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 #include <linux/sched/stat.h> 7 8 #include <asm/kvm_mmu.h> 9 #include <asm/pvclock-abi.h> 10 11 #include <kvm/arm_hypercalls.h> 12 13 void kvm_update_stolen_time(struct kvm_vcpu *vcpu) 14 { 15 struct kvm *kvm = vcpu->kvm; 16 u64 base = vcpu->arch.steal.base; 17 u64 last_steal = vcpu->arch.steal.last_steal; 18 u64 offset = offsetof(struct pvclock_vcpu_stolen_time, stolen_time); 19 u64 steal = 0; 20 int idx; 21 22 if (base == GPA_INVALID) 23 return; 24 25 idx = srcu_read_lock(&kvm->srcu); 26 if (!kvm_get_guest(kvm, base + offset, steal)) { 27 steal = le64_to_cpu(steal); 28 vcpu->arch.steal.last_steal = READ_ONCE(current->sched_info.run_delay); 29 steal += vcpu->arch.steal.last_steal - last_steal; 30 kvm_put_guest(kvm, base + offset, cpu_to_le64(steal)); 31 } 32 srcu_read_unlock(&kvm->srcu, idx); 33 } 34 35 long kvm_hypercall_pv_features(struct kvm_vcpu *vcpu) 36 { 37 u32 feature = smccc_get_arg1(vcpu); 38 long val = SMCCC_RET_NOT_SUPPORTED; 39 40 switch (feature) { 41 case ARM_SMCCC_HV_PV_TIME_FEATURES: 42 case ARM_SMCCC_HV_PV_TIME_ST: 43 if (vcpu->arch.steal.base != GPA_INVALID) 44 val = SMCCC_RET_SUCCESS; 45 break; 46 } 47 48 return val; 49 } 50 51 gpa_t kvm_init_stolen_time(struct kvm_vcpu *vcpu) 52 { 53 struct pvclock_vcpu_stolen_time init_values = {}; 54 struct kvm *kvm = vcpu->kvm; 55 u64 base = vcpu->arch.steal.base; 56 int idx; 57 58 if (base == GPA_INVALID) 59 return base; 60 61 /* 62 * Start counting stolen time from the time the guest requests 63 * the feature enabled. 64 */ 65 vcpu->arch.steal.last_steal = current->sched_info.run_delay; 66 67 idx = srcu_read_lock(&kvm->srcu); 68 kvm_write_guest(kvm, base, &init_values, sizeof(init_values)); 69 srcu_read_unlock(&kvm->srcu, idx); 70 71 return base; 72 } 73 74 bool kvm_arm_pvtime_supported(void) 75 { 76 return !!sched_info_on(); 77 } 78 79 int kvm_arm_pvtime_set_attr(struct kvm_vcpu *vcpu, 80 struct kvm_device_attr *attr) 81 { 82 u64 __user *user = (u64 __user *)attr->addr; 83 struct kvm *kvm = vcpu->kvm; 84 u64 ipa; 85 int ret = 0; 86 int idx; 87 88 if (!kvm_arm_pvtime_supported() || 89 attr->attr != KVM_ARM_VCPU_PVTIME_IPA) 90 return -ENXIO; 91 92 if (get_user(ipa, user)) 93 return -EFAULT; 94 if (!IS_ALIGNED(ipa, 64)) 95 return -EINVAL; 96 if (vcpu->arch.steal.base != GPA_INVALID) 97 return -EEXIST; 98 99 /* Check the address is in a valid memslot */ 100 idx = srcu_read_lock(&kvm->srcu); 101 if (kvm_is_error_hva(gfn_to_hva(kvm, ipa >> PAGE_SHIFT))) 102 ret = -EINVAL; 103 srcu_read_unlock(&kvm->srcu, idx); 104 105 if (!ret) 106 vcpu->arch.steal.base = ipa; 107 108 return ret; 109 } 110 111 int kvm_arm_pvtime_get_attr(struct kvm_vcpu *vcpu, 112 struct kvm_device_attr *attr) 113 { 114 u64 __user *user = (u64 __user *)attr->addr; 115 u64 ipa; 116 117 if (!kvm_arm_pvtime_supported() || 118 attr->attr != KVM_ARM_VCPU_PVTIME_IPA) 119 return -ENXIO; 120 121 ipa = vcpu->arch.steal.base; 122 123 if (put_user(ipa, user)) 124 return -EFAULT; 125 return 0; 126 } 127 128 int kvm_arm_pvtime_has_attr(struct kvm_vcpu *vcpu, 129 struct kvm_device_attr *attr) 130 { 131 switch (attr->attr) { 132 case KVM_ARM_VCPU_PVTIME_IPA: 133 if (kvm_arm_pvtime_supported()) 134 return 0; 135 } 136 return -ENXIO; 137 } 138