[PATCH 2/3] vfio: Add VFIO_DEVICE_PASID_[AT|DE]TACH_IOMMUFD_PT

Yi Liu
2023-11-27T06:39:13Z

This adds ioctls for the userspace to attach a given pasid of a vfio
device to/from an IOAS/HWPT.

Signed-off-by: Yi Liu <yi.l.liu@intel.com>
---
drivers/vfio/device_cdev.c | 45 +++++++++++++++++++++++++++++++
drivers/vfio/vfio.h | 4 +++
drivers/vfio/vfio_main.c | 8 ++++++
include/uapi/linux/vfio.h | 55 ++++++++++++++++++++++++++++++++++++++
4 files changed, 112 insertions(+)

diff --git a/drivers/vfio/device_cdev.c b/drivers/vfio/device_cdev.c
index e75da0a70d1f..c2ac7ed44537 100644
--- a/drivers/vfio/device_cdev.c
+++ b/drivers/vfio/device_cdev.c
@@ -210,6 +210,51 @@ int vfio_df_ioctl_detach_pt(struct vfio_device_file *df,
return 0;
}

+int vfio_df_ioctl_pasid_attach_pt(struct vfio_device_file *df,
+ struct vfio_device_pasid_attach_iommufd_pt __user *arg)
+{
+ struct vfio_device *device = df->device;
+ struct vfio_device_pasid_attach_iommufd_pt attach;
+ unsigned long minsz;
+ int ret;
+
+ minsz = offsetofend(struct vfio_device_pasid_attach_iommufd_pt, pt_id);
+
+ if (copy_from_user(&attach, arg, minsz))
+ return -EFAULT;
+
+ if (attach.argsz < minsz || attach.flags)
+ return -EINVAL;
+
+ mutex_lock(&device->dev_set->lock);
+ ret = device->ops->pasid_attach_ioas(device, attach.pasid, &attach.pt_id);
+ mutex_unlock(&device->dev_set->lock);
+
+ return ret;
+}
+
+int vfio_df_ioctl_pasid_detach_pt(struct vfio_device_file *df,
+ struct vfio_device_pasid_detach_iommufd_pt __user *arg)
+{
+ struct vfio_device *device = df->device;
+ struct vfio_device_pasid_detach_iommufd_pt detach;
+ unsigned long minsz;
+
+ minsz = offsetofend(struct vfio_device_pasid_detach_iommufd_pt, flags);
+
+ if (copy_from_user(&detach, arg, minsz))
+ return -EFAULT;
+
+ if (detach.argsz < minsz || detach.flags)
+ return -EINVAL;
+
+ mutex_lock(&device->dev_set->lock);
+ device->ops->pasid_detach_ioas(device, detach.pasid);
+ mutex_unlock(&device->dev_set->lock);
+
+ return 0;
+}
+
static char *vfio_device_devnode(const struct device *dev, umode_t *mode)
{
return kasprintf(GFP_KERNEL, "vfio/devices/%s", dev_name(dev));
diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h
index 307e3f29b527..d228cdb6b345 100644
--- a/drivers/vfio/vfio.h
+++ b/drivers/vfio/vfio.h
@@ -353,6 +353,10 @@ int vfio_df_ioctl_attach_pt(struct vfio_device_file *df,
struct vfio_device_attach_iommufd_pt __user *arg);
int vfio_df_ioctl_detach_pt(struct vfio_device_file *df,
struct vfio_device_detach_iommufd_pt __user *arg);
+int vfio_df_ioctl_pasid_attach_pt(struct vfio_device_file *df,
+ struct vfio_device_pasid_attach_iommufd_pt __user *arg);
+int vfio_df_ioctl_pasid_detach_pt(struct vfio_device_file *df,
+ struct vfio_device_pasid_detach_iommufd_pt __user *arg);

#if IS_ENABLED(CONFIG_VFIO_DEVICE_CDEV)
void vfio_init_device_cdev(struct vfio_device *device);
diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
index 8d4995ada74a..ff50c239873d 100644
--- a/drivers/vfio/vfio_main.c
+++ b/drivers/vfio/vfio_main.c
@@ -1240,6 +1240,14 @@ static long vfio_device_fops_unl_ioctl(struct file *filep,
case VFIO_DEVICE_DETACH_IOMMUFD_PT:
ret = vfio_df_ioctl_detach_pt(df, uptr);
goto out;
+
+ case VFIO_DEVICE_PASID_ATTACH_IOMMUFD_PT:
+ ret = vfio_df_ioctl_pasid_attach_pt(df, uptr);
+ goto out;
+
+ case VFIO_DEVICE_PASID_DETACH_IOMMUFD_PT:
+ ret = vfio_df_ioctl_pasid_detach_pt(df, uptr);
+ goto out;
}
}

diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index 94b3badefde3..495193629029 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -977,6 +977,61 @@ struct vfio_device_detach_iommufd_pt {

#define VFIO_DEVICE_DETACH_IOMMUFD_PT _IO(VFIO_TYPE, VFIO_BASE + 20)

+/*
+ * VFIO_DEVICE_PASID_ATTACH_IOMMUFD_PT - _IOW(VFIO_TYPE, VFIO_BASE + 21,
+ * struct vfio_device_pasid_attach_iommufd_pt)
+ * @argsz: User filled size of this data.
+ * @flags: Must be 0.
+ * @pasid: The pasid to be attached.
+ * @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.
+ *
+ * Associate a pasid (of a cdev device) with an address space within the
+ * bound iommufd. Undo by VFIO_DEVICE_PASID_DETACH_IOMMUFD_PT or device fd
+ * close. This is only allowed on cdev fds.
+ *
+ * If a pasid is currently attached to a valid hw_pagetable (hwpt), without
+ * doing a VFIO_DEVICE_PASID_DETACH_IOMMUFD_PT, a second
+ * VFIO_DEVICE_PASID_ATTACH_IOMMUFD_PT ioctl passing in another hwpt id is
+ * allowed. This action, also known as a hwpt replacement, will replace the
+ * pasid's currently attached hwpt with a new hwpt corresponding to the given
+ * @pt_id.
+ *
+ * Return: 0 on success, -errno on failure.
+ */
+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)
+
+/*
+ * VFIO_DEVICE_PASID_DETACH_IOMMUFD_PT - _IOW(VFIO_TYPE, VFIO_BASE + 22,
+ * struct vfio_device_pasid_detach_iommufd_pt)
+ * @argsz: User filled size of this data.
+ * @flags: Must be 0.
+ * @pasid: The pasid to be detached.
+ *
+ * Remove the association of a pasid (of a cdev device) and its current
+ * associated address space. After it, the pasid of the device should be in
+ * a blocking DMA state. This is only allowed on cdev fds.
+ *
+ * Return: 0 on success, -errno on failure.
+ */
+struct vfio_device_pasid_detach_iommufd_pt {
+ __u32 argsz;
+ __u32 flags;
+ __u32 pasid;
+};
+
+#define VFIO_DEVICE_PASID_DETACH_IOMMUFD_PT _IO(VFIO_TYPE, VFIO_BASE + 22)
+
/*
* Provide support for setting a PCI VF Token, which is used as a shared
* secret between PF and VF drivers. This feature may only be set on a
--
2.34.1