Commit 7c44656a authored by Alex Mastro's avatar Alex Mastro Committed by Alex Williamson
Browse files

vfio: selftests: add iova range query helpers 



VFIO selftests need to map IOVAs from legally accessible ranges, which
could vary between hardware. Tests in vfio_dma_mapping_test.c are making
excessively strong assumptions about which IOVAs can be mapped.

Add vfio_iommu_iova_ranges(), which queries IOVA ranges from the
IOMMUFD or VFIO container associated with the device. The queried ranges
are normalized to IOMMUFD's iommu_iova_range representation so that
handling of IOVA ranges up the stack can be implementation-agnostic.
iommu_iova_range and vfio_iova_range are equivalent, so bias to using the
new interface's struct.

Query IOMMUFD's ranges with IOMMU_IOAS_IOVA_RANGES.
Query VFIO container's ranges with VFIO_IOMMU_GET_INFO and
VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE.

The underlying vfio_iommu_type1_info buffer-related functionality has
been kept generic so the same helpers can be used to query other
capability chain information, if needed.

Reviewed-by: default avatarDavid Matlack <dmatlack@google.com>
Tested-by: default avatarDavid Matlack <dmatlack@google.com>
Signed-off-by: default avatarAlex Mastro <amastro@fb.com>
Link: https://lore.kernel.org/r/20251111-iova-ranges-v3-1-7960244642c5@fb.com


Signed-off-by: default avatarAlex Williamson <alex@shazbot.org>
parent 6146a0f1

tools/testing/selftests/vfio/lib/include/vfio_util.h

+7 −1
Original line number Diff line number Diff line
@@ -4,9 +4,12 @@ 


#include <fcntl.h>

#include <string.h>

#include <linux/vfio.h>



#include <uapi/linux/types.h>

#include <linux/iommufd.h>

#include <linux/list.h>

#include <linux/pci_regs.h>

#include <linux/vfio.h>



#include "../../../kselftest.h"
@@ -206,6 +209,9 @@ struct vfio_pci_device *vfio_pci_device_init(const char *bdf, const char *iommu_ 
void vfio_pci_device_cleanup(struct vfio_pci_device *device);

void vfio_pci_device_reset(struct vfio_pci_device *device);



struct iommu_iova_range *vfio_pci_iova_ranges(struct vfio_pci_device *device,

					      u32 *nranges);



int __vfio_pci_dma_map(struct vfio_pci_device *device,

		       struct vfio_dma_region *region);

int __vfio_pci_dma_unmap(struct vfio_pci_device *device,

tools/testing/selftests/vfio/lib/vfio_pci_device.c

+172 −0
Original line number Diff line number Diff line
@@ -29,6 +29,178 @@ 
	VFIO_ASSERT_EQ(__ret, 0, "ioctl(%s, %s, %s) returned %d\n", #_fd, #_op, #_arg, __ret); \

} while (0)



static struct vfio_info_cap_header *next_cap_hdr(void *buf, u32 bufsz,

						 u32 *cap_offset)

{

	struct vfio_info_cap_header *hdr;



	if (!*cap_offset)

		return NULL;



	VFIO_ASSERT_LT(*cap_offset, bufsz);

	VFIO_ASSERT_GE(bufsz - *cap_offset, sizeof(*hdr));



	hdr = (struct vfio_info_cap_header *)((u8 *)buf + *cap_offset);

	*cap_offset = hdr->next;



	return hdr;

}



static struct vfio_info_cap_header *vfio_iommu_info_cap_hdr(struct vfio_iommu_type1_info *info,

							    u16 cap_id)

{

	struct vfio_info_cap_header *hdr;

	u32 cap_offset = info->cap_offset;

	u32 max_depth;

	u32 depth = 0;



	if (!(info->flags & VFIO_IOMMU_INFO_CAPS))

		return NULL;



	if (cap_offset)

		VFIO_ASSERT_GE(cap_offset, sizeof(*info));



	max_depth = (info->argsz - sizeof(*info)) / sizeof(*hdr);



	while ((hdr = next_cap_hdr(info, info->argsz, &cap_offset))) {

		depth++;

		VFIO_ASSERT_LE(depth, max_depth, "Capability chain contains a cycle\n");



		if (hdr->id == cap_id)

			return hdr;

	}



	return NULL;

}



/* Return buffer including capability chain, if present. Free with free() */

static struct vfio_iommu_type1_info *vfio_iommu_get_info(struct vfio_pci_device *device)

{

	struct vfio_iommu_type1_info *info;



	info = malloc(sizeof(*info));

	VFIO_ASSERT_NOT_NULL(info);



	*info = (struct vfio_iommu_type1_info) {

		.argsz = sizeof(*info),

	};



	ioctl_assert(device->container_fd, VFIO_IOMMU_GET_INFO, info);

	VFIO_ASSERT_GE(info->argsz, sizeof(*info));



	info = realloc(info, info->argsz);

	VFIO_ASSERT_NOT_NULL(info);



	ioctl_assert(device->container_fd, VFIO_IOMMU_GET_INFO, info);

	VFIO_ASSERT_GE(info->argsz, sizeof(*info));



	return info;

}



/*

 * Return iova ranges for the device's container. Normalize vfio_iommu_type1 to

 * report iommufd's iommu_iova_range. Free with free().

 */

static struct iommu_iova_range *vfio_iommu_iova_ranges(struct vfio_pci_device *device,

						       u32 *nranges)

{

	struct vfio_iommu_type1_info_cap_iova_range *cap_range;

	struct vfio_iommu_type1_info *info;

	struct vfio_info_cap_header *hdr;

	struct iommu_iova_range *ranges = NULL;



	info = vfio_iommu_get_info(device);

	hdr = vfio_iommu_info_cap_hdr(info, VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE);

	VFIO_ASSERT_NOT_NULL(hdr);



	cap_range = container_of(hdr, struct vfio_iommu_type1_info_cap_iova_range, header);

	VFIO_ASSERT_GT(cap_range->nr_iovas, 0);



	ranges = calloc(cap_range->nr_iovas, sizeof(*ranges));

	VFIO_ASSERT_NOT_NULL(ranges);



	for (u32 i = 0; i < cap_range->nr_iovas; i++) {

		ranges[i] = (struct iommu_iova_range){

			.start = cap_range->iova_ranges[i].start,

			.last = cap_range->iova_ranges[i].end,

		};

	}



	*nranges = cap_range->nr_iovas;



	free(info);

	return ranges;

}



/* Return iova ranges of the device's IOAS. Free with free() */

static struct iommu_iova_range *iommufd_iova_ranges(struct vfio_pci_device *device,

						    u32 *nranges)

{

	struct iommu_iova_range *ranges;

	int ret;



	struct iommu_ioas_iova_ranges query = {

		.size = sizeof(query),

		.ioas_id = device->ioas_id,

	};



	ret = ioctl(device->iommufd, IOMMU_IOAS_IOVA_RANGES, &query);

	VFIO_ASSERT_EQ(ret, -1);

	VFIO_ASSERT_EQ(errno, EMSGSIZE);

	VFIO_ASSERT_GT(query.num_iovas, 0);



	ranges = calloc(query.num_iovas, sizeof(*ranges));

	VFIO_ASSERT_NOT_NULL(ranges);



	query.allowed_iovas = (uintptr_t)ranges;



	ioctl_assert(device->iommufd, IOMMU_IOAS_IOVA_RANGES, &query);

	*nranges = query.num_iovas;



	return ranges;

}



static int iova_range_comp(const void *a, const void *b)

{

	const struct iommu_iova_range *ra = a, *rb = b;



	if (ra->start < rb->start)

		return -1;



	if (ra->start > rb->start)

		return 1;



	return 0;

}



/* Return sorted IOVA ranges of the device. Free with free(). */

struct iommu_iova_range *vfio_pci_iova_ranges(struct vfio_pci_device *device,

					      u32 *nranges)

{

	struct iommu_iova_range *ranges;



	if (device->iommufd)

		ranges = iommufd_iova_ranges(device, nranges);

	else

		ranges = vfio_iommu_iova_ranges(device, nranges);



	if (!ranges)

		return NULL;



	VFIO_ASSERT_GT(*nranges, 0);



	/* Sort and check that ranges are sane and non-overlapping */

	qsort(ranges, *nranges, sizeof(*ranges), iova_range_comp);

	VFIO_ASSERT_LT(ranges[0].start, ranges[0].last);



	for (u32 i = 1; i < *nranges; i++) {

		VFIO_ASSERT_LT(ranges[i].start, ranges[i].last);

		VFIO_ASSERT_LT(ranges[i - 1].last, ranges[i].start);

	}



	return ranges;

}



iova_t __to_iova(struct vfio_pci_device *device, void *vaddr)

{

	struct vfio_dma_region *region;