On 26/01/16 14:04, Suzuki K. Poulose wrote:

On 25/01/16 15:53, Marc Zyngier wrote:

quoted

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.

quoted

  #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 ?

quoted

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

quoted

+
+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