[Qemu-devel] [PATCH v10 0/3] Add bitmap for received pages in postcopy migration

[Alexey Perevalov]

This is 10th version of
[PATCH v1 0/2] Add bitmap for copied pages in postcopy migration
cover message from there

This is a separate patch set, it derived from
https://www.mail-archive.com/address@hidden/msg456004.html

There are several possible use cases:
1. solve issue with postcopy live migration and shared memory.
OVS-VSWITCH requires information about copied pages, to fallocate
newly allocated pages.
2. calculation vCPU blocktime
for more details see
https://www.mail-archive.com/address@hidden/msg456004.html
3. Recovery after fail in the middle of postcopy migration 

----------------------------------------------------------------
V10 -> V9
    - ramblock_recv_bitmap_clear was removed from patchset, due to
I didn't find any usage of it in existing patchsets based on this patch.

V8 -> V9
    - patch: "migration: fix incorrect postcopy recved_bitmap" from
"[RFC 00/29] Migration: postcopy failure recovery" patch set was squashed
into the latest patch of this patchset, getpagesize was replaced to
qemu_target_page_size, as David suggested.
    - for the sake of API uniformity semantics of all functions were
changed, now RAMBlock *rb is the first argument, as well as in bitmap API.
    - Also define TARGET_PAGE_BITS was replaced to qemu_target_page_bits in
all other places of this patchset, for uniformity and maintenance. 

V7 -> V8
    - removed unnecessary renaming and moving of block variable to ram_load's
function scope
    - ramblock_recv_map_init became static function

V6 -> V7
    - rebased on
[PATCH v7 0/5] Create setup/cleanup methods for migration incoming side
    - live time of the received map was changed 
(ram_load_setup/ram_load_cleanup) 

V5 -> V6
    - call ramblock_recv_map_init from migration_fd_process_incoming (Peter 
suggested)But finalization is still in ram_load_cleanup as Juan suggested.    

V4 -> V5
    - remove ramblock_recv_bitmap_clear_range in favor to bitmap_clear (comment 
from David)
    - single invocation place for ramblock_recv_bitmap_set (comment from Peter)
    - minor changes like removing comment from qemu_ufd_copy_ioctl and local 
variable from
ramblock_recv_map_init (comment from Peter)

V3 -> V4
    - clear_bit instead of ramblock_recv_bitmap_clear in 
ramblock_recv_bitmap_clear_range,
it reduced number of operation (comment from Juan)
    - for postcopy ramblock_recv_bitmap_set is calling after page was copied,
only in case of success (comment from David)
    - indentation fixes (comment from Juan)

V2 -> V3
    - ramblock_recv_map_init call is placed into migration_incoming_get_current,
looks like it's general place for both precopy and postcopy case.
    - received bitmap memory releasing is placed into ram_load_cleanup,
unfortunatelly, it calls only in case of precopy.
    - precopy case and discard ram block case
    - function renaming, and another minor cleanups

V1 -> V2
    - change in terminology s/copied/received/g
    - granularity became TARGET_PAGE_SIZE, but not actual page size of the
ramblock
    - movecopiedmap & get_copiedmap_size were removed, until patch set where
it will be necessary
    - releasing memory of receivedmap was added into ram_load_cleanup
    - new patch "migration: introduce qemu_ufd_copy_ioctl helper"

Patchset is based on:
commit d147f7e815f97cb477e223586bcb80c316ae10ea
Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into staging

Alexey Perevalov (3):
  migration: postcopy_place_page factoring out
  migration: introduce qemu_ufd_copy_ioctl helper
  migration: add bitmap for received page

 include/exec/ram_addr.h  | 10 +++++++++
 migration/postcopy-ram.c | 54 +++++++++++++++++++++++++++++++-----------------
 migration/postcopy-ram.h |  4 ++--
 migration/ram.c          | 44 +++++++++++++++++++++++++++++++++++++--
 migration/ram.h          |  5 +++++
 5 files changed, 94 insertions(+), 23 deletions(-)

-- 
2.7.4