Re: [PATCH 3/9] vfio/mdev: Pass in a struct vfio_device * to vfio_pin/unpin_pages()

[Tony Krowiak <akrowiak@linux.ibm.com>]

On 4/12/22 11:53 AM, Jason Gunthorpe wrote:
> Every caller has a readily available vfio_device pointer, use that instead
> of passing in a generic struct device. The struct vfio_device already
> contains the group we need so this avoids complexity, extra refcountings,
> and a confusing lifecycle model.
>
> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
> ---
>   .../driver-api/vfio-mediated-device.rst       |  4 +-
>   drivers/s390/cio/vfio_ccw_cp.c                |  6 +--
>   drivers/s390/crypto/vfio_ap_ops.c             |  8 ++--
>   drivers/vfio/vfio.c                           | 40 ++++++-------------
>   include/linux/vfio.h                          |  4 +-
>   5 files changed, 24 insertions(+), 38 deletions(-)
>
> diff --git a/Documentation/driver-api/vfio-mediated-device.rst b/Documentation/driver-api/vfio-mediated-device.rst
> index 9f26079cacae35..6aeca741dc9be1 100644
> --- a/Documentation/driver-api/vfio-mediated-device.rst
> +++ b/Documentation/driver-api/vfio-mediated-device.rst
> @@ -279,10 +279,10 @@ Translation APIs for Mediated Devices
>   The following APIs are provided for translating user pfn to host pfn in a VFIO
>   driver::
>   
> -	extern int vfio_pin_pages(struct device *dev, unsigned long *user_pfn,
> +	extern int vfio_pin_pages(struct vfio_device *vdev, unsigned long *user_pfn,
>   				  int npage, int prot, unsigned long *phys_pfn);
>   
> -	extern int vfio_unpin_pages(struct device *dev, unsigned long *user_pfn,
> +	extern int vfio_unpin_pages(struct vfio_device *vdev, unsigned long *user_pfn,
>   				    int npage);
>   
>   These functions call back into the back-end IOMMU module by using the pin_pages
>
> diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
> index 69768061cd7bd9..a10b3369d76c41 100644
> --- a/drivers/s390/crypto/vfio_ap_ops.c
> +++ b/drivers/s390/crypto/vfio_ap_ops.c
> @@ -124,7 +124,7 @@ static void vfio_ap_free_aqic_resources(struct vfio_ap_queue *q)
>   		q->saved_isc = VFIO_AP_ISC_INVALID;
>   	}
>   	if (q->saved_pfn && !WARN_ON(!q->matrix_mdev)) {
> -		vfio_unpin_pages(mdev_dev(q->matrix_mdev->mdev),
> +		vfio_unpin_pages(&q->matrix_mdev->vdev,
>   				 &q->saved_pfn, 1);
>   		q->saved_pfn = 0;
>   	}
> @@ -258,7 +258,7 @@ static struct ap_queue_status vfio_ap_irq_enable(struct vfio_ap_queue *q,
>   		return status;
>   	}
>   
> -	ret = vfio_pin_pages(mdev_dev(q->matrix_mdev->mdev), &g_pfn, 1,
> +	ret = vfio_pin_pages(&q->matrix_mdev->vdev, &g_pfn, 1,
>   			     IOMMU_READ | IOMMU_WRITE, &h_pfn);
>   	switch (ret) {
>   	case 1:
> @@ -301,7 +301,7 @@ static struct ap_queue_status vfio_ap_irq_enable(struct vfio_ap_queue *q,
>   		break;
>   	case AP_RESPONSE_OTHERWISE_CHANGED:
>   		/* We could not modify IRQ setings: clear new configuration */
> -		vfio_unpin_pages(mdev_dev(q->matrix_mdev->mdev), &g_pfn, 1);
> +		vfio_unpin_pages(&q->matrix_mdev->vdev, &g_pfn, 1);
>   		kvm_s390_gisc_unregister(kvm, isc);
>   		break;
>   	default:
> @@ -1250,7 +1250,7 @@ static int vfio_ap_mdev_iommu_notifier(struct notifier_block *nb,
>   		struct vfio_iommu_type1_dma_unmap *unmap = data;
>   		unsigned long g_pfn = unmap->iova >> PAGE_SHIFT;
>   
> -		vfio_unpin_pages(mdev_dev(matrix_mdev->mdev), &g_pfn, 1);
> +		vfio_unpin_pages(&matrix_mdev->vdev, &g_pfn, 1);
>   		return NOTIFY_OK;
>   	}

The vfio_ap snippet:
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>

>   
>