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    SubjectRe: [PATCH v2 20/21] arm64: VHE: Add support for running Linux in EL2 mode
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    On 25/01/16 15:53, Marc Zyngier wrote:
    > With ARMv8.1 VHE, the architecture is able to (almost) transparently
    > run the kernel at EL2, despite being written for EL1.
    >
    > This patch takes care of the "almost" part, mostly preventing the kernel
    > from dropping from EL2 to EL1, and setting up the HYP configuration.

    > #ifdef CONFIG_COMPAT
    > @@ -521,6 +542,15 @@ CPU_LE( movk x0, #0x30d0, lsl #16 ) // Clear EE and E0E on LE systems
    > /* Stage-2 translation */
    > msr vttbr_el2, xzr
    >
    > + cbz x2, install_el2_stub

    Though it is apparent, may be its worth adding a comment here that we don't drop to EL1 here ?

    > +
    > + setup_vtcr x4, x5
    > +
    > + mov w20, #BOOT_CPU_MODE_EL2 // This CPU booted in EL2
    > + isb
    > + ret

    > +
    > +install_el2_stub:

    And a comment here mentioning, install the hyp stub and drops to EL1 ?

    > /* Hypervisor stub */
    > adrp x0, __hyp_stub_vectors
    > add x0, x0, #:lo12:__hyp_stub_vectors
    >

    Cheers
    Suzuki


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