On Thu, 31 Jan 2019 10:27:53 -0500 "Michael S. Tsirkin" <mst@xxxxxxxxxx> wrote: > On Thu, Jan 31, 2019 at 01:53:14PM +0100, Cornelia Huck wrote: > > A virtio transport is free to implement some of the callbacks in > > virtio_config_ops in a matter that they cannot be called from > > atomic context (e.g. virtio-ccw, which maps a lot of the callbacks > > to channel I/O, which is an inherently asynchronous mechanism). > > This can be very surprising for developers using the much more > > common virtio-pci transport, just to find out that things break > > when used on s390. > > > > The documentation for virtio_config_ops now contains a comment > > explaining this, but it makes sense to add a might_sleep() annotation > > to various wrapper functions in the virtio core to avoid surprises > > later. > > > > Note that annotations are NOT added to two classes of calls: > > - direct calls from device drivers (all current callers should be > > fine, however) > > - calls which clearly won't be made from atomic context (such as > > those ultimately coming in via the driver core) > > > > Signed-off-by: Cornelia Huck <cohuck@xxxxxxxxxx> > > > Makes sense to me. I don't think we should push our luck in > this release though, better defer until the merge window. Nod, that's definitely something for the next release.
