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/csr.h>
13 #include <asm/sbi.h>
14 #include <asm/kvm_vcpu_sbi.h>
15
kvm_sbi_hsm_vcpu_start(struct kvm_vcpu * vcpu)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
23 target_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, target_vcpuid);
24 if (!target_vcpu)
25 return -EINVAL;
26 if (!target_vcpu->arch.power_off)
27 return -EALREADY;
28
29 reset_cntx = &target_vcpu->arch.guest_reset_context;
30 /* start address */
31 reset_cntx->sepc = cp->a1;
32 /* target vcpu id to start */
33 reset_cntx->a0 = target_vcpuid;
34 /* private data passed from kernel */
35 reset_cntx->a1 = cp->a2;
36 kvm_make_request(KVM_REQ_VCPU_RESET, target_vcpu);
37
38 kvm_riscv_vcpu_power_on(target_vcpu);
39
40 return 0;
41 }
42
kvm_sbi_hsm_vcpu_stop(struct kvm_vcpu * vcpu)43 static int kvm_sbi_hsm_vcpu_stop(struct kvm_vcpu *vcpu)
44 {
45 if (vcpu->arch.power_off)
46 return -EINVAL;
47
48 kvm_riscv_vcpu_power_off(vcpu);
49
50 return 0;
51 }
52
kvm_sbi_hsm_vcpu_get_status(struct kvm_vcpu * vcpu)53 static int kvm_sbi_hsm_vcpu_get_status(struct kvm_vcpu *vcpu)
54 {
55 struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
56 unsigned long target_vcpuid = cp->a0;
57 struct kvm_vcpu *target_vcpu;
58
59 target_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, target_vcpuid);
60 if (!target_vcpu)
61 return -EINVAL;
62 if (!target_vcpu->arch.power_off)
63 return SBI_HSM_STATE_STARTED;
64 else if (vcpu->stat.generic.blocking)
65 return SBI_HSM_STATE_SUSPENDED;
66 else
67 return SBI_HSM_STATE_STOPPED;
68 }
69
kvm_sbi_ext_hsm_handler(struct kvm_vcpu * vcpu,struct kvm_run * run,unsigned long * out_val,struct kvm_cpu_trap * utrap,bool * exit)70 static int kvm_sbi_ext_hsm_handler(struct kvm_vcpu *vcpu, struct kvm_run *run,
71 unsigned long *out_val,
72 struct kvm_cpu_trap *utrap,
73 bool *exit)
74 {
75 int ret = 0;
76 struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
77 struct kvm *kvm = vcpu->kvm;
78 unsigned long funcid = cp->a6;
79
80 switch (funcid) {
81 case SBI_EXT_HSM_HART_START:
82 mutex_lock(&kvm->lock);
83 ret = kvm_sbi_hsm_vcpu_start(vcpu);
84 mutex_unlock(&kvm->lock);
85 break;
86 case SBI_EXT_HSM_HART_STOP:
87 ret = kvm_sbi_hsm_vcpu_stop(vcpu);
88 break;
89 case SBI_EXT_HSM_HART_STATUS:
90 ret = kvm_sbi_hsm_vcpu_get_status(vcpu);
91 if (ret >= 0) {
92 *out_val = ret;
93 ret = 0;
94 }
95 break;
96 case SBI_EXT_HSM_HART_SUSPEND:
97 switch (cp->a0) {
98 case SBI_HSM_SUSPEND_RET_DEFAULT:
99 kvm_riscv_vcpu_wfi(vcpu);
100 break;
101 case SBI_HSM_SUSPEND_NON_RET_DEFAULT:
102 ret = -EOPNOTSUPP;
103 break;
104 default:
105 ret = -EINVAL;
106 }
107 break;
108 default:
109 ret = -EOPNOTSUPP;
110 }
111
112 return ret;
113 }
114
115 const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_hsm = {
116 .extid_start = SBI_EXT_HSM,
117 .extid_end = SBI_EXT_HSM,
118 .handler = kvm_sbi_ext_hsm_handler,
119 };
120