arm64: KVM: Add EL1 async abort handler

If we've exited the guest because it has triggered an asynchronous
abort from EL1, a possible course of action is to let it know it
screwed up by giving it a Virtual Abort to chew on.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arch/arm64/kvm/handle_exit.c

@@ -173,6 +173,9 @@ int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
 	switch (exception_index) {
 	case ARM_EXCEPTION_IRQ:
 		return 1;
+	case ARM_EXCEPTION_EL1_SERROR:
+		kvm_inject_vabt(vcpu);
+		return 1;
 	case ARM_EXCEPTION_TRAP:
 		/*
 		 * See ARM ARM B1.14.1: "Hyp traps on instructions