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

Mike Rapoport
2023-04-11T11:10:53Z

On Thu, Mar 30, 2023 at 12:08:18PM -0400, Peter Xu wrote:
> 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");

Maybe uffd_test_skip("environment setup 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
>

--
Sincerely yours,
Mike.