[PATCH 21/29] selftests/mm: Add framework for uffd-unit-test

Peter Xu
2023-03-30T16:10:29Z

Add a framework to be prepared to move unit tests from uffd-stress.c into
uffd-unit-tests.c. The goal is to allow detection of uffd features for
each test, and also loop over specified types of memory that a test support.

Signed-off-by: Peter Xu <peterx@redhat.com>
---
tools/testing/selftests/mm/uffd-unit-tests.c | 125 +++++++++++++++++++
tools/testing/selftests/mm/vm_util.c | 27 ++++
tools/testing/selftests/mm/vm_util.h | 1 +
3 files changed, 153 insertions(+)

diff --git a/tools/testing/selftests/mm/uffd-unit-tests.c b/tools/testing/selftests/mm/uffd-unit-tests.c
index dfb44ffad5f5..007145063363 100644
--- a/tools/testing/selftests/mm/uffd-unit-tests.c
+++ b/tools/testing/selftests/mm/uffd-unit-tests.c
@@ -9,6 +9,66 @@

#ifdef __NR_userfaultfd

+/* The unit test doesn't need a large or random size, make it 32MB for now */
+#define UFFD_TEST_MEM_SIZE (32UL << 20)
+
+#define MEM_ANON BIT_ULL(0)
+#define MEM_SHMEM BIT_ULL(1)
+#define MEM_SHMEM_PRIVATE BIT_ULL(2)
+#define MEM_HUGETLB BIT_ULL(3)
+#define MEM_HUGETLB_PRIVATE BIT_ULL(4)
+
+struct mem_type {
+ const char *name;
+ unsigned int mem_flag;
+ uffd_test_ops_t *mem_ops;
+ bool shared;
+};
+typedef struct mem_type mem_type_t;
+
+mem_type_t mem_types[] = {
+ {
+ .name = "anon",
+ .mem_flag = MEM_ANON,
+ .mem_ops = &anon_uffd_test_ops,
+ .shared = false,
+ },
+ {
+ .name = "shmem",
+ .mem_flag = MEM_SHMEM,
+ .mem_ops = &shmem_uffd_test_ops,
+ .shared = true,
+ },
+ {
+ .name = "shmem-private",
+ .mem_flag = MEM_SHMEM_PRIVATE,
+ .mem_ops = &shmem_uffd_test_ops,
+ .shared = false,
+ },
+ {
+ .name = "hugetlb",
+ .mem_flag = MEM_HUGETLB,
+ .mem_ops = &hugetlb_uffd_test_ops,
+ .shared = true,
+ },
+ {
+ .name = "hugetlb-private",
+ .mem_flag = MEM_HUGETLB_PRIVATE,
+ .mem_ops = &hugetlb_uffd_test_ops,
+ .shared = false,
+ },
+};
+
+/* Returns: UFFD_TEST_* */
+typedef void (*uffd_test_fn)(void);
+
+typedef struct {
+ const char *name;
+ uffd_test_fn uffd_fn;
+ unsigned int mem_targets;
+ uint64_t uffd_feature_required;
+} uffd_test_case_t;
+
struct {
unsigned int pass, skip, fail, total;
} uffd_test_acct;
@@ -108,9 +168,50 @@ static int test_uffd_api(bool use_dev)
return 1;
}

+/*
+ * This function initializes the global variables. TODO: remove global
+ * vars and then remove this.
+ */
+static int uffd_setup_environment(uffd_test_case_t *test, mem_type_t *mem_type)
+{
+ map_shared = mem_type->shared;
+ uffd_test_ops = mem_type->mem_ops;
+
+ if (mem_type->mem_flag & (MEM_HUGETLB_PRIVATE | MEM_HUGETLB))
+ page_size = default_huge_page_size();
+ else
+ page_size = psize();
+
+ nr_pages = UFFD_TEST_MEM_SIZE / page_size;
+ /* TODO: remove this global var.. it's so ugly */
+ nr_cpus = 1;
+
+ return uffd_test_ctx_init(test->uffd_feature_required);
+}
+
+static bool uffd_feature_supported(uffd_test_case_t *test)
+{
+ uint64_t features;
+
+ if (uffd_get_features(&features))
+ return false;
+
+ return (features & test->uffd_feature_required) ==
+ test->uffd_feature_required;
+}
+
+uffd_test_case_t uffd_tests[] = {
+};
+
int main(int argc, char *argv[])
{
+ int n_tests = sizeof(uffd_tests) / sizeof(uffd_test_case_t);
+ int n_mems = sizeof(mem_types) / sizeof(mem_type_t);
+ uffd_test_case_t *test;
+ mem_type_t *mem_type;
+ char test_name[128];
int has_uffd;
+ int i, j;

has_uffd = test_uffd_api(false);
has_uffd |= test_uffd_api(true);
@@ -119,7 +220,31 @@ int main(int argc, char *argv[])
printf("Userfaultfd not supported or unprivileged, skip all tests\n");
exit(KSFT_SKIP);
}
+
+ for (i = 0; i < n_tests; i++) {
+ test = &uffd_tests[i];
+ for (j = 0; j < n_mems; j++) {
+ mem_type = &mem_types[j];
+ if (!(test->mem_targets & mem_type->mem_flag))
+ continue;
+ snprintf(test_name, sizeof(test_name),
+ "%s on %s", test->name, mem_type->name);
+
+ uffd_test_start(test_name);
+ if (!uffd_feature_supported(test)) {
+ uffd_test_skip("feature missing");
+ continue;
+ }
+ if (uffd_setup_environment(test, mem_type)) {
+ uffd_test_skip("memory allocation failed");
+ continue;
+ }
+ test->uffd_fn();
+ }
+ }
+
uffd_test_report();
+
return uffd_test_acct.fail ? KSFT_FAIL : KSFT_PASS;
}

diff --git a/tools/testing/selftests/mm/vm_util.c b/tools/testing/selftests/mm/vm_util.c
index 62fcf039d6b7..dad1f62a7ecd 100644
--- a/tools/testing/selftests/mm/vm_util.c
+++ b/tools/testing/selftests/mm/vm_util.c
@@ -264,3 +264,30 @@ int uffd_open(unsigned int flags)

return uffd;
}
+
+int uffd_get_features(uint64_t *features)
+{
+ struct uffdio_api uffdio_api = { .api = UFFD_API, .features = 0 };
+ /*
+ * This should by default work in most kernels; the feature list
+ * will be the same no matter what we pass in here.
+ */
+ int fd = uffd_open(UFFD_USER_MODE_ONLY);
+
+ if (fd < 0)
+ /* Maybe the kernel is older than user-only mode? */
+ fd = uffd_open(0);
+
+ if (fd < 0)
+ return fd;
+
+ if (ioctl(fd, UFFDIO_API, &uffdio_api)) {
+ close(fd);
+ return -errno;
+ }
+
+ *features = uffdio_api.features;
+ close(fd);
+
+ return 0;
+}
diff --git a/tools/testing/selftests/mm/vm_util.h b/tools/testing/selftests/mm/vm_util.h
index a67db8432855..2edad3256271 100644
--- a/tools/testing/selftests/mm/vm_util.h
+++ b/tools/testing/selftests/mm/vm_util.h
@@ -51,6 +51,7 @@ int uffd_open(unsigned int flags);
int uffd_register(int uffd, void *addr, uint64_t len,
bool miss, bool wp, bool minor);
int uffd_unregister(int uffd, void *addr, uint64_t len);
+int uffd_get_features(uint64_t *features);

/*
* On ppc64 this will only work with radix 2M hugepage size
--
2.39.1