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. Signed-off-by: Alex Mastro --- .../testing/selftests/vfio/lib/include/vfio_util.h | 8 +- tools/testing/selftests/vfio/lib/vfio_pci_device.c | 167 +++++++++++++++++++++ 2 files changed, 174 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/vfio/lib/include/vfio_util.h b/tools/testing/selftests/vfio/lib/include/vfio_util.h index 240409bf5f8a..ef8f06ef0c13 100644 --- a/tools/testing/selftests/vfio/lib/include/vfio_util.h +++ b/tools/testing/selftests/vfio/lib/include/vfio_util.h @@ -4,9 +4,12 @@ #include #include -#include + +#include +#include #include #include +#include #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, diff --git a/tools/testing/selftests/vfio/lib/vfio_pci_device.c b/tools/testing/selftests/vfio/lib/vfio_pci_device.c index a381fd253aa7..7a523e3f2dce 100644 --- a/tools/testing/selftests/vfio/lib/vfio_pci_device.c +++ b/tools/testing/selftests/vfio/lib/vfio_pci_device.c @@ -29,6 +29,173 @@ 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, size_t bufsz, + size_t *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); + + if (hdr->next) + VFIO_ASSERT_GT(hdr->next, *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; + size_t cap_offset = info->cap_offset; + + if (!(info->flags & VFIO_IOMMU_INFO_CAPS)) + return NULL; + + if (cap_offset) + VFIO_ASSERT_GE(cap_offset, sizeof(struct vfio_iommu_type1_info)); + + while ((hdr = next_cap_hdr(info, info->argsz, &cap_offset))) { + 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); + + info = realloc(info, info->argsz); + VFIO_ASSERT_NOT_NULL(info); + + ioctl_assert(device->container_fd, VFIO_IOMMU_GET_INFO, 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; -- 2.47.3 Use the newly available vfio_pci_iova_ranges() to determine the last legal IOVA, and use this as the basis for vfio_dma_map_limit_test tests. Fixes: de8d1f2fd5a5 ("vfio: selftests: add end of address space DMA map/unmap tests") Signed-off-by: Alex Mastro --- tools/testing/selftests/vfio/vfio_dma_mapping_test.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/vfio/vfio_dma_mapping_test.c b/tools/testing/selftests/vfio/vfio_dma_mapping_test.c index 4f1ea79a200c..e1374aab96bd 100644 --- a/tools/testing/selftests/vfio/vfio_dma_mapping_test.c +++ b/tools/testing/selftests/vfio/vfio_dma_mapping_test.c @@ -3,6 +3,8 @@ #include #include +#include +#include #include #include #include @@ -219,7 +221,10 @@ FIXTURE_VARIANT_ADD_ALL_IOMMU_MODES(); FIXTURE_SETUP(vfio_dma_map_limit_test) { struct vfio_dma_region *region = &self->region; + struct iommu_iova_range *ranges; u64 region_size = getpagesize(); + iova_t last_iova; + u32 nranges; /* * Over-allocate mmap by double the size to provide enough backing vaddr @@ -232,8 +237,13 @@ FIXTURE_SETUP(vfio_dma_map_limit_test) MAP_ANONYMOUS | MAP_PRIVATE, -1, 0); ASSERT_NE(region->vaddr, MAP_FAILED); - /* One page prior to the end of address space */ - region->iova = ~(iova_t)0 & ~(region_size - 1); + ranges = vfio_pci_iova_ranges(self->device, &nranges); + VFIO_ASSERT_NOT_NULL(ranges); + last_iova = ranges[nranges - 1].last; + free(ranges); + + /* One page prior to the last iova */ + region->iova = last_iova & ~(region_size - 1); region->size = region_size; } @@ -276,6 +286,7 @@ TEST_F(vfio_dma_map_limit_test, overflow) struct vfio_dma_region *region = &self->region; int rc; + region->iova = ~(iova_t)0 & ~(region->size - 1); region->size = self->mmap_size; rc = __vfio_pci_dma_map(self->device, region); -- 2.47.3 Add struct iova_allocator, which gives tests a convenient way to generate legally-accessible IOVAs to map. This allocator traverses the sorted available IOVA ranges linearly, requires power-of-two size allocations, and does not support freeing iova allocations. The assumption is that tests are not IOVA space-bounded, and will not need to recycle IOVAs. This is based on Alex Williamson's patch series for adding an IOVA allocator [1]. [1] https://lore.kernel.org/all/20251108212954.26477-1-alex@shazbot.org/ Signed-off-by: Alex Mastro --- The unfolded code uses David's range_offset suggestion because it makes assignment of the updated state simpler when crossing a range boundary. No more ALIGN(). The insight is that the initial check for sufficient space (pre-alignment) requires computing last = iova + size - 1 which is already half of what ALIGN() does. Just masking is left. --- --- .../testing/selftests/vfio/lib/include/vfio_util.h | 11 ++++ tools/testing/selftests/vfio/lib/vfio_pci_device.c | 74 +++++++++++++++++++++- 2 files changed, 84 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/vfio/lib/include/vfio_util.h b/tools/testing/selftests/vfio/lib/include/vfio_util.h index ef8f06ef0c13..69ec0c856481 100644 --- a/tools/testing/selftests/vfio/lib/include/vfio_util.h +++ b/tools/testing/selftests/vfio/lib/include/vfio_util.h @@ -188,6 +188,13 @@ struct vfio_pci_device { struct vfio_pci_driver driver; }; +struct iova_allocator { + struct iommu_iova_range *ranges; + u32 nranges; + u32 range_idx; + u64 range_offset; +}; + /* * Return the BDF string of the device that the test should use. * @@ -212,6 +219,10 @@ 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); +struct iova_allocator *iova_allocator_init(struct vfio_pci_device *device); +void iova_allocator_cleanup(struct iova_allocator *allocator); +iova_t iova_allocator_alloc(struct iova_allocator *allocator, size_t size); + 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, diff --git a/tools/testing/selftests/vfio/lib/vfio_pci_device.c b/tools/testing/selftests/vfio/lib/vfio_pci_device.c index 7a523e3f2dce..ff1edb11747a 100644 --- a/tools/testing/selftests/vfio/lib/vfio_pci_device.c +++ b/tools/testing/selftests/vfio/lib/vfio_pci_device.c @@ -12,11 +12,12 @@ #include #include +#include #include #include +#include #include #include -#include #include "../../../kselftest.h" #include @@ -196,6 +197,77 @@ struct iommu_iova_range *vfio_pci_iova_ranges(struct vfio_pci_device *device, return ranges; } +struct iova_allocator *iova_allocator_init(struct vfio_pci_device *device) +{ + struct iova_allocator *allocator; + struct iommu_iova_range *ranges; + u32 nranges; + + ranges = vfio_pci_iova_ranges(device, &nranges); + VFIO_ASSERT_NOT_NULL(ranges); + + allocator = malloc(sizeof(*allocator)); + VFIO_ASSERT_NOT_NULL(allocator); + + *allocator = (struct iova_allocator){ + .ranges = ranges, + .nranges = nranges, + .range_idx = 0, + .range_offset = 0, + }; + + return allocator; +} + +void iova_allocator_cleanup(struct iova_allocator *allocator) +{ + free(allocator->ranges); + free(allocator); +} + +iova_t iova_allocator_alloc(struct iova_allocator *allocator, size_t size) +{ + VFIO_ASSERT_GT(size, 0, "Invalid size arg, zero\n"); + VFIO_ASSERT_EQ(size & (size - 1), 0, "Invalid size arg, non-power-of-2\n"); + + for (;;) { + struct iommu_iova_range *range; + iova_t iova, last; + + VFIO_ASSERT_LT(allocator->range_idx, allocator->nranges, + "IOVA allocator out of space\n"); + + range = &allocator->ranges[allocator->range_idx]; + iova = range->start + allocator->range_offset; + + /* Check for sufficient space at the current offset */ + if (check_add_overflow(iova, size - 1, &last) || + last > range->last) + goto next_range; + + /* Align iova to size */ + iova = last & ~(size - 1); + + /* Check for sufficient space at the aligned iova */ + if (check_add_overflow(iova, size - 1, &last) || + last > range->last) + goto next_range; + + if (last == range->last) { + allocator->range_idx++; + allocator->range_offset = 0; + } else { + allocator->range_offset = last - range->start + 1; + } + + return iova; + +next_range: + allocator->range_idx++; + allocator->range_offset = 0; + } +} + iova_t __to_iova(struct vfio_pci_device *device, void *vaddr) { struct vfio_dma_region *region; -- 2.47.3 vfio_dma_mapping_test and vfio_pci_driver_test currently use iova=vaddr as part of DMA mapping operations. The assumption that these IOVAs are legal has held up on all the hardware we've tested so far, but is not guaranteed. Make the tests more robust by using iova_allocator to vend IOVAs, which queries legally accessible IOVAs from the underlying IOMMUFD or VFIO container. Signed-off-by: Alex Mastro --- tools/testing/selftests/vfio/vfio_dma_mapping_test.c | 5 ++++- tools/testing/selftests/vfio/vfio_pci_driver_test.c | 12 ++++++++---- 2 files changed, 12 insertions(+), 5 deletions(-) diff --git a/tools/testing/selftests/vfio/vfio_dma_mapping_test.c b/tools/testing/selftests/vfio/vfio_dma_mapping_test.c index e1374aab96bd..102603d4407d 100644 --- a/tools/testing/selftests/vfio/vfio_dma_mapping_test.c +++ b/tools/testing/selftests/vfio/vfio_dma_mapping_test.c @@ -95,6 +95,7 @@ static int iommu_mapping_get(const char *bdf, u64 iova, FIXTURE(vfio_dma_mapping_test) { struct vfio_pci_device *device; + struct iova_allocator *iova_allocator; }; FIXTURE_VARIANT(vfio_dma_mapping_test) { @@ -119,10 +120,12 @@ FIXTURE_VARIANT_ADD_ALL_IOMMU_MODES(anonymous_hugetlb_1gb, SZ_1G, MAP_HUGETLB | FIXTURE_SETUP(vfio_dma_mapping_test) { self->device = vfio_pci_device_init(device_bdf, variant->iommu_mode); + self->iova_allocator = iova_allocator_init(self->device); } FIXTURE_TEARDOWN(vfio_dma_mapping_test) { + iova_allocator_cleanup(self->iova_allocator); vfio_pci_device_cleanup(self->device); } @@ -144,7 +147,7 @@ TEST_F(vfio_dma_mapping_test, dma_map_unmap) else ASSERT_NE(region.vaddr, MAP_FAILED); - region.iova = (u64)region.vaddr; + region.iova = iova_allocator_alloc(self->iova_allocator, size); region.size = size; vfio_pci_dma_map(self->device, ®ion); diff --git a/tools/testing/selftests/vfio/vfio_pci_driver_test.c b/tools/testing/selftests/vfio/vfio_pci_driver_test.c index 2dbd70b7db62..f69eec8b928d 100644 --- a/tools/testing/selftests/vfio/vfio_pci_driver_test.c +++ b/tools/testing/selftests/vfio/vfio_pci_driver_test.c @@ -19,6 +19,7 @@ static const char *device_bdf; } while (0) static void region_setup(struct vfio_pci_device *device, + struct iova_allocator *iova_allocator, struct vfio_dma_region *region, u64 size) { const int flags = MAP_SHARED | MAP_ANONYMOUS; @@ -29,7 +30,7 @@ static void region_setup(struct vfio_pci_device *device, VFIO_ASSERT_NE(vaddr, MAP_FAILED); region->vaddr = vaddr; - region->iova = (u64)vaddr; + region->iova = iova_allocator_alloc(iova_allocator, size); region->size = size; vfio_pci_dma_map(device, region); @@ -44,6 +45,7 @@ static void region_teardown(struct vfio_pci_device *device, FIXTURE(vfio_pci_driver_test) { struct vfio_pci_device *device; + struct iova_allocator *iova_allocator; struct vfio_dma_region memcpy_region; void *vaddr; int msi_fd; @@ -72,14 +74,15 @@ FIXTURE_SETUP(vfio_pci_driver_test) struct vfio_pci_driver *driver; self->device = vfio_pci_device_init(device_bdf, variant->iommu_mode); + self->iova_allocator = iova_allocator_init(self->device); driver = &self->device->driver; - region_setup(self->device, &self->memcpy_region, SZ_1G); - region_setup(self->device, &driver->region, SZ_2M); + region_setup(self->device, self->iova_allocator, &self->memcpy_region, SZ_1G); + region_setup(self->device, self->iova_allocator, &driver->region, SZ_2M); /* Any IOVA that doesn't overlap memcpy_region and driver->region. */ - self->unmapped_iova = 8UL * SZ_1G; + self->unmapped_iova = iova_allocator_alloc(self->iova_allocator, SZ_1G); vfio_pci_driver_init(self->device); self->msi_fd = self->device->msi_eventfds[driver->msi]; @@ -108,6 +111,7 @@ FIXTURE_TEARDOWN(vfio_pci_driver_test) region_teardown(self->device, &self->memcpy_region); region_teardown(self->device, &driver->region); + iova_allocator_cleanup(self->iova_allocator); vfio_pci_device_cleanup(self->device); } -- 2.47.3