From f6c3e1ae0114cd0f5123cf38187d450c1b119e67 Mon Sep 17 00:00:00 2001 From: Ralph Campbell Date: Mon, 25 Jul 2022 11:36:15 -0700 Subject: [PATCH] mm/hmm: add a test for cross device private faults Add a simple test case for when hmm_range_fault() is called with the HMM_PFN_REQ_FAULT flag and a device private PTE is found for a device other than the hmm_range::dev_private_owner. This should cause the page to be faulted back to system memory from the other device and the PFN returned in the output array. Also, remove a piece of code that unnecessarily unmaps part of the buffer. Link: https://lkml.kernel.org/r/20220727000837.4128709-3-rcampbell@nvidia.com Link: https://lkml.kernel.org/r/20220725183615.4118795-3-rcampbell@nvidia.com Signed-off-by: Ralph Campbell Reviewed-by: Alistair Popple Cc: Felix Kuehling Cc: Philip Yang Cc: Jason Gunthorpe Signed-off-by: Andrew Morton --- tools/testing/selftests/vm/hmm-tests.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/vm/hmm-tests.c b/tools/testing/selftests/vm/hmm-tests.c index 716b62c05e3d..939a33dc5dc6 100644 --- a/tools/testing/selftests/vm/hmm-tests.c +++ b/tools/testing/selftests/vm/hmm-tests.c @@ -1603,9 +1603,19 @@ TEST_F(hmm2, double_map) for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i) ASSERT_EQ(ptr[i], i); - /* Punch a hole after the first page address. */ - ret = munmap(buffer->ptr + self->page_size, self->page_size); + /* Migrate pages to device 1 and try to read from device 0. */ + ret = hmm_dmirror_cmd(self->fd1, HMM_DMIRROR_MIGRATE, buffer, npages); ASSERT_EQ(ret, 0); + ASSERT_EQ(buffer->cpages, npages); + + ret = hmm_dmirror_cmd(self->fd0, HMM_DMIRROR_READ, buffer, npages); + ASSERT_EQ(ret, 0); + ASSERT_EQ(buffer->cpages, npages); + ASSERT_EQ(buffer->faults, 1); + + /* Check what device 0 read. */ + for (i = 0, ptr = buffer->mirror; i < size / sizeof(*ptr); ++i) + ASSERT_EQ(ptr[i], i); hmm_buffer_free(buffer); }