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 
kvm_sbi_ext_v01_handler(struct kvm_vcpu * vcpu,struct kvm_run * run,unsigned long * out_val,struct kvm_cpu_trap * utrap,bool * exit)17 static int kvm_sbi_ext_v01_handler(struct kvm_vcpu *vcpu, struct kvm_run *run,
18 				      unsigned long *out_val,
19 				      struct kvm_cpu_trap *utrap,
20 				      bool *exit)
21 {
22 	ulong hmask;
23 	int i, ret = 0;
24 	u64 next_cycle;
25 	struct kvm_vcpu *rvcpu;
26 	struct kvm *kvm = vcpu->kvm;
27 	struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
28 
29 	switch (cp->a7) {
30 	case SBI_EXT_0_1_CONSOLE_GETCHAR:
31 	case SBI_EXT_0_1_CONSOLE_PUTCHAR:
32 		/*
33 		 * The CONSOLE_GETCHAR/CONSOLE_PUTCHAR SBI calls cannot be
34 		 * handled in kernel so we forward these to user-space
35 		 */
36 		kvm_riscv_vcpu_sbi_forward(vcpu, run);
37 		*exit = true;
38 		break;
39 	case SBI_EXT_0_1_SET_TIMER:
40 #if __riscv_xlen == 32
41 		next_cycle = ((u64)cp->a1 << 32) | (u64)cp->a0;
42 #else
43 		next_cycle = (u64)cp->a0;
44 #endif
45 		ret = kvm_riscv_vcpu_timer_next_event(vcpu, next_cycle);
46 		break;
47 	case SBI_EXT_0_1_CLEAR_IPI:
48 		ret = kvm_riscv_vcpu_unset_interrupt(vcpu, IRQ_VS_SOFT);
49 		break;
50 	case SBI_EXT_0_1_SEND_IPI:
51 		if (cp->a0)
52 			hmask = kvm_riscv_vcpu_unpriv_read(vcpu, false, cp->a0,
53 							   utrap);
54 		else
55 			hmask = (1UL << atomic_read(&kvm->online_vcpus)) - 1;
56 		if (utrap->scause)
57 			break;
58 
59 		for_each_set_bit(i, &hmask, BITS_PER_LONG) {
60 			rvcpu = kvm_get_vcpu_by_id(vcpu->kvm, i);
61 			ret = kvm_riscv_vcpu_set_interrupt(rvcpu, IRQ_VS_SOFT);
62 			if (ret < 0)
63 				break;
64 		}
65 		break;
66 	case SBI_EXT_0_1_SHUTDOWN:
67 		kvm_riscv_vcpu_sbi_system_reset(vcpu, run,
68 						KVM_SYSTEM_EVENT_SHUTDOWN, 0);
69 		*exit = true;
70 		break;
71 	case SBI_EXT_0_1_REMOTE_FENCE_I:
72 	case SBI_EXT_0_1_REMOTE_SFENCE_VMA:
73 	case SBI_EXT_0_1_REMOTE_SFENCE_VMA_ASID:
74 		if (cp->a0)
75 			hmask = kvm_riscv_vcpu_unpriv_read(vcpu, false, cp->a0,
76 							   utrap);
77 		else
78 			hmask = (1UL << atomic_read(&kvm->online_vcpus)) - 1;
79 		if (utrap->scause)
80 			break;
81 
82 		if (cp->a7 == SBI_EXT_0_1_REMOTE_FENCE_I)
83 			kvm_riscv_fence_i(vcpu->kvm, 0, hmask);
84 		else if (cp->a7 == SBI_EXT_0_1_REMOTE_SFENCE_VMA) {
85 			if (cp->a1 == 0 && cp->a2 == 0)
86 				kvm_riscv_hfence_vvma_all(vcpu->kvm,
87 							  0, hmask);
88 			else
89 				kvm_riscv_hfence_vvma_gva(vcpu->kvm,
90 							  0, hmask,
91 							  cp->a1, cp->a2,
92 							  PAGE_SHIFT);
93 		} else {
94 			if (cp->a1 == 0 && cp->a2 == 0)
95 				kvm_riscv_hfence_vvma_asid_all(vcpu->kvm,
96 							       0, hmask,
97 							       cp->a3);
98 			else
99 				kvm_riscv_hfence_vvma_asid_gva(vcpu->kvm,
100 							       0, hmask,
101 							       cp->a1, cp->a2,
102 							       PAGE_SHIFT,
103 							       cp->a3);
104 		}
105 		break;
106 	default:
107 		ret = -EINVAL;
108 		break;
109 	}
110 
111 	return ret;
112 }
113 
114 const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_v01 = {
115 	.extid_start = SBI_EXT_0_1_SET_TIMER,
116 	.extid_end = SBI_EXT_0_1_SHUTDOWN,
117 	.handler = kvm_sbi_ext_v01_handler,
118 };
119