Commit | Line | Data |
---|---|---|
d94d71cb | 1 | // SPDX-License-Identifier: GPL-2.0-only |
45e96ea6 CD |
2 | /* |
3 | * Copyright (C) 2012 - Virtual Open Systems and Columbia University | |
4 | * Author: Christoffer Dall <c.dall@virtualopensystems.com> | |
45e96ea6 CD |
5 | */ |
6 | ||
7 | #include <linux/kvm_host.h> | |
45e96ea6 CD |
8 | #include <asm/kvm_emulate.h> |
9 | #include <trace/events/kvm.h> | |
10 | ||
11 | #include "trace.h" | |
12 | ||
d5a5a0ef | 13 | void kvm_mmio_write_buf(void *buf, unsigned int len, unsigned long data) |
6d89d2d9 MZ |
14 | { |
15 | void *datap = NULL; | |
16 | union { | |
17 | u8 byte; | |
18 | u16 hword; | |
19 | u32 word; | |
20 | u64 dword; | |
21 | } tmp; | |
22 | ||
23 | switch (len) { | |
24 | case 1: | |
25 | tmp.byte = data; | |
26 | datap = &tmp.byte; | |
27 | break; | |
28 | case 2: | |
29 | tmp.hword = data; | |
30 | datap = &tmp.hword; | |
31 | break; | |
32 | case 4: | |
33 | tmp.word = data; | |
34 | datap = &tmp.word; | |
35 | break; | |
36 | case 8: | |
37 | tmp.dword = data; | |
38 | datap = &tmp.dword; | |
39 | break; | |
40 | } | |
41 | ||
42 | memcpy(buf, datap, len); | |
43 | } | |
44 | ||
d5a5a0ef | 45 | unsigned long kvm_mmio_read_buf(const void *buf, unsigned int len) |
6d89d2d9 MZ |
46 | { |
47 | unsigned long data = 0; | |
48 | union { | |
49 | u16 hword; | |
50 | u32 word; | |
51 | u64 dword; | |
52 | } tmp; | |
53 | ||
54 | switch (len) { | |
55 | case 1: | |
d5a5a0ef | 56 | data = *(u8 *)buf; |
6d89d2d9 MZ |
57 | break; |
58 | case 2: | |
59 | memcpy(&tmp.hword, buf, len); | |
60 | data = tmp.hword; | |
61 | break; | |
62 | case 4: | |
63 | memcpy(&tmp.word, buf, len); | |
64 | data = tmp.word; | |
65 | break; | |
66 | case 8: | |
67 | memcpy(&tmp.dword, buf, len); | |
68 | data = tmp.dword; | |
69 | break; | |
70 | } | |
71 | ||
72 | return data; | |
73 | } | |
74 | ||
45e96ea6 CD |
75 | /** |
76 | * kvm_handle_mmio_return -- Handle MMIO loads after user space emulation | |
83091db9 CD |
77 | * or in-kernel IO emulation |
78 | * | |
45e96ea6 | 79 | * @vcpu: The VCPU pointer |
45e96ea6 | 80 | */ |
74cc7e0c | 81 | int kvm_handle_mmio_return(struct kvm_vcpu *vcpu) |
45e96ea6 | 82 | { |
6d89d2d9 | 83 | unsigned long data; |
45e96ea6 CD |
84 | unsigned int len; |
85 | int mask; | |
86 | ||
2113c5f6 AJ |
87 | /* Detect an already handled MMIO return */ |
88 | if (unlikely(!vcpu->mmio_needed)) | |
89 | return 0; | |
90 | ||
91 | vcpu->mmio_needed = 0; | |
92 | ||
0e20f5e2 | 93 | if (!kvm_vcpu_dabt_iswrite(vcpu)) { |
74cc7e0c TZ |
94 | struct kvm_run *run = vcpu->run; |
95 | ||
0e20f5e2 | 96 | len = kvm_vcpu_dabt_get_as(vcpu); |
d5a5a0ef | 97 | data = kvm_mmio_read_buf(run->mmio.data, len); |
45e96ea6 | 98 | |
0e20f5e2 | 99 | if (kvm_vcpu_dabt_issext(vcpu) && |
f42798c6 | 100 | len < sizeof(unsigned long)) { |
45e96ea6 | 101 | mask = 1U << ((len * 8) - 1); |
6d89d2d9 | 102 | data = (data ^ mask) - mask; |
45e96ea6 | 103 | } |
6d89d2d9 | 104 | |
0e20f5e2 | 105 | if (!kvm_vcpu_dabt_issf(vcpu)) |
b6ae256a CD |
106 | data = data & 0xffffffff; |
107 | ||
6d89d2d9 | 108 | trace_kvm_mmio(KVM_TRACE_MMIO_READ, len, run->mmio.phys_addr, |
e39d200f | 109 | &data); |
6d89d2d9 | 110 | data = vcpu_data_host_to_guest(vcpu, data, len); |
0e20f5e2 | 111 | vcpu_set_reg(vcpu, kvm_vcpu_dabt_get_rd(vcpu), data); |
45e96ea6 CD |
112 | } |
113 | ||
0d640732 MR |
114 | /* |
115 | * The MMIO instruction is emulated and should not be re-executed | |
116 | * in the guest. | |
117 | */ | |
cdb5e02e | 118 | kvm_incr_pc(vcpu); |
0d640732 | 119 | |
45e96ea6 CD |
120 | return 0; |
121 | } | |
122 | ||
74cc7e0c | 123 | int io_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa) |
45e96ea6 | 124 | { |
74cc7e0c | 125 | struct kvm_run *run = vcpu->run; |
6d89d2d9 | 126 | unsigned long data; |
45e96ea6 CD |
127 | unsigned long rt; |
128 | int ret; | |
950324ab AP |
129 | bool is_write; |
130 | int len; | |
131 | u8 data_buf[8]; | |
45e96ea6 CD |
132 | |
133 | /* | |
0e20f5e2 | 134 | * No valid syndrome? Ask userspace for help if it has |
656012c7 | 135 | * volunteered to do so, and bail out otherwise. |
45e96ea6 | 136 | */ |
0e20f5e2 | 137 | if (!kvm_vcpu_dabt_isvalid(vcpu)) { |
c726200d CD |
138 | if (vcpu->kvm->arch.return_nisv_io_abort_to_user) { |
139 | run->exit_reason = KVM_EXIT_ARM_NISV; | |
140 | run->arm_nisv.esr_iss = kvm_vcpu_dabt_iss_nisv_sanitized(vcpu); | |
141 | run->arm_nisv.fault_ipa = fault_ipa; | |
142 | return 0; | |
143 | } | |
144 | ||
145 | kvm_pr_unimpl("Data abort outside memslots with no valid syndrome info\n"); | |
45e96ea6 CD |
146 | return -ENOSYS; |
147 | } | |
148 | ||
0e20f5e2 MZ |
149 | /* |
150 | * Prepare MMIO operation. First decode the syndrome data we get | |
151 | * from the CPU. Then try if some in-kernel emulation feels | |
152 | * responsible, otherwise let user space do its magic. | |
153 | */ | |
154 | is_write = kvm_vcpu_dabt_iswrite(vcpu); | |
155 | len = kvm_vcpu_dabt_get_as(vcpu); | |
156 | rt = kvm_vcpu_dabt_get_rd(vcpu); | |
6d89d2d9 | 157 | |
950324ab | 158 | if (is_write) { |
bc45a516 PF |
159 | data = vcpu_data_guest_to_host(vcpu, vcpu_get_reg(vcpu, rt), |
160 | len); | |
950324ab | 161 | |
e39d200f | 162 | trace_kvm_mmio(KVM_TRACE_MMIO_WRITE, len, fault_ipa, &data); |
d5a5a0ef | 163 | kvm_mmio_write_buf(data_buf, len, data); |
45e96ea6 | 164 | |
950324ab AP |
165 | ret = kvm_io_bus_write(vcpu, KVM_MMIO_BUS, fault_ipa, len, |
166 | data_buf); | |
5100f983 | 167 | } else { |
950324ab | 168 | trace_kvm_mmio(KVM_TRACE_MMIO_READ_UNSATISFIED, len, |
e39d200f | 169 | fault_ipa, NULL); |
950324ab AP |
170 | |
171 | ret = kvm_io_bus_read(vcpu, KVM_MMIO_BUS, fault_ipa, len, | |
172 | data_buf); | |
5100f983 | 173 | } |
45e96ea6 | 174 | |
950324ab AP |
175 | /* Now prepare kvm_run for the potential return to userland. */ |
176 | run->mmio.is_write = is_write; | |
177 | run->mmio.phys_addr = fault_ipa; | |
178 | run->mmio.len = len; | |
2113c5f6 | 179 | vcpu->mmio_needed = 1; |
950324ab AP |
180 | |
181 | if (!ret) { | |
182 | /* We handled the access successfully in the kernel. */ | |
83091db9 CD |
183 | if (!is_write) |
184 | memcpy(run->mmio.data, data_buf, len); | |
b19e6892 | 185 | vcpu->stat.mmio_exit_kernel++; |
74cc7e0c | 186 | kvm_handle_mmio_return(vcpu); |
1a89dd91 | 187 | return 1; |
950324ab | 188 | } |
1a89dd91 | 189 | |
83091db9 CD |
190 | if (is_write) |
191 | memcpy(run->mmio.data, data_buf, len); | |
192 | vcpu->stat.mmio_exit_user++; | |
950324ab | 193 | run->exit_reason = KVM_EXIT_MMIO; |
45e96ea6 CD |
194 | return 0; |
195 | } |