On Sun, Sep 09, 2012 at 02:36:50PM +0300, Michael S. Tsirkin wrote: > Drivers treat MUST_TELL_HOST as optional: windows drivers do not ack it > and expect this means they can tell host *after* deflate. This was not > the intent but the documentation was not very clear on this point. > > Luckily hyprevisors did not implement this feature yet so to provide > guidance for future devices make spec match drivers expectations, and > clarify that this feature only has effect if negotiated. > This is needed as recent developments in kvm (memory > region rework and the addition of vfio) finally make > it practical to implement this in devices. > > Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx> Acked-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> ping > --- > > OK how about this minimal patch for starters? > Other changes are possible on top but I think > both me and Paolo agree on this one. > Paolo? > > virtio-spec.lyx | 20 +++++++++++++++----- > 1 file changed, 15 insertions(+), 5 deletions(-) > > diff --git a/virtio-spec.lyx b/virtio-spec.lyx > index d801aa6..d9626a9 100644 > --- a/virtio-spec.lyx > +++ b/virtio-spec.lyx > @@ -6331,8 +6331,13 @@ VIRTIO_CONSOLE_F_SIZE > > \begin_layout Description > VIRTIO_CONSOLE_F_MULTIPORT(1) Device has support for multiple ports; configurati > -on fields nr_ports and max_nr_ports are valid and control virtqueues will > - be used. > +on fields nr_ports and max_nr_ports are valid > +\change_inserted 1986246365 1347188404 > +; if this bit is negotiated, > +\change_deleted 1986246365 1347188406 > + and > +\change_unchanged > + control virtqueues will be used. > \end_layout > > \end_deeper > @@ -6840,9 +6845,14 @@ The driver constructs an array of addresses of memory pages it has previously > \end_layout > > \begin_layout Enumerate > -If the VIRTIO_BALLOON_F_MUST_TELL_HOST feature is set, the guest may not > - use these requested pages until that descriptor in the deflateq has been > - used by the device. > +If the VIRTIO_BALLOON_F_MUST_TELL_HOST feature is > +\change_inserted 1986246365 1347188540 > +negotiated > +\change_deleted 1986246365 1347188542 > +set > +\change_unchanged > +, the guest may not use these requested pages until that descriptor in the > + deflateq has been used by the device. > \end_layout > > \begin_layout Enumerate > -- > MST _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
