summaryrefslogtreecommitdiff
path: root/tools/testing
diff options
context:
space:
mode:
authorAlistair Popple <apopple@nvidia.com>2021-07-01 04:54:28 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2021-07-01 21:06:03 +0300
commitb659baea75469f0c5bd26f18461dfcdc1bbbac82 (patch)
treee1ab072a9d092d11ad6eb67574ef9b0bf6aba397 /tools/testing
parentb756a3b5e7ead8f6f4b03cea8ac22478ce04c8a8 (diff)
downloadlinux-b659baea75469f0c5bd26f18461dfcdc1bbbac82.tar.xz
mm: selftests for exclusive device memory
Adds some selftests for exclusive device memory. Link: https://lkml.kernel.org/r/20210616105937.23201-9-apopple@nvidia.com Signed-off-by: Alistair Popple <apopple@nvidia.com> Acked-by: Jason Gunthorpe <jgg@nvidia.com> Tested-by: Ralph Campbell <rcampbell@nvidia.com> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com> Cc: Ben Skeggs <bskeggs@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hugh Dickins <hughd@google.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Peter Xu <peterx@redhat.com> Cc: Shakeel Butt <shakeelb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'tools/testing')
-rw-r--r--tools/testing/selftests/vm/hmm-tests.c158
1 files changed, 158 insertions, 0 deletions
diff --git a/tools/testing/selftests/vm/hmm-tests.c b/tools/testing/selftests/vm/hmm-tests.c
index 5d1ac691b9f4..864f126ffd78 100644
--- a/tools/testing/selftests/vm/hmm-tests.c
+++ b/tools/testing/selftests/vm/hmm-tests.c
@@ -1485,4 +1485,162 @@ TEST_F(hmm2, double_map)
hmm_buffer_free(buffer);
}
+/*
+ * Basic check of exclusive faulting.
+ */
+TEST_F(hmm, exclusive)
+{
+ struct hmm_buffer *buffer;
+ unsigned long npages;
+ unsigned long size;
+ unsigned long i;
+ int *ptr;
+ 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 in system memory. */
+ for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i)
+ ptr[i] = i;
+
+ /* Map memory exclusively for device access. */
+ ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_EXCLUSIVE, 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);
+
+ /* 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);
+
+ for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i)
+ ASSERT_EQ(ptr[i], i+1);
+
+ /* Check atomic access revoked */
+ ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_CHECK_EXCLUSIVE, buffer, npages);
+ ASSERT_EQ(ret, 0);
+
+ hmm_buffer_free(buffer);
+}
+
+TEST_F(hmm, exclusive_mprotect)
+{
+ struct hmm_buffer *buffer;
+ unsigned long npages;
+ unsigned long size;
+ unsigned long i;
+ int *ptr;
+ 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 in system memory. */
+ for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i)
+ ptr[i] = i;
+
+ /* Map memory exclusively for device access. */
+ ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_EXCLUSIVE, 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);
+
+ ret = mprotect(buffer->ptr, size, PROT_READ);
+ ASSERT_EQ(ret, 0);
+
+ /* Simulate a device writing system memory. */
+ ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_WRITE, buffer, npages);
+ ASSERT_EQ(ret, -EPERM);
+
+ hmm_buffer_free(buffer);
+}
+
+/*
+ * Check copy-on-write works.
+ */
+TEST_F(hmm, exclusive_cow)
+{
+ struct hmm_buffer *buffer;
+ unsigned long npages;
+ unsigned long size;
+ unsigned long i;
+ int *ptr;
+ 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 in system memory. */
+ for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i)
+ ptr[i] = i;
+
+ /* Map memory exclusively for device access. */
+ ret = hmm_dmirror_cmd(self->fd, HMM_DMIRROR_EXCLUSIVE, buffer, npages);
+ ASSERT_EQ(ret, 0);
+ ASSERT_EQ(buffer->cpages, npages);
+
+ fork();
+
+ /* 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);
+
+ for (i = 0, ptr = buffer->ptr; i < size / sizeof(*ptr); ++i)
+ ASSERT_EQ(ptr[i], i+1);
+
+ hmm_buffer_free(buffer);
+}
+
TEST_HARNESS_MAIN