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_mmu.h> 8 #include <asm/pvclock-abi.h> 9 10 #include <kvm/arm_hypercalls.h> 11 12 void kvm_update_stolen_time(struct kvm_vcpu *vcpu) 13 { 14 struct kvm *kvm = vcpu->kvm; 15 u64 steal; 16 __le64 steal_le; 17 u64 offset; 18 int idx; 19 u64 base = vcpu->arch.steal.base; 20 21 if (base == GPA_INVALID) 22 return; 23 24 /* Let's do the local bookkeeping */ 25 steal = vcpu->arch.steal.steal; 26 steal += current->sched_info.run_delay - vcpu->arch.steal.last_steal; 27 vcpu->arch.steal.last_steal = current->sched_info.run_delay; 28 vcpu->arch.steal.steal = steal; 29 30 steal_le = cpu_to_le64(steal); 31 idx = srcu_read_lock(&kvm->srcu); 32 offset = offsetof(struct pvclock_vcpu_stolen_time, stolen_time); 33 kvm_put_guest(kvm, base + offset, steal_le, u64); 34 srcu_read_unlock(&kvm->srcu, idx); 35 } 36 37 long kvm_hypercall_pv_features(struct kvm_vcpu *vcpu) 38 { 39 u32 feature = smccc_get_arg1(vcpu); 40 long val = SMCCC_RET_NOT_SUPPORTED; 41 42 switch (feature) { 43 case ARM_SMCCC_HV_PV_TIME_FEATURES: 44 case ARM_SMCCC_HV_PV_TIME_ST: 45 val = SMCCC_RET_SUCCESS; 46 break; 47 } 48 49 return val; 50 } 51 52 gpa_t kvm_init_stolen_time(struct kvm_vcpu *vcpu) 53 { 54 struct pvclock_vcpu_stolen_time init_values = {}; 55 struct kvm *kvm = vcpu->kvm; 56 u64 base = vcpu->arch.steal.base; 57 int idx; 58 59 if (base == GPA_INVALID) 60 return base; 61 62 /* 63 * Start counting stolen time from the time the guest requests 64 * the feature enabled. 65 */ 66 vcpu->arch.steal.steal = 0; 67 vcpu->arch.steal.last_steal = current->sched_info.run_delay; 68 69 idx = srcu_read_lock(&kvm->srcu); 70 kvm_write_guest(kvm, base, &init_values, sizeof(init_values)); 71 srcu_read_unlock(&kvm->srcu, idx); 72 73 return base; 74 } 75 76 int kvm_arm_pvtime_set_attr(struct kvm_vcpu *vcpu, 77 struct kvm_device_attr *attr) 78 { 79 u64 __user *user = (u64 __user *)attr->addr; 80 struct kvm *kvm = vcpu->kvm; 81 u64 ipa; 82 int ret = 0; 83 int idx; 84 85 if (attr->attr != KVM_ARM_VCPU_PVTIME_IPA) 86 return -ENXIO; 87 88 if (get_user(ipa, user)) 89 return -EFAULT; 90 if (!IS_ALIGNED(ipa, 64)) 91 return -EINVAL; 92 if (vcpu->arch.steal.base != GPA_INVALID) 93 return -EEXIST; 94 95 /* Check the address is in a valid memslot */ 96 idx = srcu_read_lock(&kvm->srcu); 97 if (kvm_is_error_hva(gfn_to_hva(kvm, ipa >> PAGE_SHIFT))) 98 ret = -EINVAL; 99 srcu_read_unlock(&kvm->srcu, idx); 100 101 if (!ret) 102 vcpu->arch.steal.base = ipa; 103 104 return ret; 105 } 106 107 int kvm_arm_pvtime_get_attr(struct kvm_vcpu *vcpu, 108 struct kvm_device_attr *attr) 109 { 110 u64 __user *user = (u64 __user *)attr->addr; 111 u64 ipa; 112 113 if (attr->attr != KVM_ARM_VCPU_PVTIME_IPA) 114 return -ENXIO; 115 116 ipa = vcpu->arch.steal.base; 117 118 if (put_user(ipa, user)) 119 return -EFAULT; 120 return 0; 121 } 122 123 int kvm_arm_pvtime_has_attr(struct kvm_vcpu *vcpu, 124 struct kvm_device_attr *attr) 125 { 126 switch (attr->attr) { 127 case KVM_ARM_VCPU_PVTIME_IPA: 128 return 0; 129 } 130 return -ENXIO; 131 } 132