> -----Original Message-----
> From: Jason Gunthorpe <jgg@xxxxxxxxxx>
> Sent: Thursday, July 10, 2025 4:30 PM
> To: Ankit Agrawal <ankita@xxxxxxxxxx>; Brett Creeley
> <brett.creeley@xxxxxxx>; Giovanni Cabiddu
> <giovanni.cabiddu@xxxxxxxxx>; Kevin Tian <kevin.tian@xxxxxxxxx>;
> kvm@xxxxxxxxxxxxxxx; liulongfang <liulongfang@xxxxxxxxxx>; qat-
> linux@xxxxxxxxx; virtualization@xxxxxxxxxxxxxxx; Xin Zeng
> <xin.zeng@xxxxxxxxx>; Yishai Hadas <yishaih@xxxxxxxxxx>
> Cc: Alex Williamson <alex.williamson@xxxxxxxxxx>; Matthew Rosato
> <mjrosato@xxxxxxxxxxxxx>; Nicolin Chen <nicolinc@xxxxxxxxxx>;
> patches@xxxxxxxxxxxxxxx; Shameerali Kolothum Thodi
> <shameerali.kolothum.thodi@xxxxxxxxxx>; Terrence Xu
> <terrence.xu@xxxxxxxxx>; Yanting Jiang <yanting.jiang@xxxxxxxxx>; Yi Liu
> <yi.l.liu@xxxxxxxxx>; Zhenzhong Duan <zhenzhong.duan@xxxxxxxxx>
> Subject: [PATCH v2] vfio/pci: Do vf_token checks for
> VFIO_DEVICE_BIND_IOMMUFD
>
> 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 through
> VFIO_DEVICE_BIND_IOMMUFD using an optional field indicated by
> VFIO_DEVICE_BIND_TOKEN.
>
> Fixes: 5fcc26969a16 ("vfio: Add VFIO_DEVICE_BIND_IOMMUFD")
> Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
> ---
> 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 | 4 ++
> include/linux/vfio_pci_core.h | 2 +
> include/uapi/linux/vfio.h | 12 +++++-
> 12 files changed, 76 insertions(+), 12 deletions(-)
>
> v2:
> - Revise VFIO_DEVICE_BIND_TOKEN -> VFIO_DEVICE_BIND_FLAG_TOKEN
> - Call the match_token_uuid through ops instead of directly
> - update comments/style
> v1: https://patch.msgid.link/r/0-v1-8639f9aed215+853-
> vfio_token_jgg@xxxxxxxxxx
>
> diff --git a/drivers/vfio/device_cdev.c b/drivers/vfio/device_cdev.c
> index 281a8dc3ed4974..1c96d3627be24b 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_FLAG_TOKEN)
> + return -EINVAL;
> + return 0;
> + }
> +
> + if (!(bind->flags & VFIO_DEVICE_BIND_FLAG_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_FLAG_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)
The above check should use user_size.
With that fixed, I did a basic sanity testing with a latest Qemu(no BIND_FLAG_TOKEN flag),
assigning a vf to a Guest. Seems to be OK. No regression observed.
FWIW:
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@xxxxxxxxxx>
Thanks,
Shameer
> + 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..d39b0201d910fd 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 = core_vdev->ops->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..eb563f538dee51 100644
> --- a/include/linux/vfio.h
> +++ b/include/linux/vfio.h
> @@ -105,6 +105,9 @@ struct vfio_device {
> * @match: Optional device name match callback (return: 0 for no-match,
> >0 for
> * match, -errno for abort (ex. match with insufficient or incorrect
> * additional args)
> + * @match_token_uuid: Optional device token match/validation. Return 0
> + * if the uuid is valid for the device, -errno otherwise. uuid is NULL
> + * if none was provided.
> * @dma_unmap: Called when userspace unmaps IOVA from the container
> * this device is attached to.
> * @device_feature: Optional, fill in the VFIO_DEVICE_FEATURE ioctl
> @@ -132,6 +135,7 @@ 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..75100bf009baf5 100644
> --- a/include/uapi/linux/vfio.h
> +++ b/include/uapi/linux/vfio.h
> @@ -905,10 +905,12 @@ struct vfio_device_feature {
> * 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_FLAG_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.
> *
> @@ -917,13 +919,21 @@ 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_FLAG_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 {
> __u32 argsz;
> __u32 flags;
> +#define VFIO_DEVICE_BIND_FLAG_TOKEN (1 << 0)
> __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
