On Mon, Nov 10, 2025 at 02:31:54PM -0700, Alex Williamson wrote:
On Mon, 10 Nov 2025 13:10:43 -0800 Alex Mastro amastro@fb.com wrote:
Add struct iova_allocator, which gives tests a convenient way to generate legally-accessible IOVAs to map.
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 amastro@fb.com
.../testing/selftests/vfio/lib/include/vfio_util.h | 14 +++++ tools/testing/selftests/vfio/lib/vfio_pci_device.c | 65 +++++++++++++++++++++- 2 files changed, 78 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 fb5efec52316..bb1e7d39dfb9 100644 --- a/tools/testing/selftests/vfio/lib/include/vfio_util.h +++ b/tools/testing/selftests/vfio/lib/include/vfio_util.h @@ -13,6 +13,8 @@ #include "../../../kselftest.h" +#define ALIGN(x, a) (((x) + (a - 1)) & (~((a) - 1)))
#define VFIO_LOG_AND_EXIT(...) do { \ fprintf(stderr, " " __VA_ARGS__); \ fprintf(stderr, "\n"); \ @@ -188,6 +190,13 @@ struct vfio_pci_device { struct vfio_pci_driver driver; }; +struct iova_allocator {
- struct iommu_iova_range *ranges;
- size_t nranges;
- size_t range_idx;
- iova_t iova_next;
+};
/*
- Return the BDF string of the device that the test should use.
@@ -212,6 +221,11 @@ void vfio_pci_device_reset(struct vfio_pci_device *device); struct iommu_iova_range *vfio_pci_iova_ranges(struct vfio_pci_device *device, size_t *nranges); +int iova_allocator_init(struct vfio_pci_device *device,
struct iova_allocator *allocator);+void iova_allocator_deinit(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 6bedbe65f0a1..a634feb1d378 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 <sys/mman.h> #include <uapi/linux/types.h> +#include <linux/iommufd.h> #include <linux/limits.h> #include <linux/mman.h> +#include <linux/overflow.h> #include <linux/types.h> #include <linux/vfio.h> -#include <linux/iommufd.h> #include "../../../kselftest.h" #include <vfio_util.h> @@ -190,6 +191,68 @@ struct iommu_iova_range *vfio_pci_iova_ranges(struct vfio_pci_device *device, return ranges; } +int iova_allocator_init(struct vfio_pci_device *device,
struct iova_allocator *allocator)+{
- struct iommu_iova_range *ranges;
- size_t nranges;
- memset(allocator, 0, sizeof(*allocator));
- ranges = vfio_pci_iova_ranges(device, &nranges);
- if (!ranges)
return -ENOENT;- *allocator = (struct iova_allocator){
.ranges = ranges,.nranges = nranges,.range_idx = 0,.iova_next = 0,iova_next needs to be initialized from ranges[0].start. Thanks,
True. Thanks for catching this.
Alex
- };
- return 0;
+}
+void iova_allocator_deinit(struct iova_allocator *allocator) +{
- free(allocator->ranges);
+}
+iova_t iova_allocator_alloc(struct iova_allocator *allocator, size_t size) +{
- int idx = allocator->range_idx;
- struct iommu_iova_range *range = &allocator->ranges[idx];
- VFIO_ASSERT_LT(idx, allocator->nranges, "IOVA allocator out of space\n");
- 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 (;;) {
iova_t iova, last;iova = ALIGN(allocator->iova_next, size);if (iova < allocator->iova_next || iova > range->last ||check_add_overflow(iova, size - 1, &last) ||last > range->last) {allocator->range_idx = ++idx;VFIO_ASSERT_LT(idx, allocator->nranges,"Out of ranges for allocation\n");allocator->iova_next = (++range)->start;continue;}if (check_add_overflow(last, (iova_t)1, &allocator->iova_next) ||allocator->iova_next > range->last) {allocator->range_idx = ++idx;if (idx < allocator->nranges)allocator->iova_next = (++range)->start;}return iova;- }
+}
iova_t __to_iova(struct vfio_pci_device *device, void *vaddr) { struct vfio_dma_region *region;