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    SubjectRe: [PATCH] xen: core dom0 support

    * H. Peter Anvin <hpa@zytor.com> wrote:

    > Ingo Molnar wrote:
    > >
    > > Associativity effects do depend on the kernel image layout
    > > and on the precise allocations of kernel data structure
    > > allocations we do during bootup - and they dont really
    > > change after that.
    > >
    >
    > By the way, there is a really easy way (if a bit time
    > consuming) to get the actual variability here -- you have to
    > reboot between runs, even for the same kernel. It makes the
    > data collection take a long time, but at least it can be
    > scripted.

    Since it's the same kernel image i think the only truly reliable
    method would be to reboot between _different_ kernel images:
    same instructions but randomly re-align variables both in terms
    of absolute address and in terms of relative position to each
    other. Plus randomize bootmem allocs and never-gets-freed-really
    boot-time allocations.

    Really hard to do i think ...

    Ingo


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