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    SubjectRe: [RFC PATCH] x86/msr: Filter MSR writes
    On Fri, Jun 12, 2020 at 09:57:09AM -0700, Sean Christopherson wrote:
    > DS_AREA takes a virtual (linear) address, i.e. the address can be legal from
    > the CPUs perspective but still lead to a #PF due to the address not being
    > mapped in the page tables.

    It's not that - peterz and tglx - and I assume you meant that too - you
    all want to taint on the very *attempt* to WRMSR, regardless of whether
    the MSR exists or not.

    I don't necessarily agree with that because I don't think we should
    taint when the MSR doesn't exist but if you all want it, sure, whatever.
    I don't care that deeply.

    > So users don't have to unload and reload the module just to enable or
    > disable writes. I don't think it changes the protections in any way, a
    > priveleged user still needs to explicitly toggle the control.

    There's /sys/module/msr/parameters/. A privileged user can do whatever.
    A non-privileged should not disable that.

    --
    Regards/Gruss,
    Boris.

    https://people.kernel.org/tglx/notes-about-netiquette

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