On 2024/11/12 08:02, Alex Williamson wrote:
On Fri, 8 Nov 2024 04:17:40 -0800
Yi Liu <yi.l.liu@xxxxxxxxx> wrote:
This extends the VFIO_DEVICE_[AT|DE]TACH_IOMMUFD_PT ioctls to attach/detach
a given pasid of a vfio device to/from an IOAS/HWPT.
Signed-off-by: Yi Liu <yi.l.liu@xxxxxxxxx>
---
drivers/vfio/device_cdev.c | 69 +++++++++++++++++++++++++++++++++-----
include/uapi/linux/vfio.h | 29 ++++++++++------
2 files changed, 80 insertions(+), 18 deletions(-)
diff --git a/drivers/vfio/device_cdev.c b/drivers/vfio/device_cdev.c
index bb1817bd4ff3..4519f482e212 100644
--- a/drivers/vfio/device_cdev.c
+++ b/drivers/vfio/device_cdev.c
@@ -162,9 +162,9 @@ void vfio_df_unbind_iommufd(struct vfio_device_file *df)
int vfio_df_ioctl_attach_pt(struct vfio_device_file *df,
struct vfio_device_attach_iommufd_pt __user *arg)
{
- struct vfio_device *device = df->device;
struct vfio_device_attach_iommufd_pt attach;
- unsigned long minsz;
+ struct vfio_device *device = df->device;
+ unsigned long minsz, xend = 0;
int ret;
minsz = offsetofend(struct vfio_device_attach_iommufd_pt, pt_id);
@@ -172,11 +172,38 @@ int vfio_df_ioctl_attach_pt(struct vfio_device_file *df,
if (copy_from_user(&attach, arg, minsz))
return -EFAULT;
- if (attach.argsz < minsz || attach.flags)
+ if (attach.argsz < minsz)
return -EINVAL;
+ if (attach.flags & (~VFIO_DEVICE_ATTACH_PASID))
+ return -EINVAL;
+
+ if (attach.flags & VFIO_DEVICE_ATTACH_PASID)
+ xend = offsetofend(struct vfio_device_attach_iommufd_pt, pasid);
+
+ /*
+ * xend may be equal to minsz if a flag is defined for reusing a
+ * reserved field or a special usage of an existing field.
+ */
+ if (xend > minsz) {
+ if (attach.argsz < xend)
+ return -EINVAL;
+
+ if (copy_from_user((void *)&attach + minsz,
+ (void __user *)arg + minsz, xend - minsz))
+ return -EFAULT;
+ }
+
+ if ((attach.flags & VFIO_DEVICE_ATTACH_PASID) &&
+ !device->ops->pasid_attach_ioas)
+ return -EOPNOTSUPP;
+
mutex_lock(&device->dev_set->lock);
- ret = device->ops->attach_ioas(device, &attach.pt_id);
+ if (attach.flags & VFIO_DEVICE_ATTACH_PASID)
I'd just do the ops test here:
{
if (!device->ops->pasid_attach_ios)
ret = -EOPNOTSUPP;
else...
+ ret = device->ops->pasid_attach_ioas(device, attach.pasid,
+ &attach.pt_id);
got it.
} else {
(Obviously if we weren't about to generalize the prior chunk of code,
we'd test ops before the 2nd copy_from_user) Thanks,
yes. that's the trade-off for the generalization. :)
--
Regards,
Yi Liu
