[PATCH v13 8/8] selftests/udmabuf: Add tests to verify data after page migration
Shuah Khan
skhan at linuxfoundation.org
Thu Apr 4 20:53:37 UTC 2024
On 4/4/24 01:26, Vivek Kasireddy wrote:
> 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.
Add Suggested-by for Mike Kravetz
>
> Cc: Shuah Khan <shuah at kernel.org>
> Cc: David Hildenbrand <david at redhat.com>
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> Cc: Mike Kravetz <mike.kravetz at oracle.com>
> Cc: Hugh Dickins <hughd at google.com>
> Cc: Peter Xu <peterx at redhat.com>
> Cc: Jason Gunthorpe <jgg at nvidia.com>
> Cc: Gerd Hoffmann <kraxel at redhat.com>
> Cc: Dongwon Kim <dongwon.kim at intel.com>
> Cc: Junxiao Chang <junxiao.chang at intel.com>
> Signed-off-by: Vivek Kasireddy <vivek.kasireddy at intel.com>
> ---
> .../selftests/drivers/dma-buf/udmabuf.c | 151 +++++++++++++++++-
> 1 file changed, 147 insertions(+), 4 deletions(-)
>
> diff --git a/tools/testing/selftests/drivers/dma-buf/udmabuf.c b/tools/testing/selftests/drivers/dma-buf/udmabuf.c
> index c812080e304e..d76c813fe652 100644
> --- a/tools/testing/selftests/drivers/dma-buf/udmabuf.c
> +++ b/tools/testing/selftests/drivers/dma-buf/udmabuf.c
> @@ -9,26 +9,132 @@
> #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>
>
> #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) {
> + printf("%s: [skip,no-memfd]\n", TEST_PREFIX);
> + exit(77);
> + }
> +
> + ret = fcntl(memfd, F_ADD_SEALS, F_SEAL_SHRINK);
> + if (ret < 0) {
> + printf("%s: [skip,fcntl-add-seals]\n", TEST_PREFIX);
Use the kselftest skip code here. Also use kselftest_* functions
to print results and exit messages for KTAP format.
> + exit(77);
This should be KSFT_SKIP
> + }
> +
> + ret = ftruncate(memfd, size);
> + if (ret == -1) {
> + printf("%s: [FAIL,memfd-truncate]\n", TEST_PREFIX);
> + exit(1);
Use 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) {
> + printf("%s: [FAIL, udmabuf-malloc]\n", TEST_PREFIX);
> + exit(1);
> + }
> +
> + 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) {
> + printf("%s: [FAIL, udmabuf-create]\n", TEST_PREFIX);
> + exit(1);
Same as before.
> + }
> +
> + 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) {
> + printf("%s: ubuf_fd mmap fail\n", TEST_PREFIX);
> + exit(1);
> + }
> +
> + 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;
>
> devfd = open("/dev/udmabuf", O_RDWR);
> if (devfd < 0) {
> @@ -90,6 +196,9 @@ int main(int argc, char *argv[])
> }
>
> /* 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;
> @@ -98,6 +207,40 @@ int main(int argc, char *argv[])
> printf("%s: [FAIL,test-4]\n", TEST_PREFIX);
> exit(1);
> }
> + 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) {
> + printf("%s: [FAIL,test-5]\n", TEST_PREFIX);
> + exit(1);
> + }
> + 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) {
> + printf("%s: [FAIL,test-6]\n", TEST_PREFIX);
> + exit(1);
> + }
>
> fprintf(stderr, "%s: ok\n", TEST_PREFIX);
> close(buf);
CC linux0kselftest list when you send v2.
thanks,
-- Shuah
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