LXR linux/arch/arm64/kvm/hypercalls.c

   1// SPDX-License-Identifier: GPL-2.0
   2// Copyright (C) 2019 Arm Ltd.
   3
   4#include <linux/arm-smccc.h>
   5#include <linux/kvm_host.h>
   6
   7#include <asm/kvm_emulate.h>
   8
   9#include <kvm/arm_hypercalls.h>
  10#include <kvm/arm_psci.h>
  11
  12int kvm_hvc_call_handler(struct kvm_vcpu *vcpu)
  13{
  14        u32 func_id = smccc_get_function(vcpu);
  15        long val = SMCCC_RET_NOT_SUPPORTED;
  16        u32 feature;
  17        gpa_t gpa;
  18
  19        switch (func_id) {
  20        case ARM_SMCCC_VERSION_FUNC_ID:
  21                val = ARM_SMCCC_VERSION_1_1;
  22                break;
  23        case ARM_SMCCC_ARCH_FEATURES_FUNC_ID:
  24                feature = smccc_get_arg1(vcpu);
  25                switch (feature) {
  26                case ARM_SMCCC_ARCH_WORKAROUND_1:
  27                        switch (kvm_arm_harden_branch_predictor()) {
  28                        case KVM_BP_HARDEN_UNKNOWN:
  29                                break;
  30                        case KVM_BP_HARDEN_WA_NEEDED:
  31                                val = SMCCC_RET_SUCCESS;
  32                                break;
  33                        case KVM_BP_HARDEN_NOT_REQUIRED:
  34                                val = SMCCC_ARCH_WORKAROUND_RET_UNAFFECTED;
  35                                break;
  36                        }
  37                        break;
  38                case ARM_SMCCC_ARCH_WORKAROUND_2:
  39                        switch (kvm_arm_have_ssbd()) {
  40                        case KVM_SSBD_FORCE_DISABLE:
  41                        case KVM_SSBD_UNKNOWN:
  42                                break;
  43                        case KVM_SSBD_KERNEL:
  44                                val = SMCCC_RET_SUCCESS;
  45                                break;
  46                        case KVM_SSBD_FORCE_ENABLE:
  47                        case KVM_SSBD_MITIGATED:
  48                                val = SMCCC_RET_NOT_REQUIRED;
  49                                break;
  50                        }
  51                        break;
  52                case ARM_SMCCC_HV_PV_TIME_FEATURES:
  53                        val = SMCCC_RET_SUCCESS;
  54                        break;
  55                }
  56                break;
  57        case ARM_SMCCC_HV_PV_TIME_FEATURES:
  58                val = kvm_hypercall_pv_features(vcpu);
  59                break;
  60        case ARM_SMCCC_HV_PV_TIME_ST:
  61                gpa = kvm_init_stolen_time(vcpu);
  62                if (gpa != GPA_INVALID)
  63                        val = gpa;
  64                break;
  65        default:
  66                return kvm_psci_call(vcpu);
  67        }
  68
  69        smccc_set_retval(vcpu, val, 0, 0, 0);
  70        return 1;
  71}
  72