[PATCH v10 31/41] KVM: selftests: Convert with allocated folios in different layouts
From: Ackerley Tng via B4 Relay <devnull+ackerleytng.google.com@kernel.org>
Date: 2026-08-07 21:52:50
Also in:
b4-sent, kvm, linux-coco, linux-doc, linux-kselftest, linux-mm, lkml
Subsystem:
kernel selftest framework, kernel virtual machine (kvm), kernel virtual machine for x86 (kvm/x86), the rest · Maintainers:
Shuah Khan, Shuah Khan, Paolo Bonzini, Sean Christopherson, Linus Torvalds
From: Ackerley Tng <redacted> Add a guest_memfd selftest to verify that memory conversions work correctly with allocated folios in different layouts. By iterating through which pages are initially faulted, the test covers various layouts of contiguous allocated and unallocated regions, exercising conversion with different range layouts. Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Fuad Tabba <redacted> Tested-by: Shivank Garg <redacted> Signed-off-by: Ackerley Tng <redacted> --- .../kvm/x86/guest_memfd_conversions_test.c | 30 ++++++++++++++++++++++ 1 file changed, 30 insertions(+)
diff --git a/tools/testing/selftests/kvm/x86/guest_memfd_conversions_test.c b/tools/testing/selftests/kvm/x86/guest_memfd_conversions_test.c
index f46f1530a94b9..acdff2d154046 100644
--- a/tools/testing/selftests/kvm/x86/guest_memfd_conversions_test.c
+++ b/tools/testing/selftests/kvm/x86/guest_memfd_conversions_test.c@@ -282,6 +282,36 @@ GMEM_CONVERSION_TEST_INIT_PRIVATE(before_allocation_private) test_convert_to_shared(t, 0, 0, 'A', 'B'); } +/* + * Test that when some of the folios in the conversion range are allocated, + * conversion requests are handled correctly in guest_memfd. Vary the ranges + * allocated before conversion, using test_page, to cover various layouts of + * contiguous allocated and unallocated regions. + */ +GMEM_CONVERSION_MULTIPAGE_TEST_INIT_SHARED(unallocated_folios, 8) +{ + const int second_page_to_fault = 4; + int i; + + /* + * Fault 2 of the pages to test filemap range operations except when + * test_page == second_page_to_fault. + */ + host_do_rmw(t->mem, test_page, 0, 'A'); + if (test_page != second_page_to_fault) + host_do_rmw(t->mem, second_page_to_fault, 0, 'A'); + + gmem_set_private(t->gmem_fd, 0, nr_pages * page_size); + for (i = 0; i < nr_pages; ++i) { + char expected = (i == test_page || i == second_page_to_fault) ? 'A' : 0; + + test_private(t, i, expected, 'B'); + } + + for (i = 0; i < nr_pages; ++i) + test_convert_to_shared(t, i, 'B', 'C', 'D'); +} + int main(int argc, char *argv[]) { TEST_REQUIRE(kvm_check_cap(KVM_CAP_VM_TYPES) & BIT(KVM_X86_SW_PROTECTED_VM));
--
2.55.0.654.g21b8a5bc05-goog