[RFC PATCH v1 8/9] KVM: guest_memfd: selftests: guest_memfd mmap() test when mapping is allowed

[Fuad Tabba <tabba@google.com>]

Expand the guest_memfd selftests to include testing mapping guest
memory if the capability is supported, and that still checks that
memory is not mappable if the capability isn't supported.

Also, build the guest_memfd selftest for aarch64.

Signed-off-by: Fuad Tabba <tabba@google.com>
---
 tools/testing/selftests/kvm/Makefile          |  1 +
 .../testing/selftests/kvm/guest_memfd_test.c  | 60 +++++++++++++++++--
 tools/testing/selftests/kvm/lib/kvm_util.c    |  3 +-
 3 files changed, 57 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 41593d2e7de9..c998eb3c3b77 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -174,6 +174,7 @@ TEST_GEN_PROGS_aarch64 += coalesced_io_test
 TEST_GEN_PROGS_aarch64 += demand_paging_test
 TEST_GEN_PROGS_aarch64 += dirty_log_test
 TEST_GEN_PROGS_aarch64 += dirty_log_perf_test
+TEST_GEN_PROGS_aarch64 += guest_memfd_test
 TEST_GEN_PROGS_aarch64 += guest_print_test
 TEST_GEN_PROGS_aarch64 += get-reg-list
 TEST_GEN_PROGS_aarch64 += kvm_create_max_vcpus
diff --git a/tools/testing/selftests/kvm/guest_memfd_test.c b/tools/testing/selftests/kvm/guest_memfd_test.c
index ce687f8d248f..6c501cb865f3 100644
--- a/tools/testing/selftests/kvm/guest_memfd_test.c
+++ b/tools/testing/selftests/kvm/guest_memfd_test.c
@@ -34,12 +34,55 @@ static void test_file_read_write(int fd)
 		    "pwrite on a guest_mem fd should fail");
 }
 
-static void test_mmap(int fd, size_t page_size)
+static void test_mmap_allowed(int fd, size_t total_size)
 {
+	size_t page_size = getpagesize();
+	char *mem;
+	int ret;
+	int i;
+
+	mem = mmap(NULL, total_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+	TEST_ASSERT(mem != MAP_FAILED, "mmaping() guest memory should pass.");
+
+	memset(mem, 0xaa, total_size);
+	for (i = 0; i < total_size; i++)
+		TEST_ASSERT_EQ(mem[i], 0xaa);
+
+	ret = fallocate(fd, FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE, 0,
+			page_size);
+	TEST_ASSERT(!ret, "fallocate the first page should succeed");
+
+	for (i = 0; i < page_size; i++)
+		TEST_ASSERT_EQ(mem[i], 0x00);
+	for (; i < total_size; i++)
+		TEST_ASSERT_EQ(mem[i], 0xaa);
+
+	memset(mem, 0xaa, total_size);
+	for (i = 0; i < total_size; i++)
+		TEST_ASSERT_EQ(mem[i], 0xaa);
+
+	ret = munmap(mem, total_size);
+	TEST_ASSERT(!ret, "munmap should succeed");
+}
+
+static void test_mmap_denied(int fd, size_t total_size)
+{
+	size_t page_size = getpagesize();
 	char *mem;
 
 	mem = mmap(NULL, page_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
 	TEST_ASSERT_EQ(mem, MAP_FAILED);
+
+	mem = mmap(NULL, total_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+	TEST_ASSERT_EQ(mem, MAP_FAILED);
+}
+
+static void test_mmap(int fd, size_t total_size)
+{
+	if (kvm_has_cap(KVM_CAP_GUEST_MEMFD_MAPPABLE))
+		test_mmap_allowed(fd, total_size);
+	else
+		test_mmap_denied(fd, total_size);
 }
 
 static void test_file_size(int fd, size_t page_size, size_t total_size)
@@ -172,17 +215,24 @@ static void test_create_guest_memfd_multiple(struct kvm_vm *vm)
 
 int main(int argc, char *argv[])
 {
-	size_t page_size;
+	unsigned long type = VM_TYPE_DEFAULT;
+	struct kvm_vm *vm;
 	size_t total_size;
+	size_t page_size;
 	int fd;
-	struct kvm_vm *vm;
 
 	TEST_REQUIRE(kvm_has_cap(KVM_CAP_GUEST_MEMFD));
 
+	if (kvm_has_cap(KVM_CAP_GUEST_MEMFD_MAPPABLE)) {
+#ifdef __aarch64__
+		type = KVM_VM_TYPE_ARM_SW_PROTECTED;
+#endif
+	}
+
 	page_size = getpagesize();
 	total_size = page_size * 4;
 
-	vm = vm_create_barebones();
+	vm = vm_create_barebones_type(type);
 
 	test_create_guest_memfd_invalid(vm);
 	test_create_guest_memfd_multiple(vm);
@@ -190,7 +240,7 @@ int main(int argc, char *argv[])
 	fd = vm_create_guest_memfd(vm, total_size, 0);
 
 	test_file_read_write(fd);
-	test_mmap(fd, page_size);
+	test_mmap(fd, total_size);
 	test_file_size(fd, page_size, total_size);
 	test_fallocate(fd, page_size, total_size);
 	test_invalid_punch_hole(fd, page_size, total_size);
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 480e3a40d197..098ea04ec099 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -347,9 +347,8 @@ struct kvm_vm *____vm_create(struct vm_shape shape)
 	}
 
 #ifdef __aarch64__
-	TEST_ASSERT(!vm->type, "ARM doesn't support test-provided types");
 	if (vm->pa_bits != 40)
-		vm->type = KVM_VM_TYPE_ARM_IPA_SIZE(vm->pa_bits);
+		vm->type |= KVM_VM_TYPE_ARM_IPA_SIZE(vm->pa_bits);
 #endif
 
 	vm_open(vm);
-- 
2.48.0.rc2.279.g1de40edade-goog