Ok, I can see how this will work better for the migration case. Acked-by: Adam Litke <a...@us.ibm.com>
On Tue, 2010-09-14 at 11:09 -0300, Eduardo Habkost wrote: > This field is guest-visible, won't this cause problems on migration? > > Isn't it better to disable it on the "info balloon" side, so the guest > knows that the host may start requesting stat info eventually? I suggest > doing this: > > --- > diff --git a/hw/virtio-balloon.c b/hw/virtio-balloon.c > index 1e4dfdd..92e9057 100644 > --- a/hw/virtio-balloon.c > +++ b/hw/virtio-balloon.c > @@ -30,6 +30,10 @@ > #include <sys/mman.h> > #endif > > +/* Disable guest-provided stats by now (bz#623903, bz#626544) */ > +#define ENABLE_GUEST_STATS 0 > + > + > typedef struct VirtIOBalloon > { > VirtIODevice vdev; > @@ -84,12 +88,14 @@ static QObject *get_stats_qobject(VirtIOBalloon *dev) > VIRTIO_BALLOON_PFN_SHIFT); > > stat_put(dict, "actual", actual); > +#if ENABLE_GUEST_STATS > stat_put(dict, "mem_swapped_in", dev->stats[VIRTIO_BALLOON_S_SWAP_IN]); > stat_put(dict, "mem_swapped_out", dev->stats[VIRTIO_BALLOON_S_SWAP_OUT]); > stat_put(dict, "major_page_faults", dev->stats[VIRTIO_BALLOON_S_MAJFLT]); > stat_put(dict, "minor_page_faults", dev->stats[VIRTIO_BALLOON_S_MINFLT]); > stat_put(dict, "free_mem", dev->stats[VIRTIO_BALLOON_S_MEMFREE]); > stat_put(dict, "total_mem", dev->stats[VIRTIO_BALLOON_S_MEMTOT]); > +#endif > > return QOBJECT(dict); > } > @@ -215,7 +221,7 @@ static void virtio_balloon_to_target(void *opaque, > ram_addr_t target, > } > dev->stats_callback = cb; > dev->stats_opaque_callback_data = cb_data; > - if (dev->vdev.guest_features & (1 << VIRTIO_BALLOON_F_STATS_VQ)) { > + if (ENABLE_GUEST_STATS && (dev->vdev.guest_features & (1 << > VIRTIO_BALLOON_F_STATS_VQ))) { > virtqueue_push(dev->svq, &dev->stats_vq_elem, > dev->stats_vq_offset); > virtio_notify(&dev->vdev, dev->svq); > } else { > -- Thanks, Adam