On Thu, Nov 07, 2019 at 12:08:08PM +0800, Jason Wang wrote: > On 2019/11/6 下午10:49, Tiwei Bie wrote: > > > > > > > + default: > > > > > > > + /* > > > > > > > + * VHOST_SET_MEM_TABLE, VHOST_SET_LOG_BASE, and > > > > > > > + * VHOST_SET_LOG_FD are not used yet. > > > > > > > + */ > > > > > > If we don't even use them, there's probably no need to call > > > > > > vhost_dev_ioctl(). This may help to avoid confusion when we want to develop > > > > > > new API for e.g dirty page tracking. > > > > > Good point. It's better to reject these ioctls for now. > > > > > > > > > > PS. One thing I may need to clarify is that, we need the > > > > > VHOST_SET_OWNER ioctl to get the vq->handle_kick to work. > > > > > So if we don't call vhost_dev_ioctl(), we will need to > > > > > call vhost_dev_set_owner() directly. > > > I may miss something, it looks to me the there's no owner check in > > > vhost_vring_ioctl() and the vhost_poll_start() can make sure handle_kick > > > works? > > Yeah, there is no owner check in vhost_vring_ioctl(). > > IIUC, vhost_poll_start() will start polling the file. And when > > event arrives, vhost_poll_wakeup() will be called, and it will > > queue work to work_list and wakeup worker to finish the work. > > And the worker is created by vhost_dev_set_owner(). > > > > Right, rethink about this. It looks to me we need: > > - Keep VHOST_SET_OWNER, this could be used for future control vq where it > needs a kthread to access the userspace memory > > - Temporarily filter SET_LOG_BASE and SET_LOG_FD until we finalize the API > for dirty page tracking. > > - For kick through kthread, it looks sub-optimal but we can address this in > the future, e.g call handle_vq_kick directly in vhost_poll_queue (probably a > flag for vhost_poll) and deal with the synchronization in vhost_poll_flush > carefully. OK. Thanks, Tiwei > > Thanks > >
