[PATCH v6 0/8] vfio: selftest: Add SR-IOV UAPI test

[PATCH v6 0/8] vfio: selftest: Add SR-IOV UAPI test

[Raghavendra Rao Ananta]

Hello,

This series adds a vfio selftest, vfio_pci_sriov_uapi_test.c, to get some
coverage on SR-IOV UAPI handling. Specifically, it includes the
following cases that iterates over all the iommu modes:
 - Setting correct/incorrect/NULL tokens during device init.
 - Close the PF device immediately after setting the token.
 - Change/override the PF's token after device init.

The test takes care of creating/setting up the VF device, and hence, it
can be executed like any other test, simply by passing the PF's BDF to
run.sh. For example,

$ ./scripts/setup.sh 0000:16:00.1
$ ./scripts/run.sh ./vfio_pci_sriov_uapi_test

TAP version 13
1..45
# Starting 45 tests from 15 test cases.
#  RUN           vfio_pci_sriov_uapi_test.vfio_type1_iommu_same_uuid.init_token_match ...
Created 1 VF (0000:1a:00.0) under the PF: 0000:16:00.1
#            OK  vfio_pci_sriov_uapi_test.vfio_type1_iommu_same_uuid.init_token_match
ok 1 vfio_pci_sriov_uapi_test.vfio_type1_iommu_same_uuid.init_token_match
#  RUN           vfio_pci_sriov_uapi_test.vfio_type1_iommu_same_uuid.pf_early_close ...
Created 1 VF (0000:1a:00.0) under the PF: 0000:16:00.1
#            OK  vfio_pci_sriov_uapi_test.vfio_type1_iommu_same_uuid.pf_early_close
ok 2 vfio_pci_sriov_uapi_test.vfio_type1_iommu_same_uuid.pf_early_close
[...]
#  RUN           vfio_pci_sriov_uapi_test.iommufd_null_uuid.override_token ...
Created 1 VF (0000:1a:00.0) under the PF: 0000:16:00.1
#            OK  vfio_pci_sriov_uapi_test.iommufd_null_uuid.override_token
ok 45 vfio_pci_sriov_uapi_test.iommufd_null_uuid.override_token
# PASSED: 45 / 45 tests passed.
# Totals: pass:45 fail:0 xfail:0 xpass:0 skip:0 error:0

Thank you.
Raghavendra

v6:
- Terminate the output buffers of readlink() with '\0' in sysfs.c.

v5:
- Rebase to v7.0-rc1 (Alex).

v4: Suggestions by David and Alex
- Assert that the value computed in sysfs_val_get() in an int. Rename the
  function to sysfs_val_get_int() to better reflect what the function is doing. (Alex)
- Add the missing Signed-off-by tag in patch-7 (David).

v3: Suggestions by David Matlack (thanks!)
- Introduce a patch to add -Wall and -Werror to the vfio Makefile.
- Use snprintf_assert() where they were missed.
- Rename the functions as suggested in the sysfs lib and the test file.
- Alloc the output char * buffer in the functions sysfs_driver_get() and
  sysfs_sriov_vf_bdf_get() instead of relying on the caller to pass one.
  The caller is now responsible for freeing these buffers.
- Remove unnecessary initializations of local variables in sysfs and the
  vfio_pci_device libraries.
- Move the inclusion of -luuid to the top level Makefile.
- Introduce vfio_pci_device_{alloc|free}() and let the test and the functions in
  vfio_pci_device.c use this.
- Return -errno for the ioctl failure in __vfio_device_bind_iommufd() instead of
  directly calling ioctl_assert().
- Since the vfio-pci driver sets the 'driver_override' to the driver of PF,
  instead of clearing sriov_drivers_autoprobe and binding the VF explicitly to
  the 'vfio-pci' driver, only assert that it's already bound.
- By extension to the above point, remove the unnecessary functions from the sysfs
  lib.

v2: Suggestions by David Matlack (thank you)
 - Introduce snprintf_assert() to check against content trucation.
 - Introduce a new sysfs library to handle all the common vfio/pci sysfs
   operations.
 - Rename vfio_pci_container_get_device_fd() to
   vfio_pci_group_get_device_fd().
 - Use a fixed size 'arg' array instead of dynamic allocation in
   __vfio_pci_group_get_device_fd().
 - Exclude vfio_pci_device_init() to accept the 'vf_token' arg.
 - Move the vfio_pci_sriov_uapi_test.c global variable to the FIXTURE()
   struct or as TEST_F() local variables.
 - test_vfio_pci_container_setup() returns 'int' to indicate status.
 - Skip the test if nr_vfs != 0.
 - Explicitly set "sriov_drivers_autoprobe" for the PF.
 - Make sure to bind the VF device to the "vfio-pci" driver.
 - Cleanup the things done by FIXTURE_SETUP() in FIXTURE_TEARDOWN().

v5: https://lore.kernel.org/all/20260227233928.84530-1-rananta@google.com/
v4: https://lore.kernel.org/all/20260224182532.3914470-1-rananta@google.com/
v3: https://lore.kernel.org/all/20260204010057.1079647-1-rananta@google.com/
v2: https://lore.kernel.org/all/20251210181417.3677674-1-rananta@google.com/
v1: https://lore.kernel.org/all/20251104003536.3601931-1-rananta@google.com/

Raghavendra Rao Ananta (8):
  vfio: selftests: Add -Wall and -Werror to the Makefile
  vfio: selftests: Introduce snprintf_assert()
  vfio: selftests: Introduce a sysfs lib
  vfio: selftests: Extend container/iommufd setup for passing vf_token
  vfio: selftests: Expose more vfio_pci_device functions
  vfio: selftests: Add helper to set/override a vf_token
  vfio: selftests: Add helpers to alloc/free vfio_pci_device
  vfio: selftests: Add tests to validate SR-IOV UAPI

 tools/testing/selftests/vfio/Makefile         |   4 +
 .../selftests/vfio/lib/include/libvfio.h      |   1 +
 .../vfio/lib/include/libvfio/assert.h         |   5 +
 .../vfio/lib/include/libvfio/sysfs.h          |  12 ++
 .../lib/include/libvfio/vfio_pci_device.h     |  11 +
 tools/testing/selftests/vfio/lib/libvfio.mk   |   1 +
 tools/testing/selftests/vfio/lib/sysfs.c      | 144 +++++++++++++
 .../selftests/vfio/lib/vfio_pci_device.c      | 157 ++++++++++----
 .../selftests/vfio/vfio_dma_mapping_test.c    |   6 +-
 .../selftests/vfio/vfio_pci_device_test.c     |  21 +-
 .../selftests/vfio/vfio_pci_sriov_uapi_test.c | 200 ++++++++++++++++++
 11 files changed, 511 insertions(+), 51 deletions(-)
 create mode 100644 tools/testing/selftests/vfio/lib/include/libvfio/sysfs.h
 create mode 100644 tools/testing/selftests/vfio/lib/sysfs.c
 create mode 100644 tools/testing/selftests/vfio/vfio_pci_sriov_uapi_test.c


base-commit: 6de23f81a5e08be8fbf5e8d7e9febc72a5b5f27f
--
2.53.0.473.g4a7958ca14-goog

[PATCH v6 1/8] vfio: selftests: Add -Wall and -Werror to the Makefile

[Raghavendra Rao Ananta]

Add the compiler flags, -Wall and -Werror, to catch all the build
warnings and flag them as a build error, respectively. This is to
ensure that no obvious programmer errors are introduced. We can
add -Wno-* flags in the future to ignore specific warnings as necesasry.

Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
Reviewed-by: David Matlack <dmatlack@google.com>
---
 tools/testing/selftests/vfio/Makefile | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/testing/selftests/vfio/Makefile b/tools/testing/selftests/vfio/Makefile
index 8e90e409e91d8..6a9ac6dd32cb6 100644
--- a/tools/testing/selftests/vfio/Makefile
+++ b/tools/testing/selftests/vfio/Makefile
@@ -23,6 +23,7 @@ include lib/libvfio.mk
 
 CFLAGS += -I$(top_srcdir)/tools/include
 CFLAGS += -MD
+CFLAGS += -Wall -Werror
 CFLAGS += $(EXTRA_CFLAGS)
 
 LDFLAGS += -pthread
-- 
2.53.0.473.g4a7958ca14-goog

[PATCH v6 2/8] vfio: selftests: Introduce snprintf_assert()

[Raghavendra Rao Ananta]

Introduce snprintf_assert() to protect the users of snprintf() to fail
if the requested operation was truncated due to buffer limits. VFIO
tests and libraries, including a new sysfs library that will be introduced
by an upcoming patch, rely quite heavily on snprintf()s to build PCI
sysfs paths. Having a protection against this will be helpful to prevent
false test failures.

Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
Reviewed-by: David Matlack <dmatlack@google.com>
---
 .../vfio/lib/include/libvfio/assert.h         |  5 +++++
 .../selftests/vfio/lib/vfio_pci_device.c      |  8 +++----
 .../selftests/vfio/vfio_dma_mapping_test.c    |  6 +++---
 .../selftests/vfio/vfio_pci_device_test.c     | 21 ++++++++++---------
 4 files changed, 23 insertions(+), 17 deletions(-)

diff --git a/tools/testing/selftests/vfio/lib/include/libvfio/assert.h b/tools/testing/selftests/vfio/lib/include/libvfio/assert.h
index f4ebd122d9b6f..77b68c7129a64 100644
--- a/tools/testing/selftests/vfio/lib/include/libvfio/assert.h
+++ b/tools/testing/selftests/vfio/lib/include/libvfio/assert.h
@@ -51,4 +51,9 @@
 	VFIO_ASSERT_EQ(__ret, 0, "ioctl(%s, %s, %s) returned %d\n", #_fd, #_op, #_arg, __ret); \
 } while (0)
 
+#define snprintf_assert(_s, _size, _fmt, ...) do {                      \
+	int __ret = snprintf(_s, _size, _fmt, ##__VA_ARGS__);           \
+	VFIO_ASSERT_LT(__ret, _size);                                   \
+} while (0)
+
 #endif /* SELFTESTS_VFIO_LIB_INCLUDE_LIBVFIO_ASSERT_H */
diff --git a/tools/testing/selftests/vfio/lib/vfio_pci_device.c b/tools/testing/selftests/vfio/lib/vfio_pci_device.c
index 4e5871f1ebc3b..1538d2b30ae59 100644
--- a/tools/testing/selftests/vfio/lib/vfio_pci_device.c
+++ b/tools/testing/selftests/vfio/lib/vfio_pci_device.c
@@ -209,7 +209,7 @@ static unsigned int vfio_pci_get_group_from_dev(const char *bdf)
 	unsigned int group;
 	int ret;
 
-	snprintf(sysfs_path, PATH_MAX, "%s/%s/iommu_group", PCI_SYSFS_PATH, bdf);
+	snprintf_assert(sysfs_path, PATH_MAX, "%s/%s/iommu_group", PCI_SYSFS_PATH, bdf);
 
 	ret = readlink(sysfs_path, dev_iommu_group_path, sizeof(dev_iommu_group_path));
 	VFIO_ASSERT_NE(ret, -1, "Failed to get the IOMMU group for device: %s\n", bdf);
@@ -229,7 +229,7 @@ static void vfio_pci_group_setup(struct vfio_pci_device *device, const char *bdf
 	int group;
 
 	group = vfio_pci_get_group_from_dev(bdf);
-	snprintf(group_path, sizeof(group_path), "/dev/vfio/%d", group);
+	snprintf_assert(group_path, sizeof(group_path), "/dev/vfio/%d", group);
 
 	device->group_fd = open(group_path, O_RDWR);
 	VFIO_ASSERT_GE(device->group_fd, 0, "open(%s) failed\n", group_path);
@@ -300,7 +300,7 @@ const char *vfio_pci_get_cdev_path(const char *bdf)
 	cdev_path = calloc(PATH_MAX, 1);
 	VFIO_ASSERT_NOT_NULL(cdev_path);
 
-	snprintf(dir_path, sizeof(dir_path), "/sys/bus/pci/devices/%s/vfio-dev/", bdf);
+	snprintf_assert(dir_path, sizeof(dir_path), "/sys/bus/pci/devices/%s/vfio-dev/", bdf);
 
 	dir = opendir(dir_path);
 	VFIO_ASSERT_NOT_NULL(dir, "Failed to open directory %s\n", dir_path);
@@ -310,7 +310,7 @@ const char *vfio_pci_get_cdev_path(const char *bdf)
 		if (strncmp("vfio", entry->d_name, 4))
 			continue;
 
-		snprintf(cdev_path, PATH_MAX, "/dev/vfio/devices/%s", entry->d_name);
+		snprintf_assert(cdev_path, PATH_MAX, "/dev/vfio/devices/%s", entry->d_name);
 		break;
 	}
 
diff --git a/tools/testing/selftests/vfio/vfio_dma_mapping_test.c b/tools/testing/selftests/vfio/vfio_dma_mapping_test.c
index abb170bdcef7e..7d0de8c79de13 100644
--- a/tools/testing/selftests/vfio/vfio_dma_mapping_test.c
+++ b/tools/testing/selftests/vfio/vfio_dma_mapping_test.c
@@ -44,9 +44,9 @@ static int intel_iommu_mapping_get(const char *bdf, u64 iova,
 	FILE *file;
 	char *rest;
 
-	snprintf(iommu_mapping_path, sizeof(iommu_mapping_path),
-		 "/sys/kernel/debug/iommu/intel/%s/domain_translation_struct",
-		 bdf);
+	snprintf_assert(iommu_mapping_path, sizeof(iommu_mapping_path),
+			"/sys/kernel/debug/iommu/intel/%s/domain_translation_struct",
+			bdf);
 
 	printf("Searching for IOVA 0x%lx in %s\n", iova, iommu_mapping_path);
 
diff --git a/tools/testing/selftests/vfio/vfio_pci_device_test.c b/tools/testing/selftests/vfio/vfio_pci_device_test.c
index 7c0fe8ce3a61f..93c11fd5e0818 100644
--- a/tools/testing/selftests/vfio/vfio_pci_device_test.c
+++ b/tools/testing/selftests/vfio/vfio_pci_device_test.c
@@ -39,16 +39,17 @@ FIXTURE_TEARDOWN(vfio_pci_device_test)
 	iommu_cleanup(self->iommu);
 }
 
-#define read_pci_id_from_sysfs(_file) ({							\
-	char __sysfs_path[PATH_MAX];								\
-	char __buf[32];										\
-	int __fd;										\
-												\
-	snprintf(__sysfs_path, PATH_MAX, "/sys/bus/pci/devices/%s/%s", device_bdf, _file);	\
-	ASSERT_GT((__fd = open(__sysfs_path, O_RDONLY)), 0);					\
-	ASSERT_GT(read(__fd, __buf, ARRAY_SIZE(__buf)), 0);					\
-	ASSERT_EQ(0, close(__fd));								\
-	(u16)strtoul(__buf, NULL, 0);								\
+#define read_pci_id_from_sysfs(_file) ({					\
+	char __sysfs_path[PATH_MAX];						\
+	char __buf[32];								\
+	int __fd;								\
+										\
+	snprintf_assert(__sysfs_path, PATH_MAX, "/sys/bus/pci/devices/%s/%s",	\
+			device_bdf, _file);					\
+	ASSERT_GT((__fd = open(__sysfs_path, O_RDONLY)), 0);			\
+	ASSERT_GT(read(__fd, __buf, ARRAY_SIZE(__buf)), 0);			\
+	ASSERT_EQ(0, close(__fd));						\
+	(u16)strtoul(__buf, NULL, 0);						\
 })
 
 TEST_F(vfio_pci_device_test, config_space_read_write)
-- 
2.53.0.473.g4a7958ca14-goog

[PATCH v6 3/8] vfio: selftests: Introduce a sysfs lib

[Raghavendra Rao Ananta]

Introduce a sysfs library to handle the common reads/writes to the
PCI sysfs files, for example, getting the total number of VFs supported
by the device via /sys/bus/pci/devices/$BDF/sriov_totalvfs. The library
will be used in the upcoming test patch to configure the VFs for a given
PF device.

Opportunistically, move vfio_pci_get_group_from_dev() to this library as
it falls under the same bucket. Rename it to sysfs_iommu_group_get() to
align with other function names.

Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
Reviewed-by: David Matlack <dmatlack@google.com>
---
 .../selftests/vfio/lib/include/libvfio.h      |   1 +
 .../vfio/lib/include/libvfio/sysfs.h          |  12 ++
 tools/testing/selftests/vfio/lib/libvfio.mk   |   1 +
 tools/testing/selftests/vfio/lib/sysfs.c      | 144 ++++++++++++++++++
 .../selftests/vfio/lib/vfio_pci_device.c      |  22 +--
 5 files changed, 159 insertions(+), 21 deletions(-)
 create mode 100644 tools/testing/selftests/vfio/lib/include/libvfio/sysfs.h
 create mode 100644 tools/testing/selftests/vfio/lib/sysfs.c

diff --git a/tools/testing/selftests/vfio/lib/include/libvfio.h b/tools/testing/selftests/vfio/lib/include/libvfio.h
index 1b6da54cc2cb7..07862b470777b 100644
--- a/tools/testing/selftests/vfio/lib/include/libvfio.h
+++ b/tools/testing/selftests/vfio/lib/include/libvfio.h
@@ -5,6 +5,7 @@
 #include <libvfio/assert.h>
 #include <libvfio/iommu.h>
 #include <libvfio/iova_allocator.h>
+#include <libvfio/sysfs.h>
 #include <libvfio/vfio_pci_device.h>
 #include <libvfio/vfio_pci_driver.h>
 
diff --git a/tools/testing/selftests/vfio/lib/include/libvfio/sysfs.h b/tools/testing/selftests/vfio/lib/include/libvfio/sysfs.h
new file mode 100644
index 0000000000000..c48d5ef00ba6f
--- /dev/null
+++ b/tools/testing/selftests/vfio/lib/include/libvfio/sysfs.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef SELFTESTS_VFIO_LIB_INCLUDE_LIBVFIO_SYSFS_H
+#define SELFTESTS_VFIO_LIB_INCLUDE_LIBVFIO_SYSFS_H
+
+int sysfs_sriov_totalvfs_get(const char *bdf);
+int sysfs_sriov_numvfs_get(const char *bdf);
+void sysfs_sriov_numvfs_set(const char *bdfs, int numvfs);
+char *sysfs_sriov_vf_bdf_get(const char *pf_bdf, int i);
+unsigned int sysfs_iommu_group_get(const char *bdf);
+char *sysfs_driver_get(const char *bdf);
+
+#endif /* SELFTESTS_VFIO_LIB_INCLUDE_LIBVFIO_SYSFS_H */
diff --git a/tools/testing/selftests/vfio/lib/libvfio.mk b/tools/testing/selftests/vfio/lib/libvfio.mk
index 9f47bceed16f4..b7857319c3f1f 100644
--- a/tools/testing/selftests/vfio/lib/libvfio.mk
+++ b/tools/testing/selftests/vfio/lib/libvfio.mk
@@ -6,6 +6,7 @@ LIBVFIO_SRCDIR := $(selfdir)/vfio/lib
 LIBVFIO_C := iommu.c
 LIBVFIO_C += iova_allocator.c
 LIBVFIO_C += libvfio.c
+LIBVFIO_C += sysfs.c
 LIBVFIO_C += vfio_pci_device.c
 LIBVFIO_C += vfio_pci_driver.c
 
diff --git a/tools/testing/selftests/vfio/lib/sysfs.c b/tools/testing/selftests/vfio/lib/sysfs.c
new file mode 100644
index 0000000000000..1fec6c7a7fce7
--- /dev/null
+++ b/tools/testing/selftests/vfio/lib/sysfs.c
@@ -0,0 +1,144 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <linux/limits.h>
+
+#include <libvfio.h>
+
+static int sysfs_val_get_int(const char *component, const char *name,
+			     const char *file)
+{
+	char path[PATH_MAX];
+	char buf[32];
+	int ret;
+	int fd;
+
+	snprintf_assert(path, PATH_MAX, "/sys/bus/pci/%s/%s/%s", component, name, file);
+	fd = open(path, O_RDONLY);
+	if (fd < 0)
+		return fd;
+
+	VFIO_ASSERT_GT(read(fd, buf, ARRAY_SIZE(buf)), 0);
+	VFIO_ASSERT_EQ(close(fd), 0);
+
+	errno = 0;
+	ret = strtol(buf, NULL, 0);
+	VFIO_ASSERT_EQ(errno, 0, "sysfs path \"%s\" is not an integer: \"%s\"\n", path, buf);
+
+	return ret;
+}
+
+static void sysfs_val_set(const char *component, const char *name,
+			  const char *file, const char *val)
+{
+	char path[PATH_MAX];
+	int fd;
+
+	snprintf_assert(path, PATH_MAX, "/sys/bus/pci/%s/%s/%s", component, name, file);
+	VFIO_ASSERT_GT(fd = open(path, O_WRONLY), 0);
+
+	VFIO_ASSERT_EQ(write(fd, val, strlen(val)), strlen(val));
+	VFIO_ASSERT_EQ(close(fd), 0);
+}
+
+static int sysfs_device_val_get(const char *bdf, const char *file)
+{
+	return sysfs_val_get_int("devices", bdf, file);
+}
+
+static void sysfs_device_val_set(const char *bdf, const char *file, const char *val)
+{
+	sysfs_val_set("devices", bdf, file, val);
+}
+
+static void sysfs_device_val_set_int(const char *bdf, const char *file, int val)
+{
+	char val_str[32];
+
+	snprintf_assert(val_str, sizeof(val_str), "%d", val);
+	sysfs_device_val_set(bdf, file, val_str);
+}
+
+int sysfs_sriov_totalvfs_get(const char *bdf)
+{
+	return sysfs_device_val_get(bdf, "sriov_totalvfs");
+}
+
+int sysfs_sriov_numvfs_get(const char *bdf)
+{
+	return sysfs_device_val_get(bdf, "sriov_numvfs");
+}
+
+void sysfs_sriov_numvfs_set(const char *bdf, int numvfs)
+{
+	sysfs_device_val_set_int(bdf, "sriov_numvfs", numvfs);
+}
+
+char *sysfs_sriov_vf_bdf_get(const char *pf_bdf, int i)
+{
+	char vf_path[PATH_MAX];
+	char path[PATH_MAX];
+	char *out_vf_bdf;
+	int ret;
+
+	out_vf_bdf = calloc(16, sizeof(char));
+	VFIO_ASSERT_NOT_NULL(out_vf_bdf);
+
+	snprintf_assert(path, PATH_MAX, "/sys/bus/pci/devices/%s/virtfn%d", pf_bdf, i);
+
+	ret = readlink(path, vf_path, PATH_MAX);
+	VFIO_ASSERT_NE(ret, -1);
+	vf_path[ret] = '\0';
+
+	ret = sscanf(basename(vf_path), "%s", out_vf_bdf);
+	VFIO_ASSERT_EQ(ret, 1);
+
+	return out_vf_bdf;
+}
+
+unsigned int sysfs_iommu_group_get(const char *bdf)
+{
+	char dev_iommu_group_path[PATH_MAX];
+	char path[PATH_MAX];
+	unsigned int group;
+	int ret;
+
+	snprintf_assert(path, PATH_MAX, "/sys/bus/pci/devices/%s/iommu_group", bdf);
+
+	ret = readlink(path, dev_iommu_group_path, sizeof(dev_iommu_group_path));
+	VFIO_ASSERT_NE(ret, -1, "Failed to get the IOMMU group for device: %s\n", bdf);
+	dev_iommu_group_path[ret] = '\0';
+
+	ret = sscanf(basename(dev_iommu_group_path), "%u", &group);
+	VFIO_ASSERT_EQ(ret, 1, "Failed to get the IOMMU group for device: %s\n", bdf);
+
+	return group;
+}
+
+char *sysfs_driver_get(const char *bdf)
+{
+	char driver_path[PATH_MAX];
+	char path[PATH_MAX];
+	char *out_driver;
+	int ret;
+
+	out_driver = calloc(64, sizeof(char));
+	VFIO_ASSERT_NOT_NULL(out_driver);
+
+	snprintf_assert(path, PATH_MAX, "/sys/bus/pci/devices/%s/driver", bdf);
+	ret = readlink(path, driver_path, PATH_MAX);
+	if (ret == -1) {
+		free(out_driver);
+
+		if (errno == ENOENT)
+			return NULL;
+
+		VFIO_FAIL("Failed to read %s\n", path);
+	}
+	driver_path[ret] = '\0';
+
+	strcpy(out_driver, basename(driver_path));
+	return out_driver;
+}
diff --git a/tools/testing/selftests/vfio/lib/vfio_pci_device.c b/tools/testing/selftests/vfio/lib/vfio_pci_device.c
index 1538d2b30ae59..82f255f0486dc 100644
--- a/tools/testing/selftests/vfio/lib/vfio_pci_device.c
+++ b/tools/testing/selftests/vfio/lib/vfio_pci_device.c
@@ -25,8 +25,6 @@
 #include "kselftest.h"
 #include <libvfio.h>
 
-#define PCI_SYSFS_PATH	"/sys/bus/pci/devices"
-
 static void vfio_pci_irq_set(struct vfio_pci_device *device,
 			     u32 index, u32 vector, u32 count, int *fds)
 {
@@ -202,24 +200,6 @@ void vfio_pci_device_reset(struct vfio_pci_device *device)
 	ioctl_assert(device->fd, VFIO_DEVICE_RESET, NULL);
 }
 
-static unsigned int vfio_pci_get_group_from_dev(const char *bdf)
-{
-	char dev_iommu_group_path[PATH_MAX] = {0};
-	char sysfs_path[PATH_MAX] = {0};
-	unsigned int group;
-	int ret;
-
-	snprintf_assert(sysfs_path, PATH_MAX, "%s/%s/iommu_group", PCI_SYSFS_PATH, bdf);
-
-	ret = readlink(sysfs_path, dev_iommu_group_path, sizeof(dev_iommu_group_path));
-	VFIO_ASSERT_NE(ret, -1, "Failed to get the IOMMU group for device: %s\n", bdf);
-
-	ret = sscanf(basename(dev_iommu_group_path), "%u", &group);
-	VFIO_ASSERT_EQ(ret, 1, "Failed to get the IOMMU group for device: %s\n", bdf);
-
-	return group;
-}
-
 static void vfio_pci_group_setup(struct vfio_pci_device *device, const char *bdf)
 {
 	struct vfio_group_status group_status = {
@@ -228,7 +208,7 @@ static void vfio_pci_group_setup(struct vfio_pci_device *device, const char *bdf
 	char group_path[32];
 	int group;
 
-	group = vfio_pci_get_group_from_dev(bdf);
+	group = sysfs_iommu_group_get(bdf);
 	snprintf_assert(group_path, sizeof(group_path), "/dev/vfio/%d", group);
 
 	device->group_fd = open(group_path, O_RDWR);
-- 
2.53.0.473.g4a7958ca14-goog

[PATCH v6 4/8] vfio: selftests: Extend container/iommufd setup for passing vf_token

[Raghavendra Rao Ananta]

A UUID is normally set as a vf_token to correspond the VFs with the
PFs, if they are both bound by the vfio-pci driver. This is true for
iommufd-based approach and container-based approach. The token can be
set either during device creation (VFIO_GROUP_GET_DEVICE_FD) in
container-based approach or during iommu bind (VFIO_DEVICE_BIND_IOMMUFD)
in the iommu-fd case. Hence extend the functions,
vfio_pci_iommufd_setup() and vfio_pci_container_setup(), to accept
vf_token as an (optional) argument and handle the necessary setup.

No functional changes are expected.

Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
Reviewed-by: David Matlack <dmatlack@google.com>
---
 tools/testing/selftests/vfio/Makefile         |  2 +
 .../selftests/vfio/lib/vfio_pci_device.c      | 46 +++++++++++++++----
 2 files changed, 40 insertions(+), 8 deletions(-)

diff --git a/tools/testing/selftests/vfio/Makefile b/tools/testing/selftests/vfio/Makefile
index 6a9ac6dd32cb6..f27ed18070f14 100644
--- a/tools/testing/selftests/vfio/Makefile
+++ b/tools/testing/selftests/vfio/Makefile
@@ -28,6 +28,8 @@ CFLAGS += $(EXTRA_CFLAGS)
 
 LDFLAGS += -pthread
 
+LDLIBS += -luuid
+
 $(TEST_GEN_PROGS): %: %.o $(LIBVFIO_O)
 	$(CC) $(CFLAGS) $(CPPFLAGS) $(LDFLAGS) $< $(LIBVFIO_O) $(LDLIBS) -o $@
 
diff --git a/tools/testing/selftests/vfio/lib/vfio_pci_device.c b/tools/testing/selftests/vfio/lib/vfio_pci_device.c
index 82f255f0486dc..dc8b37df8d1f1 100644
--- a/tools/testing/selftests/vfio/lib/vfio_pci_device.c
+++ b/tools/testing/selftests/vfio/lib/vfio_pci_device.c
@@ -22,6 +22,8 @@
 #include <linux/types.h>
 #include <linux/vfio.h>
 
+#include <uuid/uuid.h>
+
 #include "kselftest.h"
 #include <libvfio.h>
 
@@ -220,7 +222,27 @@ static void vfio_pci_group_setup(struct vfio_pci_device *device, const char *bdf
 	ioctl_assert(device->group_fd, VFIO_GROUP_SET_CONTAINER, &device->iommu->container_fd);
 }
 
-static void vfio_pci_container_setup(struct vfio_pci_device *device, const char *bdf)
+static void vfio_pci_group_get_device_fd(struct vfio_pci_device *device,
+					 const char *bdf, const char *vf_token)
+{
+	char arg[64];
+
+	/*
+	 * If a vf_token exists, argument to VFIO_GROUP_GET_DEVICE_FD
+	 * will be in the form of the following example:
+	 * "0000:04:10.0 vf_token=bd8d9d2b-5a5f-4f5a-a211-f591514ba1f3"
+	 */
+	if (vf_token)
+		snprintf_assert(arg, ARRAY_SIZE(arg), "%s vf_token=%s", bdf, vf_token);
+	else
+		snprintf_assert(arg, ARRAY_SIZE(arg), "%s", bdf);
+
+	device->fd = ioctl(device->group_fd, VFIO_GROUP_GET_DEVICE_FD, arg);
+	VFIO_ASSERT_GE(device->fd, 0);
+}
+
+static void vfio_pci_container_setup(struct vfio_pci_device *device,
+				     const char *bdf, const char *vf_token)
 {
 	struct iommu *iommu = device->iommu;
 	unsigned long iommu_type = iommu->mode->iommu_type;
@@ -238,8 +260,7 @@ static void vfio_pci_container_setup(struct vfio_pci_device *device, const char
 	 */
 	(void)ioctl(iommu->container_fd, VFIO_SET_IOMMU, (void *)iommu_type);
 
-	device->fd = ioctl(device->group_fd, VFIO_GROUP_GET_DEVICE_FD, bdf);
-	VFIO_ASSERT_GE(device->fd, 0);
+	vfio_pci_group_get_device_fd(device, bdf, vf_token);
 }
 
 static void vfio_pci_device_setup(struct vfio_pci_device *device)
@@ -300,12 +321,20 @@ const char *vfio_pci_get_cdev_path(const char *bdf)
 	return cdev_path;
 }
 
-static void vfio_device_bind_iommufd(int device_fd, int iommufd)
+static void vfio_device_bind_iommufd(int device_fd, int iommufd,
+				     const char *vf_token)
 {
 	struct vfio_device_bind_iommufd args = {
 		.argsz = sizeof(args),
 		.iommufd = iommufd,
 	};
+	uuid_t token_uuid;
+
+	if (vf_token) {
+		VFIO_ASSERT_EQ(uuid_parse(vf_token, token_uuid), 0);
+		args.flags |= VFIO_DEVICE_BIND_FLAG_TOKEN;
+		args.token_uuid_ptr = (u64)token_uuid;
+	}
 
 	ioctl_assert(device_fd, VFIO_DEVICE_BIND_IOMMUFD, &args);
 }
@@ -320,7 +349,8 @@ static void vfio_device_attach_iommufd_pt(int device_fd, u32 pt_id)
 	ioctl_assert(device_fd, VFIO_DEVICE_ATTACH_IOMMUFD_PT, &args);
 }
 
-static void vfio_pci_iommufd_setup(struct vfio_pci_device *device, const char *bdf)
+static void vfio_pci_iommufd_setup(struct vfio_pci_device *device,
+				   const char *bdf, const char *vf_token)
 {
 	const char *cdev_path = vfio_pci_get_cdev_path(bdf);
 
@@ -328,7 +358,7 @@ static void vfio_pci_iommufd_setup(struct vfio_pci_device *device, const char *b
 	VFIO_ASSERT_GE(device->fd, 0);
 	free((void *)cdev_path);
 
-	vfio_device_bind_iommufd(device->fd, device->iommu->iommufd);
+	vfio_device_bind_iommufd(device->fd, device->iommu->iommufd, vf_token);
 	vfio_device_attach_iommufd_pt(device->fd, device->iommu->ioas_id);
 }
 
@@ -344,9 +374,9 @@ struct vfio_pci_device *vfio_pci_device_init(const char *bdf, struct iommu *iomm
 	device->bdf = bdf;
 
 	if (iommu->mode->container_path)
-		vfio_pci_container_setup(device, bdf);
+		vfio_pci_container_setup(device, bdf, NULL);
 	else
-		vfio_pci_iommufd_setup(device, bdf);
+		vfio_pci_iommufd_setup(device, bdf, NULL);
 
 	vfio_pci_device_setup(device);
 	vfio_pci_driver_probe(device);
-- 
2.53.0.473.g4a7958ca14-goog

[PATCH v6 5/8] vfio: selftests: Expose more vfio_pci_device functions

[Raghavendra Rao Ananta]

Refactor and make the functions called under device initialization
public. A later patch adds a test that calls these functions to validate
the UAPI of SR-IOV devices. Opportunistically, to test the success
and failure cases of the UAPI, split the functions dealing with
VFIO_GROUP_GET_DEVICE_FD and VFIO_DEVICE_BIND_IOMMUFD into a core
function and another one that asserts the ioctl. The former will be
used for testing the SR-IOV UAPI, hence only export these.

Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
Reviewed-by: David Matlack <dmatlack@google.com>
---
 .../lib/include/libvfio/vfio_pci_device.h     |  7 +++
 .../selftests/vfio/lib/vfio_pci_device.c      | 47 ++++++++++++++-----
 2 files changed, 42 insertions(+), 12 deletions(-)

diff --git a/tools/testing/selftests/vfio/lib/include/libvfio/vfio_pci_device.h b/tools/testing/selftests/vfio/lib/include/libvfio/vfio_pci_device.h
index 2858885a89bbb..898de032fed5a 100644
--- a/tools/testing/selftests/vfio/lib/include/libvfio/vfio_pci_device.h
+++ b/tools/testing/selftests/vfio/lib/include/libvfio/vfio_pci_device.h
@@ -122,4 +122,11 @@ static inline bool vfio_pci_device_match(struct vfio_pci_device *device,
 
 const char *vfio_pci_get_cdev_path(const char *bdf);
 
+void vfio_pci_group_setup(struct vfio_pci_device *device, const char *bdf);
+void __vfio_pci_group_get_device_fd(struct vfio_pci_device *device,
+				    const char *bdf, const char *vf_token);
+void vfio_container_set_iommu(struct vfio_pci_device *device);
+void vfio_pci_cdev_open(struct vfio_pci_device *device, const char *bdf);
+int __vfio_device_bind_iommufd(int device_fd, int iommufd, const char *vf_token);
+
 #endif /* SELFTESTS_VFIO_LIB_INCLUDE_LIBVFIO_VFIO_PCI_DEVICE_H */
diff --git a/tools/testing/selftests/vfio/lib/vfio_pci_device.c b/tools/testing/selftests/vfio/lib/vfio_pci_device.c
index dc8b37df8d1f1..3123ba591f088 100644
--- a/tools/testing/selftests/vfio/lib/vfio_pci_device.c
+++ b/tools/testing/selftests/vfio/lib/vfio_pci_device.c
@@ -202,7 +202,7 @@ void vfio_pci_device_reset(struct vfio_pci_device *device)
 	ioctl_assert(device->fd, VFIO_DEVICE_RESET, NULL);
 }
 
-static void vfio_pci_group_setup(struct vfio_pci_device *device, const char *bdf)
+void vfio_pci_group_setup(struct vfio_pci_device *device, const char *bdf)
 {
 	struct vfio_group_status group_status = {
 		.argsz = sizeof(group_status),
@@ -222,8 +222,8 @@ static void vfio_pci_group_setup(struct vfio_pci_device *device, const char *bdf
 	ioctl_assert(device->group_fd, VFIO_GROUP_SET_CONTAINER, &device->iommu->container_fd);
 }
 
-static void vfio_pci_group_get_device_fd(struct vfio_pci_device *device,
-					 const char *bdf, const char *vf_token)
+void __vfio_pci_group_get_device_fd(struct vfio_pci_device *device,
+				    const char *bdf, const char *vf_token)
 {
 	char arg[64];
 
@@ -238,18 +238,21 @@ static void vfio_pci_group_get_device_fd(struct vfio_pci_device *device,
 		snprintf_assert(arg, ARRAY_SIZE(arg), "%s", bdf);
 
 	device->fd = ioctl(device->group_fd, VFIO_GROUP_GET_DEVICE_FD, arg);
+}
+
+static void vfio_pci_group_get_device_fd(struct vfio_pci_device *device,
+					 const char *bdf, const char *vf_token)
+{
+	__vfio_pci_group_get_device_fd(device, bdf, vf_token);
 	VFIO_ASSERT_GE(device->fd, 0);
 }
 
-static void vfio_pci_container_setup(struct vfio_pci_device *device,
-				     const char *bdf, const char *vf_token)
+void vfio_container_set_iommu(struct vfio_pci_device *device)
 {
 	struct iommu *iommu = device->iommu;
 	unsigned long iommu_type = iommu->mode->iommu_type;
 	int ret;
 
-	vfio_pci_group_setup(device, bdf);
-
 	ret = ioctl(iommu->container_fd, VFIO_CHECK_EXTENSION, iommu_type);
 	VFIO_ASSERT_GT(ret, 0, "VFIO IOMMU type %lu not supported\n", iommu_type);
 
@@ -259,7 +262,13 @@ static void vfio_pci_container_setup(struct vfio_pci_device *device,
 	 * because the IOMMU type is already set.
 	 */
 	(void)ioctl(iommu->container_fd, VFIO_SET_IOMMU, (void *)iommu_type);
+}
 
+static void vfio_pci_container_setup(struct vfio_pci_device *device,
+				     const char *bdf, const char *vf_token)
+{
+	vfio_pci_group_setup(device, bdf);
+	vfio_container_set_iommu(device);
 	vfio_pci_group_get_device_fd(device, bdf, vf_token);
 }
 
@@ -321,8 +330,7 @@ const char *vfio_pci_get_cdev_path(const char *bdf)
 	return cdev_path;
 }
 
-static void vfio_device_bind_iommufd(int device_fd, int iommufd,
-				     const char *vf_token)
+int __vfio_device_bind_iommufd(int device_fd, int iommufd, const char *vf_token)
 {
 	struct vfio_device_bind_iommufd args = {
 		.argsz = sizeof(args),
@@ -336,7 +344,18 @@ static void vfio_device_bind_iommufd(int device_fd, int iommufd,
 		args.token_uuid_ptr = (u64)token_uuid;
 	}
 
-	ioctl_assert(device_fd, VFIO_DEVICE_BIND_IOMMUFD, &args);
+	if (ioctl(device_fd, VFIO_DEVICE_BIND_IOMMUFD, &args))
+		return -errno;
+
+	return 0;
+}
+
+static void vfio_device_bind_iommufd(int device_fd, int iommufd,
+				     const char *vf_token)
+{
+	int ret = __vfio_device_bind_iommufd(device_fd, iommufd, vf_token);
+
+	VFIO_ASSERT_EQ(ret, 0, "Failed VFIO_DEVICE_BIND_IOMMUFD ioctl\n");
 }
 
 static void vfio_device_attach_iommufd_pt(int device_fd, u32 pt_id)
@@ -349,15 +368,19 @@ static void vfio_device_attach_iommufd_pt(int device_fd, u32 pt_id)
 	ioctl_assert(device_fd, VFIO_DEVICE_ATTACH_IOMMUFD_PT, &args);
 }
 
-static void vfio_pci_iommufd_setup(struct vfio_pci_device *device,
-				   const char *bdf, const char *vf_token)
+void vfio_pci_cdev_open(struct vfio_pci_device *device, const char *bdf)
 {
 	const char *cdev_path = vfio_pci_get_cdev_path(bdf);
 
 	device->fd = open(cdev_path, O_RDWR);
 	VFIO_ASSERT_GE(device->fd, 0);
 	free((void *)cdev_path);
+}
 
+static void vfio_pci_iommufd_setup(struct vfio_pci_device *device,
+				   const char *bdf, const char *vf_token)
+{
+	vfio_pci_cdev_open(device, bdf);
 	vfio_device_bind_iommufd(device->fd, device->iommu->iommufd, vf_token);
 	vfio_device_attach_iommufd_pt(device->fd, device->iommu->ioas_id);
 }
-- 
2.53.0.473.g4a7958ca14-goog

[PATCH v6 6/8] vfio: selftests: Add helper to set/override a vf_token

[Raghavendra Rao Ananta]

Add a helper function, vfio_device_set_vf_token(), to set or override a
vf_token. Not only at init, but a vf_token can also be set via the
VFIO_DEVICE_FEATURE ioctl, by setting the
VFIO_DEVICE_FEATURE_PCI_VF_TOKEN flag. Hence, add an API to utilize this
functionality from the test code. The subsequent commit will use this to
test the functionality of this method to set the vf_token.

Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
Reviewed-by: David Matlack <dmatlack@google.com>
---
 .../lib/include/libvfio/vfio_pci_device.h     |  2 ++
 .../selftests/vfio/lib/vfio_pci_device.c      | 34 +++++++++++++++++++
 2 files changed, 36 insertions(+)

diff --git a/tools/testing/selftests/vfio/lib/include/libvfio/vfio_pci_device.h b/tools/testing/selftests/vfio/lib/include/libvfio/vfio_pci_device.h
index 898de032fed5a..4ebdc00e20fca 100644
--- a/tools/testing/selftests/vfio/lib/include/libvfio/vfio_pci_device.h
+++ b/tools/testing/selftests/vfio/lib/include/libvfio/vfio_pci_device.h
@@ -129,4 +129,6 @@ void vfio_container_set_iommu(struct vfio_pci_device *device);
 void vfio_pci_cdev_open(struct vfio_pci_device *device, const char *bdf);
 int __vfio_device_bind_iommufd(int device_fd, int iommufd, const char *vf_token);
 
+void vfio_device_set_vf_token(int fd, const char *vf_token);
+
 #endif /* SELFTESTS_VFIO_LIB_INCLUDE_LIBVFIO_VFIO_PCI_DEVICE_H */
diff --git a/tools/testing/selftests/vfio/lib/vfio_pci_device.c b/tools/testing/selftests/vfio/lib/vfio_pci_device.c
index 3123ba591f088..4673b148f8c44 100644
--- a/tools/testing/selftests/vfio/lib/vfio_pci_device.c
+++ b/tools/testing/selftests/vfio/lib/vfio_pci_device.c
@@ -113,6 +113,40 @@ static void vfio_pci_irq_get(struct vfio_pci_device *device, u32 index,
 	ioctl_assert(device->fd, VFIO_DEVICE_GET_IRQ_INFO, irq_info);
 }
 
+static int vfio_device_feature_ioctl(int fd, u32 flags, void *data,
+				     size_t data_size)
+{
+	u8 buffer[sizeof(struct vfio_device_feature) + data_size] = {};
+	struct vfio_device_feature *feature = (void *)buffer;
+
+	memcpy(feature->data, data, data_size);
+
+	feature->argsz = sizeof(buffer);
+	feature->flags = flags;
+
+	return ioctl(fd, VFIO_DEVICE_FEATURE, feature);
+}
+
+static void vfio_device_feature_set(int fd, u16 feature, void *data, size_t data_size)
+{
+	u32 flags = VFIO_DEVICE_FEATURE_SET | feature;
+	int ret;
+
+	ret = vfio_device_feature_ioctl(fd, flags, data, data_size);
+	VFIO_ASSERT_EQ(ret, 0, "Failed to set feature %u\n", feature);
+}
+
+void vfio_device_set_vf_token(int fd, const char *vf_token)
+{
+	uuid_t token_uuid = {0};
+
+	VFIO_ASSERT_NOT_NULL(vf_token, "vf_token is NULL");
+	VFIO_ASSERT_EQ(uuid_parse(vf_token, token_uuid), 0);
+
+	vfio_device_feature_set(fd, VFIO_DEVICE_FEATURE_PCI_VF_TOKEN,
+				token_uuid, sizeof(uuid_t));
+}
+
 static void vfio_pci_region_get(struct vfio_pci_device *device, int index,
 				struct vfio_region_info *info)
 {
-- 
2.53.0.473.g4a7958ca14-goog

[PATCH v6 7/8] vfio: selftests: Add helpers to alloc/free vfio_pci_device

[Raghavendra Rao Ananta]

Add a helper, vfio_pci_device_alloc(), to allocate 'struct
vfio_pci_device'. The subsequent test patch will utilize this
to get the struct with very minimal initialization done.
Internally, let vfio_pci_device_init() also make use of this
function and later do the full initialization.

Symmetrically, add a free variant, vfio_pci_device_free(),
to be used in a similar fashion.

No functional change intended.

Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
Reviewed-by: David Matlack <dmatlack@google.com>
---
 .../vfio/lib/include/libvfio/vfio_pci_device.h |  2 ++
 .../selftests/vfio/lib/vfio_pci_device.c       | 18 ++++++++++++++++--
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/vfio/lib/include/libvfio/vfio_pci_device.h b/tools/testing/selftests/vfio/lib/include/libvfio/vfio_pci_device.h
index 4ebdc00e20fca..3eabead717bbd 100644
--- a/tools/testing/selftests/vfio/lib/include/libvfio/vfio_pci_device.h
+++ b/tools/testing/selftests/vfio/lib/include/libvfio/vfio_pci_device.h
@@ -38,6 +38,8 @@ struct vfio_pci_device {
 #define dev_info(_dev, _fmt, ...) printf("%s: " _fmt, (_dev)->bdf, ##__VA_ARGS__)
 #define dev_err(_dev, _fmt, ...) fprintf(stderr, "%s: " _fmt, (_dev)->bdf, ##__VA_ARGS__)
 
+struct vfio_pci_device *vfio_pci_device_alloc(const char *bdf, struct iommu *iommu);
+void vfio_pci_device_free(struct vfio_pci_device *device);
 struct vfio_pci_device *vfio_pci_device_init(const char *bdf, struct iommu *iommu);
 void vfio_pci_device_cleanup(struct vfio_pci_device *device);
 
diff --git a/tools/testing/selftests/vfio/lib/vfio_pci_device.c b/tools/testing/selftests/vfio/lib/vfio_pci_device.c
index 4673b148f8c44..4ff76970e3791 100644
--- a/tools/testing/selftests/vfio/lib/vfio_pci_device.c
+++ b/tools/testing/selftests/vfio/lib/vfio_pci_device.c
@@ -419,7 +419,7 @@ static void vfio_pci_iommufd_setup(struct vfio_pci_device *device,
 	vfio_device_attach_iommufd_pt(device->fd, device->iommu->ioas_id);
 }
 
-struct vfio_pci_device *vfio_pci_device_init(const char *bdf, struct iommu *iommu)
+struct vfio_pci_device *vfio_pci_device_alloc(const char *bdf, struct iommu *iommu)
 {
 	struct vfio_pci_device *device;
 
@@ -430,6 +430,20 @@ struct vfio_pci_device *vfio_pci_device_init(const char *bdf, struct iommu *iomm
 	device->iommu = iommu;
 	device->bdf = bdf;
 
+	return device;
+}
+
+void vfio_pci_device_free(struct vfio_pci_device *device)
+{
+	free(device);
+}
+
+struct vfio_pci_device *vfio_pci_device_init(const char *bdf, struct iommu *iommu)
+{
+	struct vfio_pci_device *device;
+
+	device = vfio_pci_device_alloc(bdf, iommu);
+
 	if (iommu->mode->container_path)
 		vfio_pci_container_setup(device, bdf, NULL);
 	else
@@ -462,5 +476,5 @@ void vfio_pci_device_cleanup(struct vfio_pci_device *device)
 	if (device->group_fd)
 		VFIO_ASSERT_EQ(close(device->group_fd), 0);
 
-	free(device);
+	vfio_pci_device_free(device);
 }
-- 
2.53.0.473.g4a7958ca14-goog

[PATCH v6 8/8] vfio: selftests: Add tests to validate SR-IOV UAPI

[Raghavendra Rao Ananta]

Add a selftest, vfio_pci_sriov_uapi_test.c, to validate the
SR-IOV UAPI, including the following cases, iterating over
all the IOMMU modes currently supported:
 - Setting correct/incorrect/NULL tokens during device init.
 - Close the PF device immediately after setting the token.
 - Change/override the PF's token after device init.

Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
Reviewed-by: David Matlack <dmatlack@google.com>
---
 tools/testing/selftests/vfio/Makefile         |   1 +
 .../selftests/vfio/vfio_pci_sriov_uapi_test.c | 200 ++++++++++++++++++
 2 files changed, 201 insertions(+)
 create mode 100644 tools/testing/selftests/vfio/vfio_pci_sriov_uapi_test.c

diff --git a/tools/testing/selftests/vfio/Makefile b/tools/testing/selftests/vfio/Makefile
index f27ed18070f14..d0c8cea53eb54 100644
--- a/tools/testing/selftests/vfio/Makefile
+++ b/tools/testing/selftests/vfio/Makefile
@@ -12,6 +12,7 @@ TEST_GEN_PROGS += vfio_iommufd_setup_test
 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_FILES += scripts/cleanup.sh
 TEST_FILES += scripts/lib.sh
diff --git a/tools/testing/selftests/vfio/vfio_pci_sriov_uapi_test.c b/tools/testing/selftests/vfio/vfio_pci_sriov_uapi_test.c
new file mode 100644
index 0000000000000..9cfbecccb759f
--- /dev/null
+++ b/tools/testing/selftests/vfio/vfio_pci_sriov_uapi_test.c
@@ -0,0 +1,200 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <sys/ioctl.h>
+#include <linux/limits.h>
+
+#include <libvfio.h>
+
+#include "../kselftest_harness.h"
+
+#define UUID_1 "52ac9bff-3a88-4fbd-901a-0d767c3b6c97"
+#define UUID_2 "88594674-90a0-47a9-aea8-9d9b352ac08a"
+
+static const char *pf_bdf;
+
+static int container_setup(struct vfio_pci_device *device, const char *bdf,
+			   const char *vf_token)
+{
+	vfio_pci_group_setup(device, bdf);
+	vfio_container_set_iommu(device);
+	__vfio_pci_group_get_device_fd(device, bdf, vf_token);
+
+	/* The device fd will be -1 in case of mismatched tokens */
+	return (device->fd < 0);
+}
+
+static int iommufd_setup(struct vfio_pci_device *device, const char *bdf,
+			 const char *vf_token)
+{
+	vfio_pci_cdev_open(device, bdf);
+	return __vfio_device_bind_iommufd(device->fd,
+					  device->iommu->iommufd, vf_token);
+}
+
+static struct vfio_pci_device *device_init(const char *bdf, struct iommu *iommu,
+					   const char *vf_token, int *out_ret)
+{
+	struct vfio_pci_device *device = vfio_pci_device_alloc(bdf, iommu);
+
+	if (iommu->mode->container_path)
+		*out_ret = container_setup(device, bdf, vf_token);
+	else
+		*out_ret = iommufd_setup(device, bdf, vf_token);
+
+	return device;
+}
+
+static void device_cleanup(struct vfio_pci_device *device)
+{
+	if (device->fd > 0)
+		VFIO_ASSERT_EQ(close(device->fd), 0);
+
+	if (device->group_fd)
+		VFIO_ASSERT_EQ(close(device->group_fd), 0);
+
+	vfio_pci_device_free(device);
+}
+
+FIXTURE(vfio_pci_sriov_uapi_test) {
+	char *vf_bdf;
+};
+
+FIXTURE_SETUP(vfio_pci_sriov_uapi_test)
+{
+	char *vf_driver;
+	int nr_vfs;
+
+	nr_vfs = sysfs_sriov_totalvfs_get(pf_bdf);
+	if (nr_vfs <= 0)
+		SKIP(return, "SR-IOV may not be supported by the PF: %s\n", pf_bdf);
+
+	nr_vfs = sysfs_sriov_numvfs_get(pf_bdf);
+	if (nr_vfs != 0)
+		SKIP(return, "SR-IOV already configured for the PF: %s\n", pf_bdf);
+
+	/* Create only one VF for testing */
+	sysfs_sriov_numvfs_set(pf_bdf, 1);
+	self->vf_bdf = sysfs_sriov_vf_bdf_get(pf_bdf, 0);
+
+	/*
+	 * The VF inherits the driver from the PF.
+	 * Ensure this is 'vfio-pci' before proceeding.
+	 */
+	vf_driver = sysfs_driver_get(self->vf_bdf);
+	ASSERT_NE(vf_driver, NULL);
+	ASSERT_EQ(strcmp(vf_driver, "vfio-pci"), 0);
+	free(vf_driver);
+
+	printf("Created 1 VF (%s) under the PF: %s\n", self->vf_bdf, pf_bdf);
+}
+
+FIXTURE_TEARDOWN(vfio_pci_sriov_uapi_test)
+{
+	free(self->vf_bdf);
+	sysfs_sriov_numvfs_set(pf_bdf, 0);
+}
+
+FIXTURE_VARIANT(vfio_pci_sriov_uapi_test) {
+	const char *iommu_mode;
+	char *vf_token;
+};
+
+#define FIXTURE_VARIANT_ADD_IOMMU_MODE(_iommu_mode, _name, _vf_token)		\
+FIXTURE_VARIANT_ADD(vfio_pci_sriov_uapi_test, _iommu_mode ## _ ## _name) {	\
+	.iommu_mode = #_iommu_mode,						\
+	.vf_token = (_vf_token),						\
+}
+
+FIXTURE_VARIANT_ADD_ALL_IOMMU_MODES(same_uuid, UUID_1);
+FIXTURE_VARIANT_ADD_ALL_IOMMU_MODES(diff_uuid, UUID_2);
+FIXTURE_VARIANT_ADD_ALL_IOMMU_MODES(null_uuid, NULL);
+
+/*
+ * PF's token is always set with UUID_1 and VF's token is rotated with
+ * various tokens (including UUID_1 and NULL).
+ * This asserts if the VF device is successfully created for a match
+ * in the token or actually fails during a mismatch.
+ */
+#define ASSERT_VF_CREATION(_ret) do {					\
+	if (!variant->vf_token || strcmp(UUID_1, variant->vf_token)) {	\
+		ASSERT_NE((_ret), 0);					\
+	} else {							\
+		ASSERT_EQ((_ret), 0);					\
+	}								\
+} while (0)
+
+/*
+ * Validate if the UAPI handles correctly and incorrectly set token on the VF.
+ */
+TEST_F(vfio_pci_sriov_uapi_test, init_token_match)
+{
+	struct vfio_pci_device *pf;
+	struct vfio_pci_device *vf;
+	struct iommu *iommu;
+	int ret;
+
+	iommu = iommu_init(variant->iommu_mode);
+	pf = device_init(pf_bdf, iommu, UUID_1, &ret);
+	vf = device_init(self->vf_bdf, iommu, variant->vf_token, &ret);
+
+	ASSERT_VF_CREATION(ret);
+
+	device_cleanup(vf);
+	device_cleanup(pf);
+	iommu_cleanup(iommu);
+}
+
+/*
+ * After setting a token on the PF, validate if the VF can still set the
+ * expected token.
+ */
+TEST_F(vfio_pci_sriov_uapi_test, pf_early_close)
+{
+	struct vfio_pci_device *pf;
+	struct vfio_pci_device *vf;
+	struct iommu *iommu;
+	int ret;
+
+	iommu = iommu_init(variant->iommu_mode);
+	pf = device_init(pf_bdf, iommu, UUID_1, &ret);
+	device_cleanup(pf);
+
+	vf = device_init(self->vf_bdf, iommu, variant->vf_token, &ret);
+
+	ASSERT_VF_CREATION(ret);
+
+	device_cleanup(vf);
+	iommu_cleanup(iommu);
+}
+
+/*
+ * After PF device init, override the existing token and validate if the newly
+ * set token is the one that's active.
+ */
+TEST_F(vfio_pci_sriov_uapi_test, override_token)
+{
+	struct vfio_pci_device *pf;
+	struct vfio_pci_device *vf;
+	struct iommu *iommu;
+	int ret;
+
+	iommu = iommu_init(variant->iommu_mode);
+	pf = device_init(pf_bdf, iommu, UUID_2, &ret);
+	vfio_device_set_vf_token(pf->fd, UUID_1);
+
+	vf = device_init(self->vf_bdf, iommu, variant->vf_token, &ret);
+
+	ASSERT_VF_CREATION(ret);
+
+	device_cleanup(vf);
+	device_cleanup(pf);
+	iommu_cleanup(iommu);
+}
+
+int main(int argc, char *argv[])
+{
+	pf_bdf = vfio_selftests_get_bdf(&argc, argv);
+	return test_harness_run(argc, argv);
+}
-- 
2.53.0.473.g4a7958ca14-goog

Re: [PATCH v6 3/8] vfio: selftests: Introduce a sysfs lib

[David Matlack]

On 2026-03-03 07:38 PM, Raghavendra Rao Ananta wrote:

> +	ret = readlink(path, vf_path, PATH_MAX);
> +	VFIO_ASSERT_NE(ret, -1);
> +	vf_path[ret] = '\0';

...

> +	ret = readlink(path, dev_iommu_group_path, sizeof(dev_iommu_group_path));
> +	VFIO_ASSERT_NE(ret, -1, "Failed to get the IOMMU group for device: %s\n", bdf);
> +	dev_iommu_group_path[ret] = '\0';

...

> +	ret = readlink(path, driver_path, PATH_MAX);
> +	if (ret == -1) {
> +		free(out_driver);
> +
> +		if (errno == ENOENT)
> +			return NULL;
> +
> +		VFIO_FAIL("Failed to read %s\n", path);
> +	}
> +	driver_path[ret] = '\0';

These can all write off the end of the buffer if ret == PATH_MAX.

Also there is an inconsistency in these calls. 2 use hard-coded PATH_MAX
while the other uses sizeof().

Perhaps add a wrapper to handle all the details?

#define readlink_safe(path, buf) ({                           \
	int __ret = readlink(_path, _buf, sizeof(_buf) - 1);  \
	if (__ret != -1)                                      \
		_buf[__ret] = 0;                              \
	__ret;
})

Re: [PATCH v6 3/8] vfio: selftests: Introduce a sysfs lib

[Vipin Sharma]

On 2026-03-03 19:38:17, Raghavendra Rao Ananta wrote:
> +char *sysfs_sriov_vf_bdf_get(const char *pf_bdf, int i)
> +{
> +	char vf_path[PATH_MAX];
> +	char path[PATH_MAX];
> +	char *out_vf_bdf;
> +	int ret;
> +
> +	out_vf_bdf = calloc(16, sizeof(char));

A comment of /* ../0000:00:00.0 */ would be nice to tell why 16 is
chosen.

> +	VFIO_ASSERT_NOT_NULL(out_vf_bdf);
> +
> +	snprintf_assert(path, PATH_MAX, "/sys/bus/pci/devices/%s/virtfn%d", pf_bdf, i);
> +
> +	ret = readlink(path, vf_path, PATH_MAX);
> +	VFIO_ASSERT_NE(ret, -1);
> +	vf_path[ret] = '\0';

Can we just initialize vf_path to {0} at the beginning and not worry
here?

> +
> +	ret = sscanf(basename(vf_path), "%s", out_vf_bdf);
> +	VFIO_ASSERT_EQ(ret, 1);
> +
> +	return out_vf_bdf;
> +}
> +
> +unsigned int sysfs_iommu_group_get(const char *bdf)
> +{
> +	char dev_iommu_group_path[PATH_MAX];
> +	char path[PATH_MAX];
> +	unsigned int group;

Why unsigned int? In kernel iommu_group id is int itself. Caller of this
function also casting it to int.

> +	int ret;
> +
> +	snprintf_assert(path, PATH_MAX, "/sys/bus/pci/devices/%s/iommu_group", bdf);
> +
> +	ret = readlink(path, dev_iommu_group_path, sizeof(dev_iommu_group_path));
> +	VFIO_ASSERT_NE(ret, -1, "Failed to get the IOMMU group for device: %s\n", bdf);
> +	dev_iommu_group_path[ret] = '\0';

Same, initialize at beginning.

> +
> +	ret = sscanf(basename(dev_iommu_group_path), "%u", &group);

Can we combine these operations into a single function? Seems like vfio,
iommu_group and driver all use the same pattern.

> +	VFIO_ASSERT_EQ(ret, 1, "Failed to get the IOMMU group for device: %s\n", bdf);
> +
> +	return group;
> +}
> +
> +char *sysfs_driver_get(const char *bdf)
> +{
> +	char driver_path[PATH_MAX];
> +	char path[PATH_MAX];
> +	char *out_driver;
> +	int ret;
> +
> +	out_driver = calloc(64, sizeof(char));

Comment on why 64?

> +	VFIO_ASSERT_NOT_NULL(out_driver);
> +
> +	snprintf_assert(path, PATH_MAX, "/sys/bus/pci/devices/%s/driver", bdf);
> +	ret = readlink(path, driver_path, PATH_MAX);
> +	if (ret == -1) {
> +		free(out_driver);
> +
> +		if (errno == ENOENT)
> +			return NULL;
> +
> +		VFIO_FAIL("Failed to read %s\n", path);
> +	}
> +	driver_path[ret] = '\0';

Same, initialize at beginning.

> +
> +	strcpy(out_driver, basename(driver_path));

They both have different lengths. Should we use strncpy()?

> +	return out_driver;

Re: [PATCH v6 8/8] vfio: selftests: Add tests to validate SR-IOV UAPI

[Vipin Sharma]

On 2026-03-03 19:38:22, Raghavendra Rao Ananta wrote:
> +static int container_setup(struct vfio_pci_device *device, const char *bdf,
> +			   const char *vf_token)
> +{
> +	vfio_pci_group_setup(device, bdf);
> +	vfio_container_set_iommu(device);
> +	__vfio_pci_group_get_device_fd(device, bdf, vf_token);
> +
> +	/* The device fd will be -1 in case of mismatched tokens */
> +	return (device->fd < 0);
> +}
> +

This is one is exactly similar to vfio_pci_container_setup() except you
are calling __vfio_pci_group_get_device_fd() which doesn't do assertion.

Any reason to not create __vfio_pci_container_setup() in the library and
just write assertion in vfio_pci_container_setup()? 

> +static int iommufd_setup(struct vfio_pci_device *device, const char *bdf,
> +			 const char *vf_token)
> +{
> +	vfio_pci_cdev_open(device, bdf);
> +	return __vfio_device_bind_iommufd(device->fd,
> +					  device->iommu->iommufd, vf_token);
> +}

I see these are also similar to the code in library with some
differences. May be we can refactor library code and reuse it here.

One option can be to split vfio_pci_iommufd_setup() in two parts where
first part is what your are doing above and second part is attaching PT.

> +
> +static struct vfio_pci_device *device_init(const char *bdf, struct iommu *iommu,
> +					   const char *vf_token, int *out_ret)
> +{
> +	struct vfio_pci_device *device = vfio_pci_device_alloc(bdf, iommu);
> +
> +	if (iommu->mode->container_path)
> +		*out_ret = container_setup(device, bdf, vf_token);
> +	else
> +		*out_ret = iommufd_setup(device, bdf, vf_token);
> +
> +	return device;
> +}

Same for this one, vfio_pci_device_init() can be composed of two parts,
first one being alloc and container/iommufd setup and second device
setup and driver probe.

My reasoning for this is to avoid having separate code for these common
flows and avoid them diverging down the line.

> +
> +static void device_cleanup(struct vfio_pci_device *device)
> +{
> +	if (device->fd > 0)
> +		VFIO_ASSERT_EQ(close(device->fd), 0);
> +
> +	if (device->group_fd)
> +		VFIO_ASSERT_EQ(close(device->group_fd), 0);
> +
> +	vfio_pci_device_free(device);
> +}
> +
> +FIXTURE(vfio_pci_sriov_uapi_test) {
> +	char *vf_bdf;

Nit: Can we just use an array like char vf_bdf[16]? 
Just not sure why we need to do alloc and free for each run.

> +};
> +
> +FIXTURE_SETUP(vfio_pci_sriov_uapi_test)
> +{
> +	char *vf_driver;
> +	int nr_vfs;
> +
> +	nr_vfs = sysfs_sriov_totalvfs_get(pf_bdf);
> +	if (nr_vfs <= 0)
> +		SKIP(return, "SR-IOV may not be supported by the PF: %s\n", pf_bdf);
> +
> +	nr_vfs = sysfs_sriov_numvfs_get(pf_bdf);
> +	if (nr_vfs != 0)
> +		SKIP(return, "SR-IOV already configured for the PF: %s\n", pf_bdf);
> +

If there is a test failure (ASSERT) then fixture cleanup will not run
leaving SR-IOV enabled and all subsequent tests will skip. 

Since this test is specific to SR-IOV and user is intentionally passing
a device to test, I think we can just reset the VFs to 0 before
proceeding instead of skipping.

> +	/* Create only one VF for testing */
> +	sysfs_sriov_numvfs_set(pf_bdf, 1);
> +	self->vf_bdf = sysfs_sriov_vf_bdf_get(pf_bdf, 0);
> +
> +	/*
> +	 * The VF inherits the driver from the PF.
> +	 * Ensure this is 'vfio-pci' before proceeding.
> +	 */
> +	vf_driver = sysfs_driver_get(self->vf_bdf);
> +	ASSERT_NE(vf_driver, NULL);
> +	ASSERT_EQ(strcmp(vf_driver, "vfio-pci"), 0);
> +	free(vf_driver);
> +
> +	printf("Created 1 VF (%s) under the PF: %s\n", self->vf_bdf, pf_bdf);
> +}
> +
> +FIXTURE_TEARDOWN(vfio_pci_sriov_uapi_test)
> +{
> +	free(self->vf_bdf);
> +	sysfs_sriov_numvfs_set(pf_bdf, 0);
> +}
> +
> +FIXTURE_VARIANT(vfio_pci_sriov_uapi_test) {
> +	const char *iommu_mode;
> +	char *vf_token;
> +};
> +
> +#define FIXTURE_VARIANT_ADD_IOMMU_MODE(_iommu_mode, _name, _vf_token)		\
> +FIXTURE_VARIANT_ADD(vfio_pci_sriov_uapi_test, _iommu_mode ## _ ## _name) {	\
> +	.iommu_mode = #_iommu_mode,						\
> +	.vf_token = (_vf_token),						\
> +}
> +
> +FIXTURE_VARIANT_ADD_ALL_IOMMU_MODES(same_uuid, UUID_1);
> +FIXTURE_VARIANT_ADD_ALL_IOMMU_MODES(diff_uuid, UUID_2);
> +FIXTURE_VARIANT_ADD_ALL_IOMMU_MODES(null_uuid, NULL);
> +
> +/*
> + * PF's token is always set with UUID_1 and VF's token is rotated with
> + * various tokens (including UUID_1 and NULL).
> + * This asserts if the VF device is successfully created for a match
> + * in the token or actually fails during a mismatch.
> + */
> +#define ASSERT_VF_CREATION(_ret) do {					\
> +	if (!variant->vf_token || strcmp(UUID_1, variant->vf_token)) {	\
> +		ASSERT_NE((_ret), 0);					\
> +	} else {							\
> +		ASSERT_EQ((_ret), 0);					\
> +	}								\
> +} while (0)
> +
> +/*
> + * Validate if the UAPI handles correctly and incorrectly set token on the VF.
> + */
> +TEST_F(vfio_pci_sriov_uapi_test, init_token_match)
> +{
> +	struct vfio_pci_device *pf;
> +	struct vfio_pci_device *vf;
> +	struct iommu *iommu;
> +	int ret;
> +
> +	iommu = iommu_init(variant->iommu_mode);

Can this and cleanup go in fixture setup?

> +	pf = device_init(pf_bdf, iommu, UUID_1, &ret);

We should assert here as well and in other functions.

> +	vf = device_init(self->vf_bdf, iommu, variant->vf_token, &ret);
> +
> +	ASSERT_VF_CREATION(ret);
> +
> +	device_cleanup(vf);
> +	device_cleanup(pf);
> +	iommu_cleanup(iommu);
> +}
> +
> +/*
> + * After setting a token on the PF, validate if the VF can still set the
> + * expected token.
> + */
> +TEST_F(vfio_pci_sriov_uapi_test, pf_early_close)
> +{
> +	struct vfio_pci_device *pf;
> +	struct vfio_pci_device *vf;
> +	struct iommu *iommu;
> +	int ret;
> +
> +	iommu = iommu_init(variant->iommu_mode);
> +	pf = device_init(pf_bdf, iommu, UUID_1, &ret);
> +	device_cleanup(pf);
> +
> +	vf = device_init(self->vf_bdf, iommu, variant->vf_token, &ret);
> +
> +	ASSERT_VF_CREATION(ret);
> +
> +	device_cleanup(vf);
> +	iommu_cleanup(iommu);
> +}
> +
> +/*
> + * After PF device init, override the existing token and validate if the newly
> + * set token is the one that's active.
> + */
> +TEST_F(vfio_pci_sriov_uapi_test, override_token)
> +{
> +	struct vfio_pci_device *pf;
> +	struct vfio_pci_device *vf;
> +	struct iommu *iommu;
> +	int ret;
> +
> +	iommu = iommu_init(variant->iommu_mode);
> +	pf = device_init(pf_bdf, iommu, UUID_2, &ret);
> +	vfio_device_set_vf_token(pf->fd, UUID_1);
> +
> +	vf = device_init(self->vf_bdf, iommu, variant->vf_token, &ret);
> +
> +	ASSERT_VF_CREATION(ret);
> +
> +	device_cleanup(vf);
> +	device_cleanup(pf);
> +	iommu_cleanup(iommu);
> +}
> +
> +int main(int argc, char *argv[])
> +{
> +	pf_bdf = vfio_selftests_get_bdf(&argc, argv);
> +	return test_harness_run(argc, argv);
> +}
> -- 
> 2.53.0.473.g4a7958ca14-goog
>