[libvirt-users] Understanding the contents of virsh dump --memory-only

[Arnabjyoti Kalita]

Hello,

I was trying to understand the ELF file generated by the virsh dump
(--memory-only) command. I have successfully generated a dump of the VM
memory using this command.

I specifically am trying to understand the loadable segments of this ELF
file.

I ran readelf -a <filename> to get the information that I need. Below shows
the details of the loadable segments in a much better format :-

Loading ELF header #1. offset: 1320 filesize: 655360 memsize: 655360 vaddr:
0 paddr: 0 align: 0 flags: 0
Loading ELF header #2. offset: 656680 filesize: 65536 memsize: 65536 vaddr:
0 paddr: a0000 align: 0 flags: 0
Loading ELF header #3. offset: 722216 filesize: 1072955392 memsize:
1072955392 vaddr: 0 paddr: c0000 align: 0 flags: 0
Loading ELF header #4. offset: 1073677608 filesize: 67108864 memsize:
67108864 vaddr: 0 paddr: f4000000 align: 0 flags: 0
Loading ELF header #5. offset: 1140786472 filesize: 67108864 memsize:
67108864 vaddr: 0 paddr: f8000000 align: 0 flags: 0
Loading ELF header #6. offset: 1207895336 filesize: 8192 memsize: 8192
vaddr: 0 paddr: fc054000 align: 0 flags: 0
Loading ELF header #7. offset: 1207903528 filesize: 262144 memsize: 262144
vaddr: 0 paddr: fffc0000 align: 0 flags: 0

I wanted to know why in this case, is the virtual address (denoted by
vaddr) 0 for each of the loadable segments ? Will it be okay if I load the
elf file taking the values of physical address (denoted by paddr) into
account ?

Specifically after loading the file, can I be certain that all of my
contents will have been loaded into memory address starting from 0 ? Will
the loaded contents be present in the exact location as specified (by
paddr) here ?

Thanks and Regards.
Arnab
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