1 /*
2 * priv.c - handling privileged instructions
3 *
4 * Copyright IBM Corp. 2008
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/gfp.h>
16 #include <linux/errno.h>
17 #include <asm/current.h>
18 #include <asm/debug.h>
19 #include <asm/ebcdic.h>
20 #include <asm/sysinfo.h>
21 #include "gaccess.h"
22 #include "kvm-s390.h"
23
handle_set_prefix(struct kvm_vcpu * vcpu)24 static int handle_set_prefix(struct kvm_vcpu *vcpu)
25 {
26 int base2 = vcpu->arch.sie_block->ipb >> 28;
27 int disp2 = ((vcpu->arch.sie_block->ipb & 0x0fff0000) >> 16);
28 u64 operand2;
29 u32 address = 0;
30 u8 tmp;
31
32 vcpu->stat.instruction_spx++;
33
34 operand2 = disp2;
35 if (base2)
36 operand2 += vcpu->run->s.regs.gprs[base2];
37
38 /* must be word boundary */
39 if (operand2 & 3) {
40 kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
41 goto out;
42 }
43
44 /* get the value */
45 if (get_guest_u32(vcpu, operand2, &address)) {
46 kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
47 goto out;
48 }
49
50 address = address & 0x7fffe000u;
51
52 /* make sure that the new value is valid memory */
53 if (copy_from_guest_absolute(vcpu, &tmp, address, 1) ||
54 (copy_from_guest_absolute(vcpu, &tmp, address + PAGE_SIZE, 1))) {
55 kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
56 goto out;
57 }
58
59 kvm_s390_set_prefix(vcpu, address);
60
61 VCPU_EVENT(vcpu, 5, "setting prefix to %x", address);
62 out:
63 return 0;
64 }
65
handle_store_prefix(struct kvm_vcpu * vcpu)66 static int handle_store_prefix(struct kvm_vcpu *vcpu)
67 {
68 int base2 = vcpu->arch.sie_block->ipb >> 28;
69 int disp2 = ((vcpu->arch.sie_block->ipb & 0x0fff0000) >> 16);
70 u64 operand2;
71 u32 address;
72
73 vcpu->stat.instruction_stpx++;
74 operand2 = disp2;
75 if (base2)
76 operand2 += vcpu->run->s.regs.gprs[base2];
77
78 /* must be word boundary */
79 if (operand2 & 3) {
80 kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
81 goto out;
82 }
83
84 address = vcpu->arch.sie_block->prefix;
85 address = address & 0x7fffe000u;
86
87 /* get the value */
88 if (put_guest_u32(vcpu, operand2, address)) {
89 kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
90 goto out;
91 }
92
93 VCPU_EVENT(vcpu, 5, "storing prefix to %x", address);
94 out:
95 return 0;
96 }
97
handle_store_cpu_address(struct kvm_vcpu * vcpu)98 static int handle_store_cpu_address(struct kvm_vcpu *vcpu)
99 {
100 int base2 = vcpu->arch.sie_block->ipb >> 28;
101 int disp2 = ((vcpu->arch.sie_block->ipb & 0x0fff0000) >> 16);
102 u64 useraddr;
103 int rc;
104
105 vcpu->stat.instruction_stap++;
106 useraddr = disp2;
107 if (base2)
108 useraddr += vcpu->run->s.regs.gprs[base2];
109
110 if (useraddr & 1) {
111 kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
112 goto out;
113 }
114
115 rc = put_guest_u16(vcpu, useraddr, vcpu->vcpu_id);
116 if (rc == -EFAULT) {
117 kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
118 goto out;
119 }
120
121 VCPU_EVENT(vcpu, 5, "storing cpu address to %llx", useraddr);
122 out:
123 return 0;
124 }
125
handle_skey(struct kvm_vcpu * vcpu)126 static int handle_skey(struct kvm_vcpu *vcpu)
127 {
128 vcpu->stat.instruction_storage_key++;
129 vcpu->arch.sie_block->gpsw.addr -= 4;
130 VCPU_EVENT(vcpu, 4, "%s", "retrying storage key operation");
131 return 0;
132 }
133
handle_stsch(struct kvm_vcpu * vcpu)134 static int handle_stsch(struct kvm_vcpu *vcpu)
135 {
136 vcpu->stat.instruction_stsch++;
137 VCPU_EVENT(vcpu, 4, "%s", "store subchannel - CC3");
138 /* condition code 3 */
139 vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
140 vcpu->arch.sie_block->gpsw.mask |= (3 & 3ul) << 44;
141 return 0;
142 }
143
handle_chsc(struct kvm_vcpu * vcpu)144 static int handle_chsc(struct kvm_vcpu *vcpu)
145 {
146 vcpu->stat.instruction_chsc++;
147 VCPU_EVENT(vcpu, 4, "%s", "channel subsystem call - CC3");
148 /* condition code 3 */
149 vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
150 vcpu->arch.sie_block->gpsw.mask |= (3 & 3ul) << 44;
151 return 0;
152 }
153
handle_stfl(struct kvm_vcpu * vcpu)154 static int handle_stfl(struct kvm_vcpu *vcpu)
155 {
156 unsigned int facility_list;
157 int rc;
158
159 vcpu->stat.instruction_stfl++;
160 /* only pass the facility bits, which we can handle */
161 facility_list = S390_lowcore.stfl_fac_list & 0xff00fff3;
162
163 rc = copy_to_guest(vcpu, offsetof(struct _lowcore, stfl_fac_list),
164 &facility_list, sizeof(facility_list));
165 if (rc == -EFAULT)
166 kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
167 else
168 VCPU_EVENT(vcpu, 5, "store facility list value %x",
169 facility_list);
170 return 0;
171 }
172
handle_stidp(struct kvm_vcpu * vcpu)173 static int handle_stidp(struct kvm_vcpu *vcpu)
174 {
175 int base2 = vcpu->arch.sie_block->ipb >> 28;
176 int disp2 = ((vcpu->arch.sie_block->ipb & 0x0fff0000) >> 16);
177 u64 operand2;
178 int rc;
179
180 vcpu->stat.instruction_stidp++;
181 operand2 = disp2;
182 if (base2)
183 operand2 += vcpu->run->s.regs.gprs[base2];
184
185 if (operand2 & 7) {
186 kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
187 goto out;
188 }
189
190 rc = put_guest_u64(vcpu, operand2, vcpu->arch.stidp_data);
191 if (rc == -EFAULT) {
192 kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
193 goto out;
194 }
195
196 VCPU_EVENT(vcpu, 5, "%s", "store cpu id");
197 out:
198 return 0;
199 }
200
handle_stsi_3_2_2(struct kvm_vcpu * vcpu,struct sysinfo_3_2_2 * mem)201 static void handle_stsi_3_2_2(struct kvm_vcpu *vcpu, struct sysinfo_3_2_2 *mem)
202 {
203 struct kvm_s390_float_interrupt *fi = &vcpu->kvm->arch.float_int;
204 int cpus = 0;
205 int n;
206
207 spin_lock(&fi->lock);
208 for (n = 0; n < KVM_MAX_VCPUS; n++)
209 if (fi->local_int[n])
210 cpus++;
211 spin_unlock(&fi->lock);
212
213 /* deal with other level 3 hypervisors */
214 if (stsi(mem, 3, 2, 2) == -ENOSYS)
215 mem->count = 0;
216 if (mem->count < 8)
217 mem->count++;
218 for (n = mem->count - 1; n > 0 ; n--)
219 memcpy(&mem->vm[n], &mem->vm[n - 1], sizeof(mem->vm[0]));
220
221 mem->vm[0].cpus_total = cpus;
222 mem->vm[0].cpus_configured = cpus;
223 mem->vm[0].cpus_standby = 0;
224 mem->vm[0].cpus_reserved = 0;
225 mem->vm[0].caf = 1000;
226 memcpy(mem->vm[0].name, "KVMguest", 8);
227 ASCEBC(mem->vm[0].name, 8);
228 memcpy(mem->vm[0].cpi, "KVM/Linux ", 16);
229 ASCEBC(mem->vm[0].cpi, 16);
230 }
231
handle_stsi(struct kvm_vcpu * vcpu)232 static int handle_stsi(struct kvm_vcpu *vcpu)
233 {
234 int fc = (vcpu->run->s.regs.gprs[0] & 0xf0000000) >> 28;
235 int sel1 = vcpu->run->s.regs.gprs[0] & 0xff;
236 int sel2 = vcpu->run->s.regs.gprs[1] & 0xffff;
237 int base2 = vcpu->arch.sie_block->ipb >> 28;
238 int disp2 = ((vcpu->arch.sie_block->ipb & 0x0fff0000) >> 16);
239 u64 operand2;
240 unsigned long mem;
241
242 vcpu->stat.instruction_stsi++;
243 VCPU_EVENT(vcpu, 4, "stsi: fc: %x sel1: %x sel2: %x", fc, sel1, sel2);
244
245 operand2 = disp2;
246 if (base2)
247 operand2 += vcpu->run->s.regs.gprs[base2];
248
249 if (operand2 & 0xfff && fc > 0)
250 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
251
252 switch (fc) {
253 case 0:
254 vcpu->run->s.regs.gprs[0] = 3 << 28;
255 vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
256 return 0;
257 case 1: /* same handling for 1 and 2 */
258 case 2:
259 mem = get_zeroed_page(GFP_KERNEL);
260 if (!mem)
261 goto out_fail;
262 if (stsi((void *) mem, fc, sel1, sel2) == -ENOSYS)
263 goto out_mem;
264 break;
265 case 3:
266 if (sel1 != 2 || sel2 != 2)
267 goto out_fail;
268 mem = get_zeroed_page(GFP_KERNEL);
269 if (!mem)
270 goto out_fail;
271 handle_stsi_3_2_2(vcpu, (void *) mem);
272 break;
273 default:
274 goto out_fail;
275 }
276
277 if (copy_to_guest_absolute(vcpu, operand2, (void *) mem, PAGE_SIZE)) {
278 kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
279 goto out_mem;
280 }
281 free_page(mem);
282 vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
283 vcpu->run->s.regs.gprs[0] = 0;
284 return 0;
285 out_mem:
286 free_page(mem);
287 out_fail:
288 /* condition code 3 */
289 vcpu->arch.sie_block->gpsw.mask |= 3ul << 44;
290 return 0;
291 }
292
293 static intercept_handler_t priv_handlers[256] = {
294 [0x02] = handle_stidp,
295 [0x10] = handle_set_prefix,
296 [0x11] = handle_store_prefix,
297 [0x12] = handle_store_cpu_address,
298 [0x29] = handle_skey,
299 [0x2a] = handle_skey,
300 [0x2b] = handle_skey,
301 [0x34] = handle_stsch,
302 [0x5f] = handle_chsc,
303 [0x7d] = handle_stsi,
304 [0xb1] = handle_stfl,
305 };
306
kvm_s390_handle_b2(struct kvm_vcpu * vcpu)307 int kvm_s390_handle_b2(struct kvm_vcpu *vcpu)
308 {
309 intercept_handler_t handler;
310
311 /*
312 * a lot of B2 instructions are priviledged. We first check for
313 * the privileged ones, that we can handle in the kernel. If the
314 * kernel can handle this instruction, we check for the problem
315 * state bit and (a) handle the instruction or (b) send a code 2
316 * program check.
317 * Anything else goes to userspace.*/
318 handler = priv_handlers[vcpu->arch.sie_block->ipa & 0x00ff];
319 if (handler) {
320 if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
321 return kvm_s390_inject_program_int(vcpu,
322 PGM_PRIVILEGED_OPERATION);
323 else
324 return handler(vcpu);
325 }
326 return -EOPNOTSUPP;
327 }
328
handle_tprot(struct kvm_vcpu * vcpu)329 static int handle_tprot(struct kvm_vcpu *vcpu)
330 {
331 int base1 = (vcpu->arch.sie_block->ipb & 0xf0000000) >> 28;
332 int disp1 = (vcpu->arch.sie_block->ipb & 0x0fff0000) >> 16;
333 int base2 = (vcpu->arch.sie_block->ipb & 0xf000) >> 12;
334 int disp2 = vcpu->arch.sie_block->ipb & 0x0fff;
335 u64 address1 = disp1 + base1 ? vcpu->run->s.regs.gprs[base1] : 0;
336 u64 address2 = disp2 + base2 ? vcpu->run->s.regs.gprs[base2] : 0;
337 struct vm_area_struct *vma;
338 unsigned long user_address;
339
340 vcpu->stat.instruction_tprot++;
341
342 /* we only handle the Linux memory detection case:
343 * access key == 0
344 * guest DAT == off
345 * everything else goes to userspace. */
346 if (address2 & 0xf0)
347 return -EOPNOTSUPP;
348 if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_DAT)
349 return -EOPNOTSUPP;
350
351
352 /* we must resolve the address without holding the mmap semaphore.
353 * This is ok since the userspace hypervisor is not supposed to change
354 * the mapping while the guest queries the memory. Otherwise the guest
355 * might crash or get wrong info anyway. */
356 user_address = (unsigned long) __guestaddr_to_user(vcpu, address1);
357
358 down_read(¤t->mm->mmap_sem);
359 vma = find_vma(current->mm, user_address);
360 if (!vma) {
361 up_read(¤t->mm->mmap_sem);
362 return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
363 }
364
365 vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
366 if (!(vma->vm_flags & VM_WRITE) && (vma->vm_flags & VM_READ))
367 vcpu->arch.sie_block->gpsw.mask |= (1ul << 44);
368 if (!(vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_READ))
369 vcpu->arch.sie_block->gpsw.mask |= (2ul << 44);
370
371 up_read(¤t->mm->mmap_sem);
372 return 0;
373 }
374
kvm_s390_handle_e5(struct kvm_vcpu * vcpu)375 int kvm_s390_handle_e5(struct kvm_vcpu *vcpu)
376 {
377 /* For e5xx... instructions we only handle TPROT */
378 if ((vcpu->arch.sie_block->ipa & 0x00ff) == 0x01)
379 return handle_tprot(vcpu);
380 return -EOPNOTSUPP;
381 }
382
383