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_timer.h>
15 #include <asm/kvm_vcpu_sbi.h>
16 
17 static int kvm_sbi_ext_time_handler(struct kvm_vcpu *vcpu, struct kvm_run *run,
18 				    unsigned long *out_val,
19 				    struct kvm_cpu_trap *utrap, bool *exit)
20 {
21 	int ret = 0;
22 	struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
23 	u64 next_cycle;
24 
25 	if (cp->a6 != SBI_EXT_TIME_SET_TIMER)
26 		return -EINVAL;
27 
28 #if __riscv_xlen == 32
29 	next_cycle = ((u64)cp->a1 << 32) | (u64)cp->a0;
30 #else
31 	next_cycle = (u64)cp->a0;
32 #endif
33 	kvm_riscv_vcpu_timer_next_event(vcpu, next_cycle);
34 
35 	return ret;
36 }
37 
38 const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_time = {
39 	.extid_start = SBI_EXT_TIME,
40 	.extid_end = SBI_EXT_TIME,
41 	.handler = kvm_sbi_ext_time_handler,
42 };
43 
44 static int kvm_sbi_ext_ipi_handler(struct kvm_vcpu *vcpu, struct kvm_run *run,
45 				   unsigned long *out_val,
46 				   struct kvm_cpu_trap *utrap, bool *exit)
47 {
48 	int ret = 0;
49 	unsigned long i;
50 	struct kvm_vcpu *tmp;
51 	struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
52 	unsigned long hmask = cp->a0;
53 	unsigned long hbase = cp->a1;
54 
55 	if (cp->a6 != SBI_EXT_IPI_SEND_IPI)
56 		return -EINVAL;
57 
58 	kvm_for_each_vcpu(i, tmp, vcpu->kvm) {
59 		if (hbase != -1UL) {
60 			if (tmp->vcpu_id < hbase)
61 				continue;
62 			if (!(hmask & (1UL << (tmp->vcpu_id - hbase))))
63 				continue;
64 		}
65 		ret = kvm_riscv_vcpu_set_interrupt(tmp, IRQ_VS_SOFT);
66 		if (ret < 0)
67 			break;
68 	}
69 
70 	return ret;
71 }
72 
73 const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_ipi = {
74 	.extid_start = SBI_EXT_IPI,
75 	.extid_end = SBI_EXT_IPI,
76 	.handler = kvm_sbi_ext_ipi_handler,
77 };
78 
79 static int kvm_sbi_ext_rfence_handler(struct kvm_vcpu *vcpu, struct kvm_run *run,
80 				      unsigned long *out_val,
81 				      struct kvm_cpu_trap *utrap, bool *exit)
82 {
83 	int ret = 0;
84 	unsigned long i;
85 	struct cpumask cm;
86 	struct kvm_vcpu *tmp;
87 	struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
88 	unsigned long hmask = cp->a0;
89 	unsigned long hbase = cp->a1;
90 	unsigned long funcid = cp->a6;
91 
92 	cpumask_clear(&cm);
93 	kvm_for_each_vcpu(i, tmp, vcpu->kvm) {
94 		if (hbase != -1UL) {
95 			if (tmp->vcpu_id < hbase)
96 				continue;
97 			if (!(hmask & (1UL << (tmp->vcpu_id - hbase))))
98 				continue;
99 		}
100 		if (tmp->cpu < 0)
101 			continue;
102 		cpumask_set_cpu(tmp->cpu, &cm);
103 	}
104 
105 	switch (funcid) {
106 	case SBI_EXT_RFENCE_REMOTE_FENCE_I:
107 		ret = sbi_remote_fence_i(&cm);
108 		break;
109 	case SBI_EXT_RFENCE_REMOTE_SFENCE_VMA:
110 		ret = sbi_remote_hfence_vvma(&cm, cp->a2, cp->a3);
111 		break;
112 	case SBI_EXT_RFENCE_REMOTE_SFENCE_VMA_ASID:
113 		ret = sbi_remote_hfence_vvma_asid(&cm, cp->a2,
114 						  cp->a3, cp->a4);
115 		break;
116 	case SBI_EXT_RFENCE_REMOTE_HFENCE_GVMA:
117 	case SBI_EXT_RFENCE_REMOTE_HFENCE_GVMA_VMID:
118 	case SBI_EXT_RFENCE_REMOTE_HFENCE_VVMA:
119 	case SBI_EXT_RFENCE_REMOTE_HFENCE_VVMA_ASID:
120 	/* TODO: implement for nested hypervisor case */
121 	default:
122 		ret = -EOPNOTSUPP;
123 	}
124 
125 	return ret;
126 }
127 
128 const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_rfence = {
129 	.extid_start = SBI_EXT_RFENCE,
130 	.extid_end = SBI_EXT_RFENCE,
131 	.handler = kvm_sbi_ext_rfence_handler,
132 };
133 
134 static int kvm_sbi_ext_srst_handler(struct kvm_vcpu *vcpu,
135 				    struct kvm_run *run,
136 				    unsigned long *out_val,
137 				    struct kvm_cpu_trap *utrap, bool *exit)
138 {
139 	struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
140 	unsigned long funcid = cp->a6;
141 	u32 reason = cp->a1;
142 	u32 type = cp->a0;
143 	int ret = 0;
144 
145 	switch (funcid) {
146 	case SBI_EXT_SRST_RESET:
147 		switch (type) {
148 		case SBI_SRST_RESET_TYPE_SHUTDOWN:
149 			kvm_riscv_vcpu_sbi_system_reset(vcpu, run,
150 						KVM_SYSTEM_EVENT_SHUTDOWN,
151 						reason);
152 			*exit = true;
153 			break;
154 		case SBI_SRST_RESET_TYPE_COLD_REBOOT:
155 		case SBI_SRST_RESET_TYPE_WARM_REBOOT:
156 			kvm_riscv_vcpu_sbi_system_reset(vcpu, run,
157 						KVM_SYSTEM_EVENT_RESET,
158 						reason);
159 			*exit = true;
160 			break;
161 		default:
162 			ret = -EOPNOTSUPP;
163 		}
164 		break;
165 	default:
166 		ret = -EOPNOTSUPP;
167 	}
168 
169 	return ret;
170 }
171 
172 const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_srst = {
173 	.extid_start = SBI_EXT_SRST,
174 	.extid_end = SBI_EXT_SRST,
175 	.handler = kvm_sbi_ext_srst_handler,
176 };
177