Add some sanity tests for hmm_range_fault() returning the HMM_PFN_COMPOUND
flag.
Signed-off-by: Ralph Campbell <rcampbell@xxxxxxxxxx>
---
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).
*/
--
2.20.1
