On 11/09/2016 01:02 PM, Dave Young wrote: > On 11/09/16 at 11:58am, Wen Congyang wrote: >> On 11/09/2016 11:17 AM, Dave Young wrote: >>> 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. >> >> IIRC, 'virsh dump --memory-only' uses dump-guest-memory, and 'virsh dump' >> uses migration to dump. > > Do they need different fixes? Dave, I guess you mean --memory-only, but > could you clarify and confirm it? > >> >> I think I should study kaslr first... > > Thanks for taking care of it.
Can you give me the patch for kexec/kdump. I want to know what I need to do for dump-guest-memory. Thanks Wen Congyang > >> >> Thanks >> Wen Congyang >> >>>> >>>> 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 >>> >>> >>> >> >> >> > > > . >