Re: [Qemu-devel] [PATCH v4 0/9] Make 'dump-guest-memory' dump in kdump-compressed format

[Qiao Nuohan]

> I haven't reviewed it yet, but we need introspection support before merging
> this.

Hello Luiz,

Is it possible to get this reviewed, or I am supposed to wait until
introspection support being settled?

On 05/28/2013 10:50 AM, address@hidden wrote:
> From: Qiao Nuohan<address@hidden>
>
> Hi, all
>
> The last version is here:
> http://lists.gnu.org/archive/html/qemu-devel/2013-05/msg02280.html
>
> Command 'dump-guest-memory' was introduced to dump guest's memory. But the
> vmcore's format is only elf32 or elf64. The message is here:
> http://lists.gnu.org/archive/html/qemu-devel/2012-04/msg03379.html
>
> For migration, 'dump-guest-memory' is supposed to support compression feature.
> Because of the regression, the missing of compression feature, we post these
> patches to make 'dump-guest-memory' be able to dump guest's in kdump-compressed
> format. Then vmcore can be much smaller, and easily be delivered.
>
> The kdump-compressed format is *linux specific* *linux standard* crash dump
> format used in kdump framework. The kdump-compressed format is readable only
> with the crash utility, and it can be smaller than the ELF format because of
> the compression support.
>
> Note, similar to 'dump-guest-memory':
> 1. The guest should be x86 or x86_64. The other arch is not supported now.
> 2. If the OS is in the second kernel, gdb may not work well, and crash can
>     work by specifying '--machdep phys_addr=xxx' in the command line. The
>     reason is that the second kernel will update the page table, and we can
>     not get the page table for the first kernel.
> 3. The cpu's state is stored in QEMU note.
> 4. The vmcore are able to be compressed with zlib, lzo or snappy. zlib is
>     available by default, and option '--enable-lzo' or '--enable-snappy'
>     should be used with configure to make lzo or snappy available.
>
> Changelog:
> Changes from v3 to v4:
> 1. change to avoid conflict with Andreas's patches
> 2. rebase
>
> Changes from v2 to v3:
> 1. Address Eric's comment
>
> Changes from v1 to v2:
> 1. Address Eric&  Daniel's comment: fix manner of string copy.
> 2. Address Eric's comment: replace reinventing new constants by using the
>     ready-made ones accoring.
> 3. Address Andreas's comment: remove useless include.
>
>
> Qiao Nuohan (9):
>    dump: Add API to manipulate dump_bitmap
>    dump: Add API to manipulate cache_data
>    dump: Move struct definition into dump_memroy.h
>    dump: Add API to create header of vmcore
>    dump: Add API to create data of dump bitmap
>    dump: Add API to create page
>    dump: Add API to free memory used by creating header, bitmap and page
>    dump: Add API to write header, bitmap and page into vmcore
>    dump: Make kdump-compressed format available for 'dump-guest-memory'
>
>   Makefile.target              |    1 +
>   cache_data.c                 |  121 ++++++
>   configure                    |   50 +++
>   dump.c                       |  866 ++++++++++++++++++++++++++++++++++++++++--
>   dump_bitmap.c                |  171 +++++++++
>   hmp-commands.hx              |   12 +-
>   hmp.c                        |   23 +-
>   include/cache_data.h         |   56 +++
>   include/dump_bitmap.h        |   60 +++
>   include/sysemu/dump_memory.h |  178 +++++++++
>   qapi-schema.json             |   22 +-
>   qmp-commands.hx              |    6 +-
>   12 files changed, 1526 insertions(+), 40 deletions(-)
>   create mode 100644 cache_data.c
>   create mode 100644 dump_bitmap.c
>   create mode 100644 include/cache_data.h
>   create mode 100644 include/dump_bitmap.h
>   create mode 100644 include/sysemu/dump_memory.h


--
Regards
Qiao Nuohan