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 <linux/wordpart.h> 13 #include <asm/sbi.h> 14 #include <asm/kvm_vcpu_sbi.h> 15 16 static int kvm_sbi_hsm_vcpu_start(struct kvm_vcpu *vcpu) 17 { 18 struct kvm_cpu_context *reset_cntx; 19 struct kvm_cpu_context *cp = &vcpu->arch.guest_context; 20 struct kvm_vcpu *target_vcpu; 21 unsigned long target_vcpuid = cp->a0; 22 int ret = 0; 23 24 target_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, target_vcpuid); 25 if (!target_vcpu) 26 return SBI_ERR_INVALID_PARAM; 27 28 spin_lock(&target_vcpu->arch.mp_state_lock); 29 30 if (!kvm_riscv_vcpu_stopped(target_vcpu)) { 31 ret = SBI_ERR_ALREADY_AVAILABLE; 32 goto out; 33 } 34 35 spin_lock(&target_vcpu->arch.reset_cntx_lock); 36 reset_cntx = &target_vcpu->arch.guest_reset_context; 37 /* start address */ 38 reset_cntx->sepc = cp->a1; 39 /* target vcpu id to start */ 40 reset_cntx->a0 = target_vcpuid; 41 /* private data passed from kernel */ 42 reset_cntx->a1 = cp->a2; 43 spin_unlock(&target_vcpu->arch.reset_cntx_lock); 44 45 kvm_make_request(KVM_REQ_VCPU_RESET, target_vcpu); 46 47 __kvm_riscv_vcpu_power_on(target_vcpu); 48 49 out: 50 spin_unlock(&target_vcpu->arch.mp_state_lock); 51 52 return ret; 53 } 54 55 static int kvm_sbi_hsm_vcpu_stop(struct kvm_vcpu *vcpu) 56 { 57 int ret = 0; 58 59 spin_lock(&vcpu->arch.mp_state_lock); 60 61 if (kvm_riscv_vcpu_stopped(vcpu)) { 62 ret = SBI_ERR_FAILURE; 63 goto out; 64 } 65 66 __kvm_riscv_vcpu_power_off(vcpu); 67 68 out: 69 spin_unlock(&vcpu->arch.mp_state_lock); 70 71 return ret; 72 } 73 74 static int kvm_sbi_hsm_vcpu_get_status(struct kvm_vcpu *vcpu) 75 { 76 struct kvm_cpu_context *cp = &vcpu->arch.guest_context; 77 unsigned long target_vcpuid = cp->a0; 78 struct kvm_vcpu *target_vcpu; 79 80 target_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, target_vcpuid); 81 if (!target_vcpu) 82 return SBI_ERR_INVALID_PARAM; 83 if (kvm_riscv_vcpu_stopped(target_vcpu)) 84 return SBI_HSM_STATE_STOPPED; 85 else if (target_vcpu->stat.generic.blocking) 86 return SBI_HSM_STATE_SUSPENDED; 87 else 88 return SBI_HSM_STATE_STARTED; 89 } 90 91 static int kvm_sbi_ext_hsm_handler(struct kvm_vcpu *vcpu, struct kvm_run *run, 92 struct kvm_vcpu_sbi_return *retdata) 93 { 94 int ret = 0; 95 struct kvm_cpu_context *cp = &vcpu->arch.guest_context; 96 unsigned long funcid = cp->a6; 97 98 switch (funcid) { 99 case SBI_EXT_HSM_HART_START: 100 ret = kvm_sbi_hsm_vcpu_start(vcpu); 101 break; 102 case SBI_EXT_HSM_HART_STOP: 103 ret = kvm_sbi_hsm_vcpu_stop(vcpu); 104 break; 105 case SBI_EXT_HSM_HART_STATUS: 106 ret = kvm_sbi_hsm_vcpu_get_status(vcpu); 107 if (ret >= 0) { 108 retdata->out_val = ret; 109 retdata->err_val = 0; 110 } 111 return 0; 112 case SBI_EXT_HSM_HART_SUSPEND: 113 switch (lower_32_bits(cp->a0)) { 114 case SBI_HSM_SUSPEND_RET_DEFAULT: 115 kvm_riscv_vcpu_wfi(vcpu); 116 break; 117 case SBI_HSM_SUSPEND_NON_RET_DEFAULT: 118 ret = SBI_ERR_NOT_SUPPORTED; 119 break; 120 default: 121 ret = SBI_ERR_INVALID_PARAM; 122 } 123 break; 124 default: 125 ret = SBI_ERR_NOT_SUPPORTED; 126 } 127 128 retdata->err_val = ret; 129 130 return 0; 131 } 132 133 const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_hsm = { 134 .extid_start = SBI_EXT_HSM, 135 .extid_end = SBI_EXT_HSM, 136 .handler = kvm_sbi_ext_hsm_handler, 137 }; 138