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_hsm; 49 extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_experimental; 50 extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_vendor; 51 52 static const struct kvm_vcpu_sbi_extension *sbi_ext[] = { 53 &vcpu_sbi_ext_v01, 54 &vcpu_sbi_ext_base, 55 &vcpu_sbi_ext_time, 56 &vcpu_sbi_ext_ipi, 57 &vcpu_sbi_ext_rfence, 58 &vcpu_sbi_ext_hsm, 59 &vcpu_sbi_ext_experimental, 60 &vcpu_sbi_ext_vendor, 61 }; 62 63 void kvm_riscv_vcpu_sbi_forward(struct kvm_vcpu *vcpu, struct kvm_run *run) 64 { 65 struct kvm_cpu_context *cp = &vcpu->arch.guest_context; 66 67 vcpu->arch.sbi_context.return_handled = 0; 68 vcpu->stat.ecall_exit_stat++; 69 run->exit_reason = KVM_EXIT_RISCV_SBI; 70 run->riscv_sbi.extension_id = cp->a7; 71 run->riscv_sbi.function_id = cp->a6; 72 run->riscv_sbi.args[0] = cp->a0; 73 run->riscv_sbi.args[1] = cp->a1; 74 run->riscv_sbi.args[2] = cp->a2; 75 run->riscv_sbi.args[3] = cp->a3; 76 run->riscv_sbi.args[4] = cp->a4; 77 run->riscv_sbi.args[5] = cp->a5; 78 run->riscv_sbi.ret[0] = cp->a0; 79 run->riscv_sbi.ret[1] = cp->a1; 80 } 81 82 int kvm_riscv_vcpu_sbi_return(struct kvm_vcpu *vcpu, struct kvm_run *run) 83 { 84 struct kvm_cpu_context *cp = &vcpu->arch.guest_context; 85 86 /* Handle SBI return only once */ 87 if (vcpu->arch.sbi_context.return_handled) 88 return 0; 89 vcpu->arch.sbi_context.return_handled = 1; 90 91 /* Update return values */ 92 cp->a0 = run->riscv_sbi.ret[0]; 93 cp->a1 = run->riscv_sbi.ret[1]; 94 95 /* Move to next instruction */ 96 vcpu->arch.guest_context.sepc += 4; 97 98 return 0; 99 } 100 101 const struct kvm_vcpu_sbi_extension *kvm_vcpu_sbi_find_ext(unsigned long extid) 102 { 103 int i = 0; 104 105 for (i = 0; i < ARRAY_SIZE(sbi_ext); i++) { 106 if (sbi_ext[i]->extid_start <= extid && 107 sbi_ext[i]->extid_end >= extid) 108 return sbi_ext[i]; 109 } 110 111 return NULL; 112 } 113 114 int kvm_riscv_vcpu_sbi_ecall(struct kvm_vcpu *vcpu, struct kvm_run *run) 115 { 116 int ret = 1; 117 bool next_sepc = true; 118 bool userspace_exit = false; 119 struct kvm_cpu_context *cp = &vcpu->arch.guest_context; 120 const struct kvm_vcpu_sbi_extension *sbi_ext; 121 struct kvm_cpu_trap utrap = { 0 }; 122 unsigned long out_val = 0; 123 bool ext_is_v01 = false; 124 125 sbi_ext = kvm_vcpu_sbi_find_ext(cp->a7); 126 if (sbi_ext && sbi_ext->handler) { 127 #ifdef CONFIG_RISCV_SBI_V01 128 if (cp->a7 >= SBI_EXT_0_1_SET_TIMER && 129 cp->a7 <= SBI_EXT_0_1_SHUTDOWN) 130 ext_is_v01 = true; 131 #endif 132 ret = sbi_ext->handler(vcpu, run, &out_val, &utrap, &userspace_exit); 133 } else { 134 /* Return error for unsupported SBI calls */ 135 cp->a0 = SBI_ERR_NOT_SUPPORTED; 136 goto ecall_done; 137 } 138 139 /* Handle special error cases i.e trap, exit or userspace forward */ 140 if (utrap.scause) { 141 /* No need to increment sepc or exit ioctl loop */ 142 ret = 1; 143 utrap.sepc = cp->sepc; 144 kvm_riscv_vcpu_trap_redirect(vcpu, &utrap); 145 next_sepc = false; 146 goto ecall_done; 147 } 148 149 /* Exit ioctl loop or Propagate the error code the guest */ 150 if (userspace_exit) { 151 next_sepc = false; 152 ret = 0; 153 } else { 154 /** 155 * SBI extension handler always returns an Linux error code. Convert 156 * it to the SBI specific error code that can be propagated the SBI 157 * caller. 158 */ 159 ret = kvm_linux_err_map_sbi(ret); 160 cp->a0 = ret; 161 ret = 1; 162 } 163 ecall_done: 164 if (next_sepc) 165 cp->sepc += 4; 166 if (!ext_is_v01) 167 cp->a1 = out_val; 168 169 return ret; 170 } 171