Re: [Intel-gfx] [PATCH v12 06/24] vfio: Pass struct vfio_device_file * to vfio_device_open/close()

[Alex Williamson <alex.williamson@redhat.com>]

On Fri,  2 Jun 2023 05:16:35 -0700
Yi Liu <yi.l.liu@intel.com> wrote:

> This avoids passing too much parameters in multiple functions. Per the
> input parameter change, rename the function to be vfio_df_open/close().
> 
> Reviewed-by: Kevin Tian <kevin.tian@intel.com>
> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
> Reviewed-by: Eric Auger <eric.auger@redhat.com>
> Tested-by: Terrence Xu <terrence.xu@intel.com>
> Tested-by: Nicolin Chen <nicolinc@nvidia.com>
> Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
> Tested-by: Yanting Jiang <yanting.jiang@intel.com>
> Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
> Signed-off-by: Yi Liu <yi.l.liu@intel.com>
> ---
>  drivers/vfio/group.c     | 20 ++++++++++++++------
>  drivers/vfio/vfio.h      |  8 ++++----
>  drivers/vfio/vfio_main.c | 25 +++++++++++++++----------
>  3 files changed, 33 insertions(+), 20 deletions(-)
> 
> diff --git a/drivers/vfio/group.c b/drivers/vfio/group.c
> index b56e19d2a02d..caf53716ddb2 100644
> --- a/drivers/vfio/group.c
> +++ b/drivers/vfio/group.c
> @@ -169,8 +169,9 @@ static void vfio_device_group_get_kvm_safe(struct vfio_device *device)
>  	spin_unlock(&device->group->kvm_ref_lock);
>  }
>  
> -static int vfio_device_group_open(struct vfio_device *device)
> +static int vfio_df_group_open(struct vfio_device_file *df)
>  {
> +	struct vfio_device *device = df->device;
>  	int ret;
>  
>  	mutex_lock(&device->group->group_lock);
> @@ -190,7 +191,11 @@ static int vfio_device_group_open(struct vfio_device *device)
>  	if (device->open_count == 0)
>  		vfio_device_group_get_kvm_safe(device);
>  
> -	ret = vfio_device_open(device, device->group->iommufd);
> +	df->iommufd = device->group->iommufd;
> +
> +	ret = vfio_df_open(df);
> +	if (ret)
> +		df->iommufd = NULL;
>  
>  	if (device->open_count == 0)
>  		vfio_device_put_kvm(device);
> @@ -202,12 +207,15 @@ static int vfio_device_group_open(struct vfio_device *device)
>  	return ret;
>  }
>  
> -void vfio_device_group_close(struct vfio_device *device)
> +void vfio_df_group_close(struct vfio_device_file *df)
>  {
> +	struct vfio_device *device = df->device;
> +
>  	mutex_lock(&device->group->group_lock);
>  	mutex_lock(&device->dev_set->lock);
>  
> -	vfio_device_close(device, device->group->iommufd);
> +	vfio_df_close(df);
> +	df->iommufd = NULL;
>  
>  	if (device->open_count == 0)
>  		vfio_device_put_kvm(device);
> @@ -228,7 +236,7 @@ static struct file *vfio_device_open_file(struct vfio_device *device)
>  		goto err_out;
>  	}
>  
> -	ret = vfio_device_group_open(device);
> +	ret = vfio_df_group_open(df);
>  	if (ret)
>  		goto err_free;
>  
> @@ -260,7 +268,7 @@ static struct file *vfio_device_open_file(struct vfio_device *device)
>  	return filep;
>  
>  err_close_device:
> -	vfio_device_group_close(device);
> +	vfio_df_group_close(df);
>  err_free:
>  	kfree(df);
>  err_out:
> diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h
> index 69e1a0692b06..f9eb52eb9ed7 100644
> --- a/drivers/vfio/vfio.h
> +++ b/drivers/vfio/vfio.h
> @@ -20,13 +20,13 @@ struct vfio_device_file {
>  	struct vfio_device *device;
>  	spinlock_t kvm_ref_lock; /* protect kvm field */
>  	struct kvm *kvm;
> +	struct iommufd_ctx *iommufd; /* protected by struct vfio_device_set::lock */
>  };
>  
>  void vfio_device_put_registration(struct vfio_device *device);
>  bool vfio_device_try_get_registration(struct vfio_device *device);
> -int vfio_device_open(struct vfio_device *device, struct iommufd_ctx *iommufd);
> -void vfio_device_close(struct vfio_device *device,
> -		       struct iommufd_ctx *iommufd);
> +int vfio_df_open(struct vfio_device_file *df);
> +void vfio_df_close(struct vfio_device_file *df);
>  struct vfio_device_file *
>  vfio_allocate_device_file(struct vfio_device *device);
>  
> @@ -91,7 +91,7 @@ void vfio_device_group_register(struct vfio_device *device);
>  void vfio_device_group_unregister(struct vfio_device *device);
>  int vfio_device_group_use_iommu(struct vfio_device *device);
>  void vfio_device_group_unuse_iommu(struct vfio_device *device);
> -void vfio_device_group_close(struct vfio_device *device);
> +void vfio_df_group_close(struct vfio_device_file *df);
>  struct vfio_group *vfio_group_from_file(struct file *file);
>  bool vfio_group_enforced_coherent(struct vfio_group *group);
>  void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm);
> diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
> index 8ef9210ad2aa..a3c5817fc545 100644
> --- a/drivers/vfio/vfio_main.c
> +++ b/drivers/vfio/vfio_main.c
> @@ -434,9 +434,10 @@ vfio_allocate_device_file(struct vfio_device *device)
>  	return df;
>  }
>  
> -static int vfio_device_first_open(struct vfio_device *device,
> -				  struct iommufd_ctx *iommufd)
> +static int vfio_device_first_open(struct vfio_device_file *df)
>  {
> +	struct vfio_device *device = df->device;
> +	struct iommufd_ctx *iommufd = df->iommufd;
>  	int ret;
>  
>  	lockdep_assert_held(&device->dev_set->lock);
> @@ -468,9 +469,11 @@ static int vfio_device_first_open(struct vfio_device *device,
>  	return ret;
>  }
>  
> -static void vfio_device_last_close(struct vfio_device *device,
> -				   struct iommufd_ctx *iommufd)
> +static void vfio_device_last_close(struct vfio_device_file *df)

Shouldn't these now be vfio_df_... functions too?  Thanks,

Ale

>  {
> +	struct vfio_device *device = df->device;
> +	struct iommufd_ctx *iommufd = df->iommufd;
> +
>  	lockdep_assert_held(&device->dev_set->lock);
>  
>  	if (device->ops->close_device)
> @@ -482,15 +485,16 @@ static void vfio_device_last_close(struct vfio_device *device,
>  	module_put(device->dev->driver->owner);
>  }
>  
> -int vfio_device_open(struct vfio_device *device, struct iommufd_ctx *iommufd)
> +int vfio_df_open(struct vfio_device_file *df)
>  {
> +	struct vfio_device *device = df->device;
>  	int ret = 0;
>  
>  	lockdep_assert_held(&device->dev_set->lock);
>  
>  	device->open_count++;
>  	if (device->open_count == 1) {
> -		ret = vfio_device_first_open(device, iommufd);
> +		ret = vfio_device_first_open(df);
>  		if (ret)
>  			device->open_count--;
>  	}
> @@ -498,14 +502,15 @@ int vfio_device_open(struct vfio_device *device, struct iommufd_ctx *iommufd)
>  	return ret;
>  }
>  
> -void vfio_device_close(struct vfio_device *device,
> -		       struct iommufd_ctx *iommufd)
> +void vfio_df_close(struct vfio_device_file *df)
>  {
> +	struct vfio_device *device = df->device;
> +
>  	lockdep_assert_held(&device->dev_set->lock);
>  
>  	vfio_assert_device_open(device);
>  	if (device->open_count == 1)
> -		vfio_device_last_close(device, iommufd);
> +		vfio_device_last_close(df);
>  	device->open_count--;
>  }
>  
> @@ -550,7 +555,7 @@ static int vfio_device_fops_release(struct inode *inode, struct file *filep)
>  	struct vfio_device_file *df = filep->private_data;
>  	struct vfio_device *device = df->device;
>  
> -	vfio_device_group_close(device);
> +	vfio_df_group_close(df);
>  
>  	vfio_device_put_registration(device);
>