1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2019 Western Digital Corporation or its affiliates.
4 *
5 * Authors:
6 * Anup Patel <anup.patel@wdc.com>
7 */
8
9 #include <linux/errno.h>
10 #include <linux/err.h>
11 #include <linux/module.h>
12 #include <linux/kvm_host.h>
13 #include <asm/cpufeature.h>
14 #include <asm/kvm_mmu.h>
15 #include <asm/kvm_nacl.h>
16 #include <asm/sbi.h>
17
kvm_arch_dev_ioctl(struct file * filp,unsigned int ioctl,unsigned long arg)18 long kvm_arch_dev_ioctl(struct file *filp,
19 unsigned int ioctl, unsigned long arg)
20 {
21 return -EINVAL;
22 }
23
kvm_arch_enable_virtualization_cpu(void)24 int kvm_arch_enable_virtualization_cpu(void)
25 {
26 int rc;
27
28 rc = kvm_riscv_nacl_enable();
29 if (rc)
30 return rc;
31
32 csr_write(CSR_HEDELEG, KVM_HEDELEG_DEFAULT);
33 csr_write(CSR_HIDELEG, KVM_HIDELEG_DEFAULT);
34
35 /* VS should access only the time counter directly. Everything else should trap */
36 csr_write(CSR_HCOUNTEREN, 0x02);
37
38 csr_write(CSR_HVIP, 0);
39
40 kvm_riscv_aia_enable();
41
42 return 0;
43 }
44
kvm_arch_disable_virtualization_cpu(void)45 void kvm_arch_disable_virtualization_cpu(void)
46 {
47 kvm_riscv_aia_disable();
48
49 /*
50 * After clearing the hideleg CSR, the host kernel will receive
51 * spurious interrupts if hvip CSR has pending interrupts and the
52 * corresponding enable bits in vsie CSR are asserted. To avoid it,
53 * hvip CSR and vsie CSR must be cleared before clearing hideleg CSR.
54 */
55 csr_write(CSR_VSIE, 0);
56 csr_write(CSR_HVIP, 0);
57 csr_write(CSR_HEDELEG, 0);
58 csr_write(CSR_HIDELEG, 0);
59
60 kvm_riscv_nacl_disable();
61 }
62
kvm_riscv_teardown(void)63 static void kvm_riscv_teardown(void)
64 {
65 kvm_riscv_aia_exit();
66 kvm_riscv_nacl_exit();
67 kvm_unregister_perf_callbacks();
68 }
69
riscv_kvm_init(void)70 static int __init riscv_kvm_init(void)
71 {
72 int rc;
73 char slist[64];
74 const char *str;
75
76 if (!riscv_isa_extension_available(NULL, h)) {
77 kvm_info("hypervisor extension not available\n");
78 return -ENODEV;
79 }
80
81 if (sbi_spec_is_0_1()) {
82 kvm_info("require SBI v0.2 or higher\n");
83 return -ENODEV;
84 }
85
86 if (!sbi_probe_extension(SBI_EXT_RFENCE)) {
87 kvm_info("require SBI RFENCE extension\n");
88 return -ENODEV;
89 }
90
91 rc = kvm_riscv_nacl_init();
92 if (rc && rc != -ENODEV)
93 return rc;
94
95 kvm_riscv_gstage_mode_detect();
96
97 kvm_riscv_gstage_vmid_detect();
98
99 rc = kvm_riscv_aia_init();
100 if (rc && rc != -ENODEV) {
101 kvm_riscv_nacl_exit();
102 return rc;
103 }
104
105 kvm_info("hypervisor extension available\n");
106
107 if (kvm_riscv_nacl_available()) {
108 rc = 0;
109 slist[0] = '\0';
110 if (kvm_riscv_nacl_sync_csr_available()) {
111 if (rc)
112 strcat(slist, ", ");
113 strcat(slist, "sync_csr");
114 rc++;
115 }
116 if (kvm_riscv_nacl_sync_hfence_available()) {
117 if (rc)
118 strcat(slist, ", ");
119 strcat(slist, "sync_hfence");
120 rc++;
121 }
122 if (kvm_riscv_nacl_sync_sret_available()) {
123 if (rc)
124 strcat(slist, ", ");
125 strcat(slist, "sync_sret");
126 rc++;
127 }
128 if (kvm_riscv_nacl_autoswap_csr_available()) {
129 if (rc)
130 strcat(slist, ", ");
131 strcat(slist, "autoswap_csr");
132 rc++;
133 }
134 kvm_info("using SBI nested acceleration with %s\n",
135 (rc) ? slist : "no features");
136 }
137
138 switch (kvm_riscv_gstage_mode) {
139 case HGATP_MODE_SV32X4:
140 str = "Sv32x4";
141 break;
142 case HGATP_MODE_SV39X4:
143 str = "Sv39x4";
144 break;
145 case HGATP_MODE_SV48X4:
146 str = "Sv48x4";
147 break;
148 case HGATP_MODE_SV57X4:
149 str = "Sv57x4";
150 break;
151 default:
152 return -ENODEV;
153 }
154 kvm_info("using %s G-stage page table format\n", str);
155
156 kvm_info("VMID %ld bits available\n", kvm_riscv_gstage_vmid_bits());
157
158 if (kvm_riscv_aia_available())
159 kvm_info("AIA available with %d guest external interrupts\n",
160 kvm_riscv_aia_nr_hgei);
161
162 kvm_register_perf_callbacks(NULL);
163
164 rc = kvm_init(sizeof(struct kvm_vcpu), 0, THIS_MODULE);
165 if (rc) {
166 kvm_riscv_teardown();
167 return rc;
168 }
169
170 return 0;
171 }
172 module_init(riscv_kvm_init);
173
riscv_kvm_exit(void)174 static void __exit riscv_kvm_exit(void)
175 {
176 kvm_exit();
177
178 kvm_riscv_teardown();
179 }
180 module_exit(riscv_kvm_exit);
181