GNU Linux-libre 6.7.9-gnu
[releases.git] / arch / riscv / kvm / main.c
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/csr.h>
14 #include <asm/cpufeature.h>
15 #include <asm/sbi.h>
16
17 long kvm_arch_dev_ioctl(struct file *filp,
18                         unsigned int ioctl, unsigned long arg)
19 {
20         return -EINVAL;
21 }
22
23 int kvm_arch_hardware_enable(void)
24 {
25         unsigned long hideleg, hedeleg;
26
27         hedeleg = 0;
28         hedeleg |= (1UL << EXC_INST_MISALIGNED);
29         hedeleg |= (1UL << EXC_BREAKPOINT);
30         hedeleg |= (1UL << EXC_SYSCALL);
31         hedeleg |= (1UL << EXC_INST_PAGE_FAULT);
32         hedeleg |= (1UL << EXC_LOAD_PAGE_FAULT);
33         hedeleg |= (1UL << EXC_STORE_PAGE_FAULT);
34         csr_write(CSR_HEDELEG, hedeleg);
35
36         hideleg = 0;
37         hideleg |= (1UL << IRQ_VS_SOFT);
38         hideleg |= (1UL << IRQ_VS_TIMER);
39         hideleg |= (1UL << IRQ_VS_EXT);
40         csr_write(CSR_HIDELEG, hideleg);
41
42         /* VS should access only the time counter directly. Everything else should trap */
43         csr_write(CSR_HCOUNTEREN, 0x02);
44
45         csr_write(CSR_HVIP, 0);
46
47         kvm_riscv_aia_enable();
48
49         return 0;
50 }
51
52 void kvm_arch_hardware_disable(void)
53 {
54         kvm_riscv_aia_disable();
55
56         /*
57          * After clearing the hideleg CSR, the host kernel will receive
58          * spurious interrupts if hvip CSR has pending interrupts and the
59          * corresponding enable bits in vsie CSR are asserted. To avoid it,
60          * hvip CSR and vsie CSR must be cleared before clearing hideleg CSR.
61          */
62         csr_write(CSR_VSIE, 0);
63         csr_write(CSR_HVIP, 0);
64         csr_write(CSR_HEDELEG, 0);
65         csr_write(CSR_HIDELEG, 0);
66 }
67
68 static int __init riscv_kvm_init(void)
69 {
70         int rc;
71         const char *str;
72
73         if (!riscv_isa_extension_available(NULL, h)) {
74                 kvm_info("hypervisor extension not available\n");
75                 return -ENODEV;
76         }
77
78         if (sbi_spec_is_0_1()) {
79                 kvm_info("require SBI v0.2 or higher\n");
80                 return -ENODEV;
81         }
82
83         if (!sbi_probe_extension(SBI_EXT_RFENCE)) {
84                 kvm_info("require SBI RFENCE extension\n");
85                 return -ENODEV;
86         }
87
88         kvm_riscv_gstage_mode_detect();
89
90         kvm_riscv_gstage_vmid_detect();
91
92         rc = kvm_riscv_aia_init();
93         if (rc && rc != -ENODEV)
94                 return rc;
95
96         kvm_info("hypervisor extension available\n");
97
98         switch (kvm_riscv_gstage_mode()) {
99         case HGATP_MODE_SV32X4:
100                 str = "Sv32x4";
101                 break;
102         case HGATP_MODE_SV39X4:
103                 str = "Sv39x4";
104                 break;
105         case HGATP_MODE_SV48X4:
106                 str = "Sv48x4";
107                 break;
108         case HGATP_MODE_SV57X4:
109                 str = "Sv57x4";
110                 break;
111         default:
112                 return -ENODEV;
113         }
114         kvm_info("using %s G-stage page table format\n", str);
115
116         kvm_info("VMID %ld bits available\n", kvm_riscv_gstage_vmid_bits());
117
118         if (kvm_riscv_aia_available())
119                 kvm_info("AIA available with %d guest external interrupts\n",
120                          kvm_riscv_aia_nr_hgei);
121
122         rc = kvm_init(sizeof(struct kvm_vcpu), 0, THIS_MODULE);
123         if (rc) {
124                 kvm_riscv_aia_exit();
125                 return rc;
126         }
127
128         return 0;
129 }
130 module_init(riscv_kvm_init);
131
132 static void __exit riscv_kvm_exit(void)
133 {
134         kvm_riscv_aia_exit();
135
136         kvm_exit();
137 }
138 module_exit(riscv_kvm_exit);