[Crash-utility] [PATCH 0/2] qemu: Parse necessary sections in crash added in qemu

[Pankaj Gupta]

Thanks Dave.

Best regards,
Pankaj
> 
> 
> Hi Pankaj,
> 
> Queued for crash-7.1.6:
> 
>   https://github.com/crash-utility/crash/commit/8cb8e85de65c4b51ca7537186e60dd560a4ed9db
> 
> Dave
> 
> 
> ----- Original Message -----
> > 
> > BTW, this footerSecId variable should be declared as ATTRIBUTE_UNUSED:
> > 
> > $ make warn
> > ... [ cut ] ...
> > cc -c -g -DX86_64 -DLZO -DSNAPPY -DGDB_7_6  qemu-load.c -Wall -O2
> > -Wstrict-prototypes -Wmissing-prototypes -fstack-protector
> > -Wformat-security
> > qemu-load.c: In function 'qemu_load':
> > qemu-load.c:976:13: warning: unused variable 'footerSecId'
> > [-Wunused-variable]
> >     uint32_t footerSecId = get_be32 (fp);
> > ...
> > 
> > Dave
> > 
> > 
> > ----- Original Message -----
> > > 
> > > 
> > > ----- Original Message -----
> > > > Qemu migration code added new sections to add features
> > > > for live migration of VM. For loading vmcore file captured
> > > > with 'virsh dump' we need to parse these sections in crash.
> > > > 
> > > > This series contains two patches, which parse these sections:
> > > > 
> > > > patch1: parse 'vm_configuration' section
> > > > patch2: parse 'vm_footer' section
> > > > 
> > > >  qemu-load.c |   20 ++++++++++++++++++++
> > > >  qemu-load.h |    4 +++-
> > > >  2 files changed, 23 insertions(+), 1 deletion(-)
> > > > 
> > > > --
> > > > Crash-utility mailing list
> > > > Crash-utility at redhat.com
> > > > https://www.redhat.com/mailman/listinfo/crash-utility
> > > > 
> > > 
> > > Hi Pankaj,
> > > 
> > > I suppose I can take the patch.  But, given the advent of "virsh dump
> > > --memory-only"
> > > back in 2012, and more recently, Oleg's added support for QEMU ramdumps
> > > by specifying
> > > a memory-backend-file object to the qemu-kvm command:
> > > 
> > >   commit 89ed9d0a7f7da4578294a492c1ad857244ce7352
> > >   Author: Dave Anderson <anderson at redhat.com>
> > >   Date:   Wed May 4 11:50:19 2016 -0400
> > > 
> > >     Introduction of support for "live" ramdump files, such as those that
> > >     are specified by the QEMU mem-path argument of a memory-backend-file
> > >     object.  This allows the running of a live crash session against a
> > >     QEMU guest from the host machine.  In this example, the /tmp/MEM file
> > >     on a QEMU host represents the guest's physical memory:
> > >     
> > >       $ qemu-kvm ...other-options... \
> > >       -object
> > >       memory-backend-file,id=MEM,size=128m,mem-path=/tmp/MEM,share=on
> > >       \
> > >       -numa node,memdev=MEM -m 128
> > >     
> > >     and a live session run can be run against the guest kernel like so:
> > >     
> > >       $ crash <path-to-guest-vmlinux> live:/tmp/MEM at 0
> > >     
> > >     By prepending the ramdump image name with "live:", the crash session
> > >     will
> > >     act as if it were running a normal live session.
> > >     (oleg at redhat.com)
> > > 
> > > And if the guest above crashed, the leftover file can be used as a
> > > regular
> > > ramdump dumpfile:
> > > 
> > >   commit 67a815b8749fbd5c99c29d24b4e699b1d618ddbf
> > >   Author: Dave Anderson <anderson at redhat.com>
> > >   Date:   Wed May 4 14:34:53 2016 -0400
> > > 
> > >     Added support for x86_64 ramdump files.  Without the patch, the crash
> > >     session fails immediately with the message "ramdump: unsupported
> > >     machine type: X86_64".
> > >     (anderson at redhat.com)
> > > 
> > > 
> > > So I don't know why anybody would ever want to use the old "kvmdump"
> > > format?
> > > It's for all practical purposes deprecated, not to mention that it's
> > > really
> > > an unsuitable excuse for a crash dumpfile.
> > > 
> > > Dave
> > > 
> > > --
> > > Crash-utility mailing list
> > > Crash-utility at redhat.com
> > > https://www.redhat.com/mailman/listinfo/crash-utility
> > > 
> > 
> > --
> > Crash-utility mailing list
> > Crash-utility at redhat.com
> > https://www.redhat.com/mailman/listinfo/crash-utility
> > 
> 
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