[Qemu-devel] virsh dump (qemu guest memory dump?): KASLR enabled linux guest support

[Dave Young]

Hi,

Latest linux kernel enabled kaslr to randomiz phys/virt memory
addresses, we had some effort to support kexec/kdump so that crash
utility can still works in case crashed kernel has kaslr enabled.

But according to Dave Anderson virsh dump does not work, quoted messages
from Dave below:

"""
with virsh dump, there's no way of even knowing that KASLR
has randomized the kernel __START_KERNEL_map region, because there is no
virtual address information -- e.g., like "SYMBOL(_stext)" in the kdump
vmcoreinfo data to compare against the vmlinux file symbol value.
Unless virsh dump can export some basic virtual memory data, which
they say it can't, I don't see how KASLR can ever be supported.
"""

I assume virsh dump is using qemu guest memory dump facility so it
should be first addressed in qemu. Thus post this query to qemu devel
list. If this is not correct please let me know.

Could you qemu dump people make it work? Or we can not support virt dump
as long as KASLR being enabled. Latest Fedora kernel has enabled it in x86_64.

Thanks
Dave