Rework vhost memory region updates

From: "Dr. David Alan Gilbert" <[email protected]>

Hi,
This patch set reworks the way the vhost code handles changes in
physical address space layout that came from a discussion with Igor.

Its intention is to simplify a lot of the update code, and to make it easier for the postcopy+shared code to do the hugepage alignments that are needed.

Instead of inserting/removing each section during the add/del callbacks of the listener, we start afresh and build a list from the add and nop callbacks, then at the end compare the list we've built with the exisiting list.

v7
Avoid calling memcmp(NULL,NULL,0) in region list compare

v6
Tidy ups from Igor
The biggest change is moving the 'Move log_dirty check' to be the last patch in the set.

Dr. David Alan Gilbert (7):
vhost: Build temporary section list and deref after commit
vhost: Simplify ring verification checks
vhost: Merge sections added to temporary list
vhost: Regenerate region list from changed sections list
vhost: Clean out old vhost_set_memory and friends
vhost: Merge and delete unused callbacks
vhost: Move log_dirty check

 hw/virtio/trace-events    |   6 +
 hw/virtio/vhost.c         | 497 ++++++++++++++++------------------------------
 include/hw/virtio/vhost.h |   5 +-
 3 files changed, 180 insertions(+), 328 deletions(-)

2.14.3