To cover pagemap paths scanning PMD entries, add assertions to check whether a device-private PMD entry has the correct pagemap information - the PM_SWAP bit must be on in the pagemap entry. Before that, we must assert through HMM_DMIRROR_SNAPSHOT snapshot that the leaf entry is at PMD level and not PTE level.
Signed-off-by: Dev Jain <[email protected]> --- tools/testing/selftests/mm/hmm-tests.c | 29 ++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/tools/testing/selftests/mm/hmm-tests.c b/tools/testing/selftests/mm/hmm-tests.c index e1c8a679a4cf3..d09d4a9081de1 100644 --- a/tools/testing/selftests/mm/hmm-tests.c +++ b/tools/testing/selftests/mm/hmm-tests.c @@ -2276,8 +2276,11 @@ TEST_F(hmm, migrate_anon_huge_fault) unsigned long npages; unsigned long size; unsigned long i; + unsigned char *m; + uint64_t entry; void *old_ptr; void *map; + int pagemap_fd; int *ptr; int ret; @@ -2318,6 +2321,32 @@ TEST_F(hmm, migrate_anon_huge_fault) for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i) ASSERT_EQ(ptr[i], i); + if (!hmm_is_coherent_type(variant->device_number)) { + ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_SNAPSHOT, + buffer, npages); + ASSERT_EQ(ret, 0); + ASSERT_EQ(buffer->cpages, npages); + + m = buffer->mirror; + for (i = 0; i < npages; ++i) + ASSERT_EQ(m[i], HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL | + HMM_DMIRROR_PROT_WRITE | + HMM_DMIRROR_PROT_PMD); + + pagemap_fd = open("/proc/self/pagemap", O_RDONLY); + ASSERT_GE(pagemap_fd, 0); + + for (i = 0; i < npages; ++i) { + entry = pagemap_get_entry(pagemap_fd, + (char *)buffer->ptr + i * self->page_size); + + ASSERT_NE(entry & PM_SWAP, 0); + ASSERT_EQ(entry & PM_PRESENT, 0); + } + + close(pagemap_fd); + } + /* 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); -- 2.43.0
