virt/kvm/arm/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
  12 int 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_RET_NOT_REQUIRED;
  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 }