vfio: selftests: fix map limit tests to use last available iova

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")
Reviewed-by: David Matlack <dmatlack@google.com>
Tested-by: David Matlack <dmatlack@google.com>
Signed-off-by: Alex Mastro <amastro@fb.com>
Link: https://lore.kernel.org/r/20251111-iova-ranges-v3-2-7960244642c5@fb.com
Signed-off-by: Alex Williamson <alex@shazbot.org>

diff --git a/tools/testing/selftests/vfio/vfio_dma_mapping_test.c b/tools/testing/selftests/vfio/vfio_dma_mapping_test.c
index 4f1ea79a200c688dea9823b8c5037571de4572a9..e1374aab96bd87db5e33dc90bd1d7688e8b4b595 100644 (file)
--- 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 <sys/mman.h>
 #include <unistd.h>
 
+#include <uapi/linux/types.h>
+#include <linux/iommufd.h>
 #include <linux/limits.h>
 #include <linux/mman.h>
 #include <linux/sizes.h>
@@ -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);