As we discovered yet another issue with current PBP code, we decided
to use a temporary PBP only, limited to one series of inflation requests.

Patch #1 is a fix for a wrong sign extension (MST brought this up but
wasn't sure if it is broken - I think it is indeed broken). Patch #2 fixed
QEMU segfaults. Patch #3 and #4 are cleanups that make follow-up fixes
easier. Patch #5 avoids using RAMBlock addresses as tokens and patch #6
fixes all kinds of issues related to using a global PBP. Patch #7 gets
rid of a temporary workaround from patch #5.

We want to have patches 1-6 in 4.1 and backport them to 4.0. Patch #1
needs backports to basically all QEMU releases with virtio-balloon.

Did a quick sanity test, hopefully no other BUG sneeked in. Will do some
more testing.

v3 -> v4:
- Add "virtio-balloon: No need to track subpages for the PBP anymore",
  which doesn't need a stable backport

Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: qemu-stable@nongnu.org

David Hildenbrand (7):
  virtio-balloon: Fix wrong sign extension of PFNs
  virtio-balloon: Fix QEMU crashes on pagesize > BALLOON_PAGE_SIZE
  virtio-balloon: Simplify deflate with pbp
  virtio-balloon: Better names for offset variables in inflate/deflate
    code
  virtio-balloon: Rework pbp tracking data
  virtio-balloon: Use temporary PBP only
  virtio-balloon: No need to track subpages for the PBP anymore

 hw/virtio/virtio-balloon.c         | 120 ++++++++++++++---------------
 include/hw/virtio/virtio-balloon.h |   3 -
 2 files changed, 60 insertions(+), 63 deletions(-)

-- 
2.21.0