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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * handling diagnose instructions
4 *
5 * Copyright IBM Corp. 2008, 2020
6 *
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>
13#include <asm/gmap.h>
14#include <asm/virtio-ccw.h>
15#include "kvm-s390.h"
16#include "trace.h"
17#include "trace-s390.h"
18#include "gaccess.h"
19
20static int diag_release_pages(struct kvm_vcpu *vcpu)
21{
22 unsigned long start, end;
23 unsigned long prefix = kvm_s390_get_prefix(vcpu);
24
25 start = vcpu->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4];
26 end = vcpu->run->s.regs.gprs[vcpu->arch.sie_block->ipa & 0xf] + PAGE_SIZE;
27 vcpu->stat.instruction_diagnose_10++;
28
29 if (start & ~PAGE_MASK || end & ~PAGE_MASK || start >= end
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);
34
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) {
40 gmap_discard(vcpu->arch.gmap, start, end);
41 } else {
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)
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);
53 gmap_discard(vcpu->arch.gmap, prefix + 2 * PAGE_SIZE, end);
54 }
55 return 0;
56}
57
58static 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);
74
75 VCPU_EVENT(vcpu, 3, "diag page reference parameter block at 0x%llx",
76 vcpu->run->s.regs.gprs[rx]);
77 vcpu->stat.instruction_diagnose_258++;
78 if (vcpu->run->s.regs.gprs[rx] & 7)
79 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
80 rc = read_guest(vcpu, vcpu->run->s.regs.gprs[rx], rx, &parm, sizeof(parm));
81 if (rc)
82 return kvm_s390_inject_prog_cond(vcpu, rc);
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 */
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);
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
105 if (kvm_is_error_gpa(vcpu->kvm, parm.token_addr))
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 */
120 VCPU_EVENT(vcpu, 3, "pageref cancel addr 0x%llx", parm.token_addr);
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
145static int __diag_time_slice_end(struct kvm_vcpu *vcpu)
146{
147 VCPU_EVENT(vcpu, 5, "%s", "diag time slice end");
148 vcpu->stat.instruction_diagnose_44++;
149 kvm_vcpu_on_spin(vcpu, true);
150 return 0;
151}
152
153static int forward_cnt;
154static unsigned long cur_slice;
155
156static 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
166static int __diag_time_slice_end_directed(struct kvm_vcpu *vcpu)
167{
168 struct kvm_vcpu *tcpu;
169 int tid;
170
171 tid = vcpu->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4];
172 vcpu->stat.instruction_diagnose_9c++;
173
174 /* yield to self */
175 if (tid == vcpu->vcpu_id)
176 goto no_yield;
177
178 /* yield to invalid */
179 tcpu = kvm_get_vcpu_by_id(vcpu->kvm, tid);
180 if (!tcpu)
181 goto no_yield;
182
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);
195 vcpu->stat.diag_9c_forward++;
196 return 0;
197 }
198
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;
204no_yield:
205 VCPU_EVENT(vcpu, 5, "diag time slice end directed to %d: ignored", tid);
206 vcpu->stat.diag_9c_ignored++;
207 return 0;
208}
209
210static int __diag_ipl_functions(struct kvm_vcpu *vcpu)
211{
212 unsigned int reg = vcpu->arch.sie_block->ipa & 0xf;
213 unsigned long subcode = vcpu->run->s.regs.gprs[reg] & 0xffff;
214
215 VCPU_EVENT(vcpu, 3, "diag ipl functions, subcode %lx", subcode);
216 vcpu->stat.instruction_diagnose_308++;
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:
225 return -EOPNOTSUPP;
226 }
227
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 */
232 if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm))
233 kvm_s390_vcpu_stop(vcpu);
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;
238 VCPU_EVENT(vcpu, 3, "requesting userspace resets %llx",
239 vcpu->run->s390_reset_flags);
240 trace_kvm_s390_request_resets(vcpu->run->s390_reset_flags);
241 return -EREMOTE;
242}
243
244static int __diag_virtio_hypercall(struct kvm_vcpu *vcpu)
245{
246 int ret;
247
248 vcpu->stat.instruction_diagnose_500++;
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
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
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)
263 * - gpr 4 contains the index on the bus (optionally)
264 */
265 ret = kvm_io_bus_write_cookie(vcpu, KVM_VIRTIO_CCW_NOTIFY_BUS,
266 vcpu->run->s.regs.gprs[2] & 0xffffffff,
267 8, &vcpu->run->s.regs.gprs[3],
268 vcpu->run->s.regs.gprs[4]);
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. */
277 return ret < 0 ? ret : 0;
278}
279
280int kvm_s390_handle_diag(struct kvm_vcpu *vcpu)
281{
282 int code = kvm_s390_get_base_disp_rs(vcpu, NULL) & 0xffff;
283
284 if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
285 return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
286
287 trace_kvm_s390_handle_diag(vcpu, code);
288 switch (code) {
289 case 0x10:
290 return diag_release_pages(vcpu);
291 case 0x44:
292 return __diag_time_slice_end(vcpu);
293 case 0x9c:
294 return __diag_time_slice_end_directed(vcpu);
295 case 0x258:
296 return __diag_page_ref_service(vcpu);
297 case 0x308:
298 return __diag_ipl_functions(vcpu);
299 case 0x500:
300 return __diag_virtio_hypercall(vcpu);
301 default:
302 vcpu->stat.instruction_diagnose_other++;
303 return -EOPNOTSUPP;
304 }
305}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * handling diagnose instructions
4 *
5 * Copyright IBM Corp. 2008, 2011
6 *
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>
13#include <asm/pgalloc.h>
14#include <asm/gmap.h>
15#include <asm/virtio-ccw.h>
16#include "kvm-s390.h"
17#include "trace.h"
18#include "trace-s390.h"
19#include "gaccess.h"
20
21static int diag_release_pages(struct kvm_vcpu *vcpu)
22{
23 unsigned long start, end;
24 unsigned long prefix = kvm_s390_get_prefix(vcpu);
25
26 start = vcpu->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4];
27 end = vcpu->run->s.regs.gprs[vcpu->arch.sie_block->ipa & 0xf] + PAGE_SIZE;
28 vcpu->stat.diagnose_10++;
29
30 if (start & ~PAGE_MASK || end & ~PAGE_MASK || start >= end
31 || start < 2 * PAGE_SIZE)
32 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
33
34 VCPU_EVENT(vcpu, 5, "diag release pages %lX %lX", start, end);
35
36 /*
37 * We checked for start >= end above, so lets check for the
38 * fast path (no prefix swap page involved)
39 */
40 if (end <= prefix || start >= prefix + 2 * PAGE_SIZE) {
41 gmap_discard(vcpu->arch.gmap, start, end);
42 } else {
43 /*
44 * This is slow path. gmap_discard will check for start
45 * so lets split this into before prefix, prefix, after
46 * prefix and let gmap_discard make some of these calls
47 * NOPs.
48 */
49 gmap_discard(vcpu->arch.gmap, start, prefix);
50 if (start <= prefix)
51 gmap_discard(vcpu->arch.gmap, 0, PAGE_SIZE);
52 if (end > prefix + PAGE_SIZE)
53 gmap_discard(vcpu->arch.gmap, PAGE_SIZE, 2 * PAGE_SIZE);
54 gmap_discard(vcpu->arch.gmap, prefix + 2 * PAGE_SIZE, end);
55 }
56 return 0;
57}
58
59static int __diag_page_ref_service(struct kvm_vcpu *vcpu)
60{
61 struct prs_parm {
62 u16 code;
63 u16 subcode;
64 u16 parm_len;
65 u16 parm_version;
66 u64 token_addr;
67 u64 select_mask;
68 u64 compare_mask;
69 u64 zarch;
70 };
71 struct prs_parm parm;
72 int rc;
73 u16 rx = (vcpu->arch.sie_block->ipa & 0xf0) >> 4;
74 u16 ry = (vcpu->arch.sie_block->ipa & 0x0f);
75
76 VCPU_EVENT(vcpu, 3, "diag page reference parameter block at 0x%llx",
77 vcpu->run->s.regs.gprs[rx]);
78 vcpu->stat.diagnose_258++;
79 if (vcpu->run->s.regs.gprs[rx] & 7)
80 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
81 rc = read_guest(vcpu, vcpu->run->s.regs.gprs[rx], rx, &parm, sizeof(parm));
82 if (rc)
83 return kvm_s390_inject_prog_cond(vcpu, rc);
84 if (parm.parm_version != 2 || parm.parm_len < 5 || parm.code != 0x258)
85 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
86
87 switch (parm.subcode) {
88 case 0: /* TOKEN */
89 VCPU_EVENT(vcpu, 3, "pageref token addr 0x%llx "
90 "select mask 0x%llx compare mask 0x%llx",
91 parm.token_addr, parm.select_mask, parm.compare_mask);
92 if (vcpu->arch.pfault_token != KVM_S390_PFAULT_TOKEN_INVALID) {
93 /*
94 * If the pagefault handshake is already activated,
95 * the token must not be changed. We have to return
96 * decimal 8 instead, as mandated in SC24-6084.
97 */
98 vcpu->run->s.regs.gprs[ry] = 8;
99 return 0;
100 }
101
102 if ((parm.compare_mask & parm.select_mask) != parm.compare_mask ||
103 parm.token_addr & 7 || parm.zarch != 0x8000000000000000ULL)
104 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
105
106 if (kvm_is_error_gpa(vcpu->kvm, parm.token_addr))
107 return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
108
109 vcpu->arch.pfault_token = parm.token_addr;
110 vcpu->arch.pfault_select = parm.select_mask;
111 vcpu->arch.pfault_compare = parm.compare_mask;
112 vcpu->run->s.regs.gprs[ry] = 0;
113 rc = 0;
114 break;
115 case 1: /*
116 * CANCEL
117 * Specification allows to let already pending tokens survive
118 * the cancel, therefore to reduce code complexity, we assume
119 * all outstanding tokens are already pending.
120 */
121 VCPU_EVENT(vcpu, 3, "pageref cancel addr 0x%llx", parm.token_addr);
122 if (parm.token_addr || parm.select_mask ||
123 parm.compare_mask || parm.zarch)
124 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
125
126 vcpu->run->s.regs.gprs[ry] = 0;
127 /*
128 * If the pfault handling was not established or is already
129 * canceled SC24-6084 requests to return decimal 4.
130 */
131 if (vcpu->arch.pfault_token == KVM_S390_PFAULT_TOKEN_INVALID)
132 vcpu->run->s.regs.gprs[ry] = 4;
133 else
134 vcpu->arch.pfault_token = KVM_S390_PFAULT_TOKEN_INVALID;
135
136 rc = 0;
137 break;
138 default:
139 rc = -EOPNOTSUPP;
140 break;
141 }
142
143 return rc;
144}
145
146static int __diag_time_slice_end(struct kvm_vcpu *vcpu)
147{
148 VCPU_EVENT(vcpu, 5, "%s", "diag time slice end");
149 vcpu->stat.diagnose_44++;
150 kvm_vcpu_on_spin(vcpu, true);
151 return 0;
152}
153
154static int __diag_time_slice_end_directed(struct kvm_vcpu *vcpu)
155{
156 struct kvm_vcpu *tcpu;
157 int tid;
158
159 tid = vcpu->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4];
160 vcpu->stat.diagnose_9c++;
161 VCPU_EVENT(vcpu, 5, "diag time slice end directed to %d", tid);
162
163 if (tid == vcpu->vcpu_id)
164 return 0;
165
166 tcpu = kvm_get_vcpu_by_id(vcpu->kvm, tid);
167 if (tcpu)
168 kvm_vcpu_yield_to(tcpu);
169 return 0;
170}
171
172static int __diag_ipl_functions(struct kvm_vcpu *vcpu)
173{
174 unsigned int reg = vcpu->arch.sie_block->ipa & 0xf;
175 unsigned long subcode = vcpu->run->s.regs.gprs[reg] & 0xffff;
176
177 VCPU_EVENT(vcpu, 3, "diag ipl functions, subcode %lx", subcode);
178 vcpu->stat.diagnose_308++;
179 switch (subcode) {
180 case 3:
181 vcpu->run->s390_reset_flags = KVM_S390_RESET_CLEAR;
182 break;
183 case 4:
184 vcpu->run->s390_reset_flags = 0;
185 break;
186 default:
187 return -EOPNOTSUPP;
188 }
189
190 if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm))
191 kvm_s390_vcpu_stop(vcpu);
192 vcpu->run->s390_reset_flags |= KVM_S390_RESET_SUBSYSTEM;
193 vcpu->run->s390_reset_flags |= KVM_S390_RESET_IPL;
194 vcpu->run->s390_reset_flags |= KVM_S390_RESET_CPU_INIT;
195 vcpu->run->exit_reason = KVM_EXIT_S390_RESET;
196 VCPU_EVENT(vcpu, 3, "requesting userspace resets %llx",
197 vcpu->run->s390_reset_flags);
198 trace_kvm_s390_request_resets(vcpu->run->s390_reset_flags);
199 return -EREMOTE;
200}
201
202static int __diag_virtio_hypercall(struct kvm_vcpu *vcpu)
203{
204 int ret;
205
206 vcpu->stat.diagnose_500++;
207 /* No virtio-ccw notification? Get out quickly. */
208 if (!vcpu->kvm->arch.css_support ||
209 (vcpu->run->s.regs.gprs[1] != KVM_S390_VIRTIO_CCW_NOTIFY))
210 return -EOPNOTSUPP;
211
212 VCPU_EVENT(vcpu, 4, "diag 0x500 schid 0x%8.8x queue 0x%x cookie 0x%llx",
213 (u32) vcpu->run->s.regs.gprs[2],
214 (u32) vcpu->run->s.regs.gprs[3],
215 vcpu->run->s.regs.gprs[4]);
216
217 /*
218 * The layout is as follows:
219 * - gpr 2 contains the subchannel id (passed as addr)
220 * - gpr 3 contains the virtqueue index (passed as datamatch)
221 * - gpr 4 contains the index on the bus (optionally)
222 */
223 ret = kvm_io_bus_write_cookie(vcpu, KVM_VIRTIO_CCW_NOTIFY_BUS,
224 vcpu->run->s.regs.gprs[2] & 0xffffffff,
225 8, &vcpu->run->s.regs.gprs[3],
226 vcpu->run->s.regs.gprs[4]);
227
228 /*
229 * Return cookie in gpr 2, but don't overwrite the register if the
230 * diagnose will be handled by userspace.
231 */
232 if (ret != -EOPNOTSUPP)
233 vcpu->run->s.regs.gprs[2] = ret;
234 /* kvm_io_bus_write_cookie returns -EOPNOTSUPP if it found no match. */
235 return ret < 0 ? ret : 0;
236}
237
238int kvm_s390_handle_diag(struct kvm_vcpu *vcpu)
239{
240 int code = kvm_s390_get_base_disp_rs(vcpu, NULL) & 0xffff;
241
242 if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
243 return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
244
245 trace_kvm_s390_handle_diag(vcpu, code);
246 switch (code) {
247 case 0x10:
248 return diag_release_pages(vcpu);
249 case 0x44:
250 return __diag_time_slice_end(vcpu);
251 case 0x9c:
252 return __diag_time_slice_end_directed(vcpu);
253 case 0x258:
254 return __diag_page_ref_service(vcpu);
255 case 0x308:
256 return __diag_ipl_functions(vcpu);
257 case 0x500:
258 return __diag_virtio_hypercall(vcpu);
259 default:
260 vcpu->stat.diagnose_other++;
261 return -EOPNOTSUPP;
262 }
263}