RE: [PATCH 01/14] vfio: Move vfio_iommu_group_get() to vfio_register_group_dev()

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



> From: Christoph Hellwig <hch@xxxxxx>
> Sent: Thursday, August 26, 2021 12:19 AM
> 
> We don't need to hold a reference to the group in the driver as well as
> obtain a reference to the same group as the first thing
> vfio_register_group_dev() does.
> 
> Since the drivers never use the group move this all into the core code.
> 
> Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> ---
>  drivers/vfio/fsl-mc/vfio_fsl_mc.c            | 17 ++-----------
>  drivers/vfio/pci/vfio_pci_core.c             | 13 ++--------
>  drivers/vfio/platform/vfio_platform_common.c | 13 +---------
>  drivers/vfio/vfio.c                          | 25 ++++++--------------
>  include/linux/vfio.h                         |  3 ---
>  5 files changed, 12 insertions(+), 59 deletions(-)
> 
> diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc.c b/drivers/vfio/fsl-
> mc/vfio_fsl_mc.c
> index 0ead91bfa83867..9e838fed560339 100644
> --- a/drivers/vfio/fsl-mc/vfio_fsl_mc.c
> +++ b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
> @@ -505,22 +505,13 @@ static void vfio_fsl_uninit_device(struct
> vfio_fsl_mc_device *vdev)
> 
>  static int vfio_fsl_mc_probe(struct fsl_mc_device *mc_dev)
>  {
> -	struct iommu_group *group;
>  	struct vfio_fsl_mc_device *vdev;
>  	struct device *dev = &mc_dev->dev;
>  	int ret;
> 
> -	group = vfio_iommu_group_get(dev);
> -	if (!group) {
> -		dev_err(dev, "VFIO_FSL_MC: No IOMMU group\n");
> -		return -EINVAL;
> -	}
> -
>  	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
> -	if (!vdev) {
> -		ret = -ENOMEM;
> -		goto out_group_put;
> -	}
> +	if (!vdev)
> +		return -ENOMEM;
> 
>  	vfio_init_group_dev(&vdev->vdev, dev, &vfio_fsl_mc_ops);
>  	vdev->mc_dev = mc_dev;
> @@ -556,8 +547,6 @@ static int vfio_fsl_mc_probe(struct fsl_mc_device
> *mc_dev)
>  out_uninit:
>  	vfio_uninit_group_dev(&vdev->vdev);
>  	kfree(vdev);
> -out_group_put:
> -	vfio_iommu_group_put(group, dev);
>  	return ret;
>  }
> 
> @@ -574,8 +563,6 @@ static int vfio_fsl_mc_remove(struct fsl_mc_device
> *mc_dev)
> 
>  	vfio_uninit_group_dev(&vdev->vdev);
>  	kfree(vdev);
> -	vfio_iommu_group_put(mc_dev->dev.iommu_group, dev);
> -
>  	return 0;
>  }
> 
> diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
> index c67751948504af..4134dceab3f73b 100644
> --- a/drivers/vfio/pci/vfio_pci_core.c
> +++ b/drivers/vfio/pci/vfio_pci_core.c
> @@ -1807,7 +1807,6 @@
> 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;
> -	struct iommu_group *group;
>  	int ret;
> 
>  	if (pdev->hdr_type != PCI_HEADER_TYPE_NORMAL)
> @@ -1826,10 +1825,6 @@ int vfio_pci_core_register_device(struct
> vfio_pci_core_device *vdev)
>  		return -EBUSY;
>  	}
> 
> -	group = vfio_iommu_group_get(&pdev->dev);
> -	if (!group)
> -		return -EINVAL;
> -
>  	if (pci_is_root_bus(pdev->bus)) {
>  		ret = vfio_assign_device_set(&vdev->vdev, vdev);
>  	} else if (!pci_probe_reset_slot(pdev->slot)) {
> @@ -1843,10 +1838,10 @@ int vfio_pci_core_register_device(struct
> vfio_pci_core_device *vdev)
>  	}
> 
>  	if (ret)
> -		goto out_group_put;
> +		return ret;
>  	ret = vfio_pci_vf_init(vdev);
>  	if (ret)
> -		goto out_group_put;
> +		return ret;
>  	ret = vfio_pci_vga_init(vdev);
>  	if (ret)
>  		goto out_vf;
> @@ -1877,8 +1872,6 @@ int vfio_pci_core_register_device(struct
> vfio_pci_core_device *vdev)
>  		vfio_pci_set_power_state(vdev, PCI_D0);
>  out_vf:
>  	vfio_pci_vf_uninit(vdev);
> -out_group_put:
> -	vfio_iommu_group_put(group, &pdev->dev);
>  	return ret;
>  }
>  EXPORT_SYMBOL_GPL(vfio_pci_core_register_device);
> @@ -1894,8 +1887,6 @@ void vfio_pci_core_unregister_device(struct
> vfio_pci_core_device *vdev)
>  	vfio_pci_vf_uninit(vdev);
>  	vfio_pci_vga_uninit(vdev);
> 
> -	vfio_iommu_group_put(pdev->dev.iommu_group, &pdev->dev);
> -
>  	if (!disable_idle_d3)
>  		vfio_pci_set_power_state(vdev, PCI_D0);
>  }
> diff --git a/drivers/vfio/platform/vfio_platform_common.c
> b/drivers/vfio/platform/vfio_platform_common.c
> index 6af7ce7d619c25..256f55b84e70a0 100644
> --- a/drivers/vfio/platform/vfio_platform_common.c
> +++ b/drivers/vfio/platform/vfio_platform_common.c
> @@ -642,7 +642,6 @@ static int vfio_platform_of_probe(struct
> vfio_platform_device *vdev,
>  int vfio_platform_probe_common(struct vfio_platform_device *vdev,
>  			       struct device *dev)
>  {
> -	struct iommu_group *group;
>  	int ret;
> 
>  	vfio_init_group_dev(&vdev->vdev, dev, &vfio_platform_ops);
> @@ -663,24 +662,15 @@ int vfio_platform_probe_common(struct
> vfio_platform_device *vdev,
>  		goto out_uninit;
>  	}
> 
> -	group = vfio_iommu_group_get(dev);
> -	if (!group) {
> -		dev_err(dev, "No IOMMU group for device %s\n", vdev-
> >name);
> -		ret = -EINVAL;
> -		goto put_reset;
> -	}
> -
>  	ret = vfio_register_group_dev(&vdev->vdev);
>  	if (ret)
> -		goto put_iommu;
> +		goto put_reset;
> 
>  	mutex_init(&vdev->igate);
> 
>  	pm_runtime_enable(dev);
>  	return 0;
> 
> -put_iommu:
> -	vfio_iommu_group_put(group, dev);
>  put_reset:
>  	vfio_platform_put_reset(vdev);
>  out_uninit:
> @@ -696,7 +686,6 @@ void vfio_platform_remove_common(struct
> vfio_platform_device *vdev)
>  	pm_runtime_disable(vdev->device);
>  	vfio_platform_put_reset(vdev);
>  	vfio_uninit_group_dev(&vdev->vdev);
> -	vfio_iommu_group_put(vdev->vdev.dev->iommu_group, vdev-
> >vdev.dev);
>  }
>  EXPORT_SYMBOL_GPL(vfio_platform_remove_common);
> 
> diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
> index 3c034fe14ccb03..5bd520f0dc6107 100644
> --- a/drivers/vfio/vfio.c
> +++ b/drivers/vfio/vfio.c
> @@ -169,15 +169,7 @@ static void vfio_release_device_set(struct
> vfio_device *device)
>  	xa_unlock(&vfio_device_set_xa);
>  }
> 
> -/*
> - * vfio_iommu_group_{get,put} are only intended for VFIO bus driver probe
> - * and remove functions, any use cases other than acquiring the first
> - * reference for the purpose of calling vfio_register_group_dev() or
> removing
> - * that symmetric reference after vfio_unregister_group_dev() should use
> the raw
> - * iommu_group_{get,put} functions.  In particular, vfio_iommu_group_put()
> - * removes the device from the dummy group and cannot be nested.
> - */
> -struct iommu_group *vfio_iommu_group_get(struct device *dev)
> +static struct iommu_group *vfio_iommu_group_get(struct device *dev)
>  {
>  	struct iommu_group *group;
>  	int __maybe_unused ret;
> @@ -220,9 +212,8 @@ struct iommu_group *vfio_iommu_group_get(struct
> device *dev)
> 
>  	return group;
>  }
> -EXPORT_SYMBOL_GPL(vfio_iommu_group_get);
> 
> -void vfio_iommu_group_put(struct iommu_group *group, struct device
> *dev)
> +static void vfio_iommu_group_put(struct iommu_group *group, struct
> device *dev)
>  {
>  #ifdef CONFIG_VFIO_NOIOMMU
>  	if (iommu_group_get_iommudata(group) == &noiommu)
> @@ -231,7 +222,6 @@ void vfio_iommu_group_put(struct iommu_group
> *group, struct device *dev)
> 
>  	iommu_group_put(group);
>  }
> -EXPORT_SYMBOL_GPL(vfio_iommu_group_put);
> 
>  #ifdef CONFIG_VFIO_NOIOMMU
>  static void *vfio_noiommu_open(unsigned long arg)
> @@ -841,7 +831,7 @@ int vfio_register_group_dev(struct vfio_device
> *device)
>  	if (!device->dev_set)
>  		vfio_assign_device_set(device, device);
> 
> -	iommu_group = iommu_group_get(device->dev);
> +	iommu_group = vfio_iommu_group_get(device->dev);
>  	if (!iommu_group)
>  		return -EINVAL;
> 
> @@ -849,7 +839,7 @@ int vfio_register_group_dev(struct vfio_device
> *device)
>  	if (!group) {
>  		group = vfio_create_group(iommu_group);
>  		if (IS_ERR(group)) {
> -			iommu_group_put(iommu_group);
> +			vfio_iommu_group_put(iommu_group, device->dev);
>  			return PTR_ERR(group);
>  		}
>  	} else {
> @@ -857,7 +847,7 @@ int vfio_register_group_dev(struct vfio_device
> *device)
>  		 * A found vfio_group already holds a reference to the
>  		 * iommu_group.  A created vfio_group keeps the reference.
>  		 */
> -		iommu_group_put(iommu_group);
> +		vfio_iommu_group_put(iommu_group, device->dev);
>  	}
> 
>  	existing_device = vfio_group_get_device(group, device->dev);
> @@ -865,7 +855,7 @@ int vfio_register_group_dev(struct vfio_device
> *device)
>  		dev_WARN(device->dev, "Device already exists on
> group %d\n",
>  			 iommu_group_id(iommu_group));
>  		vfio_device_put(existing_device);
> -		vfio_group_put(group);
> +		vfio_iommu_group_put(iommu_group, device->dev);

semantics change? the removed line is about vfio_group instead of
iommu_group.

>  		return -EBUSY;
>  	}
> 
> @@ -1010,8 +1000,7 @@ void vfio_unregister_group_dev(struct vfio_device
> *device)
>  	if (list_empty(&group->device_list))
>  		wait_event(group->container_q, !group->container);
> 
> -	/* Matches the get in vfio_register_group_dev() */
> -	vfio_group_put(group);
> +	vfio_iommu_group_put(group->iommu_group, device->dev);

ditto

>  }
>  EXPORT_SYMBOL_GPL(vfio_unregister_group_dev);
> 
> diff --git a/include/linux/vfio.h b/include/linux/vfio.h
> index b53a9557884ada..f7083c2fd0d099 100644
> --- a/include/linux/vfio.h
> +++ b/include/linux/vfio.h
> @@ -71,9 +71,6 @@ struct vfio_device_ops {
>  	int	(*match)(struct vfio_device *vdev, char *buf);
>  };
> 
> -extern struct iommu_group *vfio_iommu_group_get(struct device *dev);
> -extern void vfio_iommu_group_put(struct iommu_group *group, struct
> device *dev);
> -
>  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);
> --
> 2.30.2





[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]

  Powered by Linux