From: Josh Hilke jrhilke@google.com
Update vfio dma mapping test to verify that the IOMMU uses 2M and 1G mappings when 2M and 1G HugeTLB pages are mapped into a device respectively.
This validation is done by inspecting the contents of the I/O page tables via /sys/kernel/debug/iommu/intel/. This validation is skipped if that directory is not available (i.e. non-Intel IOMMUs).
Signed-off-by: Josh Hilke jrhilke@google.com [reword commit message, refactor code] Acked-by: Shuah Khan skhan@linuxfoundation.org Signed-off-by: David Matlack dmatlack@google.com --- .../selftests/vfio/vfio_dma_mapping_test.c | 111 ++++++++++++++++++ 1 file changed, 111 insertions(+)
diff --git a/tools/testing/selftests/vfio/vfio_dma_mapping_test.c b/tools/testing/selftests/vfio/vfio_dma_mapping_test.c index 8f8e6e9e8197..2612f0cabea5 100644 --- a/tools/testing/selftests/vfio/vfio_dma_mapping_test.c +++ b/tools/testing/selftests/vfio/vfio_dma_mapping_test.c @@ -14,6 +14,83 @@
static const char *device_bdf;
+struct iommu_mapping { + u64 pgd; + u64 p4d; + u64 pud; + u64 pmd; + u64 pte; +}; + +static void parse_next_value(char **line, u64 *value) +{ + char *token; + + token = strtok_r(*line, " \t|\n", line); + if (!token) + return; + + /* Caller verifies `value`. No need to check return value. */ + sscanf(token, "0x%lx", value); +} + +static int intel_iommu_mapping_get(const char *bdf, u64 iova, + struct iommu_mapping *mapping) +{ + char iommu_mapping_path[PATH_MAX], line[PATH_MAX]; + u64 line_iova = -1; + int ret = -ENOENT; + FILE *file; + char *rest; + + snprintf(iommu_mapping_path, sizeof(iommu_mapping_path), + "/sys/kernel/debug/iommu/intel/%s/domain_translation_struct", + bdf); + + printf("Searching for IOVA 0x%lx in %s\n", iova, iommu_mapping_path); + + file = fopen(iommu_mapping_path, "r"); + VFIO_ASSERT_NOT_NULL(file, "fopen(%s) failed", iommu_mapping_path); + + while (fgets(line, sizeof(line), file)) { + rest = line; + + parse_next_value(&rest, &line_iova); + if (line_iova != (iova / getpagesize())) + continue; + + /* + * Ensure each struct field is initialized in case of empty + * page table values. + */ + memset(mapping, 0, sizeof(*mapping)); + parse_next_value(&rest, &mapping->pgd); + parse_next_value(&rest, &mapping->p4d); + parse_next_value(&rest, &mapping->pud); + parse_next_value(&rest, &mapping->pmd); + parse_next_value(&rest, &mapping->pte); + + ret = 0; + break; + } + + fclose(file); + + if (ret) + printf("IOVA not found\n"); + + return ret; +} + +static int iommu_mapping_get(const char *bdf, u64 iova, + struct iommu_mapping *mapping) +{ + if (!access("/sys/kernel/debug/iommu/intel", F_OK)) + return intel_iommu_mapping_get(bdf, iova, mapping); + + return -EOPNOTSUPP; +} + FIXTURE(vfio_dma_mapping_test) { struct vfio_pci_device *device; }; @@ -51,8 +128,10 @@ TEST_F(vfio_dma_mapping_test, dma_map_unmap) { const u64 size = variant->size ?: getpagesize(); const int flags = variant->mmap_flags; + struct iommu_mapping mapping; void *mem; u64 iova; + int rc;
mem = mmap(NULL, size, PROT_READ | PROT_WRITE, flags, -1, 0);
@@ -67,7 +146,39 @@ TEST_F(vfio_dma_mapping_test, dma_map_unmap) vfio_pci_dma_map(self->device, iova, size, mem); printf("Mapped HVA %p (size 0x%lx) at IOVA 0x%lx\n", mem, size, iova);
+ rc = iommu_mapping_get(device_bdf, iova, &mapping); + if (rc == -EOPNOTSUPP) + goto unmap; + + ASSERT_EQ(0, rc); + printf("Found IOMMU mappings for IOVA 0x%lx:\n", iova); + printf("PGD: 0x%016lx\n", mapping.pgd); + printf("P4D: 0x%016lx\n", mapping.p4d); + printf("PUD: 0x%016lx\n", mapping.pud); + printf("PMD: 0x%016lx\n", mapping.pmd); + printf("PTE: 0x%016lx\n", mapping.pte); + + switch (size) { + case SZ_4K: + ASSERT_NE(0, mapping.pte); + break; + case SZ_2M: + ASSERT_EQ(0, mapping.pte); + ASSERT_NE(0, mapping.pmd); + break; + case SZ_1G: + ASSERT_EQ(0, mapping.pte); + ASSERT_EQ(0, mapping.pmd); + ASSERT_NE(0, mapping.pud); + break; + default: + VFIO_FAIL("Unrecognized size: 0x%lx\n", size); + } + +unmap: vfio_pci_dma_unmap(self->device, iova, size); + printf("Unmapped IOVA 0x%lx\n", iova); + ASSERT_NE(0, iommu_mapping_get(device_bdf, iova, &mapping));
ASSERT_TRUE(!munmap(mem, size)); }