Obtain dirty bitmap via VM logging

Hi,

This is the first part of my gsoc work.

Following patches add the support of dirty bitmap logging and dumping to a specified file. These patches provide the mechanism to get the dirty bitmap if the user wants to log the VM besides migration. This can be useful in case of learning about the writable working set of the VM even when it is not being migrated. I know that it will incur huge degradation but still, a user might want to do that. Besides this, this mechanism can also be useful in case of learning about the pages that can be stored in the cache while performing the xbzrle based live migration or even before the beginning of the hybrid (precopy + postcopy) live migration.

I have tried to provide both of the hmp and qmp commands interface to obtain the dirty bitmap. Besides dumping the dirty bitmap, one can also update the frequency with which the logging is taking place or even can cancel the ongoing logging process. Thus, there are 3 hmp and qmp commands interface provided to perform the task.

Sanidhya Kashyap (6):
split dirty bitmap into four for dumping the bitmaps bitmap dump code via QAPI framework
hmp interface for dirty bitmap dump
cancel mechanism for an already running dump bitmap process set the frequency of the dump bitmap process python script for extracting bitmap from a binary file

 exec.c                    |   4 +
 hmp-commands.hx           |  46 +++++++
 hmp.c                     |  36 +++++
 hmp.h                     |   3 +
 include/exec/memory.h     |   3 +-
 include/exec/ram_addr.h   |  16 ++-
 include/qapi/qmp/qerror.h |   3 +
 qapi-schema.json          |  23 ++++
 qmp-commands.hx           |  77 +++++++++++
 savevm.c                  | 344 ++++++++++++++++++++++++++++++++++++++++++++++
 scripts/extract-bitmap.py |  68 +++++++++
 11 files changed, 621 insertions(+), 2 deletions(-)
 create mode 100755 scripts/extract-bitmap.py

1.8.3.1