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/hwcap.h>
15 #include <asm/sbi.h>
16 
kvm_arch_dev_ioctl(struct file * filp,unsigned int ioctl,unsigned long arg)17 long kvm_arch_dev_ioctl(struct file *filp,
18 			unsigned int ioctl, unsigned long arg)
19 {
20 	return -EINVAL;
21 }
22 
kvm_arch_check_processor_compat(void * opaque)23 int kvm_arch_check_processor_compat(void *opaque)
24 {
25 	return 0;
26 }
27 
kvm_arch_hardware_setup(void * opaque)28 int kvm_arch_hardware_setup(void *opaque)
29 {
30 	return 0;
31 }
32 
kvm_arch_hardware_enable(void)33 int kvm_arch_hardware_enable(void)
34 {
35 	unsigned long hideleg, hedeleg;
36 
37 	hedeleg = 0;
38 	hedeleg |= (1UL << EXC_INST_MISALIGNED);
39 	hedeleg |= (1UL << EXC_BREAKPOINT);
40 	hedeleg |= (1UL << EXC_SYSCALL);
41 	hedeleg |= (1UL << EXC_INST_PAGE_FAULT);
42 	hedeleg |= (1UL << EXC_LOAD_PAGE_FAULT);
43 	hedeleg |= (1UL << EXC_STORE_PAGE_FAULT);
44 	csr_write(CSR_HEDELEG, hedeleg);
45 
46 	hideleg = 0;
47 	hideleg |= (1UL << IRQ_VS_SOFT);
48 	hideleg |= (1UL << IRQ_VS_TIMER);
49 	hideleg |= (1UL << IRQ_VS_EXT);
50 	csr_write(CSR_HIDELEG, hideleg);
51 
52 	csr_write(CSR_HCOUNTEREN, -1UL);
53 
54 	csr_write(CSR_HVIP, 0);
55 
56 	return 0;
57 }
58 
kvm_arch_hardware_disable(void)59 void kvm_arch_hardware_disable(void)
60 {
61 	csr_write(CSR_HEDELEG, 0);
62 	csr_write(CSR_HIDELEG, 0);
63 }
64 
kvm_arch_init(void * opaque)65 int kvm_arch_init(void *opaque)
66 {
67 	const char *str;
68 
69 	if (!riscv_isa_extension_available(NULL, h)) {
70 		kvm_info("hypervisor extension not available\n");
71 		return -ENODEV;
72 	}
73 
74 	if (sbi_spec_is_0_1()) {
75 		kvm_info("require SBI v0.2 or higher\n");
76 		return -ENODEV;
77 	}
78 
79 	if (sbi_probe_extension(SBI_EXT_RFENCE) <= 0) {
80 		kvm_info("require SBI RFENCE extension\n");
81 		return -ENODEV;
82 	}
83 
84 	kvm_riscv_stage2_mode_detect();
85 
86 	kvm_riscv_stage2_vmid_detect();
87 
88 	kvm_info("hypervisor extension available\n");
89 
90 	switch (kvm_riscv_stage2_mode()) {
91 	case HGATP_MODE_SV32X4:
92 		str = "Sv32x4";
93 		break;
94 	case HGATP_MODE_SV39X4:
95 		str = "Sv39x4";
96 		break;
97 	case HGATP_MODE_SV48X4:
98 		str = "Sv48x4";
99 		break;
100 	default:
101 		return -ENODEV;
102 	}
103 	kvm_info("using %s G-stage page table format\n", str);
104 
105 	kvm_info("VMID %ld bits available\n", kvm_riscv_stage2_vmid_bits());
106 
107 	return 0;
108 }
109 
kvm_arch_exit(void)110 void kvm_arch_exit(void)
111 {
112 }
113 
riscv_kvm_init(void)114 static int riscv_kvm_init(void)
115 {
116 	return kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
117 }
118 module_init(riscv_kvm_init);
119