1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * kvm nested virtualization support for s390x
4 *
5 * Copyright IBM Corp. 2016, 2018
6 *
7 * Author(s): David Hildenbrand <dahi@linux.vnet.ibm.com>
8 */
9 #include <linux/vmalloc.h>
10 #include <linux/kvm_host.h>
11 #include <linux/bug.h>
12 #include <linux/list.h>
13 #include <linux/bitmap.h>
14 #include <linux/sched/signal.h>
15 #include <linux/io.h>
16 #include <linux/mman.h>
17
18 #include <asm/gmap.h>
19 #include <asm/mmu_context.h>
20 #include <asm/sclp.h>
21 #include <asm/nmi.h>
22 #include <asm/dis.h>
23 #include <asm/facility.h>
24 #include "kvm-s390.h"
25 #include "gaccess.h"
26
27 enum vsie_page_flags {
28 VSIE_PAGE_IN_USE = 0,
29 };
30
31 struct vsie_page {
32 struct kvm_s390_sie_block scb_s; /* 0x0000 */
33 /*
34 * the backup info for machine check. ensure it's at
35 * the same offset as that in struct sie_page!
36 */
37 struct mcck_volatile_info mcck_info; /* 0x0200 */
38 /*
39 * The pinned original scb. Be aware that other VCPUs can modify
40 * it while we read from it. Values that are used for conditions or
41 * are reused conditionally, should be accessed via READ_ONCE.
42 */
43 struct kvm_s390_sie_block *scb_o; /* 0x0218 */
44 /* the shadow gmap in use by the vsie_page */
45 struct gmap *gmap; /* 0x0220 */
46 /* address of the last reported fault to guest2 */
47 unsigned long fault_addr; /* 0x0228 */
48 /* calculated guest addresses of satellite control blocks */
49 gpa_t sca_gpa; /* 0x0230 */
50 gpa_t itdba_gpa; /* 0x0238 */
51 gpa_t gvrd_gpa; /* 0x0240 */
52 gpa_t riccbd_gpa; /* 0x0248 */
53 gpa_t sdnx_gpa; /* 0x0250 */
54 /*
55 * guest address of the original SCB. Remains set for free vsie
56 * pages, so we can properly look them up in our addr_to_page
57 * radix tree.
58 */
59 gpa_t scb_gpa; /* 0x0258 */
60 /*
61 * Flags: must be set/cleared atomically after the vsie page can be
62 * looked up by other CPUs.
63 */
64 unsigned long flags; /* 0x0260 */
65 __u8 reserved[0x0700 - 0x0268]; /* 0x0268 */
66 struct kvm_s390_crypto_cb crycb; /* 0x0700 */
67 __u8 fac[S390_ARCH_FAC_LIST_SIZE_BYTE]; /* 0x0800 */
68 };
69
70 /**
71 * gmap_shadow_valid() - check if a shadow guest address space matches the
72 * given properties and is still valid
73 * @sg: pointer to the shadow guest address space structure
74 * @asce: ASCE for which the shadow table is requested
75 * @edat_level: edat level to be used for the shadow translation
76 *
77 * Returns 1 if the gmap shadow is still valid and matches the given
78 * properties, the caller can continue using it. Returns 0 otherwise; the
79 * caller has to request a new shadow gmap in this case.
80 */
gmap_shadow_valid(struct gmap * sg,unsigned long asce,int edat_level)81 int gmap_shadow_valid(struct gmap *sg, unsigned long asce, int edat_level)
82 {
83 if (sg->removed)
84 return 0;
85 return sg->orig_asce == asce && sg->edat_level == edat_level;
86 }
87
88 /* trigger a validity icpt for the given scb */
set_validity_icpt(struct kvm_s390_sie_block * scb,__u16 reason_code)89 static int set_validity_icpt(struct kvm_s390_sie_block *scb,
90 __u16 reason_code)
91 {
92 scb->ipa = 0x1000;
93 scb->ipb = ((__u32) reason_code) << 16;
94 scb->icptcode = ICPT_VALIDITY;
95 return 1;
96 }
97
98 /* mark the prefix as unmapped, this will block the VSIE */
prefix_unmapped(struct vsie_page * vsie_page)99 static void prefix_unmapped(struct vsie_page *vsie_page)
100 {
101 atomic_or(PROG_REQUEST, &vsie_page->scb_s.prog20);
102 }
103
104 /* mark the prefix as unmapped and wait until the VSIE has been left */
prefix_unmapped_sync(struct vsie_page * vsie_page)105 static void prefix_unmapped_sync(struct vsie_page *vsie_page)
106 {
107 prefix_unmapped(vsie_page);
108 if (vsie_page->scb_s.prog0c & PROG_IN_SIE)
109 atomic_or(CPUSTAT_STOP_INT, &vsie_page->scb_s.cpuflags);
110 while (vsie_page->scb_s.prog0c & PROG_IN_SIE)
111 cpu_relax();
112 }
113
114 /* mark the prefix as mapped, this will allow the VSIE to run */
prefix_mapped(struct vsie_page * vsie_page)115 static void prefix_mapped(struct vsie_page *vsie_page)
116 {
117 atomic_andnot(PROG_REQUEST, &vsie_page->scb_s.prog20);
118 }
119
120 /* test if the prefix is mapped into the gmap shadow */
prefix_is_mapped(struct vsie_page * vsie_page)121 static int prefix_is_mapped(struct vsie_page *vsie_page)
122 {
123 return !(atomic_read(&vsie_page->scb_s.prog20) & PROG_REQUEST);
124 }
125
126 /* copy the updated intervention request bits into the shadow scb */
update_intervention_requests(struct vsie_page * vsie_page)127 static void update_intervention_requests(struct vsie_page *vsie_page)
128 {
129 const int bits = CPUSTAT_STOP_INT | CPUSTAT_IO_INT | CPUSTAT_EXT_INT;
130 int cpuflags;
131
132 cpuflags = atomic_read(&vsie_page->scb_o->cpuflags);
133 atomic_andnot(bits, &vsie_page->scb_s.cpuflags);
134 atomic_or(cpuflags & bits, &vsie_page->scb_s.cpuflags);
135 }
136
137 /* shadow (filter and validate) the cpuflags */
prepare_cpuflags(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page)138 static int prepare_cpuflags(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
139 {
140 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
141 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
142 int newflags, cpuflags = atomic_read(&scb_o->cpuflags);
143
144 /* we don't allow ESA/390 guests */
145 if (!(cpuflags & CPUSTAT_ZARCH))
146 return set_validity_icpt(scb_s, 0x0001U);
147
148 if (cpuflags & (CPUSTAT_RRF | CPUSTAT_MCDS))
149 return set_validity_icpt(scb_s, 0x0001U);
150 else if (cpuflags & (CPUSTAT_SLSV | CPUSTAT_SLSR))
151 return set_validity_icpt(scb_s, 0x0007U);
152
153 /* intervention requests will be set later */
154 newflags = CPUSTAT_ZARCH;
155 if (cpuflags & CPUSTAT_GED && test_kvm_facility(vcpu->kvm, 8))
156 newflags |= CPUSTAT_GED;
157 if (cpuflags & CPUSTAT_GED2 && test_kvm_facility(vcpu->kvm, 78)) {
158 if (cpuflags & CPUSTAT_GED)
159 return set_validity_icpt(scb_s, 0x0001U);
160 newflags |= CPUSTAT_GED2;
161 }
162 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_GPERE))
163 newflags |= cpuflags & CPUSTAT_P;
164 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_GSLS))
165 newflags |= cpuflags & CPUSTAT_SM;
166 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_IBS))
167 newflags |= cpuflags & CPUSTAT_IBS;
168 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_KSS))
169 newflags |= cpuflags & CPUSTAT_KSS;
170
171 atomic_set(&scb_s->cpuflags, newflags);
172 return 0;
173 }
174 /* Copy to APCB FORMAT1 from APCB FORMAT0 */
setup_apcb10(struct kvm_vcpu * vcpu,struct kvm_s390_apcb1 * apcb_s,unsigned long crycb_gpa,struct kvm_s390_apcb1 * apcb_h)175 static int setup_apcb10(struct kvm_vcpu *vcpu, struct kvm_s390_apcb1 *apcb_s,
176 unsigned long crycb_gpa, struct kvm_s390_apcb1 *apcb_h)
177 {
178 struct kvm_s390_apcb0 tmp;
179 unsigned long apcb_gpa;
180
181 apcb_gpa = crycb_gpa + offsetof(struct kvm_s390_crypto_cb, apcb0);
182
183 if (read_guest_real(vcpu, apcb_gpa, &tmp,
184 sizeof(struct kvm_s390_apcb0)))
185 return -EFAULT;
186
187 apcb_s->apm[0] = apcb_h->apm[0] & tmp.apm[0];
188 apcb_s->aqm[0] = apcb_h->aqm[0] & tmp.aqm[0] & 0xffff000000000000UL;
189 apcb_s->adm[0] = apcb_h->adm[0] & tmp.adm[0] & 0xffff000000000000UL;
190
191 return 0;
192
193 }
194
195 /**
196 * setup_apcb00 - Copy to APCB FORMAT0 from APCB FORMAT0
197 * @vcpu: pointer to the virtual CPU
198 * @apcb_s: pointer to start of apcb in the shadow crycb
199 * @crycb_gpa: guest physical address to start of original guest crycb
200 * @apcb_h: pointer to start of apcb in the guest1
201 *
202 * Returns 0 and -EFAULT on error reading guest apcb
203 */
setup_apcb00(struct kvm_vcpu * vcpu,unsigned long * apcb_s,unsigned long crycb_gpa,unsigned long * apcb_h)204 static int setup_apcb00(struct kvm_vcpu *vcpu, unsigned long *apcb_s,
205 unsigned long crycb_gpa, unsigned long *apcb_h)
206 {
207 unsigned long apcb_gpa;
208
209 apcb_gpa = crycb_gpa + offsetof(struct kvm_s390_crypto_cb, apcb0);
210
211 if (read_guest_real(vcpu, apcb_gpa, apcb_s,
212 sizeof(struct kvm_s390_apcb0)))
213 return -EFAULT;
214
215 bitmap_and(apcb_s, apcb_s, apcb_h,
216 BITS_PER_BYTE * sizeof(struct kvm_s390_apcb0));
217
218 return 0;
219 }
220
221 /**
222 * setup_apcb11 - Copy the FORMAT1 APCB from the guest to the shadow CRYCB
223 * @vcpu: pointer to the virtual CPU
224 * @apcb_s: pointer to start of apcb in the shadow crycb
225 * @crycb_gpa: guest physical address to start of original guest crycb
226 * @apcb_h: pointer to start of apcb in the host
227 *
228 * Returns 0 and -EFAULT on error reading guest apcb
229 */
setup_apcb11(struct kvm_vcpu * vcpu,unsigned long * apcb_s,unsigned long crycb_gpa,unsigned long * apcb_h)230 static int setup_apcb11(struct kvm_vcpu *vcpu, unsigned long *apcb_s,
231 unsigned long crycb_gpa,
232 unsigned long *apcb_h)
233 {
234 unsigned long apcb_gpa;
235
236 apcb_gpa = crycb_gpa + offsetof(struct kvm_s390_crypto_cb, apcb1);
237
238 if (read_guest_real(vcpu, apcb_gpa, apcb_s,
239 sizeof(struct kvm_s390_apcb1)))
240 return -EFAULT;
241
242 bitmap_and(apcb_s, apcb_s, apcb_h,
243 BITS_PER_BYTE * sizeof(struct kvm_s390_apcb1));
244
245 return 0;
246 }
247
248 /**
249 * setup_apcb - Create a shadow copy of the apcb.
250 * @vcpu: pointer to the virtual CPU
251 * @crycb_s: pointer to shadow crycb
252 * @crycb_gpa: guest physical address of original guest crycb
253 * @crycb_h: pointer to the host crycb
254 * @fmt_o: format of the original guest crycb.
255 * @fmt_h: format of the host crycb.
256 *
257 * Checks the compatibility between the guest and host crycb and calls the
258 * appropriate copy function.
259 *
260 * Return 0 or an error number if the guest and host crycb are incompatible.
261 */
setup_apcb(struct kvm_vcpu * vcpu,struct kvm_s390_crypto_cb * crycb_s,const u32 crycb_gpa,struct kvm_s390_crypto_cb * crycb_h,int fmt_o,int fmt_h)262 static int setup_apcb(struct kvm_vcpu *vcpu, struct kvm_s390_crypto_cb *crycb_s,
263 const u32 crycb_gpa,
264 struct kvm_s390_crypto_cb *crycb_h,
265 int fmt_o, int fmt_h)
266 {
267 switch (fmt_o) {
268 case CRYCB_FORMAT2:
269 if ((crycb_gpa & PAGE_MASK) != ((crycb_gpa + 256) & PAGE_MASK))
270 return -EACCES;
271 if (fmt_h != CRYCB_FORMAT2)
272 return -EINVAL;
273 return setup_apcb11(vcpu, (unsigned long *)&crycb_s->apcb1,
274 crycb_gpa,
275 (unsigned long *)&crycb_h->apcb1);
276 case CRYCB_FORMAT1:
277 switch (fmt_h) {
278 case CRYCB_FORMAT2:
279 return setup_apcb10(vcpu, &crycb_s->apcb1,
280 crycb_gpa,
281 &crycb_h->apcb1);
282 case CRYCB_FORMAT1:
283 return setup_apcb00(vcpu,
284 (unsigned long *) &crycb_s->apcb0,
285 crycb_gpa,
286 (unsigned long *) &crycb_h->apcb0);
287 }
288 break;
289 case CRYCB_FORMAT0:
290 if ((crycb_gpa & PAGE_MASK) != ((crycb_gpa + 32) & PAGE_MASK))
291 return -EACCES;
292
293 switch (fmt_h) {
294 case CRYCB_FORMAT2:
295 return setup_apcb10(vcpu, &crycb_s->apcb1,
296 crycb_gpa,
297 &crycb_h->apcb1);
298 case CRYCB_FORMAT1:
299 case CRYCB_FORMAT0:
300 return setup_apcb00(vcpu,
301 (unsigned long *) &crycb_s->apcb0,
302 crycb_gpa,
303 (unsigned long *) &crycb_h->apcb0);
304 }
305 }
306 return -EINVAL;
307 }
308
309 /**
310 * shadow_crycb - Create a shadow copy of the crycb block
311 * @vcpu: a pointer to the virtual CPU
312 * @vsie_page: a pointer to internal date used for the vSIE
313 *
314 * Create a shadow copy of the crycb block and setup key wrapping, if
315 * requested for guest 3 and enabled for guest 2.
316 *
317 * We accept format-1 or format-2, but we convert format-1 into format-2
318 * in the shadow CRYCB.
319 * Using format-2 enables the firmware to choose the right format when
320 * scheduling the SIE.
321 * There is nothing to do for format-0.
322 *
323 * This function centralize the issuing of set_validity_icpt() for all
324 * the subfunctions working on the crycb.
325 *
326 * Returns: - 0 if shadowed or nothing to do
327 * - > 0 if control has to be given to guest 2
328 */
shadow_crycb(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page)329 static int shadow_crycb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
330 {
331 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
332 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
333 const uint32_t crycbd_o = READ_ONCE(scb_o->crycbd);
334 const u32 crycb_addr = crycbd_o & 0x7ffffff8U;
335 unsigned long *b1, *b2;
336 u8 ecb3_flags;
337 u32 ecd_flags;
338 int apie_h;
339 int apie_s;
340 int key_msk = test_kvm_facility(vcpu->kvm, 76);
341 int fmt_o = crycbd_o & CRYCB_FORMAT_MASK;
342 int fmt_h = vcpu->arch.sie_block->crycbd & CRYCB_FORMAT_MASK;
343 int ret = 0;
344
345 scb_s->crycbd = 0;
346
347 apie_h = vcpu->arch.sie_block->eca & ECA_APIE;
348 apie_s = apie_h & scb_o->eca;
349 if (!apie_s && (!key_msk || (fmt_o == CRYCB_FORMAT0)))
350 return 0;
351
352 if (!crycb_addr)
353 return set_validity_icpt(scb_s, 0x0039U);
354
355 if (fmt_o == CRYCB_FORMAT1)
356 if ((crycb_addr & PAGE_MASK) !=
357 ((crycb_addr + 128) & PAGE_MASK))
358 return set_validity_icpt(scb_s, 0x003CU);
359
360 if (apie_s) {
361 ret = setup_apcb(vcpu, &vsie_page->crycb, crycb_addr,
362 vcpu->kvm->arch.crypto.crycb,
363 fmt_o, fmt_h);
364 if (ret)
365 goto end;
366 scb_s->eca |= scb_o->eca & ECA_APIE;
367 }
368
369 /* we may only allow it if enabled for guest 2 */
370 ecb3_flags = scb_o->ecb3 & vcpu->arch.sie_block->ecb3 &
371 (ECB3_AES | ECB3_DEA);
372 ecd_flags = scb_o->ecd & vcpu->arch.sie_block->ecd &
373 (ECD_ECC | ECD_HMAC);
374 if (!ecb3_flags && !ecd_flags)
375 goto end;
376
377 /* copy only the wrapping keys */
378 if (read_guest_real(vcpu, crycb_addr + 72,
379 vsie_page->crycb.dea_wrapping_key_mask, 56))
380 return set_validity_icpt(scb_s, 0x0035U);
381
382 scb_s->ecb3 |= ecb3_flags;
383 scb_s->ecd |= ecd_flags;
384
385 /* xor both blocks in one run */
386 b1 = (unsigned long *) vsie_page->crycb.dea_wrapping_key_mask;
387 b2 = (unsigned long *)
388 vcpu->kvm->arch.crypto.crycb->dea_wrapping_key_mask;
389 /* as 56%8 == 0, bitmap_xor won't overwrite any data */
390 bitmap_xor(b1, b1, b2, BITS_PER_BYTE * 56);
391 end:
392 switch (ret) {
393 case -EINVAL:
394 return set_validity_icpt(scb_s, 0x0022U);
395 case -EFAULT:
396 return set_validity_icpt(scb_s, 0x0035U);
397 case -EACCES:
398 return set_validity_icpt(scb_s, 0x003CU);
399 }
400 scb_s->crycbd = (u32)virt_to_phys(&vsie_page->crycb) | CRYCB_FORMAT2;
401 return 0;
402 }
403
404 /* shadow (round up/down) the ibc to avoid validity icpt */
prepare_ibc(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page)405 static void prepare_ibc(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
406 {
407 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
408 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
409 /* READ_ONCE does not work on bitfields - use a temporary variable */
410 const uint32_t __new_ibc = scb_o->ibc;
411 const uint32_t new_ibc = READ_ONCE(__new_ibc) & 0x0fffU;
412 __u64 min_ibc = (sclp.ibc >> 16) & 0x0fffU;
413
414 scb_s->ibc = 0;
415 /* ibc installed in g2 and requested for g3 */
416 if (vcpu->kvm->arch.model.ibc && new_ibc) {
417 scb_s->ibc = new_ibc;
418 /* takte care of the minimum ibc level of the machine */
419 if (scb_s->ibc < min_ibc)
420 scb_s->ibc = min_ibc;
421 /* take care of the maximum ibc level set for the guest */
422 if (scb_s->ibc > vcpu->kvm->arch.model.ibc)
423 scb_s->ibc = vcpu->kvm->arch.model.ibc;
424 }
425 }
426
427 /* unshadow the scb, copying parameters back to the real scb */
unshadow_scb(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page)428 static void unshadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
429 {
430 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
431 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
432
433 /* interception */
434 scb_o->icptcode = scb_s->icptcode;
435 scb_o->icptstatus = scb_s->icptstatus;
436 scb_o->ipa = scb_s->ipa;
437 scb_o->ipb = scb_s->ipb;
438 scb_o->gbea = scb_s->gbea;
439
440 /* timer */
441 scb_o->cputm = scb_s->cputm;
442 scb_o->ckc = scb_s->ckc;
443 scb_o->todpr = scb_s->todpr;
444
445 /* guest state */
446 scb_o->gpsw = scb_s->gpsw;
447 scb_o->gg14 = scb_s->gg14;
448 scb_o->gg15 = scb_s->gg15;
449 memcpy(scb_o->gcr, scb_s->gcr, 128);
450 scb_o->pp = scb_s->pp;
451
452 /* branch prediction */
453 if (test_kvm_facility(vcpu->kvm, 82)) {
454 scb_o->fpf &= ~FPF_BPBC;
455 scb_o->fpf |= scb_s->fpf & FPF_BPBC;
456 }
457
458 /* interrupt intercept */
459 switch (scb_s->icptcode) {
460 case ICPT_PROGI:
461 case ICPT_INSTPROGI:
462 case ICPT_EXTINT:
463 memcpy((void *)((u64)scb_o + 0xc0),
464 (void *)((u64)scb_s + 0xc0), 0xf0 - 0xc0);
465 break;
466 }
467
468 if (scb_s->ihcpu != 0xffffU)
469 scb_o->ihcpu = scb_s->ihcpu;
470 }
471
472 /*
473 * Setup the shadow scb by copying and checking the relevant parts of the g2
474 * provided scb.
475 *
476 * Returns: - 0 if the scb has been shadowed
477 * - > 0 if control has to be given to guest 2
478 */
shadow_scb(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page)479 static int shadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
480 {
481 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
482 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
483 /* READ_ONCE does not work on bitfields - use a temporary variable */
484 const uint32_t __new_prefix = scb_o->prefix;
485 const uint32_t new_prefix = READ_ONCE(__new_prefix);
486 const bool wants_tx = READ_ONCE(scb_o->ecb) & ECB_TE;
487 bool had_tx = scb_s->ecb & ECB_TE;
488 unsigned long new_mso = 0;
489 int rc;
490
491 /* make sure we don't have any leftovers when reusing the scb */
492 scb_s->icptcode = 0;
493 scb_s->eca = 0;
494 scb_s->ecb = 0;
495 scb_s->ecb2 = 0;
496 scb_s->ecb3 = 0;
497 scb_s->ecd = 0;
498 scb_s->fac = 0;
499 scb_s->fpf = 0;
500
501 rc = prepare_cpuflags(vcpu, vsie_page);
502 if (rc)
503 goto out;
504
505 /* timer */
506 scb_s->cputm = scb_o->cputm;
507 scb_s->ckc = scb_o->ckc;
508 scb_s->todpr = scb_o->todpr;
509 scb_s->epoch = scb_o->epoch;
510
511 /* guest state */
512 scb_s->gpsw = scb_o->gpsw;
513 scb_s->gg14 = scb_o->gg14;
514 scb_s->gg15 = scb_o->gg15;
515 memcpy(scb_s->gcr, scb_o->gcr, 128);
516 scb_s->pp = scb_o->pp;
517
518 /* interception / execution handling */
519 scb_s->gbea = scb_o->gbea;
520 scb_s->lctl = scb_o->lctl;
521 scb_s->svcc = scb_o->svcc;
522 scb_s->ictl = scb_o->ictl;
523 /*
524 * SKEY handling functions can't deal with false setting of PTE invalid
525 * bits. Therefore we cannot provide interpretation and would later
526 * have to provide own emulation handlers.
527 */
528 if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_KSS))
529 scb_s->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE;
530
531 scb_s->icpua = scb_o->icpua;
532
533 if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_SM))
534 new_mso = READ_ONCE(scb_o->mso) & 0xfffffffffff00000UL;
535 /* if the hva of the prefix changes, we have to remap the prefix */
536 if (scb_s->mso != new_mso || scb_s->prefix != new_prefix)
537 prefix_unmapped(vsie_page);
538 /* SIE will do mso/msl validity and exception checks for us */
539 scb_s->msl = scb_o->msl & 0xfffffffffff00000UL;
540 scb_s->mso = new_mso;
541 scb_s->prefix = new_prefix;
542
543 /* We have to definitely flush the tlb if this scb never ran */
544 if (scb_s->ihcpu != 0xffffU)
545 scb_s->ihcpu = scb_o->ihcpu;
546
547 /* MVPG and Protection Exception Interpretation are always available */
548 scb_s->eca |= scb_o->eca & (ECA_MVPGI | ECA_PROTEXCI);
549 /* Host-protection-interruption introduced with ESOP */
550 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_ESOP))
551 scb_s->ecb |= scb_o->ecb & ECB_HOSTPROTINT;
552 /*
553 * CPU Topology
554 * This facility only uses the utility field of the SCA and none of
555 * the cpu entries that are problematic with the other interpretation
556 * facilities so we can pass it through
557 */
558 if (test_kvm_facility(vcpu->kvm, 11))
559 scb_s->ecb |= scb_o->ecb & ECB_PTF;
560 /* transactional execution */
561 if (test_kvm_facility(vcpu->kvm, 73) && wants_tx) {
562 /* remap the prefix is tx is toggled on */
563 if (!had_tx)
564 prefix_unmapped(vsie_page);
565 scb_s->ecb |= ECB_TE;
566 }
567 /* specification exception interpretation */
568 scb_s->ecb |= scb_o->ecb & ECB_SPECI;
569 /* branch prediction */
570 if (test_kvm_facility(vcpu->kvm, 82))
571 scb_s->fpf |= scb_o->fpf & FPF_BPBC;
572 /* SIMD */
573 if (test_kvm_facility(vcpu->kvm, 129)) {
574 scb_s->eca |= scb_o->eca & ECA_VX;
575 scb_s->ecd |= scb_o->ecd & ECD_HOSTREGMGMT;
576 }
577 /* Run-time-Instrumentation */
578 if (test_kvm_facility(vcpu->kvm, 64))
579 scb_s->ecb3 |= scb_o->ecb3 & ECB3_RI;
580 /* Instruction Execution Prevention */
581 if (test_kvm_facility(vcpu->kvm, 130))
582 scb_s->ecb2 |= scb_o->ecb2 & ECB2_IEP;
583 /* Guarded Storage */
584 if (test_kvm_facility(vcpu->kvm, 133)) {
585 scb_s->ecb |= scb_o->ecb & ECB_GS;
586 scb_s->ecd |= scb_o->ecd & ECD_HOSTREGMGMT;
587 }
588 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_SIIF))
589 scb_s->eca |= scb_o->eca & ECA_SII;
590 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_IB))
591 scb_s->eca |= scb_o->eca & ECA_IB;
592 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_CEI))
593 scb_s->eca |= scb_o->eca & ECA_CEI;
594 /* Epoch Extension */
595 if (test_kvm_facility(vcpu->kvm, 139)) {
596 scb_s->ecd |= scb_o->ecd & ECD_MEF;
597 scb_s->epdx = scb_o->epdx;
598 }
599
600 /* etoken */
601 if (test_kvm_facility(vcpu->kvm, 156))
602 scb_s->ecd |= scb_o->ecd & ECD_ETOKENF;
603
604 scb_s->hpid = HPID_VSIE;
605 scb_s->cpnc = scb_o->cpnc;
606
607 prepare_ibc(vcpu, vsie_page);
608 rc = shadow_crycb(vcpu, vsie_page);
609 out:
610 if (rc)
611 unshadow_scb(vcpu, vsie_page);
612 return rc;
613 }
614
kvm_s390_vsie_gmap_notifier(struct gmap * gmap,unsigned long start,unsigned long end)615 void kvm_s390_vsie_gmap_notifier(struct gmap *gmap, unsigned long start,
616 unsigned long end)
617 {
618 struct kvm *kvm = gmap->private;
619 struct vsie_page *cur;
620 unsigned long prefix;
621 int i;
622
623 if (!gmap_is_shadow(gmap))
624 return;
625 /*
626 * Only new shadow blocks are added to the list during runtime,
627 * therefore we can safely reference them all the time.
628 */
629 for (i = 0; i < kvm->arch.vsie.page_count; i++) {
630 cur = READ_ONCE(kvm->arch.vsie.pages[i]);
631 if (!cur)
632 continue;
633 if (READ_ONCE(cur->gmap) != gmap)
634 continue;
635 prefix = cur->scb_s.prefix << GUEST_PREFIX_SHIFT;
636 /* with mso/msl, the prefix lies at an offset */
637 prefix += cur->scb_s.mso;
638 if (prefix <= end && start <= prefix + 2 * PAGE_SIZE - 1)
639 prefix_unmapped_sync(cur);
640 }
641 }
642
643 /*
644 * Map the first prefix page and if tx is enabled also the second prefix page.
645 *
646 * The prefix will be protected, a gmap notifier will inform about unmaps.
647 * The shadow scb must not be executed until the prefix is remapped, this is
648 * guaranteed by properly handling PROG_REQUEST.
649 *
650 * Returns: - 0 on if successfully mapped or already mapped
651 * - > 0 if control has to be given to guest 2
652 * - -EAGAIN if the caller can retry immediately
653 * - -ENOMEM if out of memory
654 */
map_prefix(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page)655 static int map_prefix(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
656 {
657 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
658 u64 prefix = scb_s->prefix << GUEST_PREFIX_SHIFT;
659 int rc;
660
661 if (prefix_is_mapped(vsie_page))
662 return 0;
663
664 /* mark it as mapped so we can catch any concurrent unmappers */
665 prefix_mapped(vsie_page);
666
667 /* with mso/msl, the prefix lies at offset *mso* */
668 prefix += scb_s->mso;
669
670 rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, prefix, NULL);
671 if (!rc && (scb_s->ecb & ECB_TE))
672 rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap,
673 prefix + PAGE_SIZE, NULL);
674 /*
675 * We don't have to mprotect, we will be called for all unshadows.
676 * SIE will detect if protection applies and trigger a validity.
677 */
678 if (rc)
679 prefix_unmapped(vsie_page);
680 if (rc > 0 || rc == -EFAULT)
681 rc = set_validity_icpt(scb_s, 0x0037U);
682 return rc;
683 }
684
685 /*
686 * Pin the guest page given by gpa and set hpa to the pinned host address.
687 * Will always be pinned writable.
688 *
689 * Returns: - 0 on success
690 * - -EINVAL if the gpa is not valid guest storage
691 */
pin_guest_page(struct kvm * kvm,gpa_t gpa,hpa_t * hpa)692 static int pin_guest_page(struct kvm *kvm, gpa_t gpa, hpa_t *hpa)
693 {
694 struct page *page;
695
696 page = gfn_to_page(kvm, gpa_to_gfn(gpa));
697 if (!page)
698 return -EINVAL;
699 *hpa = (hpa_t)page_to_phys(page) + (gpa & ~PAGE_MASK);
700 return 0;
701 }
702
703 /* Unpins a page previously pinned via pin_guest_page, marking it as dirty. */
unpin_guest_page(struct kvm * kvm,gpa_t gpa,hpa_t hpa)704 static void unpin_guest_page(struct kvm *kvm, gpa_t gpa, hpa_t hpa)
705 {
706 kvm_release_page_dirty(pfn_to_page(hpa >> PAGE_SHIFT));
707 /* mark the page always as dirty for migration */
708 mark_page_dirty(kvm, gpa_to_gfn(gpa));
709 }
710
711 /* unpin all blocks previously pinned by pin_blocks(), marking them dirty */
unpin_blocks(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page)712 static void unpin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
713 {
714 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
715 hpa_t hpa;
716
717 hpa = (u64) scb_s->scaoh << 32 | scb_s->scaol;
718 if (hpa) {
719 unpin_guest_page(vcpu->kvm, vsie_page->sca_gpa, hpa);
720 vsie_page->sca_gpa = 0;
721 scb_s->scaol = 0;
722 scb_s->scaoh = 0;
723 }
724
725 hpa = scb_s->itdba;
726 if (hpa) {
727 unpin_guest_page(vcpu->kvm, vsie_page->itdba_gpa, hpa);
728 vsie_page->itdba_gpa = 0;
729 scb_s->itdba = 0;
730 }
731
732 hpa = scb_s->gvrd;
733 if (hpa) {
734 unpin_guest_page(vcpu->kvm, vsie_page->gvrd_gpa, hpa);
735 vsie_page->gvrd_gpa = 0;
736 scb_s->gvrd = 0;
737 }
738
739 hpa = scb_s->riccbd;
740 if (hpa) {
741 unpin_guest_page(vcpu->kvm, vsie_page->riccbd_gpa, hpa);
742 vsie_page->riccbd_gpa = 0;
743 scb_s->riccbd = 0;
744 }
745
746 hpa = scb_s->sdnxo;
747 if (hpa) {
748 unpin_guest_page(vcpu->kvm, vsie_page->sdnx_gpa, hpa);
749 vsie_page->sdnx_gpa = 0;
750 scb_s->sdnxo = 0;
751 }
752 }
753
754 /*
755 * Instead of shadowing some blocks, we can simply forward them because the
756 * addresses in the scb are 64 bit long.
757 *
758 * This works as long as the data lies in one page. If blocks ever exceed one
759 * page, we have to fall back to shadowing.
760 *
761 * As we reuse the sca, the vcpu pointers contained in it are invalid. We must
762 * therefore not enable any facilities that access these pointers (e.g. SIGPIF).
763 *
764 * Returns: - 0 if all blocks were pinned.
765 * - > 0 if control has to be given to guest 2
766 * - -ENOMEM if out of memory
767 */
pin_blocks(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page)768 static int pin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
769 {
770 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
771 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
772 hpa_t hpa;
773 gpa_t gpa;
774 int rc = 0;
775
776 gpa = READ_ONCE(scb_o->scaol) & ~0xfUL;
777 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_64BSCAO))
778 gpa |= (u64) READ_ONCE(scb_o->scaoh) << 32;
779 if (gpa) {
780 if (gpa < 2 * PAGE_SIZE)
781 rc = set_validity_icpt(scb_s, 0x0038U);
782 else if ((gpa & ~0x1fffUL) == kvm_s390_get_prefix(vcpu))
783 rc = set_validity_icpt(scb_s, 0x0011U);
784 else if ((gpa & PAGE_MASK) !=
785 ((gpa + sizeof(struct bsca_block) - 1) & PAGE_MASK))
786 rc = set_validity_icpt(scb_s, 0x003bU);
787 if (!rc) {
788 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
789 if (rc)
790 rc = set_validity_icpt(scb_s, 0x0034U);
791 }
792 if (rc)
793 goto unpin;
794 vsie_page->sca_gpa = gpa;
795 scb_s->scaoh = (u32)((u64)hpa >> 32);
796 scb_s->scaol = (u32)(u64)hpa;
797 }
798
799 gpa = READ_ONCE(scb_o->itdba) & ~0xffUL;
800 if (gpa && (scb_s->ecb & ECB_TE)) {
801 if (gpa < 2 * PAGE_SIZE) {
802 rc = set_validity_icpt(scb_s, 0x0080U);
803 goto unpin;
804 }
805 /* 256 bytes cannot cross page boundaries */
806 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
807 if (rc) {
808 rc = set_validity_icpt(scb_s, 0x0080U);
809 goto unpin;
810 }
811 vsie_page->itdba_gpa = gpa;
812 scb_s->itdba = hpa;
813 }
814
815 gpa = READ_ONCE(scb_o->gvrd) & ~0x1ffUL;
816 if (gpa && (scb_s->eca & ECA_VX) && !(scb_s->ecd & ECD_HOSTREGMGMT)) {
817 if (gpa < 2 * PAGE_SIZE) {
818 rc = set_validity_icpt(scb_s, 0x1310U);
819 goto unpin;
820 }
821 /*
822 * 512 bytes vector registers cannot cross page boundaries
823 * if this block gets bigger, we have to shadow it.
824 */
825 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
826 if (rc) {
827 rc = set_validity_icpt(scb_s, 0x1310U);
828 goto unpin;
829 }
830 vsie_page->gvrd_gpa = gpa;
831 scb_s->gvrd = hpa;
832 }
833
834 gpa = READ_ONCE(scb_o->riccbd) & ~0x3fUL;
835 if (gpa && (scb_s->ecb3 & ECB3_RI)) {
836 if (gpa < 2 * PAGE_SIZE) {
837 rc = set_validity_icpt(scb_s, 0x0043U);
838 goto unpin;
839 }
840 /* 64 bytes cannot cross page boundaries */
841 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
842 if (rc) {
843 rc = set_validity_icpt(scb_s, 0x0043U);
844 goto unpin;
845 }
846 /* Validity 0x0044 will be checked by SIE */
847 vsie_page->riccbd_gpa = gpa;
848 scb_s->riccbd = hpa;
849 }
850 if (((scb_s->ecb & ECB_GS) && !(scb_s->ecd & ECD_HOSTREGMGMT)) ||
851 (scb_s->ecd & ECD_ETOKENF)) {
852 unsigned long sdnxc;
853
854 gpa = READ_ONCE(scb_o->sdnxo) & ~0xfUL;
855 sdnxc = READ_ONCE(scb_o->sdnxo) & 0xfUL;
856 if (!gpa || gpa < 2 * PAGE_SIZE) {
857 rc = set_validity_icpt(scb_s, 0x10b0U);
858 goto unpin;
859 }
860 if (sdnxc < 6 || sdnxc > 12) {
861 rc = set_validity_icpt(scb_s, 0x10b1U);
862 goto unpin;
863 }
864 if (gpa & ((1 << sdnxc) - 1)) {
865 rc = set_validity_icpt(scb_s, 0x10b2U);
866 goto unpin;
867 }
868 /* Due to alignment rules (checked above) this cannot
869 * cross page boundaries
870 */
871 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
872 if (rc) {
873 rc = set_validity_icpt(scb_s, 0x10b0U);
874 goto unpin;
875 }
876 vsie_page->sdnx_gpa = gpa;
877 scb_s->sdnxo = hpa | sdnxc;
878 }
879 return 0;
880 unpin:
881 unpin_blocks(vcpu, vsie_page);
882 return rc;
883 }
884
885 /* unpin the scb provided by guest 2, marking it as dirty */
unpin_scb(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page,gpa_t gpa)886 static void unpin_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page,
887 gpa_t gpa)
888 {
889 hpa_t hpa = virt_to_phys(vsie_page->scb_o);
890
891 if (hpa)
892 unpin_guest_page(vcpu->kvm, gpa, hpa);
893 vsie_page->scb_o = NULL;
894 }
895
896 /*
897 * Pin the scb at gpa provided by guest 2 at vsie_page->scb_o.
898 *
899 * Returns: - 0 if the scb was pinned.
900 * - > 0 if control has to be given to guest 2
901 */
pin_scb(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page,gpa_t gpa)902 static int pin_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page,
903 gpa_t gpa)
904 {
905 hpa_t hpa;
906 int rc;
907
908 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
909 if (rc) {
910 rc = kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
911 WARN_ON_ONCE(rc);
912 return 1;
913 }
914 vsie_page->scb_o = phys_to_virt(hpa);
915 return 0;
916 }
917
918 /*
919 * Inject a fault into guest 2.
920 *
921 * Returns: - > 0 if control has to be given to guest 2
922 * < 0 if an error occurred during injection.
923 */
inject_fault(struct kvm_vcpu * vcpu,__u16 code,__u64 vaddr,bool write_flag)924 static int inject_fault(struct kvm_vcpu *vcpu, __u16 code, __u64 vaddr,
925 bool write_flag)
926 {
927 struct kvm_s390_pgm_info pgm = {
928 .code = code,
929 .trans_exc_code =
930 /* 0-51: virtual address */
931 (vaddr & 0xfffffffffffff000UL) |
932 /* 52-53: store / fetch */
933 (((unsigned int) !write_flag) + 1) << 10,
934 /* 62-63: asce id (always primary == 0) */
935 .exc_access_id = 0, /* always primary */
936 .op_access_id = 0, /* not MVPG */
937 };
938 int rc;
939
940 if (code == PGM_PROTECTION)
941 pgm.trans_exc_code |= 0x4UL;
942
943 rc = kvm_s390_inject_prog_irq(vcpu, &pgm);
944 return rc ? rc : 1;
945 }
946
947 /*
948 * Handle a fault during vsie execution on a gmap shadow.
949 *
950 * Returns: - 0 if the fault was resolved
951 * - > 0 if control has to be given to guest 2
952 * - < 0 if an error occurred
953 */
handle_fault(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page)954 static int handle_fault(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
955 {
956 int rc;
957
958 if ((current->thread.gmap_int_code & PGM_INT_CODE_MASK) == PGM_PROTECTION)
959 /* we can directly forward all protection exceptions */
960 return inject_fault(vcpu, PGM_PROTECTION,
961 current->thread.gmap_teid.addr * PAGE_SIZE, 1);
962
963 rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap,
964 current->thread.gmap_teid.addr * PAGE_SIZE, NULL);
965 if (rc > 0) {
966 rc = inject_fault(vcpu, rc,
967 current->thread.gmap_teid.addr * PAGE_SIZE,
968 kvm_s390_cur_gmap_fault_is_write());
969 if (rc >= 0)
970 vsie_page->fault_addr = current->thread.gmap_teid.addr * PAGE_SIZE;
971 }
972 return rc;
973 }
974
975 /*
976 * Retry the previous fault that required guest 2 intervention. This avoids
977 * one superfluous SIE re-entry and direct exit.
978 *
979 * Will ignore any errors. The next SIE fault will do proper fault handling.
980 */
handle_last_fault(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page)981 static void handle_last_fault(struct kvm_vcpu *vcpu,
982 struct vsie_page *vsie_page)
983 {
984 if (vsie_page->fault_addr)
985 kvm_s390_shadow_fault(vcpu, vsie_page->gmap,
986 vsie_page->fault_addr, NULL);
987 vsie_page->fault_addr = 0;
988 }
989
clear_vsie_icpt(struct vsie_page * vsie_page)990 static inline void clear_vsie_icpt(struct vsie_page *vsie_page)
991 {
992 vsie_page->scb_s.icptcode = 0;
993 }
994
995 /* rewind the psw and clear the vsie icpt, so we can retry execution */
retry_vsie_icpt(struct vsie_page * vsie_page)996 static void retry_vsie_icpt(struct vsie_page *vsie_page)
997 {
998 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
999 int ilen = insn_length(scb_s->ipa >> 8);
1000
1001 /* take care of EXECUTE instructions */
1002 if (scb_s->icptstatus & 1) {
1003 ilen = (scb_s->icptstatus >> 4) & 0x6;
1004 if (!ilen)
1005 ilen = 4;
1006 }
1007 scb_s->gpsw.addr = __rewind_psw(scb_s->gpsw, ilen);
1008 clear_vsie_icpt(vsie_page);
1009 }
1010
1011 /*
1012 * Try to shadow + enable the guest 2 provided facility list.
1013 * Retry instruction execution if enabled for and provided by guest 2.
1014 *
1015 * Returns: - 0 if handled (retry or guest 2 icpt)
1016 * - > 0 if control has to be given to guest 2
1017 */
handle_stfle(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page)1018 static int handle_stfle(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
1019 {
1020 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
1021 __u32 fac = READ_ONCE(vsie_page->scb_o->fac);
1022
1023 /*
1024 * Alternate-STFLE-Interpretive-Execution facilities are not supported
1025 * -> format-0 flcb
1026 */
1027 if (fac && test_kvm_facility(vcpu->kvm, 7)) {
1028 retry_vsie_icpt(vsie_page);
1029 /*
1030 * The facility list origin (FLO) is in bits 1 - 28 of the FLD
1031 * so we need to mask here before reading.
1032 */
1033 fac = fac & 0x7ffffff8U;
1034 /*
1035 * format-0 -> size of nested guest's facility list == guest's size
1036 * guest's size == host's size, since STFLE is interpretatively executed
1037 * using a format-0 for the guest, too.
1038 */
1039 if (read_guest_real(vcpu, fac, &vsie_page->fac,
1040 stfle_size() * sizeof(u64)))
1041 return set_validity_icpt(scb_s, 0x1090U);
1042 scb_s->fac = (u32)virt_to_phys(&vsie_page->fac);
1043 }
1044 return 0;
1045 }
1046
1047 /*
1048 * Get a register for a nested guest.
1049 * @vcpu the vcpu of the guest
1050 * @vsie_page the vsie_page for the nested guest
1051 * @reg the register number, the upper 4 bits are ignored.
1052 * returns: the value of the register.
1053 */
vsie_get_register(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page,u8 reg)1054 static u64 vsie_get_register(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page, u8 reg)
1055 {
1056 /* no need to validate the parameter and/or perform error handling */
1057 reg &= 0xf;
1058 switch (reg) {
1059 case 15:
1060 return vsie_page->scb_s.gg15;
1061 case 14:
1062 return vsie_page->scb_s.gg14;
1063 default:
1064 return vcpu->run->s.regs.gprs[reg];
1065 }
1066 }
1067
vsie_handle_mvpg(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page)1068 static int vsie_handle_mvpg(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
1069 {
1070 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
1071 unsigned long pei_dest, pei_src, src, dest, mask, prefix;
1072 u64 *pei_block = &vsie_page->scb_o->mcic;
1073 int edat, rc_dest, rc_src;
1074 union ctlreg0 cr0;
1075
1076 cr0.val = vcpu->arch.sie_block->gcr[0];
1077 edat = cr0.edat && test_kvm_facility(vcpu->kvm, 8);
1078 mask = _kvm_s390_logical_to_effective(&scb_s->gpsw, PAGE_MASK);
1079 prefix = scb_s->prefix << GUEST_PREFIX_SHIFT;
1080
1081 dest = vsie_get_register(vcpu, vsie_page, scb_s->ipb >> 20) & mask;
1082 dest = _kvm_s390_real_to_abs(prefix, dest) + scb_s->mso;
1083 src = vsie_get_register(vcpu, vsie_page, scb_s->ipb >> 16) & mask;
1084 src = _kvm_s390_real_to_abs(prefix, src) + scb_s->mso;
1085
1086 rc_dest = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, dest, &pei_dest);
1087 rc_src = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, src, &pei_src);
1088 /*
1089 * Either everything went well, or something non-critical went wrong
1090 * e.g. because of a race. In either case, simply retry.
1091 */
1092 if (rc_dest == -EAGAIN || rc_src == -EAGAIN || (!rc_dest && !rc_src)) {
1093 retry_vsie_icpt(vsie_page);
1094 return -EAGAIN;
1095 }
1096 /* Something more serious went wrong, propagate the error */
1097 if (rc_dest < 0)
1098 return rc_dest;
1099 if (rc_src < 0)
1100 return rc_src;
1101
1102 /* The only possible suppressing exception: just deliver it */
1103 if (rc_dest == PGM_TRANSLATION_SPEC || rc_src == PGM_TRANSLATION_SPEC) {
1104 clear_vsie_icpt(vsie_page);
1105 rc_dest = kvm_s390_inject_program_int(vcpu, PGM_TRANSLATION_SPEC);
1106 WARN_ON_ONCE(rc_dest);
1107 return 1;
1108 }
1109
1110 /*
1111 * Forward the PEI intercept to the guest if it was a page fault, or
1112 * also for segment and region table faults if EDAT applies.
1113 */
1114 if (edat) {
1115 rc_dest = rc_dest == PGM_ASCE_TYPE ? rc_dest : 0;
1116 rc_src = rc_src == PGM_ASCE_TYPE ? rc_src : 0;
1117 } else {
1118 rc_dest = rc_dest != PGM_PAGE_TRANSLATION ? rc_dest : 0;
1119 rc_src = rc_src != PGM_PAGE_TRANSLATION ? rc_src : 0;
1120 }
1121 if (!rc_dest && !rc_src) {
1122 pei_block[0] = pei_dest;
1123 pei_block[1] = pei_src;
1124 return 1;
1125 }
1126
1127 retry_vsie_icpt(vsie_page);
1128
1129 /*
1130 * The host has edat, and the guest does not, or it was an ASCE type
1131 * exception. The host needs to inject the appropriate DAT interrupts
1132 * into the guest.
1133 */
1134 if (rc_dest)
1135 return inject_fault(vcpu, rc_dest, dest, 1);
1136 return inject_fault(vcpu, rc_src, src, 0);
1137 }
1138
1139 /*
1140 * Run the vsie on a shadow scb and a shadow gmap, without any further
1141 * sanity checks, handling SIE faults.
1142 *
1143 * Returns: - 0 everything went fine
1144 * - > 0 if control has to be given to guest 2
1145 * - < 0 if an error occurred
1146 */
do_vsie_run(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page)1147 static int do_vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
1148 __releases(vcpu->kvm->srcu)
1149 __acquires(vcpu->kvm->srcu)
1150 {
1151 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
1152 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
1153 int guest_bp_isolation;
1154 int rc = 0;
1155
1156 handle_last_fault(vcpu, vsie_page);
1157
1158 kvm_vcpu_srcu_read_unlock(vcpu);
1159
1160 /* save current guest state of bp isolation override */
1161 guest_bp_isolation = test_thread_flag(TIF_ISOLATE_BP_GUEST);
1162
1163 /*
1164 * The guest is running with BPBC, so we have to force it on for our
1165 * nested guest. This is done by enabling BPBC globally, so the BPBC
1166 * control in the SCB (which the nested guest can modify) is simply
1167 * ignored.
1168 */
1169 if (test_kvm_facility(vcpu->kvm, 82) &&
1170 vcpu->arch.sie_block->fpf & FPF_BPBC)
1171 set_thread_flag(TIF_ISOLATE_BP_GUEST);
1172
1173 /*
1174 * Simulate a SIE entry of the VCPU (see sie64a), so VCPU blocking
1175 * and VCPU requests also hinder the vSIE from running and lead
1176 * to an immediate exit. kvm_s390_vsie_kick() has to be used to
1177 * also kick the vSIE.
1178 */
1179 vcpu->arch.sie_block->prog0c |= PROG_IN_SIE;
1180 current->thread.gmap_int_code = 0;
1181 barrier();
1182 if (!kvm_s390_vcpu_sie_inhibited(vcpu)) {
1183 local_irq_disable();
1184 guest_timing_enter_irqoff();
1185 rc = kvm_s390_enter_exit_sie(scb_s, vcpu->run->s.regs.gprs, vsie_page->gmap->asce);
1186 guest_timing_exit_irqoff();
1187 local_irq_enable();
1188 }
1189 barrier();
1190 vcpu->arch.sie_block->prog0c &= ~PROG_IN_SIE;
1191
1192 /* restore guest state for bp isolation override */
1193 if (!guest_bp_isolation)
1194 clear_thread_flag(TIF_ISOLATE_BP_GUEST);
1195
1196 kvm_vcpu_srcu_read_lock(vcpu);
1197
1198 if (rc == -EINTR) {
1199 VCPU_EVENT(vcpu, 3, "%s", "machine check");
1200 kvm_s390_reinject_machine_check(vcpu, &vsie_page->mcck_info);
1201 return 0;
1202 }
1203
1204 if (rc > 0)
1205 rc = 0; /* we could still have an icpt */
1206 else if (current->thread.gmap_int_code)
1207 return handle_fault(vcpu, vsie_page);
1208
1209 switch (scb_s->icptcode) {
1210 case ICPT_INST:
1211 if (scb_s->ipa == 0xb2b0)
1212 rc = handle_stfle(vcpu, vsie_page);
1213 break;
1214 case ICPT_STOP:
1215 /* stop not requested by g2 - must have been a kick */
1216 if (!(atomic_read(&scb_o->cpuflags) & CPUSTAT_STOP_INT))
1217 clear_vsie_icpt(vsie_page);
1218 break;
1219 case ICPT_VALIDITY:
1220 if ((scb_s->ipa & 0xf000) != 0xf000)
1221 scb_s->ipa += 0x1000;
1222 break;
1223 case ICPT_PARTEXEC:
1224 if (scb_s->ipa == 0xb254)
1225 rc = vsie_handle_mvpg(vcpu, vsie_page);
1226 break;
1227 }
1228 return rc;
1229 }
1230
release_gmap_shadow(struct vsie_page * vsie_page)1231 static void release_gmap_shadow(struct vsie_page *vsie_page)
1232 {
1233 if (vsie_page->gmap)
1234 gmap_put(vsie_page->gmap);
1235 WRITE_ONCE(vsie_page->gmap, NULL);
1236 prefix_unmapped(vsie_page);
1237 }
1238
acquire_gmap_shadow(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page)1239 static int acquire_gmap_shadow(struct kvm_vcpu *vcpu,
1240 struct vsie_page *vsie_page)
1241 {
1242 unsigned long asce;
1243 union ctlreg0 cr0;
1244 struct gmap *gmap;
1245 int edat;
1246
1247 asce = vcpu->arch.sie_block->gcr[1];
1248 cr0.val = vcpu->arch.sie_block->gcr[0];
1249 edat = cr0.edat && test_kvm_facility(vcpu->kvm, 8);
1250 edat += edat && test_kvm_facility(vcpu->kvm, 78);
1251
1252 /*
1253 * ASCE or EDAT could have changed since last icpt, or the gmap
1254 * we're holding has been unshadowed. If the gmap is still valid,
1255 * we can safely reuse it.
1256 */
1257 if (vsie_page->gmap && gmap_shadow_valid(vsie_page->gmap, asce, edat)) {
1258 vcpu->kvm->stat.gmap_shadow_reuse++;
1259 return 0;
1260 }
1261
1262 /* release the old shadow - if any, and mark the prefix as unmapped */
1263 release_gmap_shadow(vsie_page);
1264 gmap = gmap_shadow(vcpu->arch.gmap, asce, edat);
1265 if (IS_ERR(gmap))
1266 return PTR_ERR(gmap);
1267 vcpu->kvm->stat.gmap_shadow_create++;
1268 WRITE_ONCE(vsie_page->gmap, gmap);
1269 return 0;
1270 }
1271
1272 /*
1273 * Register the shadow scb at the VCPU, e.g. for kicking out of vsie.
1274 */
register_shadow_scb(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page)1275 static void register_shadow_scb(struct kvm_vcpu *vcpu,
1276 struct vsie_page *vsie_page)
1277 {
1278 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
1279
1280 WRITE_ONCE(vcpu->arch.vsie_block, &vsie_page->scb_s);
1281 /*
1282 * External calls have to lead to a kick of the vcpu and
1283 * therefore the vsie -> Simulate Wait state.
1284 */
1285 kvm_s390_set_cpuflags(vcpu, CPUSTAT_WAIT);
1286 /*
1287 * We have to adjust the g3 epoch by the g2 epoch. The epoch will
1288 * automatically be adjusted on tod clock changes via kvm_sync_clock.
1289 */
1290 preempt_disable();
1291 scb_s->epoch += vcpu->kvm->arch.epoch;
1292
1293 if (scb_s->ecd & ECD_MEF) {
1294 scb_s->epdx += vcpu->kvm->arch.epdx;
1295 if (scb_s->epoch < vcpu->kvm->arch.epoch)
1296 scb_s->epdx += 1;
1297 }
1298
1299 preempt_enable();
1300 }
1301
1302 /*
1303 * Unregister a shadow scb from a VCPU.
1304 */
unregister_shadow_scb(struct kvm_vcpu * vcpu)1305 static void unregister_shadow_scb(struct kvm_vcpu *vcpu)
1306 {
1307 kvm_s390_clear_cpuflags(vcpu, CPUSTAT_WAIT);
1308 WRITE_ONCE(vcpu->arch.vsie_block, NULL);
1309 }
1310
1311 /*
1312 * Run the vsie on a shadowed scb, managing the gmap shadow, handling
1313 * prefix pages and faults.
1314 *
1315 * Returns: - 0 if no errors occurred
1316 * - > 0 if control has to be given to guest 2
1317 * - -ENOMEM if out of memory
1318 */
vsie_run(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page)1319 static int vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
1320 {
1321 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
1322 int rc = 0;
1323
1324 while (1) {
1325 rc = acquire_gmap_shadow(vcpu, vsie_page);
1326 if (!rc)
1327 rc = map_prefix(vcpu, vsie_page);
1328 if (!rc) {
1329 update_intervention_requests(vsie_page);
1330 rc = do_vsie_run(vcpu, vsie_page);
1331 }
1332 atomic_andnot(PROG_BLOCK_SIE, &scb_s->prog20);
1333
1334 if (rc == -EAGAIN)
1335 rc = 0;
1336
1337 /*
1338 * Exit the loop if the guest needs to process the intercept
1339 */
1340 if (rc || scb_s->icptcode)
1341 break;
1342
1343 /*
1344 * Exit the loop if the host needs to process an intercept,
1345 * but rewind the PSW to re-enter SIE once that's completed
1346 * instead of passing a "no action" intercept to the guest.
1347 */
1348 if (signal_pending(current) ||
1349 kvm_s390_vcpu_has_irq(vcpu, 0) ||
1350 kvm_s390_vcpu_sie_inhibited(vcpu)) {
1351 kvm_s390_rewind_psw(vcpu, 4);
1352 break;
1353 }
1354 cond_resched();
1355 }
1356
1357 if (rc == -EFAULT) {
1358 /*
1359 * Addressing exceptions are always presentes as intercepts.
1360 * As addressing exceptions are suppressing and our guest 3 PSW
1361 * points at the responsible instruction, we have to
1362 * forward the PSW and set the ilc. If we can't read guest 3
1363 * instruction, we can use an arbitrary ilc. Let's always use
1364 * ilen = 4 for now, so we can avoid reading in guest 3 virtual
1365 * memory. (we could also fake the shadow so the hardware
1366 * handles it).
1367 */
1368 scb_s->icptcode = ICPT_PROGI;
1369 scb_s->iprcc = PGM_ADDRESSING;
1370 scb_s->pgmilc = 4;
1371 scb_s->gpsw.addr = __rewind_psw(scb_s->gpsw, 4);
1372 rc = 1;
1373 }
1374 return rc;
1375 }
1376
1377 /* Try getting a given vsie page, returning "true" on success. */
try_get_vsie_page(struct vsie_page * vsie_page)1378 static inline bool try_get_vsie_page(struct vsie_page *vsie_page)
1379 {
1380 if (test_bit(VSIE_PAGE_IN_USE, &vsie_page->flags))
1381 return false;
1382 return !test_and_set_bit(VSIE_PAGE_IN_USE, &vsie_page->flags);
1383 }
1384
1385 /* Put a vsie page acquired through get_vsie_page / try_get_vsie_page. */
put_vsie_page(struct vsie_page * vsie_page)1386 static void put_vsie_page(struct vsie_page *vsie_page)
1387 {
1388 clear_bit(VSIE_PAGE_IN_USE, &vsie_page->flags);
1389 }
1390
1391 /*
1392 * Get or create a vsie page for a scb address.
1393 *
1394 * Returns: - address of a vsie page (cached or new one)
1395 * - NULL if the same scb address is already used by another VCPU
1396 * - ERR_PTR(-ENOMEM) if out of memory
1397 */
get_vsie_page(struct kvm * kvm,unsigned long addr)1398 static struct vsie_page *get_vsie_page(struct kvm *kvm, unsigned long addr)
1399 {
1400 struct vsie_page *vsie_page;
1401 int nr_vcpus;
1402
1403 rcu_read_lock();
1404 vsie_page = radix_tree_lookup(&kvm->arch.vsie.addr_to_page, addr >> 9);
1405 rcu_read_unlock();
1406 if (vsie_page) {
1407 if (try_get_vsie_page(vsie_page)) {
1408 if (vsie_page->scb_gpa == addr)
1409 return vsie_page;
1410 /*
1411 * We raced with someone reusing + putting this vsie
1412 * page before we grabbed it.
1413 */
1414 put_vsie_page(vsie_page);
1415 }
1416 }
1417
1418 /*
1419 * We want at least #online_vcpus shadows, so every VCPU can execute
1420 * the VSIE in parallel.
1421 */
1422 nr_vcpus = atomic_read(&kvm->online_vcpus);
1423
1424 mutex_lock(&kvm->arch.vsie.mutex);
1425 if (kvm->arch.vsie.page_count < nr_vcpus) {
1426 vsie_page = (void *)__get_free_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO | GFP_DMA);
1427 if (!vsie_page) {
1428 mutex_unlock(&kvm->arch.vsie.mutex);
1429 return ERR_PTR(-ENOMEM);
1430 }
1431 __set_bit(VSIE_PAGE_IN_USE, &vsie_page->flags);
1432 kvm->arch.vsie.pages[kvm->arch.vsie.page_count] = vsie_page;
1433 kvm->arch.vsie.page_count++;
1434 } else {
1435 /* reuse an existing entry that belongs to nobody */
1436 while (true) {
1437 vsie_page = kvm->arch.vsie.pages[kvm->arch.vsie.next];
1438 if (try_get_vsie_page(vsie_page))
1439 break;
1440 kvm->arch.vsie.next++;
1441 kvm->arch.vsie.next %= nr_vcpus;
1442 }
1443 if (vsie_page->scb_gpa != ULONG_MAX)
1444 radix_tree_delete(&kvm->arch.vsie.addr_to_page,
1445 vsie_page->scb_gpa >> 9);
1446 }
1447 /* Mark it as invalid until it resides in the tree. */
1448 vsie_page->scb_gpa = ULONG_MAX;
1449
1450 /* Double use of the same address or allocation failure. */
1451 if (radix_tree_insert(&kvm->arch.vsie.addr_to_page, addr >> 9,
1452 vsie_page)) {
1453 put_vsie_page(vsie_page);
1454 mutex_unlock(&kvm->arch.vsie.mutex);
1455 return NULL;
1456 }
1457 vsie_page->scb_gpa = addr;
1458 mutex_unlock(&kvm->arch.vsie.mutex);
1459
1460 memset(&vsie_page->scb_s, 0, sizeof(struct kvm_s390_sie_block));
1461 release_gmap_shadow(vsie_page);
1462 vsie_page->fault_addr = 0;
1463 vsie_page->scb_s.ihcpu = 0xffffU;
1464 return vsie_page;
1465 }
1466
kvm_s390_handle_vsie(struct kvm_vcpu * vcpu)1467 int kvm_s390_handle_vsie(struct kvm_vcpu *vcpu)
1468 {
1469 struct vsie_page *vsie_page;
1470 unsigned long scb_addr;
1471 int rc;
1472
1473 vcpu->stat.instruction_sie++;
1474 if (!test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_SIEF2))
1475 return -EOPNOTSUPP;
1476 if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
1477 return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
1478
1479 BUILD_BUG_ON(sizeof(struct vsie_page) != PAGE_SIZE);
1480 scb_addr = kvm_s390_get_base_disp_s(vcpu, NULL);
1481
1482 /* 512 byte alignment */
1483 if (unlikely(scb_addr & 0x1ffUL))
1484 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
1485
1486 if (signal_pending(current) || kvm_s390_vcpu_has_irq(vcpu, 0) ||
1487 kvm_s390_vcpu_sie_inhibited(vcpu)) {
1488 kvm_s390_rewind_psw(vcpu, 4);
1489 return 0;
1490 }
1491
1492 vsie_page = get_vsie_page(vcpu->kvm, scb_addr);
1493 if (IS_ERR(vsie_page))
1494 return PTR_ERR(vsie_page);
1495 else if (!vsie_page)
1496 /* double use of sie control block - simply do nothing */
1497 return 0;
1498
1499 rc = pin_scb(vcpu, vsie_page, scb_addr);
1500 if (rc)
1501 goto out_put;
1502 rc = shadow_scb(vcpu, vsie_page);
1503 if (rc)
1504 goto out_unpin_scb;
1505 rc = pin_blocks(vcpu, vsie_page);
1506 if (rc)
1507 goto out_unshadow;
1508 register_shadow_scb(vcpu, vsie_page);
1509 rc = vsie_run(vcpu, vsie_page);
1510 unregister_shadow_scb(vcpu);
1511 unpin_blocks(vcpu, vsie_page);
1512 out_unshadow:
1513 unshadow_scb(vcpu, vsie_page);
1514 out_unpin_scb:
1515 unpin_scb(vcpu, vsie_page, scb_addr);
1516 out_put:
1517 put_vsie_page(vsie_page);
1518
1519 return rc < 0 ? rc : 0;
1520 }
1521
1522 /* Init the vsie data structures. To be called when a vm is initialized. */
kvm_s390_vsie_init(struct kvm * kvm)1523 void kvm_s390_vsie_init(struct kvm *kvm)
1524 {
1525 mutex_init(&kvm->arch.vsie.mutex);
1526 INIT_RADIX_TREE(&kvm->arch.vsie.addr_to_page, GFP_KERNEL_ACCOUNT);
1527 }
1528
1529 /* Destroy the vsie data structures. To be called when a vm is destroyed. */
kvm_s390_vsie_destroy(struct kvm * kvm)1530 void kvm_s390_vsie_destroy(struct kvm *kvm)
1531 {
1532 struct vsie_page *vsie_page;
1533 int i;
1534
1535 mutex_lock(&kvm->arch.vsie.mutex);
1536 for (i = 0; i < kvm->arch.vsie.page_count; i++) {
1537 vsie_page = kvm->arch.vsie.pages[i];
1538 kvm->arch.vsie.pages[i] = NULL;
1539 release_gmap_shadow(vsie_page);
1540 /* free the radix tree entry */
1541 if (vsie_page->scb_gpa != ULONG_MAX)
1542 radix_tree_delete(&kvm->arch.vsie.addr_to_page,
1543 vsie_page->scb_gpa >> 9);
1544 free_page((unsigned long)vsie_page);
1545 }
1546 kvm->arch.vsie.page_count = 0;
1547 mutex_unlock(&kvm->arch.vsie.mutex);
1548 }
1549
kvm_s390_vsie_kick(struct kvm_vcpu * vcpu)1550 void kvm_s390_vsie_kick(struct kvm_vcpu *vcpu)
1551 {
1552 struct kvm_s390_sie_block *scb = READ_ONCE(vcpu->arch.vsie_block);
1553
1554 /*
1555 * Even if the VCPU lets go of the shadow sie block reference, it is
1556 * still valid in the cache. So we can safely kick it.
1557 */
1558 if (scb) {
1559 atomic_or(PROG_BLOCK_SIE, &scb->prog20);
1560 if (scb->prog0c & PROG_IN_SIE)
1561 atomic_or(CPUSTAT_STOP_INT, &scb->cpuflags);
1562 }
1563 }
1564