1 /*
2 * 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 <asm/pgalloc.h>
17 #include <asm/virtio-ccw.h>
18 #include "kvm-s390.h"
19 #include "trace.h"
20 #include "trace-s390.h"
21 #include "gaccess.h"
22
diag_release_pages(struct kvm_vcpu * vcpu)23 static int diag_release_pages(struct kvm_vcpu *vcpu)
24 {
25 unsigned long start, end;
26 unsigned long prefix = kvm_s390_get_prefix(vcpu);
27
28 start = vcpu->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4];
29 end = vcpu->run->s.regs.gprs[vcpu->arch.sie_block->ipa & 0xf] + 4096;
30 vcpu->stat.diagnose_10++;
31
32 if (start & ~PAGE_MASK || end & ~PAGE_MASK || start >= end
33 || start < 2 * PAGE_SIZE)
34 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
35
36 VCPU_EVENT(vcpu, 5, "diag release pages %lX %lX", start, end);
37
38 /*
39 * We checked for start >= end above, so lets check for the
40 * fast path (no prefix swap page involved)
41 */
42 if (end <= prefix || start >= prefix + 2 * PAGE_SIZE) {
43 gmap_discard(vcpu->arch.gmap, start, end);
44 } else {
45 /*
46 * This is slow path. gmap_discard will check for start
47 * so lets split this into before prefix, prefix, after
48 * prefix and let gmap_discard make some of these calls
49 * NOPs.
50 */
51 gmap_discard(vcpu->arch.gmap, start, prefix);
52 if (start <= prefix)
53 gmap_discard(vcpu->arch.gmap, 0, 4096);
54 if (end > prefix + 4096)
55 gmap_discard(vcpu->arch.gmap, 4096, 8192);
56 gmap_discard(vcpu->arch.gmap, prefix + 2 * PAGE_SIZE, end);
57 }
58 return 0;
59 }
60
__diag_page_ref_service(struct kvm_vcpu * vcpu)61 static int __diag_page_ref_service(struct kvm_vcpu *vcpu)
62 {
63 struct prs_parm {
64 u16 code;
65 u16 subcode;
66 u16 parm_len;
67 u16 parm_version;
68 u64 token_addr;
69 u64 select_mask;
70 u64 compare_mask;
71 u64 zarch;
72 };
73 struct prs_parm parm;
74 int rc;
75 u16 rx = (vcpu->arch.sie_block->ipa & 0xf0) >> 4;
76 u16 ry = (vcpu->arch.sie_block->ipa & 0x0f);
77
78 VCPU_EVENT(vcpu, 3, "diag page reference parameter block at 0x%llx",
79 vcpu->run->s.regs.gprs[rx]);
80 vcpu->stat.diagnose_258++;
81 if (vcpu->run->s.regs.gprs[rx] & 7)
82 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
83 rc = read_guest(vcpu, vcpu->run->s.regs.gprs[rx], rx, &parm, sizeof(parm));
84 if (rc)
85 return kvm_s390_inject_prog_cond(vcpu, rc);
86 if (parm.parm_version != 2 || parm.parm_len < 5 || parm.code != 0x258)
87 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
88
89 switch (parm.subcode) {
90 case 0: /* TOKEN */
91 VCPU_EVENT(vcpu, 3, "pageref token addr 0x%llx "
92 "select mask 0x%llx compare mask 0x%llx",
93 parm.token_addr, parm.select_mask, parm.compare_mask);
94 if (vcpu->arch.pfault_token != KVM_S390_PFAULT_TOKEN_INVALID) {
95 /*
96 * If the pagefault handshake is already activated,
97 * the token must not be changed. We have to return
98 * decimal 8 instead, as mandated in SC24-6084.
99 */
100 vcpu->run->s.regs.gprs[ry] = 8;
101 return 0;
102 }
103
104 if ((parm.compare_mask & parm.select_mask) != parm.compare_mask ||
105 parm.token_addr & 7 || parm.zarch != 0x8000000000000000ULL)
106 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
107
108 if (kvm_is_error_gpa(vcpu->kvm, parm.token_addr))
109 return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
110
111 vcpu->arch.pfault_token = parm.token_addr;
112 vcpu->arch.pfault_select = parm.select_mask;
113 vcpu->arch.pfault_compare = parm.compare_mask;
114 vcpu->run->s.regs.gprs[ry] = 0;
115 rc = 0;
116 break;
117 case 1: /*
118 * CANCEL
119 * Specification allows to let already pending tokens survive
120 * the cancel, therefore to reduce code complexity, we assume
121 * all outstanding tokens are already pending.
122 */
123 VCPU_EVENT(vcpu, 3, "pageref cancel addr 0x%llx", parm.token_addr);
124 if (parm.token_addr || parm.select_mask ||
125 parm.compare_mask || parm.zarch)
126 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
127
128 vcpu->run->s.regs.gprs[ry] = 0;
129 /*
130 * If the pfault handling was not established or is already
131 * canceled SC24-6084 requests to return decimal 4.
132 */
133 if (vcpu->arch.pfault_token == KVM_S390_PFAULT_TOKEN_INVALID)
134 vcpu->run->s.regs.gprs[ry] = 4;
135 else
136 vcpu->arch.pfault_token = KVM_S390_PFAULT_TOKEN_INVALID;
137
138 rc = 0;
139 break;
140 default:
141 rc = -EOPNOTSUPP;
142 break;
143 }
144
145 return rc;
146 }
147
__diag_time_slice_end(struct kvm_vcpu * vcpu)148 static int __diag_time_slice_end(struct kvm_vcpu *vcpu)
149 {
150 VCPU_EVENT(vcpu, 5, "%s", "diag time slice end");
151 vcpu->stat.diagnose_44++;
152 kvm_vcpu_on_spin(vcpu);
153 return 0;
154 }
155
__diag_time_slice_end_directed(struct kvm_vcpu * vcpu)156 static int __diag_time_slice_end_directed(struct kvm_vcpu *vcpu)
157 {
158 struct kvm *kvm = vcpu->kvm;
159 struct kvm_vcpu *tcpu;
160 int tid;
161 int i;
162
163 tid = vcpu->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4];
164 vcpu->stat.diagnose_9c++;
165 VCPU_EVENT(vcpu, 5, "diag time slice end directed to %d", tid);
166
167 if (tid == vcpu->vcpu_id)
168 return 0;
169
170 kvm_for_each_vcpu(i, tcpu, kvm)
171 if (tcpu->vcpu_id == tid) {
172 kvm_vcpu_yield_to(tcpu);
173 break;
174 }
175
176 return 0;
177 }
178
__diag_ipl_functions(struct kvm_vcpu * vcpu)179 static int __diag_ipl_functions(struct kvm_vcpu *vcpu)
180 {
181 unsigned int reg = vcpu->arch.sie_block->ipa & 0xf;
182 unsigned long subcode = vcpu->run->s.regs.gprs[reg] & 0xffff;
183
184 VCPU_EVENT(vcpu, 3, "diag ipl functions, subcode %lx", subcode);
185 vcpu->stat.diagnose_308++;
186 switch (subcode) {
187 case 3:
188 vcpu->run->s390_reset_flags = KVM_S390_RESET_CLEAR;
189 break;
190 case 4:
191 vcpu->run->s390_reset_flags = 0;
192 break;
193 default:
194 return -EOPNOTSUPP;
195 }
196
197 if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm))
198 kvm_s390_vcpu_stop(vcpu);
199 vcpu->run->s390_reset_flags |= KVM_S390_RESET_SUBSYSTEM;
200 vcpu->run->s390_reset_flags |= KVM_S390_RESET_IPL;
201 vcpu->run->s390_reset_flags |= KVM_S390_RESET_CPU_INIT;
202 vcpu->run->exit_reason = KVM_EXIT_S390_RESET;
203 VCPU_EVENT(vcpu, 3, "requesting userspace resets %llx",
204 vcpu->run->s390_reset_flags);
205 trace_kvm_s390_request_resets(vcpu->run->s390_reset_flags);
206 return -EREMOTE;
207 }
208
__diag_virtio_hypercall(struct kvm_vcpu * vcpu)209 static int __diag_virtio_hypercall(struct kvm_vcpu *vcpu)
210 {
211 int ret;
212
213 vcpu->stat.diagnose_500++;
214 /* No virtio-ccw notification? Get out quickly. */
215 if (!vcpu->kvm->arch.css_support ||
216 (vcpu->run->s.regs.gprs[1] != KVM_S390_VIRTIO_CCW_NOTIFY))
217 return -EOPNOTSUPP;
218
219 /*
220 * The layout is as follows:
221 * - gpr 2 contains the subchannel id (passed as addr)
222 * - gpr 3 contains the virtqueue index (passed as datamatch)
223 * - gpr 4 contains the index on the bus (optionally)
224 */
225 ret = kvm_io_bus_write_cookie(vcpu, KVM_VIRTIO_CCW_NOTIFY_BUS,
226 vcpu->run->s.regs.gprs[2] & 0xffffffff,
227 8, &vcpu->run->s.regs.gprs[3],
228 vcpu->run->s.regs.gprs[4]);
229
230 /*
231 * Return cookie in gpr 2, but don't overwrite the register if the
232 * diagnose will be handled by userspace.
233 */
234 if (ret != -EOPNOTSUPP)
235 vcpu->run->s.regs.gprs[2] = ret;
236 /* kvm_io_bus_write_cookie returns -EOPNOTSUPP if it found no match. */
237 return ret < 0 ? ret : 0;
238 }
239
kvm_s390_handle_diag(struct kvm_vcpu * vcpu)240 int kvm_s390_handle_diag(struct kvm_vcpu *vcpu)
241 {
242 int code = kvm_s390_get_base_disp_rs(vcpu, NULL) & 0xffff;
243
244 if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
245 return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
246
247 trace_kvm_s390_handle_diag(vcpu, code);
248 switch (code) {
249 case 0x10:
250 return diag_release_pages(vcpu);
251 case 0x44:
252 return __diag_time_slice_end(vcpu);
253 case 0x9c:
254 return __diag_time_slice_end_directed(vcpu);
255 case 0x258:
256 return __diag_page_ref_service(vcpu);
257 case 0x308:
258 return __diag_ipl_functions(vcpu);
259 case 0x500:
260 return __diag_virtio_hypercall(vcpu);
261 default:
262 return -EOPNOTSUPP;
263 }
264 }
265