)
diff --git a/include/linux/vfio_pci_core.h b/include/linux/vfio_pci_core.h
index 5579ece4347b..98c8c66e2400 100644
--- a/include/linux/vfio_pci_core.h
+++ b/include/linux/vfio_pci_core.h
@@ -233,6 +233,8 @@ void vfio_pci_core_close_device(struct vfio_device *core_vdev);
 void vfio_pci_core_init_device(struct vfio_pci_core_device *vdev,
 			       struct pci_dev *pdev,
 			       const struct vfio_device_ops *vfio_pci_ops);
+int vfio_pci_core_init_dev(struct vfio_device *core_vdev);
+void vfio_pci_core_release_dev(struct vfio_device *core_vdev);
 int vfio_pci_core_register_device(struct vfio_pci_core_device *vdev);
 void vfio_pci_core_uninit_device(struct vfio_pci_core_device *vdev);
 void vfio_pci_core_unregister_device(struct vfio_pci_core_device *vdev);
-- 
2.21.3

[PATCH v2 03/15] vfio/mlx5: Use the new device life cycle helpers

[Kevin Tian]

From: Yi Liu <yi.l.liu@intel.com>

mlx5 has its own @init/@release for handling migration cap.

Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
---
 drivers/vfio/pci/mlx5/main.c | 49 ++++++++++++++++++++++++++----------
 1 file changed, 36 insertions(+), 13 deletions(-)

diff --git a/drivers/vfio/pci/mlx5/main.c b/drivers/vfio/pci/mlx5/main.c
index a9b63d15c5d3..168c1133e337 100644
--- a/drivers/vfio/pci/mlx5/main.c
+++ b/drivers/vfio/pci/mlx5/main.c
@@ -579,8 +579,35 @@ static const struct vfio_migration_ops mlx5vf_pci_mig_ops = {
 	.migration_get_state = mlx5vf_pci_get_device_state,
 };
 
+static int mlx5vf_pci_init_dev(struct vfio_device *core_vdev)
+{
+	struct mlx5vf_pci_core_device *mvdev = container_of(core_vdev,
+			struct mlx5vf_pci_core_device, core_device.vdev);
+	int ret;
+
+	ret = vfio_pci_core_init_dev(core_vdev);
+	if (ret)
+		return ret;
+
+	mlx5vf_cmd_set_migratable(mvdev, &mlx5vf_pci_mig_ops);
+
+	return 0;
+
+}
+
+static void mlx5vf_pci_release_dev(struct vfio_device *core_vdev)
+{
+	struct mlx5vf_pci_core_device *mvdev = container_of(core_vdev,
+			struct mlx5vf_pci_core_device, core_device.vdev);
+
+	mlx5vf_cmd_remove_migratable(mvdev);
+	vfio_pci_core_release_dev(core_vdev);
+}
+
 static const struct vfio_device_ops mlx5vf_pci_ops = {
 	.name = "mlx5-vfio-pci",
+	.init = mlx5vf_pci_init_dev,
+	.release = mlx5vf_pci_release_dev,
 	.open_device = mlx5vf_pci_open_device,
 	.close_device = mlx5vf_pci_close_device,
 	.ioctl = vfio_pci_core_ioctl,
@@ -598,21 +625,19 @@ static int mlx5vf_pci_probe(struct pci_dev *pdev,
 	struct mlx5vf_pci_core_device *mvdev;
 	int ret;
 
-	mvdev = kzalloc(sizeof(*mvdev), GFP_KERNEL);
-	if (!mvdev)
-		return -ENOMEM;
-	vfio_pci_core_init_device(&mvdev->core_device, pdev, &mlx5vf_pci_ops);
-	mlx5vf_cmd_set_migratable(mvdev, &mlx5vf_pci_mig_ops);
+	mvdev = vfio_alloc_device(mlx5vf_pci_core_device, core_device.vdev,
+				  &pdev->dev, &mlx5vf_pci_ops);
+	if (IS_ERR(mvdev))
+		return PTR_ERR(mvdev);
+
 	dev_set_drvdata(&pdev->dev, &mvdev->core_device);
 	ret = vfio_pci_core_register_device(&mvdev->core_device);
 	if (ret)
-		goto out_free;
+		goto out_put_vdev;
 	return 0;
 
-out_free:
-	mlx5vf_cmd_remove_migratable(mvdev);
-	vfio_pci_core_uninit_device(&mvdev->core_device);
-	kfree(mvdev);
+out_put_vdev:
+	vfio_put_device(&mvdev->core_device.vdev);
 	return ret;
 }
 
@@ -621,9 +646,7 @@ static void mlx5vf_pci_remove(struct pci_dev *pdev)
 	struct mlx5vf_pci_core_device *mvdev = mlx5vf_drvdata(pdev);
 
 	vfio_pci_core_unregister_device(&mvdev->core_device);
-	mlx5vf_cmd_remove_migratable(mvdev);
-	vfio_pci_core_uninit_device(&mvdev->core_device);
-	kfree(mvdev);
+	vfio_put_device(&mvdev->core_device.vdev);
 }
 
 static const struct pci_device_id mlx5vf_pci_table[] = {
-- 
2.21.3

[PATCH v2 04/15] vfio/hisi_acc: Use the new device life cycle helpers

[Kevin Tian]

From: Yi Liu <yi.l.liu@intel.com>

Tidy up @probe so all migration specific initialization logic is moved
to migration specific @init callback.

Remove vfio_pci_core_{un}init_device() given no user now.

Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
---
 .../vfio/pci/hisilicon/hisi_acc_vfio_pci.c    | 80 +++++++++----------
 drivers/vfio/pci/vfio_pci_core.c              | 30 -------
 include/linux/vfio_pci_core.h                 |  4 -
 3 files changed, 37 insertions(+), 77 deletions(-)

diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
index ea762e28c1cc..f6e9c6b52eaa 100644
--- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
+++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
@@ -1213,8 +1213,28 @@ static const struct vfio_migration_ops hisi_acc_vfio_pci_migrn_state_ops = {
 	.migration_get_state = hisi_acc_vfio_pci_get_device_state,
 };
 
+static int hisi_acc_vfio_pci_migrn_init_dev(struct vfio_device *core_vdev)
+{
+	struct hisi_acc_vf_core_device *hisi_acc_vdev = container_of(core_vdev,
+			struct hisi_acc_vf_core_device, core_device.vdev);
+	struct pci_dev *pdev = to_pci_dev(core_vdev->dev);
+	struct hisi_qm *pf_qm = hisi_acc_get_pf_qm(pdev);
+
+	hisi_acc_vdev->vf_id = pci_iov_vf_id(pdev) + 1;
+	hisi_acc_vdev->pf_qm = pf_qm;
+	hisi_acc_vdev->vf_dev = pdev;
+	mutex_init(&hisi_acc_vdev->state_mutex);
+
+	core_vdev->migration_flags = VFIO_MIGRATION_STOP_COPY;
+	core_vdev->mig_ops = &hisi_acc_vfio_pci_migrn_state_ops;
+
+	return vfio_pci_core_init_dev(core_vdev);
+}
+
 static const struct vfio_device_ops hisi_acc_vfio_pci_migrn_ops = {
 	.name = "hisi-acc-vfio-pci-migration",
+	.init = hisi_acc_vfio_pci_migrn_init_dev,
+	.release = vfio_pci_core_release_dev,
 	.open_device = hisi_acc_vfio_pci_open_device,
 	.close_device = hisi_acc_vfio_pci_close_device,
 	.ioctl = hisi_acc_vfio_pci_ioctl,
@@ -1228,6 +1248,8 @@ static const struct vfio_device_ops hisi_acc_vfio_pci_migrn_ops = {
 
 static const struct vfio_device_ops hisi_acc_vfio_pci_ops = {
 	.name = "hisi-acc-vfio-pci",
+	.init = vfio_pci_core_init_dev,
+	.release = vfio_pci_core_release_dev,
 	.open_device = hisi_acc_vfio_pci_open_device,
 	.close_device = vfio_pci_core_close_device,
 	.ioctl = vfio_pci_core_ioctl,
@@ -1239,63 +1261,36 @@ static const struct vfio_device_ops hisi_acc_vfio_pci_ops = {
 	.match = vfio_pci_core_match,
 };
 
-static int
-hisi_acc_vfio_pci_migrn_init(struct hisi_acc_vf_core_device *hisi_acc_vdev,
-			     struct pci_dev *pdev, struct hisi_qm *pf_qm)
-{
-	int vf_id;
-
-	vf_id = pci_iov_vf_id(pdev);
-	if (vf_id < 0)
-		return vf_id;
-
-	hisi_acc_vdev->vf_id = vf_id + 1;
-	hisi_acc_vdev->core_device.vdev.migration_flags =
-					VFIO_MIGRATION_STOP_COPY;
-	hisi_acc_vdev->pf_qm = pf_qm;
-	hisi_acc_vdev->vf_dev = pdev;
-	mutex_init(&hisi_acc_vdev->state_mutex);
-
-	return 0;
-}
-
 static int hisi_acc_vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
 	struct hisi_acc_vf_core_device *hisi_acc_vdev;
+	const struct vfio_device_ops *ops = &hisi_acc_vfio_pci_ops;
 	struct hisi_qm *pf_qm;
+	int vf_id;
 	int ret;
 
-	hisi_acc_vdev = kzalloc(sizeof(*hisi_acc_vdev), GFP_KERNEL);
-	if (!hisi_acc_vdev)
-		return -ENOMEM;
-
 	pf_qm = hisi_acc_get_pf_qm(pdev);
 	if (pf_qm && pf_qm->ver >= QM_HW_V3) {
-		ret = hisi_acc_vfio_pci_migrn_init(hisi_acc_vdev, pdev, pf_qm);
-		if (!ret) {
-			vfio_pci_core_init_device(&hisi_acc_vdev->core_device, pdev,
-						  &hisi_acc_vfio_pci_migrn_ops);
-			hisi_acc_vdev->core_device.vdev.mig_ops =
-					&hisi_acc_vfio_pci_migrn_state_ops;
-		} else {
+		vf_id = pci_iov_vf_id(pdev);
+		if (vf_id >= 0)
+			ops = &hisi_acc_vfio_pci_migrn_ops;
+		else
 			pci_warn(pdev, "migration support failed, continue with generic interface\n");
-			vfio_pci_core_init_device(&hisi_acc_vdev->core_device, pdev,
-						  &hisi_acc_vfio_pci_ops);
-		}
-	} else {
-		vfio_pci_core_init_device(&hisi_acc_vdev->core_device, pdev,
-					  &hisi_acc_vfio_pci_ops);
 	}
 
+	hisi_acc_vdev = vfio_alloc_device(hisi_acc_vf_core_device,
+					  core_device.vdev, &pdev->dev, ops);
+	if (IS_ERR(hisi_acc_vdev))
+		return PTR_ERR(hisi_acc_vdev);
+
 	dev_set_drvdata(&pdev->dev, &hisi_acc_vdev->core_device);
 	ret = vfio_pci_core_register_device(&hisi_acc_vdev->core_device);
 	if (ret)
-		goto out_free;
+		goto out_put_vdev;
 	return 0;
 
-out_free:
-	vfio_pci_core_uninit_device(&hisi_acc_vdev->core_device);
-	kfree(hisi_acc_vdev);
+out_put_vdev:
+	vfio_put_device(&hisi_acc_vdev->core_device.vdev);
 	return ret;
 }
 
@@ -1304,8 +1299,7 @@ static void hisi_acc_vfio_pci_remove(struct pci_dev *pdev)
 	struct hisi_acc_vf_core_device *hisi_acc_vdev = hssi_acc_drvdata(pdev);
 
 	vfio_pci_core_unregister_device(&hisi_acc_vdev->core_device);
-	vfio_pci_core_uninit_device(&hisi_acc_vdev->core_device);
-	kfree(hisi_acc_vdev);
+	vfio_put_device(&hisi_acc_vdev->core_device.vdev);
 }
 
 static const struct pci_device_id hisi_acc_vfio_pci_table[] = {
diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
index 708b61d1b364..f29d780e327e 100644
--- a/drivers/vfio/pci/vfio_pci_core.c
+++ b/drivers/vfio/pci/vfio_pci_core.c
@@ -1860,36 +1860,6 @@ void vfio_pci_core_release_dev(struct vfio_device *core_vdev)
 }
 EXPORT_SYMBOL_GPL(vfio_pci_core_release_dev);
 
-void vfio_pci_core_init_device(struct vfio_pci_core_device *vdev,
-			       struct pci_dev *pdev,
-			       const struct vfio_device_ops *vfio_pci_ops)
-{
-	vfio_init_group_dev(&vdev->vdev, &pdev->dev, vfio_pci_ops);
-	vdev->pdev = pdev;
-	vdev->irq_type = VFIO_PCI_NUM_IRQS;
-	mutex_init(&vdev->igate);
-	spin_lock_init(&vdev->irqlock);
-	mutex_init(&vdev->ioeventfds_lock);
-	INIT_LIST_HEAD(&vdev->dummy_resources_list);
-	INIT_LIST_HEAD(&vdev->ioeventfds_list);
-	mutex_init(&vdev->vma_lock);
-	INIT_LIST_HEAD(&vdev->vma_list);
-	INIT_LIST_HEAD(&vdev->sriov_pfs_item);
-	init_rwsem(&vdev->memory_lock);
-}
-EXPORT_SYMBOL_GPL(vfio_pci_core_init_device);
-
-void vfio_pci_core_uninit_device(struct vfio_pci_core_device *vdev)
-{
-	mutex_destroy(&vdev->igate);
-	mutex_destroy(&vdev->ioeventfds_lock);
-	mutex_destroy(&vdev->vma_lock);
-	vfio_uninit_group_dev(&vdev->vdev);
-	kfree(vdev->region);
-	kfree(vdev->pm_save);
-}
-EXPORT_SYMBOL_GPL(vfio_pci_core_uninit_device);
-
 int vfio_pci_core_register_device(struct vfio_pci_core_device *vdev)
 {
 	struct pci_dev *pdev = vdev->pdev;
diff --git a/include/linux/vfio_pci_core.h b/include/linux/vfio_pci_core.h
index 98c8c66e2400..9f10ff34b2ba 100644
--- a/include/linux/vfio_pci_core.h
+++ b/include/linux/vfio_pci_core.h
@@ -230,13 +230,9 @@ static inline void vfio_pci_zdev_close_device(struct vfio_pci_core_device *vdev)
 void vfio_pci_core_set_params(bool nointxmask, bool is_disable_vga,
 			      bool is_disable_idle_d3);
 void vfio_pci_core_close_device(struct vfio_device *core_vdev);
-void vfio_pci_core_init_device(struct vfio_pci_core_device *vdev,
-			       struct pci_dev *pdev,
-			       const struct vfio_device_ops *vfio_pci_ops);
 int vfio_pci_core_init_dev(struct vfio_device *core_vdev);
 void vfio_pci_core_release_dev(struct vfio_device *core_vdev);
 int vfio_pci_core_register_device(struct vfio_pci_core_device *vdev);
-void vfio_pci_core_uninit_device(struct vfio_pci_core_device *vdev);
 void vfio_pci_core_unregister_device(struct vfio_pci_core_device *vdev);
 extern const struct pci_error_handlers vfio_pci_core_err_handlers;
 int vfio_pci_core_sriov_configure(struct vfio_pci_core_device *vdev,
-- 
2.21.3

[PATCH v2 05/15] vfio/mdpy: Use the new device life cycle helpers

[Kevin Tian]

From: Yi Liu <yi.l.liu@intel.com>

and manage mdpy_count inside @init/@release.

Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
---
 samples/vfio-mdev/mdpy.c | 81 +++++++++++++++++++++++-----------------
 1 file changed, 47 insertions(+), 34 deletions(-)

diff --git a/samples/vfio-mdev/mdpy.c b/samples/vfio-mdev/mdpy.c
index e8c46eb2e246..a07dac16d873 100644
--- a/samples/vfio-mdev/mdpy.c
+++ b/samples/vfio-mdev/mdpy.c
@@ -216,61 +216,77 @@ static int mdpy_reset(struct mdev_state *mdev_state)
 	return 0;
 }
 
-static int mdpy_probe(struct mdev_device *mdev)
+static int mdpy_init_dev(struct vfio_device *vdev)
 {
+	struct mdev_state *mdev_state =
+		container_of(vdev, struct mdev_state, vdev);
+	struct mdev_device *mdev = to_mdev_device(vdev->dev);
 	const struct mdpy_type *type =
 		&mdpy_types[mdev_get_type_group_id(mdev)];
-	struct device *dev = mdev_dev(mdev);
-	struct mdev_state *mdev_state;
 	u32 fbsize;
-	int ret;
+	int ret = -ENOMEM;
 
 	if (mdpy_count >= max_devices)
-		return -ENOMEM;
-
-	mdev_state = kzalloc(sizeof(struct mdev_state), GFP_KERNEL);
-	if (mdev_state == NULL)
-		return -ENOMEM;
-	vfio_init_group_dev(&mdev_state->vdev, &mdev->dev, &mdpy_dev_ops);
+		return ret;
 
 	mdev_state->vconfig = kzalloc(MDPY_CONFIG_SPACE_SIZE, GFP_KERNEL);
-	if (mdev_state->vconfig == NULL) {
-		ret = -ENOMEM;
-		goto err_state;
-	}
+	if (!mdev_state->vconfig)
+		return ret;
 
 	fbsize = roundup_pow_of_two(type->width * type->height * type->bytepp);
 
 	mdev_state->memblk = vmalloc_user(fbsize);
-	if (!mdev_state->memblk) {
-		ret = -ENOMEM;
-		goto err_vconfig;
-	}
-	dev_info(dev, "%s: %s (%dx%d)\n", __func__, type->name, type->width,
-		 type->height);
+	if (!mdev_state->memblk)
+		goto out_vconfig;
 
 	mutex_init(&mdev_state->ops_lock);
 	mdev_state->mdev = mdev;
-	mdev_state->type    = type;
+	mdev_state->type = type;
 	mdev_state->memsize = fbsize;
 	mdpy_create_config_space(mdev_state);
 	mdpy_reset(mdev_state);
 
+	dev_info(vdev->dev, "%s: %s (%dx%d)\n", __func__, type->name, type->width,
+		 type->height);
+
 	mdpy_count++;
+	return 0;
+
+out_vconfig:
+	kfree(mdev_state->vconfig);
+	return ret;
+}
+
+static int mdpy_probe(struct mdev_device *mdev)
+{
+	struct mdev_state *mdev_state;
+	int ret;
+
+	mdev_state = vfio_alloc_device(mdev_state, vdev, &mdev->dev,
+				       &mdpy_dev_ops);
+	if (IS_ERR(mdev_state))
+		return PTR_ERR(mdev_state);
 
 	ret = vfio_register_emulated_iommu_dev(&mdev_state->vdev);
 	if (ret)
-		goto err_mem;
+		goto err_put_vdev;
 	dev_set_drvdata(&mdev->dev, mdev_state);
 	return 0;
-err_mem:
+
+err_put_vdev:
+	vfio_put_device(&mdev_state->vdev);
+	return ret;
+}
+
+static void mdpy_release_dev(struct vfio_device *vdev)
+{
+	struct mdev_state *mdev_state =
+		container_of(vdev, struct mdev_state, vdev);
+
 	vfree(mdev_state->memblk);
-err_vconfig:
 	kfree(mdev_state->vconfig);
-err_state:
-	vfio_uninit_group_dev(&mdev_state->vdev);
-	kfree(mdev_state);
-	return ret;
+	vfio_free_device(vdev);
+	mdpy_count--;
 }
 
 static void mdpy_remove(struct mdev_device *mdev)
@@ -280,12 +296,7 @@ static void mdpy_remove(struct mdev_device *mdev)
 	dev_info(&mdev->dev, "%s\n", __func__);
 
 	vfio_unregister_group_dev(&mdev_state->vdev);
-	vfree(mdev_state->memblk);
-	kfree(mdev_state->vconfig);
-	vfio_uninit_group_dev(&mdev_state->vdev);
-	kfree(mdev_state);
-
-	mdpy_count--;
+	vfio_put_device(&mdev_state->vdev);
 }
 
 static ssize_t mdpy_read(struct vfio_device *vdev, char __user *buf,
@@ -708,6 +719,8 @@ static struct attribute_group *mdev_type_groups[] = {
 };
 
 static const struct vfio_device_ops mdpy_dev_ops = {
+	.init = mdpy_init_dev,
+	.release = mdpy_release_dev,
 	.read = mdpy_read,
 	.write = mdpy_write,
 	.ioctl = mdpy_ioctl,
-- 
2.21.3

[PATCH v2 06/15] vfio/mtty: Use the new device life cycle helpers

[Kevin Tian]

From: Yi Liu <yi.l.liu@intel.com>

and manage available ports inside @init/@release.

Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
---
 samples/vfio-mdev/mtty.c | 67 +++++++++++++++++++++++-----------------
 1 file changed, 39 insertions(+), 28 deletions(-)

diff --git a/samples/vfio-mdev/mtty.c b/samples/vfio-mdev/mtty.c
index f42a59ed2e3f..41301d50b247 100644
--- a/samples/vfio-mdev/mtty.c
+++ b/samples/vfio-mdev/mtty.c
@@ -703,9 +703,11 @@ static ssize_t mdev_access(struct mdev_state *mdev_state, u8 *buf, size_t count,
 	return ret;
 }
 
-static int mtty_probe(struct mdev_device *mdev)
+static int mtty_init_dev(struct vfio_device *vdev)
 {
-	struct mdev_state *mdev_state;
+	struct mdev_state *mdev_state =
+		container_of(vdev, struct mdev_state, vdev);
+	struct mdev_device *mdev = to_mdev_device(vdev->dev);
 	int nr_ports = mdev_get_type_group_id(mdev) + 1;
 	int avail_ports = atomic_read(&mdev_avail_ports);
 	int ret;
@@ -716,58 +718,65 @@ static int mtty_probe(struct mdev_device *mdev)
 	} while (!atomic_try_cmpxchg(&mdev_avail_ports,
 				     &avail_ports, avail_ports - nr_ports));
 
-	mdev_state = kzalloc(sizeof(struct mdev_state), GFP_KERNEL);
-	if (mdev_state == NULL) {
-		ret = -ENOMEM;
-		goto err_nr_ports;
-	}
-
-	vfio_init_group_dev(&mdev_state->vdev, &mdev->dev, &mtty_dev_ops);
-
 	mdev_state->nr_ports = nr_ports;
 	mdev_state->irq_index = -1;
 	mdev_state->s[0].max_fifo_size = MAX_FIFO_SIZE;
 	mdev_state->s[1].max_fifo_size = MAX_FIFO_SIZE;
 	mutex_init(&mdev_state->rxtx_lock);
-	mdev_state->vconfig = kzalloc(MTTY_CONFIG_SPACE_SIZE, GFP_KERNEL);
 
-	if (mdev_state->vconfig == NULL) {
+	mdev_state->vconfig = kzalloc(MTTY_CONFIG_SPACE_SIZE, GFP_KERNEL);
+	if (!mdev_state->vconfig) {
 		ret = -ENOMEM;
-		goto err_state;
+		goto err_nr_ports;
 	}
 
 	mutex_init(&mdev_state->ops_lock);
 	mdev_state->mdev = mdev;
-
 	mtty_create_config_space(mdev_state);
+	return 0;
+
+err_nr_ports:
+	atomic_add(nr_ports, &mdev_avail_ports);
+	return ret;
+}
+
+static int mtty_probe(struct mdev_device *mdev)
+{
+	struct mdev_state *mdev_state;
+	int ret;
+
+	mdev_state = vfio_alloc_device(mdev_state, vdev, &mdev->dev,
+				       &mtty_dev_ops);
+	if (IS_ERR(mdev_state))
+		return PTR_ERR(mdev_state);
 
 	ret = vfio_register_emulated_iommu_dev(&mdev_state->vdev);
 	if (ret)
-		goto err_vconfig;
+		goto err_put_vdev;
 	dev_set_drvdata(&mdev->dev, mdev_state);
 	return 0;
 
-err_vconfig:
-	kfree(mdev_state->vconfig);
-err_state:
-	vfio_uninit_group_dev(&mdev_state->vdev);
-	kfree(mdev_state);
-err_nr_ports:
-	atomic_add(nr_ports, &mdev_avail_ports);
+err_put_vdev:
+	vfio_put_device(&mdev_state->vdev);
 	return ret;
 }
 
+static void mtty_release_dev(struct vfio_device *vdev)
+{
+	struct mdev_state *mdev_state =
+		container_of(vdev, struct mdev_state, vdev);
+
+	kfree(mdev_state->vconfig);
+	vfio_free_device(vdev);
+	atomic_add(mdev_state->nr_ports, &mdev_avail_ports);
+}
+
 static void mtty_remove(struct mdev_device *mdev)
 {
 	struct mdev_state *mdev_state = dev_get_drvdata(&mdev->dev);
-	int nr_ports = mdev_state->nr_ports;
 
 	vfio_unregister_group_dev(&mdev_state->vdev);
-
-	kfree(mdev_state->vconfig);
-	vfio_uninit_group_dev(&mdev_state->vdev);
-	kfree(mdev_state);
-	atomic_add(nr_ports, &mdev_avail_ports);
+	vfio_put_device(&mdev_state->vdev);
 }
 
 static int mtty_reset(struct mdev_state *mdev_state)
@@ -1287,6 +1296,8 @@ static struct attribute_group *mdev_type_groups[] = {
 
 static const struct vfio_device_ops mtty_dev_ops = {
 	.name = "vfio-mtty",
+	.init = mtty_init_dev,
+	.release = mtty_release_dev,
 	.read = mtty_read,
 	.write = mtty_write,
 	.ioctl = mtty_ioctl,
-- 
2.21.3

[PATCH v2 07/15] vfio/mbochs: Use the new device life cycle helpers

[Kevin Tian]

From: Yi Liu <yi.l.liu@intel.com>

and manage avail_mbytes inside @init/@release.

Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
---
 samples/vfio-mdev/mbochs.c | 73 ++++++++++++++++++++++++--------------
 1 file changed, 46 insertions(+), 27 deletions(-)

diff --git a/samples/vfio-mdev/mbochs.c b/samples/vfio-mdev/mbochs.c
index 344c2901a82b..df95f25fbc0e 100644
--- a/samples/vfio-mdev/mbochs.c
+++ b/samples/vfio-mdev/mbochs.c
@@ -505,13 +505,14 @@ static int mbochs_reset(struct mdev_state *mdev_state)
 	return 0;
 }
 
-static int mbochs_probe(struct mdev_device *mdev)
+static int mbochs_init_dev(struct vfio_device *vdev)
 {
-	int avail_mbytes = atomic_read(&mbochs_avail_mbytes);
+	struct mdev_state *mdev_state =
+		container_of(vdev, struct mdev_state, vdev);
+	struct mdev_device *mdev = to_mdev_device(vdev->dev);
 	const struct mbochs_type *type =
 		&mbochs_types[mdev_get_type_group_id(mdev)];
-	struct device *dev = mdev_dev(mdev);
-	struct mdev_state *mdev_state;
+	int avail_mbytes = atomic_read(&mbochs_avail_mbytes);
 	int ret = -ENOMEM;
 
 	do {
@@ -520,14 +521,9 @@ static int mbochs_probe(struct mdev_device *mdev)
 	} while (!atomic_try_cmpxchg(&mbochs_avail_mbytes, &avail_mbytes,
 				     avail_mbytes - type->mbytes));
 
-	mdev_state = kzalloc(sizeof(struct mdev_state), GFP_KERNEL);
-	if (mdev_state == NULL)
-		goto err_avail;
-	vfio_init_group_dev(&mdev_state->vdev, &mdev->dev, &mbochs_dev_ops);
-
 	mdev_state->vconfig = kzalloc(MBOCHS_CONFIG_SPACE_SIZE, GFP_KERNEL);
-	if (mdev_state->vconfig == NULL)
-		goto err_mem;
+	if (!mdev_state->vconfig)
+		goto err_avail;
 
 	mdev_state->memsize = type->mbytes * 1024 * 1024;
 	mdev_state->pagecount = mdev_state->memsize >> PAGE_SHIFT;
@@ -535,10 +531,7 @@ static int mbochs_probe(struct mdev_device *mdev)
 				    sizeof(struct page *),
 				    GFP_KERNEL);
 	if (!mdev_state->pages)
-		goto err_mem;
-
-	dev_info(dev, "%s: %s, %d MB, %ld pages\n", __func__,
-		 type->name, type->mbytes, mdev_state->pagecount);
+		goto err_vconfig;
 
 	mutex_init(&mdev_state->ops_lock);
 	mdev_state->mdev = mdev;
@@ -553,19 +546,47 @@ static int mbochs_probe(struct mdev_device *mdev)
 	mbochs_create_config_space(mdev_state);
 	mbochs_reset(mdev_state);
 
+	dev_info(vdev->dev, "%s: %s, %d MB, %ld pages\n", __func__,
+		 type->name, type->mbytes, mdev_state->pagecount);
+	return 0;
+
+err_vconfig:
+	kfree(mdev_state->vconfig);
+err_avail:
+	atomic_add(type->mbytes, &mbochs_avail_mbytes);
+	return ret;
+}
+
+static int mbochs_probe(struct mdev_device *mdev)
+{
+	struct mdev_state *mdev_state;
+	int ret = -ENOMEM;
+
+	mdev_state = vfio_alloc_device(mdev_state, vdev, &mdev->dev,
+				       &mbochs_dev_ops);
+	if (IS_ERR(mdev_state))
+		return PTR_ERR(mdev_state);
+
 	ret = vfio_register_emulated_iommu_dev(&mdev_state->vdev);
 	if (ret)
-		goto err_mem;
+		goto err_put_vdev;
 	dev_set_drvdata(&mdev->dev, mdev_state);
 	return 0;
-err_mem:
-	vfio_uninit_group_dev(&mdev_state->vdev);
+
+err_put_vdev:
+	vfio_put_device(&mdev_state->vdev);
+	return ret;
+}
+
+static void mbochs_release_dev(struct vfio_device *vdev)
+{
+	struct mdev_state *mdev_state =
+		container_of(vdev, struct mdev_state, vdev);
+
 	kfree(mdev_state->pages);
 	kfree(mdev_state->vconfig);
-	kfree(mdev_state);
-err_avail:
-	atomic_add(type->mbytes, &mbochs_avail_mbytes);
-	return ret;
+	vfio_free_device(vdev);
+	atomic_add(mdev_state->type->mbytes, &mbochs_avail_mbytes);
 }
 
 static void mbochs_remove(struct mdev_device *mdev)
@@ -573,11 +594,7 @@ static void mbochs_remove(struct mdev_device *mdev)
 	struct mdev_state *mdev_state = dev_get_drvdata(&mdev->dev);
 
 	vfio_unregister_group_dev(&mdev_state->vdev);
-	vfio_uninit_group_dev(&mdev_state->vdev);
-	atomic_add(mdev_state->type->mbytes, &mbochs_avail_mbytes);
-	kfree(mdev_state->pages);
-	kfree(mdev_state->vconfig);
-	kfree(mdev_state);
+	vfio_put_device(&mdev_state->vdev);
 }
 
 static ssize_t mbochs_read(struct vfio_device *vdev, char __user *buf,
@@ -1397,6 +1414,8 @@ static struct attribute_group *mdev_type_groups[] = {
 
 static const struct vfio_device_ops mbochs_dev_ops = {
 	.close_device = mbochs_close_device,
+	.init = mbochs_init_dev,
+	.release = mbochs_release_dev,
 	.read = mbochs_read,
 	.write = mbochs_write,
 	.ioctl = mbochs_ioctl,
-- 
2.21.3

[PATCH v2 08/15] drm/i915/gvt: Use the new device life cycle helpers

[Kevin Tian]

Move vfio_device to the start of intel_vgpu as required by the new
helpers.

Change intel_gvt_create_vgpu() to use intel_vgpu as the first param
as other vgpu helpers do.

Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
---
 drivers/gpu/drm/i915/gvt/gvt.h   |  5 ++-
 drivers/gpu/drm/i915/gvt/kvmgt.c | 52 ++++++++++++++++++++++----------
 drivers/gpu/drm/i915/gvt/vgpu.c  | 33 ++++++++------------
 3 files changed, 50 insertions(+), 40 deletions(-)

diff --git a/drivers/gpu/drm/i915/gvt/gvt.h b/drivers/gpu/drm/i915/gvt/gvt.h
index 705689e64011..89fab7896fc6 100644
--- a/drivers/gpu/drm/i915/gvt/gvt.h
+++ b/drivers/gpu/drm/i915/gvt/gvt.h
@@ -172,6 +172,7 @@ struct intel_vgpu_submission {
 #define KVMGT_DEBUGFS_FILENAME		"kvmgt_nr_cache_entries"
 
 struct intel_vgpu {
+	struct vfio_device vfio_device;
 	struct intel_gvt *gvt;
 	struct mutex vgpu_lock;
 	int id;
@@ -211,7 +212,6 @@ struct intel_vgpu {
 
 	u32 scan_nonprivbb;
 
-	struct vfio_device vfio_device;
 	struct vfio_region *region;
 	int num_regions;
 	struct eventfd_ctx *intx_trigger;
@@ -494,8 +494,7 @@ void intel_gvt_clean_vgpu_types(struct intel_gvt *gvt);
 
 struct intel_vgpu *intel_gvt_create_idle_vgpu(struct intel_gvt *gvt);
 void intel_gvt_destroy_idle_vgpu(struct intel_vgpu *vgpu);
-struct intel_vgpu *intel_gvt_create_vgpu(struct intel_gvt *gvt,
-					 struct intel_vgpu_type *type);
+int intel_gvt_create_vgpu(struct intel_vgpu *vgpu, struct intel_vgpu_type *type);
 void intel_gvt_destroy_vgpu(struct intel_vgpu *vgpu);
 void intel_gvt_release_vgpu(struct intel_vgpu *vgpu);
 void intel_gvt_reset_vgpu_locked(struct intel_vgpu *vgpu, bool dmlr,
diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
index e3cd58946477..41bba40feef8 100644
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -1546,7 +1546,33 @@ static const struct attribute_group *intel_vgpu_groups[] = {
 	NULL,
 };
 
+static int intel_vgpu_init_dev(struct vfio_device *vfio_dev)
+{
+	struct mdev_device *mdev = to_mdev_device(vfio_dev->dev);
+	struct device *pdev = mdev_parent_dev(mdev);
+	struct intel_gvt *gvt = kdev_to_i915(pdev)->gvt;
+	struct intel_vgpu_type *type;
+	struct intel_vgpu *vgpu = vfio_dev_to_vgpu(vfio_dev);
+
+	type = &gvt->types[mdev_get_type_group_id(mdev)];
+	if (!type)
+		return -EINVAL;
+
+	vgpu->gvt = gvt;
+	return intel_gvt_create_vgpu(vgpu, type);
+}
+
+static void intel_vgpu_release_dev(struct vfio_device *vfio_dev)
+{
+	struct intel_vgpu *vgpu = vfio_dev_to_vgpu(vfio_dev);
+
+	intel_gvt_destroy_vgpu(vgpu);
+	vfio_free_device(vfio_dev);
+}
+
 static const struct vfio_device_ops intel_vgpu_dev_ops = {
+	.init		= intel_vgpu_init_dev,
+	.release	= intel_vgpu_release_dev,
 	.open_device	= intel_vgpu_open_device,
 	.close_device	= intel_vgpu_close_device,
 	.read		= intel_vgpu_read,
@@ -1558,35 +1584,28 @@ static const struct vfio_device_ops intel_vgpu_dev_ops = {
 
 static int intel_vgpu_probe(struct mdev_device *mdev)
 {
-	struct device *pdev = mdev_parent_dev(mdev);
-	struct intel_gvt *gvt = kdev_to_i915(pdev)->gvt;
-	struct intel_vgpu_type *type;
 	struct intel_vgpu *vgpu;
 	int ret;
 
-	type = &gvt->types[mdev_get_type_group_id(mdev)];
-	if (!type)
-		return -EINVAL;
-
-	vgpu = intel_gvt_create_vgpu(gvt, type);
+	vgpu = vfio_alloc_device(intel_vgpu, vfio_device, &mdev->dev,
+				 &intel_vgpu_dev_ops);
 	if (IS_ERR(vgpu)) {
 		gvt_err("failed to create intel vgpu: %ld\n", PTR_ERR(vgpu));
 		return PTR_ERR(vgpu);
 	}
 
-	vfio_init_group_dev(&vgpu->vfio_device, &mdev->dev,
-			    &intel_vgpu_dev_ops);
-
 	dev_set_drvdata(&mdev->dev, vgpu);
 	ret = vfio_register_emulated_iommu_dev(&vgpu->vfio_device);
-	if (ret) {
-		intel_gvt_destroy_vgpu(vgpu);
-		return ret;
-	}
+	if (ret)
+		goto out_put_vdev;
 
 	gvt_dbg_core("intel_vgpu_create succeeded for mdev: %s\n",
 		     dev_name(mdev_dev(mdev)));
 	return 0;
+
+out_put_vdev:
+	vfio_put_device(&vgpu->vfio_device);
+	return ret;
 }
 
 static void intel_vgpu_remove(struct mdev_device *mdev)
@@ -1595,7 +1614,8 @@ static void intel_vgpu_remove(struct mdev_device *mdev)
 
 	if (WARN_ON_ONCE(vgpu->attached))
 		return;
-	intel_gvt_destroy_vgpu(vgpu);
+
+	vfio_put_device(&vgpu->vfio_device);
 }
 
 static struct mdev_driver intel_vgpu_mdev_driver = {
diff --git a/drivers/gpu/drm/i915/gvt/vgpu.c b/drivers/gpu/drm/i915/gvt/vgpu.c
index 46da19b3225d..5c533fbc2c8d 100644
--- a/drivers/gpu/drm/i915/gvt/vgpu.c
+++ b/drivers/gpu/drm/i915/gvt/vgpu.c
@@ -302,8 +302,6 @@ void intel_gvt_destroy_vgpu(struct intel_vgpu *vgpu)
 	mutex_lock(&gvt->lock);
 	intel_gvt_update_vgpu_types(gvt);
 	mutex_unlock(&gvt->lock);
-
-	vfree(vgpu);
 }
 
 #define IDLE_VGPU_IDR 0
@@ -363,28 +361,23 @@ void intel_gvt_destroy_idle_vgpu(struct intel_vgpu *vgpu)
 	vfree(vgpu);
 }
 
-static struct intel_vgpu *__intel_gvt_create_vgpu(struct intel_gvt *gvt,
-		struct intel_vgpu_creation_params *param)
+static int __intel_gvt_create_vgpu(struct intel_vgpu *vgpu,
+				   struct intel_vgpu_creation_params *param)
 {
+	struct intel_gvt *gvt = vgpu->gvt;
 	struct drm_i915_private *dev_priv = gvt->gt->i915;
-	struct intel_vgpu *vgpu;
 	int ret;
 
 	gvt_dbg_core("low %llu MB high %llu MB fence %llu\n",
 			param->low_gm_sz, param->high_gm_sz,
 			param->fence_sz);
 
-	vgpu = vzalloc(sizeof(*vgpu));
-	if (!vgpu)
-		return ERR_PTR(-ENOMEM);
-
 	ret = idr_alloc(&gvt->vgpu_idr, vgpu, IDLE_VGPU_IDR + 1, GVT_MAX_VGPU,
 		GFP_KERNEL);
 	if (ret < 0)
-		goto out_free_vgpu;
+		return ret;
 
 	vgpu->id = ret;
-	vgpu->gvt = gvt;
 	vgpu->sched_ctl.weight = param->weight;
 	mutex_init(&vgpu->vgpu_lock);
 	mutex_init(&vgpu->dmabuf_lock);
@@ -437,7 +430,7 @@ static struct intel_vgpu *__intel_gvt_create_vgpu(struct intel_gvt *gvt,
 	if (ret)
 		goto out_clean_sched_policy;
 
-	return vgpu;
+	return 0;
 
 out_clean_sched_policy:
 	intel_vgpu_clean_sched_policy(vgpu);
@@ -455,9 +448,7 @@ static struct intel_vgpu *__intel_gvt_create_vgpu(struct intel_gvt *gvt,
 	intel_vgpu_clean_mmio(vgpu);
 out_clean_idr:
 	idr_remove(&gvt->vgpu_idr, vgpu->id);
-out_free_vgpu:
-	vfree(vgpu);
-	return ERR_PTR(ret);
+	return ret;
 }
 
 /**
@@ -470,11 +461,11 @@ static struct intel_vgpu *__intel_gvt_create_vgpu(struct intel_gvt *gvt,
  * Returns:
  * pointer to intel_vgpu, error pointer if failed.
  */
-struct intel_vgpu *intel_gvt_create_vgpu(struct intel_gvt *gvt,
-				struct intel_vgpu_type *type)
+int intel_gvt_create_vgpu(struct intel_vgpu *vgpu, struct intel_vgpu_type *type)
 {
+	struct intel_gvt *gvt = vgpu->gvt;
 	struct intel_vgpu_creation_params param;
-	struct intel_vgpu *vgpu;
+	int ret;
 
 	param.primary = 1;
 	param.low_gm_sz = type->low_gm_size;
@@ -488,15 +479,15 @@ struct intel_vgpu *intel_gvt_create_vgpu(struct intel_gvt *gvt,
 	param.high_gm_sz = BYTES_TO_MB(param.high_gm_sz);
 
 	mutex_lock(&gvt->lock);
-	vgpu = __intel_gvt_create_vgpu(gvt, &param);
-	if (!IS_ERR(vgpu)) {
+	ret = __intel_gvt_create_vgpu(vgpu, &param);
+	if (!ret) {
 		/* calculate left instance change for types */
 		intel_gvt_update_vgpu_types(gvt);
 		intel_gvt_update_reg_whitelist(vgpu);
 	}
 	mutex_unlock(&gvt->lock);
 
-	return vgpu;
+	return ret;
 }
 
 /**
-- 
2.21.3

Re: [PATCH v2 08/15] drm/i915/gvt: Use the new device life cycle helpers

[Zhenyu Wang]

[-- Attachment #1: Type: text/plain, Size: 8038 bytes --]

On 2022.09.01 22:37:40 +0800, Kevin Tian wrote:
> Move vfio_device to the start of intel_vgpu as required by the new
> helpers.
> 
> Change intel_gvt_create_vgpu() to use intel_vgpu as the first param
> as other vgpu helpers do.
> 
> Signed-off-by: Kevin Tian <kevin.tian@intel.com>
> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
> ---

Looks good to me.

Reviewed-by: Zhenyu Wang <zhenyuw@linux.intel.com>

>  drivers/gpu/drm/i915/gvt/gvt.h   |  5 ++-
>  drivers/gpu/drm/i915/gvt/kvmgt.c | 52 ++++++++++++++++++++++----------
>  drivers/gpu/drm/i915/gvt/vgpu.c  | 33 ++++++++------------
>  3 files changed, 50 insertions(+), 40 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gvt/gvt.h b/drivers/gpu/drm/i915/gvt/gvt.h
> index 705689e64011..89fab7896fc6 100644
> --- a/drivers/gpu/drm/i915/gvt/gvt.h
> +++ b/drivers/gpu/drm/i915/gvt/gvt.h
> @@ -172,6 +172,7 @@ struct intel_vgpu_submission {
>  #define KVMGT_DEBUGFS_FILENAME		"kvmgt_nr_cache_entries"
>  
>  struct intel_vgpu {
> +	struct vfio_device vfio_device;
>  	struct intel_gvt *gvt;
>  	struct mutex vgpu_lock;
>  	int id;
> @@ -211,7 +212,6 @@ struct intel_vgpu {
>  
>  	u32 scan_nonprivbb;
>  
> -	struct vfio_device vfio_device;
>  	struct vfio_region *region;
>  	int num_regions;
>  	struct eventfd_ctx *intx_trigger;
> @@ -494,8 +494,7 @@ void intel_gvt_clean_vgpu_types(struct intel_gvt *gvt);
>  
>  struct intel_vgpu *intel_gvt_create_idle_vgpu(struct intel_gvt *gvt);
>  void intel_gvt_destroy_idle_vgpu(struct intel_vgpu *vgpu);
> -struct intel_vgpu *intel_gvt_create_vgpu(struct intel_gvt *gvt,
> -					 struct intel_vgpu_type *type);
> +int intel_gvt_create_vgpu(struct intel_vgpu *vgpu, struct intel_vgpu_type *type);
>  void intel_gvt_destroy_vgpu(struct intel_vgpu *vgpu);
>  void intel_gvt_release_vgpu(struct intel_vgpu *vgpu);
>  void intel_gvt_reset_vgpu_locked(struct intel_vgpu *vgpu, bool dmlr,
> diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
> index e3cd58946477..41bba40feef8 100644
> --- a/drivers/gpu/drm/i915/gvt/kvmgt.c
> +++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
> @@ -1546,7 +1546,33 @@ static const struct attribute_group *intel_vgpu_groups[] = {
>  	NULL,
>  };
>  
> +static int intel_vgpu_init_dev(struct vfio_device *vfio_dev)
> +{
> +	struct mdev_device *mdev = to_mdev_device(vfio_dev->dev);
> +	struct device *pdev = mdev_parent_dev(mdev);
> +	struct intel_gvt *gvt = kdev_to_i915(pdev)->gvt;
> +	struct intel_vgpu_type *type;
> +	struct intel_vgpu *vgpu = vfio_dev_to_vgpu(vfio_dev);
> +
> +	type = &gvt->types[mdev_get_type_group_id(mdev)];
> +	if (!type)
> +		return -EINVAL;
> +
> +	vgpu->gvt = gvt;
> +	return intel_gvt_create_vgpu(vgpu, type);
> +}
> +
> +static void intel_vgpu_release_dev(struct vfio_device *vfio_dev)
> +{
> +	struct intel_vgpu *vgpu = vfio_dev_to_vgpu(vfio_dev);
> +
> +	intel_gvt_destroy_vgpu(vgpu);
> +	vfio_free_device(vfio_dev);
> +}
> +
>  static const struct vfio_device_ops intel_vgpu_dev_ops = {
> +	.init		= intel_vgpu_init_dev,
> +	.release	= intel_vgpu_release_dev,
>  	.open_device	= intel_vgpu_open_device,
>  	.close_device	= intel_vgpu_close_device,
>  	.read		= intel_vgpu_read,
> @@ -1558,35 +1584,28 @@ static const struct vfio_device_ops intel_vgpu_dev_ops = {
>  
>  static int intel_vgpu_probe(struct mdev_device *mdev)
>  {
> -	struct device *pdev = mdev_parent_dev(mdev);
> -	struct intel_gvt *gvt = kdev_to_i915(pdev)->gvt;
> -	struct intel_vgpu_type *type;
>  	struct intel_vgpu *vgpu;
>  	int ret;
>  
> -	type = &gvt->types[mdev_get_type_group_id(mdev)];
> -	if (!type)
> -		return -EINVAL;
> -
> -	vgpu = intel_gvt_create_vgpu(gvt, type);
> +	vgpu = vfio_alloc_device(intel_vgpu, vfio_device, &mdev->dev,
> +				 &intel_vgpu_dev_ops);
>  	if (IS_ERR(vgpu)) {
>  		gvt_err("failed to create intel vgpu: %ld\n", PTR_ERR(vgpu));
>  		return PTR_ERR(vgpu);
>  	}
>  
> -	vfio_init_group_dev(&vgpu->vfio_device, &mdev->dev,
> -			    &intel_vgpu_dev_ops);
> -
>  	dev_set_drvdata(&mdev->dev, vgpu);
>  	ret = vfio_register_emulated_iommu_dev(&vgpu->vfio_device);
> -	if (ret) {
> -		intel_gvt_destroy_vgpu(vgpu);
> -		return ret;
> -	}
> +	if (ret)
> +		goto out_put_vdev;
>  
>  	gvt_dbg_core("intel_vgpu_create succeeded for mdev: %s\n",
>  		     dev_name(mdev_dev(mdev)));
>  	return 0;
> +
> +out_put_vdev:
> +	vfio_put_device(&vgpu->vfio_device);
> +	return ret;
>  }
>  
>  static void intel_vgpu_remove(struct mdev_device *mdev)
> @@ -1595,7 +1614,8 @@ static void intel_vgpu_remove(struct mdev_device *mdev)
>  
>  	if (WARN_ON_ONCE(vgpu->attached))
>  		return;
> -	intel_gvt_destroy_vgpu(vgpu);
> +
> +	vfio_put_device(&vgpu->vfio_device);
>  }
>  
>  static struct mdev_driver intel_vgpu_mdev_driver = {
> diff --git a/drivers/gpu/drm/i915/gvt/vgpu.c b/drivers/gpu/drm/i915/gvt/vgpu.c
> index 46da19b3225d..5c533fbc2c8d 100644
> --- a/drivers/gpu/drm/i915/gvt/vgpu.c
> +++ b/drivers/gpu/drm/i915/gvt/vgpu.c
> @@ -302,8 +302,6 @@ void intel_gvt_destroy_vgpu(struct intel_vgpu *vgpu)
>  	mutex_lock(&gvt->lock);
>  	intel_gvt_update_vgpu_types(gvt);
>  	mutex_unlock(&gvt->lock);
> -
> -	vfree(vgpu);
>  }
>  
>  #define IDLE_VGPU_IDR 0
> @@ -363,28 +361,23 @@ void intel_gvt_destroy_idle_vgpu(struct intel_vgpu *vgpu)
>  	vfree(vgpu);
>  }
>  
> -static struct intel_vgpu *__intel_gvt_create_vgpu(struct intel_gvt *gvt,
> -		struct intel_vgpu_creation_params *param)
> +static int __intel_gvt_create_vgpu(struct intel_vgpu *vgpu,
> +				   struct intel_vgpu_creation_params *param)
>  {
> +	struct intel_gvt *gvt = vgpu->gvt;
>  	struct drm_i915_private *dev_priv = gvt->gt->i915;
> -	struct intel_vgpu *vgpu;
>  	int ret;
>  
>  	gvt_dbg_core("low %llu MB high %llu MB fence %llu\n",
>  			param->low_gm_sz, param->high_gm_sz,
>  			param->fence_sz);
>  
> -	vgpu = vzalloc(sizeof(*vgpu));
> -	if (!vgpu)
> -		return ERR_PTR(-ENOMEM);
> -
>  	ret = idr_alloc(&gvt->vgpu_idr, vgpu, IDLE_VGPU_IDR + 1, GVT_MAX_VGPU,
>  		GFP_KERNEL);
>  	if (ret < 0)
> -		goto out_free_vgpu;
> +		return ret;
>  
>  	vgpu->id = ret;
> -	vgpu->gvt = gvt;
>  	vgpu->sched_ctl.weight = param->weight;
>  	mutex_init(&vgpu->vgpu_lock);
>  	mutex_init(&vgpu->dmabuf_lock);
> @@ -437,7 +430,7 @@ static struct intel_vgpu *__intel_gvt_create_vgpu(struct intel_gvt *gvt,
>  	if (ret)
>  		goto out_clean_sched_policy;
>  
> -	return vgpu;
> +	return 0;
>  
>  out_clean_sched_policy:
>  	intel_vgpu_clean_sched_policy(vgpu);
> @@ -455,9 +448,7 @@ static struct intel_vgpu *__intel_gvt_create_vgpu(struct intel_gvt *gvt,
>  	intel_vgpu_clean_mmio(vgpu);
>  out_clean_idr:
>  	idr_remove(&gvt->vgpu_idr, vgpu->id);
> -out_free_vgpu:
> -	vfree(vgpu);
> -	return ERR_PTR(ret);
> +	return ret;
>  }
>  
>  /**
> @@ -470,11 +461,11 @@ static struct intel_vgpu *__intel_gvt_create_vgpu(struct intel_gvt *gvt,
>   * Returns:
>   * pointer to intel_vgpu, error pointer if failed.
>   */
> -struct intel_vgpu *intel_gvt_create_vgpu(struct intel_gvt *gvt,
> -				struct intel_vgpu_type *type)
> +int intel_gvt_create_vgpu(struct intel_vgpu *vgpu, struct intel_vgpu_type *type)
>  {
> +	struct intel_gvt *gvt = vgpu->gvt;
>  	struct intel_vgpu_creation_params param;
> -	struct intel_vgpu *vgpu;
> +	int ret;
>  
>  	param.primary = 1;
>  	param.low_gm_sz = type->low_gm_size;
> @@ -488,15 +479,15 @@ struct intel_vgpu *intel_gvt_create_vgpu(struct intel_gvt *gvt,
>  	param.high_gm_sz = BYTES_TO_MB(param.high_gm_sz);
>  
>  	mutex_lock(&gvt->lock);
> -	vgpu = __intel_gvt_create_vgpu(gvt, &param);
> -	if (!IS_ERR(vgpu)) {
> +	ret = __intel_gvt_create_vgpu(vgpu, &param);
> +	if (!ret) {
>  		/* calculate left instance change for types */
>  		intel_gvt_update_vgpu_types(gvt);
>  		intel_gvt_update_reg_whitelist(vgpu);
>  	}
>  	mutex_unlock(&gvt->lock);
>  
> -	return vgpu;
> +	return ret;
>  }
>  
>  /**
> -- 
> 2.21.3
> 

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 195 bytes --]

[PATCH v2 09/15] vfio/ap: Use the new device life cycle helpers

[Kevin Tian]

From: Yi Liu <yi.l.liu@intel.com>

and manage available_instances inside @init/@release.

Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
---
 drivers/s390/crypto/vfio_ap_ops.c | 50 ++++++++++++++++++-------------
 1 file changed, 29 insertions(+), 21 deletions(-)

diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index 6c8c41fac4e1..803aadfd0876 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -684,42 +684,44 @@ static bool vfio_ap_mdev_filter_matrix(unsigned long *apm, unsigned long *aqm,
 			     AP_DOMAINS);
 }
 
-static int vfio_ap_mdev_probe(struct mdev_device *mdev)
+static int vfio_ap_mdev_init_dev(struct vfio_device *vdev)
 {
-	struct ap_matrix_mdev *matrix_mdev;
-	int ret;
+	struct ap_matrix_mdev *matrix_mdev =
+		container_of(vdev, struct ap_matrix_mdev, vdev);
 
 	if ((atomic_dec_if_positive(&matrix_dev->available_instances) < 0))
 		return -EPERM;
 
-	matrix_mdev = kzalloc(sizeof(*matrix_mdev), GFP_KERNEL);
-	if (!matrix_mdev) {
-		ret = -ENOMEM;
-		goto err_dec_available;
-	}
-	vfio_init_group_dev(&matrix_mdev->vdev, &mdev->dev,
-			    &vfio_ap_matrix_dev_ops);
-
-	matrix_mdev->mdev = mdev;
+	matrix_mdev->mdev = to_mdev_device(vdev->dev);
 	vfio_ap_matrix_init(&matrix_dev->info, &matrix_mdev->matrix);
 	matrix_mdev->pqap_hook = handle_pqap;
 	vfio_ap_matrix_init(&matrix_dev->info, &matrix_mdev->shadow_apcb);
 	hash_init(matrix_mdev->qtable.queues);
 
+	return 0;
+}
+
+static int vfio_ap_mdev_probe(struct mdev_device *mdev)
+{
+	struct ap_matrix_mdev *matrix_mdev;
+	int ret;
+
+	matrix_mdev = vfio_alloc_device(ap_matrix_mdev, vdev, &mdev->dev,
+					&vfio_ap_matrix_dev_ops);
+	if (IS_ERR(matrix_mdev))
+		return PTR_ERR(matrix_mdev);
+
 	ret = vfio_register_emulated_iommu_dev(&matrix_mdev->vdev);
 	if (ret)
-		goto err_list;
+		goto err_put_vdev;
 	dev_set_drvdata(&mdev->dev, matrix_mdev);
 	mutex_lock(&matrix_dev->mdevs_lock);
 	list_add(&matrix_mdev->node, &matrix_dev->mdev_list);
 	mutex_unlock(&matrix_dev->mdevs_lock);
 	return 0;
 
-err_list:
-	vfio_uninit_group_dev(&matrix_mdev->vdev);
-	kfree(matrix_mdev);
-err_dec_available:
-	atomic_inc(&matrix_dev->available_instances);
+err_put_vdev:
+	vfio_put_device(&matrix_mdev->vdev);
 	return ret;
 }
 
@@ -766,6 +768,12 @@ static void vfio_ap_mdev_unlink_fr_queues(struct ap_matrix_mdev *matrix_mdev)
 	}
 }
 
+static void vfio_ap_mdev_release_dev(struct vfio_device *vdev)
+{
+	vfio_free_device(vdev);
+	atomic_inc(&matrix_dev->available_instances);
+}
+
 static void vfio_ap_mdev_remove(struct mdev_device *mdev)
 {
 	struct ap_matrix_mdev *matrix_mdev = dev_get_drvdata(&mdev->dev);
@@ -779,9 +787,7 @@ static void vfio_ap_mdev_remove(struct mdev_device *mdev)
 	list_del(&matrix_mdev->node);
 	mutex_unlock(&matrix_dev->mdevs_lock);
 	mutex_unlock(&matrix_dev->guests_lock);
-	vfio_uninit_group_dev(&matrix_mdev->vdev);
-	kfree(matrix_mdev);
-	atomic_inc(&matrix_dev->available_instances);
+	vfio_put_device(&matrix_mdev->vdev);
 }
 
 static ssize_t name_show(struct mdev_type *mtype,
@@ -1794,6 +1800,8 @@ static const struct attribute_group vfio_queue_attr_group = {
 };
 
 static const struct vfio_device_ops vfio_ap_matrix_dev_ops = {
+	.init = vfio_ap_mdev_init_dev,
+	.release = vfio_ap_mdev_release_dev,
 	.open_device = vfio_ap_mdev_open_device,
 	.close_device = vfio_ap_mdev_close_device,
 	.ioctl = vfio_ap_mdev_ioctl,
-- 
2.21.3

[PATCH v2 10/15] vfio/fsl-mc: Use the new device life cycle helpers

[Kevin Tian]

From: Yi Liu <yi.l.liu@intel.com>

Also add a comment to mark that vfio core releases device_set if @init
fails.

Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
---
 drivers/vfio/fsl-mc/vfio_fsl_mc.c | 85 ++++++++++++++++++-------------
 1 file changed, 49 insertions(+), 36 deletions(-)

diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc.c b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
index 3feff729f3ce..b6a985b07419 100644
--- a/drivers/vfio/fsl-mc/vfio_fsl_mc.c
+++ b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
@@ -418,16 +418,7 @@ static int vfio_fsl_mc_mmap(struct vfio_device *core_vdev,
 	return vfio_fsl_mc_mmap_mmio(vdev->regions[index], vma);
 }
 
-static const struct vfio_device_ops vfio_fsl_mc_ops = {
-	.name		= "vfio-fsl-mc",
-	.open_device	= vfio_fsl_mc_open_device,
-	.close_device	= vfio_fsl_mc_close_device,
-	.ioctl		= vfio_fsl_mc_ioctl,
-	.read		= vfio_fsl_mc_read,
-	.write		= vfio_fsl_mc_write,
-	.mmap		= vfio_fsl_mc_mmap,
-};
-
+static const struct vfio_device_ops vfio_fsl_mc_ops;
 static int vfio_fsl_mc_bus_notifier(struct notifier_block *nb,
 				    unsigned long action, void *data)
 {
@@ -518,35 +509,43 @@ static void vfio_fsl_uninit_device(struct vfio_fsl_mc_device *vdev)
 	bus_unregister_notifier(&fsl_mc_bus_type, &vdev->nb);
 }
 
-static int vfio_fsl_mc_probe(struct fsl_mc_device *mc_dev)
+static int vfio_fsl_mc_init_dev(struct vfio_device *core_vdev)
 {
-	struct vfio_fsl_mc_device *vdev;
-	struct device *dev = &mc_dev->dev;
+	struct vfio_fsl_mc_device *vdev =
+		container_of(core_vdev, struct vfio_fsl_mc_device, vdev);
+	struct fsl_mc_device *mc_dev = to_fsl_mc_device(core_vdev->dev);
 	int ret;
 
-	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
-	if (!vdev)
-		return -ENOMEM;
-
-	vfio_init_group_dev(&vdev->vdev, dev, &vfio_fsl_mc_ops);
 	vdev->mc_dev = mc_dev;
 	mutex_init(&vdev->igate);
 
 	if (is_fsl_mc_bus_dprc(mc_dev))
-		ret = vfio_assign_device_set(&vdev->vdev, &mc_dev->dev);
+		ret = vfio_assign_device_set(core_vdev, &mc_dev->dev);
 	else
-		ret = vfio_assign_device_set(&vdev->vdev, mc_dev->dev.parent);
-	if (ret)
-		goto out_uninit;
+		ret = vfio_assign_device_set(core_vdev, mc_dev->dev.parent);
 
-	ret = vfio_fsl_mc_init_device(vdev);
 	if (ret)
-		goto out_uninit;
+		return ret;
+
+	/* device_set is released by vfio core if @init fails */
+	return vfio_fsl_mc_init_device(vdev);
+}
+
+static int vfio_fsl_mc_probe(struct fsl_mc_device *mc_dev)
+{
+	struct vfio_fsl_mc_device *vdev;
+	struct device *dev = &mc_dev->dev;
+	int ret;
+
+	vdev = vfio_alloc_device(vfio_fsl_mc_device, vdev, dev,
+				 &vfio_fsl_mc_ops);
+	if (IS_ERR(vdev))
+		return PTR_ERR(vdev);
 
 	ret = vfio_register_group_dev(&vdev->vdev);
 	if (ret) {
 		dev_err(dev, "VFIO_FSL_MC: Failed to add to vfio group\n");
-		goto out_device;
+		goto out_put_vdev;
 	}
 
 	ret = vfio_fsl_mc_scan_container(mc_dev);
@@ -557,30 +556,44 @@ static int vfio_fsl_mc_probe(struct fsl_mc_device *mc_dev)
 
 out_group_dev:
 	vfio_unregister_group_dev(&vdev->vdev);
-out_device:
-	vfio_fsl_uninit_device(vdev);
-out_uninit:
-	vfio_uninit_group_dev(&vdev->vdev);
-	kfree(vdev);
+out_put_vdev:
+	vfio_put_device(&vdev->vdev);
 	return ret;
 }
 
+static void vfio_fsl_mc_release_dev(struct vfio_device *core_vdev)
+{
+	struct vfio_fsl_mc_device *vdev =
+		container_of(core_vdev, struct vfio_fsl_mc_device, vdev);
+
+	vfio_fsl_uninit_device(vdev);
+	mutex_destroy(&vdev->igate);
+	vfio_free_device(core_vdev);
+}
+
 static int vfio_fsl_mc_remove(struct fsl_mc_device *mc_dev)
 {
 	struct device *dev = &mc_dev->dev;
 	struct vfio_fsl_mc_device *vdev = dev_get_drvdata(dev);
 
 	vfio_unregister_group_dev(&vdev->vdev);
-	mutex_destroy(&vdev->igate);
-
 	dprc_remove_devices(mc_dev, NULL, 0);
-	vfio_fsl_uninit_device(vdev);
-
-	vfio_uninit_group_dev(&vdev->vdev);
-	kfree(vdev);
+	vfio_put_device(&vdev->vdev);
 	return 0;
 }
 
+static const struct vfio_device_ops vfio_fsl_mc_ops = {
+	.name		= "vfio-fsl-mc",
+	.init		= vfio_fsl_mc_init_dev,
+	.release	= vfio_fsl_mc_release_dev,
+	.open_device	= vfio_fsl_mc_open_device,
+	.close_device	= vfio_fsl_mc_close_device,
+	.ioctl		= vfio_fsl_mc_ioctl,
+	.read		= vfio_fsl_mc_read,
+	.write		= vfio_fsl_mc_write,
+	.mmap		= vfio_fsl_mc_mmap,
+};
+
 static struct fsl_mc_driver vfio_fsl_mc_driver = {
 	.probe		= vfio_fsl_mc_probe,
 	.remove		= vfio_fsl_mc_remove,
-- 
2.21.3

[PATCH v2 11/15] vfio/platform: Use the new device life cycle helpers

[Kevin Tian]

Move vfio_device_ops from platform core to platform drivers so device
specific init/cleanup can be added.

Introduce two new helpers vfio_platform_init/release_common() for the
use in driver @init/@release.

vfio_platform_probe/remove_common() will be deprecated.

Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
---
 drivers/vfio/platform/vfio_platform.c         | 66 +++++++++++++++----
 drivers/vfio/platform/vfio_platform_common.c  | 53 ++++++++++++---
 drivers/vfio/platform/vfio_platform_private.h | 15 +++++
 3 files changed, 111 insertions(+), 23 deletions(-)

diff --git a/drivers/vfio/platform/vfio_platform.c b/drivers/vfio/platform/vfio_platform.c
index 04f40c5acfd6..82cedcebfd90 100644
--- a/drivers/vfio/platform/vfio_platform.c
+++ b/drivers/vfio/platform/vfio_platform.c
@@ -7,6 +7,7 @@
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/vfio.h>
+#include <linux/pm_runtime.h>
 #include <linux/platform_device.h>
 
 #include "vfio_platform_private.h"
@@ -36,14 +37,11 @@ static int get_platform_irq(struct vfio_platform_device *vdev, int i)
 	return platform_get_irq_optional(pdev, i);
 }
 
-static int vfio_platform_probe(struct platform_device *pdev)
+static int vfio_platform_init_dev(struct vfio_device *core_vdev)
 {
-	struct vfio_platform_device *vdev;
-	int ret;
-
-	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
-	if (!vdev)
-		return -ENOMEM;
+	struct vfio_platform_device *vdev =
+		container_of(core_vdev, struct vfio_platform_device, vdev);
+	struct platform_device *pdev = to_platform_device(core_vdev->dev);
 
 	vdev->opaque = (void *) pdev;
 	vdev->name = pdev->name;
@@ -52,24 +50,64 @@ static int vfio_platform_probe(struct platform_device *pdev)
 	vdev->get_irq = get_platform_irq;
 	vdev->reset_required = reset_required;
 
-	ret = vfio_platform_probe_common(vdev, &pdev->dev);
-	if (ret) {
-		kfree(vdev);
-		return ret;
-	}
+	return vfio_platform_init_common(vdev);
+}
+
+static const struct vfio_device_ops vfio_platform_ops;
+static int vfio_platform_probe(struct platform_device *pdev)
+{
+	struct vfio_platform_device *vdev;
+	int ret;
+
+	vdev = vfio_alloc_device(vfio_platform_device, vdev, &pdev->dev,
+				 &vfio_platform_ops);
+	if (IS_ERR(vdev))
+		return PTR_ERR(vdev);
+
+	ret = vfio_register_group_dev(&vdev->vdev);
+	if (ret)
+		goto out_put_vdev;
+
+	pm_runtime_enable(&pdev->dev);
 	dev_set_drvdata(&pdev->dev, vdev);
 	return 0;
+
+out_put_vdev:
+	vfio_put_device(&vdev->vdev);
+	return ret;
+}
+
+static void vfio_platform_release_dev(struct vfio_device *core_vdev)
+{
+	struct vfio_platform_device *vdev =
+		container_of(core_vdev, struct vfio_platform_device, vdev);
+
+	vfio_platform_release_common(vdev);
+	vfio_free_device(core_vdev);
 }
 
 static int vfio_platform_remove(struct platform_device *pdev)
 {
 	struct vfio_platform_device *vdev = dev_get_drvdata(&pdev->dev);
 
-	vfio_platform_remove_common(vdev);
-	kfree(vdev);
+	vfio_unregister_group_dev(&vdev->vdev);
+	pm_runtime_disable(vdev->device);
+	vfio_put_device(&vdev->vdev);
 	return 0;
 }
 
+static const struct vfio_device_ops vfio_platform_ops = {
+	.name		= "vfio-platform",
+	.init		= vfio_platform_init_dev,
+	.release	= vfio_platform_release_dev,
+	.open_device	= vfio_platform_open_device,
+	.close_device	= vfio_platform_close_device,
+	.ioctl		= vfio_platform_ioctl,
+	.read		= vfio_platform_read,
+	.write		= vfio_platform_write,
+	.mmap		= vfio_platform_mmap,
+};
+
 static struct platform_driver vfio_platform_driver = {
 	.probe		= vfio_platform_probe,
 	.remove		= vfio_platform_remove,
diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
index 256f55b84e70..4c01bf0adebb 100644
--- a/drivers/vfio/platform/vfio_platform_common.c
+++ b/drivers/vfio/platform/vfio_platform_common.c
@@ -218,7 +218,7 @@ static int vfio_platform_call_reset(struct vfio_platform_device *vdev,
 	return -EINVAL;
 }
 
-static void vfio_platform_close_device(struct vfio_device *core_vdev)
+void vfio_platform_close_device(struct vfio_device *core_vdev)
 {
 	struct vfio_platform_device *vdev =
 		container_of(core_vdev, struct vfio_platform_device, vdev);
@@ -236,8 +236,9 @@ static void vfio_platform_close_device(struct vfio_device *core_vdev)
 	vfio_platform_regions_cleanup(vdev);
 	vfio_platform_irq_cleanup(vdev);
 }
+EXPORT_SYMBOL_GPL(vfio_platform_close_device);
 
-static int vfio_platform_open_device(struct vfio_device *core_vdev)
+int vfio_platform_open_device(struct vfio_device *core_vdev)
 {
 	struct vfio_platform_device *vdev =
 		container_of(core_vdev, struct vfio_platform_device, vdev);
@@ -273,9 +274,10 @@ static int vfio_platform_open_device(struct vfio_device *core_vdev)
 	vfio_platform_regions_cleanup(vdev);
 	return ret;
 }
+EXPORT_SYMBOL_GPL(vfio_platform_open_device);
 
-static long vfio_platform_ioctl(struct vfio_device *core_vdev,
-				unsigned int cmd, unsigned long arg)
+long vfio_platform_ioctl(struct vfio_device *core_vdev,
+			 unsigned int cmd, unsigned long arg)
 {
 	struct vfio_platform_device *vdev =
 		container_of(core_vdev, struct vfio_platform_device, vdev);
@@ -382,6 +384,7 @@ static long vfio_platform_ioctl(struct vfio_device *core_vdev,
 
 	return -ENOTTY;
 }
+EXPORT_SYMBOL_GPL(vfio_platform_ioctl);
 
 static ssize_t vfio_platform_read_mmio(struct vfio_platform_region *reg,
 				       char __user *buf, size_t count,
@@ -438,8 +441,8 @@ static ssize_t vfio_platform_read_mmio(struct vfio_platform_region *reg,
 	return -EFAULT;
 }
 
-static ssize_t vfio_platform_read(struct vfio_device *core_vdev,
-				  char __user *buf, size_t count, loff_t *ppos)
+ssize_t vfio_platform_read(struct vfio_device *core_vdev,
+			   char __user *buf, size_t count, loff_t *ppos)
 {
 	struct vfio_platform_device *vdev =
 		container_of(core_vdev, struct vfio_platform_device, vdev);
@@ -460,6 +463,7 @@ static ssize_t vfio_platform_read(struct vfio_device *core_vdev,
 
 	return -EINVAL;
 }
+EXPORT_SYMBOL_GPL(vfio_platform_read);
 
 static ssize_t vfio_platform_write_mmio(struct vfio_platform_region *reg,
 					const char __user *buf, size_t count,
@@ -515,8 +519,8 @@ static ssize_t vfio_platform_write_mmio(struct vfio_platform_region *reg,
 	return -EFAULT;
 }
 
-static ssize_t vfio_platform_write(struct vfio_device *core_vdev, const char __user *buf,
-				   size_t count, loff_t *ppos)
+ssize_t vfio_platform_write(struct vfio_device *core_vdev, const char __user *buf,
+			    size_t count, loff_t *ppos)
 {
 	struct vfio_platform_device *vdev =
 		container_of(core_vdev, struct vfio_platform_device, vdev);
@@ -537,6 +541,7 @@ static ssize_t vfio_platform_write(struct vfio_device *core_vdev, const char __u
 
 	return -EINVAL;
 }
+EXPORT_SYMBOL_GPL(vfio_platform_write);
 
 static int vfio_platform_mmap_mmio(struct vfio_platform_region region,
 				   struct vm_area_struct *vma)
@@ -558,7 +563,7 @@ static int vfio_platform_mmap_mmio(struct vfio_platform_region region,
 			       req_len, vma->vm_page_prot);
 }
 
-static int vfio_platform_mmap(struct vfio_device *core_vdev, struct vm_area_struct *vma)
+int vfio_platform_mmap(struct vfio_device *core_vdev, struct vm_area_struct *vma)
 {
 	struct vfio_platform_device *vdev =
 		container_of(core_vdev, struct vfio_platform_device, vdev);
@@ -598,6 +603,7 @@ static int vfio_platform_mmap(struct vfio_device *core_vdev, struct vm_area_stru
 
 	return -EINVAL;
 }
+EXPORT_SYMBOL_GPL(vfio_platform_mmap);
 
 static const struct vfio_device_ops vfio_platform_ops = {
 	.name		= "vfio-platform",
@@ -639,6 +645,35 @@ static int vfio_platform_of_probe(struct vfio_platform_device *vdev,
  * If the firmware is ACPI type, then acpi_disabled is 0. All other checks are
  * valid checks. We cannot claim that this system is DT.
  */
+int vfio_platform_init_common(struct vfio_platform_device *vdev)
+{
+	int ret;
+	struct device *dev = vdev->vdev.dev;
+
+	ret = vfio_platform_acpi_probe(vdev, dev);
+	if (ret)
+		ret = vfio_platform_of_probe(vdev, dev);
+
+	if (ret)
+		return ret;
+
+	vdev->device = dev;
+	mutex_init(&vdev->igate);
+
+	ret = vfio_platform_get_reset(vdev);
+	if (ret && vdev->reset_required)
+		dev_err(dev, "No reset function found for device %s\n",
+			vdev->name);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(vfio_platform_init_common);
+
+void vfio_platform_release_common(struct vfio_platform_device *vdev)
+{
+	vfio_platform_put_reset(vdev);
+}
+EXPORT_SYMBOL_GPL(vfio_platform_release_common);
+
 int vfio_platform_probe_common(struct vfio_platform_device *vdev,
 			       struct device *dev)
 {
diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h
index 691b43f4b2b2..a769d649fb97 100644
--- a/drivers/vfio/platform/vfio_platform_private.h
+++ b/drivers/vfio/platform/vfio_platform_private.h
@@ -81,6 +81,21 @@ struct vfio_platform_reset_node {
 int vfio_platform_probe_common(struct vfio_platform_device *vdev,
 			       struct device *dev);
 void vfio_platform_remove_common(struct vfio_platform_device *vdev);
+int vfio_platform_init_common(struct vfio_platform_device *vdev);
+void vfio_platform_release_common(struct vfio_platform_device *vdev);
+
+int vfio_platform_open_device(struct vfio_device *core_vdev);
+void vfio_platform_close_device(struct vfio_device *core_vdev);
+long vfio_platform_ioctl(struct vfio_device *core_vdev,
+			 unsigned int cmd, unsigned long arg);
+ssize_t vfio_platform_read(struct vfio_device *core_vdev,
+			   char __user *buf, size_t count,
+			   loff_t *ppos);
+ssize_t vfio_platform_write(struct vfio_device *core_vdev,
+			    const char __user *buf,
+			    size_t count, loff_t *ppos);
+int vfio_platform_mmap(struct vfio_device *core_vdev,
+		       struct vm_area_struct *vma);
 
 int vfio_platform_irq_init(struct vfio_platform_device *vdev);
 void vfio_platform_irq_cleanup(struct vfio_platform_device *vdev);
-- 
2.21.3

Re: [PATCH v2 11/15] vfio/platform: Use the new device life cycle helpers

[Eric Auger]

Hi kevin,

On 9/1/22 16:37, Kevin Tian wrote:
> Move vfio_device_ops from platform core to platform drivers so device
> specific init/cleanup can be added.
>
> Introduce two new helpers vfio_platform_init/release_common() for the
> use in driver @init/@release.
>
> vfio_platform_probe/remove_common() will be deprecated.
>
> Signed-off-by: Kevin Tian <kevin.tian@intel.com>
> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
> ---
>  drivers/vfio/platform/vfio_platform.c         | 66 +++++++++++++++----
>  drivers/vfio/platform/vfio_platform_common.c  | 53 ++++++++++++---
>  drivers/vfio/platform/vfio_platform_private.h | 15 +++++
>  3 files changed, 111 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/vfio/platform/vfio_platform.c b/drivers/vfio/platform/vfio_platform.c
> index 04f40c5acfd6..82cedcebfd90 100644
> --- a/drivers/vfio/platform/vfio_platform.c
> +++ b/drivers/vfio/platform/vfio_platform.c
> @@ -7,6 +7,7 @@
>  #include <linux/module.h>
>  #include <linux/slab.h>
>  #include <linux/vfio.h>
> +#include <linux/pm_runtime.h>
>  #include <linux/platform_device.h>
>  
>  #include "vfio_platform_private.h"
> @@ -36,14 +37,11 @@ static int get_platform_irq(struct vfio_platform_device *vdev, int i)
>  	return platform_get_irq_optional(pdev, i);
>  }
>  
> -static int vfio_platform_probe(struct platform_device *pdev)
> +static int vfio_platform_init_dev(struct vfio_device *core_vdev)
>  {
> -	struct vfio_platform_device *vdev;
> -	int ret;
> -
> -	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
> -	if (!vdev)
> -		return -ENOMEM;
> +	struct vfio_platform_device *vdev =
> +		container_of(core_vdev, struct vfio_platform_device, vdev);
> +	struct platform_device *pdev = to_platform_device(core_vdev->dev);
>  
>  	vdev->opaque = (void *) pdev;
>  	vdev->name = pdev->name;
> @@ -52,24 +50,64 @@ static int vfio_platform_probe(struct platform_device *pdev)
>  	vdev->get_irq = get_platform_irq;
>  	vdev->reset_required = reset_required;
>  
> -	ret = vfio_platform_probe_common(vdev, &pdev->dev);
> -	if (ret) {
> -		kfree(vdev);
> -		return ret;
> -	}
> +	return vfio_platform_init_common(vdev);
> +}
> +
> +static const struct vfio_device_ops vfio_platform_ops;
> +static int vfio_platform_probe(struct platform_device *pdev)
> +{
> +	struct vfio_platform_device *vdev;
> +	int ret;
> +
> +	vdev = vfio_alloc_device(vfio_platform_device, vdev, &pdev->dev,
> +				 &vfio_platform_ops);
> +	if (IS_ERR(vdev))
> +		return PTR_ERR(vdev);
> +
> +	ret = vfio_register_group_dev(&vdev->vdev);
> +	if (ret)
> +		goto out_put_vdev;
> +
> +	pm_runtime_enable(&pdev->dev);
>  	dev_set_drvdata(&pdev->dev, vdev);
>  	return 0;
> +
> +out_put_vdev:
> +	vfio_put_device(&vdev->vdev);
> +	return ret;
> +}
> +
> +static void vfio_platform_release_dev(struct vfio_device *core_vdev)
> +{
> +	struct vfio_platform_device *vdev =
> +		container_of(core_vdev, struct vfio_platform_device, vdev);
> +
> +	vfio_platform_release_common(vdev);
> +	vfio_free_device(core_vdev);
>  }
>  
>  static int vfio_platform_remove(struct platform_device *pdev)
>  {
>  	struct vfio_platform_device *vdev = dev_get_drvdata(&pdev->dev);
>  
> -	vfio_platform_remove_common(vdev);
> -	kfree(vdev);
> +	vfio_unregister_group_dev(&vdev->vdev);
> +	pm_runtime_disable(vdev->device);
> +	vfio_put_device(&vdev->vdev);
>  	return 0;
>  }
>  
> +static const struct vfio_device_ops vfio_platform_ops = {
> +	.name		= "vfio-platform",
> +	.init		= vfio_platform_init_dev,
> +	.release	= vfio_platform_release_dev,
> +	.open_device	= vfio_platform_open_device,
> +	.close_device	= vfio_platform_close_device,
> +	.ioctl		= vfio_platform_ioctl,
> +	.read		= vfio_platform_read,
> +	.write		= vfio_platform_write,
> +	.mmap		= vfio_platform_mmap,
> +};
> +
>  static struct platform_driver vfio_platform_driver = {
>  	.probe		= vfio_platform_probe,
>  	.remove		= vfio_platform_remove,
> diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
> index 256f55b84e70..4c01bf0adebb 100644
> --- a/drivers/vfio/platform/vfio_platform_common.c
> +++ b/drivers/vfio/platform/vfio_platform_common.c
> @@ -218,7 +218,7 @@ static int vfio_platform_call_reset(struct vfio_platform_device *vdev,
>  	return -EINVAL;
>  }
>  
> -static void vfio_platform_close_device(struct vfio_device *core_vdev)
> +void vfio_platform_close_device(struct vfio_device *core_vdev)
>  {
>  	struct vfio_platform_device *vdev =
>  		container_of(core_vdev, struct vfio_platform_device, vdev);
> @@ -236,8 +236,9 @@ static void vfio_platform_close_device(struct vfio_device *core_vdev)
>  	vfio_platform_regions_cleanup(vdev);
>  	vfio_platform_irq_cleanup(vdev);
>  }
> +EXPORT_SYMBOL_GPL(vfio_platform_close_device);
>  
> -static int vfio_platform_open_device(struct vfio_device *core_vdev)
> +int vfio_platform_open_device(struct vfio_device *core_vdev)
>  {
>  	struct vfio_platform_device *vdev =
>  		container_of(core_vdev, struct vfio_platform_device, vdev);
> @@ -273,9 +274,10 @@ static int vfio_platform_open_device(struct vfio_device *core_vdev)
>  	vfio_platform_regions_cleanup(vdev);
>  	return ret;
>  }
> +EXPORT_SYMBOL_GPL(vfio_platform_open_device);
>  
> -static long vfio_platform_ioctl(struct vfio_device *core_vdev,
> -				unsigned int cmd, unsigned long arg)
> +long vfio_platform_ioctl(struct vfio_device *core_vdev,
> +			 unsigned int cmd, unsigned long arg)
>  {
>  	struct vfio_platform_device *vdev =
>  		container_of(core_vdev, struct vfio_platform_device, vdev);
> @@ -382,6 +384,7 @@ static long vfio_platform_ioctl(struct vfio_device *core_vdev,
>  
>  	return -ENOTTY;
>  }
> +EXPORT_SYMBOL_GPL(vfio_platform_ioctl);
>  
>  static ssize_t vfio_platform_read_mmio(struct vfio_platform_region *reg,
>  				       char __user *buf, size_t count,
> @@ -438,8 +441,8 @@ static ssize_t vfio_platform_read_mmio(struct vfio_platform_region *reg,
>  	return -EFAULT;
>  }
>  
> -static ssize_t vfio_platform_read(struct vfio_device *core_vdev,
> -				  char __user *buf, size_t count, loff_t *ppos)
> +ssize_t vfio_platform_read(struct vfio_device *core_vdev,
> +			   char __user *buf, size_t count, loff_t *ppos)
>  {
>  	struct vfio_platform_device *vdev =
>  		container_of(core_vdev, struct vfio_platform_device, vdev);
> @@ -460,6 +463,7 @@ static ssize_t vfio_platform_read(struct vfio_device *core_vdev,
>  
>  	return -EINVAL;
>  }
> +EXPORT_SYMBOL_GPL(vfio_platform_read);
>  
>  static ssize_t vfio_platform_write_mmio(struct vfio_platform_region *reg,
>  					const char __user *buf, size_t count,
> @@ -515,8 +519,8 @@ static ssize_t vfio_platform_write_mmio(struct vfio_platform_region *reg,
>  	return -EFAULT;
>  }
>  
> -static ssize_t vfio_platform_write(struct vfio_device *core_vdev, const char __user *buf,
> -				   size_t count, loff_t *ppos)
> +ssize_t vfio_platform_write(struct vfio_device *core_vdev, const char __user *buf,
> +			    size_t count, loff_t *ppos)
>  {
>  	struct vfio_platform_device *vdev =
>  		container_of(core_vdev, struct vfio_platform_device, vdev);
> @@ -537,6 +541,7 @@ static ssize_t vfio_platform_write(struct vfio_device *core_vdev, const char __u
>  
>  	return -EINVAL;
>  }
> +EXPORT_SYMBOL_GPL(vfio_platform_write);
>  
>  static int vfio_platform_mmap_mmio(struct vfio_platform_region region,
>  				   struct vm_area_struct *vma)
> @@ -558,7 +563,7 @@ static int vfio_platform_mmap_mmio(struct vfio_platform_region region,
>  			       req_len, vma->vm_page_prot);
>  }
>  
> -static int vfio_platform_mmap(struct vfio_device *core_vdev, struct vm_area_struct *vma)
> +int vfio_platform_mmap(struct vfio_device *core_vdev, struct vm_area_struct *vma)
>  {
>  	struct vfio_platform_device *vdev =
>  		container_of(core_vdev, struct vfio_platform_device, vdev);
> @@ -598,6 +603,7 @@ static int vfio_platform_mmap(struct vfio_device *core_vdev, struct vm_area_stru
>  
>  	return -EINVAL;
>  }
> +EXPORT_SYMBOL_GPL(vfio_platform_mmap);
>  
>  static const struct vfio_device_ops vfio_platform_ops = {
>  	.name		= "vfio-platform",
> @@ -639,6 +645,35 @@ static int vfio_platform_of_probe(struct vfio_platform_device *vdev,
>   * If the firmware is ACPI type, then acpi_disabled is 0. All other checks are
>   * valid checks. We cannot claim that this system is DT.
>   */
> +int vfio_platform_init_common(struct vfio_platform_device *vdev)
> +{
> +	int ret;
> +	struct device *dev = vdev->vdev.dev;
> +
> +	ret = vfio_platform_acpi_probe(vdev, dev);
> +	if (ret)
> +		ret = vfio_platform_of_probe(vdev, dev);
> +
> +	if (ret)
> +		return ret;
> +
> +	vdev->device = dev;
> +	mutex_init(&vdev->igate);
> +
> +	ret = vfio_platform_get_reset(vdev);
> +	if (ret && vdev->reset_required)
> +		dev_err(dev, "No reset function found for device %s\n",
> +			vdev->name);
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(vfio_platform_init_common);
> +
> +void vfio_platform_release_common(struct vfio_platform_device *vdev)
> +{
> +	vfio_platform_put_reset(vdev);
> +}
> +EXPORT_SYMBOL_GPL(vfio_platform_release_common);
> +
>  int vfio_platform_probe_common(struct vfio_platform_device *vdev,
>  			       struct device *dev)
>  {
> diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h
> index 691b43f4b2b2..a769d649fb97 100644
> --- a/drivers/vfio/platform/vfio_platform_private.h
> +++ b/drivers/vfio/platform/vfio_platform_private.h
> @@ -81,6 +81,21 @@ struct vfio_platform_reset_node {
>  int vfio_platform_probe_common(struct vfio_platform_device *vdev,
>  			       struct device *dev);
>  void vfio_platform_remove_common(struct vfio_platform_device *vdev);
> +int vfio_platform_init_common(struct vfio_platform_device *vdev);
> +void vfio_platform_release_common(struct vfio_platform_device *vdev);
> +
> +int vfio_platform_open_device(struct vfio_device *core_vdev);
> +void vfio_platform_close_device(struct vfio_device *core_vdev);
> +long vfio_platform_ioctl(struct vfio_device *core_vdev,
> +			 unsigned int cmd, unsigned long arg);
> +ssize_t vfio_platform_read(struct vfio_device *core_vdev,
> +			   char __user *buf, size_t count,
> +			   loff_t *ppos);
> +ssize_t vfio_platform_write(struct vfio_device *core_vdev,
> +			    const char __user *buf,
> +			    size_t count, loff_t *ppos);
> +int vfio_platform_mmap(struct vfio_device *core_vdev,
> +		       struct vm_area_struct *vma);
>  
>  int vfio_platform_irq_init(struct vfio_platform_device *vdev);
>  void vfio_platform_irq_cleanup(struct vfio_platform_device *vdev);
Looks good to me. I also ran basic non regression testing

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Eric Auger <eric.auger@redhat.com>

Eric

[PATCH v2 12/15] vfio/amba: Use the new device life cycle helpers

[Kevin Tian]

Implement amba's own vfio_device_ops.

Remove vfio_platform_probe/remove_common() given no user now.

Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
---
 drivers/vfio/platform/vfio_amba.c             | 72 ++++++++++++++-----
 drivers/vfio/platform/vfio_platform_common.c  | 60 ----------------
 drivers/vfio/platform/vfio_platform_private.h |  3 -
 3 files changed, 55 insertions(+), 80 deletions(-)

diff --git a/drivers/vfio/platform/vfio_amba.c b/drivers/vfio/platform/vfio_amba.c
index 1aaa4f721bd2..6cdcc8905198 100644
--- a/drivers/vfio/platform/vfio_amba.c
+++ b/drivers/vfio/platform/vfio_amba.c
@@ -7,6 +7,7 @@
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/vfio.h>
+#include <linux/pm_runtime.h>
 #include <linux/amba/bus.h>
 
 #include "vfio_platform_private.h"
@@ -40,20 +41,16 @@ static int get_amba_irq(struct vfio_platform_device *vdev, int i)
 	return ret ? ret : -ENXIO;
 }
 
-static int vfio_amba_probe(struct amba_device *adev, const struct amba_id *id)
+static int vfio_amba_init_dev(struct vfio_device *core_vdev)
 {
-	struct vfio_platform_device *vdev;
+	struct vfio_platform_device *vdev =
+		container_of(core_vdev, struct vfio_platform_device, vdev);
+	struct amba_device *adev = to_amba_device(core_vdev->dev);
 	int ret;
 
-	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
-	if (!vdev)
-		return -ENOMEM;
-
 	vdev->name = kasprintf(GFP_KERNEL, "vfio-amba-%08x", adev->periphid);
-	if (!vdev->name) {
-		kfree(vdev);
+	if (!vdev->name)
 		return -ENOMEM;
-	}
 
 	vdev->opaque = (void *) adev;
 	vdev->flags = VFIO_DEVICE_FLAGS_AMBA;
@@ -61,26 +58,67 @@ static int vfio_amba_probe(struct amba_device *adev, const struct amba_id *id)
 	vdev->get_irq = get_amba_irq;
 	vdev->reset_required = false;
 
-	ret = vfio_platform_probe_common(vdev, &adev->dev);
-	if (ret) {
+	ret = vfio_platform_init_common(vdev);
+	if (ret)
 		kfree(vdev->name);
-		kfree(vdev);
-		return ret;
-	}
+	return ret;
+}
+
+static const struct vfio_device_ops vfio_amba_ops;
+static int vfio_amba_probe(struct amba_device *adev, const struct amba_id *id)
+{
+	struct vfio_platform_device *vdev;
+	int ret;
+
+	vdev = vfio_alloc_device(vfio_platform_device, vdev, &adev->dev,
+				 &vfio_amba_ops);
+	if (IS_ERR(vdev))
+		return PTR_ERR(vdev);
 
+	ret = vfio_register_group_dev(&vdev->vdev);
+	if (ret)
+		goto out_put_vdev;
+
+	pm_runtime_enable(&adev->dev);
 	dev_set_drvdata(&adev->dev, vdev);
 	return 0;
+
+out_put_vdev:
+	vfio_put_device(&vdev->vdev);
+	return ret;
+}
+
+static void vfio_amba_release_dev(struct vfio_device *core_vdev)
+{
+	struct vfio_platform_device *vdev =
+		container_of(core_vdev, struct vfio_platform_device, vdev);
+
+	vfio_platform_release_common(vdev);
+	kfree(vdev->name);
+	vfio_free_device(core_vdev);
 }
 
 static void vfio_amba_remove(struct amba_device *adev)
 {
 	struct vfio_platform_device *vdev = dev_get_drvdata(&adev->dev);
 
-	vfio_platform_remove_common(vdev);
-	kfree(vdev->name);
-	kfree(vdev);
+	vfio_unregister_group_dev(&vdev->vdev);
+	pm_runtime_disable(vdev->device);
+	vfio_put_device(&vdev->vdev);
 }
 
+static const struct vfio_device_ops vfio_amba_ops= {
+	.name		= "vfio-amba",
+	.init		= vfio_amba_init_dev,
+	.release	= vfio_amba_release_dev,
+	.open_device	= vfio_platform_open_device,
+	.close_device	= vfio_platform_close_device,
+	.ioctl		= vfio_platform_ioctl,
+	.read		= vfio_platform_read,
+	.write		= vfio_platform_write,
+	.mmap		= vfio_platform_mmap,
+};
+
 static const struct amba_id pl330_ids[] = {
 	{ 0, 0 },
 };
diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
index 4c01bf0adebb..55dc4f43c31e 100644
--- a/drivers/vfio/platform/vfio_platform_common.c
+++ b/drivers/vfio/platform/vfio_platform_common.c
@@ -605,16 +605,6 @@ int vfio_platform_mmap(struct vfio_device *core_vdev, struct vm_area_struct *vma
 }
 EXPORT_SYMBOL_GPL(vfio_platform_mmap);
 
-static const struct vfio_device_ops vfio_platform_ops = {
-	.name		= "vfio-platform",
-	.open_device	= vfio_platform_open_device,
-	.close_device	= vfio_platform_close_device,
-	.ioctl		= vfio_platform_ioctl,
-	.read		= vfio_platform_read,
-	.write		= vfio_platform_write,
-	.mmap		= vfio_platform_mmap,
-};
-
 static int vfio_platform_of_probe(struct vfio_platform_device *vdev,
 			   struct device *dev)
 {
@@ -674,56 +664,6 @@ void vfio_platform_release_common(struct vfio_platform_device *vdev)
 }
 EXPORT_SYMBOL_GPL(vfio_platform_release_common);
 
-int vfio_platform_probe_common(struct vfio_platform_device *vdev,
-			       struct device *dev)
-{
-	int ret;
-
-	vfio_init_group_dev(&vdev->vdev, dev, &vfio_platform_ops);
-
-	ret = vfio_platform_acpi_probe(vdev, dev);
-	if (ret)
-		ret = vfio_platform_of_probe(vdev, dev);
-
-	if (ret)
-		goto out_uninit;
-
-	vdev->device = dev;
-
-	ret = vfio_platform_get_reset(vdev);
-	if (ret && vdev->reset_required) {
-		dev_err(dev, "No reset function found for device %s\n",
-			vdev->name);
-		goto out_uninit;
-	}
-
-	ret = vfio_register_group_dev(&vdev->vdev);
-	if (ret)
-		goto put_reset;
-
-	mutex_init(&vdev->igate);
-
-	pm_runtime_enable(dev);
-	return 0;
-
-put_reset:
-	vfio_platform_put_reset(vdev);
-out_uninit:
-	vfio_uninit_group_dev(&vdev->vdev);
-	return ret;
-}
-EXPORT_SYMBOL_GPL(vfio_platform_probe_common);
-
-void vfio_platform_remove_common(struct vfio_platform_device *vdev)
-{
-	vfio_unregister_group_dev(&vdev->vdev);
-
-	pm_runtime_disable(vdev->device);
-	vfio_platform_put_reset(vdev);
-	vfio_uninit_group_dev(&vdev->vdev);
-}
-EXPORT_SYMBOL_GPL(vfio_platform_remove_common);
-
 void __vfio_platform_register_reset(struct vfio_platform_reset_node *node)
 {
 	mutex_lock(&driver_lock);
diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h
index a769d649fb97..8d8fab516849 100644
--- a/drivers/vfio/platform/vfio_platform_private.h
+++ b/drivers/vfio/platform/vfio_platform_private.h
@@ -78,9 +78,6 @@ struct vfio_platform_reset_node {
 	vfio_platform_reset_fn_t of_reset;
 };
 
-int vfio_platform_probe_common(struct vfio_platform_device *vdev,
-			       struct device *dev);
-void vfio_platform_remove_common(struct vfio_platform_device *vdev);
 int vfio_platform_init_common(struct vfio_platform_device *vdev);
 void vfio_platform_release_common(struct vfio_platform_device *vdev);
 
-- 
2.21.3

RE: [PATCH v2 12/15] vfio/amba: Use the new device life cycle helpers

[Tian, Kevin]

> From: Tian, Kevin <kevin.tian@intel.com>
> Sent: Thursday, September 1, 2022 10:38 PM
> 
> +static const struct vfio_device_ops vfio_amba_ops= {

Above missed a space after vfio_amba_ops.

Re: [PATCH v2 12/15] vfio/amba: Use the new device life cycle helpers

[Eric Auger]

Hi Kevin,

On 9/1/22 16:37, Kevin Tian wrote:
> Implement amba's own vfio_device_ops.
>
> Remove vfio_platform_probe/remove_common() given no user now.
>
> Signed-off-by: Kevin Tian <kevin.tian@intel.com>
> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
> ---
>  drivers/vfio/platform/vfio_amba.c             | 72 ++++++++++++++-----
>  drivers/vfio/platform/vfio_platform_common.c  | 60 ----------------
>  drivers/vfio/platform/vfio_platform_private.h |  3 -
>  3 files changed, 55 insertions(+), 80 deletions(-)
>
> diff --git a/drivers/vfio/platform/vfio_amba.c b/drivers/vfio/platform/vfio_amba.c
> index 1aaa4f721bd2..6cdcc8905198 100644
> --- a/drivers/vfio/platform/vfio_amba.c
> +++ b/drivers/vfio/platform/vfio_amba.c
> @@ -7,6 +7,7 @@
>  #include <linux/module.h>
>  #include <linux/slab.h>
>  #include <linux/vfio.h>
> +#include <linux/pm_runtime.h>
>  #include <linux/amba/bus.h>
>  
>  #include "vfio_platform_private.h"
> @@ -40,20 +41,16 @@ static int get_amba_irq(struct vfio_platform_device *vdev, int i)
>  	return ret ? ret : -ENXIO;
>  }
>  
> -static int vfio_amba_probe(struct amba_device *adev, const struct amba_id *id)
> +static int vfio_amba_init_dev(struct vfio_device *core_vdev)
>  {
> -	struct vfio_platform_device *vdev;
> +	struct vfio_platform_device *vdev =
> +		container_of(core_vdev, struct vfio_platform_device, vdev);
> +	struct amba_device *adev = to_amba_device(core_vdev->dev);
>  	int ret;
>  
> -	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
> -	if (!vdev)
> -		return -ENOMEM;
> -
>  	vdev->name = kasprintf(GFP_KERNEL, "vfio-amba-%08x", adev->periphid);
> -	if (!vdev->name) {
> -		kfree(vdev);
> +	if (!vdev->name)
>  		return -ENOMEM;
> -	}
>  
>  	vdev->opaque = (void *) adev;
>  	vdev->flags = VFIO_DEVICE_FLAGS_AMBA;
> @@ -61,26 +58,67 @@ static int vfio_amba_probe(struct amba_device *adev, const struct amba_id *id)
>  	vdev->get_irq = get_amba_irq;
>  	vdev->reset_required = false;
>  
> -	ret = vfio_platform_probe_common(vdev, &adev->dev);
> -	if (ret) {
> +	ret = vfio_platform_init_common(vdev);
> +	if (ret)
>  		kfree(vdev->name);
> -		kfree(vdev);
> -		return ret;
> -	}
> +	return ret;
> +}
> +
> +static const struct vfio_device_ops vfio_amba_ops;
> +static int vfio_amba_probe(struct amba_device *adev, const struct amba_id *id)
> +{
> +	struct vfio_platform_device *vdev;
> +	int ret;
> +
> +	vdev = vfio_alloc_device(vfio_platform_device, vdev, &adev->dev,
> +				 &vfio_amba_ops);
> +	if (IS_ERR(vdev))
> +		return PTR_ERR(vdev);
>  
> +	ret = vfio_register_group_dev(&vdev->vdev);
> +	if (ret)
> +		goto out_put_vdev;
> +
> +	pm_runtime_enable(&adev->dev);
>  	dev_set_drvdata(&adev->dev, vdev);
>  	return 0;
> +
> +out_put_vdev:
> +	vfio_put_device(&vdev->vdev);
> +	return ret;
> +}
> +
> +static void vfio_amba_release_dev(struct vfio_device *core_vdev)
> +{
> +	struct vfio_platform_device *vdev =
> +		container_of(core_vdev, struct vfio_platform_device, vdev);
> +
> +	vfio_platform_release_common(vdev);
> +	kfree(vdev->name);
> +	vfio_free_device(core_vdev);
>  }
>  
>  static void vfio_amba_remove(struct amba_device *adev)
>  {
>  	struct vfio_platform_device *vdev = dev_get_drvdata(&adev->dev);
>  
> -	vfio_platform_remove_common(vdev);
> -	kfree(vdev->name);
> -	kfree(vdev);
> +	vfio_unregister_group_dev(&vdev->vdev);
> +	pm_runtime_disable(vdev->device);
> +	vfio_put_device(&vdev->vdev);
>  }
>  
> +static const struct vfio_device_ops vfio_amba_ops= {
> +	.name		= "vfio-amba",
> +	.init		= vfio_amba_init_dev,
> +	.release	= vfio_amba_release_dev,
> +	.open_device	= vfio_platform_open_device,
> +	.close_device	= vfio_platform_close_device,
> +	.ioctl		= vfio_platform_ioctl,
> +	.read		= vfio_platform_read,
> +	.write		= vfio_platform_write,
> +	.mmap		= vfio_platform_mmap,
> +};
> +
>  static const struct amba_id pl330_ids[] = {
>  	{ 0, 0 },
>  };
> diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
> index 4c01bf0adebb..55dc4f43c31e 100644
> --- a/drivers/vfio/platform/vfio_platform_common.c
> +++ b/drivers/vfio/platform/vfio_platform_common.c
> @@ -605,16 +605,6 @@ int vfio_platform_mmap(struct vfio_device *core_vdev, struct vm_area_struct *vma
>  }
>  EXPORT_SYMBOL_GPL(vfio_platform_mmap);
>  
> -static const struct vfio_device_ops vfio_platform_ops = {
> -	.name		= "vfio-platform",
> -	.open_device	= vfio_platform_open_device,
> -	.close_device	= vfio_platform_close_device,
> -	.ioctl		= vfio_platform_ioctl,
> -	.read		= vfio_platform_read,
> -	.write		= vfio_platform_write,
> -	.mmap		= vfio_platform_mmap,
> -};
> -
>  static int vfio_platform_of_probe(struct vfio_platform_device *vdev,
>  			   struct device *dev)
>  {
> @@ -674,56 +664,6 @@ void vfio_platform_release_common(struct vfio_platform_device *vdev)
>  }
>  EXPORT_SYMBOL_GPL(vfio_platform_release_common);
>  
> -int vfio_platform_probe_common(struct vfio_platform_device *vdev,
> -			       struct device *dev)
> -{
> -	int ret;
> -
> -	vfio_init_group_dev(&vdev->vdev, dev, &vfio_platform_ops);
> -
> -	ret = vfio_platform_acpi_probe(vdev, dev);
> -	if (ret)
> -		ret = vfio_platform_of_probe(vdev, dev);
> -
> -	if (ret)
> -		goto out_uninit;
> -
> -	vdev->device = dev;
> -
> -	ret = vfio_platform_get_reset(vdev);
> -	if (ret && vdev->reset_required) {
> -		dev_err(dev, "No reset function found for device %s\n",
> -			vdev->name);
> -		goto out_uninit;
> -	}
> -
> -	ret = vfio_register_group_dev(&vdev->vdev);
> -	if (ret)
> -		goto put_reset;
> -
> -	mutex_init(&vdev->igate);
> -
> -	pm_runtime_enable(dev);
> -	return 0;
> -
> -put_reset:
> -	vfio_platform_put_reset(vdev);
> -out_uninit:
> -	vfio_uninit_group_dev(&vdev->vdev);
> -	return ret;
> -}
> -EXPORT_SYMBOL_GPL(vfio_platform_probe_common);
> -
> -void vfio_platform_remove_common(struct vfio_platform_device *vdev)
> -{
> -	vfio_unregister_group_dev(&vdev->vdev);
> -
> -	pm_runtime_disable(vdev->device);
> -	vfio_platform_put_reset(vdev);
> -	vfio_uninit_group_dev(&vdev->vdev);
> -}
> -EXPORT_SYMBOL_GPL(vfio_platform_remove_common);
> -
>  void __vfio_platform_register_reset(struct vfio_platform_reset_node *node)
>  {
>  	mutex_lock(&driver_lock);
> diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h
> index a769d649fb97..8d8fab516849 100644
> --- a/drivers/vfio/platform/vfio_platform_private.h
> +++ b/drivers/vfio/platform/vfio_platform_private.h
> @@ -78,9 +78,6 @@ struct vfio_platform_reset_node {
>  	vfio_platform_reset_fn_t of_reset;
>  };
>  
> -int vfio_platform_probe_common(struct vfio_platform_device *vdev,
> -			       struct device *dev);
> -void vfio_platform_remove_common(struct vfio_platform_device *vdev);
>  int vfio_platform_init_common(struct vfio_platform_device *vdev);
>  void vfio_platform_release_common(struct vfio_platform_device *vdev);
>  
Reviewed-by: Eric Auger <eric.auger@redhat.com>

Eric

[PATCH v2 13/15] vfio/ccw: Use the new device life cycle helpers

[Kevin Tian]

ccw is the only exception which cannot use vfio_alloc_device() because
its private device structure is designed to serve both mdev and parent.
Life cycle of the parent is managed by css_driver so vfio_ccw_private
must be allocated/freed in css_driver probe/remove path instead of
conforming to vfio core life cycle for mdev.

Given that use a wait/completion scheme so the mdev remove path waits
after vfio_put_device() until receiving a completion notification from
@release. The completion indicates that all active references on
vfio_device have been released.

After that point although free of vfio_ccw_private is delayed to
css_driver it's at least guaranteed to have no parallel reference on
released vfio device part from other code paths.

memset() in @probe is removed. vfio_device is either already cleared
when probed for the first time or cleared in @release from last probe.

The right fix is to introduce separate structures for mdev and parent,
but this won't happen in short term per prior discussions.

Remove vfio_init/uninit_group_dev() as no user now.

Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
---
 drivers/s390/cio/vfio_ccw_ops.c     | 52 +++++++++++++++++++++++++----
 drivers/s390/cio/vfio_ccw_private.h |  3 ++
 drivers/vfio/vfio_main.c            | 23 +++----------
 include/linux/vfio.h                |  3 --
 4 files changed, 53 insertions(+), 28 deletions(-)

diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c
index 4a806a2273b5..9f8486c0d3d3 100644
--- a/drivers/s390/cio/vfio_ccw_ops.c
+++ b/drivers/s390/cio/vfio_ccw_ops.c
@@ -87,6 +87,15 @@ static struct attribute_group *mdev_type_groups[] = {
 	NULL,
 };
 
+static int vfio_ccw_mdev_init_dev(struct vfio_device *vdev)
+{
+	struct vfio_ccw_private *private =
+		container_of(vdev, struct vfio_ccw_private, vdev);
+
+	init_completion(&private->release_comp);
+	return 0;
+}
+
 static int vfio_ccw_mdev_probe(struct mdev_device *mdev)
 {
 	struct vfio_ccw_private *private = dev_get_drvdata(mdev->dev.parent);
@@ -98,9 +107,9 @@ static int vfio_ccw_mdev_probe(struct mdev_device *mdev)
 	if (atomic_dec_if_positive(&private->avail) < 0)
 		return -EPERM;
 
-	memset(&private->vdev, 0, sizeof(private->vdev));
-	vfio_init_group_dev(&private->vdev, &mdev->dev,
-			    &vfio_ccw_dev_ops);
+	ret = vfio_init_device(&private->vdev, &mdev->dev, &vfio_ccw_dev_ops);
+	if (ret)
+		return ret;
 
 	VFIO_CCW_MSG_EVENT(2, "sch %x.%x.%04x: create\n",
 			   private->sch->schid.cssid,
@@ -109,16 +118,33 @@ static int vfio_ccw_mdev_probe(struct mdev_device *mdev)
 
 	ret = vfio_register_emulated_iommu_dev(&private->vdev);
 	if (ret)
-		goto err_atomic;
+		goto err_put_vdev;
 	dev_set_drvdata(&mdev->dev, private);
 	return 0;
 
-err_atomic:
-	vfio_uninit_group_dev(&private->vdev);
+err_put_vdev:
+	vfio_put_device(&private->vdev);
 	atomic_inc(&private->avail);
 	return ret;
 }
 
+static void vfio_ccw_mdev_release_dev(struct vfio_device *vdev)
+{
+	struct vfio_ccw_private *private =
+		container_of(vdev, struct vfio_ccw_private, vdev);
+
+	/*
+	 * We cannot free vfio_ccw_private here because it includes
+	 * parent info which must be free'ed by css driver.
+	 *
+	 * Use a workaround by memset'ing the core device part and
+	 * then notifying the remove path that all active references
+	 * to this device have been released.
+	 */
+	memset(vdev, 0, sizeof(*vdev));
+	complete(&private->release_comp);
+}
+
 static void vfio_ccw_mdev_remove(struct mdev_device *mdev)
 {
 	struct vfio_ccw_private *private = dev_get_drvdata(mdev->dev.parent);
@@ -130,7 +156,17 @@ static void vfio_ccw_mdev_remove(struct mdev_device *mdev)
 
 	vfio_unregister_group_dev(&private->vdev);
 
-	vfio_uninit_group_dev(&private->vdev);
+	vfio_put_device(&private->vdev);
+	/*
+	 * Wait for all active references on mdev are released so it
+	 * is safe to defer kfree() to a later point.
+	 *
+	 * TODO: the clean fix is to split parent/mdev info from ccw
+	 * private structure so each can be managed in its own life
+	 * cycle.
+	 */
+	wait_for_completion(&private->release_comp);
+
 	atomic_inc(&private->avail);
 }
 
@@ -592,6 +628,8 @@ static void vfio_ccw_mdev_request(struct vfio_device *vdev, unsigned int count)
 }
 
 static const struct vfio_device_ops vfio_ccw_dev_ops = {
+	.init = vfio_ccw_mdev_init_dev,
+	.release = vfio_ccw_mdev_release_dev,
 	.open_device = vfio_ccw_mdev_open_device,
 	.close_device = vfio_ccw_mdev_close_device,
 	.read = vfio_ccw_mdev_read,
diff --git a/drivers/s390/cio/vfio_ccw_private.h b/drivers/s390/cio/vfio_ccw_private.h
index cd24b7fada91..63d9202b29c7 100644
--- a/drivers/s390/cio/vfio_ccw_private.h
+++ b/drivers/s390/cio/vfio_ccw_private.h
@@ -88,6 +88,7 @@ struct vfio_ccw_crw {
  * @req_trigger: eventfd ctx for signaling userspace to return device
  * @io_work: work for deferral process of I/O handling
  * @crw_work: work for deferral process of CRW handling
+ * @release_comp: synchronization helper for vfio device release
  */
 struct vfio_ccw_private {
 	struct vfio_device vdev;
@@ -113,6 +114,8 @@ struct vfio_ccw_private {
 	struct eventfd_ctx	*req_trigger;
 	struct work_struct	io_work;
 	struct work_struct	crw_work;
+
+	struct completion	release_comp;
 } __aligned(8);
 
 int vfio_ccw_sch_quiesce(struct subchannel *sch);
diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
index c9d982131265..957d9f286550 100644
--- a/drivers/vfio/vfio_main.c
+++ b/drivers/vfio/vfio_main.c
@@ -481,28 +481,13 @@ static struct vfio_device *vfio_group_get_device(struct vfio_group *group,
 /*
  * VFIO driver API
  */
-void vfio_init_group_dev(struct vfio_device *device, struct device *dev,
-			 const struct vfio_device_ops *ops)
-{
-	init_completion(&device->comp);
-	device->dev = dev;
-	device->ops = ops;
-}
-EXPORT_SYMBOL_GPL(vfio_init_group_dev);
-
-void vfio_uninit_group_dev(struct vfio_device *device)
-{
-	vfio_release_device_set(device);
-}
-EXPORT_SYMBOL_GPL(vfio_uninit_group_dev);
-
 /* Release helper called by vfio_put_device() */
 void vfio_device_release(struct kref *kref)
 {
 	struct vfio_device *device =
 			container_of(kref, struct vfio_device, kref);
 
-	vfio_uninit_group_dev(device);
+	vfio_release_device_set(device);
 
 	/*
 	 * kvfree() cannot be done here due to a life cycle mess in
@@ -560,7 +545,9 @@ int vfio_init_device(struct vfio_device *device, struct device *dev,
 {
 	int ret;
 
-	vfio_init_group_dev(device, dev, ops);
+	init_completion(&device->comp);
+	device->dev = dev;
+	device->ops = ops;
 
 	if (ops->init) {
 		ret = ops->init(device);
@@ -572,7 +559,7 @@ int vfio_init_device(struct vfio_device *device, struct device *dev,
 	return 0;
 
 out_uninit:
-	vfio_uninit_group_dev(device);
+	vfio_release_device_set(device);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(vfio_init_device);
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index e1e9e8352903..f03447c8774d 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -160,9 +160,6 @@ static inline void vfio_put_device(struct vfio_device *device)
 	kref_put(&device->kref, vfio_device_release);
 }
 
-void vfio_init_group_dev(struct vfio_device *device, struct device *dev,
-			 const struct vfio_device_ops *ops);
-void vfio_uninit_group_dev(struct vfio_device *device);
 int vfio_register_group_dev(struct vfio_device *device);
 int vfio_register_emulated_iommu_dev(struct vfio_device *device);
 void vfio_unregister_group_dev(struct vfio_device *device);
-- 
2.21.3

RE: [PATCH v2 13/15] vfio/ccw: Use the new device life cycle helpers

[Tian, Kevin]

ping @Eric Farman.

ccw is the only tricky player in this series. Please help take a look in case of
any oversight here.

> From: Tian, Kevin <kevin.tian@intel.com>
> Sent: Thursday, September 1, 2022 10:38 PM
> 
> ccw is the only exception which cannot use vfio_alloc_device() because
> its private device structure is designed to serve both mdev and parent.
> Life cycle of the parent is managed by css_driver so vfio_ccw_private
> must be allocated/freed in css_driver probe/remove path instead of
> conforming to vfio core life cycle for mdev.
> 
> Given that use a wait/completion scheme so the mdev remove path waits
> after vfio_put_device() until receiving a completion notification from
> @release. The completion indicates that all active references on
> vfio_device have been released.
> 
> After that point although free of vfio_ccw_private is delayed to
> css_driver it's at least guaranteed to have no parallel reference on
> released vfio device part from other code paths.
> 
> memset() in @probe is removed. vfio_device is either already cleared
> when probed for the first time or cleared in @release from last probe.
> 
> The right fix is to introduce separate structures for mdev and parent,
> but this won't happen in short term per prior discussions.
> 
> Remove vfio_init/uninit_group_dev() as no user now.
> 
> Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
> Signed-off-by: Kevin Tian <kevin.tian@intel.com>
> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
> ---
>  drivers/s390/cio/vfio_ccw_ops.c     | 52 +++++++++++++++++++++++++----
>  drivers/s390/cio/vfio_ccw_private.h |  3 ++
>  drivers/vfio/vfio_main.c            | 23 +++----------
>  include/linux/vfio.h                |  3 --
>  4 files changed, 53 insertions(+), 28 deletions(-)
> 
> diff --git a/drivers/s390/cio/vfio_ccw_ops.c
> b/drivers/s390/cio/vfio_ccw_ops.c
> index 4a806a2273b5..9f8486c0d3d3 100644
> --- a/drivers/s390/cio/vfio_ccw_ops.c
> +++ b/drivers/s390/cio/vfio_ccw_ops.c
> @@ -87,6 +87,15 @@ static struct attribute_group *mdev_type_groups[] = {
>  	NULL,
>  };
> 
> +static int vfio_ccw_mdev_init_dev(struct vfio_device *vdev)
> +{
> +	struct vfio_ccw_private *private =
> +		container_of(vdev, struct vfio_ccw_private, vdev);
> +
> +	init_completion(&private->release_comp);
> +	return 0;
> +}
> +
>  static int vfio_ccw_mdev_probe(struct mdev_device *mdev)
>  {
>  	struct vfio_ccw_private *private = dev_get_drvdata(mdev-
> >dev.parent);
> @@ -98,9 +107,9 @@ static int vfio_ccw_mdev_probe(struct mdev_device
> *mdev)
>  	if (atomic_dec_if_positive(&private->avail) < 0)
>  		return -EPERM;
> 
> -	memset(&private->vdev, 0, sizeof(private->vdev));
> -	vfio_init_group_dev(&private->vdev, &mdev->dev,
> -			    &vfio_ccw_dev_ops);
> +	ret = vfio_init_device(&private->vdev, &mdev->dev,
> &vfio_ccw_dev_ops);
> +	if (ret)
> +		return ret;
> 
>  	VFIO_CCW_MSG_EVENT(2, "sch %x.%x.%04x: create\n",
>  			   private->sch->schid.cssid,
> @@ -109,16 +118,33 @@ static int vfio_ccw_mdev_probe(struct
> mdev_device *mdev)
> 
>  	ret = vfio_register_emulated_iommu_dev(&private->vdev);
>  	if (ret)
> -		goto err_atomic;
> +		goto err_put_vdev;
>  	dev_set_drvdata(&mdev->dev, private);
>  	return 0;
> 
> -err_atomic:
> -	vfio_uninit_group_dev(&private->vdev);
> +err_put_vdev:
> +	vfio_put_device(&private->vdev);
>  	atomic_inc(&private->avail);
>  	return ret;
>  }
> 
> +static void vfio_ccw_mdev_release_dev(struct vfio_device *vdev)
> +{
> +	struct vfio_ccw_private *private =
> +		container_of(vdev, struct vfio_ccw_private, vdev);
> +
> +	/*
> +	 * We cannot free vfio_ccw_private here because it includes
> +	 * parent info which must be free'ed by css driver.
> +	 *
> +	 * Use a workaround by memset'ing the core device part and
> +	 * then notifying the remove path that all active references
> +	 * to this device have been released.
> +	 */
> +	memset(vdev, 0, sizeof(*vdev));
> +	complete(&private->release_comp);
> +}
> +
>  static void vfio_ccw_mdev_remove(struct mdev_device *mdev)
>  {
>  	struct vfio_ccw_private *private = dev_get_drvdata(mdev-
> >dev.parent);
> @@ -130,7 +156,17 @@ static void vfio_ccw_mdev_remove(struct
> mdev_device *mdev)
> 
>  	vfio_unregister_group_dev(&private->vdev);
> 
> -	vfio_uninit_group_dev(&private->vdev);
> +	vfio_put_device(&private->vdev);
> +	/*
> +	 * Wait for all active references on mdev are released so it
> +	 * is safe to defer kfree() to a later point.
> +	 *
> +	 * TODO: the clean fix is to split parent/mdev info from ccw
> +	 * private structure so each can be managed in its own life
> +	 * cycle.
> +	 */
> +	wait_for_completion(&private->release_comp);
> +
>  	atomic_inc(&private->avail);
>  }
> 
> @@ -592,6 +628,8 @@ static void vfio_ccw_mdev_request(struct vfio_device
> *vdev, unsigned int count)
>  }
> 
>  static const struct vfio_device_ops vfio_ccw_dev_ops = {
> +	.init = vfio_ccw_mdev_init_dev,
> +	.release = vfio_ccw_mdev_release_dev,
>  	.open_device = vfio_ccw_mdev_open_device,
>  	.close_device = vfio_ccw_mdev_close_device,
>  	.read = vfio_ccw_mdev_read,
> diff --git a/drivers/s390/cio/vfio_ccw_private.h
> b/drivers/s390/cio/vfio_ccw_private.h
> index cd24b7fada91..63d9202b29c7 100644
> --- a/drivers/s390/cio/vfio_ccw_private.h
> +++ b/drivers/s390/cio/vfio_ccw_private.h
> @@ -88,6 +88,7 @@ struct vfio_ccw_crw {
>   * @req_trigger: eventfd ctx for signaling userspace to return device
>   * @io_work: work for deferral process of I/O handling
>   * @crw_work: work for deferral process of CRW handling
> + * @release_comp: synchronization helper for vfio device release
>   */
>  struct vfio_ccw_private {
>  	struct vfio_device vdev;
> @@ -113,6 +114,8 @@ struct vfio_ccw_private {
>  	struct eventfd_ctx	*req_trigger;
>  	struct work_struct	io_work;
>  	struct work_struct	crw_work;
> +
> +	struct completion	release_comp;
>  } __aligned(8);
> 
>  int vfio_ccw_sch_quiesce(struct subchannel *sch);
> diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
> index c9d982131265..957d9f286550 100644
> --- a/drivers/vfio/vfio_main.c
> +++ b/drivers/vfio/vfio_main.c
> @@ -481,28 +481,13 @@ static struct vfio_device
> *vfio_group_get_device(struct vfio_group *group,
>  /*
>   * VFIO driver API
>   */
> -void vfio_init_group_dev(struct vfio_device *device, struct device *dev,
> -			 const struct vfio_device_ops *ops)
> -{
> -	init_completion(&device->comp);
> -	device->dev = dev;
> -	device->ops = ops;
> -}
> -EXPORT_SYMBOL_GPL(vfio_init_group_dev);
> -
> -void vfio_uninit_group_dev(struct vfio_device *device)
> -{
> -	vfio_release_device_set(device);
> -}
> -EXPORT_SYMBOL_GPL(vfio_uninit_group_dev);
> -
>  /* Release helper called by vfio_put_device() */
>  void vfio_device_release(struct kref *kref)
>  {
>  	struct vfio_device *device =
>  			container_of(kref, struct vfio_device, kref);
> 
> -	vfio_uninit_group_dev(device);
> +	vfio_release_device_set(device);
> 
>  	/*
>  	 * kvfree() cannot be done here due to a life cycle mess in
> @@ -560,7 +545,9 @@ int vfio_init_device(struct vfio_device *device, struct
> device *dev,
>  {
>  	int ret;
> 
> -	vfio_init_group_dev(device, dev, ops);
> +	init_completion(&device->comp);
> +	device->dev = dev;
> +	device->ops = ops;
> 
>  	if (ops->init) {
>  		ret = ops->init(device);
> @@ -572,7 +559,7 @@ int vfio_init_device(struct vfio_device *device, struct
> device *dev,
>  	return 0;
> 
>  out_uninit:
> -	vfio_uninit_group_dev(device);
> +	vfio_release_device_set(device);
>  	return ret;
>  }
>  EXPORT_SYMBOL_GPL(vfio_init_device);
> diff --git a/include/linux/vfio.h b/include/linux/vfio.h
> index e1e9e8352903..f03447c8774d 100644
> --- a/include/linux/vfio.h
> +++ b/include/linux/vfio.h
> @@ -160,9 +160,6 @@ static inline void vfio_put_device(struct vfio_device
> *device)
>  	kref_put(&device->kref, vfio_device_release);
>  }
> 
> -void vfio_init_group_dev(struct vfio_device *device, struct device *dev,
> -			 const struct vfio_device_ops *ops);
> -void vfio_uninit_group_dev(struct vfio_device *device);
>  int vfio_register_group_dev(struct vfio_device *device);
>  int vfio_register_emulated_iommu_dev(struct vfio_device *device);
>  void vfio_unregister_group_dev(struct vfio_device *device);
> --
> 2.21.3

Re: [PATCH v2 13/15] vfio/ccw: Use the new device life cycle helpers

[Eric Farman]

On Thu, 2022-09-08 at 07:19 +0000, Tian, Kevin wrote:
> ping @Eric Farman.
> 
> ccw is the only tricky player in this series. Please help take a look
> in case of
> any oversight here.

Apologies, I had started looking at v1 before I left on holiday, and
only returned today.

> 
> > From: Tian, Kevin <kevin.tian@intel.com>
> > Sent: Thursday, September 1, 2022 10:38 PM
> > 
> > ccw is the only exception which cannot use vfio_alloc_device()
> > because
> > its private device structure is designed to serve both mdev and
> > parent.
> > Life cycle of the parent is managed by css_driver so
> > vfio_ccw_private
> > must be allocated/freed in css_driver probe/remove path instead of
> > conforming to vfio core life cycle for mdev.
> > 
> > Given that use a wait/completion scheme so the mdev remove path
> > waits
> > after vfio_put_device() until receiving a completion notification
> > from
> > @release. The completion indicates that all active references on
> > vfio_device have been released.
> > 
> > After that point although free of vfio_ccw_private is delayed to
> > css_driver it's at least guaranteed to have no parallel reference
> > on
> > released vfio device part from other code paths.
> > 
> > memset() in @probe is removed. vfio_device is either already
> > cleared
> > when probed for the first time or cleared in @release from last
> > probe.
> > 
> > The right fix is to introduce separate structures for mdev and
> > parent,
> > but this won't happen in short term per prior discussions.

I did start looking at the above, while the mdev series is outstanding.
Will try to get back to that sooner rather than later, but for the
purposes of this series this patch looks/works fine to me.

Reviewed-by: Eric Farman <farman@linux.ibm.com>

> > 
> > Remove vfio_init/uninit_group_dev() as no user now.
> > 
> > Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
> > Signed-off-by: Kevin Tian <kevin.tian@intel.com>
> > Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
> > ---
> >  drivers/s390/cio/vfio_ccw_ops.c     | 52
> > +++++++++++++++++++++++++----
> >  drivers/s390/cio/vfio_ccw_private.h |  3 ++
> >  drivers/vfio/vfio_main.c            | 23 +++----------
> >  include/linux/vfio.h                |  3 --
> >  4 files changed, 53 insertions(+), 28 deletions(-)
> > 
> > diff --git a/drivers/s390/cio/vfio_ccw_ops.c
> > b/drivers/s390/cio/vfio_ccw_ops.c
> > index 4a806a2273b5..9f8486c0d3d3 100644
> > --- a/drivers/s390/cio/vfio_ccw_ops.c
> > +++ b/drivers/s390/cio/vfio_ccw_ops.c
> > @@ -87,6 +87,15 @@ static struct attribute_group
> > *mdev_type_groups[] = {
> >         NULL,
> >  };
> > 
> > +static int vfio_ccw_mdev_init_dev(struct vfio_device *vdev)
> > +{
> > +       struct vfio_ccw_private *private =
> > +               container_of(vdev, struct vfio_ccw_private, vdev);
> > +
> > +       init_completion(&private->release_comp);
> > +       return 0;
> > +}
> > +
> >  static int vfio_ccw_mdev_probe(struct mdev_device *mdev)
> >  {
> >         struct vfio_ccw_private *private = dev_get_drvdata(mdev-
> > > dev.parent);
> > @@ -98,9 +107,9 @@ static int vfio_ccw_mdev_probe(struct
> > mdev_device
> > *mdev)
> >         if (atomic_dec_if_positive(&private->avail) < 0)
> >                 return -EPERM;
> > 
> > -       memset(&private->vdev, 0, sizeof(private->vdev));
> > -       vfio_init_group_dev(&private->vdev, &mdev->dev,
> > -                           &vfio_ccw_dev_ops);
> > +       ret = vfio_init_device(&private->vdev, &mdev->dev,
> > &vfio_ccw_dev_ops);
> > +       if (ret)
> > +               return ret;
> > 
> >         VFIO_CCW_MSG_EVENT(2, "sch %x.%x.%04x: create\n",
> >                            private->sch->schid.cssid,
> > @@ -109,16 +118,33 @@ static int vfio_ccw_mdev_probe(struct
> > mdev_device *mdev)
> > 
> >         ret = vfio_register_emulated_iommu_dev(&private->vdev);
> >         if (ret)
> > -               goto err_atomic;
> > +               goto err_put_vdev;
> >         dev_set_drvdata(&mdev->dev, private);
> >         return 0;
> > 
> > -err_atomic:
> > -       vfio_uninit_group_dev(&private->vdev);
> > +err_put_vdev:
> > +       vfio_put_device(&private->vdev);
> >         atomic_inc(&private->avail);
> >         return ret;
> >  }
> > 
> > +static void vfio_ccw_mdev_release_dev(struct vfio_device *vdev)
> > +{
> > +       struct vfio_ccw_private *private =
> > +               container_of(vdev, struct vfio_ccw_private, vdev);
> > +
> > +       /*
> > +        * We cannot free vfio_ccw_private here because it includes
> > +        * parent info which must be free'ed by css driver.
> > +        *
> > +        * Use a workaround by memset'ing the core device part and
> > +        * then notifying the remove path that all active
> > references
> > +        * to this device have been released.
> > +        */
> > +       memset(vdev, 0, sizeof(*vdev));
> > +       complete(&private->release_comp);
> > +}
> > +
> >  static void vfio_ccw_mdev_remove(struct mdev_device *mdev)
> >  {
> >         struct vfio_ccw_private *private = dev_get_drvdata(mdev-
> > > dev.parent);
> > @@ -130,7 +156,17 @@ static void vfio_ccw_mdev_remove(struct
> > mdev_device *mdev)
> > 
> >         vfio_unregister_group_dev(&private->vdev);
> > 
> > -       vfio_uninit_group_dev(&private->vdev);
> > +       vfio_put_device(&private->vdev);
> > +       /*
> > +        * Wait for all active references on mdev are released so
> > it
> > +        * is safe to defer kfree() to a later point.
> > +        *
> > +        * TODO: the clean fix is to split parent/mdev info from
> > ccw
> > +        * private structure so each can be managed in its own life
> > +        * cycle.
> > +        */
> > +       wait_for_completion(&private->release_comp);
> > +
> >         atomic_inc(&private->avail);
> >  }
> > 
> > @@ -592,6 +628,8 @@ static void vfio_ccw_mdev_request(struct
> > vfio_device
> > *vdev, unsigned int count)
> >  }
> > 
> >  static const struct vfio_device_ops vfio_ccw_dev_ops = {
> > +       .init = vfio_ccw_mdev_init_dev,
> > +       .release = vfio_ccw_mdev_release_dev,
> >         .open_device = vfio_ccw_mdev_open_device,
> >         .close_device = vfio_ccw_mdev_close_device,
> >         .read = vfio_ccw_mdev_read,
> > diff --git a/drivers/s390/cio/vfio_ccw_private.h
> > b/drivers/s390/cio/vfio_ccw_private.h
> > index cd24b7fada91..63d9202b29c7 100644
> > --- a/drivers/s390/cio/vfio_ccw_private.h
> > +++ b/drivers/s390/cio/vfio_ccw_private.h
> > @@ -88,6 +88,7 @@ struct vfio_ccw_crw {
> >   * @req_trigger: eventfd ctx for signaling userspace to return
> > device
> >   * @io_work: work for deferral process of I/O handling
> >   * @crw_work: work for deferral process of CRW handling
> > + * @release_comp: synchronization helper for vfio device release
> >   */
> >  struct vfio_ccw_private {
> >         struct vfio_device vdev;
> > @@ -113,6 +114,8 @@ struct vfio_ccw_private {
> >         struct eventfd_ctx      *req_trigger;
> >         struct work_struct      io_work;
> >         struct work_struct      crw_work;
> > +
> > +       struct completion       release_comp;
> >  } __aligned(8);
> > 
> >  int vfio_ccw_sch_quiesce(struct subchannel *sch);
> > diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
> > index c9d982131265..957d9f286550 100644
> > --- a/drivers/vfio/vfio_main.c
> > +++ b/drivers/vfio/vfio_main.c
> > @@ -481,28 +481,13 @@ static struct vfio_device
> > *vfio_group_get_device(struct vfio_group *group,
> >  /*
> >   * VFIO driver API
> >   */
> > -void vfio_init_group_dev(struct vfio_device *device, struct device
> > *dev,
> > -                        const struct vfio_device_ops *ops)
> > -{
> > -       init_completion(&device->comp);
> > -       device->dev = dev;
> > -       device->ops = ops;
> > -}
> > -EXPORT_SYMBOL_GPL(vfio_init_group_dev);
> > -
> > -void vfio_uninit_group_dev(struct vfio_device *device)
> > -{
> > -       vfio_release_device_set(device);
> > -}
> > -EXPORT_SYMBOL_GPL(vfio_uninit_group_dev);
> > -
> >  /* Release helper called by vfio_put_device() */
> >  void vfio_device_release(struct kref *kref)
> >  {
> >         struct vfio_device *device =
> >                         container_of(kref, struct vfio_device,
> > kref);
> > 
> > -       vfio_uninit_group_dev(device);
> > +       vfio_release_device_set(device);
> > 
> >         /*
> >          * kvfree() cannot be done here due to a life cycle mess in
> > @@ -560,7 +545,9 @@ int vfio_init_device(struct vfio_device
> > *device, struct
> > device *dev,
> >  {
> >         int ret;
> > 
> > -       vfio_init_group_dev(device, dev, ops);
> > +       init_completion(&device->comp);
> > +       device->dev = dev;
> > +       device->ops = ops;
> > 
> >         if (ops->init) {
> >                 ret = ops->init(device);
> > @@ -572,7 +559,7 @@ int vfio_init_device(struct vfio_device
> > *device, struct
> > device *dev,
> >         return 0;
> > 
> >  out_uninit:
> > -       vfio_uninit_group_dev(device);
> > +       vfio_release_device_set(device);
> >         return ret;
> >  }
> >  EXPORT_SYMBOL_GPL(vfio_init_device);
> > diff --git a/include/linux/vfio.h b/include/linux/vfio.h
> > index e1e9e8352903..f03447c8774d 100644
> > --- a/include/linux/vfio.h
> > +++ b/include/linux/vfio.h
> > @@ -160,9 +160,6 @@ static inline void vfio_put_device(struct
> > vfio_device
> > *device)
> >         kref_put(&device->kref, vfio_device_release);
> >  }
> > 
> > -void vfio_init_group_dev(struct vfio_device *device, struct device
> > *dev,
> > -                        const struct vfio_device_ops *ops);
> > -void vfio_uninit_group_dev(struct vfio_device *device);
> >  int vfio_register_group_dev(struct vfio_device *device);
> >  int vfio_register_emulated_iommu_dev(struct vfio_device *device);
> >  void vfio_unregister_group_dev(struct vfio_device *device);
> > --
> > 2.21.3
> 

RE: [PATCH v2 13/15] vfio/ccw: Use the new device life cycle helpers

[Tian, Kevin]

> From: Eric Farman
> Sent: Friday, September 9, 2022 4:51 AM
> 
> On Thu, 2022-09-08 at 07:19 +0000, Tian, Kevin wrote:
> > ping @Eric Farman.
> >
> > ccw is the only tricky player in this series. Please help take a look
> > in case of
> > any oversight here.
> 
> Apologies, I had started looking at v1 before I left on holiday, and
> only returned today.
> 
> >
> > > From: Tian, Kevin <kevin.tian@intel.com>
> > > Sent: Thursday, September 1, 2022 10:38 PM
> > >
> > > ccw is the only exception which cannot use vfio_alloc_device()
> > > because
> > > its private device structure is designed to serve both mdev and
> > > parent.
> > > Life cycle of the parent is managed by css_driver so
> > > vfio_ccw_private
> > > must be allocated/freed in css_driver probe/remove path instead of
> > > conforming to vfio core life cycle for mdev.
> > >
> > > Given that use a wait/completion scheme so the mdev remove path
> > > waits
> > > after vfio_put_device() until receiving a completion notification
> > > from
> > > @release. The completion indicates that all active references on
> > > vfio_device have been released.
> > >
> > > After that point although free of vfio_ccw_private is delayed to
> > > css_driver it's at least guaranteed to have no parallel reference
> > > on
> > > released vfio device part from other code paths.
> > >
> > > memset() in @probe is removed. vfio_device is either already
> > > cleared
> > > when probed for the first time or cleared in @release from last
> > > probe.
> > >
> > > The right fix is to introduce separate structures for mdev and
> > > parent,
> > > but this won't happen in short term per prior discussions.
> 
> I did start looking at the above, while the mdev series is outstanding.
> Will try to get back to that sooner rather than later, but for the
> purposes of this series this patch looks/works fine to me.
> 
> Reviewed-by: Eric Farman <farman@linux.ibm.com>
> 

Thanks!

[PATCH v2 14/15] vfio: Rename vfio_device_put() and vfio_device_try_get()

[Kevin Tian]

With the addition of vfio_put_device() now the names become confusing.

vfio_put_device() is clear from object life cycle p.o.v given kref.

vfio_device_put()/vfio_device_try_get() are helpers for tracking
users on a registered device.

Now rename them:

 - vfio_device_put() -> vfio_device_put_registration()
 - vfio_device_try_get() -> vfio_device_try_get_registration()

Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
---
 drivers/vfio/vfio_main.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
index 957d9f286550..bfa675d314ab 100644
--- a/drivers/vfio/vfio_main.c
+++ b/drivers/vfio/vfio_main.c
@@ -451,13 +451,13 @@ static void vfio_group_get(struct vfio_group *group)
  * Device objects - create, release, get, put, search
  */
 /* Device reference always implies a group reference */
-static void vfio_device_put(struct vfio_device *device)
+static void vfio_device_put_registration(struct vfio_device *device)
 {
 	if (refcount_dec_and_test(&device->refcount))
 		complete(&device->comp);
 }
 
-static bool vfio_device_try_get(struct vfio_device *device)
+static bool vfio_device_try_get_registration(struct vfio_device *device)
 {
 	return refcount_inc_not_zero(&device->refcount);
 }
@@ -469,7 +469,8 @@ static struct vfio_device *vfio_group_get_device(struct vfio_group *group,
 
 	mutex_lock(&group->device_lock);
 	list_for_each_entry(device, &group->device_list, group_next) {
-		if (device->dev == dev && vfio_device_try_get(device)) {
+		if (device->dev == dev &&
+		    vfio_device_try_get_registration(device)) {
 			mutex_unlock(&group->device_lock);
 			return device;
 		}
@@ -671,7 +672,7 @@ static int __vfio_register_dev(struct vfio_device *device,
 	if (existing_device) {
 		dev_WARN(device->dev, "Device already exists on group %d\n",
 			 iommu_group_id(group->iommu_group));
-		vfio_device_put(existing_device);
+		vfio_device_put_registration(existing_device);
 		if (group->type == VFIO_NO_IOMMU ||
 		    group->type == VFIO_EMULATED_IOMMU)
 			iommu_group_remove_device(device->dev);
@@ -730,7 +731,7 @@ static struct vfio_device *vfio_device_get_from_name(struct vfio_group *group,
 			ret = !strcmp(dev_name(it->dev), buf);
 		}
 
-		if (ret && vfio_device_try_get(it)) {
+		if (ret && vfio_device_try_get_registration(it)) {
 			device = it;
 			break;
 		}
@@ -750,7 +751,7 @@ void vfio_unregister_group_dev(struct vfio_device *device)
 	bool interrupted = false;
 	long rc;
 
-	vfio_device_put(device);
+	vfio_device_put_registration(device);
 	rc = try_wait_for_completion(&device->comp);
 	while (rc <= 0) {
 		if (device->ops->request)
@@ -1286,7 +1287,7 @@ static int vfio_group_get_device_fd(struct vfio_group *group, char *buf)
 err_put_fdno:
 	put_unused_fd(fdno);
 err_put_device:
-	vfio_device_put(device);
+	vfio_device_put_registration(device);
 	return ret;
 }
 
@@ -1461,7 +1462,7 @@ static int vfio_device_fops_release(struct inode *inode, struct file *filep)
 
 	vfio_device_unassign_container(device);
 
-	vfio_device_put(device);
+	vfio_device_put_registration(device);
 
 	return 0;
 }
-- 
2.21.3

Re: [PATCH v2 14/15] vfio: Rename vfio_device_put() and vfio_device_try_get()

[Eric Auger]

On 9/1/22 16:37, Kevin Tian wrote:
> With the addition of vfio_put_device() now the names become confusing.
>
> vfio_put_device() is clear from object life cycle p.o.v given kref.
>
> vfio_device_put()/vfio_device_try_get() are helpers for tracking
> users on a registered device.
>
> Now rename them:
>
>  - vfio_device_put() -> vfio_device_put_registration()
>  - vfio_device_try_get() -> vfio_device_try_get_registration()
>
> Signed-off-by: Kevin Tian <kevin.tian@intel.com>
> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>

Eric
> ---
>  drivers/vfio/vfio_main.c | 17 +++++++++--------
>  1 file changed, 9 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
> index 957d9f286550..bfa675d314ab 100644
> --- a/drivers/vfio/vfio_main.c
> +++ b/drivers/vfio/vfio_main.c
> @@ -451,13 +451,13 @@ static void vfio_group_get(struct vfio_group *group)
>   * Device objects - create, release, get, put, search
>   */
>  /* Device reference always implies a group reference */
> -static void vfio_device_put(struct vfio_device *device)
> +static void vfio_device_put_registration(struct vfio_device *device)
>  {
>  	if (refcount_dec_and_test(&device->refcount))
>  		complete(&device->comp);
>  }
>  
> -static bool vfio_device_try_get(struct vfio_device *device)
> +static bool vfio_device_try_get_registration(struct vfio_device *device)
>  {
>  	return refcount_inc_not_zero(&device->refcount);
>  }
> @@ -469,7 +469,8 @@ static struct vfio_device *vfio_group_get_device(struct vfio_group *group,
>  
>  	mutex_lock(&group->device_lock);
>  	list_for_each_entry(device, &group->device_list, group_next) {
> -		if (device->dev == dev && vfio_device_try_get(device)) {
> +		if (device->dev == dev &&
> +		    vfio_device_try_get_registration(device)) {
>  			mutex_unlock(&group->device_lock);
>  			return device;
>  		}
> @@ -671,7 +672,7 @@ static int __vfio_register_dev(struct vfio_device *device,
>  	if (existing_device) {
>  		dev_WARN(device->dev, "Device already exists on group %d\n",
>  			 iommu_group_id(group->iommu_group));
> -		vfio_device_put(existing_device);
> +		vfio_device_put_registration(existing_device);
>  		if (group->type == VFIO_NO_IOMMU ||
>  		    group->type == VFIO_EMULATED_IOMMU)
>  			iommu_group_remove_device(device->dev);
> @@ -730,7 +731,7 @@ static struct vfio_device *vfio_device_get_from_name(struct vfio_group *group,
>  			ret = !strcmp(dev_name(it->dev), buf);
>  		}
>  
> -		if (ret && vfio_device_try_get(it)) {
> +		if (ret && vfio_device_try_get_registration(it)) {
>  			device = it;
>  			break;
>  		}
> @@ -750,7 +751,7 @@ void vfio_unregister_group_dev(struct vfio_device *device)
>  	bool interrupted = false;
>  	long rc;
>  
> -	vfio_device_put(device);
> +	vfio_device_put_registration(device);
>  	rc = try_wait_for_completion(&device->comp);
>  	while (rc <= 0) {
>  		if (device->ops->request)
> @@ -1286,7 +1287,7 @@ static int vfio_group_get_device_fd(struct vfio_group *group, char *buf)
>  err_put_fdno:
>  	put_unused_fd(fdno);
>  err_put_device:
> -	vfio_device_put(device);
> +	vfio_device_put_registration(device);
>  	return ret;
>  }
>  
> @@ -1461,7 +1462,7 @@ static int vfio_device_fops_release(struct inode *inode, struct file *filep)
>  
>  	vfio_device_unassign_container(device);
>  
> -	vfio_device_put(device);
> +	vfio_device_put_registration(device);
>  
>  	return 0;
>  }

[PATCH v2 15/15] vfio: Add struct device to vfio_device

[Kevin Tian]

From: Yi Liu <yi.l.liu@intel.com>

and replace kref. With it a 'vfio-dev/vfioX' node is created under the
sysfs path of the parent, indicating the device is bound to a vfio
driver, e.g.:

/sys/devices/pci0000\:6f/0000\:6f\:01.0/vfio-dev/vfio0

It is also a preparatory step toward adding cdev for supporting future
device-oriented uAPI.

Add Documentation/ABI/testing/sysfs-devices-vfio-dev.

Also take this chance to rename chardev 'vfio' to 'vfio-group' in
/proc/devices.

Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
---
 .../ABI/testing/sysfs-devices-vfio-dev        |  8 +++
 drivers/vfio/vfio_main.c                      | 67 +++++++++++++++----
 include/linux/vfio.h                          |  6 +-
 3 files changed, 66 insertions(+), 15 deletions(-)
 create mode 100644 Documentation/ABI/testing/sysfs-devices-vfio-dev

diff --git a/Documentation/ABI/testing/sysfs-devices-vfio-dev b/Documentation/ABI/testing/sysfs-devices-vfio-dev
new file mode 100644
index 000000000000..e21424fd9666
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-devices-vfio-dev
@@ -0,0 +1,8 @@
+What:		 /sys/.../<device>/vfio-dev/vfioX/
+Date:		 September 2022
+Contact:	 Yi Liu <yi.l.liu@intel.com>
+Description:
+		 This directory is created when the device is bound to a
+		 vfio driver. The layout under this directory matches what
+		 exists for a standard 'struct device'. 'X' is a unique
+		 index marking this device in vfio.
diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
index bfa675d314ab..141f55c3faf5 100644
--- a/drivers/vfio/vfio_main.c
+++ b/drivers/vfio/vfio_main.c
@@ -46,6 +46,8 @@ static struct vfio {
 	struct mutex			group_lock; /* locks group_list */
 	struct ida			group_ida;
 	dev_t				group_devt;
+	struct class			*device_class;
+	struct ida			device_ida;
 } vfio;
 
 struct vfio_iommu_driver {
@@ -483,12 +485,13 @@ static struct vfio_device *vfio_group_get_device(struct vfio_group *group,
  * VFIO driver API
  */
 /* Release helper called by vfio_put_device() */
-void vfio_device_release(struct kref *kref)
+static void vfio_device_release(struct device *dev)
 {
 	struct vfio_device *device =
-			container_of(kref, struct vfio_device, kref);
+			container_of(dev, struct vfio_device, device);
 
 	vfio_release_device_set(device);
+	ida_free(&vfio.device_ida, device->index);
 
 	/*
 	 * kvfree() cannot be done here due to a life cycle mess in
@@ -498,7 +501,6 @@ void vfio_device_release(struct kref *kref)
 	 */
 	device->ops->release(device);
 }
-EXPORT_SYMBOL_GPL(vfio_device_release);
 
 /*
  * Alloc and initialize vfio_device so it can be registered to vfio
@@ -546,6 +548,13 @@ int vfio_init_device(struct vfio_device *device, struct device *dev,
 {
 	int ret;
 
+	ret = ida_alloc_max(&vfio.device_ida, MINORMASK, GFP_KERNEL);
+	if (ret < 0) {
+		dev_dbg(dev, "Error to alloc index\n");
+		return ret;
+	}
+
+	device->index = ret;
 	init_completion(&device->comp);
 	device->dev = dev;
 	device->ops = ops;
@@ -556,11 +565,15 @@ int vfio_init_device(struct vfio_device *device, struct device *dev,
 			goto out_uninit;
 	}
 
-	kref_init(&device->kref);
+	device_initialize(&device->device);
+	device->device.release = vfio_device_release;
+	device->device.class = vfio.device_class;
+	device->device.parent = device->dev;
 	return 0;
 
 out_uninit:
 	vfio_release_device_set(device);
+	ida_free(&vfio.device_ida, device->index);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(vfio_init_device);
@@ -657,6 +670,7 @@ static int __vfio_register_dev(struct vfio_device *device,
 		struct vfio_group *group)
 {
 	struct vfio_device *existing_device;
+	int ret;
 
 	if (IS_ERR(group))
 		return PTR_ERR(group);
@@ -673,16 +687,21 @@ static int __vfio_register_dev(struct vfio_device *device,
 		dev_WARN(device->dev, "Device already exists on group %d\n",
 			 iommu_group_id(group->iommu_group));
 		vfio_device_put_registration(existing_device);
-		if (group->type == VFIO_NO_IOMMU ||
-		    group->type == VFIO_EMULATED_IOMMU)
-			iommu_group_remove_device(device->dev);
-		vfio_group_put(group);
-		return -EBUSY;
+		ret = -EBUSY;
+		goto err_out;
 	}
 
 	/* Our reference on group is moved to the device */
 	device->group = group;
 
+	ret = dev_set_name(&device->device, "vfio%d", device->index);
+	if (ret)
+		goto err_out;
+
+	ret = device_add(&device->device);
+	if (ret)
+		goto err_out;
+
 	/* Refcounting can't start until the driver calls register */
 	refcount_set(&device->refcount, 1);
 
@@ -692,6 +711,12 @@ static int __vfio_register_dev(struct vfio_device *device,
 	mutex_unlock(&group->device_lock);
 
 	return 0;
+err_out:
+	if (group->type == VFIO_NO_IOMMU ||
+	    group->type == VFIO_EMULATED_IOMMU)
+		iommu_group_remove_device(device->dev);
+	vfio_group_put(group);
+	return ret;
 }
 
 int vfio_register_group_dev(struct vfio_device *device)
@@ -779,6 +804,9 @@ void vfio_unregister_group_dev(struct vfio_device *device)
 	group->dev_counter--;
 	mutex_unlock(&group->device_lock);
 
+	/* Balances device_add in register path */
+	device_del(&device->device);
+
 	if (group->type == VFIO_NO_IOMMU || group->type == VFIO_EMULATED_IOMMU)
 		iommu_group_remove_device(device->dev);
 
@@ -2145,6 +2173,7 @@ static int __init vfio_init(void)
 	int ret;
 
 	ida_init(&vfio.group_ida);
+	ida_init(&vfio.device_ida);
 	mutex_init(&vfio.group_lock);
 	mutex_init(&vfio.iommu_drivers_lock);
 	INIT_LIST_HEAD(&vfio.group_list);
@@ -2160,12 +2189,20 @@ static int __init vfio_init(void)
 	vfio.class = class_create(THIS_MODULE, "vfio");
 	if (IS_ERR(vfio.class)) {
 		ret = PTR_ERR(vfio.class);
-		goto err_class;
+		goto err_group_class;
 	}
 
 	vfio.class->devnode = vfio_devnode;
 
-	ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1, "vfio");
+	/* /sys/class/vfio-dev/vfioX */
+	vfio.device_class = class_create(THIS_MODULE, "vfio-dev");
+	if (IS_ERR(vfio.device_class)) {
+		ret = PTR_ERR(vfio.device_class);
+		goto err_dev_class;
+	}
+
+	ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1,
+				  "vfio-group");
 	if (ret)
 		goto err_alloc_chrdev;
 
@@ -2181,9 +2218,12 @@ static int __init vfio_init(void)
 err_driver_register:
 	unregister_chrdev_region(vfio.group_devt, MINORMASK + 1);
 err_alloc_chrdev:
+	class_destroy(vfio.device_class);
+	vfio.device_class = NULL;
+err_dev_class:
 	class_destroy(vfio.class);
 	vfio.class = NULL;
-err_class:
+err_group_class:
 	misc_deregister(&vfio_dev);
 	return ret;
 }
@@ -2195,8 +2235,11 @@ static void __exit vfio_cleanup(void)
 #ifdef CONFIG_VFIO_NOIOMMU
 	vfio_unregister_iommu_driver(&vfio_noiommu_ops);
 #endif
+	ida_destroy(&vfio.device_ida);
 	ida_destroy(&vfio.group_ida);
 	unregister_chrdev_region(vfio.group_devt, MINORMASK + 1);
+	class_destroy(vfio.device_class);
+	vfio.device_class = NULL;
 	class_destroy(vfio.class);
 	vfio.class = NULL;
 	misc_deregister(&vfio_dev);
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index f03447c8774d..5c13f74da1bb 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -45,7 +45,8 @@ struct vfio_device {
 	struct kvm *kvm;
 
 	/* Members below here are private, not for driver use */
-	struct kref kref;	/* object life cycle */
+	unsigned int index;
+	struct device device;	/* device.kref covers object life circle */
 	refcount_t refcount;	/* user count on registered device*/
 	unsigned int open_count;
 	struct completion comp;
@@ -154,10 +155,9 @@ struct vfio_device *_vfio_alloc_device(size_t size, struct device *dev,
 int vfio_init_device(struct vfio_device *device, struct device *dev,
 		     const struct vfio_device_ops *ops);
 void vfio_free_device(struct vfio_device *device);
-void vfio_device_release(struct kref *kref);
 static inline void vfio_put_device(struct vfio_device *device)
 {
-	kref_put(&device->kref, vfio_device_release);
+	put_device(&device->device);
 }
 
 int vfio_register_group_dev(struct vfio_device *device);
-- 
2.21.3

RE: [PATCH v2 15/15] vfio: Add struct device to vfio_device

[Tian, Kevin]

> From: Tian, Kevin <kevin.tian@intel.com>
> Sent: Thursday, September 1, 2022 10:38 PM
> 
> diff --git a/Documentation/ABI/testing/sysfs-devices-vfio-dev
> b/Documentation/ABI/testing/sysfs-devices-vfio-dev
> new file mode 100644
> index 000000000000..e21424fd9666
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-devices-vfio-dev
> @@ -0,0 +1,8 @@
> +What:		 /sys/.../<device>/vfio-dev/vfioX/
> +Date:		 September 2022
> +Contact:	 Yi Liu <yi.l.liu@intel.com>
> +Description:
> +		 This directory is created when the device is bound to a
> +		 vfio driver. The layout under this directory matches what
> +		 exists for a standard 'struct device'. 'X' is a unique
> +		 index marking this device in vfio.

This missed an update to MAINTAINER file:

diff --git a/MAINTAINERS b/MAINTAINERS
index 589517372408..3fc8c599f4f2 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -21310,6 +21310,7 @@ R:      Cornelia Huck <cohuck@redhat.com>
 L:	kvm@vger.kernel.org
 S:	Maintained
 T:	git git://github.com/awilliam/linux-vfio.git
+F:	Documentation/ABI/testing/sysfs-devices-vfio-dev
 F:	Documentation/driver-api/vfio.rst
 F:	drivers/vfio/
 F:	include/linux/vfio.h

Alex, I sent a wrong version w/o fixing two checkpatch warnings (this
and the one in patch12). Please let me know whether you want me to
resend.

Thanks
Kevin

Re: [PATCH v2 15/15] vfio: Add struct device to vfio_device

[Eric Auger]

Hi Kevin,

On 9/1/22 16:37, Kevin Tian wrote:
> From: Yi Liu <yi.l.liu@intel.com>
>
> and replace kref. With it a 'vfio-dev/vfioX' node is created under the
> sysfs path of the parent, indicating the device is bound to a vfio
> driver, e.g.:
>
> /sys/devices/pci0000\:6f/0000\:6f\:01.0/vfio-dev/vfio0
>
> It is also a preparatory step toward adding cdev for supporting future
> device-oriented uAPI.
>
> Add Documentation/ABI/testing/sysfs-devices-vfio-dev.
>
> Also take this chance to rename chardev 'vfio' to 'vfio-group' in
> /proc/devices.
>
> Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
> Signed-off-by: Yi Liu <yi.l.liu@intel.com>
> Signed-off-by: Kevin Tian <kevin.tian@intel.com>
> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
> ---
>  .../ABI/testing/sysfs-devices-vfio-dev        |  8 +++
>  drivers/vfio/vfio_main.c                      | 67 +++++++++++++++----
>  include/linux/vfio.h                          |  6 +-
>  3 files changed, 66 insertions(+), 15 deletions(-)
>  create mode 100644 Documentation/ABI/testing/sysfs-devices-vfio-dev
>
> diff --git a/Documentation/ABI/testing/sysfs-devices-vfio-dev b/Documentation/ABI/testing/sysfs-devices-vfio-dev
> new file mode 100644
> index 000000000000..e21424fd9666
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-devices-vfio-dev
> @@ -0,0 +1,8 @@
> +What:		 /sys/.../<device>/vfio-dev/vfioX/
> +Date:		 September 2022
> +Contact:	 Yi Liu <yi.l.liu@intel.com>
> +Description:
> +		 This directory is created when the device is bound to a
> +		 vfio driver. The layout under this directory matches what
> +		 exists for a standard 'struct device'. 'X' is a unique
> +		 index marking this device in vfio.
> diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
> index bfa675d314ab..141f55c3faf5 100644
> --- a/drivers/vfio/vfio_main.c
> +++ b/drivers/vfio/vfio_main.c
> @@ -46,6 +46,8 @@ static struct vfio {
>  	struct mutex			group_lock; /* locks group_list */
>  	struct ida			group_ida;
>  	dev_t				group_devt;
> +	struct class			*device_class;
> +	struct ida			device_ida;
>  } vfio;
>  
>  struct vfio_iommu_driver {
> @@ -483,12 +485,13 @@ static struct vfio_device *vfio_group_get_device(struct vfio_group *group,
>   * VFIO driver API
>   */
>  /* Release helper called by vfio_put_device() */
> -void vfio_device_release(struct kref *kref)
> +static void vfio_device_release(struct device *dev)
>  {
>  	struct vfio_device *device =
> -			container_of(kref, struct vfio_device, kref);
> +			container_of(dev, struct vfio_device, device);
>  
>  	vfio_release_device_set(device);
> +	ida_free(&vfio.device_ida, device->index);
>  
>  	/*
>  	 * kvfree() cannot be done here due to a life cycle mess in
> @@ -498,7 +501,6 @@ void vfio_device_release(struct kref *kref)
>  	 */
>  	device->ops->release(device);
>  }
> -EXPORT_SYMBOL_GPL(vfio_device_release);
>  
>  /*
>   * Alloc and initialize vfio_device so it can be registered to vfio
> @@ -546,6 +548,13 @@ int vfio_init_device(struct vfio_device *device, struct device *dev,
>  {
>  	int ret;
>  
> +	ret = ida_alloc_max(&vfio.device_ida, MINORMASK, GFP_KERNEL);
> +	if (ret < 0) {
> +		dev_dbg(dev, "Error to alloc index\n");
> +		return ret;
> +	}
> +
> +	device->index = ret;
>  	init_completion(&device->comp);
>  	device->dev = dev;
>  	device->ops = ops;
> @@ -556,11 +565,15 @@ int vfio_init_device(struct vfio_device *device, struct device *dev,
>  			goto out_uninit;
>  	}
>  
> -	kref_init(&device->kref);
> +	device_initialize(&device->device);
> +	device->device.release = vfio_device_release;
> +	device->device.class = vfio.device_class;
> +	device->device.parent = device->dev;
>  	return 0;
>  
>  out_uninit:
>  	vfio_release_device_set(device);
> +	ida_free(&vfio.device_ida, device->index);
>  	return ret;
>  }
>  EXPORT_SYMBOL_GPL(vfio_init_device);
> @@ -657,6 +670,7 @@ static int __vfio_register_dev(struct vfio_device *device,
>  		struct vfio_group *group)
>  {
>  	struct vfio_device *existing_device;
> +	int ret;
>  
>  	if (IS_ERR(group))
>  		return PTR_ERR(group);
> @@ -673,16 +687,21 @@ static int __vfio_register_dev(struct vfio_device *device,
>  		dev_WARN(device->dev, "Device already exists on group %d\n",
>  			 iommu_group_id(group->iommu_group));
>  		vfio_device_put_registration(existing_device);
> -		if (group->type == VFIO_NO_IOMMU ||
> -		    group->type == VFIO_EMULATED_IOMMU)
> -			iommu_group_remove_device(device->dev);
> -		vfio_group_put(group);
> -		return -EBUSY;
> +		ret = -EBUSY;
> +		goto err_out;
>  	}
>  
>  	/* Our reference on group is moved to the device */
>  	device->group = group;
>  
> +	ret = dev_set_name(&device->device, "vfio%d", device->index);
> +	if (ret)
> +		goto err_out;
> +
> +	ret = device_add(&device->device);
> +	if (ret)
> +		goto err_out;
> +
>  	/* Refcounting can't start until the driver calls register */
>  	refcount_set(&device->refcount, 1);
>  
> @@ -692,6 +711,12 @@ static int __vfio_register_dev(struct vfio_device *device,
>  	mutex_unlock(&group->device_lock);
>  
>  	return 0;
> +err_out:
> +	if (group->type == VFIO_NO_IOMMU ||
> +	    group->type == VFIO_EMULATED_IOMMU)
> +		iommu_group_remove_device(device->dev);
> +	vfio_group_put(group);
> +	return ret;
>  }
>  
>  int vfio_register_group_dev(struct vfio_device *device)
> @@ -779,6 +804,9 @@ void vfio_unregister_group_dev(struct vfio_device *device)
>  	group->dev_counter--;
>  	mutex_unlock(&group->device_lock);
>  
> +	/* Balances device_add in register path */
> +	device_del(&device->device);
> +
>  	if (group->type == VFIO_NO_IOMMU || group->type == VFIO_EMULATED_IOMMU)
>  		iommu_group_remove_device(device->dev);
>  
> @@ -2145,6 +2173,7 @@ static int __init vfio_init(void)
>  	int ret;
>  
>  	ida_init(&vfio.group_ida);
> +	ida_init(&vfio.device_ida);
>  	mutex_init(&vfio.group_lock);
>  	mutex_init(&vfio.iommu_drivers_lock);
>  	INIT_LIST_HEAD(&vfio.group_list);
> @@ -2160,12 +2189,20 @@ static int __init vfio_init(void)
>  	vfio.class = class_create(THIS_MODULE, "vfio");
>  	if (IS_ERR(vfio.class)) {
>  		ret = PTR_ERR(vfio.class);
> -		goto err_class;
> +		goto err_group_class;
>  	}
>  
>  	vfio.class->devnode = vfio_devnode;
>  
> -	ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1, "vfio");
> +	/* /sys/class/vfio-dev/vfioX */
> +	vfio.device_class = class_create(THIS_MODULE, "vfio-dev");
> +	if (IS_ERR(vfio.device_class)) {
> +		ret = PTR_ERR(vfio.device_class);
> +		goto err_dev_class;
> +	}
> +
> +	ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1,
> +				  "vfio-group");
>  	if (ret)
>  		goto err_alloc_chrdev;
>  
> @@ -2181,9 +2218,12 @@ static int __init vfio_init(void)
>  err_driver_register:
>  	unregister_chrdev_region(vfio.group_devt, MINORMASK + 1);
>  err_alloc_chrdev:
> +	class_destroy(vfio.device_class);
> +	vfio.device_class = NULL;
> +err_dev_class:
>  	class_destroy(vfio.class);
>  	vfio.class = NULL;
> -err_class:
> +err_group_class:
>  	misc_deregister(&vfio_dev);
>  	return ret;
>  }
> @@ -2195,8 +2235,11 @@ static void __exit vfio_cleanup(void)
>  #ifdef CONFIG_VFIO_NOIOMMU
>  	vfio_unregister_iommu_driver(&vfio_noiommu_ops);
>  #endif
> +	ida_destroy(&vfio.device_ida);
>  	ida_destroy(&vfio.group_ida);
>  	unregister_chrdev_region(vfio.group_devt, MINORMASK + 1);
> +	class_destroy(vfio.device_class);
> +	vfio.device_class = NULL;
>  	class_destroy(vfio.class);
>  	vfio.class = NULL;
>  	misc_deregister(&vfio_dev);
> diff --git a/include/linux/vfio.h b/include/linux/vfio.h
> index f03447c8774d..5c13f74da1bb 100644
> --- a/include/linux/vfio.h
> +++ b/include/linux/vfio.h
> @@ -45,7 +45,8 @@ struct vfio_device {
>  	struct kvm *kvm;
>  
>  	/* Members below here are private, not for driver use */
> -	struct kref kref;	/* object life cycle */
> +	unsigned int index;
> +	struct device device;	/* device.kref covers object life circle */
>  	refcount_t refcount;	/* user count on registered device*/
>  	unsigned int open_count;
>  	struct completion comp;
I am not totally clear about remaining 'struct device *dev;' in
vfio_device struct. I see it used in some places. Is it supposed to
disappear at some point?
> @@ -154,10 +155,9 @@ struct vfio_device *_vfio_alloc_device(size_t size, struct device *dev,
>  int vfio_init_device(struct vfio_device *device, struct device *dev,
>  		     const struct vfio_device_ops *ops);
>  void vfio_free_device(struct vfio_device *device);
> -void vfio_device_release(struct kref *kref);
>  static inline void vfio_put_device(struct vfio_device *device)
>  {
> -	kref_put(&device->kref, vfio_device_release);
> +	put_device(&device->device);
>  }
>  
>  int vfio_register_group_dev(struct vfio_device *device);

Thanks

Eric

Re: [PATCH v2 15/15] vfio: Add struct device to vfio_device

[Yi Liu]

On 2022/9/8 17:06, Eric Auger wrote:
> Hi Kevin,
> 
> On 9/1/22 16:37, Kevin Tian wrote:
>> From: Yi Liu <yi.l.liu@intel.com>
>>
>> and replace kref. With it a 'vfio-dev/vfioX' node is created under the
>> sysfs path of the parent, indicating the device is bound to a vfio
>> driver, e.g.:
>>
>> /sys/devices/pci0000\:6f/0000\:6f\:01.0/vfio-dev/vfio0
>>
>> It is also a preparatory step toward adding cdev for supporting future
>> device-oriented uAPI.
>>
>> Add Documentation/ABI/testing/sysfs-devices-vfio-dev.
>>
>> Also take this chance to rename chardev 'vfio' to 'vfio-group' in
>> /proc/devices.
>>
>> Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
>> Signed-off-by: Yi Liu <yi.l.liu@intel.com>
>> Signed-off-by: Kevin Tian <kevin.tian@intel.com>
>> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
>> ---
>>   .../ABI/testing/sysfs-devices-vfio-dev        |  8 +++
>>   drivers/vfio/vfio_main.c                      | 67 +++++++++++++++----
>>   include/linux/vfio.h                          |  6 +-
>>   3 files changed, 66 insertions(+), 15 deletions(-)
>>   create mode 100644 Documentation/ABI/testing/sysfs-devices-vfio-dev
>>
>> diff --git a/Documentation/ABI/testing/sysfs-devices-vfio-dev b/Documentation/ABI/testing/sysfs-devices-vfio-dev
>> new file mode 100644
>> index 000000000000..e21424fd9666
>> --- /dev/null
>> +++ b/Documentation/ABI/testing/sysfs-devices-vfio-dev
>> @@ -0,0 +1,8 @@
>> +What:		 /sys/.../<device>/vfio-dev/vfioX/
>> +Date:		 September 2022
>> +Contact:	 Yi Liu <yi.l.liu@intel.com>
>> +Description:
>> +		 This directory is created when the device is bound to a
>> +		 vfio driver. The layout under this directory matches what
>> +		 exists for a standard 'struct device'. 'X' is a unique
>> +		 index marking this device in vfio.
>> diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
>> index bfa675d314ab..141f55c3faf5 100644
>> --- a/drivers/vfio/vfio_main.c
>> +++ b/drivers/vfio/vfio_main.c
>> @@ -46,6 +46,8 @@ static struct vfio {
>>   	struct mutex			group_lock; /* locks group_list */
>>   	struct ida			group_ida;
>>   	dev_t				group_devt;
>> +	struct class			*device_class;
>> +	struct ida			device_ida;
>>   } vfio;
>>   
>>   struct vfio_iommu_driver {
>> @@ -483,12 +485,13 @@ static struct vfio_device *vfio_group_get_device(struct vfio_group *group,
>>    * VFIO driver API
>>    */
>>   /* Release helper called by vfio_put_device() */
>> -void vfio_device_release(struct kref *kref)
>> +static void vfio_device_release(struct device *dev)
>>   {
>>   	struct vfio_device *device =
>> -			container_of(kref, struct vfio_device, kref);
>> +			container_of(dev, struct vfio_device, device);
>>   
>>   	vfio_release_device_set(device);
>> +	ida_free(&vfio.device_ida, device->index);
>>   
>>   	/*
>>   	 * kvfree() cannot be done here due to a life cycle mess in
>> @@ -498,7 +501,6 @@ void vfio_device_release(struct kref *kref)
>>   	 */
>>   	device->ops->release(device);
>>   }
>> -EXPORT_SYMBOL_GPL(vfio_device_release);
>>   
>>   /*
>>    * Alloc and initialize vfio_device so it can be registered to vfio
>> @@ -546,6 +548,13 @@ int vfio_init_device(struct vfio_device *device, struct device *dev,
>>   {
>>   	int ret;
>>   
>> +	ret = ida_alloc_max(&vfio.device_ida, MINORMASK, GFP_KERNEL);
>> +	if (ret < 0) {
>> +		dev_dbg(dev, "Error to alloc index\n");
>> +		return ret;
>> +	}
>> +
>> +	device->index = ret;
>>   	init_completion(&device->comp);
>>   	device->dev = dev;
>>   	device->ops = ops;
>> @@ -556,11 +565,15 @@ int vfio_init_device(struct vfio_device *device, struct device *dev,
>>   			goto out_uninit;
>>   	}
>>   
>> -	kref_init(&device->kref);
>> +	device_initialize(&device->device);
>> +	device->device.release = vfio_device_release;
>> +	device->device.class = vfio.device_class;
>> +	device->device.parent = device->dev;
>>   	return 0;
>>   
>>   out_uninit:
>>   	vfio_release_device_set(device);
>> +	ida_free(&vfio.device_ida, device->index);
>>   	return ret;
>>   }
>>   EXPORT_SYMBOL_GPL(vfio_init_device);
>> @@ -657,6 +670,7 @@ static int __vfio_register_dev(struct vfio_device *device,
>>   		struct vfio_group *group)
>>   {
>>   	struct vfio_device *existing_device;
>> +	int ret;
>>   
>>   	if (IS_ERR(group))
>>   		return PTR_ERR(group);
>> @@ -673,16 +687,21 @@ static int __vfio_register_dev(struct vfio_device *device,
>>   		dev_WARN(device->dev, "Device already exists on group %d\n",
>>   			 iommu_group_id(group->iommu_group));
>>   		vfio_device_put_registration(existing_device);
>> -		if (group->type == VFIO_NO_IOMMU ||
>> -		    group->type == VFIO_EMULATED_IOMMU)
>> -			iommu_group_remove_device(device->dev);
>> -		vfio_group_put(group);
>> -		return -EBUSY;
>> +		ret = -EBUSY;
>> +		goto err_out;
>>   	}
>>   
>>   	/* Our reference on group is moved to the device */
>>   	device->group = group;
>>   
>> +	ret = dev_set_name(&device->device, "vfio%d", device->index);
>> +	if (ret)
>> +		goto err_out;
>> +
>> +	ret = device_add(&device->device);
>> +	if (ret)
>> +		goto err_out;
>> +
>>   	/* Refcounting can't start until the driver calls register */
>>   	refcount_set(&device->refcount, 1);
>>   
>> @@ -692,6 +711,12 @@ static int __vfio_register_dev(struct vfio_device *device,
>>   	mutex_unlock(&group->device_lock);
>>   
>>   	return 0;
>> +err_out:
>> +	if (group->type == VFIO_NO_IOMMU ||
>> +	    group->type == VFIO_EMULATED_IOMMU)
>> +		iommu_group_remove_device(device->dev);
>> +	vfio_group_put(group);
>> +	return ret;
>>   }
>>   
>>   int vfio_register_group_dev(struct vfio_device *device)
>> @@ -779,6 +804,9 @@ void vfio_unregister_group_dev(struct vfio_device *device)
>>   	group->dev_counter--;
>>   	mutex_unlock(&group->device_lock);
>>   
>> +	/* Balances device_add in register path */
>> +	device_del(&device->device);
>> +
>>   	if (group->type == VFIO_NO_IOMMU || group->type == VFIO_EMULATED_IOMMU)
>>   		iommu_group_remove_device(device->dev);
>>   
>> @@ -2145,6 +2173,7 @@ static int __init vfio_init(void)
>>   	int ret;
>>   
>>   	ida_init(&vfio.group_ida);
>> +	ida_init(&vfio.device_ida);
>>   	mutex_init(&vfio.group_lock);
>>   	mutex_init(&vfio.iommu_drivers_lock);
>>   	INIT_LIST_HEAD(&vfio.group_list);
>> @@ -2160,12 +2189,20 @@ static int __init vfio_init(void)
>>   	vfio.class = class_create(THIS_MODULE, "vfio");
>>   	if (IS_ERR(vfio.class)) {
>>   		ret = PTR_ERR(vfio.class);
>> -		goto err_class;
>> +		goto err_group_class;
>>   	}
>>   
>>   	vfio.class->devnode = vfio_devnode;
>>   
>> -	ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1, "vfio");
>> +	/* /sys/class/vfio-dev/vfioX */
>> +	vfio.device_class = class_create(THIS_MODULE, "vfio-dev");
>> +	if (IS_ERR(vfio.device_class)) {
>> +		ret = PTR_ERR(vfio.device_class);
>> +		goto err_dev_class;
>> +	}
>> +
>> +	ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1,
>> +				  "vfio-group");
>>   	if (ret)
>>   		goto err_alloc_chrdev;
>>   
>> @@ -2181,9 +2218,12 @@ static int __init vfio_init(void)
>>   err_driver_register:
>>   	unregister_chrdev_region(vfio.group_devt, MINORMASK + 1);
>>   err_alloc_chrdev:
>> +	class_destroy(vfio.device_class);
>> +	vfio.device_class = NULL;
>> +err_dev_class:
>>   	class_destroy(vfio.class);
>>   	vfio.class = NULL;
>> -err_class:
>> +err_group_class:
>>   	misc_deregister(&vfio_dev);
>>   	return ret;
>>   }
>> @@ -2195,8 +2235,11 @@ static void __exit vfio_cleanup(void)
>>   #ifdef CONFIG_VFIO_NOIOMMU
>>   	vfio_unregister_iommu_driver(&vfio_noiommu_ops);
>>   #endif
>> +	ida_destroy(&vfio.device_ida);
>>   	ida_destroy(&vfio.group_ida);
>>   	unregister_chrdev_region(vfio.group_devt, MINORMASK + 1);
>> +	class_destroy(vfio.device_class);
>> +	vfio.device_class = NULL;
>>   	class_destroy(vfio.class);
>>   	vfio.class = NULL;
>>   	misc_deregister(&vfio_dev);
>> diff --git a/include/linux/vfio.h b/include/linux/vfio.h
>> index f03447c8774d..5c13f74da1bb 100644
>> --- a/include/linux/vfio.h
>> +++ b/include/linux/vfio.h
>> @@ -45,7 +45,8 @@ struct vfio_device {
>>   	struct kvm *kvm;
>>   
>>   	/* Members below here are private, not for driver use */
>> -	struct kref kref;	/* object life cycle */
>> +	unsigned int index;
>> +	struct device device;	/* device.kref covers object life circle */
>>   	refcount_t refcount;	/* user count on registered device*/
>>   	unsigned int open_count;
>>   	struct completion comp;
> I am not totally clear about remaining 'struct device *dev;' in
> vfio_device struct. I see it used in some places. Is it supposed to
> disappear at some point?

no, Eric. *dev will not disappear, it stores the dev pointet passed in by
caller of vfio_init_device().

>> @@ -154,10 +155,9 @@ struct vfio_device *_vfio_alloc_device(size_t size, struct device *dev,
>>   int vfio_init_device(struct vfio_device *device, struct device *dev,
>>   		     const struct vfio_device_ops *ops);
>>   void vfio_free_device(struct vfio_device *device);
>> -void vfio_device_release(struct kref *kref);
>>   static inline void vfio_put_device(struct vfio_device *device)
>>   {
>> -	kref_put(&device->kref, vfio_device_release);
>> +	put_device(&device->device);
>>   }
>>   
>>   int vfio_register_group_dev(struct vfio_device *device);
> 
> Thanks
> 
> Eric
> 

-- 
Regards,
Yi Liu

Re: [PATCH v2 15/15] vfio: Add struct device to vfio_device

[Eric Auger]

On 9/8/22 11:17, Yi Liu wrote:
> On 2022/9/8 17:06, Eric Auger wrote:
>> Hi Kevin,
>>
>> On 9/1/22 16:37, Kevin Tian wrote:
>>> From: Yi Liu <yi.l.liu@intel.com>
>>>
>>> and replace kref. With it a 'vfio-dev/vfioX' node is created under the
>>> sysfs path of the parent, indicating the device is bound to a vfio
>>> driver, e.g.:
>>>
>>> /sys/devices/pci0000\:6f/0000\:6f\:01.0/vfio-dev/vfio0
>>>
>>> It is also a preparatory step toward adding cdev for supporting future
>>> device-oriented uAPI.
>>>
>>> Add Documentation/ABI/testing/sysfs-devices-vfio-dev.
>>>
>>> Also take this chance to rename chardev 'vfio' to 'vfio-group' in
>>> /proc/devices.
>>>
>>> Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
>>> Signed-off-by: Yi Liu <yi.l.liu@intel.com>
>>> Signed-off-by: Kevin Tian <kevin.tian@intel.com>
>>> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
>>> ---
>>>   .../ABI/testing/sysfs-devices-vfio-dev        |  8 +++
>>>   drivers/vfio/vfio_main.c                      | 67
>>> +++++++++++++++----
>>>   include/linux/vfio.h                          |  6 +-
>>>   3 files changed, 66 insertions(+), 15 deletions(-)
>>>   create mode 100644 Documentation/ABI/testing/sysfs-devices-vfio-dev
>>>
>>> diff --git a/Documentation/ABI/testing/sysfs-devices-vfio-dev
>>> b/Documentation/ABI/testing/sysfs-devices-vfio-dev
>>> new file mode 100644
>>> index 000000000000..e21424fd9666
>>> --- /dev/null
>>> +++ b/Documentation/ABI/testing/sysfs-devices-vfio-dev
>>> @@ -0,0 +1,8 @@
>>> +What:         /sys/.../<device>/vfio-dev/vfioX/
>>> +Date:         September 2022
>>> +Contact:     Yi Liu <yi.l.liu@intel.com>
>>> +Description:
>>> +         This directory is created when the device is bound to a
>>> +         vfio driver. The layout under this directory matches what
>>> +         exists for a standard 'struct device'. 'X' is a unique
>>> +         index marking this device in vfio.
>>> diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
>>> index bfa675d314ab..141f55c3faf5 100644
>>> --- a/drivers/vfio/vfio_main.c
>>> +++ b/drivers/vfio/vfio_main.c
>>> @@ -46,6 +46,8 @@ static struct vfio {
>>>       struct mutex            group_lock; /* locks group_list */
>>>       struct ida            group_ida;
>>>       dev_t                group_devt;
>>> +    struct class            *device_class;
>>> +    struct ida            device_ida;
>>>   } vfio;
>>>     struct vfio_iommu_driver {
>>> @@ -483,12 +485,13 @@ static struct vfio_device
>>> *vfio_group_get_device(struct vfio_group *group,
>>>    * VFIO driver API
>>>    */
>>>   /* Release helper called by vfio_put_device() */
>>> -void vfio_device_release(struct kref *kref)
>>> +static void vfio_device_release(struct device *dev)
>>>   {
>>>       struct vfio_device *device =
>>> -            container_of(kref, struct vfio_device, kref);
>>> +            container_of(dev, struct vfio_device, device);
>>>         vfio_release_device_set(device);
>>> +    ida_free(&vfio.device_ida, device->index);
>>>         /*
>>>        * kvfree() cannot be done here due to a life cycle mess in
>>> @@ -498,7 +501,6 @@ void vfio_device_release(struct kref *kref)
>>>        */
>>>       device->ops->release(device);
>>>   }
>>> -EXPORT_SYMBOL_GPL(vfio_device_release);
>>>     /*
>>>    * Alloc and initialize vfio_device so it can be registered to vfio
>>> @@ -546,6 +548,13 @@ int vfio_init_device(struct vfio_device
>>> *device, struct device *dev,
>>>   {
>>>       int ret;
>>>   +    ret = ida_alloc_max(&vfio.device_ida, MINORMASK, GFP_KERNEL);
>>> +    if (ret < 0) {
>>> +        dev_dbg(dev, "Error to alloc index\n");
>>> +        return ret;
>>> +    }
>>> +
>>> +    device->index = ret;
>>>       init_completion(&device->comp);
>>>       device->dev = dev;
>>>       device->ops = ops;
>>> @@ -556,11 +565,15 @@ int vfio_init_device(struct vfio_device
>>> *device, struct device *dev,
>>>               goto out_uninit;
>>>       }
>>>   -    kref_init(&device->kref);
>>> +    device_initialize(&device->device);
>>> +    device->device.release = vfio_device_release;
>>> +    device->device.class = vfio.device_class;
>>> +    device->device.parent = device->dev;
>>>       return 0;
>>>     out_uninit:
>>>       vfio_release_device_set(device);
>>> +    ida_free(&vfio.device_ida, device->index);
>>>       return ret;
>>>   }
>>>   EXPORT_SYMBOL_GPL(vfio_init_device);
>>> @@ -657,6 +670,7 @@ static int __vfio_register_dev(struct
>>> vfio_device *device,
>>>           struct vfio_group *group)
>>>   {
>>>       struct vfio_device *existing_device;
>>> +    int ret;
>>>         if (IS_ERR(group))
>>>           return PTR_ERR(group);
>>> @@ -673,16 +687,21 @@ static int __vfio_register_dev(struct
>>> vfio_device *device,
>>>           dev_WARN(device->dev, "Device already exists on group %d\n",
>>>                iommu_group_id(group->iommu_group));
>>>           vfio_device_put_registration(existing_device);
>>> -        if (group->type == VFIO_NO_IOMMU ||
>>> -            group->type == VFIO_EMULATED_IOMMU)
>>> -            iommu_group_remove_device(device->dev);
>>> -        vfio_group_put(group);
>>> -        return -EBUSY;
>>> +        ret = -EBUSY;
>>> +        goto err_out;
>>>       }
>>>         /* Our reference on group is moved to the device */
>>>       device->group = group;
>>>   +    ret = dev_set_name(&device->device, "vfio%d", device->index);
>>> +    if (ret)
>>> +        goto err_out;
>>> +
>>> +    ret = device_add(&device->device);
>>> +    if (ret)
>>> +        goto err_out;
>>> +
>>>       /* Refcounting can't start until the driver calls register */
>>>       refcount_set(&device->refcount, 1);
>>>   @@ -692,6 +711,12 @@ static int __vfio_register_dev(struct
>>> vfio_device *device,
>>>       mutex_unlock(&group->device_lock);
>>>         return 0;
>>> +err_out:
>>> +    if (group->type == VFIO_NO_IOMMU ||
>>> +        group->type == VFIO_EMULATED_IOMMU)
>>> +        iommu_group_remove_device(device->dev);
>>> +    vfio_group_put(group);
>>> +    return ret;
>>>   }
>>>     int vfio_register_group_dev(struct vfio_device *device)
>>> @@ -779,6 +804,9 @@ void vfio_unregister_group_dev(struct
>>> vfio_device *device)
>>>       group->dev_counter--;
>>>       mutex_unlock(&group->device_lock);
>>>   +    /* Balances device_add in register path */
>>> +    device_del(&device->device);
>>> +
>>>       if (group->type == VFIO_NO_IOMMU || group->type ==
>>> VFIO_EMULATED_IOMMU)
>>>           iommu_group_remove_device(device->dev);
>>>   @@ -2145,6 +2173,7 @@ static int __init vfio_init(void)
>>>       int ret;
>>>         ida_init(&vfio.group_ida);
>>> +    ida_init(&vfio.device_ida);
>>>       mutex_init(&vfio.group_lock);
>>>       mutex_init(&vfio.iommu_drivers_lock);
>>>       INIT_LIST_HEAD(&vfio.group_list);
>>> @@ -2160,12 +2189,20 @@ static int __init vfio_init(void)
>>>       vfio.class = class_create(THIS_MODULE, "vfio");
>>>       if (IS_ERR(vfio.class)) {
>>>           ret = PTR_ERR(vfio.class);
>>> -        goto err_class;
>>> +        goto err_group_class;
>>>       }
>>>         vfio.class->devnode = vfio_devnode;
>>>   -    ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1,
>>> "vfio");
>>> +    /* /sys/class/vfio-dev/vfioX */
>>> +    vfio.device_class = class_create(THIS_MODULE, "vfio-dev");
>>> +    if (IS_ERR(vfio.device_class)) {
>>> +        ret = PTR_ERR(vfio.device_class);
>>> +        goto err_dev_class;
>>> +    }
>>> +
>>> +    ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1,
>>> +                  "vfio-group");
>>>       if (ret)
>>>           goto err_alloc_chrdev;
>>>   @@ -2181,9 +2218,12 @@ static int __init vfio_init(void)
>>>   err_driver_register:
>>>       unregister_chrdev_region(vfio.group_devt, MINORMASK + 1);
>>>   err_alloc_chrdev:
>>> +    class_destroy(vfio.device_class);
>>> +    vfio.device_class = NULL;
>>> +err_dev_class:
>>>       class_destroy(vfio.class);
>>>       vfio.class = NULL;
>>> -err_class:
>>> +err_group_class:
>>>       misc_deregister(&vfio_dev);
>>>       return ret;
>>>   }
>>> @@ -2195,8 +2235,11 @@ static void __exit vfio_cleanup(void)
>>>   #ifdef CONFIG_VFIO_NOIOMMU
>>>       vfio_unregister_iommu_driver(&vfio_noiommu_ops);
>>>   #endif
>>> +    ida_destroy(&vfio.device_ida);
>>>       ida_destroy(&vfio.group_ida);
>>>       unregister_chrdev_region(vfio.group_devt, MINORMASK + 1);
>>> +    class_destroy(vfio.device_class);
>>> +    vfio.device_class = NULL;
>>>       class_destroy(vfio.class);
>>>       vfio.class = NULL;
>>>       misc_deregister(&vfio_dev);
>>> diff --git a/include/linux/vfio.h b/include/linux/vfio.h
>>> index f03447c8774d..5c13f74da1bb 100644
>>> --- a/include/linux/vfio.h
>>> +++ b/include/linux/vfio.h
>>> @@ -45,7 +45,8 @@ struct vfio_device {
>>>       struct kvm *kvm;
>>>         /* Members below here are private, not for driver use */
>>> -    struct kref kref;    /* object life cycle */
>>> +    unsigned int index;
>>> +    struct device device;    /* device.kref covers object life
>>> circle */
>>>       refcount_t refcount;    /* user count on registered device*/
>>>       unsigned int open_count;
>>>       struct completion comp;
>> I am not totally clear about remaining 'struct device *dev;' in
>> vfio_device struct. I see it used in some places. Is it supposed to
>> disappear at some point?
>
> no, Eric. *dev will not disappear, it stores the dev pointet passed in by
> caller of vfio_init_device().

yeah I see but you have device->device.parent = device->dev;

Eric
>
>>> @@ -154,10 +155,9 @@ struct vfio_device *_vfio_alloc_device(size_t
>>> size, struct device *dev,
>>>   int vfio_init_device(struct vfio_device *device, struct device *dev,
>>>                const struct vfio_device_ops *ops);
>>>   void vfio_free_device(struct vfio_device *device);
>>> -void vfio_device_release(struct kref *kref);
>>>   static inline void vfio_put_device(struct vfio_device *device)
>>>   {
>>> -    kref_put(&device->kref, vfio_device_release);
>>> +    put_device(&device->device);
>>>   }
>>>     int vfio_register_group_dev(struct vfio_device *device);
>>
>> Thanks
>>
>> Eric
>>
>

Re: [PATCH v2 15/15] vfio: Add struct device to vfio_device

[Jason Gunthorpe]

On Thu, Sep 08, 2022 at 11:39:07AM +0200, Eric Auger wrote:

> >> I am not totally clear about remaining 'struct device *dev;' in
> >> vfio_device struct. I see it used in some places. Is it supposed to
> >> disappear at some point?
> >
> > no, Eric. *dev will not disappear, it stores the dev pointet passed in by
> > caller of vfio_init_device().
> 
> yeah I see but you have device->device.parent = device->dev;

IIRC we have a number of these redundancies now, often the drivers
store another copy of the dev too.

A significant use of dev is for printing things, what should be done
here is to create a subsystem wide vfio_warn/etc that takes in the
vfio_device, and then print properly from there. Now that we have a
struct device all the prints should also include the VFIO struct
device name, and then the PCI device perhaps in brackets.

Jason

RE: [PATCH v2 15/15] vfio: Add struct device to vfio_device

[Tian, Kevin]

> From: Jason Gunthorpe
> Sent: Thursday, September 8, 2022 8:37 PM
> 
> On Thu, Sep 08, 2022 at 11:39:07AM +0200, Eric Auger wrote:
> 
> > >> I am not totally clear about remaining 'struct device *dev;' in
> > >> vfio_device struct. I see it used in some places. Is it supposed to
> > >> disappear at some point?
> > >
> > > no, Eric. *dev will not disappear, it stores the dev pointet passed in by
> > > caller of vfio_init_device().
> >
> > yeah I see but you have device->device.parent = device->dev;
> 
> IIRC we have a number of these redundancies now, often the drivers
> store another copy of the dev too.
> 
> A significant use of dev is for printing things, what should be done
> here is to create a subsystem wide vfio_warn/etc that takes in the
> vfio_device, and then print properly from there. Now that we have a
> struct device all the prints should also include the VFIO struct
> device name, and then the PCI device perhaps in brackets.
> 

Let me handle it in a separate patch (after this series).