[PATCH v3 2/8] vhost-vdpa: use bind_mm/unbind_mm device callbacks

Stefano Garzarella
2023-03-21T15:43:46Z

When the user call VHOST_SET_OWNER ioctl and the vDPA device
has `use_va` set to true, let's call the bind_mm callback.
In this way we can bind the device to the user address space
and directly use the user VA.

The unbind_mm callback is called during the release after
stopping the device.

Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
---

Notes:
v3:
- added `case VHOST_SET_OWNER` in vhost_vdpa_unlocked_ioctl() [Jason]
v2:
- call the new unbind_mm callback during the release [Jason]
- avoid to call bind_mm callback after the reset, since the device
is not detaching it now during the reset

drivers/vhost/vdpa.c | 31 +++++++++++++++++++++++++++++++
1 file changed, 31 insertions(+)

diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index 7be9d9d8f01c..20250c3418b2 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -219,6 +219,28 @@ static int vhost_vdpa_reset(struct vhost_vdpa *v)
return vdpa_reset(vdpa);
}

+static long vhost_vdpa_bind_mm(struct vhost_vdpa *v)
+{
+ struct vdpa_device *vdpa = v->vdpa;
+ const struct vdpa_config_ops *ops = vdpa->config;
+
+ if (!vdpa->use_va || !ops->bind_mm)
+ return 0;
+
+ return ops->bind_mm(vdpa, v->vdev.mm);
+}
+
+static void vhost_vdpa_unbind_mm(struct vhost_vdpa *v)
+{
+ struct vdpa_device *vdpa = v->vdpa;
+ const struct vdpa_config_ops *ops = vdpa->config;
+
+ if (!vdpa->use_va || !ops->unbind_mm)
+ return;
+
+ ops->unbind_mm(vdpa);
+}
+
static long vhost_vdpa_get_device_id(struct vhost_vdpa *v, u8 __user *argp)
{
struct vdpa_device *vdpa = v->vdpa;
@@ -709,6 +731,14 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep,
case VHOST_VDPA_RESUME:
r = vhost_vdpa_resume(v);
break;
+ case VHOST_SET_OWNER:
+ r = vhost_dev_set_owner(d);
+ if (r)
+ break;
+ r = vhost_vdpa_bind_mm(v);
+ if (r)
+ vhost_dev_reset_owner(d, NULL);
+ break;
default:
r = vhost_dev_ioctl(&v->vdev, cmd, argp);
if (r == -ENOIOCTLCMD)
@@ -1287,6 +1317,7 @@ static int vhost_vdpa_release(struct inode *inode, struct file *filep)
vhost_vdpa_clean_irq(v);
vhost_vdpa_reset(v);
vhost_dev_stop(&v->vdev);
+ vhost_vdpa_unbind_mm(v);
vhost_vdpa_config_put(v);
vhost_vdpa_cleanup(v);
mutex_unlock(&d->mutex);
--
2.39.2