Since the memfd pages associated with a udmabuf may be migrated as part of udmabuf create, we need to verify the data coherency after successful migration. The new tests added in this patch try to do just that using 4k sized pages and also 2 MB sized huge pages for the memfd.
Successful completion of the tests would mean that there is no disconnect between the memfd pages and the ones associated with a udmabuf. And, these tests can also be augmented in the future to test newer udmabuf features (such as handling memfd hole punch).
The idea for these tests comes from a patch by Mike Kravetz here: https://lists.freedesktop.org/archives/dri-devel/2023-June/410623.html
v1->v2: (suggestions from Shuah) - Use ksft_* functions to print and capture results of tests - Use appropriate KSFT_* status codes for exit() - Add Mike Kravetz's suggested-by tag
Cc: Shuah Khan shuah@kernel.org Cc: David Hildenbrand david@redhat.com Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: Hugh Dickins hughd@google.com Cc: Peter Xu peterx@redhat.com Cc: Jason Gunthorpe jgg@nvidia.com Cc: Gerd Hoffmann kraxel@redhat.com Cc: Dongwon Kim dongwon.kim@intel.com Cc: Junxiao Chang junxiao.chang@intel.com Cc: linux-kselftest@vger.kernel.org Suggested-by: Mike Kravetz mike.kravetz@oracle.com Acked-by: Dave Airlie airlied@redhat.com Acked-by: Gerd Hoffmann kraxel@redhat.com Signed-off-by: Vivek Kasireddy vivek.kasireddy@intel.com --- .../selftests/drivers/dma-buf/udmabuf.c | 214 +++++++++++++++--- 1 file changed, 183 insertions(+), 31 deletions(-)
diff --git a/tools/testing/selftests/drivers/dma-buf/udmabuf.c b/tools/testing/selftests/drivers/dma-buf/udmabuf.c index c812080e304e..6062723a172e 100644 --- a/tools/testing/selftests/drivers/dma-buf/udmabuf.c +++ b/tools/testing/selftests/drivers/dma-buf/udmabuf.c @@ -9,52 +9,162 @@ #include <errno.h> #include <fcntl.h> #include <malloc.h> +#include <stdbool.h>
#include <sys/ioctl.h> #include <sys/syscall.h> +#include <sys/mman.h> #include <linux/memfd.h> #include <linux/udmabuf.h> +#include "../../kselftest.h"
#define TEST_PREFIX "drivers/dma-buf/udmabuf" #define NUM_PAGES 4 +#define NUM_ENTRIES 4 +#define MEMFD_SIZE 1024 /* in pages */
-static int memfd_create(const char *name, unsigned int flags) +static unsigned int page_size; + +static int create_memfd_with_seals(off64_t size, bool hpage) +{ + int memfd, ret; + unsigned int flags = MFD_ALLOW_SEALING; + + if (hpage) + flags |= MFD_HUGETLB; + + memfd = memfd_create("udmabuf-test", flags); + if (memfd < 0) { + ksft_print_msg("%s: [skip,no-memfd]\n", TEST_PREFIX); + exit(KSFT_SKIP); + } + + ret = fcntl(memfd, F_ADD_SEALS, F_SEAL_SHRINK); + if (ret < 0) { + ksft_print_msg("%s: [skip,fcntl-add-seals]\n", TEST_PREFIX); + exit(KSFT_SKIP); + } + + ret = ftruncate(memfd, size); + if (ret == -1) { + ksft_print_msg("%s: [FAIL,memfd-truncate]\n", TEST_PREFIX); + exit(KSFT_FAIL); + } + + return memfd; +} + +static int create_udmabuf_list(int devfd, int memfd, off64_t memfd_size) +{ + struct udmabuf_create_list *list; + int ubuf_fd, i; + + list = malloc(sizeof(struct udmabuf_create_list) + + sizeof(struct udmabuf_create_item) * NUM_ENTRIES); + if (!list) { + ksft_print_msg("%s: [FAIL, udmabuf-malloc]\n", TEST_PREFIX); + exit(KSFT_FAIL); + } + + for (i = 0; i < NUM_ENTRIES; i++) { + list->list[i].memfd = memfd; + list->list[i].offset = i * (memfd_size / NUM_ENTRIES); + list->list[i].size = getpagesize() * NUM_PAGES; + } + + list->count = NUM_ENTRIES; + list->flags = UDMABUF_FLAGS_CLOEXEC; + ubuf_fd = ioctl(devfd, UDMABUF_CREATE_LIST, list); + free(list); + if (ubuf_fd < 0) { + ksft_print_msg("%s: [FAIL, udmabuf-create]\n", TEST_PREFIX); + exit(KSFT_FAIL); + } + + return ubuf_fd; +} + +static void write_to_memfd(void *addr, off64_t size, char chr) +{ + int i; + + for (i = 0; i < size / page_size; i++) { + *((char *)addr + (i * page_size)) = chr; + } +} + +static void *mmap_fd(int fd, off64_t size) { - return syscall(__NR_memfd_create, name, flags); + void *addr; + + addr = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); + if (addr == MAP_FAILED) { + ksft_print_msg("%s: ubuf_fd mmap fail\n", TEST_PREFIX); + exit(KSFT_FAIL); + } + + return addr; +} + +static int compare_chunks(void *addr1, void *addr2, off64_t memfd_size) +{ + off64_t off; + int i = 0, j, k = 0, ret = 0; + char char1, char2; + + while (i < NUM_ENTRIES) { + off = i * (memfd_size / NUM_ENTRIES); + for (j = 0; j < NUM_PAGES; j++, k++) { + char1 = *((char *)addr1 + off + (j * getpagesize())); + char2 = *((char *)addr2 + (k * getpagesize())); + if (char1 != char2) { + ret = -1; + goto err; + } + } + i++; + } +err: + munmap(addr1, memfd_size); + munmap(addr2, NUM_ENTRIES * NUM_PAGES * getpagesize()); + return ret; }
int main(int argc, char *argv[]) { struct udmabuf_create create; int devfd, memfd, buf, ret; - off_t size; - void *mem; + off64_t size; + void *addr1, *addr2; + + ksft_print_header(); + ksft_set_plan(6);
devfd = open("/dev/udmabuf", O_RDWR); if (devfd < 0) { - printf("%s: [skip,no-udmabuf: Unable to access DMA buffer device file]\n", - TEST_PREFIX); - exit(77); + ksft_print_msg( + "%s: [skip,no-udmabuf: Unable to access DMA buffer device file]\n", + TEST_PREFIX); + exit(KSFT_SKIP); }
memfd = memfd_create("udmabuf-test", MFD_ALLOW_SEALING); if (memfd < 0) { - printf("%s: [skip,no-memfd]\n", TEST_PREFIX); - exit(77); + ksft_print_msg("%s: [skip,no-memfd]\n", TEST_PREFIX); + exit(KSFT_SKIP); }
ret = fcntl(memfd, F_ADD_SEALS, F_SEAL_SHRINK); if (ret < 0) { - printf("%s: [skip,fcntl-add-seals]\n", TEST_PREFIX); - exit(77); + ksft_print_msg("%s: [skip,fcntl-add-seals]\n", TEST_PREFIX); + exit(KSFT_SKIP); }
- size = getpagesize() * NUM_PAGES; ret = ftruncate(memfd, size); if (ret == -1) { - printf("%s: [FAIL,memfd-truncate]\n", TEST_PREFIX); - exit(1); + ksft_print_msg("%s: [FAIL,memfd-truncate]\n", TEST_PREFIX); + exit(KSFT_FAIL); }
memset(&create, 0, sizeof(create)); @@ -64,44 +174,86 @@ int main(int argc, char *argv[]) create.offset = getpagesize()/2; create.size = getpagesize(); buf = ioctl(devfd, UDMABUF_CREATE, &create); - if (buf >= 0) { - printf("%s: [FAIL,test-1]\n", TEST_PREFIX); - exit(1); - } + if (buf >= 0) + ksft_test_result_fail("%s: [FAIL,test-1]\n", TEST_PREFIX); + else + ksft_test_result_pass("%s: [PASS,test-1]\n", TEST_PREFIX);
/* should fail (size not multiple of page) */ create.memfd = memfd; create.offset = 0; create.size = getpagesize()/2; buf = ioctl(devfd, UDMABUF_CREATE, &create); - if (buf >= 0) { - printf("%s: [FAIL,test-2]\n", TEST_PREFIX); - exit(1); - } + if (buf >= 0) + ksft_test_result_fail("%s: [FAIL,test-2]\n", TEST_PREFIX); + else + ksft_test_result_pass("%s: [PASS,test-2]\n", TEST_PREFIX);
/* should fail (not memfd) */ create.memfd = 0; /* stdin */ create.offset = 0; create.size = size; buf = ioctl(devfd, UDMABUF_CREATE, &create); - if (buf >= 0) { - printf("%s: [FAIL,test-3]\n", TEST_PREFIX); - exit(1); - } + if (buf >= 0) + ksft_test_result_fail("%s: [FAIL,test-3]\n", TEST_PREFIX); + else + ksft_test_result_pass("%s: [PASS,test-3]\n", TEST_PREFIX);
/* should work */ + page_size = getpagesize(); + addr1 = mmap_fd(memfd, size); + write_to_memfd(addr1, size, 'a'); create.memfd = memfd; create.offset = 0; create.size = size; buf = ioctl(devfd, UDMABUF_CREATE, &create); - if (buf < 0) { - printf("%s: [FAIL,test-4]\n", TEST_PREFIX); - exit(1); - } + if (buf < 0) + ksft_test_result_fail("%s: [FAIL,test-4]\n", TEST_PREFIX); + else + ksft_test_result_pass("%s: [PASS,test-4]\n", TEST_PREFIX); + + munmap(addr1, size); + close(buf); + close(memfd); + + /* should work (migration of 4k size pages)*/ + size = MEMFD_SIZE * page_size; + memfd = create_memfd_with_seals(size, false); + addr1 = mmap_fd(memfd, size); + write_to_memfd(addr1, size, 'a'); + buf = create_udmabuf_list(devfd, memfd, size); + addr2 = mmap_fd(buf, NUM_PAGES * NUM_ENTRIES * getpagesize()); + write_to_memfd(addr1, size, 'b'); + ret = compare_chunks(addr1, addr2, size); + if (ret < 0) + ksft_test_result_fail("%s: [FAIL,test-5]\n", TEST_PREFIX); + else + ksft_test_result_pass("%s: [PASS,test-5]\n", TEST_PREFIX); + + close(buf); + close(memfd); + + /* should work (migration of 2MB size huge pages)*/ + page_size = getpagesize() * 512; /* 2 MB */ + size = MEMFD_SIZE * page_size; + memfd = create_memfd_with_seals(size, true); + addr1 = mmap_fd(memfd, size); + write_to_memfd(addr1, size, 'a'); + buf = create_udmabuf_list(devfd, memfd, size); + addr2 = mmap_fd(buf, NUM_PAGES * NUM_ENTRIES * getpagesize()); + write_to_memfd(addr1, size, 'b'); + ret = compare_chunks(addr1, addr2, size); + if (ret < 0) + ksft_test_result_fail("%s: [FAIL,test-6]\n", TEST_PREFIX); + else + ksft_test_result_pass("%s: [PASS,test-6]\n", TEST_PREFIX);
- fprintf(stderr, "%s: ok\n", TEST_PREFIX); close(buf); close(memfd); close(devfd); + + ksft_print_msg("%s: ok\n", TEST_PREFIX); + ksft_print_cnts(); + return 0; }