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1/*
2 * diag.c - handling diagnose instructions
3 *
4 * Copyright IBM Corp. 2008,2011
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License (version 2 only)
8 * as published by the Free Software Foundation.
9 *
10 * Author(s): Carsten Otte <cotte@de.ibm.com>
11 * Christian Borntraeger <borntraeger@de.ibm.com>
12 */
13
14#include <linux/kvm.h>
15#include <linux/kvm_host.h>
16#include "kvm-s390.h"
17
18static int diag_release_pages(struct kvm_vcpu *vcpu)
19{
20 unsigned long start, end;
21 unsigned long prefix = vcpu->arch.sie_block->prefix;
22
23 start = vcpu->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4];
24 end = vcpu->run->s.regs.gprs[vcpu->arch.sie_block->ipa & 0xf] + 4096;
25
26 if (start & ~PAGE_MASK || end & ~PAGE_MASK || start > end
27 || start < 2 * PAGE_SIZE)
28 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
29
30 VCPU_EVENT(vcpu, 5, "diag release pages %lX %lX", start, end);
31 vcpu->stat.diagnose_10++;
32
33 /* we checked for start > end above */
34 if (end < prefix || start >= prefix + 2 * PAGE_SIZE) {
35 gmap_discard(start, end, vcpu->arch.gmap);
36 } else {
37 if (start < prefix)
38 gmap_discard(start, prefix, vcpu->arch.gmap);
39 if (end >= prefix)
40 gmap_discard(prefix + 2 * PAGE_SIZE,
41 end, vcpu->arch.gmap);
42 }
43 return 0;
44}
45
46static int __diag_time_slice_end(struct kvm_vcpu *vcpu)
47{
48 VCPU_EVENT(vcpu, 5, "%s", "diag time slice end");
49 vcpu->stat.diagnose_44++;
50 kvm_vcpu_on_spin(vcpu);
51 return 0;
52}
53
54static int __diag_time_slice_end_directed(struct kvm_vcpu *vcpu)
55{
56 struct kvm *kvm = vcpu->kvm;
57 struct kvm_vcpu *tcpu;
58 int tid;
59 int i;
60
61 tid = vcpu->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4];
62 vcpu->stat.diagnose_9c++;
63 VCPU_EVENT(vcpu, 5, "diag time slice end directed to %d", tid);
64
65 if (tid == vcpu->vcpu_id)
66 return 0;
67
68 kvm_for_each_vcpu(i, tcpu, kvm)
69 if (tcpu->vcpu_id == tid) {
70 kvm_vcpu_yield_to(tcpu);
71 break;
72 }
73
74 return 0;
75}
76
77static int __diag_ipl_functions(struct kvm_vcpu *vcpu)
78{
79 unsigned int reg = vcpu->arch.sie_block->ipa & 0xf;
80 unsigned long subcode = vcpu->run->s.regs.gprs[reg] & 0xffff;
81
82 VCPU_EVENT(vcpu, 5, "diag ipl functions, subcode %lx", subcode);
83 switch (subcode) {
84 case 3:
85 vcpu->run->s390_reset_flags = KVM_S390_RESET_CLEAR;
86 break;
87 case 4:
88 vcpu->run->s390_reset_flags = 0;
89 break;
90 default:
91 return -EOPNOTSUPP;
92 }
93
94 atomic_set_mask(CPUSTAT_STOPPED, &vcpu->arch.sie_block->cpuflags);
95 vcpu->run->s390_reset_flags |= KVM_S390_RESET_SUBSYSTEM;
96 vcpu->run->s390_reset_flags |= KVM_S390_RESET_IPL;
97 vcpu->run->s390_reset_flags |= KVM_S390_RESET_CPU_INIT;
98 vcpu->run->exit_reason = KVM_EXIT_S390_RESET;
99 VCPU_EVENT(vcpu, 3, "requesting userspace resets %llx",
100 vcpu->run->s390_reset_flags);
101 return -EREMOTE;
102}
103
104int kvm_s390_handle_diag(struct kvm_vcpu *vcpu)
105{
106 int code = (vcpu->arch.sie_block->ipb & 0xfff0000) >> 16;
107
108 switch (code) {
109 case 0x10:
110 return diag_release_pages(vcpu);
111 case 0x44:
112 return __diag_time_slice_end(vcpu);
113 case 0x9c:
114 return __diag_time_slice_end_directed(vcpu);
115 case 0x308:
116 return __diag_ipl_functions(vcpu);
117 default:
118 return -EOPNOTSUPP;
119 }
120}
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.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.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.diagnose_44++;
149 kvm_vcpu_on_spin(vcpu, true);
150 return 0;
151}
152
153static int __diag_time_slice_end_directed(struct kvm_vcpu *vcpu)
154{
155 struct kvm_vcpu *tcpu;
156 int tid;
157
158 tid = vcpu->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4];
159 vcpu->stat.diagnose_9c++;
160
161 /* yield to self */
162 if (tid == vcpu->vcpu_id)
163 goto no_yield;
164
165 /* yield to invalid */
166 tcpu = kvm_get_vcpu_by_id(vcpu->kvm, tid);
167 if (!tcpu)
168 goto no_yield;
169
170 /* target already running */
171 if (READ_ONCE(tcpu->cpu) >= 0)
172 goto no_yield;
173
174 if (kvm_vcpu_yield_to(tcpu) <= 0)
175 goto no_yield;
176
177 VCPU_EVENT(vcpu, 5, "diag time slice end directed to %d: done", tid);
178 return 0;
179no_yield:
180 VCPU_EVENT(vcpu, 5, "diag time slice end directed to %d: ignored", tid);
181 vcpu->stat.diagnose_9c_ignored++;
182 return 0;
183}
184
185static int __diag_ipl_functions(struct kvm_vcpu *vcpu)
186{
187 unsigned int reg = vcpu->arch.sie_block->ipa & 0xf;
188 unsigned long subcode = vcpu->run->s.regs.gprs[reg] & 0xffff;
189
190 VCPU_EVENT(vcpu, 3, "diag ipl functions, subcode %lx", subcode);
191 vcpu->stat.diagnose_308++;
192 switch (subcode) {
193 case 3:
194 vcpu->run->s390_reset_flags = KVM_S390_RESET_CLEAR;
195 break;
196 case 4:
197 vcpu->run->s390_reset_flags = 0;
198 break;
199 default:
200 return -EOPNOTSUPP;
201 }
202
203 /*
204 * no need to check the return value of vcpu_stop as it can only have
205 * an error for protvirt, but protvirt means user cpu state
206 */
207 if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm))
208 kvm_s390_vcpu_stop(vcpu);
209 vcpu->run->s390_reset_flags |= KVM_S390_RESET_SUBSYSTEM;
210 vcpu->run->s390_reset_flags |= KVM_S390_RESET_IPL;
211 vcpu->run->s390_reset_flags |= KVM_S390_RESET_CPU_INIT;
212 vcpu->run->exit_reason = KVM_EXIT_S390_RESET;
213 VCPU_EVENT(vcpu, 3, "requesting userspace resets %llx",
214 vcpu->run->s390_reset_flags);
215 trace_kvm_s390_request_resets(vcpu->run->s390_reset_flags);
216 return -EREMOTE;
217}
218
219static int __diag_virtio_hypercall(struct kvm_vcpu *vcpu)
220{
221 int ret;
222
223 vcpu->stat.diagnose_500++;
224 /* No virtio-ccw notification? Get out quickly. */
225 if (!vcpu->kvm->arch.css_support ||
226 (vcpu->run->s.regs.gprs[1] != KVM_S390_VIRTIO_CCW_NOTIFY))
227 return -EOPNOTSUPP;
228
229 VCPU_EVENT(vcpu, 4, "diag 0x500 schid 0x%8.8x queue 0x%x cookie 0x%llx",
230 (u32) vcpu->run->s.regs.gprs[2],
231 (u32) vcpu->run->s.regs.gprs[3],
232 vcpu->run->s.regs.gprs[4]);
233
234 /*
235 * The layout is as follows:
236 * - gpr 2 contains the subchannel id (passed as addr)
237 * - gpr 3 contains the virtqueue index (passed as datamatch)
238 * - gpr 4 contains the index on the bus (optionally)
239 */
240 ret = kvm_io_bus_write_cookie(vcpu, KVM_VIRTIO_CCW_NOTIFY_BUS,
241 vcpu->run->s.regs.gprs[2] & 0xffffffff,
242 8, &vcpu->run->s.regs.gprs[3],
243 vcpu->run->s.regs.gprs[4]);
244
245 /*
246 * Return cookie in gpr 2, but don't overwrite the register if the
247 * diagnose will be handled by userspace.
248 */
249 if (ret != -EOPNOTSUPP)
250 vcpu->run->s.regs.gprs[2] = ret;
251 /* kvm_io_bus_write_cookie returns -EOPNOTSUPP if it found no match. */
252 return ret < 0 ? ret : 0;
253}
254
255int kvm_s390_handle_diag(struct kvm_vcpu *vcpu)
256{
257 int code = kvm_s390_get_base_disp_rs(vcpu, NULL) & 0xffff;
258
259 if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
260 return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
261
262 trace_kvm_s390_handle_diag(vcpu, code);
263 switch (code) {
264 case 0x10:
265 return diag_release_pages(vcpu);
266 case 0x44:
267 return __diag_time_slice_end(vcpu);
268 case 0x9c:
269 return __diag_time_slice_end_directed(vcpu);
270 case 0x258:
271 return __diag_page_ref_service(vcpu);
272 case 0x308:
273 return __diag_ipl_functions(vcpu);
274 case 0x500:
275 return __diag_virtio_hypercall(vcpu);
276 default:
277 vcpu->stat.diagnose_other++;
278 return -EOPNOTSUPP;
279 }
280}