vfio: selftests: Extend container/iommufd setup for passing vf_token

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>
Reviewed-by: Vipin Sharma <vipinsh@google.com>
Tested-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20260505212838.1698034-5-rananta@google.com
Signed-off-by: Alex Williamson <alex@shazbot.org>

tools/testing/selftests/vfio/Makefile

@@ -28,6 +28,8 @@ CFLAGS += $(EXTRA_CFLAGS)
 
 LDFLAGS += -pthread
 
+LDLIBS += -luuid
+
 $(TEST_GEN_PROGS): $(OUTPUT)/%: $(OUTPUT)/%.o $(LIBVFIO_O)
 	$(CC) $(CFLAGS) $(CPPFLAGS) $(LDFLAGS) $< $(LIBVFIO_O) $(LDLIBS) -o $@
 

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>
 
@@ -222,7 +224,27 @@ 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;
@@ -240,8 +262,7 @@ 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_pci_group_get_device_fd(device, bdf, vf_token);
-	VFIO_ASSERT_GE(device->fd, 0);
 }
 
 static void vfio_pci_device_setup(struct vfio_pci_device *device)
@@ -302,12 +323,20 @@ 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);
 }
@@ -322,7 +351,8 @@ 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);
 
@@ -330,7 +360,7 @@ 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);
 }
 
@@ -346,9 +376,9 @@ 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);