KVM: arm64: selftests: Enable EL2 by default

Take advantage of VHE to implicitly promote KVM selftests to run at EL2
with only slight modification. Update the smccc_filter test to account
for this now that the EL2-ness of a VM is visible to tests.

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>

Author: oupton

tools/testing/selftests/kvm/arm64/smccc_filter.c

@@ -22,8 +22,20 @@ enum smccc_conduit {
 	SMC_INSN,
 };
 
+static bool test_runs_at_el2(void)
+{
+	struct kvm_vm *vm = vm_create(1);
+	struct kvm_vcpu_init init;
+
+	kvm_get_default_vcpu_target(vm, &init);
+	kvm_vm_free(vm);
+
+	return init.features[0] & BIT(KVM_ARM_VCPU_HAS_EL2);
+}
+
 #define for_each_conduit(conduit)					\
-	for (conduit = HVC_INSN; conduit <= SMC_INSN; conduit++)
+	for (conduit = test_runs_at_el2() ? SMC_INSN : HVC_INSN;	\
+	     conduit <= SMC_INSN; conduit++)
 
 static void guest_main(uint32_t func_id, enum smccc_conduit conduit)
 {

tools/testing/selftests/kvm/include/arm64/processor.h

@@ -303,6 +303,7 @@ void wfi(void);
 void test_wants_mte(void);
 void test_disable_default_vgic(void);
 
+bool vm_supports_el2(struct kvm_vm *vm);
 static bool vcpu_has_el2(struct kvm_vcpu *vcpu)
 {
 	return vcpu->init.features[0] & BIT(KVM_ARM_VCPU_HAS_EL2);

tools/testing/selftests/kvm/lib/arm64/processor.c

@@ -267,11 +267,23 @@ void virt_arch_dump(FILE *stream, struct kvm_vm *vm, uint8_t indent)
 	}
 }
 
+bool vm_supports_el2(struct kvm_vm *vm)
+{
+	const char *value = getenv("NV");
+
+	if (value && *value == '0')
+		return false;
+
+	return vm_check_cap(vm, KVM_CAP_ARM_EL2) && vm->arch.has_gic;
+}
+
 void kvm_get_default_vcpu_target(struct kvm_vm *vm, struct kvm_vcpu_init *init)
 {
 	struct kvm_vcpu_init preferred = {};
 
 	vm_ioctl(vm, KVM_ARM_PREFERRED_TARGET, &preferred);
+	if (vm_supports_el2(vm))
+		preferred.features[0] |= BIT(KVM_ARM_VCPU_HAS_EL2);
 
 	*init = preferred;
 }