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

[Dave Young]

Drop qiaonuohan, seems the mail address is wrong..

On 11/09/16 at 11:01am, Dave Young wrote:
> 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