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