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

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(a)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(a)redhat.com&gt; > 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@0 > > By prepending the ramdump image name with "live:", the crash session > will > act as if it were running a normal live session. > (oleg(a)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(a)redhat.com&gt; > 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(a)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(a)redhat.com > https://www.redhat.com/mailman/listinfo/crash-utility > -- Crash-utility mailing list Crash-utility(a)redhat.com https://www.redhat.com/mailman/listinfo/crash-utility