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Commit a7170720 authored by Shameer Kolothum's avatar Shameer Kolothum Committed by Alex Williamson
Browse files

vfio/type1: Add IOVA range capability support 



This allows the user-space to retrieve the supported IOVA
range(s), excluding any non-relaxable reserved regions. The
implementation is based on capability chains, added to
VFIO_IOMMU_GET_INFO ioctl.

Signed-off-by: default avatarShameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Reviewed-by: default avatarEric Auger <eric.auger@redhat.com>
Signed-off-by: default avatarAlex Williamson <alex.williamson@redhat.com>
parent 9b77e5c7

drivers/vfio/vfio_iommu_type1.c

+101 −0
Original line number Diff line number Diff line
@@ -2138,6 +2138,73 @@ static int vfio_domains_have_iommu_cache(struct vfio_iommu *iommu) 
	return ret;

}



static int vfio_iommu_iova_add_cap(struct vfio_info_cap *caps,

		 struct vfio_iommu_type1_info_cap_iova_range *cap_iovas,

		 size_t size)

{

	struct vfio_info_cap_header *header;

	struct vfio_iommu_type1_info_cap_iova_range *iova_cap;



	header = vfio_info_cap_add(caps, size,

				   VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE, 1);

	if (IS_ERR(header))

		return PTR_ERR(header);



	iova_cap = container_of(header,

				struct vfio_iommu_type1_info_cap_iova_range,

				header);

	iova_cap->nr_iovas = cap_iovas->nr_iovas;

	memcpy(iova_cap->iova_ranges, cap_iovas->iova_ranges,

	       cap_iovas->nr_iovas * sizeof(*cap_iovas->iova_ranges));

	return 0;

}



static int vfio_iommu_iova_build_caps(struct vfio_iommu *iommu,

				      struct vfio_info_cap *caps)

{

	struct vfio_iommu_type1_info_cap_iova_range *cap_iovas;

	struct vfio_iova *iova;

	size_t size;

	int iovas = 0, i = 0, ret;



	mutex_lock(&iommu->lock);



	list_for_each_entry(iova, &iommu->iova_list, list)

		iovas++;



	if (!iovas) {

		/*

		 * Return 0 as a container with a single mdev device

		 * will have an empty list

		 */

		ret = 0;

		goto out_unlock;

	}



	size = sizeof(*cap_iovas) + (iovas * sizeof(*cap_iovas->iova_ranges));



	cap_iovas = kzalloc(size, GFP_KERNEL);

	if (!cap_iovas) {

		ret = -ENOMEM;

		goto out_unlock;

	}



	cap_iovas->nr_iovas = iovas;



	list_for_each_entry(iova, &iommu->iova_list, list) {

		cap_iovas->iova_ranges[i].start = iova->start;

		cap_iovas->iova_ranges[i].end = iova->end;

		i++;

	}



	ret = vfio_iommu_iova_add_cap(caps, cap_iovas, size);



	kfree(cap_iovas);

out_unlock:

	mutex_unlock(&iommu->lock);

	return ret;

}



static long vfio_iommu_type1_ioctl(void *iommu_data,

				   unsigned int cmd, unsigned long arg)

{
@@ -2159,19 +2226,53 @@ static long vfio_iommu_type1_ioctl(void *iommu_data, 
		}

	} else if (cmd == VFIO_IOMMU_GET_INFO) {

		struct vfio_iommu_type1_info info;

		struct vfio_info_cap caps = { .buf = NULL, .size = 0 };

		unsigned long capsz;

		int ret;



		minsz = offsetofend(struct vfio_iommu_type1_info, iova_pgsizes);



		/* For backward compatibility, cannot require this */

		capsz = offsetofend(struct vfio_iommu_type1_info, cap_offset);



		if (copy_from_user(&info, (void __user *)arg, minsz))

			return -EFAULT;



		if (info.argsz < minsz)

			return -EINVAL;



		if (info.argsz >= capsz) {

			minsz = capsz;

			info.cap_offset = 0; /* output, no-recopy necessary */

		}



		info.flags = VFIO_IOMMU_INFO_PGSIZES;



		info.iova_pgsizes = vfio_pgsize_bitmap(iommu);



		ret = vfio_iommu_iova_build_caps(iommu, &caps);

		if (ret)

			return ret;



		if (caps.size) {

			info.flags |= VFIO_IOMMU_INFO_CAPS;



			if (info.argsz < sizeof(info) + caps.size) {

				info.argsz = sizeof(info) + caps.size;

			} else {

				vfio_info_cap_shift(&caps, sizeof(info));

				if (copy_to_user((void __user *)arg +

						sizeof(info), caps.buf,

						caps.size)) {

					kfree(caps.buf);

					return -EFAULT;

				}

				info.cap_offset = sizeof(info);

			}



			kfree(caps.buf);

		}



		return copy_to_user((void __user *)arg, &info, minsz) ?

			-EFAULT : 0;

include/uapi/linux/vfio.h

+25 −1
Original line number Diff line number Diff line
@@ -714,7 +714,31 @@ struct vfio_iommu_type1_info { 
	__u32	argsz;

	__u32	flags;

#define VFIO_IOMMU_INFO_PGSIZES (1 << 0)	/* supported page sizes info */

#define VFIO_IOMMU_INFO_CAPS	(1 << 1)	/* Info supports caps */

	__u64	iova_pgsizes;	/* Bitmap of supported page sizes */

	__u32   cap_offset;	/* Offset within info struct of first cap */

};



/*

 * The IOVA capability allows to report the valid IOVA range(s)

 * excluding any non-relaxable reserved regions exposed by

 * devices attached to the container. Any DMA map attempt

 * outside the valid iova range will return error.

 *

 * The structures below define version 1 of this capability.

 */

#define VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE  1



struct vfio_iova_range {

	__u64	start;

	__u64	end;

};



struct vfio_iommu_type1_info_cap_iova_range {

	struct	vfio_info_cap_header header;

	__u32	nr_iovas;

	__u32	reserved;

	struct	vfio_iova_range iova_ranges[];

};



#define VFIO_IOMMU_GET_INFO _IO(VFIO_TYPE, VFIO_BASE + 12)