- mrs x1, esr_el2
- lsr x1, x1, #26
- cmp x1, #0x16
- b.ne 2f // Not an HVC trap
- cbz x0, 1f
- msr vbar_el2, x0 // Set vbar_el2
- b 2f
-1: mrs x0, vbar_el2 // Return vbar_el2
-2: eret
+ mrs x30, esr_el2
+ lsr x30, x30, #ESR_ELx_EC_SHIFT
+
+ cmp x30, #ESR_ELx_EC_HVC64
+ b.ne 9f // Not an HVC trap
+
+ cmp x0, #HVC_GET_VECTORS
+ b.ne 1f
+ mrs x0, vbar_el2
+ b 9f
+
+1: cmp x0, #HVC_SET_VECTORS
+ b.ne 2f
+ msr vbar_el2, x1
+ b 9f
+
+ /* Someone called kvm_call_hyp() against the hyp-stub... */
+2: mov x0, #ARM_EXCEPTION_HYP_GONE
+
+9: eret