"Michael S. Tsirkin" <mst@xxxxxxxxxx> writes: > 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, I just s/set/negotiated: --- virtio-spec.txt.old 2013-06-17 16:03:51.875066122 +0930 +++ virtio-spec.txt 2013-06-17 16:07:42.291063924 +0930 @@ -2411,9 +2411,9 @@ it has previously given to the balloon, as described above. This descriptor is added to the deflateq. - (b) 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. + (b) If the VIRTIO_BALLOON_F_MUST_TELL_HOST feature is + negotiated, the guest may not use these requested pages until + that descriptor in the deflateq has been used by the device. (c) Otherwise, the guest may begin to re-use pages previously given to the balloon before the device has acknowledged their I'm think we get rid of the output queue for balloon in future. Cheers, Rusty. _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization