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d809aa23 | 1 | // SPDX-License-Identifier: GPL-2.0 |
e28acfea | 2 | /* |
a53c8fab | 3 | * handling diagnose instructions |
e28acfea | 4 | * |
fe28c786 | 5 | * Copyright IBM Corp. 2008, 2020 |
e28acfea | 6 | * |
e28acfea CB |
7 | * Author(s): Carsten Otte <cotte@de.ibm.com> |
8 | * Christian Borntraeger <borntraeger@de.ibm.com> | |
9 | */ | |
10 | ||
11 | #include <linux/kvm.h> | |
12 | #include <linux/kvm_host.h> | |
1e133ab2 | 13 | #include <asm/gmap.h> |
10ccaa1e | 14 | #include <asm/virtio-ccw.h> |
e28acfea | 15 | #include "kvm-s390.h" |
5786fffa | 16 | #include "trace.h" |
ade38c31 | 17 | #include "trace-s390.h" |
3c038e6b | 18 | #include "gaccess.h" |
e28acfea | 19 | |
388186bc CB |
20 | static int diag_release_pages(struct kvm_vcpu *vcpu) |
21 | { | |
22 | unsigned long start, end; | |
fda902cb | 23 | unsigned long prefix = kvm_s390_get_prefix(vcpu); |
388186bc | 24 | |
5a32c1af | 25 | start = vcpu->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4]; |
58cdf5eb | 26 | end = vcpu->run->s.regs.gprs[vcpu->arch.sie_block->ipa & 0xf] + PAGE_SIZE; |
bb000f64 | 27 | vcpu->stat.instruction_diagnose_10++; |
388186bc | 28 | |
f7a960af | 29 | if (start & ~PAGE_MASK || end & ~PAGE_MASK || start >= end |
388186bc CB |
30 | || start < 2 * PAGE_SIZE) |
31 | return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); | |
32 | ||
33 | VCPU_EVENT(vcpu, 5, "diag release pages %lX %lX", start, end); | |
388186bc | 34 | |
f7a960af CB |
35 | /* |
36 | * We checked for start >= end above, so lets check for the | |
37 | * fast path (no prefix swap page involved) | |
38 | */ | |
39 | if (end <= prefix || start >= prefix + 2 * PAGE_SIZE) { | |
6e0a0431 | 40 | gmap_discard(vcpu->arch.gmap, start, end); |
388186bc | 41 | } else { |
f7a960af CB |
42 | /* |
43 | * This is slow path. gmap_discard will check for start | |
44 | * so lets split this into before prefix, prefix, after | |
45 | * prefix and let gmap_discard make some of these calls | |
46 | * NOPs. | |
47 | */ | |
48 | gmap_discard(vcpu->arch.gmap, start, prefix); | |
49 | if (start <= prefix) | |
58cdf5eb HC |
50 | gmap_discard(vcpu->arch.gmap, 0, PAGE_SIZE); |
51 | if (end > prefix + PAGE_SIZE) | |
52 | gmap_discard(vcpu->arch.gmap, PAGE_SIZE, 2 * PAGE_SIZE); | |
f7a960af | 53 | gmap_discard(vcpu->arch.gmap, prefix + 2 * PAGE_SIZE, end); |
388186bc CB |
54 | } |
55 | return 0; | |
56 | } | |
57 | ||
3c038e6b DD |
58 | static int __diag_page_ref_service(struct kvm_vcpu *vcpu) |
59 | { | |
60 | struct prs_parm { | |
61 | u16 code; | |
62 | u16 subcode; | |
63 | u16 parm_len; | |
64 | u16 parm_version; | |
65 | u64 token_addr; | |
66 | u64 select_mask; | |
67 | u64 compare_mask; | |
68 | u64 zarch; | |
69 | }; | |
70 | struct prs_parm parm; | |
71 | int rc; | |
72 | u16 rx = (vcpu->arch.sie_block->ipa & 0xf0) >> 4; | |
73 | u16 ry = (vcpu->arch.sie_block->ipa & 0x0f); | |
3c038e6b | 74 | |
15e8b5da CB |
75 | VCPU_EVENT(vcpu, 3, "diag page reference parameter block at 0x%llx", |
76 | vcpu->run->s.regs.gprs[rx]); | |
bb000f64 | 77 | vcpu->stat.instruction_diagnose_258++; |
3c038e6b DD |
78 | if (vcpu->run->s.regs.gprs[rx] & 7) |
79 | return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); | |
8ae04b8f | 80 | rc = read_guest(vcpu, vcpu->run->s.regs.gprs[rx], rx, &parm, sizeof(parm)); |
81480cc1 HC |
81 | if (rc) |
82 | return kvm_s390_inject_prog_cond(vcpu, rc); | |
3c038e6b DD |
83 | if (parm.parm_version != 2 || parm.parm_len < 5 || parm.code != 0x258) |
84 | return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); | |
85 | ||
86 | switch (parm.subcode) { | |
87 | case 0: /* TOKEN */ | |
ab7090a6 CB |
88 | VCPU_EVENT(vcpu, 3, "pageref token addr 0x%llx " |
89 | "select mask 0x%llx compare mask 0x%llx", | |
90 | parm.token_addr, parm.select_mask, parm.compare_mask); | |
3c038e6b DD |
91 | if (vcpu->arch.pfault_token != KVM_S390_PFAULT_TOKEN_INVALID) { |
92 | /* | |
93 | * If the pagefault handshake is already activated, | |
94 | * the token must not be changed. We have to return | |
95 | * decimal 8 instead, as mandated in SC24-6084. | |
96 | */ | |
97 | vcpu->run->s.regs.gprs[ry] = 8; | |
98 | return 0; | |
99 | } | |
100 | ||
101 | if ((parm.compare_mask & parm.select_mask) != parm.compare_mask || | |
102 | parm.token_addr & 7 || parm.zarch != 0x8000000000000000ULL) | |
103 | return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); | |
104 | ||
81480cc1 | 105 | if (kvm_is_error_gpa(vcpu->kvm, parm.token_addr)) |
3c038e6b DD |
106 | return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING); |
107 | ||
108 | vcpu->arch.pfault_token = parm.token_addr; | |
109 | vcpu->arch.pfault_select = parm.select_mask; | |
110 | vcpu->arch.pfault_compare = parm.compare_mask; | |
111 | vcpu->run->s.regs.gprs[ry] = 0; | |
112 | rc = 0; | |
113 | break; | |
114 | case 1: /* | |
115 | * CANCEL | |
116 | * Specification allows to let already pending tokens survive | |
117 | * the cancel, therefore to reduce code complexity, we assume | |
118 | * all outstanding tokens are already pending. | |
119 | */ | |
ab7090a6 | 120 | VCPU_EVENT(vcpu, 3, "pageref cancel addr 0x%llx", parm.token_addr); |
3c038e6b DD |
121 | if (parm.token_addr || parm.select_mask || |
122 | parm.compare_mask || parm.zarch) | |
123 | return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); | |
124 | ||
125 | vcpu->run->s.regs.gprs[ry] = 0; | |
126 | /* | |
127 | * If the pfault handling was not established or is already | |
128 | * canceled SC24-6084 requests to return decimal 4. | |
129 | */ | |
130 | if (vcpu->arch.pfault_token == KVM_S390_PFAULT_TOKEN_INVALID) | |
131 | vcpu->run->s.regs.gprs[ry] = 4; | |
132 | else | |
133 | vcpu->arch.pfault_token = KVM_S390_PFAULT_TOKEN_INVALID; | |
134 | ||
135 | rc = 0; | |
136 | break; | |
137 | default: | |
138 | rc = -EOPNOTSUPP; | |
139 | break; | |
140 | } | |
141 | ||
142 | return rc; | |
143 | } | |
144 | ||
e28acfea CB |
145 | static int __diag_time_slice_end(struct kvm_vcpu *vcpu) |
146 | { | |
147 | VCPU_EVENT(vcpu, 5, "%s", "diag time slice end"); | |
bb000f64 | 148 | vcpu->stat.instruction_diagnose_44++; |
0546c63d | 149 | kvm_vcpu_on_spin(vcpu, true); |
e28acfea CB |
150 | return 0; |
151 | } | |
152 | ||
87e28a15 PM |
153 | static int forward_cnt; |
154 | static unsigned long cur_slice; | |
155 | ||
156 | static int diag9c_forwarding_overrun(void) | |
157 | { | |
158 | /* Reset the count on a new slice */ | |
159 | if (time_after(jiffies, cur_slice)) { | |
160 | cur_slice = jiffies; | |
161 | forward_cnt = diag9c_forwarding_hz / HZ; | |
162 | } | |
163 | return forward_cnt-- <= 0 ? 1 : 0; | |
164 | } | |
165 | ||
41628d33 KW |
166 | static int __diag_time_slice_end_directed(struct kvm_vcpu *vcpu) |
167 | { | |
41628d33 KW |
168 | struct kvm_vcpu *tcpu; |
169 | int tid; | |
41628d33 KW |
170 | |
171 | tid = vcpu->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4]; | |
bb000f64 | 172 | vcpu->stat.instruction_diagnose_9c++; |
41628d33 | 173 | |
8474e5ca | 174 | /* yield to self */ |
41628d33 | 175 | if (tid == vcpu->vcpu_id) |
8474e5ca | 176 | goto no_yield; |
41628d33 | 177 | |
8474e5ca | 178 | /* yield to invalid */ |
e09fefde | 179 | tcpu = kvm_get_vcpu_by_id(vcpu->kvm, tid); |
8474e5ca CB |
180 | if (!tcpu) |
181 | goto no_yield; | |
182 | ||
87e28a15 PM |
183 | /* target guest VCPU already running */ |
184 | if (READ_ONCE(tcpu->cpu) >= 0) { | |
185 | if (!diag9c_forwarding_hz || diag9c_forwarding_overrun()) | |
186 | goto no_yield; | |
187 | ||
188 | /* target host CPU already running */ | |
189 | if (!vcpu_is_preempted(tcpu->cpu)) | |
190 | goto no_yield; | |
191 | smp_yield_cpu(tcpu->cpu); | |
192 | VCPU_EVENT(vcpu, 5, | |
193 | "diag time slice end directed to %d: yield forwarded", | |
194 | tid); | |
bb000f64 | 195 | vcpu->stat.diag_9c_forward++; |
87e28a15 PM |
196 | return 0; |
197 | } | |
c7b7de63 | 198 | |
8474e5ca CB |
199 | if (kvm_vcpu_yield_to(tcpu) <= 0) |
200 | goto no_yield; | |
201 | ||
202 | VCPU_EVENT(vcpu, 5, "diag time slice end directed to %d: done", tid); | |
203 | return 0; | |
204 | no_yield: | |
205 | VCPU_EVENT(vcpu, 5, "diag time slice end directed to %d: ignored", tid); | |
bb000f64 | 206 | vcpu->stat.diag_9c_ignored++; |
41628d33 KW |
207 | return 0; |
208 | } | |
209 | ||
e28acfea CB |
210 | static int __diag_ipl_functions(struct kvm_vcpu *vcpu) |
211 | { | |
212 | unsigned int reg = vcpu->arch.sie_block->ipa & 0xf; | |
5a32c1af | 213 | unsigned long subcode = vcpu->run->s.regs.gprs[reg] & 0xffff; |
e28acfea | 214 | |
15e8b5da | 215 | VCPU_EVENT(vcpu, 3, "diag ipl functions, subcode %lx", subcode); |
bb000f64 | 216 | vcpu->stat.instruction_diagnose_308++; |
e28acfea CB |
217 | switch (subcode) { |
218 | case 3: | |
219 | vcpu->run->s390_reset_flags = KVM_S390_RESET_CLEAR; | |
220 | break; | |
221 | case 4: | |
222 | vcpu->run->s390_reset_flags = 0; | |
223 | break; | |
224 | default: | |
b8e660b8 | 225 | return -EOPNOTSUPP; |
e28acfea CB |
226 | } |
227 | ||
fe28c786 JF |
228 | /* |
229 | * no need to check the return value of vcpu_stop as it can only have | |
230 | * an error for protvirt, but protvirt means user cpu state | |
231 | */ | |
6352e4d2 DH |
232 | if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm)) |
233 | kvm_s390_vcpu_stop(vcpu); | |
e28acfea CB |
234 | vcpu->run->s390_reset_flags |= KVM_S390_RESET_SUBSYSTEM; |
235 | vcpu->run->s390_reset_flags |= KVM_S390_RESET_IPL; | |
236 | vcpu->run->s390_reset_flags |= KVM_S390_RESET_CPU_INIT; | |
237 | vcpu->run->exit_reason = KVM_EXIT_S390_RESET; | |
33e19115 | 238 | VCPU_EVENT(vcpu, 3, "requesting userspace resets %llx", |
e28acfea | 239 | vcpu->run->s390_reset_flags); |
ade38c31 | 240 | trace_kvm_s390_request_resets(vcpu->run->s390_reset_flags); |
e28acfea CB |
241 | return -EREMOTE; |
242 | } | |
243 | ||
10ccaa1e CH |
244 | static int __diag_virtio_hypercall(struct kvm_vcpu *vcpu) |
245 | { | |
800c1065 | 246 | int ret; |
10ccaa1e | 247 | |
bb000f64 | 248 | vcpu->stat.instruction_diagnose_500++; |
10ccaa1e CH |
249 | /* No virtio-ccw notification? Get out quickly. */ |
250 | if (!vcpu->kvm->arch.css_support || | |
251 | (vcpu->run->s.regs.gprs[1] != KVM_S390_VIRTIO_CCW_NOTIFY)) | |
252 | return -EOPNOTSUPP; | |
253 | ||
1bb78d16 CB |
254 | VCPU_EVENT(vcpu, 4, "diag 0x500 schid 0x%8.8x queue 0x%x cookie 0x%llx", |
255 | (u32) vcpu->run->s.regs.gprs[2], | |
256 | (u32) vcpu->run->s.regs.gprs[3], | |
257 | vcpu->run->s.regs.gprs[4]); | |
258 | ||
10ccaa1e CH |
259 | /* |
260 | * The layout is as follows: | |
261 | * - gpr 2 contains the subchannel id (passed as addr) | |
262 | * - gpr 3 contains the virtqueue index (passed as datamatch) | |
85dfe87e | 263 | * - gpr 4 contains the index on the bus (optionally) |
10ccaa1e | 264 | */ |
e32edf4f | 265 | ret = kvm_io_bus_write_cookie(vcpu, KVM_VIRTIO_CCW_NOTIFY_BUS, |
ff1f3cb4 | 266 | vcpu->run->s.regs.gprs[2] & 0xffffffff, |
85dfe87e CH |
267 | 8, &vcpu->run->s.regs.gprs[3], |
268 | vcpu->run->s.regs.gprs[4]); | |
85dfe87e CH |
269 | |
270 | /* | |
271 | * Return cookie in gpr 2, but don't overwrite the register if the | |
272 | * diagnose will be handled by userspace. | |
273 | */ | |
274 | if (ret != -EOPNOTSUPP) | |
275 | vcpu->run->s.regs.gprs[2] = ret; | |
276 | /* kvm_io_bus_write_cookie returns -EOPNOTSUPP if it found no match. */ | |
10ccaa1e CH |
277 | return ret < 0 ? ret : 0; |
278 | } | |
279 | ||
e28acfea CB |
280 | int kvm_s390_handle_diag(struct kvm_vcpu *vcpu) |
281 | { | |
8ae04b8f | 282 | int code = kvm_s390_get_base_disp_rs(vcpu, NULL) & 0xffff; |
e28acfea | 283 | |
93e1750f TH |
284 | if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE) |
285 | return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP); | |
286 | ||
5786fffa | 287 | trace_kvm_s390_handle_diag(vcpu, code); |
e28acfea | 288 | switch (code) { |
388186bc CB |
289 | case 0x10: |
290 | return diag_release_pages(vcpu); | |
e28acfea CB |
291 | case 0x44: |
292 | return __diag_time_slice_end(vcpu); | |
41628d33 KW |
293 | case 0x9c: |
294 | return __diag_time_slice_end_directed(vcpu); | |
3c038e6b DD |
295 | case 0x258: |
296 | return __diag_page_ref_service(vcpu); | |
e28acfea CB |
297 | case 0x308: |
298 | return __diag_ipl_functions(vcpu); | |
10ccaa1e CH |
299 | case 0x500: |
300 | return __diag_virtio_hypercall(vcpu); | |
e28acfea | 301 | default: |
bb000f64 | 302 | vcpu->stat.instruction_diagnose_other++; |
b8e660b8 | 303 | return -EOPNOTSUPP; |
e28acfea CB |
304 | } |
305 | } |