[PATCH v2 20/21] arm64: VHE: Add support for running Linux in EL2 mode
Suzuki K. Poulose
Suzuki.Poulose at arm.com
Tue Jan 26 06:30:13 PST 2016
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
> 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.
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