[PATCH 3/4] vfio: selftests: Add helper to set/override a vf_token

[Raghavendra Rao Ananta <rananta@google.com>]

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. Add an API to utilize this
functionality from the test code.

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

diff --git a/tools/testing/selftests/vfio/lib/include/vfio_util.h b/tools/testing/selftests/vfio/lib/include/vfio_util.h
index 2baf12a888e67..f0a12646456a9 100644
--- a/tools/testing/selftests/vfio/lib/include/vfio_util.h
+++ b/tools/testing/selftests/vfio/lib/include/vfio_util.h
@@ -307,4 +307,6 @@ void vfio_pci_iommufd_cdev_open(struct vfio_pci_device *device, const char *bdf)
 void vfio_pci_iommufd_iommudev_open(struct vfio_pci_device *device);
 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_VFIO_UTIL_H */
diff --git a/tools/testing/selftests/vfio/lib/vfio_pci_device.c b/tools/testing/selftests/vfio/lib/vfio_pci_device.c
index 7a1547e365870..c0fa4e27a96ef 100644
--- a/tools/testing/selftests/vfio/lib/vfio_pci_device.c
+++ b/tools/testing/selftests/vfio/lib/vfio_pci_device.c
@@ -144,6 +144,40 @@ 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_iommu_dma_map(struct vfio_pci_device *device,
 			       struct vfio_dma_region *region)
 {
-- 
2.51.2.997.g839fc31de9-goog