selftests: drivers/s390x: Add uvdevice tests

Adds some selftests to test ioctl error paths of the uv-uapi.
The Kconfig S390_UV_UAPI must be selected and the Ultravisor facility
must be available. The test can be executed by non-root, however, the
uvdevice special file /dev/uv must be accessible for reading and
writing which may imply root privileges.

./test-uv-device
TAP version 13
1..6
# Starting 6 tests from 3 test cases.
# RUN uvio_fixture.att.fault_ioctl_arg ...
# OK uvio_fixture.att.fault_ioctl_arg
ok 1 uvio_fixture.att.fault_ioctl_arg
# RUN uvio_fixture.att.fault_uvio_arg ...
# OK uvio_fixture.att.fault_uvio_arg
ok 2 uvio_fixture.att.fault_uvio_arg
# RUN uvio_fixture.att.inval_ioctl_cb ...
# OK uvio_fixture.att.inval_ioctl_cb
ok 3 uvio_fixture.att.inval_ioctl_cb
# RUN uvio_fixture.att.inval_ioctl_cmd ...
# OK uvio_fixture.att.inval_ioctl_cmd
ok 4 uvio_fixture.att.inval_ioctl_cmd
# RUN attest_fixture.att_inval_request ...
# OK attest_fixture.att_inval_request
ok 5 attest_fixture.att_inval_request
# RUN attest_fixture.att_inval_addr ...
# OK attest_fixture.att_inval_addr
ok 6 attest_fixture.att_inval_addr
# PASSED: 6 / 6 tests passed.
# Totals: pass:6 fail:0 xfail:0 xpass:0 skip:0 error:0

Signed-off-by: Steffen Eiden <[e-mail]>
Acked-by: Janosch Frank <[e-mail]>
Message-Id: <[e-mail]>
Link: https://lore.kernel.org/kvm/[e-mail]/
Signed-off-by: Janosch Frank <[e-mail]>

MAINTAINERS

···
 F:	arch/s390/kvm/
 F:	arch/s390/mm/gmap.c
 F:	drivers/s390/char/uvdevice.c
+F:	tools/testing/selftests/drivers/s390x/uvdevice/
 F:	tools/testing/selftests/kvm/*/s390x/
 F:	tools/testing/selftests/kvm/s390x/
 

tools/testing/selftests/Makefile

···
 TARGETS += cpufreq
 TARGETS += cpu-hotplug
 TARGETS += drivers/dma-buf
+TARGETS += drivers/s390x/uvdevice
 TARGETS += efivarfs
 TARGETS += exec
 TARGETS += filesystems

tools/testing/selftests/drivers/.gitignore

···
 # SPDX-License-Identifier: GPL-2.0-only
 /dma-buf/udmabuf
+/s390x/uvdevice/test_uvdevice

tools/testing/selftests/drivers/s390x/uvdevice/Makefile

···
+include ../../../../../build/Build.include
+
+UNAME_M := $(shell uname -m)
+
+ifneq ($(UNAME_M),s390x)
+nothing:
+.PHONY: all clean run_tests install
+.SILENT:
+else
+
+TEST_GEN_PROGS := test_uvdevice
+
+top_srcdir ?= ../../../../../..
+KSFT_KHDR_INSTALL := 1
+khdr_dir = $(top_srcdir)/usr/include
+LINUX_TOOL_ARCH_INCLUDE = $(top_srcdir)/tools/arch/$(ARCH)/include
+
+CFLAGS += -Wall -Werror -static -I$(khdr_dir) -I$(LINUX_TOOL_ARCH_INCLUDE)
+
+include ../../../lib.mk
+
+endif

tools/testing/selftests/drivers/s390x/uvdevice/config

···
+CONFIG_S390_UV_UAPI=y

tools/testing/selftests/drivers/s390x/uvdevice/test_uvdevice.c

···
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  selftest for the Ultravisor UAPI device
+ *
+ *  Copyright IBM Corp. 2022
+ *  Author(s): Steffen Eiden <[e-mail]>
+ */
+
+#include <stdint.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+
+#include <asm/uvdevice.h>
+
+#include "../../../kselftest_harness.h"
+
+#define UV_PATH  "/dev/uv"
+#define BUFFER_SIZE 0x200
+FIXTURE(uvio_fixture) {
+	int uv_fd;
+	struct uvio_ioctl_cb uvio_ioctl;
+	uint8_t buffer[BUFFER_SIZE];
+	__u64 fault_page;
+};
+
+FIXTURE_VARIANT(uvio_fixture) {
+	unsigned long ioctl_cmd;
+	uint32_t arg_size;
+};
+
+FIXTURE_VARIANT_ADD(uvio_fixture, att) {
+	.ioctl_cmd = UVIO_IOCTL_ATT,
+	.arg_size = sizeof(struct uvio_attest),
+};
+
+FIXTURE_SETUP(uvio_fixture)
+{
+	self->uv_fd = open(UV_PATH, O_ACCMODE);
+
+	self->uvio_ioctl.argument_addr = (__u64)self->buffer;
+	self->uvio_ioctl.argument_len = variant->arg_size;
+	self->fault_page =
+		(__u64)mmap(NULL, (size_t)getpagesize(), PROT_NONE, MAP_ANONYMOUS, -1, 0);
+}
+
+FIXTURE_TEARDOWN(uvio_fixture)
+{
+	if (self->uv_fd)
+		close(self->uv_fd);
+	munmap((void *)self->fault_page, (size_t)getpagesize());
+}
+
+TEST_F(uvio_fixture, fault_ioctl_arg)
+{
+	int rc, errno_cache;
+
+	rc = ioctl(self->uv_fd, variant->ioctl_cmd, NULL);
+	errno_cache = errno;
+	ASSERT_EQ(rc, -1);
+	ASSERT_EQ(errno_cache, EFAULT);
+
+	rc = ioctl(self->uv_fd, variant->ioctl_cmd, self->fault_page);
+	errno_cache = errno;
+	ASSERT_EQ(rc, -1);
+	ASSERT_EQ(errno_cache, EFAULT);
+}
+
+TEST_F(uvio_fixture, fault_uvio_arg)
+{
+	int rc, errno_cache;
+
+	self->uvio_ioctl.argument_addr = 0;
+	rc = ioctl(self->uv_fd, variant->ioctl_cmd, &self->uvio_ioctl);
+	errno_cache = errno;
+	ASSERT_EQ(rc, -1);
+	ASSERT_EQ(errno_cache, EFAULT);
+
+	self->uvio_ioctl.argument_addr = self->fault_page;
+	rc = ioctl(self->uv_fd, variant->ioctl_cmd, &self->uvio_ioctl);
+	errno_cache = errno;
+	ASSERT_EQ(rc, -1);
+	ASSERT_EQ(errno_cache, EFAULT);
+}
+
+/*
+ * Test to verify that IOCTLs with invalid values in the ioctl_control block
+ * are rejected.
+ */
+TEST_F(uvio_fixture, inval_ioctl_cb)
+{
+	int rc, errno_cache;
+
+	self->uvio_ioctl.argument_len = 0;
+	rc = ioctl(self->uv_fd, variant->ioctl_cmd, &self->uvio_ioctl);
+	errno_cache = errno;
+	ASSERT_EQ(rc, -1);
+	ASSERT_EQ(errno_cache, EINVAL);
+
+	self->uvio_ioctl.argument_len = (uint32_t)-1;
+	rc = ioctl(self->uv_fd, variant->ioctl_cmd, &self->uvio_ioctl);
+	errno_cache = errno;
+	ASSERT_EQ(rc, -1);
+	ASSERT_EQ(errno_cache, EINVAL);
+	self->uvio_ioctl.argument_len = variant->arg_size;
+
+	self->uvio_ioctl.flags = (uint32_t)-1;
+	rc = ioctl(self->uv_fd, variant->ioctl_cmd, &self->uvio_ioctl);
+	errno_cache = errno;
+	ASSERT_EQ(rc, -1);
+	ASSERT_EQ(errno_cache, EINVAL);
+	self->uvio_ioctl.flags = 0;
+
+	memset(self->uvio_ioctl.reserved14, 0xff, sizeof(self->uvio_ioctl.reserved14));
+	rc = ioctl(self->uv_fd, variant->ioctl_cmd, &self->uvio_ioctl);
+	errno_cache = errno;
+	ASSERT_EQ(rc, -1);
+	ASSERT_EQ(errno_cache, EINVAL);
+
+	memset(&self->uvio_ioctl, 0x11, sizeof(self->uvio_ioctl));
+	rc = ioctl(self->uv_fd, variant->ioctl_cmd, &self->uvio_ioctl);
+	ASSERT_EQ(rc, -1);
+}
+
+TEST_F(uvio_fixture, inval_ioctl_cmd)
+{
+	int rc, errno_cache;
+	uint8_t nr = _IOC_NR(variant->ioctl_cmd);
+	unsigned long cmds[] = {
+		_IOWR('a', nr, struct uvio_ioctl_cb),
+		_IOWR(UVIO_TYPE_UVC, nr, int),
+		_IO(UVIO_TYPE_UVC, nr),
+		_IOR(UVIO_TYPE_UVC, nr, struct uvio_ioctl_cb),
+		_IOW(UVIO_TYPE_UVC, nr, struct uvio_ioctl_cb),
+	};
+
+	for (size_t i = 0; i < ARRAY_SIZE(cmds); i++) {
+		rc = ioctl(self->uv_fd, cmds[i], &self->uvio_ioctl);
+		errno_cache = errno;
+		ASSERT_EQ(rc, -1);
+		ASSERT_EQ(errno_cache, ENOTTY);
+	}
+}
+
+struct test_attest_buffer {
+	uint8_t arcb[0x180];
+	uint8_t meas[64];
+	uint8_t add[32];
+};
+
+FIXTURE(attest_fixture) {
+	int uv_fd;
+	struct uvio_ioctl_cb uvio_ioctl;
+	struct uvio_attest uvio_attest;
+	struct test_attest_buffer attest_buffer;
+	__u64 fault_page;
+};
+
+FIXTURE_SETUP(attest_fixture)
+{
+	self->uv_fd = open(UV_PATH, O_ACCMODE);
+
+	self->uvio_ioctl.argument_addr = (__u64)&self->uvio_attest;
+	self->uvio_ioctl.argument_len = sizeof(self->uvio_attest);
+
+	self->uvio_attest.arcb_addr = (__u64)&self->attest_buffer.arcb;
+	self->uvio_attest.arcb_len = sizeof(self->attest_buffer.arcb);
+
+	self->uvio_attest.meas_addr = (__u64)&self->attest_buffer.meas;
+	self->uvio_attest.meas_len = sizeof(self->attest_buffer.meas);
+
+	self->uvio_attest.add_data_addr = (__u64)&self->attest_buffer.add;
+	self->uvio_attest.add_data_len = sizeof(self->attest_buffer.add);
+	self->fault_page =
+		(__u64)mmap(NULL, (size_t)getpagesize(), PROT_NONE, MAP_ANONYMOUS, -1, 0);
+}
+
+FIXTURE_TEARDOWN(attest_fixture)
+{
+	if (self->uv_fd)
+		close(self->uv_fd);
+	munmap((void *)self->fault_page, (size_t)getpagesize());
+}
+
+static void att_inval_sizes_test(uint32_t *size, uint32_t max_size, bool test_zero,
+				 struct __test_metadata *_metadata,
+				 FIXTURE_DATA(attest_fixture) *self)
+{
+	int rc, errno_cache;
+	uint32_t tmp = *size;
+
+	if (test_zero) {
+		*size = 0;
+		rc = ioctl(self->uv_fd, UVIO_IOCTL_ATT, &self->uvio_ioctl);
+		errno_cache = errno;
+		ASSERT_EQ(rc, -1);
+		ASSERT_EQ(errno_cache, EINVAL);
+	}
+	*size = max_size + 1;
+	rc = ioctl(self->uv_fd, UVIO_IOCTL_ATT, &self->uvio_ioctl);
+	errno_cache = errno;
+	ASSERT_EQ(rc, -1);
+	ASSERT_EQ(errno_cache, EINVAL);
+	*size = tmp;
+}
+
+/*
+ * Test to verify that attestation IOCTLs with invalid values in the UVIO
+ * attestation control block are rejected.
+ */
+TEST_F(attest_fixture, att_inval_request)
+{
+	int rc, errno_cache;
+
+	att_inval_sizes_test(&self->uvio_attest.add_data_len, UVIO_ATT_ADDITIONAL_MAX_LEN,
+			     false, _metadata, self);
+	att_inval_sizes_test(&self->uvio_attest.meas_len, UVIO_ATT_MEASUREMENT_MAX_LEN,
+			     true, _metadata, self);
+	att_inval_sizes_test(&self->uvio_attest.arcb_len, UVIO_ATT_ARCB_MAX_LEN,
+			     true, _metadata, self);
+
+	self->uvio_attest.reserved136 = (uint16_t)-1;
+	rc = ioctl(self->uv_fd, UVIO_IOCTL_ATT, &self->uvio_ioctl);
+	errno_cache = errno;
+	ASSERT_EQ(rc, -1);
+	ASSERT_EQ(errno_cache, EINVAL);
+
+	memset(&self->uvio_attest, 0x11, sizeof(self->uvio_attest));
+	rc = ioctl(self->uv_fd, UVIO_IOCTL_ATT, &self->uvio_ioctl);
+	ASSERT_EQ(rc, -1);
+}
+
+static void att_inval_addr_test(__u64 *addr, struct __test_metadata *_metadata,
+				FIXTURE_DATA(attest_fixture) *self)
+{
+	int rc, errno_cache;
+	__u64 tmp = *addr;
+
+	*addr = 0;
+	rc = ioctl(self->uv_fd, UVIO_IOCTL_ATT, &self->uvio_ioctl);
+	errno_cache = errno;
+	ASSERT_EQ(rc, -1);
+	ASSERT_EQ(errno_cache, EFAULT);
+	*addr = self->fault_page;
+	rc = ioctl(self->uv_fd, UVIO_IOCTL_ATT, &self->uvio_ioctl);
+	errno_cache = errno;
+	ASSERT_EQ(rc, -1);
+	ASSERT_EQ(errno_cache, EFAULT);
+	*addr = tmp;
+}
+
+TEST_F(attest_fixture, att_inval_addr)
+{
+	att_inval_addr_test(&self->uvio_attest.arcb_addr, _metadata, self);
+	att_inval_addr_test(&self->uvio_attest.add_data_addr, _metadata, self);
+	att_inval_addr_test(&self->uvio_attest.meas_addr, _metadata, self);
+}
+
+static void __attribute__((constructor)) __constructor_order_last(void)
+{
+	if (!__constructor_order)
+		__constructor_order = _CONSTRUCTOR_ORDER_BACKWARD;
+}
+
+int main(int argc, char **argv)
+{
+	int fd = open(UV_PATH, O_ACCMODE);
+
+	if (fd < 0)
+		ksft_exit_skip("No uv-device or cannot access " UV_PATH  "\n"
+			       "Enable CONFIG_S390_UV_UAPI and check the access rights on "
+			       UV_PATH ".\n");
+	close(fd);
+	return test_harness_run(argc, argv);
+}