Re: [Qemu-devel] [PATCH v8 00/13] Make 'dump-guest-memory' dump in kdump-compressed format

[Qiao Nuohan <qiaonuohan@cn.fujitsu.com>]

On 02/18/2014 01:51 AM, Luiz Capitulino wrote:
> On Tue, 11 Feb 2014 12:00:56 -0500
> Luiz Capitulino<lcapitulino@redhat.com>  wrote:
>
>> On Tue, 28 Jan 2014 14:21:53 +0800
>> qiaonuohan<qiaonuohan@cn.fujitsu.com>  wrote:
>>
>>> Hi, all
>>>
>>> The last version is here:
>>> http://lists.nongnu.org/archive/html/qemu-devel/2014-01/msg00209.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
>>>
>>> Compared with migration, the missing of compression feature means regression
>>> to 'dump-guest-memory'. So 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 to 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. To get more detailed information about
>>> kdump-compressed format, please refer to the following URL:
>>> http://sourceforge.net/projects/makedumpfile/
>>
>> I did what was requested by Paolo. I applied patches 1 to 12 and will wait
>> for the rework on patch 13.
>
> Unfortunately this series doesn't build on 32-bit hosts, so I had to drop it
> from my queue (see error below). Can you please do the following:
>
> 1. Fix the build
> 2. Add new patch 13/13 to the series
> 3. Add Ekaterina's patch to your series
>
> Thanks. Here's the error message:
>
> ar: creating libfdt/libfdt.a
> /root/qmp-unstable/dump.c: In function ‘write_dump_pages’:
> /root/qmp-unstable/dump.c:1356:21: error: passing argument 2 of ‘compress2’ from incompatible pointer type [-Werror]
>                       Z_BEST_SPEED) == Z_OK)&&  (size_out<  s->page_size)) {
>                       ^
> In file included from /root/qmp-unstable/dump.c:28:0:
> /usr/include/zlib.h:1174:21: note: expected ‘uLongf *’ but argument is of type ‘size_t *’
>   ZEXTERN int ZEXPORT compress2 OF((Bytef *dest,   uLongf *destLen,
>                       ^
> cc1: all warnings being treated as errors
> make[1]: *** [dump.o] Error 1
> make: *** [subdir-aarch64-softmmu] Error 2
> make: *** Waiting for unfinished jobs....
> /root/qmp-unstable/dump.c: In function ‘write_dump_pages’:
> /root/qmp-unstable/dump.c:1356:21: error: passing argument 2 of ‘compress2’ from incompatible pointer type [-Werror]
>                       Z_BEST_SPEED) == Z_OK)&&  (size_out<  s->page_size)) {
>                       ^
> In file included from /root/qmp-unstable/dump.c:28:0:
> /usr/include/zlib.h:1174:21: note: expected ‘uLongf *’ but argument is of type ‘size_t *’
>   ZEXTERN int ZEXPORT compress2 OF((Bytef *dest,   uLongf *destLen,
>                       ^
> cc1: all warnings being treated as errors
> make[1]: *** [dump.o] Error 1
> make[1]: *** Waiting for unfinished jobs....
> make: *** [subdir-alpha-softmmu] Error 2
>
>

Hello Luiz,

It seems both zlib and lzo will output the error message because of the
incompatible type. And I have fixed patches and sent them to the qemu list.

P.S.
lzo/snappy will need '--enable-lzo' or '--enable-snappy' at configure.

-- 
Regards
Qiao Nuohan