Add some sanity tests for hmm_range_fault() returning the HMM_PFN_COMPOUND flag.
Signed-off-by: Ralph Campbell rcampbell@nvidia.com --- lib/test_hmm.c | 2 + lib/test_hmm_uapi.h | 2 + tools/testing/selftests/vm/hmm-tests.c | 76 ++++++++++++++++++++++++++ 3 files changed, 80 insertions(+)
diff --git a/lib/test_hmm.c b/lib/test_hmm.c index 00bca6116f93..8448921e6d33 100644 --- a/lib/test_hmm.c +++ b/lib/test_hmm.c @@ -757,6 +757,8 @@ static void dmirror_mkentry(struct dmirror *dmirror, struct hmm_range *range, *perm |= HMM_DMIRROR_PROT_WRITE; else *perm |= HMM_DMIRROR_PROT_READ; + if (entry & HMM_PFN_COMPOUND) + *perm |= HMM_DMIRROR_PROT_COMPOUND; }
static bool dmirror_snapshot_invalidate(struct mmu_interval_notifier *mni, diff --git a/lib/test_hmm_uapi.h b/lib/test_hmm_uapi.h index 67b3b2e6ff5d..21cf4da6f020 100644 --- a/lib/test_hmm_uapi.h +++ b/lib/test_hmm_uapi.h @@ -40,6 +40,7 @@ struct hmm_dmirror_cmd { * HMM_DMIRROR_PROT_NONE: unpopulated PTE or PTE with no access * HMM_DMIRROR_PROT_READ: read-only PTE * HMM_DMIRROR_PROT_WRITE: read/write PTE + * HMM_DMIRROR_PROT_COMPOUND: compound page is fully mapped by same permissions * HMM_DMIRROR_PROT_ZERO: special read-only zero page * HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL: Migrated device private page on the * device the ioctl() is made @@ -51,6 +52,7 @@ enum { HMM_DMIRROR_PROT_NONE = 0x00, HMM_DMIRROR_PROT_READ = 0x01, HMM_DMIRROR_PROT_WRITE = 0x02, + HMM_DMIRROR_PROT_COMPOUND = 0x04, HMM_DMIRROR_PROT_ZERO = 0x10, HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL = 0x20, HMM_DMIRROR_PROT_DEV_PRIVATE_REMOTE = 0x30, diff --git a/tools/testing/selftests/vm/hmm-tests.c b/tools/testing/selftests/vm/hmm-tests.c index 79db22604019..e9576d9802c7 100644 --- a/tools/testing/selftests/vm/hmm-tests.c +++ b/tools/testing/selftests/vm/hmm-tests.c @@ -1291,6 +1291,82 @@ TEST_F(hmm2, snapshot) hmm_buffer_free(buffer); }
+/* + * Test the hmm_range_fault() HMM_PFN_COMPOUND flag for large pages that + * should be mapped by a large page table entry. + */ +TEST_F(hmm, compound) +{ + struct hmm_buffer *buffer; + unsigned long npages; + unsigned long size; + int *ptr; + unsigned char *m; + int ret; + long pagesizes[4]; + int n, idx; + unsigned long i; + + /* Skip test if we can't allocate a hugetlbfs page. */ + + n = gethugepagesizes(pagesizes, 4); + if (n <= 0) + return; + for (idx = 0; --n > 0; ) { + if (pagesizes[n] < pagesizes[idx]) + idx = n; + } + size = ALIGN(TWOMEG, pagesizes[idx]); + npages = size >> self->page_shift; + + buffer = malloc(sizeof(*buffer)); + ASSERT_NE(buffer, NULL); + + buffer->ptr = get_hugepage_region(size, GHR_STRICT); + if (buffer->ptr == NULL) { + free(buffer); + return; + } + + buffer->size = size; + buffer->mirror = malloc(npages); + ASSERT_NE(buffer->mirror, NULL); + + /* Initialize the pages the device will snapshot in buffer->ptr. */ + for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i) + ptr[i] = i; + + /* Simulate a device snapshotting CPU pagetables. */ + ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_SNAPSHOT, buffer, npages); + ASSERT_EQ(ret, 0); + ASSERT_EQ(buffer->cpages, npages); + + /* Check what the device saw. */ + m = buffer->mirror; + for (i = 0; i < npages; ++i) + ASSERT_EQ(m[i], HMM_DMIRROR_PROT_WRITE | + HMM_DMIRROR_PROT_COMPOUND); + + /* Make the region read-only. */ + ret = mprotect(buffer->ptr, size, PROT_READ); + ASSERT_EQ(ret, 0); + + /* Simulate a device snapshotting CPU pagetables. */ + ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_SNAPSHOT, buffer, npages); + ASSERT_EQ(ret, 0); + ASSERT_EQ(buffer->cpages, npages); + + /* Check what the device saw. */ + m = buffer->mirror; + for (i = 0; i < npages; ++i) + ASSERT_EQ(m[i], HMM_DMIRROR_PROT_READ | + HMM_DMIRROR_PROT_COMPOUND); + + free_hugepage_region(buffer->ptr); + buffer->ptr = NULL; + hmm_buffer_free(buffer); +} + /* * Test two devices reading the same memory (double mapped). */