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* [PATCH] vfio/pci: Do vf_token checks for VFIO_DEVICE_BIND_IOMMUFD
@ 2025-06-24 18:34 Jason Gunthorpe
  2025-06-24 20:06 ` Alex Williamson
  2025-07-03  6:40 ` Tian, Kevin
  0 siblings, 2 replies; 6+ messages in thread
From: Jason Gunthorpe @ 2025-06-24 18:34 UTC (permalink / raw)
  To: Ankit Agrawal, Brett Creeley, Giovanni Cabiddu, Kevin Tian, kvm,
	Longfang Liu, qat-linux, virtualization, Xin Zeng, Yishai Hadas
  Cc: Alex Williamson, Matthew Rosato, Nicolin Chen, patches,
	Shameer Kolothum, Terrence Xu, Yanting Jiang, Yi Liu,
	Zhenzhong Duan

This was missed during the initial implementation. The VFIO PCI encodes
the vf_token inside the device name when opening the device from the group
FD, something like:

  "0000:04:10.0 vf_token=bd8d9d2b-5a5f-4f5a-a211-f591514ba1f3"

This is used to control access to a VF unless there is co-ordination with
the owner of the PF.

Since we no longer have a device name pass the token directly though
VFIO_DEVICE_BIND_IOMMUFD with an optional field indicated by
VFIO_DEVICE_BIND_TOKEN. Only users using a PCI SRIOV VF will need to
provide this. This is done in the usual backwards compatible way.

Fixes: 5fcc26969a16 ("vfio: Add VFIO_DEVICE_BIND_IOMMUFD")
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
 drivers/vfio/device_cdev.c                    | 38 +++++++++++++++++--
 .../vfio/pci/hisilicon/hisi_acc_vfio_pci.c    |  1 +
 drivers/vfio/pci/mlx5/main.c                  |  1 +
 drivers/vfio/pci/nvgrace-gpu/main.c           |  2 +
 drivers/vfio/pci/pds/vfio_dev.c               |  1 +
 drivers/vfio/pci/qat/main.c                   |  1 +
 drivers/vfio/pci/vfio_pci.c                   |  1 +
 drivers/vfio/pci/vfio_pci_core.c              | 22 +++++++----
 drivers/vfio/pci/virtio/main.c                |  3 ++
 include/linux/vfio.h                          |  1 +
 include/linux/vfio_pci_core.h                 |  2 +
 include/uapi/linux/vfio.h                     | 13 ++++++-
 12 files changed, 74 insertions(+), 12 deletions(-)

I wrote this quickly and don't have an environment available to check it out
on.. Since it feels like a significant miss I felt we should start looking at
it.

diff --git a/drivers/vfio/device_cdev.c b/drivers/vfio/device_cdev.c
index 281a8dc3ed4974..c5d74c7e71f585 100644
--- a/drivers/vfio/device_cdev.c
+++ b/drivers/vfio/device_cdev.c
@@ -60,22 +60,50 @@ static void vfio_df_get_kvm_safe(struct vfio_device_file *df)
 	spin_unlock(&df->kvm_ref_lock);
 }
 
+static int vfio_df_check_token(struct vfio_device *device,
+			       const struct vfio_device_bind_iommufd *bind)
+{
+	uuid_t uuid;
+
+	if (!device->ops->match_token_uuid) {
+		if (bind->flags & VFIO_DEVICE_BIND_TOKEN)
+			return -EINVAL;
+		return 0;
+	}
+
+	if (!(bind->flags & VFIO_DEVICE_BIND_TOKEN))
+		return device->ops->match_token_uuid(device, NULL);
+
+	if (copy_from_user(&uuid, u64_to_user_ptr(bind->token_uuid_ptr),
+			   sizeof(uuid)))
+		return -EFAULT;
+	return device->ops->match_token_uuid(device, &uuid);
+}
+
 long vfio_df_ioctl_bind_iommufd(struct vfio_device_file *df,
 				struct vfio_device_bind_iommufd __user *arg)
 {
+	const u32 VALID_FLAGS = VFIO_DEVICE_BIND_TOKEN;
 	struct vfio_device *device = df->device;
 	struct vfio_device_bind_iommufd bind;
 	unsigned long minsz;
+	u32 user_size;
 	int ret;
 
 	static_assert(__same_type(arg->out_devid, df->devid));
 
 	minsz = offsetofend(struct vfio_device_bind_iommufd, out_devid);
 
-	if (copy_from_user(&bind, arg, minsz))
-		return -EFAULT;
+	ret = get_user(user_size, &arg->argsz);
+	if (ret)
+		return ret;
+	if (bind.argsz < minsz)
+		return -EINVAL;
+	ret = copy_struct_from_user(&bind, minsz, arg, user_size);
+	if (ret)
+		return ret;
 
-	if (bind.argsz < minsz || bind.flags || bind.iommufd < 0)
+	if (bind.iommufd < 0 || bind.flags & ~VALID_FLAGS)
 		return -EINVAL;
 
 	/* BIND_IOMMUFD only allowed for cdev fds */
@@ -93,6 +121,10 @@ long vfio_df_ioctl_bind_iommufd(struct vfio_device_file *df,
 		goto out_unlock;
 	}
 
+	ret = vfio_df_check_token(device, &bind);
+	if (ret)
+		return ret;
+
 	df->iommufd = iommufd_ctx_from_fd(bind.iommufd);
 	if (IS_ERR(df->iommufd)) {
 		ret = PTR_ERR(df->iommufd);
diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
index 2149f49aeec7f8..397f5e44513639 100644
--- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
+++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
@@ -1583,6 +1583,7 @@ static const struct vfio_device_ops hisi_acc_vfio_pci_ops = {
 	.mmap = vfio_pci_core_mmap,
 	.request = vfio_pci_core_request,
 	.match = vfio_pci_core_match,
+	.match_token_uuid = vfio_pci_core_match_token_uuid,
 	.bind_iommufd = vfio_iommufd_physical_bind,
 	.unbind_iommufd = vfio_iommufd_physical_unbind,
 	.attach_ioas = vfio_iommufd_physical_attach_ioas,
diff --git a/drivers/vfio/pci/mlx5/main.c b/drivers/vfio/pci/mlx5/main.c
index 93f894fe60d221..7ec47e736a8e5a 100644
--- a/drivers/vfio/pci/mlx5/main.c
+++ b/drivers/vfio/pci/mlx5/main.c
@@ -1372,6 +1372,7 @@ static const struct vfio_device_ops mlx5vf_pci_ops = {
 	.mmap = vfio_pci_core_mmap,
 	.request = vfio_pci_core_request,
 	.match = vfio_pci_core_match,
+	.match_token_uuid = vfio_pci_core_match_token_uuid,
 	.bind_iommufd = vfio_iommufd_physical_bind,
 	.unbind_iommufd = vfio_iommufd_physical_unbind,
 	.attach_ioas = vfio_iommufd_physical_attach_ioas,
diff --git a/drivers/vfio/pci/nvgrace-gpu/main.c b/drivers/vfio/pci/nvgrace-gpu/main.c
index e5ac39c4cc6b6f..d95761dcdd58c4 100644
--- a/drivers/vfio/pci/nvgrace-gpu/main.c
+++ b/drivers/vfio/pci/nvgrace-gpu/main.c
@@ -696,6 +696,7 @@ static const struct vfio_device_ops nvgrace_gpu_pci_ops = {
 	.mmap		= nvgrace_gpu_mmap,
 	.request	= vfio_pci_core_request,
 	.match		= vfio_pci_core_match,
+	.match_token_uuid = vfio_pci_core_match_token_uuid,
 	.bind_iommufd	= vfio_iommufd_physical_bind,
 	.unbind_iommufd	= vfio_iommufd_physical_unbind,
 	.attach_ioas	= vfio_iommufd_physical_attach_ioas,
@@ -715,6 +716,7 @@ static const struct vfio_device_ops nvgrace_gpu_pci_core_ops = {
 	.mmap		= vfio_pci_core_mmap,
 	.request	= vfio_pci_core_request,
 	.match		= vfio_pci_core_match,
+	.match_token_uuid = vfio_pci_core_match_token_uuid,
 	.bind_iommufd	= vfio_iommufd_physical_bind,
 	.unbind_iommufd	= vfio_iommufd_physical_unbind,
 	.attach_ioas	= vfio_iommufd_physical_attach_ioas,
diff --git a/drivers/vfio/pci/pds/vfio_dev.c b/drivers/vfio/pci/pds/vfio_dev.c
index 76a80ae7087b51..5731e6856deaf1 100644
--- a/drivers/vfio/pci/pds/vfio_dev.c
+++ b/drivers/vfio/pci/pds/vfio_dev.c
@@ -201,6 +201,7 @@ static const struct vfio_device_ops pds_vfio_ops = {
 	.mmap = vfio_pci_core_mmap,
 	.request = vfio_pci_core_request,
 	.match = vfio_pci_core_match,
+	.match_token_uuid = vfio_pci_core_match_token_uuid,
 	.bind_iommufd = vfio_iommufd_physical_bind,
 	.unbind_iommufd = vfio_iommufd_physical_unbind,
 	.attach_ioas = vfio_iommufd_physical_attach_ioas,
diff --git a/drivers/vfio/pci/qat/main.c b/drivers/vfio/pci/qat/main.c
index 845ed15b67718c..5cce6b0b8d2f3e 100644
--- a/drivers/vfio/pci/qat/main.c
+++ b/drivers/vfio/pci/qat/main.c
@@ -614,6 +614,7 @@ static const struct vfio_device_ops qat_vf_pci_ops = {
 	.mmap = vfio_pci_core_mmap,
 	.request = vfio_pci_core_request,
 	.match = vfio_pci_core_match,
+	.match_token_uuid = vfio_pci_core_match_token_uuid,
 	.bind_iommufd = vfio_iommufd_physical_bind,
 	.unbind_iommufd = vfio_iommufd_physical_unbind,
 	.attach_ioas = vfio_iommufd_physical_attach_ioas,
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index 5ba39f7623bb76..ac10f14417f2f3 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -138,6 +138,7 @@ static const struct vfio_device_ops vfio_pci_ops = {
 	.mmap		= vfio_pci_core_mmap,
 	.request	= vfio_pci_core_request,
 	.match		= vfio_pci_core_match,
+	.match_token_uuid = vfio_pci_core_match_token_uuid,
 	.bind_iommufd	= vfio_iommufd_physical_bind,
 	.unbind_iommufd	= vfio_iommufd_physical_unbind,
 	.attach_ioas	= vfio_iommufd_physical_attach_ioas,
diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
index 6328c3a05bcdd4..086aa37a60a2b5 100644
--- a/drivers/vfio/pci/vfio_pci_core.c
+++ b/drivers/vfio/pci/vfio_pci_core.c
@@ -1821,9 +1821,13 @@ void vfio_pci_core_request(struct vfio_device *core_vdev, unsigned int count)
 }
 EXPORT_SYMBOL_GPL(vfio_pci_core_request);
 
-static int vfio_pci_validate_vf_token(struct vfio_pci_core_device *vdev,
-				      bool vf_token, uuid_t *uuid)
+int vfio_pci_core_match_token_uuid(struct vfio_device *core_vdev,
+				   const uuid_t *uuid)
+
 {
+	struct vfio_pci_core_device *vdev =
+		container_of(core_vdev, struct vfio_pci_core_device, vdev);
+
 	/*
 	 * There's always some degree of trust or collaboration between SR-IOV
 	 * PF and VFs, even if just that the PF hosts the SR-IOV capability and
@@ -1854,7 +1858,7 @@ static int vfio_pci_validate_vf_token(struct vfio_pci_core_device *vdev,
 		bool match;
 
 		if (!pf_vdev) {
-			if (!vf_token)
+			if (!uuid)
 				return 0; /* PF is not vfio-pci, no VF token */
 
 			pci_info_ratelimited(vdev->pdev,
@@ -1862,7 +1866,7 @@ static int vfio_pci_validate_vf_token(struct vfio_pci_core_device *vdev,
 			return -EINVAL;
 		}
 
-		if (!vf_token) {
+		if (!uuid) {
 			pci_info_ratelimited(vdev->pdev,
 				"VF token required to access device\n");
 			return -EACCES;
@@ -1880,7 +1884,7 @@ static int vfio_pci_validate_vf_token(struct vfio_pci_core_device *vdev,
 	} else if (vdev->vf_token) {
 		mutex_lock(&vdev->vf_token->lock);
 		if (vdev->vf_token->users) {
-			if (!vf_token) {
+			if (!uuid) {
 				mutex_unlock(&vdev->vf_token->lock);
 				pci_info_ratelimited(vdev->pdev,
 					"VF token required to access device\n");
@@ -1893,12 +1897,12 @@ static int vfio_pci_validate_vf_token(struct vfio_pci_core_device *vdev,
 					"Incorrect VF token provided for device\n");
 				return -EACCES;
 			}
-		} else if (vf_token) {
+		} else if (uuid) {
 			uuid_copy(&vdev->vf_token->uuid, uuid);
 		}
 
 		mutex_unlock(&vdev->vf_token->lock);
-	} else if (vf_token) {
+	} else if (uuid) {
 		pci_info_ratelimited(vdev->pdev,
 			"VF token incorrectly provided, not a PF or VF\n");
 		return -EINVAL;
@@ -1906,6 +1910,7 @@ static int vfio_pci_validate_vf_token(struct vfio_pci_core_device *vdev,
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(vfio_pci_core_match_token_uuid);
 
 #define VF_TOKEN_ARG "vf_token="
 
@@ -1952,7 +1957,8 @@ int vfio_pci_core_match(struct vfio_device *core_vdev, char *buf)
 		}
 	}
 
-	ret = vfio_pci_validate_vf_token(vdev, vf_token, &uuid);
+	ret = vfio_pci_core_match_token_uuid(core_vdev,
+					     vf_token ? &uuid : NULL);
 	if (ret)
 		return ret;
 
diff --git a/drivers/vfio/pci/virtio/main.c b/drivers/vfio/pci/virtio/main.c
index 515fe1b9f94d80..8084f3e36a9f70 100644
--- a/drivers/vfio/pci/virtio/main.c
+++ b/drivers/vfio/pci/virtio/main.c
@@ -94,6 +94,7 @@ static const struct vfio_device_ops virtiovf_vfio_pci_lm_ops = {
 	.mmap = vfio_pci_core_mmap,
 	.request = vfio_pci_core_request,
 	.match = vfio_pci_core_match,
+	.match_token_uuid = vfio_pci_core_match_token_uuid,
 	.bind_iommufd = vfio_iommufd_physical_bind,
 	.unbind_iommufd = vfio_iommufd_physical_unbind,
 	.attach_ioas = vfio_iommufd_physical_attach_ioas,
@@ -114,6 +115,7 @@ static const struct vfio_device_ops virtiovf_vfio_pci_tran_lm_ops = {
 	.mmap = vfio_pci_core_mmap,
 	.request = vfio_pci_core_request,
 	.match = vfio_pci_core_match,
+	.match_token_uuid = vfio_pci_core_match_token_uuid,
 	.bind_iommufd = vfio_iommufd_physical_bind,
 	.unbind_iommufd = vfio_iommufd_physical_unbind,
 	.attach_ioas = vfio_iommufd_physical_attach_ioas,
@@ -134,6 +136,7 @@ static const struct vfio_device_ops virtiovf_vfio_pci_ops = {
 	.mmap = vfio_pci_core_mmap,
 	.request = vfio_pci_core_request,
 	.match = vfio_pci_core_match,
+	.match_token_uuid = vfio_pci_core_match_token_uuid,
 	.bind_iommufd = vfio_iommufd_physical_bind,
 	.unbind_iommufd = vfio_iommufd_physical_unbind,
 	.attach_ioas = vfio_iommufd_physical_attach_ioas,
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index 707b00772ce1ff..b2cca540a6b4bf 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -132,6 +132,7 @@ struct vfio_device_ops {
 	int	(*mmap)(struct vfio_device *vdev, struct vm_area_struct *vma);
 	void	(*request)(struct vfio_device *vdev, unsigned int count);
 	int	(*match)(struct vfio_device *vdev, char *buf);
+	int	(*match_token_uuid)(struct vfio_device *vdev, const uuid_t *uuid);
 	void	(*dma_unmap)(struct vfio_device *vdev, u64 iova, u64 length);
 	int	(*device_feature)(struct vfio_device *device, u32 flags,
 				  void __user *arg, size_t argsz);
diff --git a/include/linux/vfio_pci_core.h b/include/linux/vfio_pci_core.h
index fbb472dd99b361..f541044e42a2ad 100644
--- a/include/linux/vfio_pci_core.h
+++ b/include/linux/vfio_pci_core.h
@@ -122,6 +122,8 @@ ssize_t vfio_pci_core_write(struct vfio_device *core_vdev, const char __user *bu
 int vfio_pci_core_mmap(struct vfio_device *core_vdev, struct vm_area_struct *vma);
 void vfio_pci_core_request(struct vfio_device *core_vdev, unsigned int count);
 int vfio_pci_core_match(struct vfio_device *core_vdev, char *buf);
+int vfio_pci_core_match_token_uuid(struct vfio_device *core_vdev,
+				   const uuid_t *uuid);
 int vfio_pci_core_enable(struct vfio_pci_core_device *vdev);
 void vfio_pci_core_disable(struct vfio_pci_core_device *vdev);
 void vfio_pci_core_finish_enable(struct vfio_pci_core_device *vdev);
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index 5764f315137f99..48233ec4daf7b4 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -901,14 +901,18 @@ struct vfio_device_feature {
 
 #define VFIO_DEVICE_FEATURE		_IO(VFIO_TYPE, VFIO_BASE + 17)
 
+#define VFIO_DEVICE_BIND_TOKEN (1 << 0)
+
 /*
  * VFIO_DEVICE_BIND_IOMMUFD - _IOR(VFIO_TYPE, VFIO_BASE + 18,
  *				   struct vfio_device_bind_iommufd)
  * @argsz:	 User filled size of this data.
- * @flags:	 Must be 0.
+ * @flags:	 Must be 0 or a bit flags of VFIO_DEVICE_BIND_*
  * @iommufd:	 iommufd to bind.
  * @out_devid:	 The device id generated by this bind. devid is a handle for
  *		 this device/iommufd bond and can be used in IOMMUFD commands.
+ * @token_uuid_ptr: Valid if VFIO_DEVICE_BIND_TOKEN. Points to a 16 byte UUID
+ *                  in the same format as VFIO_DEVICE_FEATURE_PCI_VF_TOKEN.
  *
  * Bind a vfio_device to the specified iommufd.
  *
@@ -917,6 +921,12 @@ struct vfio_device_feature {
  *
  * Unbind is automatically conducted when device fd is closed.
  *
+ * A token is sometimes required to open the device, unless this is known to be
+ * needed VFIO_DEVICE_BIND_TOKEN should not be set and token_uuid_ptr is
+ * ignored. The only case today is a PF/VF relationship where the VF bind must
+ * be provided the same token as VFIO_DEVICE_FEATURE_PCI_VF_TOKEN provided to
+ * the PF.
+ *
  * Return: 0 on success, -errno on failure.
  */
 struct vfio_device_bind_iommufd {
@@ -924,6 +934,7 @@ struct vfio_device_bind_iommufd {
 	__u32		flags;
 	__s32		iommufd;
 	__u32		out_devid;
+	__aligned_u64	token_uuid_ptr;
 };
 
 #define VFIO_DEVICE_BIND_IOMMUFD	_IO(VFIO_TYPE, VFIO_BASE + 18)

base-commit: 3e2a9811f6a9cefd310cc33cab73d5435b4a4caa
-- 
2.43.0


^ permalink raw reply related	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2025-07-10  8:30 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-06-24 18:34 [PATCH] vfio/pci: Do vf_token checks for VFIO_DEVICE_BIND_IOMMUFD Jason Gunthorpe
2025-06-24 20:06 ` Alex Williamson
2025-07-02 14:56   ` Jason Gunthorpe
2025-07-03  6:40 ` Tian, Kevin
2025-07-03 13:41   ` Jason Gunthorpe
2025-07-10  8:29     ` Tian, Kevin

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