Enhance the guest_memfd indexing selftest to also verify the precision of memory conversions between private and shared.
The existing test converted a single page within a multi-page mapping but did not explicitly check the state of the surrounding pages after the conversion loop. Add checks to confirm that converting a single page from shared to private only affects the target page. Iterate through all other pages in the guest_memfd region to ensure they remain in their original shared state, thus verifying that the conversion operation is precise and does not have unintended side effects. Signed-off-by: Ackerley Tng <[email protected]> --- .../selftests/kvm/guest_memfd_conversions_test.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/kvm/guest_memfd_conversions_test.c b/tools/testing/selftests/kvm/guest_memfd_conversions_test.c index 9dc47316112f..b109f078bc6b 100644 --- a/tools/testing/selftests/kvm/guest_memfd_conversions_test.c +++ b/tools/testing/selftests/kvm/guest_memfd_conversions_test.c @@ -227,7 +227,8 @@ GMEM_CONVERSION_TEST_INIT_SHARED(init_shared) /* * Test indexing of pages within guest_memfd, using test data that is a multiple - * of page index. + * of page index. Also test the precision of conversion, that it does not + * affect surrounding pages. */ GMEM_CONVERSION_MULTIPAGE_TEST_INIT_SHARED(indexing, 4) { @@ -247,12 +248,20 @@ GMEM_CONVERSION_MULTIPAGE_TEST_INIT_SHARED(indexing, 4) test_shared(t, i, i * 2, i * 3, i * 4); } + /* Confirm that only one page was converted */ for (i = 0; i < nr_pages; ++i) { if (i == test_page) - test_convert_to_shared(t, i, i * 4, i * 5, i * 6); + test_private(t, i, i * 4, i * 6); else test_shared(t, i, i * 4, i * 5, i * 6); } + + for (i = 0; i < nr_pages; ++i) { + if (i == test_page) + test_convert_to_shared(t, i, i * 6, i * 7, i * 8); + else + test_shared(t, i, i * 6, i * 7, i * 8); + } } /* -- 2.53.0.rc1.225.gd81095ad13-goog
