This series adds an Ultravisor(UV) device letting the userspace send some
Ultravisor calls to the UV. Currently two calls are supported.
Query Ultravisor Information (QUI) and
Receive Attestation Measurement (Attest[ation]).
The UV device is implemented as a miscdevice accepting only IOCTLs.
The IOCTL cmd specifies the UV call and the IOCTL arg the request
and response data depending on the UV call.
The device driver writes the UV response in the ioctl argument data.
The 'uvdevice' does no checks on the request beside faulty userspace
addresses, if sizes are in a sane range before allocating in kernel space,
and other tests that prevent the system from corruption.
Especially, no checks are made, that will be performed by the UV anyway
(E.g. 'invalid command' in case of attestation on unsupported hardware).
These errors are reported back to Userspace using the UV return code
field.
The first two patches introduce the new device as a module configured to be
compiled directly into the kernel (y) similar to the s390 SCLP and CHSH
miscdevice modules. Patch 3&4 introduce Kselftests which verify error
paths of the ioctl.
v2->v3:
The main change is that QUI is now introduced after Attestation as we
might not want pick it. Also the Kselftest patch is splitted into
Attestation and QUI so that they can be picked without requiring
QUI support of the uvdevice.
* dropped the Kconfig dependency
* reorganized the series:
- Patch 1 now covers the introduction of the uvdevice and Attestation
- Patch 2 adds QUI to uvdevice
- Patch 3/4 add Kselftests for Attestation and QUI
* fixed some nits
* added some comments
v1->v2:
* ioctl returns -ENOIOCTLCMD in case of a invalid ioctl command
* streamlined reserved field test
* default Kconfig is y instead of m
* improved selftest documentation
Steffen Eiden (4):
drivers/s390/char: Add Ultravisor io device
drivers/s390/char: Add Query Ultravisor Information to uvdevice
selftests: drivers/s390x: Add uvdevice tests
selftests: drivers/s390x: Add uvdevice QUI tests
MAINTAINERS | 3 +
arch/s390/include/asm/uv.h | 23 +-
arch/s390/include/uapi/asm/uvdevice.h | 53 +++
drivers/s390/char/Kconfig | 10 +
drivers/s390/char/Makefile | 1 +
drivers/s390/char/uvdevice.c | 320 ++++++++++++++++++
tools/testing/selftests/Makefile | 1 +
tools/testing/selftests/drivers/.gitignore | 1 +
.../selftests/drivers/s390x/uvdevice/Makefile | 22 ++
.../selftests/drivers/s390x/uvdevice/config | 1 +
.../drivers/s390x/uvdevice/test_uvdevice.c | 281 +++++++++++++++
11 files changed, 715 insertions(+), 1 deletion(-)
create mode 100644 arch/s390/include/uapi/asm/uvdevice.h
create mode 100644 drivers/s390/char/uvdevice.c
create mode 100644 tools/testing/selftests/drivers/s390x/uvdevice/Makefile
create mode 100644 tools/testing/selftests/drivers/s390x/uvdevice/config
create mode 100644 tools/testing/selftests/drivers/s390x/uvdevice/test_uvdevice.c
--
2.25.1
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 <[email protected]>
Acked-by: Janosch Frank <[email protected]>
---
MAINTAINERS | 1 +
tools/testing/selftests/Makefile | 1 +
tools/testing/selftests/drivers/.gitignore | 1 +
.../selftests/drivers/s390x/uvdevice/Makefile | 22 ++
.../selftests/drivers/s390x/uvdevice/config | 1 +
.../drivers/s390x/uvdevice/test_uvdevice.c | 276 ++++++++++++++++++
6 files changed, 302 insertions(+)
create mode 100644 tools/testing/selftests/drivers/s390x/uvdevice/Makefile
create mode 100644 tools/testing/selftests/drivers/s390x/uvdevice/config
create mode 100644 tools/testing/selftests/drivers/s390x/uvdevice/test_uvdevice.c
diff --git a/MAINTAINERS b/MAINTAINERS
index f32e876f45c2..7fdf0fa006db 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10582,6 +10582,7 @@ F: arch/s390/kernel/uv.c
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/
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index d08fe4cfe811..d454faf936c3 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -10,6 +10,7 @@ TARGETS += core
TARGETS += cpufreq
TARGETS += cpu-hotplug
TARGETS += drivers/dma-buf
+TARGETS += drivers/s390x/uvdevice
TARGETS += efivarfs
TARGETS += exec
TARGETS += filesystems
diff --git a/tools/testing/selftests/drivers/.gitignore b/tools/testing/selftests/drivers/.gitignore
index ca74f2e1c719..09e23b5afa96 100644
--- a/tools/testing/selftests/drivers/.gitignore
+++ b/tools/testing/selftests/drivers/.gitignore
@@ -1,2 +1,3 @@
# SPDX-License-Identifier: GPL-2.0-only
/dma-buf/udmabuf
+/s390x/uvdevice/test_uvdevice
diff --git a/tools/testing/selftests/drivers/s390x/uvdevice/Makefile b/tools/testing/selftests/drivers/s390x/uvdevice/Makefile
new file mode 100644
index 000000000000..5e701d2708d4
--- /dev/null
+++ b/tools/testing/selftests/drivers/s390x/uvdevice/Makefile
@@ -0,0 +1,22 @@
+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
diff --git a/tools/testing/selftests/drivers/s390x/uvdevice/config b/tools/testing/selftests/drivers/s390x/uvdevice/config
new file mode 100644
index 000000000000..f28a04b99eff
--- /dev/null
+++ b/tools/testing/selftests/drivers/s390x/uvdevice/config
@@ -0,0 +1 @@
+CONFIG_S390_UV_UAPI=y
diff --git a/tools/testing/selftests/drivers/s390x/uvdevice/test_uvdevice.c b/tools/testing/selftests/drivers/s390x/uvdevice/test_uvdevice.c
new file mode 100644
index 000000000000..ea0cdc37b44f
--- /dev/null
+++ b/tools/testing/selftests/drivers/s390x/uvdevice/test_uvdevice.c
@@ -0,0 +1,276 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * selftest for the Ultravisor UAPI device
+ *
+ * Copyright IBM Corp. 2022
+ * Author(s): Steffen Eiden <[email protected]>
+ */
+
+#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);
+}
--
2.25.1
On 3/4/22 15:11, Steffen Eiden wrote:
> This series adds an Ultravisor(UV) device letting the userspace send some
> Ultravisor calls to the UV. Currently two calls are supported.
> Query Ultravisor Information (QUI) and
> Receive Attestation Measurement (Attest[ation]).
>
> The UV device is implemented as a miscdevice accepting only IOCTLs.
> The IOCTL cmd specifies the UV call and the IOCTL arg the request
> and response data depending on the UV call.
> The device driver writes the UV response in the ioctl argument data.
>
> The 'uvdevice' does no checks on the request beside faulty userspace
> addresses, if sizes are in a sane range before allocating in kernel space,
> and other tests that prevent the system from corruption.
> Especially, no checks are made, that will be performed by the UV anyway
> (E.g. 'invalid command' in case of attestation on unsupported hardware).
> These errors are reported back to Userspace using the UV return code
> field.
>
> The first two patches introduce the new device as a module configured to be
> compiled directly into the kernel (y) similar to the s390 SCLP and CHSH
> miscdevice modules. Patch 3&4 introduce Kselftests which verify error
> paths of the ioctl.
Please fixup the commit message in the first patch and then push patches
#1 and #3 to devel so we get CI coverage.
For now I'd opt to not include the qui patches but please put them on a
branch. They might prove to be useful at a later time.
>
> v2->v3:
> The main change is that QUI is now introduced after Attestation as we
> might not want pick it. Also the Kselftest patch is splitted into
> Attestation and QUI so that they can be picked without requiring
> QUI support of the uvdevice.
>
> * dropped the Kconfig dependency
> * reorganized the series:
> - Patch 1 now covers the introduction of the uvdevice and Attestation
> - Patch 2 adds QUI to uvdevice
> - Patch 3/4 add Kselftests for Attestation and QUI
> * fixed some nits
> * added some comments
>
> v1->v2:
> * ioctl returns -ENOIOCTLCMD in case of a invalid ioctl command
> * streamlined reserved field test
> * default Kconfig is y instead of m
> * improved selftest documentation
>
> Steffen Eiden (4):
> drivers/s390/char: Add Ultravisor io device
> drivers/s390/char: Add Query Ultravisor Information to uvdevice
> selftests: drivers/s390x: Add uvdevice tests
> selftests: drivers/s390x: Add uvdevice QUI tests
>
> MAINTAINERS | 3 +
> arch/s390/include/asm/uv.h | 23 +-
> arch/s390/include/uapi/asm/uvdevice.h | 53 +++
> drivers/s390/char/Kconfig | 10 +
> drivers/s390/char/Makefile | 1 +
> drivers/s390/char/uvdevice.c | 320 ++++++++++++++++++
> tools/testing/selftests/Makefile | 1 +
> tools/testing/selftests/drivers/.gitignore | 1 +
> .../selftests/drivers/s390x/uvdevice/Makefile | 22 ++
> .../selftests/drivers/s390x/uvdevice/config | 1 +
> .../drivers/s390x/uvdevice/test_uvdevice.c | 281 +++++++++++++++
> 11 files changed, 715 insertions(+), 1 deletion(-)
> create mode 100644 arch/s390/include/uapi/asm/uvdevice.h
> create mode 100644 drivers/s390/char/uvdevice.c
> create mode 100644 tools/testing/selftests/drivers/s390x/uvdevice/Makefile
> create mode 100644 tools/testing/selftests/drivers/s390x/uvdevice/config
> create mode 100644 tools/testing/selftests/drivers/s390x/uvdevice/test_uvdevice.c
>