| Subject | Re: [PATCH v2 20/21] arm64: VHE: Add support for running Linux in EL2 mode | From | "Suzuki K. Poulose" <> | Date | Tue, 26 Jan 2016 14:30:13 +0000 |
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On 26/01/16 14:04, Suzuki K. Poulose wrote: > 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 ?
Also, the comments around el2_setup invocation still says, Drop to EL1 which may need to be updated.
Cheers Suzuki
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