On 2024/10/14 23:49, Alex Williamson wrote:
On Sat, 12 Oct 2024 21:49:05 +0800
Yi Liu <yi.l.liu@xxxxxxxxx> wrote:
On 2024/10/1 20:11, Jason Gunthorpe wrote:
On Mon, Sep 30, 2024 at 07:55:08AM +0000, Tian, Kevin wrote:
+struct vfio_device_pasid_attach_iommufd_pt {
+ __u32 argsz;
+ __u32 flags;
+ __u32 pasid;
+ __u32 pt_id;
+};
+
+#define VFIO_DEVICE_PASID_ATTACH_IOMMUFD_PT _IO(VFIO_TYPE,
VFIO_BASE + 21)
Not sure whether this was discussed before. Does it make sense
to reuse the existing VFIO_DEVICE_ATTACH_IOMMUFD_PT
by introducing a new pasid field and a new flag bit?
Maybe? I don't have a strong feeling either way.
There is somewhat less code if you reuse the ioctl at least
I had a rough memory that I was suggested to add a separate ioctl for
PASID. Let's see Alex's opinion.
I don't recall any previous arguments for separate ioctls, but it seems
to make a lot of sense to me to extend the existing ioctls with a flag
to indicate pasid cscope and id. Thanks,
thanks for the confirmation. How about the below?
diff --git a/drivers/vfio/device_cdev.c b/drivers/vfio/device_cdev.c
index bb1817bd4ff3..c78533bce3c6 100644
--- a/drivers/vfio/device_cdev.c
+++ b/drivers/vfio/device_cdev.c
@@ -162,21 +162,34 @@ 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;
+ unsigned long minsz = offsetofend(
+ struct vfio_device_attach_iommufd_pt, pt_id);
struct vfio_device_attach_iommufd_pt attach;
- unsigned long minsz;
+ struct vfio_device *device = df->device;
+ u32 user_size;
int ret;
- minsz = offsetofend(struct vfio_device_attach_iommufd_pt, pt_id);
+ ret = get_user(user_size, (u32 __user *)arg);
+ if (ret)
+ return ret;
- if (copy_from_user(&attach, arg, minsz))
- return -EFAULT;
+ ret = copy_struct_from_user(&attach, sizeof(attach), arg, user_size);
+ if (ret)
+ return ret;
- if (attach.argsz < minsz || attach.flags)
+ if (attach.argsz < minsz || attach.flags & (~VFIO_DEVICE_ATTACH_PASID))
return -EINVAL;
+ 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)
+ ret = device->ops->pasid_attach_ioas(device, attach.pasid,
+ &attach.pt_id);
+ else
+ ret = device->ops->attach_ioas(device, &attach.pt_id);
if (ret)
goto out_unlock;
@@ -198,20 +211,33 @@ int vfio_df_ioctl_attach_pt(struct vfio_device_file *df,
int vfio_df_ioctl_detach_pt(struct vfio_device_file *df,
struct vfio_device_detach_iommufd_pt __user *arg)
{
- struct vfio_device *device = df->device;
+ unsigned long minsz =
+ offsetofend(struct vfio_device_detach_iommufd_pt, flags);
struct vfio_device_detach_iommufd_pt detach;
- unsigned long minsz;
+ struct vfio_device *device = df->device;
+ u32 user_size;
+ int ret;
- minsz = offsetofend(struct vfio_device_detach_iommufd_pt, flags);
+ ret = get_user(user_size, (u32 __user *)arg);
+ if (ret)
+ return ret;
- if (copy_from_user(&detach, arg, minsz))
- return -EFAULT;
+ ret = copy_struct_from_user(&detach, sizeof(detach), arg, user_size);
+ if (ret)
+ return ret;
- if (detach.argsz < minsz || detach.flags)
+ if (detach.argsz < minsz || detach.flags & (~VFIO_DEVICE_DETACH_PASID))
return -EINVAL;
+ if ((detach.flags & VFIO_DEVICE_DETACH_PASID) &&
+ !device->ops->pasid_detach_ioas)
+ return -EOPNOTSUPP;
+
mutex_lock(&device->dev_set->lock);
- device->ops->detach_ioas(device);
+ if (detach.flags & VFIO_DEVICE_DETACH_PASID)
+ device->ops->pasid_detach_ioas(device, detach.pasid);
+ else
+ device->ops->detach_ioas(device);
mutex_unlock(&device->dev_set->lock);
return 0;
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index 2b68e6cdf190..40b414e642f5 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -931,29 +931,34 @@ struct vfio_device_bind_iommufd {
* VFIO_DEVICE_ATTACH_IOMMUFD_PT - _IOW(VFIO_TYPE, VFIO_BASE + 19,
* struct vfio_device_attach_iommufd_pt)
* @argsz: User filled size of this data.
- * @flags: Must be 0.
+ * @flags: Flags for attach.
* @pt_id: Input the target id which can represent an ioas or a hwpt
* allocated via iommufd subsystem.
* Output the input ioas id or the attached hwpt id which could
* be the specified hwpt itself or a hwpt automatically created
* for the specified ioas by kernel during the attachment.
+ * @pasid: The pasid to be attached, only meaningful when
+ * VFIO_DEVICE_ATTACH_PASID is set in @flags
*
* Associate the device with an address space within the bound iommufd.
* Undo by VFIO_DEVICE_DETACH_IOMMUFD_PT or device fd close. This is only
* allowed on cdev fds.
*
- * If a vfio device is currently attached to a valid hw_pagetable, without
doing
- * a VFIO_DEVICE_DETACH_IOMMUFD_PT, a second VFIO_DEVICE_ATTACH_IOMMUFD_PT
ioctl
- * passing in another hw_pagetable (hwpt) id is allowed. This action, also
known
- * as a hw_pagetable replacement, will replace the device's currently attached
- * hw_pagetable with a new hw_pagetable corresponding to the given pt_id.
+ * If a vfio device or a pasid of this device is currently attached to a valid
+ * hw_pagetable (hwpt), without doing a VFIO_DEVICE_DETACH_IOMMUFD_PT, a
second
+ * VFIO_DEVICE_ATTACH_IOMMUFD_PT ioctl passing in another hwpt id is allowed.
+ * This action, also known as a hw_pagetable replacement, will replace the
+ * currently attached hwpt of the device or the pasid of this device with
a new
+ * hwpt corresponding to the given pt_id.
*
* Return: 0 on success, -errno on failure.
*/
struct vfio_device_attach_iommufd_pt {
__u32 argsz;
__u32 flags;
+#define VFIO_DEVICE_ATTACH_PASID (1 << 0)
__u32 pt_id;
+ __u32 pasid;
};
#define VFIO_DEVICE_ATTACH_IOMMUFD_PT _IO(VFIO_TYPE, VFIO_BASE + 19)
@@ -962,17 +967,21 @@ struct vfio_device_attach_iommufd_pt {
* VFIO_DEVICE_DETACH_IOMMUFD_PT - _IOW(VFIO_TYPE, VFIO_BASE + 20,
* struct vfio_device_detach_iommufd_pt)
* @argsz: User filled size of this data.
- * @flags: Must be 0.
+ * @flags: Flags for detach.
+ * @pasid: The pasid to be detached, only meaningful when
+ * VFIO_DEVICE_DETACH_PASID is set in @flags
*
- * Remove the association of the device and its current associated address
- * space. After it, the device should be in a blocking DMA state. This
is only
- * allowed on cdev fds.
+ * Remove the association of the device or a pasid of the device and its
current
+ * associated address space. After it, the device or the pasid should be in a
+ * blocking DMA state. This is only allowed on cdev fds.
*
* Return: 0 on success, -errno on failure.
*/
struct vfio_device_detach_iommufd_pt {
__u32 argsz;
__u32 flags;
+#define VFIO_DEVICE_DETACH_PASID (1 << 0)
+ __u32 pasid;
};
#define VFIO_DEVICE_DETACH_IOMMUFD_PT _IO(VFIO_TYPE, VFIO_BASE + 20)
--
2.34.1
--
Regards,
Yi Liu
