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
diag_release_pages(struct kvm_vcpu * vcpu)21 static 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
__diag_page_ref_service(struct kvm_vcpu * vcpu)59 static 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
__diag_time_slice_end(struct kvm_vcpu * vcpu)146 static 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
__diag_time_slice_end_directed(struct kvm_vcpu * vcpu)154 static 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
__diag_ipl_functions(struct kvm_vcpu * vcpu)172 static 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
__diag_virtio_hypercall(struct kvm_vcpu * vcpu)202 static 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
kvm_s390_handle_diag(struct kvm_vcpu * vcpu)238 int 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 }
264
