Re: [PATCH v5 06/10] vfio-iommufd: Add helper to retrieve iommufd_ctx and devid for vfio_device

Alex Williamson
2023-05-17T18:16:11Z

On Sat, 13 May 2023 06:21:32 -0700
Yi Liu <yi.l.liu@intel.com> wrote:

> This is needed by the vfio-pci driver to report affected devices in the
> hot reset for a given device.
>
> Signed-off-by: Yi Liu <yi.l.liu@intel.com>
> ---
> drivers/iommu/iommufd/device.c | 24 ++++++++++++++++++++++++
> drivers/vfio/iommufd.c | 20 ++++++++++++++++++++
> include/linux/iommufd.h | 6 ++++++
> include/linux/vfio.h | 14 ++++++++++++++
> 4 files changed, 64 insertions(+)
>
> diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c
> index 4f9b2142274c..81466b97023f 100644
> --- a/drivers/iommu/iommufd/device.c
> +++ b/drivers/iommu/iommufd/device.c
> @@ -116,6 +116,18 @@ void iommufd_device_unbind(struct iommufd_device *idev)
> }
> EXPORT_SYMBOL_NS_GPL(iommufd_device_unbind, IOMMUFD);
>
> +struct iommufd_ctx *iommufd_device_to_ictx(struct iommufd_device *idev)
> +{
> + return idev->ictx;
> +}
> +EXPORT_SYMBOL_NS_GPL(iommufd_device_to_ictx, IOMMUFD);
> +
> +u32 iommufd_device_to_id(struct iommufd_device *idev)
> +{
> + return idev->obj.id;
> +}
> +EXPORT_SYMBOL_NS_GPL(iommufd_device_to_id, IOMMUFD);
> +
> static int iommufd_device_setup_msi(struct iommufd_device *idev,
> struct iommufd_hw_pagetable *hwpt,
> phys_addr_t sw_msi_start)
> @@ -463,6 +475,18 @@ void iommufd_access_destroy(struct iommufd_access *access)
> }
> EXPORT_SYMBOL_NS_GPL(iommufd_access_destroy, IOMMUFD);
>
> +struct iommufd_ctx *iommufd_access_to_ictx(struct iommufd_access *access)
> +{
> + return access->ictx;
> +}
> +EXPORT_SYMBOL_NS_GPL(iommufd_access_to_ictx, IOMMUFD);
> +
> +u32 iommufd_access_to_id(struct iommufd_access *access)
> +{
> + return access->obj.id;
> +}
> +EXPORT_SYMBOL_NS_GPL(iommufd_access_to_id, IOMMUFD);
> +
> int iommufd_access_attach(struct iommufd_access *access, u32 ioas_id)
> {
> struct iommufd_ioas *new_ioas;
> diff --git a/drivers/vfio/iommufd.c b/drivers/vfio/iommufd.c
> index c1379e826052..a18e920be164 100644
> --- a/drivers/vfio/iommufd.c
> +++ b/drivers/vfio/iommufd.c
> @@ -105,6 +105,26 @@ void vfio_iommufd_unbind(struct vfio_device *vdev)
> vdev->ops->unbind_iommufd(vdev);
> }
>
> +struct iommufd_ctx *vfio_iommufd_physical_ictx(struct vfio_device *vdev)
> +{
> + if (vdev->iommufd_device)
> + return iommufd_device_to_ictx(vdev->iommufd_device);
> + if (vdev->noiommu_access)
> + return iommufd_access_to_ictx(vdev->noiommu_access);
> + return NULL;
> +}
> +EXPORT_SYMBOL_GPL(vfio_iommufd_physical_ictx);
> +
> +int vfio_iommufd_physical_devid(struct vfio_device *vdev)
> +{
> + if (vdev->iommufd_device)
> + return iommufd_device_to_id(vdev->iommufd_device);
> + if (vdev->noiommu_access)
> + return iommufd_access_to_id(vdev->noiommu_access);
> + return -EINVAL;
> +}
> +EXPORT_SYMBOL_GPL(vfio_iommufd_physical_devid);

I think these exemplify that it would be better if both emulated and
noiommu use the same iommufd_access pointer. Thanks,

Alex

> +
> /*
> * The physical standard ops mean that the iommufd_device is bound to the
> * physical device vdev->dev that was provided to vfio_init_group_dev(). Drivers
> diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h
> index 1129a36a74c4..68cd65274e28 100644
> --- a/include/linux/iommufd.h
> +++ b/include/linux/iommufd.h
> @@ -24,6 +24,9 @@ void iommufd_device_unbind(struct iommufd_device *idev);
> int iommufd_device_attach(struct iommufd_device *idev, u32 *pt_id);
> void iommufd_device_detach(struct iommufd_device *idev);
>
> +struct iommufd_ctx *iommufd_device_to_ictx(struct iommufd_device *idev);
> +u32 iommufd_device_to_id(struct iommufd_device *idev);
> +
> struct iommufd_access_ops {
> u8 needs_pin_pages : 1;
> void (*unmap)(void *data, unsigned long iova, unsigned long length);
> @@ -45,6 +48,9 @@ iommufd_access_create(struct iommufd_ctx *ictx,
> void iommufd_access_destroy(struct iommufd_access *access);
> int iommufd_access_attach(struct iommufd_access *access, u32 ioas_id);
>
> +struct iommufd_ctx *iommufd_access_to_ictx(struct iommufd_access *access);
> +u32 iommufd_access_to_id(struct iommufd_access *access);
> +
> void iommufd_ctx_get(struct iommufd_ctx *ictx);
>
> #if IS_ENABLED(CONFIG_IOMMUFD)
> diff --git a/include/linux/vfio.h b/include/linux/vfio.h
> index a61130bc06a2..fcbe084b18c8 100644
> --- a/include/linux/vfio.h
> +++ b/include/linux/vfio.h
> @@ -115,6 +115,8 @@ struct vfio_device_ops {
> };
>
> #if IS_ENABLED(CONFIG_IOMMUFD)
> +struct iommufd_ctx *vfio_iommufd_physical_ictx(struct vfio_device *vdev);
> +int vfio_iommufd_physical_devid(struct vfio_device *vdev);
> int vfio_iommufd_physical_bind(struct vfio_device *vdev,
> struct iommufd_ctx *ictx, u32 *out_device_id);
> void vfio_iommufd_physical_unbind(struct vfio_device *vdev);
> @@ -124,6 +126,18 @@ int vfio_iommufd_emulated_bind(struct vfio_device *vdev,
> void vfio_iommufd_emulated_unbind(struct vfio_device *vdev);
> int vfio_iommufd_emulated_attach_ioas(struct vfio_device *vdev, u32 *pt_id);
> #else
> +static inline struct iommufd_ctx *
> +vfio_iommufd_physical_ictx(struct vfio_device *vdev)
> +{
> + return NULL;
> +}
> +
> +static inline int
> +vfio_iommufd_physical_devid(struct vfio_device *vdev)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> #define vfio_iommufd_physical_bind \
> ((int (*)(struct vfio_device *vdev, struct iommufd_ctx *ictx, \
> u32 *out_device_id)) NULL)