1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (c) 2019 Western Digital Corporation or its affiliates. 4 * 5 * Authors: 6 * Atish Patra <atish.patra@wdc.com> 7 */ 8 9 #include <linux/errno.h> 10 #include <linux/err.h> 11 #include <linux/kvm_host.h> 12 #include <asm/sbi.h> 13 #include <asm/kvm_vcpu_sbi.h> 14 15 static int kvm_linux_err_map_sbi(int err) 16 { 17 switch (err) { 18 case 0: 19 return SBI_SUCCESS; 20 case -EPERM: 21 return SBI_ERR_DENIED; 22 case -EINVAL: 23 return SBI_ERR_INVALID_PARAM; 24 case -EFAULT: 25 return SBI_ERR_INVALID_ADDRESS; 26 case -EOPNOTSUPP: 27 return SBI_ERR_NOT_SUPPORTED; 28 case -EALREADY: 29 return SBI_ERR_ALREADY_AVAILABLE; 30 default: 31 return SBI_ERR_FAILURE; 32 }; 33 } 34 35 #ifdef CONFIG_RISCV_SBI_V01 36 extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_v01; 37 #else 38 static const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_v01 = { 39 .extid_start = -1UL, 40 .extid_end = -1UL, 41 .handler = NULL, 42 }; 43 #endif 44 extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_base; 45 extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_time; 46 extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_ipi; 47 extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_rfence; 48 extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_srst; 49 extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_hsm; 50 extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_experimental; 51 extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_vendor; 52 53 static const struct kvm_vcpu_sbi_extension *sbi_ext[] = { 54 &vcpu_sbi_ext_v01, 55 &vcpu_sbi_ext_base, 56 &vcpu_sbi_ext_time, 57 &vcpu_sbi_ext_ipi, 58 &vcpu_sbi_ext_rfence, 59 &vcpu_sbi_ext_srst, 60 &vcpu_sbi_ext_hsm, 61 &vcpu_sbi_ext_experimental, 62 &vcpu_sbi_ext_vendor, 63 }; 64 65 void kvm_riscv_vcpu_sbi_forward(struct kvm_vcpu *vcpu, struct kvm_run *run) 66 { 67 struct kvm_cpu_context *cp = &vcpu->arch.guest_context; 68 69 vcpu->arch.sbi_context.return_handled = 0; 70 vcpu->stat.ecall_exit_stat++; 71 run->exit_reason = KVM_EXIT_RISCV_SBI; 72 run->riscv_sbi.extension_id = cp->a7; 73 run->riscv_sbi.function_id = cp->a6; 74 run->riscv_sbi.args[0] = cp->a0; 75 run->riscv_sbi.args[1] = cp->a1; 76 run->riscv_sbi.args[2] = cp->a2; 77 run->riscv_sbi.args[3] = cp->a3; 78 run->riscv_sbi.args[4] = cp->a4; 79 run->riscv_sbi.args[5] = cp->a5; 80 run->riscv_sbi.ret[0] = cp->a0; 81 run->riscv_sbi.ret[1] = cp->a1; 82 } 83 84 void kvm_riscv_vcpu_sbi_system_reset(struct kvm_vcpu *vcpu, 85 struct kvm_run *run, 86 u32 type, u64 flags) 87 { 88 unsigned long i; 89 struct kvm_vcpu *tmp; 90 91 kvm_for_each_vcpu(i, tmp, vcpu->kvm) 92 tmp->arch.power_off = true; 93 kvm_make_all_cpus_request(vcpu->kvm, KVM_REQ_SLEEP); 94 95 memset(&run->system_event, 0, sizeof(run->system_event)); 96 run->system_event.type = type; 97 run->system_event.flags = flags; 98 run->exit_reason = KVM_EXIT_SYSTEM_EVENT; 99 } 100 101 int kvm_riscv_vcpu_sbi_return(struct kvm_vcpu *vcpu, struct kvm_run *run) 102 { 103 struct kvm_cpu_context *cp = &vcpu->arch.guest_context; 104 105 /* Handle SBI return only once */ 106 if (vcpu->arch.sbi_context.return_handled) 107 return 0; 108 vcpu->arch.sbi_context.return_handled = 1; 109 110 /* Update return values */ 111 cp->a0 = run->riscv_sbi.ret[0]; 112 cp->a1 = run->riscv_sbi.ret[1]; 113 114 /* Move to next instruction */ 115 vcpu->arch.guest_context.sepc += 4; 116 117 return 0; 118 } 119 120 const struct kvm_vcpu_sbi_extension *kvm_vcpu_sbi_find_ext(unsigned long extid) 121 { 122 int i = 0; 123 124 for (i = 0; i < ARRAY_SIZE(sbi_ext); i++) { 125 if (sbi_ext[i]->extid_start <= extid && 126 sbi_ext[i]->extid_end >= extid) 127 return sbi_ext[i]; 128 } 129 130 return NULL; 131 } 132 133 int kvm_riscv_vcpu_sbi_ecall(struct kvm_vcpu *vcpu, struct kvm_run *run) 134 { 135 int ret = 1; 136 bool next_sepc = true; 137 bool userspace_exit = false; 138 struct kvm_cpu_context *cp = &vcpu->arch.guest_context; 139 const struct kvm_vcpu_sbi_extension *sbi_ext; 140 struct kvm_cpu_trap utrap = { 0 }; 141 unsigned long out_val = 0; 142 bool ext_is_v01 = false; 143 144 sbi_ext = kvm_vcpu_sbi_find_ext(cp->a7); 145 if (sbi_ext && sbi_ext->handler) { 146 #ifdef CONFIG_RISCV_SBI_V01 147 if (cp->a7 >= SBI_EXT_0_1_SET_TIMER && 148 cp->a7 <= SBI_EXT_0_1_SHUTDOWN) 149 ext_is_v01 = true; 150 #endif 151 ret = sbi_ext->handler(vcpu, run, &out_val, &utrap, &userspace_exit); 152 } else { 153 /* Return error for unsupported SBI calls */ 154 cp->a0 = SBI_ERR_NOT_SUPPORTED; 155 goto ecall_done; 156 } 157 158 /* Handle special error cases i.e trap, exit or userspace forward */ 159 if (utrap.scause) { 160 /* No need to increment sepc or exit ioctl loop */ 161 ret = 1; 162 utrap.sepc = cp->sepc; 163 kvm_riscv_vcpu_trap_redirect(vcpu, &utrap); 164 next_sepc = false; 165 goto ecall_done; 166 } 167 168 /* Exit ioctl loop or Propagate the error code the guest */ 169 if (userspace_exit) { 170 next_sepc = false; 171 ret = 0; 172 } else { 173 /** 174 * SBI extension handler always returns an Linux error code. Convert 175 * it to the SBI specific error code that can be propagated the SBI 176 * caller. 177 */ 178 ret = kvm_linux_err_map_sbi(ret); 179 cp->a0 = ret; 180 ret = 1; 181 } 182 ecall_done: 183 if (next_sepc) 184 cp->sepc += 4; 185 if (!ext_is_v01) 186 cp->a1 = out_val; 187 188 return ret; 189 } 190