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    SubjectRe: [PATCH v3 23/23] arm64: Panic when VHE and non VHE CPUs coexist
    On Wed, Feb 03, 2016 at 06:00:16PM +0000, Marc Zyngier wrote:
    > Having both VHE and non-VHE capable CPUs in the same system
    > is likely to be a recipe for disaster.
    >
    > If the boot CPU has VHE, but a secondary is not, we won't be
    > able to downgrade and run the kernel at EL1. Add CPU hotplug
    > to the mix, and this produces a terrifying mess.
    >
    > Let's solve the problem once and for all. If you mix VHE and
    > non-VHE CPUs in the same system, you deserve to loose, and this
    > patch makes sure you don't get a chance.
    >
    > This is implemented by storing the kernel execution level in
    > a global variable. Secondaries will park themselves in a
    > WFI loop if they observe a mismatch. Also, the primary CPU
    > will detect that the secondary CPU has died on a mismatched
    > execution level. Panic will follow.
    >
    > Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

    Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>

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