[PATCH V4 31/31] selftests/sgx: Page removal stress test

[Reinette Chatre]

Create enclave with additional heap that consumes all physical SGX
memory and then remove it.

Depending on the available SGX memory this test could take a
significant time to run (several minutes) as it (1) creates the
enclave, (2) changes the type of every page to be trimmed,
(3) enters the enclave once per page to run EACCEPT, before
(4) the pages are finally removed.

Acked-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
Signed-off-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
---
Changes since V3:
- Add Jarkko's Acked-by tag.
- Rename SGX_IOC_ENCLAVE_MODIFY_TYPE to
  SGX_IOC_ENCLAVE_MODIFY_TYPES. (Jarkko)
- User provides just page type to SGX_IOC_ENCLAVE_MODIFY_TYPES ioctl(),
  replacing secinfo. (Jarkko)
- Let the SKIP() call involving SGX_IOC_ENCLAVE_MODIFY_TYPES span
  two lines to address checkpatch.pl warning triggered by new longer
  name.

Changes since V2:
- Rename struct sgx_enclave_modt -> struct sgx_enclave_modify_type

Changes since V1:
- Exit test completely on first failure of EACCEPT of a removed page. Since
  this is an oversubscribed test the number of pages on which this is
  attempted can be significant and in case of failure the per-page
  error logging would overwhelm the system.
- Update test to call renamed ioctl() (SGX_IOC_PAGE_MODT ->
  SGX_IOC_ENCLAVE_MODIFY_TYPE) and provide secinfo as parameter (Jarkko).
- Fixup definitions to be reverse xmas tree.
- Update test to reflect page removal ioctl() and struct name change:
  SGX_IOC_PAGE_REMOVE->SGX_IOC_ENCLAVE_REMOVE_PAGES,
  struct sgx_page_remove -> struct sgx_enclave_remove_pages (Jarkko).
- Ensure test is skipped when SGX2 not supported by kernel.
- Cleanup comments.

 tools/testing/selftests/sgx/main.c | 120 +++++++++++++++++++++++++++++
 1 file changed, 120 insertions(+)

diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c
index d49fce1a8df9..7ad88117f3f7 100644
--- a/tools/testing/selftests/sgx/main.c
+++ b/tools/testing/selftests/sgx/main.c
@@ -378,7 +378,127 @@ TEST_F(enclave, unclobbered_vdso_oversubscribed)
 	EXPECT_EQ(get_op.value, MAGIC);
 	EXPECT_EEXIT(&self->run);
 	EXPECT_EQ(self->run.user_data, 0);
+}
+
+TEST_F_TIMEOUT(enclave, unclobbered_vdso_oversubscribed_remove, 900)
+{
+	struct sgx_enclave_remove_pages remove_ioc;
+	struct sgx_enclave_modify_type modt_ioc;
+	struct encl_op_get_from_buf get_op;
+	struct encl_op_eaccept eaccept_op;
+	struct encl_op_put_to_buf put_op;
+	struct encl_segment *heap;
+	unsigned long total_mem;
+	int ret, errno_save;
+	unsigned long addr;
+	unsigned long i;
+
+	/*
+	 * Create enclave with additional heap that is as big as all
+	 * available physical SGX memory.
+	 */
+	total_mem = get_total_epc_mem();
+	ASSERT_NE(total_mem, 0);
+	TH_LOG("Creating an enclave with %lu bytes heap may take a while ...",
+	       total_mem);
+	ASSERT_TRUE(setup_test_encl(total_mem, &self->encl, _metadata));
+
+	/*
+	 * Hardware (SGX2) and kernel support is needed for this test. Start
+	 * with check that test has a chance of succeeding.
+	 */
+	memset(&modt_ioc, 0, sizeof(modt_ioc));
+	ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_MODIFY_TYPES, &modt_ioc);
+
+	if (ret == -1) {
+		if (errno == ENOTTY)
+			SKIP(return,
+			     "Kernel does not support SGX_IOC_ENCLAVE_MODIFY_TYPES ioctl()");
+		else if (errno == ENODEV)
+			SKIP(return, "System does not support SGX2");
+	}
+
+	/*
+	 * Invalid parameters were provided during sanity check,
+	 * expect command to fail.
+	 */
+	EXPECT_EQ(ret, -1);
+
+	/* SGX2 is supported by kernel and hardware, test can proceed. */
+	memset(&self->run, 0, sizeof(self->run));
+	self->run.tcs = self->encl.encl_base;
+
+	heap = &self->encl.segment_tbl[self->encl.nr_segments - 1];
+
+	put_op.header.type = ENCL_OP_PUT_TO_BUFFER;
+	put_op.value = MAGIC;
+
+	EXPECT_EQ(ENCL_CALL(&put_op, &self->run, false), 0);
+
+	EXPECT_EEXIT(&self->run);
+	EXPECT_EQ(self->run.user_data, 0);
+
+	get_op.header.type = ENCL_OP_GET_FROM_BUFFER;
+	get_op.value = 0;
+
+	EXPECT_EQ(ENCL_CALL(&get_op, &self->run, false), 0);
+
+	EXPECT_EQ(get_op.value, MAGIC);
+	EXPECT_EEXIT(&self->run);
+	EXPECT_EQ(self->run.user_data, 0);
 
+	/* Trim entire heap. */
+	memset(&modt_ioc, 0, sizeof(modt_ioc));
+
+	modt_ioc.offset = heap->offset;
+	modt_ioc.length = heap->size;
+	modt_ioc.page_type = SGX_PAGE_TYPE_TRIM;
+
+	TH_LOG("Changing type of %zd bytes to trimmed may take a while ...",
+	       heap->size);
+	ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_MODIFY_TYPES, &modt_ioc);
+	errno_save = ret == -1 ? errno : 0;
+
+	EXPECT_EQ(ret, 0);
+	EXPECT_EQ(errno_save, 0);
+	EXPECT_EQ(modt_ioc.result, 0);
+	EXPECT_EQ(modt_ioc.count, heap->size);
+
+	/* EACCEPT all removed pages. */
+	addr = self->encl.encl_base + heap->offset;
+
+	eaccept_op.flags = SGX_SECINFO_TRIM | SGX_SECINFO_MODIFIED;
+	eaccept_op.header.type = ENCL_OP_EACCEPT;
+
+	TH_LOG("Entering enclave to run EACCEPT for each page of %zd bytes may take a while ...",
+	       heap->size);
+	for (i = 0; i < heap->size; i += 4096) {
+		eaccept_op.epc_addr = addr + i;
+		eaccept_op.ret = 0;
+
+		EXPECT_EQ(ENCL_CALL(&eaccept_op, &self->run, true), 0);
+
+		EXPECT_EQ(self->run.exception_vector, 0);
+		EXPECT_EQ(self->run.exception_error_code, 0);
+		EXPECT_EQ(self->run.exception_addr, 0);
+		ASSERT_EQ(eaccept_op.ret, 0);
+		ASSERT_EQ(self->run.function, EEXIT);
+	}
+
+	/* Complete page removal. */
+	memset(&remove_ioc, 0, sizeof(remove_ioc));
+
+	remove_ioc.offset = heap->offset;
+	remove_ioc.length = heap->size;
+
+	TH_LOG("Removing %zd bytes from enclave may take a while ...",
+	       heap->size);
+	ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_REMOVE_PAGES, &remove_ioc);
+	errno_save = ret == -1 ? errno : 0;
+
+	EXPECT_EQ(ret, 0);
+	EXPECT_EQ(errno_save, 0);
+	EXPECT_EQ(remove_ioc.count, heap->size);
 }
 
 TEST_F(enclave, clobbered_vdso)
-- 
2.25.1