From: Matthew Brost <matthew.br...@intel.com> Add partial unmap test case which munmaps memory while in the device.
Add tests exercising mremap on faulted-in memory (CPU and GPU) at various offsets and verify correctness. Update anon_write_child to read device memory after fork verifying this flow works in the kernel. Both THP and non-THP cases are updated. Signed-off-by: Balbir Singh <balb...@nvidia.com> Signed-off-by: Matthew Brost <matthew.br...@intel.com> --- tools/testing/selftests/mm/hmm-tests.c | 312 ++++++++++++++++++++----- 1 file changed, 252 insertions(+), 60 deletions(-) diff --git a/tools/testing/selftests/mm/hmm-tests.c b/tools/testing/selftests/mm/hmm-tests.c index 339a90183930..dedc1049bd4d 100644 --- a/tools/testing/selftests/mm/hmm-tests.c +++ b/tools/testing/selftests/mm/hmm-tests.c @@ -50,6 +50,8 @@ enum { HMM_COHERENCE_DEVICE_TWO, }; +#define ONEKB (1 << 10) +#define ONEMEG (1 << 20) #define TWOMEG (1 << 21) #define HMM_BUFFER_SIZE (1024 << 12) #define HMM_PATH_MAX 64 @@ -525,6 +527,8 @@ TEST_F(hmm, anon_write_prot) /* * Check that a device writing an anonymous private mapping * will copy-on-write if a child process inherits the mapping. + * + * Also verifies after fork() memory the device can be read by child. */ TEST_F(hmm, anon_write_child) { @@ -532,72 +536,101 @@ TEST_F(hmm, anon_write_child) unsigned long npages; unsigned long size; unsigned long i; + void *old_ptr; + void *map; int *ptr; pid_t pid; int child_fd; - int ret; - - npages = ALIGN(HMM_BUFFER_SIZE, self->page_size) >> self->page_shift; - ASSERT_NE(npages, 0); - size = npages << self->page_shift; - - buffer = malloc(sizeof(*buffer)); - ASSERT_NE(buffer, NULL); - - buffer->fd = -1; - buffer->size = size; - buffer->mirror = malloc(size); - ASSERT_NE(buffer->mirror, NULL); - - buffer->ptr = mmap(NULL, size, - PROT_READ | PROT_WRITE, - MAP_PRIVATE | MAP_ANONYMOUS, - buffer->fd, 0); - ASSERT_NE(buffer->ptr, MAP_FAILED); - - /* Initialize buffer->ptr so we can tell if it is written. */ - for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) - ptr[i] = i; + int ret, use_thp, migrate; + + for (migrate = 0; migrate < 2; ++migrate) { + for (use_thp = 0; use_thp < 2; ++use_thp) { + npages = ALIGN(use_thp ? TWOMEG : HMM_BUFFER_SIZE, + self->page_size) >> self->page_shift; + ASSERT_NE(npages, 0); + size = npages << self->page_shift; + + buffer = malloc(sizeof(*buffer)); + ASSERT_NE(buffer, NULL); + + buffer->fd = -1; + buffer->size = size * 2; + buffer->mirror = malloc(size); + ASSERT_NE(buffer->mirror, NULL); + + buffer->ptr = mmap(NULL, size * 2, + PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, + buffer->fd, 0); + ASSERT_NE(buffer->ptr, MAP_FAILED); + + old_ptr = buffer->ptr; + if (use_thp) { + map = (void *)ALIGN((uintptr_t)buffer->ptr, size); + ret = madvise(map, size, MADV_HUGEPAGE); + ASSERT_EQ(ret, 0); + buffer->ptr = map; + } + + /* Initialize buffer->ptr so we can tell if it is written. */ + for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) + ptr[i] = i; + + /* Initialize data that the device will write to buffer->ptr. */ + for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i) + ptr[i] = -i; + + if (migrate) { + ret = hmm_migrate_sys_to_dev(self->fd, buffer, npages); + ASSERT_EQ(ret, 0); + ASSERT_EQ(buffer->cpages, npages); + + } + + pid = fork(); + if (pid == -1) + ASSERT_EQ(pid, 0); + if (pid != 0) { + waitpid(pid, &ret, 0); + ASSERT_EQ(WIFEXITED(ret), 1); + + /* Check that the parent's buffer did not change. */ + for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], i); + + buffer->ptr = old_ptr; + hmm_buffer_free(buffer); + continue; + } + + /* Check that we see the parent's values. */ + for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], i); + if (!migrate) { + for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], -i); + } + + /* The child process needs its own mirror to its own mm. */ + child_fd = hmm_open(0); + ASSERT_GE(child_fd, 0); + + /* Simulate a device writing system memory. */ + ret = hmm_dmirror_cmd(child_fd, HMM_DMIRROR_WRITE, buffer, npages); + ASSERT_EQ(ret, 0); + ASSERT_EQ(buffer->cpages, npages); + ASSERT_EQ(buffer->faults, 1); - /* Initialize data that the device will write to buffer->ptr. */ - for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i) - ptr[i] = -i; + /* Check what the device wrote. */ + if (!migrate) { + for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], -i); + } - pid = fork(); - if (pid == -1) - ASSERT_EQ(pid, 0); - if (pid != 0) { - waitpid(pid, &ret, 0); - ASSERT_EQ(WIFEXITED(ret), 1); - - /* Check that the parent's buffer did not change. */ - for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) - ASSERT_EQ(ptr[i], i); - return; + close(child_fd); + exit(0); + } } - - /* Check that we see the parent's values. */ - for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) - ASSERT_EQ(ptr[i], i); - for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i) - ASSERT_EQ(ptr[i], -i); - - /* The child process needs its own mirror to its own mm. */ - child_fd = hmm_open(0); - ASSERT_GE(child_fd, 0); - - /* Simulate a device writing system memory. */ - ret = hmm_dmirror_cmd(child_fd, HMM_DMIRROR_WRITE, buffer, npages); - ASSERT_EQ(ret, 0); - ASSERT_EQ(buffer->cpages, npages); - ASSERT_EQ(buffer->faults, 1); - - /* Check what the device wrote. */ - for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) - ASSERT_EQ(ptr[i], -i); - - close(child_fd); - exit(0); } /* @@ -2289,6 +2322,165 @@ TEST_F(hmm, migrate_anon_huge_fault) hmm_buffer_free(buffer); } +/* + * Migrate memory and fault back to sysmem after partially unmapping. + */ +TEST_F(hmm, migrate_partial_unmap_fault) +{ + struct hmm_buffer *buffer; + unsigned long npages; + unsigned long size = TWOMEG; + unsigned long i; + void *old_ptr; + void *map; + int *ptr; + int ret, j, use_thp; + int offsets[] = { 0, 512 * ONEKB, ONEMEG }; + + for (use_thp = 0; use_thp < 2; ++use_thp) { + for (j = 0; j < ARRAY_SIZE(offsets); ++j) { + buffer = malloc(sizeof(*buffer)); + ASSERT_NE(buffer, NULL); + + buffer->fd = -1; + buffer->size = 2 * size; + buffer->mirror = malloc(size); + ASSERT_NE(buffer->mirror, NULL); + memset(buffer->mirror, 0xFF, size); + + buffer->ptr = mmap(NULL, 2 * size, + PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, + buffer->fd, 0); + ASSERT_NE(buffer->ptr, MAP_FAILED); + + npages = size >> self->page_shift; + map = (void *)ALIGN((uintptr_t)buffer->ptr, size); + if (use_thp) + ret = madvise(map, size, MADV_HUGEPAGE); + else + ret = madvise(map, size, MADV_NOHUGEPAGE); + ASSERT_EQ(ret, 0); + old_ptr = buffer->ptr; + buffer->ptr = map; + + /* Initialize buffer in system memory. */ + for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) + ptr[i] = i; + + /* Migrate memory to device. */ + ret = hmm_migrate_sys_to_dev(self->fd, buffer, npages); + ASSERT_EQ(ret, 0); + ASSERT_EQ(buffer->cpages, npages); + + /* Check what the device read. */ + for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], i); + + munmap(buffer->ptr + offsets[j], ONEMEG); + + /* Fault pages back to system memory and check them. */ + for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) + if (i * sizeof(int) < offsets[j] || + i * sizeof(int) >= offsets[j] + ONEMEG) + ASSERT_EQ(ptr[i], i); + + buffer->ptr = old_ptr; + hmm_buffer_free(buffer); + } + } +} + +TEST_F(hmm, migrate_remap_fault) +{ + struct hmm_buffer *buffer; + unsigned long npages; + unsigned long size = TWOMEG; + unsigned long i; + void *old_ptr, *new_ptr = NULL; + void *map; + int *ptr; + int ret, j, use_thp, dont_unmap, before; + int offsets[] = { 0, 512 * ONEKB, ONEMEG }; + + for (before = 0; before < 2; ++before) { + for (dont_unmap = 0; dont_unmap < 2; ++dont_unmap) { + for (use_thp = 0; use_thp < 2; ++use_thp) { + for (j = 0; j < ARRAY_SIZE(offsets); ++j) { + int flags = MREMAP_MAYMOVE | MREMAP_FIXED; + + if (dont_unmap) + flags |= MREMAP_DONTUNMAP; + + buffer = malloc(sizeof(*buffer)); + ASSERT_NE(buffer, NULL); + + buffer->fd = -1; + buffer->size = 8 * size; + buffer->mirror = malloc(size); + ASSERT_NE(buffer->mirror, NULL); + memset(buffer->mirror, 0xFF, size); + + buffer->ptr = mmap(NULL, buffer->size, + PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, + buffer->fd, 0); + ASSERT_NE(buffer->ptr, MAP_FAILED); + + npages = size >> self->page_shift; + map = (void *)ALIGN((uintptr_t)buffer->ptr, size); + if (use_thp) + ret = madvise(map, size, MADV_HUGEPAGE); + else + ret = madvise(map, size, MADV_NOHUGEPAGE); + ASSERT_EQ(ret, 0); + old_ptr = buffer->ptr; + munmap(map + size, size * 2); + buffer->ptr = map; + + /* Initialize buffer in system memory. */ + for (i = 0, ptr = buffer->ptr; + i < size / sizeof(*ptr); ++i) + ptr[i] = i; + + if (before) { + new_ptr = mremap((void *)map, size, size, flags, + map + size + offsets[j]); + ASSERT_NE(new_ptr, MAP_FAILED); + buffer->ptr = new_ptr; + } + + /* Migrate memory to device. */ + ret = hmm_migrate_sys_to_dev(self->fd, buffer, npages); + ASSERT_EQ(ret, 0); + ASSERT_EQ(buffer->cpages, npages); + + /* Check what the device read. */ + for (i = 0, ptr = buffer->mirror; + i < size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], i); + + if (!before) { + new_ptr = mremap((void *)map, size, size, flags, + map + size + offsets[j]); + ASSERT_NE(new_ptr, MAP_FAILED); + buffer->ptr = new_ptr; + } + + /* Fault pages back to system memory and check them. */ + for (i = 0, ptr = buffer->ptr; + i < size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], i); + + munmap(new_ptr, size); + buffer->ptr = old_ptr; + hmm_buffer_free(buffer); + } + } + } + } +} + /* * Migrate private anonymous huge page with allocation errors. */ -- 2.50.1