1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
|
// SPDX-License-Identifier: GPL-2.0
/*
* handling diagnose instructions
*
* Copyright IBM Corp. 2008, 2020
*
* Author(s): Carsten Otte <cotte@de.ibm.com>
* Christian Borntraeger <borntraeger@de.ibm.com>
*/
#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include <asm/gmap.h>
#include <asm/virtio-ccw.h>
#include "kvm-s390.h"
#include "trace.h"
#include "trace-s390.h"
#include "gaccess.h"
static int diag_release_pages(struct kvm_vcpu *vcpu)
{
unsigned long start, end;
unsigned long prefix = kvm_s390_get_prefix(vcpu);
start = vcpu->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4];
end = vcpu->run->s.regs.gprs[vcpu->arch.sie_block->ipa & 0xf] + PAGE_SIZE;
vcpu->stat.diagnose_10++;
if (start & ~PAGE_MASK || end & ~PAGE_MASK || start >= end
|| start < 2 * PAGE_SIZE)
return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
VCPU_EVENT(vcpu, 5, "diag release pages %lX %lX", start, end);
/*
* We checked for start >= end above, so lets check for the
* fast path (no prefix swap page involved)
*/
if (end <= prefix || start >= prefix + 2 * PAGE_SIZE) {
gmap_discard(vcpu->arch.gmap, start, end);
} else {
/*
* This is slow path. gmap_discard will check for start
* so lets split this into before prefix, prefix, after
* prefix and let gmap_discard make some of these calls
* NOPs.
*/
gmap_discard(vcpu->arch.gmap, start, prefix);
if (start <= prefix)
gmap_discard(vcpu->arch.gmap, 0, PAGE_SIZE);
if (end > prefix + PAGE_SIZE)
gmap_discard(vcpu->arch.gmap, PAGE_SIZE, 2 * PAGE_SIZE);
gmap_discard(vcpu->arch.gmap, prefix + 2 * PAGE_SIZE, end);
}
return 0;
}
static int __diag_page_ref_service(struct kvm_vcpu *vcpu)
{
struct prs_parm {
u16 code;
u16 subcode;
u16 parm_len;
u16 parm_version;
u64 token_addr;
u64 select_mask;
u64 compare_mask;
u64 zarch;
};
struct prs_parm parm;
int rc;
u16 rx = (vcpu->arch.sie_block->ipa & 0xf0) >> 4;
u16 ry = (vcpu->arch.sie_block->ipa & 0x0f);
VCPU_EVENT(vcpu, 3, "diag page reference parameter block at 0x%llx",
vcpu->run->s.regs.gprs[rx]);
vcpu->stat.diagnose_258++;
if (vcpu->run->s.regs.gprs[rx] & 7)
return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
rc = read_guest(vcpu, vcpu->run->s.regs.gprs[rx], rx, &parm, sizeof(parm));
if (rc)
return kvm_s390_inject_prog_cond(vcpu, rc);
if (parm.parm_version != 2 || parm.parm_len < 5 || parm.code != 0x258)
return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
switch (parm.subcode) {
case 0: /* TOKEN */
VCPU_EVENT(vcpu, 3, "pageref token addr 0x%llx "
"select mask 0x%llx compare mask 0x%llx",
parm.token_addr, parm.select_mask, parm.compare_mask);
if (vcpu->arch.pfault_token != KVM_S390_PFAULT_TOKEN_INVALID) {
/*
* If the pagefault handshake is already activated,
* the token must not be changed. We have to return
* decimal 8 instead, as mandated in SC24-6084.
*/
vcpu->run->s.regs.gprs[ry] = 8;
return 0;
}
if ((parm.compare_mask & parm.select_mask) != parm.compare_mask ||
parm.token_addr & 7 || parm.zarch != 0x8000000000000000ULL)
return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
if (kvm_is_error_gpa(vcpu->kvm, parm.token_addr))
return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
vcpu->arch.pfault_token = parm.token_addr;
vcpu->arch.pfault_select = parm.select_mask;
vcpu->arch.pfault_compare = parm.compare_mask;
vcpu->run->s.regs.gprs[ry] = 0;
rc = 0;
break;
case 1: /*
* CANCEL
* Specification allows to let already pending tokens survive
* the cancel, therefore to reduce code complexity, we assume
* all outstanding tokens are already pending.
*/
VCPU_EVENT(vcpu, 3, "pageref cancel addr 0x%llx", parm.token_addr);
if (parm.token_addr || parm.select_mask ||
parm.compare_mask || parm.zarch)
return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
vcpu->run->s.regs.gprs[ry] = 0;
/*
* If the pfault handling was not established or is already
* canceled SC24-6084 requests to return decimal 4.
*/
if (vcpu->arch.pfault_token == KVM_S390_PFAULT_TOKEN_INVALID)
vcpu->run->s.regs.gprs[ry] = 4;
else
vcpu->arch.pfault_token = KVM_S390_PFAULT_TOKEN_INVALID;
rc = 0;
break;
default:
rc = -EOPNOTSUPP;
break;
}
return rc;
}
static int __diag_time_slice_end(struct kvm_vcpu *vcpu)
{
VCPU_EVENT(vcpu, 5, "%s", "diag time slice end");
vcpu->stat.diagnose_44++;
kvm_vcpu_on_spin(vcpu, true);
return 0;
}
static int __diag_time_slice_end_directed(struct kvm_vcpu *vcpu)
{
struct kvm_vcpu *tcpu;
int tid;
tid = vcpu->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4];
vcpu->stat.diagnose_9c++;
/* yield to self */
if (tid == vcpu->vcpu_id)
goto no_yield;
/* yield to invalid */
tcpu = kvm_get_vcpu_by_id(vcpu->kvm, tid);
if (!tcpu)
goto no_yield;
/* target already running */
if (READ_ONCE(tcpu->cpu) >= 0)
goto no_yield;
if (kvm_vcpu_yield_to(tcpu) <= 0)
goto no_yield;
VCPU_EVENT(vcpu, 5, "diag time slice end directed to %d: done", tid);
return 0;
no_yield:
VCPU_EVENT(vcpu, 5, "diag time slice end directed to %d: ignored", tid);
vcpu->stat.diagnose_9c_ignored++;
return 0;
}
static int __diag_ipl_functions(struct kvm_vcpu *vcpu)
{
unsigned int reg = vcpu->arch.sie_block->ipa & 0xf;
unsigned long subcode = vcpu->run->s.regs.gprs[reg] & 0xffff;
VCPU_EVENT(vcpu, 3, "diag ipl functions, subcode %lx", subcode);
vcpu->stat.diagnose_308++;
switch (subcode) {
case 3:
vcpu->run->s390_reset_flags = KVM_S390_RESET_CLEAR;
break;
case 4:
vcpu->run->s390_reset_flags = 0;
break;
default:
return -EOPNOTSUPP;
}
/*
* no need to check the return value of vcpu_stop as it can only have
* an error for protvirt, but protvirt means user cpu state
*/
if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm))
kvm_s390_vcpu_stop(vcpu);
vcpu->run->s390_reset_flags |= KVM_S390_RESET_SUBSYSTEM;
vcpu->run->s390_reset_flags |= KVM_S390_RESET_IPL;
vcpu->run->s390_reset_flags |= KVM_S390_RESET_CPU_INIT;
vcpu->run->exit_reason = KVM_EXIT_S390_RESET;
VCPU_EVENT(vcpu, 3, "requesting userspace resets %llx",
vcpu->run->s390_reset_flags);
trace_kvm_s390_request_resets(vcpu->run->s390_reset_flags);
return -EREMOTE;
}
static int __diag_virtio_hypercall(struct kvm_vcpu *vcpu)
{
int ret;
vcpu->stat.diagnose_500++;
/* No virtio-ccw notification? Get out quickly. */
if (!vcpu->kvm->arch.css_support ||
(vcpu->run->s.regs.gprs[1] != KVM_S390_VIRTIO_CCW_NOTIFY))
return -EOPNOTSUPP;
VCPU_EVENT(vcpu, 4, "diag 0x500 schid 0x%8.8x queue 0x%x cookie 0x%llx",
(u32) vcpu->run->s.regs.gprs[2],
(u32) vcpu->run->s.regs.gprs[3],
vcpu->run->s.regs.gprs[4]);
/*
* The layout is as follows:
* - gpr 2 contains the subchannel id (passed as addr)
* - gpr 3 contains the virtqueue index (passed as datamatch)
* - gpr 4 contains the index on the bus (optionally)
*/
ret = kvm_io_bus_write_cookie(vcpu, KVM_VIRTIO_CCW_NOTIFY_BUS,
vcpu->run->s.regs.gprs[2] & 0xffffffff,
8, &vcpu->run->s.regs.gprs[3],
vcpu->run->s.regs.gprs[4]);
/*
* Return cookie in gpr 2, but don't overwrite the register if the
* diagnose will be handled by userspace.
*/
if (ret != -EOPNOTSUPP)
vcpu->run->s.regs.gprs[2] = ret;
/* kvm_io_bus_write_cookie returns -EOPNOTSUPP if it found no match. */
return ret < 0 ? ret : 0;
}
int kvm_s390_handle_diag(struct kvm_vcpu *vcpu)
{
int code = kvm_s390_get_base_disp_rs(vcpu, NULL) & 0xffff;
if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
trace_kvm_s390_handle_diag(vcpu, code);
switch (code) {
case 0x10:
return diag_release_pages(vcpu);
case 0x44:
return __diag_time_slice_end(vcpu);
case 0x9c:
return __diag_time_slice_end_directed(vcpu);
case 0x258:
return __diag_page_ref_service(vcpu);
case 0x308:
return __diag_ipl_functions(vcpu);
case 0x500:
return __diag_virtio_hypercall(vcpu);
default:
vcpu->stat.diagnose_other++;
return -EOPNOTSUPP;
}
}
|
