__set_smccc_filter
r = __set_smccc_filter(vm, ARM_SMCCC_ARCH_WORKAROUND_1,
r = __set_smccc_filter(vm, smc64_fn, 1, KVM_SMCCC_FILTER_DENY);
r = __set_smccc_filter(vm, PSCI_0_2_FN64_CPU_ON, 0, KVM_SMCCC_FILTER_DENY);
r = __set_smccc_filter(vm, ~0, ~0, KVM_SMCCC_FILTER_DENY);
r = __set_smccc_filter(vm, PSCI_0_2_FN64_CPU_ON, 1, -1);
r = __set_smccc_filter(vm, PSCI_0_2_FN64_CPU_ON, 1, KVM_SMCCC_FILTER_DENY);
int ret = __set_smccc_filter(vm, start, nr_functions, action);