Add a selftest exercising the vfio-pci DSN handling: - the serial number is scrubbed to zero by default while the DSN capability remains present, - guest writes to the DSN bytes are rejected (value unchanged), - VFIO_DEVICE_FEATURE_PCI_DSN PROBE reflects DSN support, - SET/GET round-trips and is reflected in the guest-visible config space, - SET twice returns the latest value on GET, - the presented serial persists across a device reset, and - a short argsz is rejected with -EINVAL.
The tests skip when the assigned device has no DSN capability or does not support reset. Run with the device assigned to vfio-pci, e.g.: VFIO_SELFTESTS_BDF="0000:01:00.0" ./vfio_pci_dsn_test Exercised under QEMU with full VFIO assignment via IOMMUFD: all of the test's cases passed on x86_64 (intel-iommu) and arm64 (smmuv3) against an emulated e1000e (which implements DSN), and on x86_64 against an SR-IOV VF that implements DSN in an AER -> ARI -> DSN extended-capability chain. The SR-IOV run used a KASAN + PROVE_LOCKING kernel with no reports. Signed-off-by: Pranjal Arya <[email protected]> --- MAINTAINERS | 6 + tools/testing/selftests/vfio/Makefile | 1 + tools/testing/selftests/vfio/vfio_pci_dsn_test.c | 206 +++++++++++++++++++++++ 3 files changed, 213 insertions(+) diff --git a/MAINTAINERS b/MAINTAINERS index 8629ed2aa82f..ed8e7df12021 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -28347,6 +28347,12 @@ L: [email protected] S: Supported F: drivers/vfio/pci/nvgrace-gpu/ +VFIO PCI DEVICE SERIAL NUMBER SELFTEST +M: Pranjal Arya <[email protected]> +L: [email protected] +S: Maintained +F: tools/testing/selftests/vfio/vfio_pci_dsn_test.c + VFIO PCI DEVICE SPECIFIC DRIVERS R: Jason Gunthorpe <[email protected]> R: Yishai Hadas <[email protected]> diff --git a/tools/testing/selftests/vfio/Makefile b/tools/testing/selftests/vfio/Makefile index e6e8cb52ab03..06e637573cf7 100644 --- a/tools/testing/selftests/vfio/Makefile +++ b/tools/testing/selftests/vfio/Makefile @@ -13,6 +13,7 @@ TEST_GEN_PROGS += vfio_pci_device_test TEST_GEN_PROGS += vfio_pci_device_init_perf_test TEST_GEN_PROGS += vfio_pci_driver_test TEST_GEN_PROGS += vfio_pci_sriov_uapi_test +TEST_GEN_PROGS += vfio_pci_dsn_test TEST_FILES += scripts/cleanup.sh TEST_FILES += scripts/lib.sh diff --git a/tools/testing/selftests/vfio/vfio_pci_dsn_test.c b/tools/testing/selftests/vfio/vfio_pci_dsn_test.c new file mode 100644 index 000000000000..d7652ad725f4 --- /dev/null +++ b/tools/testing/selftests/vfio/vfio_pci_dsn_test.c @@ -0,0 +1,206 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Tests for the PCIe Device Serial Number (DSN) handling in vfio-pci: + * - the physical serial is scrubbed (read as zero) by default, + * - guest writes to the DSN bytes are rejected (no change), and + * - VFIO_DEVICE_FEATURE_PCI_DSN can probe/set/get the presented serial. + */ +#include <errno.h> +#include <fcntl.h> +#include <stdlib.h> +#include <string.h> + +#include <sys/ioctl.h> + +#include <linux/limits.h> +#include <linux/pci_regs.h> +#include <linux/vfio.h> + +#include <libvfio.h> + +#include "kselftest_harness.h" + +static const char *device_bdf; + +/* Walk the extended capability chain and return the DSN cap offset, or 0. */ +static u16 find_dsn_cap(struct vfio_pci_device *device) +{ + u16 pos = PCI_CFG_SPACE_SIZE; + int loops = (PCI_CFG_SPACE_EXP_SIZE - PCI_CFG_SPACE_SIZE) / + PCI_CAP_SIZEOF; + + while (pos >= PCI_CFG_SPACE_SIZE && loops--) { + u32 header = vfio_pci_config_readl(device, pos); + + if (!header) + break; + + if (PCI_EXT_CAP_ID(header) == PCI_EXT_CAP_ID_DSN) + return pos; + + pos = PCI_EXT_CAP_NEXT(header); + } + + return 0; +} + +/* + * Issue the DSN device feature. @serial may be NULL for PROBE (no data is + * read or written in that case); for GET/SET it is required. + */ +static int dsn_feature(struct vfio_pci_device *device, u32 op, u64 *serial) +{ + u8 buf[sizeof(struct vfio_device_feature) + + sizeof(struct vfio_device_feature_pci_dsn)] = {}; + struct vfio_device_feature *feature = (void *)buf; + struct vfio_device_feature_pci_dsn *dsn = (void *)feature->data; + + feature->argsz = sizeof(buf); + feature->flags = op | VFIO_DEVICE_FEATURE_PCI_DSN; + + if ((op & VFIO_DEVICE_FEATURE_SET) && serial) + dsn->serial_number = *serial; + + if (ioctl(device->fd, VFIO_DEVICE_FEATURE, feature)) + return -errno; + + if ((op & VFIO_DEVICE_FEATURE_GET) && serial) + *serial = dsn->serial_number; + + return 0; +} + +FIXTURE(vfio_pci_dsn_test) { + struct iommu *iommu; + struct vfio_pci_device *device; + u16 dsn_pos; +}; + +FIXTURE_SETUP(vfio_pci_dsn_test) +{ + self->iommu = iommu_init(default_iommu_mode); + self->device = vfio_pci_device_init(device_bdf, self->iommu); + self->dsn_pos = find_dsn_cap(self->device); +} + +FIXTURE_TEARDOWN(vfio_pci_dsn_test) +{ + vfio_pci_device_cleanup(self->device); + iommu_cleanup(self->iommu); +} + +/* The physical serial number must not be visible; reads must be zero. */ +TEST_F(vfio_pci_dsn_test, serial_scrubbed) +{ + if (!self->dsn_pos) + SKIP(return, "Device has no DSN capability\n"); + + ASSERT_EQ(0, vfio_pci_config_readl(self->device, self->dsn_pos + PCI_DSN_LOW_DW)); + ASSERT_EQ(0, vfio_pci_config_readl(self->device, self->dsn_pos + PCI_DSN_HIGH_DW)); + + /* The capability header itself must still be present. */ + ASSERT_EQ(PCI_EXT_CAP_ID_DSN, + PCI_EXT_CAP_ID(vfio_pci_config_readl(self->device, + self->dsn_pos))); +} + +/* Guest writes to the DSN bytes must be ignored (read-only state). */ +TEST_F(vfio_pci_dsn_test, write_rejected) +{ + if (!self->dsn_pos) + SKIP(return, "Device has no DSN capability\n"); + + vfio_pci_config_writel(self->device, self->dsn_pos + PCI_DSN_LOW_DW, 0xdeadbeef); + vfio_pci_config_writel(self->device, self->dsn_pos + PCI_DSN_HIGH_DW, 0xcafef00d); + + ASSERT_EQ(0, vfio_pci_config_readl(self->device, self->dsn_pos + PCI_DSN_LOW_DW)); + ASSERT_EQ(0, vfio_pci_config_readl(self->device, self->dsn_pos + PCI_DSN_HIGH_DW)); +} + +/* PROBE must succeed iff the device has a DSN capability. */ +TEST_F(vfio_pci_dsn_test, probe) +{ + /* PROBE must include at least one supported op flag to pass. */ + int ret = dsn_feature(self->device, + VFIO_DEVICE_FEATURE_PROBE | + VFIO_DEVICE_FEATURE_GET | + VFIO_DEVICE_FEATURE_SET, NULL); + + if (!self->dsn_pos) + ASSERT_EQ(-ENOTTY, ret); + else + ASSERT_EQ(0, ret); +} + +/* SET then GET must round-trip, and the guest-visible bytes must match. */ +TEST_F(vfio_pci_dsn_test, set_get_roundtrip) +{ + u64 want = 0x0123456789abcdefULL; + u64 got = 0; + + if (!self->dsn_pos) + SKIP(return, "Device has no DSN capability\n"); + + ASSERT_EQ(0, dsn_feature(self->device, VFIO_DEVICE_FEATURE_SET, &want)); + ASSERT_EQ(0, dsn_feature(self->device, VFIO_DEVICE_FEATURE_GET, &got)); + ASSERT_EQ(want, got); + + ASSERT_EQ((u32)want, + vfio_pci_config_readl(self->device, self->dsn_pos + PCI_DSN_LOW_DW)); + ASSERT_EQ((u32)(want >> 32), + vfio_pci_config_readl(self->device, self->dsn_pos + PCI_DSN_HIGH_DW)); +} + +/* SET twice; GET must return the latest value. */ +TEST_F(vfio_pci_dsn_test, set_twice) +{ + u64 first = 0x1111222233334444ULL; + u64 second = 0xaaaabbbbccccddddULL; + u64 got = 0; + + if (!self->dsn_pos) + SKIP(return, "Device has no DSN capability\n"); + + ASSERT_EQ(0, dsn_feature(self->device, VFIO_DEVICE_FEATURE_SET, &first)); + ASSERT_EQ(0, dsn_feature(self->device, VFIO_DEVICE_FEATURE_SET, &second)); + ASSERT_EQ(0, dsn_feature(self->device, VFIO_DEVICE_FEATURE_GET, &got)); + ASSERT_EQ(second, got); +} + +/* The presented serial persists across a device reset (FLR/SBR). */ +TEST_F(vfio_pci_dsn_test, persists_across_reset) +{ + u64 want = 0x5555666677778888ULL; + u64 got = 0; + + if (!self->dsn_pos) + SKIP(return, "Device has no DSN capability\n"); + if (!(self->device->info.flags & VFIO_DEVICE_FLAGS_RESET)) + SKIP(return, "Device does not support reset\n"); + + ASSERT_EQ(0, dsn_feature(self->device, VFIO_DEVICE_FEATURE_SET, &want)); + vfio_pci_device_reset(self->device); + ASSERT_EQ(0, dsn_feature(self->device, VFIO_DEVICE_FEATURE_GET, &got)); + ASSERT_EQ(want, got); +} + +/* A short argsz must be rejected with -EINVAL. */ +TEST_F(vfio_pci_dsn_test, bad_argsz) +{ + struct vfio_device_feature feature = { + .argsz = sizeof(struct vfio_device_feature), + .flags = VFIO_DEVICE_FEATURE_GET | VFIO_DEVICE_FEATURE_PCI_DSN, + }; + + if (!self->dsn_pos) + SKIP(return, "Device has no DSN capability\n"); + + ASSERT_EQ(-1, ioctl(self->device->fd, VFIO_DEVICE_FEATURE, &feature)); + ASSERT_EQ(EINVAL, errno); +} + +int main(int argc, char *argv[]) +{ + device_bdf = vfio_selftests_get_bdf(&argc, argv); + return test_harness_run(argc, argv); +} -- 2.34.1
