arm64: hyp-stub: Define a return value for failed stub calls

Define a standard return value to be returned when a hyp stub
call fails, and make KVM use it for ARM_EXCEPTION_HYP_GONE
(instead of using a KVM-specific value).

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index 49f99cd..b7e4ef5 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -28,7 +28,7 @@
 #define ARM_EXCEPTION_EL1_SERROR  1
 #define ARM_EXCEPTION_TRAP	  2
 /* The hyp-stub will return this for any kvm_call_hyp() call */
-#define ARM_EXCEPTION_HYP_GONE	  3
+#define ARM_EXCEPTION_HYP_GONE	  HVC_STUB_ERR
 
 #define KVM_ARM64_DEBUG_DIRTY_SHIFT	0
 #define KVM_ARM64_DEBUG_DIRTY		(1 << KVM_ARM64_DEBUG_DIRTY_SHIFT)