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
kvm_sbi_hsm_vcpu_start(struct kvm_vcpu * vcpu)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
22 target_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, target_vcpuid);
23 if (!target_vcpu)
24 return SBI_ERR_INVALID_PARAM;
25 if (!target_vcpu->arch.power_off)
26 return SBI_ERR_ALREADY_AVAILABLE;
27
28 reset_cntx = &target_vcpu->arch.guest_reset_context;
29 /* start address */
30 reset_cntx->sepc = cp->a1;
31 /* target vcpu id to start */
32 reset_cntx->a0 = target_vcpuid;
33 /* private data passed from kernel */
34 reset_cntx->a1 = cp->a2;
35 kvm_make_request(KVM_REQ_VCPU_RESET, target_vcpu);
36
37 kvm_riscv_vcpu_power_on(target_vcpu);
38
39 return 0;
40 }
41
kvm_sbi_hsm_vcpu_stop(struct kvm_vcpu * vcpu)42 static int kvm_sbi_hsm_vcpu_stop(struct kvm_vcpu *vcpu)
43 {
44 if (vcpu->arch.power_off)
45 return SBI_ERR_FAILURE;
46
47 kvm_riscv_vcpu_power_off(vcpu);
48
49 return 0;
50 }
51
kvm_sbi_hsm_vcpu_get_status(struct kvm_vcpu * vcpu)52 static int kvm_sbi_hsm_vcpu_get_status(struct kvm_vcpu *vcpu)
53 {
54 struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
55 unsigned long target_vcpuid = cp->a0;
56 struct kvm_vcpu *target_vcpu;
57
58 target_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, target_vcpuid);
59 if (!target_vcpu)
60 return SBI_ERR_INVALID_PARAM;
61 if (!target_vcpu->arch.power_off)
62 return SBI_HSM_STATE_STARTED;
63 else if (vcpu->stat.generic.blocking)
64 return SBI_HSM_STATE_SUSPENDED;
65 else
66 return SBI_HSM_STATE_STOPPED;
67 }
68
kvm_sbi_ext_hsm_handler(struct kvm_vcpu * vcpu,struct kvm_run * run,struct kvm_vcpu_sbi_return * retdata)69 static int kvm_sbi_ext_hsm_handler(struct kvm_vcpu *vcpu, struct kvm_run *run,
70 struct kvm_vcpu_sbi_return *retdata)
71 {
72 int ret = 0;
73 struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
74 struct kvm *kvm = vcpu->kvm;
75 unsigned long funcid = cp->a6;
76
77 switch (funcid) {
78 case SBI_EXT_HSM_HART_START:
79 mutex_lock(&kvm->lock);
80 ret = kvm_sbi_hsm_vcpu_start(vcpu);
81 mutex_unlock(&kvm->lock);
82 break;
83 case SBI_EXT_HSM_HART_STOP:
84 ret = kvm_sbi_hsm_vcpu_stop(vcpu);
85 break;
86 case SBI_EXT_HSM_HART_STATUS:
87 ret = kvm_sbi_hsm_vcpu_get_status(vcpu);
88 if (ret >= 0) {
89 retdata->out_val = ret;
90 retdata->err_val = 0;
91 }
92 return 0;
93 case SBI_EXT_HSM_HART_SUSPEND:
94 switch (cp->a0) {
95 case SBI_HSM_SUSPEND_RET_DEFAULT:
96 kvm_riscv_vcpu_wfi(vcpu);
97 break;
98 case SBI_HSM_SUSPEND_NON_RET_DEFAULT:
99 ret = SBI_ERR_NOT_SUPPORTED;
100 break;
101 default:
102 ret = SBI_ERR_INVALID_PARAM;
103 }
104 break;
105 default:
106 ret = SBI_ERR_NOT_SUPPORTED;
107 }
108
109 retdata->err_val = ret;
110
111 return 0;
112 }
113
114 const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_hsm = {
115 .extid_start = SBI_EXT_HSM,
116 .extid_end = SBI_EXT_HSM,
117 .handler = kvm_sbi_ext_hsm_handler,
118 };
119