On Fri, Jan 12, 2024 at 12:18 AM Mike Christie
<michael.christie@xxxxxxxxxx> wrote:
>
> On 1/10/24 9:09 PM, Jason Wang wrote:
> > On Thu, Jan 11, 2024 at 4:40 AM Steve Sistare <steven.sistare@xxxxxxxxxx> wrote:
> >>
> >> To pass ownership of a live vdpa device to a new process, the user
> >> suspends the device, calls VHOST_NEW_OWNER to change the mm, and calls
> >> VHOST_IOTLB_REMAP to change the user virtual addresses to match the new
> >> mm. Flush workers in suspend to guarantee that no worker sees the new
> >> mm and old VA in between.
> >>
> >> Signed-off-by: Steve Sistare <steven.sistare@xxxxxxxxxx>
> >> ---
> >> drivers/vhost/vdpa.c | 4 ++++
> >> 1 file changed, 4 insertions(+)
> >>
> >> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> >> index 8fe1562d24af..9673e8e20d11 100644
> >> --- a/drivers/vhost/vdpa.c
> >> +++ b/drivers/vhost/vdpa.c
> >> @@ -591,10 +591,14 @@ static long vhost_vdpa_suspend(struct vhost_vdpa *v)
> >> {
> >> struct vdpa_device *vdpa = v->vdpa;
> >> const struct vdpa_config_ops *ops = vdpa->config;
> >> + struct vhost_dev *vdev = &v->vdev;
> >>
> >> if (!ops->suspend)
> >> return -EOPNOTSUPP;
> >>
> >> + if (vdev->use_worker)
> >> + vhost_dev_flush(vdev);
> >
> > It looks to me like it's better to check use_woker in vhost_dev_flush.
> >
>
> You can now just call vhost_dev_flush and it will do the right thing.
> The xa_for_each loop will only flush workers if they have been setup,
> so for vdpa it will not find/flush anything.
Right.
Thanks
>
>
>
