On Thu, 27 Nov 2014 17:34:19 +0200 "Michael S. Tsirkin" <mst@xxxxxxxxxx> wrote: > On Thu, Nov 27, 2014 at 04:16:36PM +0100, Cornelia Huck wrote: > > With virtio-1, we support more than 32 feature bits. Let's make > > vdev->guest_features depend on the number of supported feature bits, > > allowing us to grow the feature bits automatically. ^ This was one reason why I did it this way... > > > > We also need to enhance the internal functions dealing with getting > > and setting features with an additional index field, so that all feature > > bits may be accessed (in chunks of 32 bits). > > > > vhost and migration have been ignored for now. > > > > Reviewed-by: Thomas Huth <thuth@xxxxxxxxxxxxxxxxxx> > > Signed-off-by: Cornelia Huck <cornelia.huck@xxxxxxxxxx> > > @@ -117,7 +125,7 @@ struct VirtIODevice > > uint8_t status; > > uint8_t isr; > > uint16_t queue_sel; > > - uint32_t guest_features; > > + uint32_t guest_features[NR_VIRTIO_FEATURE_WORDS]; > > size_t config_len; > > void *config; > > uint16_t config_vector; > > Ugh. > > That's quite tricky to use correctly. > Why don't we just make it uint64_t? ...and another one was that at least virtio-ccw reads/writes in chunks of 32 bits anyway. > > The only real issue is that DEFINE_PROP_BIT wants > a uint32_t. > > But that's easy to fix: add DEFINE_PROP64_BIT > that is the same but handles a 64 bit array. > Sure, this would not really be a problem to add. But we'll stand before the same problem again when we want to grow past 64 bits, won't we? _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
