1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (c) 2021 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_sbi_hsm_vcpu_start(struct kvm_vcpu *vcpu) 16 { 17 struct kvm_cpu_context *reset_cntx; 18 struct kvm_cpu_context *cp = &vcpu->arch.guest_context; 19 struct kvm_vcpu *target_vcpu; 20 unsigned long target_vcpuid = cp->a0; 21 int ret = 0; 22 23 target_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, target_vcpuid); 24 if (!target_vcpu) 25 return SBI_ERR_INVALID_PARAM; 26 27 spin_lock(&target_vcpu->arch.mp_state_lock); 28 29 if (!kvm_riscv_vcpu_stopped(target_vcpu)) { 30 ret = SBI_ERR_ALREADY_AVAILABLE; 31 goto out; 32 } 33 34 spin_lock(&target_vcpu->arch.reset_cntx_lock); 35 reset_cntx = &target_vcpu->arch.guest_reset_context; 36 /* start address */ 37 reset_cntx->sepc = cp->a1; 38 /* target vcpu id to start */ 39 reset_cntx->a0 = target_vcpuid; 40 /* private data passed from kernel */ 41 reset_cntx->a1 = cp->a2; 42 spin_unlock(&target_vcpu->arch.reset_cntx_lock); 43 44 kvm_make_request(KVM_REQ_VCPU_RESET, target_vcpu); 45 46 __kvm_riscv_vcpu_power_on(target_vcpu); 47 48 out: 49 spin_unlock(&target_vcpu->arch.mp_state_lock); 50 51 return ret; 52 } 53 54 static int kvm_sbi_hsm_vcpu_stop(struct kvm_vcpu *vcpu) 55 { 56 int ret = 0; 57 58 spin_lock(&vcpu->arch.mp_state_lock); 59 60 if (kvm_riscv_vcpu_stopped(vcpu)) { 61 ret = SBI_ERR_FAILURE; 62 goto out; 63 } 64 65 __kvm_riscv_vcpu_power_off(vcpu); 66 67 out: 68 spin_unlock(&vcpu->arch.mp_state_lock); 69 70 return ret; 71 } 72 73 static int kvm_sbi_hsm_vcpu_get_status(struct kvm_vcpu *vcpu) 74 { 75 struct kvm_cpu_context *cp = &vcpu->arch.guest_context; 76 unsigned long target_vcpuid = cp->a0; 77 struct kvm_vcpu *target_vcpu; 78 79 target_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, target_vcpuid); 80 if (!target_vcpu) 81 return SBI_ERR_INVALID_PARAM; 82 if (!kvm_riscv_vcpu_stopped(target_vcpu)) 83 return SBI_HSM_STATE_STARTED; 84 else if (vcpu->stat.generic.blocking) 85 return SBI_HSM_STATE_SUSPENDED; 86 else 87 return SBI_HSM_STATE_STOPPED; 88 } 89 90 static int kvm_sbi_ext_hsm_handler(struct kvm_vcpu *vcpu, struct kvm_run *run, 91 struct kvm_vcpu_sbi_return *retdata) 92 { 93 int ret = 0; 94 struct kvm_cpu_context *cp = &vcpu->arch.guest_context; 95 unsigned long funcid = cp->a6; 96 97 switch (funcid) { 98 case SBI_EXT_HSM_HART_START: 99 ret = kvm_sbi_hsm_vcpu_start(vcpu); 100 break; 101 case SBI_EXT_HSM_HART_STOP: 102 ret = kvm_sbi_hsm_vcpu_stop(vcpu); 103 break; 104 case SBI_EXT_HSM_HART_STATUS: 105 ret = kvm_sbi_hsm_vcpu_get_status(vcpu); 106 if (ret >= 0) { 107 retdata->out_val = ret; 108 retdata->err_val = 0; 109 } 110 return 0; 111 case SBI_EXT_HSM_HART_SUSPEND: 112 switch (cp->a0) { 113 case SBI_HSM_SUSPEND_RET_DEFAULT: 114 kvm_riscv_vcpu_wfi(vcpu); 115 break; 116 case SBI_HSM_SUSPEND_NON_RET_DEFAULT: 117 ret = SBI_ERR_NOT_SUPPORTED; 118 break; 119 default: 120 ret = SBI_ERR_INVALID_PARAM; 121 } 122 break; 123 default: 124 ret = SBI_ERR_NOT_SUPPORTED; 125 } 126 127 retdata->err_val = ret; 128 129 return 0; 130 } 131 132 const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_hsm = { 133 .extid_start = SBI_EXT_HSM, 134 .extid_end = SBI_EXT_HSM, 135 .handler = kvm_sbi_ext_hsm_handler, 136 }; 137