[RFC PATCH v2 5/6] KVM: selftests: Add test cases for KVM_GUEST_MEMORY_FAILURE

isaku.yamahata
2023-09-21T20:41:55Z

From: Isaku Yamahata <isaku.yamahata@intel.com>

Add text cases for guest_memfd KVM_GUEST_MEMORY_FAILURE ioctl.
+ ioctl(KVM_GUEST_MEMORY_FAILURE) success with backing pages
+ ioctl(KVM_GUEST_MEMORY_FAILURE) fails with ENOENT without backing page
+ interaction with fallocate(PUNCH_HOLE)

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
---
.../testing/selftests/kvm/guest_memfd_test.c | 48 +++++++++++++++++++
1 file changed, 48 insertions(+)

diff --git a/tools/testing/selftests/kvm/guest_memfd_test.c b/tools/testing/selftests/kvm/guest_memfd_test.c
index d5b4bfcdc3fe..f8b242c9319d 100644
--- a/tools/testing/selftests/kvm/guest_memfd_test.c
+++ b/tools/testing/selftests/kvm/guest_memfd_test.c
@@ -122,6 +122,53 @@ static void test_fallocate_fail(int fd, size_t page_size, size_t total_size)
}
}

+static void test_memory_failure(int fd, size_t page_size, size_t total_size)
+{
+ struct kvm_guest_memory_failure mf;
+ int ret;
+ int i;
+
+ /* Make whole file unallocated as known initial state */
+ ret = fallocate(fd, FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE,
+ 0, total_size);
+ TEST_ASSERT(!ret, "fallocate(PUNCH_HOLE) at while file should succeed");
+
+ /* Because there is no backing page, fail to inject memory failure. */
+ for (i = 0; i < total_size / page_size; i++) {
+ mf = (struct kvm_guest_memory_failure) {
+ .offset = i * page_size,
+ };
+
+ ret = ioctl(fd, KVM_GUEST_MEMORY_FAILURE, &mf);
+ if (ret == -1 && errno == EPERM) {
+ pr_info("KVM_GUEST_MEMORY_FAILURE requires CAP_SYS_ADMIN. Skipping.\n")
+ return;
+ }
+ TEST_ASSERT(ret == -1 && errno == ENOENT,
+ "ioctl(KVM_GUEST_MEMORY_FAILURE) should fail i %d", i);
+ }
+
+ /* Allocate pages with index one and two. */
+ ret = fallocate(fd, FALLOC_FL_KEEP_SIZE, page_size, page_size * 2);
+ TEST_ASSERT(!ret, "fallocate beginning at page_size should succeed");
+
+ for (i = 0; i < total_size / page_size; i++) {
+ mf = (struct kvm_guest_memory_failure) {
+ .offset = i * page_size,
+ };
+
+ ret = ioctl(fd, KVM_GUEST_MEMORY_FAILURE, &mf);
+
+ if (i == 1 || i == 2) {
+ TEST_ASSERT(!ret || (ret == -1 && errno == EBUSY),
+ "ioctl(KVM_GUEST_MEMORY_FAILURE) should succeed i %d", i);
+ } else {
+ TEST_ASSERT(ret == -1 && errno == ENOENT,
+ "ioctl(KVM_GUEST_MEMORY_FAILURE) should fail i %d", i);
+ }
+ }
+}
+
static void test_create_guest_memfd_invalid(struct kvm_vm *vm)
{
uint64_t valid_flags = 0;
@@ -192,6 +239,7 @@ int main(int argc, char *argv[])
test_file_size(fd, page_size, total_size);
test_fallocate(fd, page_size, total_size);
test_fallocate_fail(fd, page_size, total_size);
+ test_memory_failure(fd, page_size, total_size);

close(fd);
}
--
2.25.1