From: Josh Hilke <jrhi...@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 <jrhi...@google.com>
[reword commit message, refactor code]
Signed-off-by: David Matlack <dmatl...@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 97bbe031b10d..9cdf25b293c5 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;
const u64 iova = 0;
void *mem;
+ int rc;
mem = mmap(NULL, size, PROT_READ | PROT_WRITE, flags, -1, 0);
@@ -65,7 +144,39 @@ 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));
}
--
2.50.0.rc2.701.gf1e915cc24-goog
