[Qemu-devel] [PATCH 00/20] Reduce storage overhead of memory core

[Avi Kivity]

Currently the memory core requires 16 bytes per guest page (0.4% overhead).
This patchset, building on the patches posted last week, reduces the overhead
to practically nothing.  Assuming a 4k page size, contiguous aligned 4k, 4M,
and 4G regions each occupy just 2 bytes.  Since most guest memory is physically
contiguous, we can describe a guest with just a few dozen kilobytes.

Please review carefully, especially patch 13, and test carefully, especially
things like rom/device.

Also available in

  git://git.kernel.org/pub/scm/virt/kvm/qemu-kvm.git memory/core

Avi Kivity (20):
  memory: allow MemoryListeners to observe a specific address space
  xen: ignore I/O memory regions
  memory: split memory listener for the two address spaces
  memory: support stateless memory listeners
  memory: change memory registration to rebuild the memory map on each
    change
  memory: remove first level of l1_phys_map
  memory: unify phys_map last level with intermediate levels
  memory: store MemoryRegionSection pointers in phys_map
  memory: compress phys_map node pointers to 16 bits
  memory: fix RAM subpages in newly initialized pages
  memory: unify the two branches of cpu_register_physical_memory_log()
  memory: move tlb flush to MemoryListener commit callback
  memory: make phys_page_find() return a MemoryRegionSection
  memory: give phys_page_find() its own tree search loop
  memory: simplify multipage/subpage registration
  memory: replace phys_page_find_alloc() with phys_page_set()
  memory: switch phys_page_set() to a recursive implementation
  memory: change phys_page_set() to set multiple pages
  memory: unify PhysPageEntry::node and ::leaf
  memory: allow phys_map tree paths to terminate early

 exec.c     |  828 +++++++++++++++++++++++++++++++++++++----------------------
 hw/vhost.c |   18 ++-
 kvm-all.c  |   18 ++-
 memory.c   |   50 ++++-
 memory.h   |    7 +-
 xen-all.c  |   18 ++-
 6 files changed, 620 insertions(+), 319 deletions(-)

-- 
1.7.9