mm/hmm: add tests for hmm_pfn_to_map_order()

[linux-block.git] / tools / testing / selftests / vm / hmm-tests.c

diff --git a/tools/testing/selftests/vm/hmm-tests.c b/tools/testing/selftests/vm/hmm-tests.c
index 79db22604019de1a2b8ef150e828122dc67772e8..b533dd08da1dcdbe122411e5aa94034bd60974b9 100644 (file)
--- 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_PMD 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_PMD);
+
+       /* 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_PMD);
+
+       free_hugepage_region(buffer->ptr);
+       buffer->ptr = NULL;
+       hmm_buffer_free(buffer);
+}
+
 /*
  * Test two devices reading the same memory (double mapped).
  */