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1/*
2 * kvm nested virtualization support for s390x
3 *
4 * Copyright IBM Corp. 2016
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License (version 2 only)
8 * as published by the Free Software Foundation.
9 *
10 * Author(s): David Hildenbrand <dahi@linux.vnet.ibm.com>
11 */
12#include <linux/vmalloc.h>
13#include <linux/kvm_host.h>
14#include <linux/bug.h>
15#include <linux/list.h>
16#include <linux/bitmap.h>
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 "kvm-s390.h"
23#include "gaccess.h"
24
25struct vsie_page {
26 struct kvm_s390_sie_block scb_s; /* 0x0000 */
27 /* the pinned originial scb */
28 struct kvm_s390_sie_block *scb_o; /* 0x0200 */
29 /* the shadow gmap in use by the vsie_page */
30 struct gmap *gmap; /* 0x0208 */
31 /* address of the last reported fault to guest2 */
32 unsigned long fault_addr; /* 0x0210 */
33 __u8 reserved[0x0700 - 0x0218]; /* 0x0218 */
34 struct kvm_s390_crypto_cb crycb; /* 0x0700 */
35 __u8 fac[S390_ARCH_FAC_LIST_SIZE_BYTE]; /* 0x0800 */
36} __packed;
37
38/* trigger a validity icpt for the given scb */
39static int set_validity_icpt(struct kvm_s390_sie_block *scb,
40 __u16 reason_code)
41{
42 scb->ipa = 0x1000;
43 scb->ipb = ((__u32) reason_code) << 16;
44 scb->icptcode = ICPT_VALIDITY;
45 return 1;
46}
47
48/* mark the prefix as unmapped, this will block the VSIE */
49static void prefix_unmapped(struct vsie_page *vsie_page)
50{
51 atomic_or(PROG_REQUEST, &vsie_page->scb_s.prog20);
52}
53
54/* mark the prefix as unmapped and wait until the VSIE has been left */
55static void prefix_unmapped_sync(struct vsie_page *vsie_page)
56{
57 prefix_unmapped(vsie_page);
58 if (vsie_page->scb_s.prog0c & PROG_IN_SIE)
59 atomic_or(CPUSTAT_STOP_INT, &vsie_page->scb_s.cpuflags);
60 while (vsie_page->scb_s.prog0c & PROG_IN_SIE)
61 cpu_relax();
62}
63
64/* mark the prefix as mapped, this will allow the VSIE to run */
65static void prefix_mapped(struct vsie_page *vsie_page)
66{
67 atomic_andnot(PROG_REQUEST, &vsie_page->scb_s.prog20);
68}
69
70/* test if the prefix is mapped into the gmap shadow */
71static int prefix_is_mapped(struct vsie_page *vsie_page)
72{
73 return !(atomic_read(&vsie_page->scb_s.prog20) & PROG_REQUEST);
74}
75
76/* copy the updated intervention request bits into the shadow scb */
77static void update_intervention_requests(struct vsie_page *vsie_page)
78{
79 const int bits = CPUSTAT_STOP_INT | CPUSTAT_IO_INT | CPUSTAT_EXT_INT;
80 int cpuflags;
81
82 cpuflags = atomic_read(&vsie_page->scb_o->cpuflags);
83 atomic_andnot(bits, &vsie_page->scb_s.cpuflags);
84 atomic_or(cpuflags & bits, &vsie_page->scb_s.cpuflags);
85}
86
87/* shadow (filter and validate) the cpuflags */
88static int prepare_cpuflags(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
89{
90 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
91 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
92 int newflags, cpuflags = atomic_read(&scb_o->cpuflags);
93
94 /* we don't allow ESA/390 guests */
95 if (!(cpuflags & CPUSTAT_ZARCH))
96 return set_validity_icpt(scb_s, 0x0001U);
97
98 if (cpuflags & (CPUSTAT_RRF | CPUSTAT_MCDS))
99 return set_validity_icpt(scb_s, 0x0001U);
100 else if (cpuflags & (CPUSTAT_SLSV | CPUSTAT_SLSR))
101 return set_validity_icpt(scb_s, 0x0007U);
102
103 /* intervention requests will be set later */
104 newflags = CPUSTAT_ZARCH;
105 if (cpuflags & CPUSTAT_GED && test_kvm_facility(vcpu->kvm, 8))
106 newflags |= CPUSTAT_GED;
107 if (cpuflags & CPUSTAT_GED2 && test_kvm_facility(vcpu->kvm, 78)) {
108 if (cpuflags & CPUSTAT_GED)
109 return set_validity_icpt(scb_s, 0x0001U);
110 newflags |= CPUSTAT_GED2;
111 }
112 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_GPERE))
113 newflags |= cpuflags & CPUSTAT_P;
114 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_GSLS))
115 newflags |= cpuflags & CPUSTAT_SM;
116 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_IBS))
117 newflags |= cpuflags & CPUSTAT_IBS;
118
119 atomic_set(&scb_s->cpuflags, newflags);
120 return 0;
121}
122
123/*
124 * Create a shadow copy of the crycb block and setup key wrapping, if
125 * requested for guest 3 and enabled for guest 2.
126 *
127 * We only accept format-1 (no AP in g2), but convert it into format-2
128 * There is nothing to do for format-0.
129 *
130 * Returns: - 0 if shadowed or nothing to do
131 * - > 0 if control has to be given to guest 2
132 */
133static int shadow_crycb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
134{
135 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
136 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
137 u32 crycb_addr = scb_o->crycbd & 0x7ffffff8U;
138 unsigned long *b1, *b2;
139 u8 ecb3_flags;
140
141 scb_s->crycbd = 0;
142 if (!(scb_o->crycbd & vcpu->arch.sie_block->crycbd & CRYCB_FORMAT1))
143 return 0;
144 /* format-1 is supported with message-security-assist extension 3 */
145 if (!test_kvm_facility(vcpu->kvm, 76))
146 return 0;
147 /* we may only allow it if enabled for guest 2 */
148 ecb3_flags = scb_o->ecb3 & vcpu->arch.sie_block->ecb3 &
149 (ECB3_AES | ECB3_DEA);
150 if (!ecb3_flags)
151 return 0;
152
153 if ((crycb_addr & PAGE_MASK) != ((crycb_addr + 128) & PAGE_MASK))
154 return set_validity_icpt(scb_s, 0x003CU);
155 else if (!crycb_addr)
156 return set_validity_icpt(scb_s, 0x0039U);
157
158 /* copy only the wrapping keys */
159 if (read_guest_real(vcpu, crycb_addr + 72, &vsie_page->crycb, 56))
160 return set_validity_icpt(scb_s, 0x0035U);
161
162 scb_s->ecb3 |= ecb3_flags;
163 scb_s->crycbd = ((__u32)(__u64) &vsie_page->crycb) | CRYCB_FORMAT1 |
164 CRYCB_FORMAT2;
165
166 /* xor both blocks in one run */
167 b1 = (unsigned long *) vsie_page->crycb.dea_wrapping_key_mask;
168 b2 = (unsigned long *)
169 vcpu->kvm->arch.crypto.crycb->dea_wrapping_key_mask;
170 /* as 56%8 == 0, bitmap_xor won't overwrite any data */
171 bitmap_xor(b1, b1, b2, BITS_PER_BYTE * 56);
172 return 0;
173}
174
175/* shadow (round up/down) the ibc to avoid validity icpt */
176static void prepare_ibc(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
177{
178 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
179 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
180 __u64 min_ibc = (sclp.ibc >> 16) & 0x0fffU;
181
182 scb_s->ibc = 0;
183 /* ibc installed in g2 and requested for g3 */
184 if (vcpu->kvm->arch.model.ibc && (scb_o->ibc & 0x0fffU)) {
185 scb_s->ibc = scb_o->ibc & 0x0fffU;
186 /* takte care of the minimum ibc level of the machine */
187 if (scb_s->ibc < min_ibc)
188 scb_s->ibc = min_ibc;
189 /* take care of the maximum ibc level set for the guest */
190 if (scb_s->ibc > vcpu->kvm->arch.model.ibc)
191 scb_s->ibc = vcpu->kvm->arch.model.ibc;
192 }
193}
194
195/* unshadow the scb, copying parameters back to the real scb */
196static void unshadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
197{
198 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
199 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
200
201 /* interception */
202 scb_o->icptcode = scb_s->icptcode;
203 scb_o->icptstatus = scb_s->icptstatus;
204 scb_o->ipa = scb_s->ipa;
205 scb_o->ipb = scb_s->ipb;
206 scb_o->gbea = scb_s->gbea;
207
208 /* timer */
209 scb_o->cputm = scb_s->cputm;
210 scb_o->ckc = scb_s->ckc;
211 scb_o->todpr = scb_s->todpr;
212
213 /* guest state */
214 scb_o->gpsw = scb_s->gpsw;
215 scb_o->gg14 = scb_s->gg14;
216 scb_o->gg15 = scb_s->gg15;
217 memcpy(scb_o->gcr, scb_s->gcr, 128);
218 scb_o->pp = scb_s->pp;
219
220 /* interrupt intercept */
221 switch (scb_s->icptcode) {
222 case ICPT_PROGI:
223 case ICPT_INSTPROGI:
224 case ICPT_EXTINT:
225 memcpy((void *)((u64)scb_o + 0xc0),
226 (void *)((u64)scb_s + 0xc0), 0xf0 - 0xc0);
227 break;
228 case ICPT_PARTEXEC:
229 /* MVPG only */
230 memcpy((void *)((u64)scb_o + 0xc0),
231 (void *)((u64)scb_s + 0xc0), 0xd0 - 0xc0);
232 break;
233 }
234
235 if (scb_s->ihcpu != 0xffffU)
236 scb_o->ihcpu = scb_s->ihcpu;
237}
238
239/*
240 * Setup the shadow scb by copying and checking the relevant parts of the g2
241 * provided scb.
242 *
243 * Returns: - 0 if the scb has been shadowed
244 * - > 0 if control has to be given to guest 2
245 */
246static int shadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
247{
248 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
249 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
250 bool had_tx = scb_s->ecb & 0x10U;
251 unsigned long new_mso = 0;
252 int rc;
253
254 /* make sure we don't have any leftovers when reusing the scb */
255 scb_s->icptcode = 0;
256 scb_s->eca = 0;
257 scb_s->ecb = 0;
258 scb_s->ecb2 = 0;
259 scb_s->ecb3 = 0;
260 scb_s->ecd = 0;
261 scb_s->fac = 0;
262
263 rc = prepare_cpuflags(vcpu, vsie_page);
264 if (rc)
265 goto out;
266
267 /* timer */
268 scb_s->cputm = scb_o->cputm;
269 scb_s->ckc = scb_o->ckc;
270 scb_s->todpr = scb_o->todpr;
271 scb_s->epoch = scb_o->epoch;
272
273 /* guest state */
274 scb_s->gpsw = scb_o->gpsw;
275 scb_s->gg14 = scb_o->gg14;
276 scb_s->gg15 = scb_o->gg15;
277 memcpy(scb_s->gcr, scb_o->gcr, 128);
278 scb_s->pp = scb_o->pp;
279
280 /* interception / execution handling */
281 scb_s->gbea = scb_o->gbea;
282 scb_s->lctl = scb_o->lctl;
283 scb_s->svcc = scb_o->svcc;
284 scb_s->ictl = scb_o->ictl;
285 /*
286 * SKEY handling functions can't deal with false setting of PTE invalid
287 * bits. Therefore we cannot provide interpretation and would later
288 * have to provide own emulation handlers.
289 */
290 scb_s->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE;
291 scb_s->icpua = scb_o->icpua;
292
293 if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_SM))
294 new_mso = scb_o->mso & 0xfffffffffff00000UL;
295 /* if the hva of the prefix changes, we have to remap the prefix */
296 if (scb_s->mso != new_mso || scb_s->prefix != scb_o->prefix)
297 prefix_unmapped(vsie_page);
298 /* SIE will do mso/msl validity and exception checks for us */
299 scb_s->msl = scb_o->msl & 0xfffffffffff00000UL;
300 scb_s->mso = new_mso;
301 scb_s->prefix = scb_o->prefix;
302
303 /* We have to definetly flush the tlb if this scb never ran */
304 if (scb_s->ihcpu != 0xffffU)
305 scb_s->ihcpu = scb_o->ihcpu;
306
307 /* MVPG and Protection Exception Interpretation are always available */
308 scb_s->eca |= scb_o->eca & 0x01002000U;
309 /* Host-protection-interruption introduced with ESOP */
310 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_ESOP))
311 scb_s->ecb |= scb_o->ecb & 0x02U;
312 /* transactional execution */
313 if (test_kvm_facility(vcpu->kvm, 73)) {
314 /* remap the prefix is tx is toggled on */
315 if ((scb_o->ecb & 0x10U) && !had_tx)
316 prefix_unmapped(vsie_page);
317 scb_s->ecb |= scb_o->ecb & 0x10U;
318 }
319 /* SIMD */
320 if (test_kvm_facility(vcpu->kvm, 129)) {
321 scb_s->eca |= scb_o->eca & 0x00020000U;
322 scb_s->ecd |= scb_o->ecd & 0x20000000U;
323 }
324 /* Run-time-Instrumentation */
325 if (test_kvm_facility(vcpu->kvm, 64))
326 scb_s->ecb3 |= scb_o->ecb3 & 0x01U;
327 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_SIIF))
328 scb_s->eca |= scb_o->eca & 0x00000001U;
329 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_IB))
330 scb_s->eca |= scb_o->eca & 0x40000000U;
331 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_CEI))
332 scb_s->eca |= scb_o->eca & 0x80000000U;
333
334 prepare_ibc(vcpu, vsie_page);
335 rc = shadow_crycb(vcpu, vsie_page);
336out:
337 if (rc)
338 unshadow_scb(vcpu, vsie_page);
339 return rc;
340}
341
342void kvm_s390_vsie_gmap_notifier(struct gmap *gmap, unsigned long start,
343 unsigned long end)
344{
345 struct kvm *kvm = gmap->private;
346 struct vsie_page *cur;
347 unsigned long prefix;
348 struct page *page;
349 int i;
350
351 if (!gmap_is_shadow(gmap))
352 return;
353 if (start >= 1UL << 31)
354 /* We are only interested in prefix pages */
355 return;
356
357 /*
358 * Only new shadow blocks are added to the list during runtime,
359 * therefore we can safely reference them all the time.
360 */
361 for (i = 0; i < kvm->arch.vsie.page_count; i++) {
362 page = READ_ONCE(kvm->arch.vsie.pages[i]);
363 if (!page)
364 continue;
365 cur = page_to_virt(page);
366 if (READ_ONCE(cur->gmap) != gmap)
367 continue;
368 prefix = cur->scb_s.prefix << GUEST_PREFIX_SHIFT;
369 /* with mso/msl, the prefix lies at an offset */
370 prefix += cur->scb_s.mso;
371 if (prefix <= end && start <= prefix + 2 * PAGE_SIZE - 1)
372 prefix_unmapped_sync(cur);
373 }
374}
375
376/*
377 * Map the first prefix page and if tx is enabled also the second prefix page.
378 *
379 * The prefix will be protected, a gmap notifier will inform about unmaps.
380 * The shadow scb must not be executed until the prefix is remapped, this is
381 * guaranteed by properly handling PROG_REQUEST.
382 *
383 * Returns: - 0 on if successfully mapped or already mapped
384 * - > 0 if control has to be given to guest 2
385 * - -EAGAIN if the caller can retry immediately
386 * - -ENOMEM if out of memory
387 */
388static int map_prefix(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
389{
390 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
391 u64 prefix = scb_s->prefix << GUEST_PREFIX_SHIFT;
392 int rc;
393
394 if (prefix_is_mapped(vsie_page))
395 return 0;
396
397 /* mark it as mapped so we can catch any concurrent unmappers */
398 prefix_mapped(vsie_page);
399
400 /* with mso/msl, the prefix lies at offset *mso* */
401 prefix += scb_s->mso;
402
403 rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, prefix);
404 if (!rc && (scb_s->ecb & 0x10U))
405 rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap,
406 prefix + PAGE_SIZE);
407 /*
408 * We don't have to mprotect, we will be called for all unshadows.
409 * SIE will detect if protection applies and trigger a validity.
410 */
411 if (rc)
412 prefix_unmapped(vsie_page);
413 if (rc > 0 || rc == -EFAULT)
414 rc = set_validity_icpt(scb_s, 0x0037U);
415 return rc;
416}
417
418/*
419 * Pin the guest page given by gpa and set hpa to the pinned host address.
420 * Will always be pinned writable.
421 *
422 * Returns: - 0 on success
423 * - -EINVAL if the gpa is not valid guest storage
424 * - -ENOMEM if out of memory
425 */
426static int pin_guest_page(struct kvm *kvm, gpa_t gpa, hpa_t *hpa)
427{
428 struct page *page;
429 hva_t hva;
430 int rc;
431
432 hva = gfn_to_hva(kvm, gpa_to_gfn(gpa));
433 if (kvm_is_error_hva(hva))
434 return -EINVAL;
435 rc = get_user_pages_fast(hva, 1, 1, &page);
436 if (rc < 0)
437 return rc;
438 else if (rc != 1)
439 return -ENOMEM;
440 *hpa = (hpa_t) page_to_virt(page) + (gpa & ~PAGE_MASK);
441 return 0;
442}
443
444/* Unpins a page previously pinned via pin_guest_page, marking it as dirty. */
445static void unpin_guest_page(struct kvm *kvm, gpa_t gpa, hpa_t hpa)
446{
447 struct page *page;
448
449 page = virt_to_page(hpa);
450 set_page_dirty_lock(page);
451 put_page(page);
452 /* mark the page always as dirty for migration */
453 mark_page_dirty(kvm, gpa_to_gfn(gpa));
454}
455
456/* unpin all blocks previously pinned by pin_blocks(), marking them dirty */
457static void unpin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
458{
459 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
460 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
461 hpa_t hpa;
462 gpa_t gpa;
463
464 hpa = (u64) scb_s->scaoh << 32 | scb_s->scaol;
465 if (hpa) {
466 gpa = scb_o->scaol & ~0xfUL;
467 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_64BSCAO))
468 gpa |= (u64) scb_o->scaoh << 32;
469 unpin_guest_page(vcpu->kvm, gpa, hpa);
470 scb_s->scaol = 0;
471 scb_s->scaoh = 0;
472 }
473
474 hpa = scb_s->itdba;
475 if (hpa) {
476 gpa = scb_o->itdba & ~0xffUL;
477 unpin_guest_page(vcpu->kvm, gpa, hpa);
478 scb_s->itdba = 0;
479 }
480
481 hpa = scb_s->gvrd;
482 if (hpa) {
483 gpa = scb_o->gvrd & ~0x1ffUL;
484 unpin_guest_page(vcpu->kvm, gpa, hpa);
485 scb_s->gvrd = 0;
486 }
487
488 hpa = scb_s->riccbd;
489 if (hpa) {
490 gpa = scb_o->riccbd & ~0x3fUL;
491 unpin_guest_page(vcpu->kvm, gpa, hpa);
492 scb_s->riccbd = 0;
493 }
494}
495
496/*
497 * Instead of shadowing some blocks, we can simply forward them because the
498 * addresses in the scb are 64 bit long.
499 *
500 * This works as long as the data lies in one page. If blocks ever exceed one
501 * page, we have to fall back to shadowing.
502 *
503 * As we reuse the sca, the vcpu pointers contained in it are invalid. We must
504 * therefore not enable any facilities that access these pointers (e.g. SIGPIF).
505 *
506 * Returns: - 0 if all blocks were pinned.
507 * - > 0 if control has to be given to guest 2
508 * - -ENOMEM if out of memory
509 */
510static int pin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
511{
512 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
513 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
514 hpa_t hpa;
515 gpa_t gpa;
516 int rc = 0;
517
518 gpa = scb_o->scaol & ~0xfUL;
519 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_64BSCAO))
520 gpa |= (u64) scb_o->scaoh << 32;
521 if (gpa) {
522 if (!(gpa & ~0x1fffUL))
523 rc = set_validity_icpt(scb_s, 0x0038U);
524 else if ((gpa & ~0x1fffUL) == kvm_s390_get_prefix(vcpu))
525 rc = set_validity_icpt(scb_s, 0x0011U);
526 else if ((gpa & PAGE_MASK) !=
527 ((gpa + sizeof(struct bsca_block) - 1) & PAGE_MASK))
528 rc = set_validity_icpt(scb_s, 0x003bU);
529 if (!rc) {
530 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
531 if (rc == -EINVAL)
532 rc = set_validity_icpt(scb_s, 0x0034U);
533 }
534 if (rc)
535 goto unpin;
536 scb_s->scaoh = (u32)((u64)hpa >> 32);
537 scb_s->scaol = (u32)(u64)hpa;
538 }
539
540 gpa = scb_o->itdba & ~0xffUL;
541 if (gpa && (scb_s->ecb & 0x10U)) {
542 if (!(gpa & ~0x1fffU)) {
543 rc = set_validity_icpt(scb_s, 0x0080U);
544 goto unpin;
545 }
546 /* 256 bytes cannot cross page boundaries */
547 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
548 if (rc == -EINVAL)
549 rc = set_validity_icpt(scb_s, 0x0080U);
550 if (rc)
551 goto unpin;
552 scb_s->itdba = hpa;
553 }
554
555 gpa = scb_o->gvrd & ~0x1ffUL;
556 if (gpa && (scb_s->eca & 0x00020000U) &&
557 !(scb_s->ecd & 0x20000000U)) {
558 if (!(gpa & ~0x1fffUL)) {
559 rc = set_validity_icpt(scb_s, 0x1310U);
560 goto unpin;
561 }
562 /*
563 * 512 bytes vector registers cannot cross page boundaries
564 * if this block gets bigger, we have to shadow it.
565 */
566 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
567 if (rc == -EINVAL)
568 rc = set_validity_icpt(scb_s, 0x1310U);
569 if (rc)
570 goto unpin;
571 scb_s->gvrd = hpa;
572 }
573
574 gpa = scb_o->riccbd & ~0x3fUL;
575 if (gpa && (scb_s->ecb3 & 0x01U)) {
576 if (!(gpa & ~0x1fffUL)) {
577 rc = set_validity_icpt(scb_s, 0x0043U);
578 goto unpin;
579 }
580 /* 64 bytes cannot cross page boundaries */
581 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
582 if (rc == -EINVAL)
583 rc = set_validity_icpt(scb_s, 0x0043U);
584 /* Validity 0x0044 will be checked by SIE */
585 if (rc)
586 goto unpin;
587 scb_s->riccbd = hpa;
588 }
589 return 0;
590unpin:
591 unpin_blocks(vcpu, vsie_page);
592 return rc;
593}
594
595/* unpin the scb provided by guest 2, marking it as dirty */
596static void unpin_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page,
597 gpa_t gpa)
598{
599 hpa_t hpa = (hpa_t) vsie_page->scb_o;
600
601 if (hpa)
602 unpin_guest_page(vcpu->kvm, gpa, hpa);
603 vsie_page->scb_o = NULL;
604}
605
606/*
607 * Pin the scb at gpa provided by guest 2 at vsie_page->scb_o.
608 *
609 * Returns: - 0 if the scb was pinned.
610 * - > 0 if control has to be given to guest 2
611 * - -ENOMEM if out of memory
612 */
613static int pin_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page,
614 gpa_t gpa)
615{
616 hpa_t hpa;
617 int rc;
618
619 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
620 if (rc == -EINVAL) {
621 rc = kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
622 if (!rc)
623 rc = 1;
624 }
625 if (!rc)
626 vsie_page->scb_o = (struct kvm_s390_sie_block *) hpa;
627 return rc;
628}
629
630/*
631 * Inject a fault into guest 2.
632 *
633 * Returns: - > 0 if control has to be given to guest 2
634 * < 0 if an error occurred during injection.
635 */
636static int inject_fault(struct kvm_vcpu *vcpu, __u16 code, __u64 vaddr,
637 bool write_flag)
638{
639 struct kvm_s390_pgm_info pgm = {
640 .code = code,
641 .trans_exc_code =
642 /* 0-51: virtual address */
643 (vaddr & 0xfffffffffffff000UL) |
644 /* 52-53: store / fetch */
645 (((unsigned int) !write_flag) + 1) << 10,
646 /* 62-63: asce id (alway primary == 0) */
647 .exc_access_id = 0, /* always primary */
648 .op_access_id = 0, /* not MVPG */
649 };
650 int rc;
651
652 if (code == PGM_PROTECTION)
653 pgm.trans_exc_code |= 0x4UL;
654
655 rc = kvm_s390_inject_prog_irq(vcpu, &pgm);
656 return rc ? rc : 1;
657}
658
659/*
660 * Handle a fault during vsie execution on a gmap shadow.
661 *
662 * Returns: - 0 if the fault was resolved
663 * - > 0 if control has to be given to guest 2
664 * - < 0 if an error occurred
665 */
666static int handle_fault(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
667{
668 int rc;
669
670 if (current->thread.gmap_int_code == PGM_PROTECTION)
671 /* we can directly forward all protection exceptions */
672 return inject_fault(vcpu, PGM_PROTECTION,
673 current->thread.gmap_addr, 1);
674
675 rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap,
676 current->thread.gmap_addr);
677 if (rc > 0) {
678 rc = inject_fault(vcpu, rc,
679 current->thread.gmap_addr,
680 current->thread.gmap_write_flag);
681 if (rc >= 0)
682 vsie_page->fault_addr = current->thread.gmap_addr;
683 }
684 return rc;
685}
686
687/*
688 * Retry the previous fault that required guest 2 intervention. This avoids
689 * one superfluous SIE re-entry and direct exit.
690 *
691 * Will ignore any errors. The next SIE fault will do proper fault handling.
692 */
693static void handle_last_fault(struct kvm_vcpu *vcpu,
694 struct vsie_page *vsie_page)
695{
696 if (vsie_page->fault_addr)
697 kvm_s390_shadow_fault(vcpu, vsie_page->gmap,
698 vsie_page->fault_addr);
699 vsie_page->fault_addr = 0;
700}
701
702static inline void clear_vsie_icpt(struct vsie_page *vsie_page)
703{
704 vsie_page->scb_s.icptcode = 0;
705}
706
707/* rewind the psw and clear the vsie icpt, so we can retry execution */
708static void retry_vsie_icpt(struct vsie_page *vsie_page)
709{
710 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
711 int ilen = insn_length(scb_s->ipa >> 8);
712
713 /* take care of EXECUTE instructions */
714 if (scb_s->icptstatus & 1) {
715 ilen = (scb_s->icptstatus >> 4) & 0x6;
716 if (!ilen)
717 ilen = 4;
718 }
719 scb_s->gpsw.addr = __rewind_psw(scb_s->gpsw, ilen);
720 clear_vsie_icpt(vsie_page);
721}
722
723/*
724 * Try to shadow + enable the guest 2 provided facility list.
725 * Retry instruction execution if enabled for and provided by guest 2.
726 *
727 * Returns: - 0 if handled (retry or guest 2 icpt)
728 * - > 0 if control has to be given to guest 2
729 */
730static int handle_stfle(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
731{
732 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
733 __u32 fac = vsie_page->scb_o->fac & 0x7ffffff8U;
734
735 if (fac && test_kvm_facility(vcpu->kvm, 7)) {
736 retry_vsie_icpt(vsie_page);
737 if (read_guest_real(vcpu, fac, &vsie_page->fac,
738 sizeof(vsie_page->fac)))
739 return set_validity_icpt(scb_s, 0x1090U);
740 scb_s->fac = (__u32)(__u64) &vsie_page->fac;
741 }
742 return 0;
743}
744
745/*
746 * Run the vsie on a shadow scb and a shadow gmap, without any further
747 * sanity checks, handling SIE faults.
748 *
749 * Returns: - 0 everything went fine
750 * - > 0 if control has to be given to guest 2
751 * - < 0 if an error occurred
752 */
753static int do_vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
754{
755 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
756 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
757 int rc;
758
759 handle_last_fault(vcpu, vsie_page);
760
761 if (need_resched())
762 schedule();
763 if (test_cpu_flag(CIF_MCCK_PENDING))
764 s390_handle_mcck();
765
766 srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
767 local_irq_disable();
768 guest_enter_irqoff();
769 local_irq_enable();
770
771 rc = sie64a(scb_s, vcpu->run->s.regs.gprs);
772
773 local_irq_disable();
774 guest_exit_irqoff();
775 local_irq_enable();
776 vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
777
778 if (rc > 0)
779 rc = 0; /* we could still have an icpt */
780 else if (rc == -EFAULT)
781 return handle_fault(vcpu, vsie_page);
782
783 switch (scb_s->icptcode) {
784 case ICPT_INST:
785 if (scb_s->ipa == 0xb2b0)
786 rc = handle_stfle(vcpu, vsie_page);
787 break;
788 case ICPT_STOP:
789 /* stop not requested by g2 - must have been a kick */
790 if (!(atomic_read(&scb_o->cpuflags) & CPUSTAT_STOP_INT))
791 clear_vsie_icpt(vsie_page);
792 break;
793 case ICPT_VALIDITY:
794 if ((scb_s->ipa & 0xf000) != 0xf000)
795 scb_s->ipa += 0x1000;
796 break;
797 }
798 return rc;
799}
800
801static void release_gmap_shadow(struct vsie_page *vsie_page)
802{
803 if (vsie_page->gmap)
804 gmap_put(vsie_page->gmap);
805 WRITE_ONCE(vsie_page->gmap, NULL);
806 prefix_unmapped(vsie_page);
807}
808
809static int acquire_gmap_shadow(struct kvm_vcpu *vcpu,
810 struct vsie_page *vsie_page)
811{
812 unsigned long asce;
813 union ctlreg0 cr0;
814 struct gmap *gmap;
815 int edat;
816
817 asce = vcpu->arch.sie_block->gcr[1];
818 cr0.val = vcpu->arch.sie_block->gcr[0];
819 edat = cr0.edat && test_kvm_facility(vcpu->kvm, 8);
820 edat += edat && test_kvm_facility(vcpu->kvm, 78);
821
822 /*
823 * ASCE or EDAT could have changed since last icpt, or the gmap
824 * we're holding has been unshadowed. If the gmap is still valid,
825 * we can safely reuse it.
826 */
827 if (vsie_page->gmap && gmap_shadow_valid(vsie_page->gmap, asce, edat))
828 return 0;
829
830 /* release the old shadow - if any, and mark the prefix as unmapped */
831 release_gmap_shadow(vsie_page);
832 gmap = gmap_shadow(vcpu->arch.gmap, asce, edat);
833 if (IS_ERR(gmap))
834 return PTR_ERR(gmap);
835 gmap->private = vcpu->kvm;
836 WRITE_ONCE(vsie_page->gmap, gmap);
837 return 0;
838}
839
840/*
841 * Register the shadow scb at the VCPU, e.g. for kicking out of vsie.
842 */
843static void register_shadow_scb(struct kvm_vcpu *vcpu,
844 struct vsie_page *vsie_page)
845{
846 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
847
848 WRITE_ONCE(vcpu->arch.vsie_block, &vsie_page->scb_s);
849 /*
850 * External calls have to lead to a kick of the vcpu and
851 * therefore the vsie -> Simulate Wait state.
852 */
853 atomic_or(CPUSTAT_WAIT, &vcpu->arch.sie_block->cpuflags);
854 /*
855 * We have to adjust the g3 epoch by the g2 epoch. The epoch will
856 * automatically be adjusted on tod clock changes via kvm_sync_clock.
857 */
858 preempt_disable();
859 scb_s->epoch += vcpu->kvm->arch.epoch;
860 preempt_enable();
861}
862
863/*
864 * Unregister a shadow scb from a VCPU.
865 */
866static void unregister_shadow_scb(struct kvm_vcpu *vcpu)
867{
868 atomic_andnot(CPUSTAT_WAIT, &vcpu->arch.sie_block->cpuflags);
869 WRITE_ONCE(vcpu->arch.vsie_block, NULL);
870}
871
872/*
873 * Run the vsie on a shadowed scb, managing the gmap shadow, handling
874 * prefix pages and faults.
875 *
876 * Returns: - 0 if no errors occurred
877 * - > 0 if control has to be given to guest 2
878 * - -ENOMEM if out of memory
879 */
880static int vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
881{
882 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
883 int rc = 0;
884
885 while (1) {
886 rc = acquire_gmap_shadow(vcpu, vsie_page);
887 if (!rc)
888 rc = map_prefix(vcpu, vsie_page);
889 if (!rc) {
890 gmap_enable(vsie_page->gmap);
891 update_intervention_requests(vsie_page);
892 rc = do_vsie_run(vcpu, vsie_page);
893 gmap_enable(vcpu->arch.gmap);
894 }
895 atomic_andnot(PROG_BLOCK_SIE, &scb_s->prog20);
896
897 if (rc == -EAGAIN)
898 rc = 0;
899 if (rc || scb_s->icptcode || signal_pending(current) ||
900 kvm_s390_vcpu_has_irq(vcpu, 0))
901 break;
902 };
903
904 if (rc == -EFAULT) {
905 /*
906 * Addressing exceptions are always presentes as intercepts.
907 * As addressing exceptions are suppressing and our guest 3 PSW
908 * points at the responsible instruction, we have to
909 * forward the PSW and set the ilc. If we can't read guest 3
910 * instruction, we can use an arbitrary ilc. Let's always use
911 * ilen = 4 for now, so we can avoid reading in guest 3 virtual
912 * memory. (we could also fake the shadow so the hardware
913 * handles it).
914 */
915 scb_s->icptcode = ICPT_PROGI;
916 scb_s->iprcc = PGM_ADDRESSING;
917 scb_s->pgmilc = 4;
918 scb_s->gpsw.addr = __rewind_psw(scb_s->gpsw, 4);
919 }
920 return rc;
921}
922
923/*
924 * Get or create a vsie page for a scb address.
925 *
926 * Returns: - address of a vsie page (cached or new one)
927 * - NULL if the same scb address is already used by another VCPU
928 * - ERR_PTR(-ENOMEM) if out of memory
929 */
930static struct vsie_page *get_vsie_page(struct kvm *kvm, unsigned long addr)
931{
932 struct vsie_page *vsie_page;
933 struct page *page;
934 int nr_vcpus;
935
936 rcu_read_lock();
937 page = radix_tree_lookup(&kvm->arch.vsie.addr_to_page, addr >> 9);
938 rcu_read_unlock();
939 if (page) {
940 if (page_ref_inc_return(page) == 2)
941 return page_to_virt(page);
942 page_ref_dec(page);
943 }
944
945 /*
946 * We want at least #online_vcpus shadows, so every VCPU can execute
947 * the VSIE in parallel.
948 */
949 nr_vcpus = atomic_read(&kvm->online_vcpus);
950
951 mutex_lock(&kvm->arch.vsie.mutex);
952 if (kvm->arch.vsie.page_count < nr_vcpus) {
953 page = alloc_page(GFP_KERNEL | __GFP_ZERO | GFP_DMA);
954 if (!page) {
955 mutex_unlock(&kvm->arch.vsie.mutex);
956 return ERR_PTR(-ENOMEM);
957 }
958 page_ref_inc(page);
959 kvm->arch.vsie.pages[kvm->arch.vsie.page_count] = page;
960 kvm->arch.vsie.page_count++;
961 } else {
962 /* reuse an existing entry that belongs to nobody */
963 while (true) {
964 page = kvm->arch.vsie.pages[kvm->arch.vsie.next];
965 if (page_ref_inc_return(page) == 2)
966 break;
967 page_ref_dec(page);
968 kvm->arch.vsie.next++;
969 kvm->arch.vsie.next %= nr_vcpus;
970 }
971 radix_tree_delete(&kvm->arch.vsie.addr_to_page, page->index >> 9);
972 }
973 page->index = addr;
974 /* double use of the same address */
975 if (radix_tree_insert(&kvm->arch.vsie.addr_to_page, addr >> 9, page)) {
976 page_ref_dec(page);
977 mutex_unlock(&kvm->arch.vsie.mutex);
978 return NULL;
979 }
980 mutex_unlock(&kvm->arch.vsie.mutex);
981
982 vsie_page = page_to_virt(page);
983 memset(&vsie_page->scb_s, 0, sizeof(struct kvm_s390_sie_block));
984 release_gmap_shadow(vsie_page);
985 vsie_page->fault_addr = 0;
986 vsie_page->scb_s.ihcpu = 0xffffU;
987 return vsie_page;
988}
989
990/* put a vsie page acquired via get_vsie_page */
991static void put_vsie_page(struct kvm *kvm, struct vsie_page *vsie_page)
992{
993 struct page *page = pfn_to_page(__pa(vsie_page) >> PAGE_SHIFT);
994
995 page_ref_dec(page);
996}
997
998int kvm_s390_handle_vsie(struct kvm_vcpu *vcpu)
999{
1000 struct vsie_page *vsie_page;
1001 unsigned long scb_addr;
1002 int rc;
1003
1004 vcpu->stat.instruction_sie++;
1005 if (!test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_SIEF2))
1006 return -EOPNOTSUPP;
1007 if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
1008 return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
1009
1010 BUILD_BUG_ON(sizeof(struct vsie_page) != 4096);
1011 scb_addr = kvm_s390_get_base_disp_s(vcpu, NULL);
1012
1013 /* 512 byte alignment */
1014 if (unlikely(scb_addr & 0x1ffUL))
1015 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
1016
1017 if (signal_pending(current) || kvm_s390_vcpu_has_irq(vcpu, 0))
1018 return 0;
1019
1020 vsie_page = get_vsie_page(vcpu->kvm, scb_addr);
1021 if (IS_ERR(vsie_page))
1022 return PTR_ERR(vsie_page);
1023 else if (!vsie_page)
1024 /* double use of sie control block - simply do nothing */
1025 return 0;
1026
1027 rc = pin_scb(vcpu, vsie_page, scb_addr);
1028 if (rc)
1029 goto out_put;
1030 rc = shadow_scb(vcpu, vsie_page);
1031 if (rc)
1032 goto out_unpin_scb;
1033 rc = pin_blocks(vcpu, vsie_page);
1034 if (rc)
1035 goto out_unshadow;
1036 register_shadow_scb(vcpu, vsie_page);
1037 rc = vsie_run(vcpu, vsie_page);
1038 unregister_shadow_scb(vcpu);
1039 unpin_blocks(vcpu, vsie_page);
1040out_unshadow:
1041 unshadow_scb(vcpu, vsie_page);
1042out_unpin_scb:
1043 unpin_scb(vcpu, vsie_page, scb_addr);
1044out_put:
1045 put_vsie_page(vcpu->kvm, vsie_page);
1046
1047 return rc < 0 ? rc : 0;
1048}
1049
1050/* Init the vsie data structures. To be called when a vm is initialized. */
1051void kvm_s390_vsie_init(struct kvm *kvm)
1052{
1053 mutex_init(&kvm->arch.vsie.mutex);
1054 INIT_RADIX_TREE(&kvm->arch.vsie.addr_to_page, GFP_KERNEL);
1055}
1056
1057/* Destroy the vsie data structures. To be called when a vm is destroyed. */
1058void kvm_s390_vsie_destroy(struct kvm *kvm)
1059{
1060 struct vsie_page *vsie_page;
1061 struct page *page;
1062 int i;
1063
1064 mutex_lock(&kvm->arch.vsie.mutex);
1065 for (i = 0; i < kvm->arch.vsie.page_count; i++) {
1066 page = kvm->arch.vsie.pages[i];
1067 kvm->arch.vsie.pages[i] = NULL;
1068 vsie_page = page_to_virt(page);
1069 release_gmap_shadow(vsie_page);
1070 /* free the radix tree entry */
1071 radix_tree_delete(&kvm->arch.vsie.addr_to_page, page->index >> 9);
1072 __free_page(page);
1073 }
1074 kvm->arch.vsie.page_count = 0;
1075 mutex_unlock(&kvm->arch.vsie.mutex);
1076}
1077
1078void kvm_s390_vsie_kick(struct kvm_vcpu *vcpu)
1079{
1080 struct kvm_s390_sie_block *scb = READ_ONCE(vcpu->arch.vsie_block);
1081
1082 /*
1083 * Even if the VCPU lets go of the shadow sie block reference, it is
1084 * still valid in the cache. So we can safely kick it.
1085 */
1086 if (scb) {
1087 atomic_or(PROG_BLOCK_SIE, &scb->prog20);
1088 if (scb->prog0c & PROG_IN_SIE)
1089 atomic_or(CPUSTAT_STOP_INT, &scb->cpuflags);
1090 }
1091}
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
16#include <asm/gmap.h>
17#include <asm/mmu_context.h>
18#include <asm/sclp.h>
19#include <asm/nmi.h>
20#include <asm/dis.h>
21#include "kvm-s390.h"
22#include "gaccess.h"
23
24struct vsie_page {
25 struct kvm_s390_sie_block scb_s; /* 0x0000 */
26 /*
27 * the backup info for machine check. ensure it's at
28 * the same offset as that in struct sie_page!
29 */
30 struct mcck_volatile_info mcck_info; /* 0x0200 */
31 /*
32 * The pinned original scb. Be aware that other VCPUs can modify
33 * it while we read from it. Values that are used for conditions or
34 * are reused conditionally, should be accessed via READ_ONCE.
35 */
36 struct kvm_s390_sie_block *scb_o; /* 0x0218 */
37 /* the shadow gmap in use by the vsie_page */
38 struct gmap *gmap; /* 0x0220 */
39 /* address of the last reported fault to guest2 */
40 unsigned long fault_addr; /* 0x0228 */
41 /* calculated guest addresses of satellite control blocks */
42 gpa_t sca_gpa; /* 0x0230 */
43 gpa_t itdba_gpa; /* 0x0238 */
44 gpa_t gvrd_gpa; /* 0x0240 */
45 gpa_t riccbd_gpa; /* 0x0248 */
46 gpa_t sdnx_gpa; /* 0x0250 */
47 __u8 reserved[0x0700 - 0x0258]; /* 0x0258 */
48 struct kvm_s390_crypto_cb crycb; /* 0x0700 */
49 __u8 fac[S390_ARCH_FAC_LIST_SIZE_BYTE]; /* 0x0800 */
50};
51
52/* trigger a validity icpt for the given scb */
53static int set_validity_icpt(struct kvm_s390_sie_block *scb,
54 __u16 reason_code)
55{
56 scb->ipa = 0x1000;
57 scb->ipb = ((__u32) reason_code) << 16;
58 scb->icptcode = ICPT_VALIDITY;
59 return 1;
60}
61
62/* mark the prefix as unmapped, this will block the VSIE */
63static void prefix_unmapped(struct vsie_page *vsie_page)
64{
65 atomic_or(PROG_REQUEST, &vsie_page->scb_s.prog20);
66}
67
68/* mark the prefix as unmapped and wait until the VSIE has been left */
69static void prefix_unmapped_sync(struct vsie_page *vsie_page)
70{
71 prefix_unmapped(vsie_page);
72 if (vsie_page->scb_s.prog0c & PROG_IN_SIE)
73 atomic_or(CPUSTAT_STOP_INT, &vsie_page->scb_s.cpuflags);
74 while (vsie_page->scb_s.prog0c & PROG_IN_SIE)
75 cpu_relax();
76}
77
78/* mark the prefix as mapped, this will allow the VSIE to run */
79static void prefix_mapped(struct vsie_page *vsie_page)
80{
81 atomic_andnot(PROG_REQUEST, &vsie_page->scb_s.prog20);
82}
83
84/* test if the prefix is mapped into the gmap shadow */
85static int prefix_is_mapped(struct vsie_page *vsie_page)
86{
87 return !(atomic_read(&vsie_page->scb_s.prog20) & PROG_REQUEST);
88}
89
90/* copy the updated intervention request bits into the shadow scb */
91static void update_intervention_requests(struct vsie_page *vsie_page)
92{
93 const int bits = CPUSTAT_STOP_INT | CPUSTAT_IO_INT | CPUSTAT_EXT_INT;
94 int cpuflags;
95
96 cpuflags = atomic_read(&vsie_page->scb_o->cpuflags);
97 atomic_andnot(bits, &vsie_page->scb_s.cpuflags);
98 atomic_or(cpuflags & bits, &vsie_page->scb_s.cpuflags);
99}
100
101/* shadow (filter and validate) the cpuflags */
102static int prepare_cpuflags(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
103{
104 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
105 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
106 int newflags, cpuflags = atomic_read(&scb_o->cpuflags);
107
108 /* we don't allow ESA/390 guests */
109 if (!(cpuflags & CPUSTAT_ZARCH))
110 return set_validity_icpt(scb_s, 0x0001U);
111
112 if (cpuflags & (CPUSTAT_RRF | CPUSTAT_MCDS))
113 return set_validity_icpt(scb_s, 0x0001U);
114 else if (cpuflags & (CPUSTAT_SLSV | CPUSTAT_SLSR))
115 return set_validity_icpt(scb_s, 0x0007U);
116
117 /* intervention requests will be set later */
118 newflags = CPUSTAT_ZARCH;
119 if (cpuflags & CPUSTAT_GED && test_kvm_facility(vcpu->kvm, 8))
120 newflags |= CPUSTAT_GED;
121 if (cpuflags & CPUSTAT_GED2 && test_kvm_facility(vcpu->kvm, 78)) {
122 if (cpuflags & CPUSTAT_GED)
123 return set_validity_icpt(scb_s, 0x0001U);
124 newflags |= CPUSTAT_GED2;
125 }
126 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_GPERE))
127 newflags |= cpuflags & CPUSTAT_P;
128 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_GSLS))
129 newflags |= cpuflags & CPUSTAT_SM;
130 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_IBS))
131 newflags |= cpuflags & CPUSTAT_IBS;
132 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_KSS))
133 newflags |= cpuflags & CPUSTAT_KSS;
134
135 atomic_set(&scb_s->cpuflags, newflags);
136 return 0;
137}
138/* Copy to APCB FORMAT1 from APCB FORMAT0 */
139static int setup_apcb10(struct kvm_vcpu *vcpu, struct kvm_s390_apcb1 *apcb_s,
140 unsigned long apcb_o, struct kvm_s390_apcb1 *apcb_h)
141{
142 struct kvm_s390_apcb0 tmp;
143
144 if (read_guest_real(vcpu, apcb_o, &tmp, sizeof(struct kvm_s390_apcb0)))
145 return -EFAULT;
146
147 apcb_s->apm[0] = apcb_h->apm[0] & tmp.apm[0];
148 apcb_s->aqm[0] = apcb_h->aqm[0] & tmp.aqm[0] & 0xffff000000000000UL;
149 apcb_s->adm[0] = apcb_h->adm[0] & tmp.adm[0] & 0xffff000000000000UL;
150
151 return 0;
152
153}
154
155/**
156 * setup_apcb00 - Copy to APCB FORMAT0 from APCB FORMAT0
157 * @vcpu: pointer to the virtual CPU
158 * @apcb_s: pointer to start of apcb in the shadow crycb
159 * @apcb_o: pointer to start of original apcb in the guest2
160 * @apcb_h: pointer to start of apcb in the guest1
161 *
162 * Returns 0 and -EFAULT on error reading guest apcb
163 */
164static int setup_apcb00(struct kvm_vcpu *vcpu, unsigned long *apcb_s,
165 unsigned long apcb_o, unsigned long *apcb_h)
166{
167 if (read_guest_real(vcpu, apcb_o, apcb_s,
168 sizeof(struct kvm_s390_apcb0)))
169 return -EFAULT;
170
171 bitmap_and(apcb_s, apcb_s, apcb_h, sizeof(struct kvm_s390_apcb0));
172
173 return 0;
174}
175
176/**
177 * setup_apcb11 - Copy the FORMAT1 APCB from the guest to the shadow CRYCB
178 * @vcpu: pointer to the virtual CPU
179 * @apcb_s: pointer to start of apcb in the shadow crycb
180 * @apcb_o: pointer to start of original guest apcb
181 * @apcb_h: pointer to start of apcb in the host
182 *
183 * Returns 0 and -EFAULT on error reading guest apcb
184 */
185static int setup_apcb11(struct kvm_vcpu *vcpu, unsigned long *apcb_s,
186 unsigned long apcb_o,
187 unsigned long *apcb_h)
188{
189 if (read_guest_real(vcpu, apcb_o, apcb_s,
190 sizeof(struct kvm_s390_apcb1)))
191 return -EFAULT;
192
193 bitmap_and(apcb_s, apcb_s, apcb_h, sizeof(struct kvm_s390_apcb1));
194
195 return 0;
196}
197
198/**
199 * setup_apcb - Create a shadow copy of the apcb.
200 * @vcpu: pointer to the virtual CPU
201 * @crycb_s: pointer to shadow crycb
202 * @crycb_o: pointer to original guest crycb
203 * @crycb_h: pointer to the host crycb
204 * @fmt_o: format of the original guest crycb.
205 * @fmt_h: format of the host crycb.
206 *
207 * Checks the compatibility between the guest and host crycb and calls the
208 * appropriate copy function.
209 *
210 * Return 0 or an error number if the guest and host crycb are incompatible.
211 */
212static int setup_apcb(struct kvm_vcpu *vcpu, struct kvm_s390_crypto_cb *crycb_s,
213 const u32 crycb_o,
214 struct kvm_s390_crypto_cb *crycb_h,
215 int fmt_o, int fmt_h)
216{
217 struct kvm_s390_crypto_cb *crycb;
218
219 crycb = (struct kvm_s390_crypto_cb *) (unsigned long)crycb_o;
220
221 switch (fmt_o) {
222 case CRYCB_FORMAT2:
223 if ((crycb_o & PAGE_MASK) != ((crycb_o + 256) & PAGE_MASK))
224 return -EACCES;
225 if (fmt_h != CRYCB_FORMAT2)
226 return -EINVAL;
227 return setup_apcb11(vcpu, (unsigned long *)&crycb_s->apcb1,
228 (unsigned long) &crycb->apcb1,
229 (unsigned long *)&crycb_h->apcb1);
230 case CRYCB_FORMAT1:
231 switch (fmt_h) {
232 case CRYCB_FORMAT2:
233 return setup_apcb10(vcpu, &crycb_s->apcb1,
234 (unsigned long) &crycb->apcb0,
235 &crycb_h->apcb1);
236 case CRYCB_FORMAT1:
237 return setup_apcb00(vcpu,
238 (unsigned long *) &crycb_s->apcb0,
239 (unsigned long) &crycb->apcb0,
240 (unsigned long *) &crycb_h->apcb0);
241 }
242 break;
243 case CRYCB_FORMAT0:
244 if ((crycb_o & PAGE_MASK) != ((crycb_o + 32) & PAGE_MASK))
245 return -EACCES;
246
247 switch (fmt_h) {
248 case CRYCB_FORMAT2:
249 return setup_apcb10(vcpu, &crycb_s->apcb1,
250 (unsigned long) &crycb->apcb0,
251 &crycb_h->apcb1);
252 case CRYCB_FORMAT1:
253 case CRYCB_FORMAT0:
254 return setup_apcb00(vcpu,
255 (unsigned long *) &crycb_s->apcb0,
256 (unsigned long) &crycb->apcb0,
257 (unsigned long *) &crycb_h->apcb0);
258 }
259 }
260 return -EINVAL;
261}
262
263/**
264 * shadow_crycb - Create a shadow copy of the crycb block
265 * @vcpu: a pointer to the virtual CPU
266 * @vsie_page: a pointer to internal date used for the vSIE
267 *
268 * Create a shadow copy of the crycb block and setup key wrapping, if
269 * requested for guest 3 and enabled for guest 2.
270 *
271 * We accept format-1 or format-2, but we convert format-1 into format-2
272 * in the shadow CRYCB.
273 * Using format-2 enables the firmware to choose the right format when
274 * scheduling the SIE.
275 * There is nothing to do for format-0.
276 *
277 * This function centralize the issuing of set_validity_icpt() for all
278 * the subfunctions working on the crycb.
279 *
280 * Returns: - 0 if shadowed or nothing to do
281 * - > 0 if control has to be given to guest 2
282 */
283static int shadow_crycb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
284{
285 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
286 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
287 const uint32_t crycbd_o = READ_ONCE(scb_o->crycbd);
288 const u32 crycb_addr = crycbd_o & 0x7ffffff8U;
289 unsigned long *b1, *b2;
290 u8 ecb3_flags;
291 u32 ecd_flags;
292 int apie_h;
293 int apie_s;
294 int key_msk = test_kvm_facility(vcpu->kvm, 76);
295 int fmt_o = crycbd_o & CRYCB_FORMAT_MASK;
296 int fmt_h = vcpu->arch.sie_block->crycbd & CRYCB_FORMAT_MASK;
297 int ret = 0;
298
299 scb_s->crycbd = 0;
300
301 apie_h = vcpu->arch.sie_block->eca & ECA_APIE;
302 apie_s = apie_h & scb_o->eca;
303 if (!apie_s && (!key_msk || (fmt_o == CRYCB_FORMAT0)))
304 return 0;
305
306 if (!crycb_addr)
307 return set_validity_icpt(scb_s, 0x0039U);
308
309 if (fmt_o == CRYCB_FORMAT1)
310 if ((crycb_addr & PAGE_MASK) !=
311 ((crycb_addr + 128) & PAGE_MASK))
312 return set_validity_icpt(scb_s, 0x003CU);
313
314 if (apie_s) {
315 ret = setup_apcb(vcpu, &vsie_page->crycb, crycb_addr,
316 vcpu->kvm->arch.crypto.crycb,
317 fmt_o, fmt_h);
318 if (ret)
319 goto end;
320 scb_s->eca |= scb_o->eca & ECA_APIE;
321 }
322
323 /* we may only allow it if enabled for guest 2 */
324 ecb3_flags = scb_o->ecb3 & vcpu->arch.sie_block->ecb3 &
325 (ECB3_AES | ECB3_DEA);
326 ecd_flags = scb_o->ecd & vcpu->arch.sie_block->ecd & ECD_ECC;
327 if (!ecb3_flags && !ecd_flags)
328 goto end;
329
330 /* copy only the wrapping keys */
331 if (read_guest_real(vcpu, crycb_addr + 72,
332 vsie_page->crycb.dea_wrapping_key_mask, 56))
333 return set_validity_icpt(scb_s, 0x0035U);
334
335 scb_s->ecb3 |= ecb3_flags;
336 scb_s->ecd |= ecd_flags;
337
338 /* xor both blocks in one run */
339 b1 = (unsigned long *) vsie_page->crycb.dea_wrapping_key_mask;
340 b2 = (unsigned long *)
341 vcpu->kvm->arch.crypto.crycb->dea_wrapping_key_mask;
342 /* as 56%8 == 0, bitmap_xor won't overwrite any data */
343 bitmap_xor(b1, b1, b2, BITS_PER_BYTE * 56);
344end:
345 switch (ret) {
346 case -EINVAL:
347 return set_validity_icpt(scb_s, 0x0022U);
348 case -EFAULT:
349 return set_validity_icpt(scb_s, 0x0035U);
350 case -EACCES:
351 return set_validity_icpt(scb_s, 0x003CU);
352 }
353 scb_s->crycbd = ((__u32)(__u64) &vsie_page->crycb) | CRYCB_FORMAT2;
354 return 0;
355}
356
357/* shadow (round up/down) the ibc to avoid validity icpt */
358static void prepare_ibc(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
359{
360 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
361 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
362 /* READ_ONCE does not work on bitfields - use a temporary variable */
363 const uint32_t __new_ibc = scb_o->ibc;
364 const uint32_t new_ibc = READ_ONCE(__new_ibc) & 0x0fffU;
365 __u64 min_ibc = (sclp.ibc >> 16) & 0x0fffU;
366
367 scb_s->ibc = 0;
368 /* ibc installed in g2 and requested for g3 */
369 if (vcpu->kvm->arch.model.ibc && new_ibc) {
370 scb_s->ibc = new_ibc;
371 /* takte care of the minimum ibc level of the machine */
372 if (scb_s->ibc < min_ibc)
373 scb_s->ibc = min_ibc;
374 /* take care of the maximum ibc level set for the guest */
375 if (scb_s->ibc > vcpu->kvm->arch.model.ibc)
376 scb_s->ibc = vcpu->kvm->arch.model.ibc;
377 }
378}
379
380/* unshadow the scb, copying parameters back to the real scb */
381static void unshadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
382{
383 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
384 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
385
386 /* interception */
387 scb_o->icptcode = scb_s->icptcode;
388 scb_o->icptstatus = scb_s->icptstatus;
389 scb_o->ipa = scb_s->ipa;
390 scb_o->ipb = scb_s->ipb;
391 scb_o->gbea = scb_s->gbea;
392
393 /* timer */
394 scb_o->cputm = scb_s->cputm;
395 scb_o->ckc = scb_s->ckc;
396 scb_o->todpr = scb_s->todpr;
397
398 /* guest state */
399 scb_o->gpsw = scb_s->gpsw;
400 scb_o->gg14 = scb_s->gg14;
401 scb_o->gg15 = scb_s->gg15;
402 memcpy(scb_o->gcr, scb_s->gcr, 128);
403 scb_o->pp = scb_s->pp;
404
405 /* branch prediction */
406 if (test_kvm_facility(vcpu->kvm, 82)) {
407 scb_o->fpf &= ~FPF_BPBC;
408 scb_o->fpf |= scb_s->fpf & FPF_BPBC;
409 }
410
411 /* interrupt intercept */
412 switch (scb_s->icptcode) {
413 case ICPT_PROGI:
414 case ICPT_INSTPROGI:
415 case ICPT_EXTINT:
416 memcpy((void *)((u64)scb_o + 0xc0),
417 (void *)((u64)scb_s + 0xc0), 0xf0 - 0xc0);
418 break;
419 case ICPT_PARTEXEC:
420 /* MVPG only */
421 memcpy((void *)((u64)scb_o + 0xc0),
422 (void *)((u64)scb_s + 0xc0), 0xd0 - 0xc0);
423 break;
424 }
425
426 if (scb_s->ihcpu != 0xffffU)
427 scb_o->ihcpu = scb_s->ihcpu;
428}
429
430/*
431 * Setup the shadow scb by copying and checking the relevant parts of the g2
432 * provided scb.
433 *
434 * Returns: - 0 if the scb has been shadowed
435 * - > 0 if control has to be given to guest 2
436 */
437static int shadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
438{
439 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
440 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
441 /* READ_ONCE does not work on bitfields - use a temporary variable */
442 const uint32_t __new_prefix = scb_o->prefix;
443 const uint32_t new_prefix = READ_ONCE(__new_prefix);
444 const bool wants_tx = READ_ONCE(scb_o->ecb) & ECB_TE;
445 bool had_tx = scb_s->ecb & ECB_TE;
446 unsigned long new_mso = 0;
447 int rc;
448
449 /* make sure we don't have any leftovers when reusing the scb */
450 scb_s->icptcode = 0;
451 scb_s->eca = 0;
452 scb_s->ecb = 0;
453 scb_s->ecb2 = 0;
454 scb_s->ecb3 = 0;
455 scb_s->ecd = 0;
456 scb_s->fac = 0;
457 scb_s->fpf = 0;
458
459 rc = prepare_cpuflags(vcpu, vsie_page);
460 if (rc)
461 goto out;
462
463 /* timer */
464 scb_s->cputm = scb_o->cputm;
465 scb_s->ckc = scb_o->ckc;
466 scb_s->todpr = scb_o->todpr;
467 scb_s->epoch = scb_o->epoch;
468
469 /* guest state */
470 scb_s->gpsw = scb_o->gpsw;
471 scb_s->gg14 = scb_o->gg14;
472 scb_s->gg15 = scb_o->gg15;
473 memcpy(scb_s->gcr, scb_o->gcr, 128);
474 scb_s->pp = scb_o->pp;
475
476 /* interception / execution handling */
477 scb_s->gbea = scb_o->gbea;
478 scb_s->lctl = scb_o->lctl;
479 scb_s->svcc = scb_o->svcc;
480 scb_s->ictl = scb_o->ictl;
481 /*
482 * SKEY handling functions can't deal with false setting of PTE invalid
483 * bits. Therefore we cannot provide interpretation and would later
484 * have to provide own emulation handlers.
485 */
486 if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_KSS))
487 scb_s->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE;
488
489 scb_s->icpua = scb_o->icpua;
490
491 if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_SM))
492 new_mso = READ_ONCE(scb_o->mso) & 0xfffffffffff00000UL;
493 /* if the hva of the prefix changes, we have to remap the prefix */
494 if (scb_s->mso != new_mso || scb_s->prefix != new_prefix)
495 prefix_unmapped(vsie_page);
496 /* SIE will do mso/msl validity and exception checks for us */
497 scb_s->msl = scb_o->msl & 0xfffffffffff00000UL;
498 scb_s->mso = new_mso;
499 scb_s->prefix = new_prefix;
500
501 /* We have to definetly flush the tlb if this scb never ran */
502 if (scb_s->ihcpu != 0xffffU)
503 scb_s->ihcpu = scb_o->ihcpu;
504
505 /* MVPG and Protection Exception Interpretation are always available */
506 scb_s->eca |= scb_o->eca & (ECA_MVPGI | ECA_PROTEXCI);
507 /* Host-protection-interruption introduced with ESOP */
508 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_ESOP))
509 scb_s->ecb |= scb_o->ecb & ECB_HOSTPROTINT;
510 /* transactional execution */
511 if (test_kvm_facility(vcpu->kvm, 73) && wants_tx) {
512 /* remap the prefix is tx is toggled on */
513 if (!had_tx)
514 prefix_unmapped(vsie_page);
515 scb_s->ecb |= ECB_TE;
516 }
517 /* branch prediction */
518 if (test_kvm_facility(vcpu->kvm, 82))
519 scb_s->fpf |= scb_o->fpf & FPF_BPBC;
520 /* SIMD */
521 if (test_kvm_facility(vcpu->kvm, 129)) {
522 scb_s->eca |= scb_o->eca & ECA_VX;
523 scb_s->ecd |= scb_o->ecd & ECD_HOSTREGMGMT;
524 }
525 /* Run-time-Instrumentation */
526 if (test_kvm_facility(vcpu->kvm, 64))
527 scb_s->ecb3 |= scb_o->ecb3 & ECB3_RI;
528 /* Instruction Execution Prevention */
529 if (test_kvm_facility(vcpu->kvm, 130))
530 scb_s->ecb2 |= scb_o->ecb2 & ECB2_IEP;
531 /* Guarded Storage */
532 if (test_kvm_facility(vcpu->kvm, 133)) {
533 scb_s->ecb |= scb_o->ecb & ECB_GS;
534 scb_s->ecd |= scb_o->ecd & ECD_HOSTREGMGMT;
535 }
536 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_SIIF))
537 scb_s->eca |= scb_o->eca & ECA_SII;
538 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_IB))
539 scb_s->eca |= scb_o->eca & ECA_IB;
540 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_CEI))
541 scb_s->eca |= scb_o->eca & ECA_CEI;
542 /* Epoch Extension */
543 if (test_kvm_facility(vcpu->kvm, 139))
544 scb_s->ecd |= scb_o->ecd & ECD_MEF;
545
546 /* etoken */
547 if (test_kvm_facility(vcpu->kvm, 156))
548 scb_s->ecd |= scb_o->ecd & ECD_ETOKENF;
549
550 scb_s->hpid = HPID_VSIE;
551
552 prepare_ibc(vcpu, vsie_page);
553 rc = shadow_crycb(vcpu, vsie_page);
554out:
555 if (rc)
556 unshadow_scb(vcpu, vsie_page);
557 return rc;
558}
559
560void kvm_s390_vsie_gmap_notifier(struct gmap *gmap, unsigned long start,
561 unsigned long end)
562{
563 struct kvm *kvm = gmap->private;
564 struct vsie_page *cur;
565 unsigned long prefix;
566 struct page *page;
567 int i;
568
569 if (!gmap_is_shadow(gmap))
570 return;
571 if (start >= 1UL << 31)
572 /* We are only interested in prefix pages */
573 return;
574
575 /*
576 * Only new shadow blocks are added to the list during runtime,
577 * therefore we can safely reference them all the time.
578 */
579 for (i = 0; i < kvm->arch.vsie.page_count; i++) {
580 page = READ_ONCE(kvm->arch.vsie.pages[i]);
581 if (!page)
582 continue;
583 cur = page_to_virt(page);
584 if (READ_ONCE(cur->gmap) != gmap)
585 continue;
586 prefix = cur->scb_s.prefix << GUEST_PREFIX_SHIFT;
587 /* with mso/msl, the prefix lies at an offset */
588 prefix += cur->scb_s.mso;
589 if (prefix <= end && start <= prefix + 2 * PAGE_SIZE - 1)
590 prefix_unmapped_sync(cur);
591 }
592}
593
594/*
595 * Map the first prefix page and if tx is enabled also the second prefix page.
596 *
597 * The prefix will be protected, a gmap notifier will inform about unmaps.
598 * The shadow scb must not be executed until the prefix is remapped, this is
599 * guaranteed by properly handling PROG_REQUEST.
600 *
601 * Returns: - 0 on if successfully mapped or already mapped
602 * - > 0 if control has to be given to guest 2
603 * - -EAGAIN if the caller can retry immediately
604 * - -ENOMEM if out of memory
605 */
606static int map_prefix(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
607{
608 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
609 u64 prefix = scb_s->prefix << GUEST_PREFIX_SHIFT;
610 int rc;
611
612 if (prefix_is_mapped(vsie_page))
613 return 0;
614
615 /* mark it as mapped so we can catch any concurrent unmappers */
616 prefix_mapped(vsie_page);
617
618 /* with mso/msl, the prefix lies at offset *mso* */
619 prefix += scb_s->mso;
620
621 rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, prefix);
622 if (!rc && (scb_s->ecb & ECB_TE))
623 rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap,
624 prefix + PAGE_SIZE);
625 /*
626 * We don't have to mprotect, we will be called for all unshadows.
627 * SIE will detect if protection applies and trigger a validity.
628 */
629 if (rc)
630 prefix_unmapped(vsie_page);
631 if (rc > 0 || rc == -EFAULT)
632 rc = set_validity_icpt(scb_s, 0x0037U);
633 return rc;
634}
635
636/*
637 * Pin the guest page given by gpa and set hpa to the pinned host address.
638 * Will always be pinned writable.
639 *
640 * Returns: - 0 on success
641 * - -EINVAL if the gpa is not valid guest storage
642 */
643static int pin_guest_page(struct kvm *kvm, gpa_t gpa, hpa_t *hpa)
644{
645 struct page *page;
646
647 page = gfn_to_page(kvm, gpa_to_gfn(gpa));
648 if (is_error_page(page))
649 return -EINVAL;
650 *hpa = (hpa_t) page_to_virt(page) + (gpa & ~PAGE_MASK);
651 return 0;
652}
653
654/* Unpins a page previously pinned via pin_guest_page, marking it as dirty. */
655static void unpin_guest_page(struct kvm *kvm, gpa_t gpa, hpa_t hpa)
656{
657 kvm_release_pfn_dirty(hpa >> PAGE_SHIFT);
658 /* mark the page always as dirty for migration */
659 mark_page_dirty(kvm, gpa_to_gfn(gpa));
660}
661
662/* unpin all blocks previously pinned by pin_blocks(), marking them dirty */
663static void unpin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
664{
665 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
666 hpa_t hpa;
667
668 hpa = (u64) scb_s->scaoh << 32 | scb_s->scaol;
669 if (hpa) {
670 unpin_guest_page(vcpu->kvm, vsie_page->sca_gpa, hpa);
671 vsie_page->sca_gpa = 0;
672 scb_s->scaol = 0;
673 scb_s->scaoh = 0;
674 }
675
676 hpa = scb_s->itdba;
677 if (hpa) {
678 unpin_guest_page(vcpu->kvm, vsie_page->itdba_gpa, hpa);
679 vsie_page->itdba_gpa = 0;
680 scb_s->itdba = 0;
681 }
682
683 hpa = scb_s->gvrd;
684 if (hpa) {
685 unpin_guest_page(vcpu->kvm, vsie_page->gvrd_gpa, hpa);
686 vsie_page->gvrd_gpa = 0;
687 scb_s->gvrd = 0;
688 }
689
690 hpa = scb_s->riccbd;
691 if (hpa) {
692 unpin_guest_page(vcpu->kvm, vsie_page->riccbd_gpa, hpa);
693 vsie_page->riccbd_gpa = 0;
694 scb_s->riccbd = 0;
695 }
696
697 hpa = scb_s->sdnxo;
698 if (hpa) {
699 unpin_guest_page(vcpu->kvm, vsie_page->sdnx_gpa, hpa);
700 vsie_page->sdnx_gpa = 0;
701 scb_s->sdnxo = 0;
702 }
703}
704
705/*
706 * Instead of shadowing some blocks, we can simply forward them because the
707 * addresses in the scb are 64 bit long.
708 *
709 * This works as long as the data lies in one page. If blocks ever exceed one
710 * page, we have to fall back to shadowing.
711 *
712 * As we reuse the sca, the vcpu pointers contained in it are invalid. We must
713 * therefore not enable any facilities that access these pointers (e.g. SIGPIF).
714 *
715 * Returns: - 0 if all blocks were pinned.
716 * - > 0 if control has to be given to guest 2
717 * - -ENOMEM if out of memory
718 */
719static int pin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
720{
721 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
722 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
723 hpa_t hpa;
724 gpa_t gpa;
725 int rc = 0;
726
727 gpa = READ_ONCE(scb_o->scaol) & ~0xfUL;
728 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_64BSCAO))
729 gpa |= (u64) READ_ONCE(scb_o->scaoh) << 32;
730 if (gpa) {
731 if (gpa < 2 * PAGE_SIZE)
732 rc = set_validity_icpt(scb_s, 0x0038U);
733 else if ((gpa & ~0x1fffUL) == kvm_s390_get_prefix(vcpu))
734 rc = set_validity_icpt(scb_s, 0x0011U);
735 else if ((gpa & PAGE_MASK) !=
736 ((gpa + sizeof(struct bsca_block) - 1) & PAGE_MASK))
737 rc = set_validity_icpt(scb_s, 0x003bU);
738 if (!rc) {
739 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
740 if (rc)
741 rc = set_validity_icpt(scb_s, 0x0034U);
742 }
743 if (rc)
744 goto unpin;
745 vsie_page->sca_gpa = gpa;
746 scb_s->scaoh = (u32)((u64)hpa >> 32);
747 scb_s->scaol = (u32)(u64)hpa;
748 }
749
750 gpa = READ_ONCE(scb_o->itdba) & ~0xffUL;
751 if (gpa && (scb_s->ecb & ECB_TE)) {
752 if (gpa < 2 * PAGE_SIZE) {
753 rc = set_validity_icpt(scb_s, 0x0080U);
754 goto unpin;
755 }
756 /* 256 bytes cannot cross page boundaries */
757 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
758 if (rc) {
759 rc = set_validity_icpt(scb_s, 0x0080U);
760 goto unpin;
761 }
762 vsie_page->itdba_gpa = gpa;
763 scb_s->itdba = hpa;
764 }
765
766 gpa = READ_ONCE(scb_o->gvrd) & ~0x1ffUL;
767 if (gpa && (scb_s->eca & ECA_VX) && !(scb_s->ecd & ECD_HOSTREGMGMT)) {
768 if (gpa < 2 * PAGE_SIZE) {
769 rc = set_validity_icpt(scb_s, 0x1310U);
770 goto unpin;
771 }
772 /*
773 * 512 bytes vector registers cannot cross page boundaries
774 * if this block gets bigger, we have to shadow it.
775 */
776 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
777 if (rc) {
778 rc = set_validity_icpt(scb_s, 0x1310U);
779 goto unpin;
780 }
781 vsie_page->gvrd_gpa = gpa;
782 scb_s->gvrd = hpa;
783 }
784
785 gpa = READ_ONCE(scb_o->riccbd) & ~0x3fUL;
786 if (gpa && (scb_s->ecb3 & ECB3_RI)) {
787 if (gpa < 2 * PAGE_SIZE) {
788 rc = set_validity_icpt(scb_s, 0x0043U);
789 goto unpin;
790 }
791 /* 64 bytes cannot cross page boundaries */
792 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
793 if (rc) {
794 rc = set_validity_icpt(scb_s, 0x0043U);
795 goto unpin;
796 }
797 /* Validity 0x0044 will be checked by SIE */
798 vsie_page->riccbd_gpa = gpa;
799 scb_s->riccbd = hpa;
800 }
801 if (((scb_s->ecb & ECB_GS) && !(scb_s->ecd & ECD_HOSTREGMGMT)) ||
802 (scb_s->ecd & ECD_ETOKENF)) {
803 unsigned long sdnxc;
804
805 gpa = READ_ONCE(scb_o->sdnxo) & ~0xfUL;
806 sdnxc = READ_ONCE(scb_o->sdnxo) & 0xfUL;
807 if (!gpa || gpa < 2 * PAGE_SIZE) {
808 rc = set_validity_icpt(scb_s, 0x10b0U);
809 goto unpin;
810 }
811 if (sdnxc < 6 || sdnxc > 12) {
812 rc = set_validity_icpt(scb_s, 0x10b1U);
813 goto unpin;
814 }
815 if (gpa & ((1 << sdnxc) - 1)) {
816 rc = set_validity_icpt(scb_s, 0x10b2U);
817 goto unpin;
818 }
819 /* Due to alignment rules (checked above) this cannot
820 * cross page boundaries
821 */
822 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
823 if (rc) {
824 rc = set_validity_icpt(scb_s, 0x10b0U);
825 goto unpin;
826 }
827 vsie_page->sdnx_gpa = gpa;
828 scb_s->sdnxo = hpa | sdnxc;
829 }
830 return 0;
831unpin:
832 unpin_blocks(vcpu, vsie_page);
833 return rc;
834}
835
836/* unpin the scb provided by guest 2, marking it as dirty */
837static void unpin_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page,
838 gpa_t gpa)
839{
840 hpa_t hpa = (hpa_t) vsie_page->scb_o;
841
842 if (hpa)
843 unpin_guest_page(vcpu->kvm, gpa, hpa);
844 vsie_page->scb_o = NULL;
845}
846
847/*
848 * Pin the scb at gpa provided by guest 2 at vsie_page->scb_o.
849 *
850 * Returns: - 0 if the scb was pinned.
851 * - > 0 if control has to be given to guest 2
852 */
853static int pin_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page,
854 gpa_t gpa)
855{
856 hpa_t hpa;
857 int rc;
858
859 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
860 if (rc) {
861 rc = kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
862 WARN_ON_ONCE(rc);
863 return 1;
864 }
865 vsie_page->scb_o = (struct kvm_s390_sie_block *) hpa;
866 return 0;
867}
868
869/*
870 * Inject a fault into guest 2.
871 *
872 * Returns: - > 0 if control has to be given to guest 2
873 * < 0 if an error occurred during injection.
874 */
875static int inject_fault(struct kvm_vcpu *vcpu, __u16 code, __u64 vaddr,
876 bool write_flag)
877{
878 struct kvm_s390_pgm_info pgm = {
879 .code = code,
880 .trans_exc_code =
881 /* 0-51: virtual address */
882 (vaddr & 0xfffffffffffff000UL) |
883 /* 52-53: store / fetch */
884 (((unsigned int) !write_flag) + 1) << 10,
885 /* 62-63: asce id (alway primary == 0) */
886 .exc_access_id = 0, /* always primary */
887 .op_access_id = 0, /* not MVPG */
888 };
889 int rc;
890
891 if (code == PGM_PROTECTION)
892 pgm.trans_exc_code |= 0x4UL;
893
894 rc = kvm_s390_inject_prog_irq(vcpu, &pgm);
895 return rc ? rc : 1;
896}
897
898/*
899 * Handle a fault during vsie execution on a gmap shadow.
900 *
901 * Returns: - 0 if the fault was resolved
902 * - > 0 if control has to be given to guest 2
903 * - < 0 if an error occurred
904 */
905static int handle_fault(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
906{
907 int rc;
908
909 if (current->thread.gmap_int_code == PGM_PROTECTION)
910 /* we can directly forward all protection exceptions */
911 return inject_fault(vcpu, PGM_PROTECTION,
912 current->thread.gmap_addr, 1);
913
914 rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap,
915 current->thread.gmap_addr);
916 if (rc > 0) {
917 rc = inject_fault(vcpu, rc,
918 current->thread.gmap_addr,
919 current->thread.gmap_write_flag);
920 if (rc >= 0)
921 vsie_page->fault_addr = current->thread.gmap_addr;
922 }
923 return rc;
924}
925
926/*
927 * Retry the previous fault that required guest 2 intervention. This avoids
928 * one superfluous SIE re-entry and direct exit.
929 *
930 * Will ignore any errors. The next SIE fault will do proper fault handling.
931 */
932static void handle_last_fault(struct kvm_vcpu *vcpu,
933 struct vsie_page *vsie_page)
934{
935 if (vsie_page->fault_addr)
936 kvm_s390_shadow_fault(vcpu, vsie_page->gmap,
937 vsie_page->fault_addr);
938 vsie_page->fault_addr = 0;
939}
940
941static inline void clear_vsie_icpt(struct vsie_page *vsie_page)
942{
943 vsie_page->scb_s.icptcode = 0;
944}
945
946/* rewind the psw and clear the vsie icpt, so we can retry execution */
947static void retry_vsie_icpt(struct vsie_page *vsie_page)
948{
949 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
950 int ilen = insn_length(scb_s->ipa >> 8);
951
952 /* take care of EXECUTE instructions */
953 if (scb_s->icptstatus & 1) {
954 ilen = (scb_s->icptstatus >> 4) & 0x6;
955 if (!ilen)
956 ilen = 4;
957 }
958 scb_s->gpsw.addr = __rewind_psw(scb_s->gpsw, ilen);
959 clear_vsie_icpt(vsie_page);
960}
961
962/*
963 * Try to shadow + enable the guest 2 provided facility list.
964 * Retry instruction execution if enabled for and provided by guest 2.
965 *
966 * Returns: - 0 if handled (retry or guest 2 icpt)
967 * - > 0 if control has to be given to guest 2
968 */
969static int handle_stfle(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
970{
971 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
972 __u32 fac = READ_ONCE(vsie_page->scb_o->fac) & 0x7ffffff8U;
973
974 if (fac && test_kvm_facility(vcpu->kvm, 7)) {
975 retry_vsie_icpt(vsie_page);
976 if (read_guest_real(vcpu, fac, &vsie_page->fac,
977 sizeof(vsie_page->fac)))
978 return set_validity_icpt(scb_s, 0x1090U);
979 scb_s->fac = (__u32)(__u64) &vsie_page->fac;
980 }
981 return 0;
982}
983
984/*
985 * Run the vsie on a shadow scb and a shadow gmap, without any further
986 * sanity checks, handling SIE faults.
987 *
988 * Returns: - 0 everything went fine
989 * - > 0 if control has to be given to guest 2
990 * - < 0 if an error occurred
991 */
992static int do_vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
993 __releases(vcpu->kvm->srcu)
994 __acquires(vcpu->kvm->srcu)
995{
996 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
997 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
998 int guest_bp_isolation;
999 int rc = 0;
1000
1001 handle_last_fault(vcpu, vsie_page);
1002
1003 if (need_resched())
1004 schedule();
1005 if (test_cpu_flag(CIF_MCCK_PENDING))
1006 s390_handle_mcck();
1007
1008 srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
1009
1010 /* save current guest state of bp isolation override */
1011 guest_bp_isolation = test_thread_flag(TIF_ISOLATE_BP_GUEST);
1012
1013 /*
1014 * The guest is running with BPBC, so we have to force it on for our
1015 * nested guest. This is done by enabling BPBC globally, so the BPBC
1016 * control in the SCB (which the nested guest can modify) is simply
1017 * ignored.
1018 */
1019 if (test_kvm_facility(vcpu->kvm, 82) &&
1020 vcpu->arch.sie_block->fpf & FPF_BPBC)
1021 set_thread_flag(TIF_ISOLATE_BP_GUEST);
1022
1023 local_irq_disable();
1024 guest_enter_irqoff();
1025 local_irq_enable();
1026
1027 /*
1028 * Simulate a SIE entry of the VCPU (see sie64a), so VCPU blocking
1029 * and VCPU requests also hinder the vSIE from running and lead
1030 * to an immediate exit. kvm_s390_vsie_kick() has to be used to
1031 * also kick the vSIE.
1032 */
1033 vcpu->arch.sie_block->prog0c |= PROG_IN_SIE;
1034 barrier();
1035 if (!kvm_s390_vcpu_sie_inhibited(vcpu))
1036 rc = sie64a(scb_s, vcpu->run->s.regs.gprs);
1037 barrier();
1038 vcpu->arch.sie_block->prog0c &= ~PROG_IN_SIE;
1039
1040 local_irq_disable();
1041 guest_exit_irqoff();
1042 local_irq_enable();
1043
1044 /* restore guest state for bp isolation override */
1045 if (!guest_bp_isolation)
1046 clear_thread_flag(TIF_ISOLATE_BP_GUEST);
1047
1048 vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
1049
1050 if (rc == -EINTR) {
1051 VCPU_EVENT(vcpu, 3, "%s", "machine check");
1052 kvm_s390_reinject_machine_check(vcpu, &vsie_page->mcck_info);
1053 return 0;
1054 }
1055
1056 if (rc > 0)
1057 rc = 0; /* we could still have an icpt */
1058 else if (rc == -EFAULT)
1059 return handle_fault(vcpu, vsie_page);
1060
1061 switch (scb_s->icptcode) {
1062 case ICPT_INST:
1063 if (scb_s->ipa == 0xb2b0)
1064 rc = handle_stfle(vcpu, vsie_page);
1065 break;
1066 case ICPT_STOP:
1067 /* stop not requested by g2 - must have been a kick */
1068 if (!(atomic_read(&scb_o->cpuflags) & CPUSTAT_STOP_INT))
1069 clear_vsie_icpt(vsie_page);
1070 break;
1071 case ICPT_VALIDITY:
1072 if ((scb_s->ipa & 0xf000) != 0xf000)
1073 scb_s->ipa += 0x1000;
1074 break;
1075 }
1076 return rc;
1077}
1078
1079static void release_gmap_shadow(struct vsie_page *vsie_page)
1080{
1081 if (vsie_page->gmap)
1082 gmap_put(vsie_page->gmap);
1083 WRITE_ONCE(vsie_page->gmap, NULL);
1084 prefix_unmapped(vsie_page);
1085}
1086
1087static int acquire_gmap_shadow(struct kvm_vcpu *vcpu,
1088 struct vsie_page *vsie_page)
1089{
1090 unsigned long asce;
1091 union ctlreg0 cr0;
1092 struct gmap *gmap;
1093 int edat;
1094
1095 asce = vcpu->arch.sie_block->gcr[1];
1096 cr0.val = vcpu->arch.sie_block->gcr[0];
1097 edat = cr0.edat && test_kvm_facility(vcpu->kvm, 8);
1098 edat += edat && test_kvm_facility(vcpu->kvm, 78);
1099
1100 /*
1101 * ASCE or EDAT could have changed since last icpt, or the gmap
1102 * we're holding has been unshadowed. If the gmap is still valid,
1103 * we can safely reuse it.
1104 */
1105 if (vsie_page->gmap && gmap_shadow_valid(vsie_page->gmap, asce, edat))
1106 return 0;
1107
1108 /* release the old shadow - if any, and mark the prefix as unmapped */
1109 release_gmap_shadow(vsie_page);
1110 gmap = gmap_shadow(vcpu->arch.gmap, asce, edat);
1111 if (IS_ERR(gmap))
1112 return PTR_ERR(gmap);
1113 gmap->private = vcpu->kvm;
1114 WRITE_ONCE(vsie_page->gmap, gmap);
1115 return 0;
1116}
1117
1118/*
1119 * Register the shadow scb at the VCPU, e.g. for kicking out of vsie.
1120 */
1121static void register_shadow_scb(struct kvm_vcpu *vcpu,
1122 struct vsie_page *vsie_page)
1123{
1124 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
1125
1126 WRITE_ONCE(vcpu->arch.vsie_block, &vsie_page->scb_s);
1127 /*
1128 * External calls have to lead to a kick of the vcpu and
1129 * therefore the vsie -> Simulate Wait state.
1130 */
1131 kvm_s390_set_cpuflags(vcpu, CPUSTAT_WAIT);
1132 /*
1133 * We have to adjust the g3 epoch by the g2 epoch. The epoch will
1134 * automatically be adjusted on tod clock changes via kvm_sync_clock.
1135 */
1136 preempt_disable();
1137 scb_s->epoch += vcpu->kvm->arch.epoch;
1138
1139 if (scb_s->ecd & ECD_MEF) {
1140 scb_s->epdx += vcpu->kvm->arch.epdx;
1141 if (scb_s->epoch < vcpu->kvm->arch.epoch)
1142 scb_s->epdx += 1;
1143 }
1144
1145 preempt_enable();
1146}
1147
1148/*
1149 * Unregister a shadow scb from a VCPU.
1150 */
1151static void unregister_shadow_scb(struct kvm_vcpu *vcpu)
1152{
1153 kvm_s390_clear_cpuflags(vcpu, CPUSTAT_WAIT);
1154 WRITE_ONCE(vcpu->arch.vsie_block, NULL);
1155}
1156
1157/*
1158 * Run the vsie on a shadowed scb, managing the gmap shadow, handling
1159 * prefix pages and faults.
1160 *
1161 * Returns: - 0 if no errors occurred
1162 * - > 0 if control has to be given to guest 2
1163 * - -ENOMEM if out of memory
1164 */
1165static int vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
1166{
1167 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
1168 int rc = 0;
1169
1170 while (1) {
1171 rc = acquire_gmap_shadow(vcpu, vsie_page);
1172 if (!rc)
1173 rc = map_prefix(vcpu, vsie_page);
1174 if (!rc) {
1175 gmap_enable(vsie_page->gmap);
1176 update_intervention_requests(vsie_page);
1177 rc = do_vsie_run(vcpu, vsie_page);
1178 gmap_enable(vcpu->arch.gmap);
1179 }
1180 atomic_andnot(PROG_BLOCK_SIE, &scb_s->prog20);
1181
1182 if (rc == -EAGAIN)
1183 rc = 0;
1184 if (rc || scb_s->icptcode || signal_pending(current) ||
1185 kvm_s390_vcpu_has_irq(vcpu, 0) ||
1186 kvm_s390_vcpu_sie_inhibited(vcpu))
1187 break;
1188 }
1189
1190 if (rc == -EFAULT) {
1191 /*
1192 * Addressing exceptions are always presentes as intercepts.
1193 * As addressing exceptions are suppressing and our guest 3 PSW
1194 * points at the responsible instruction, we have to
1195 * forward the PSW and set the ilc. If we can't read guest 3
1196 * instruction, we can use an arbitrary ilc. Let's always use
1197 * ilen = 4 for now, so we can avoid reading in guest 3 virtual
1198 * memory. (we could also fake the shadow so the hardware
1199 * handles it).
1200 */
1201 scb_s->icptcode = ICPT_PROGI;
1202 scb_s->iprcc = PGM_ADDRESSING;
1203 scb_s->pgmilc = 4;
1204 scb_s->gpsw.addr = __rewind_psw(scb_s->gpsw, 4);
1205 }
1206 return rc;
1207}
1208
1209/*
1210 * Get or create a vsie page for a scb address.
1211 *
1212 * Returns: - address of a vsie page (cached or new one)
1213 * - NULL if the same scb address is already used by another VCPU
1214 * - ERR_PTR(-ENOMEM) if out of memory
1215 */
1216static struct vsie_page *get_vsie_page(struct kvm *kvm, unsigned long addr)
1217{
1218 struct vsie_page *vsie_page;
1219 struct page *page;
1220 int nr_vcpus;
1221
1222 rcu_read_lock();
1223 page = radix_tree_lookup(&kvm->arch.vsie.addr_to_page, addr >> 9);
1224 rcu_read_unlock();
1225 if (page) {
1226 if (page_ref_inc_return(page) == 2)
1227 return page_to_virt(page);
1228 page_ref_dec(page);
1229 }
1230
1231 /*
1232 * We want at least #online_vcpus shadows, so every VCPU can execute
1233 * the VSIE in parallel.
1234 */
1235 nr_vcpus = atomic_read(&kvm->online_vcpus);
1236
1237 mutex_lock(&kvm->arch.vsie.mutex);
1238 if (kvm->arch.vsie.page_count < nr_vcpus) {
1239 page = alloc_page(GFP_KERNEL | __GFP_ZERO | GFP_DMA);
1240 if (!page) {
1241 mutex_unlock(&kvm->arch.vsie.mutex);
1242 return ERR_PTR(-ENOMEM);
1243 }
1244 page_ref_inc(page);
1245 kvm->arch.vsie.pages[kvm->arch.vsie.page_count] = page;
1246 kvm->arch.vsie.page_count++;
1247 } else {
1248 /* reuse an existing entry that belongs to nobody */
1249 while (true) {
1250 page = kvm->arch.vsie.pages[kvm->arch.vsie.next];
1251 if (page_ref_inc_return(page) == 2)
1252 break;
1253 page_ref_dec(page);
1254 kvm->arch.vsie.next++;
1255 kvm->arch.vsie.next %= nr_vcpus;
1256 }
1257 radix_tree_delete(&kvm->arch.vsie.addr_to_page, page->index >> 9);
1258 }
1259 page->index = addr;
1260 /* double use of the same address */
1261 if (radix_tree_insert(&kvm->arch.vsie.addr_to_page, addr >> 9, page)) {
1262 page_ref_dec(page);
1263 mutex_unlock(&kvm->arch.vsie.mutex);
1264 return NULL;
1265 }
1266 mutex_unlock(&kvm->arch.vsie.mutex);
1267
1268 vsie_page = page_to_virt(page);
1269 memset(&vsie_page->scb_s, 0, sizeof(struct kvm_s390_sie_block));
1270 release_gmap_shadow(vsie_page);
1271 vsie_page->fault_addr = 0;
1272 vsie_page->scb_s.ihcpu = 0xffffU;
1273 return vsie_page;
1274}
1275
1276/* put a vsie page acquired via get_vsie_page */
1277static void put_vsie_page(struct kvm *kvm, struct vsie_page *vsie_page)
1278{
1279 struct page *page = pfn_to_page(__pa(vsie_page) >> PAGE_SHIFT);
1280
1281 page_ref_dec(page);
1282}
1283
1284int kvm_s390_handle_vsie(struct kvm_vcpu *vcpu)
1285{
1286 struct vsie_page *vsie_page;
1287 unsigned long scb_addr;
1288 int rc;
1289
1290 vcpu->stat.instruction_sie++;
1291 if (!test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_SIEF2))
1292 return -EOPNOTSUPP;
1293 if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
1294 return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
1295
1296 BUILD_BUG_ON(sizeof(struct vsie_page) != PAGE_SIZE);
1297 scb_addr = kvm_s390_get_base_disp_s(vcpu, NULL);
1298
1299 /* 512 byte alignment */
1300 if (unlikely(scb_addr & 0x1ffUL))
1301 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
1302
1303 if (signal_pending(current) || kvm_s390_vcpu_has_irq(vcpu, 0) ||
1304 kvm_s390_vcpu_sie_inhibited(vcpu))
1305 return 0;
1306
1307 vsie_page = get_vsie_page(vcpu->kvm, scb_addr);
1308 if (IS_ERR(vsie_page))
1309 return PTR_ERR(vsie_page);
1310 else if (!vsie_page)
1311 /* double use of sie control block - simply do nothing */
1312 return 0;
1313
1314 rc = pin_scb(vcpu, vsie_page, scb_addr);
1315 if (rc)
1316 goto out_put;
1317 rc = shadow_scb(vcpu, vsie_page);
1318 if (rc)
1319 goto out_unpin_scb;
1320 rc = pin_blocks(vcpu, vsie_page);
1321 if (rc)
1322 goto out_unshadow;
1323 register_shadow_scb(vcpu, vsie_page);
1324 rc = vsie_run(vcpu, vsie_page);
1325 unregister_shadow_scb(vcpu);
1326 unpin_blocks(vcpu, vsie_page);
1327out_unshadow:
1328 unshadow_scb(vcpu, vsie_page);
1329out_unpin_scb:
1330 unpin_scb(vcpu, vsie_page, scb_addr);
1331out_put:
1332 put_vsie_page(vcpu->kvm, vsie_page);
1333
1334 return rc < 0 ? rc : 0;
1335}
1336
1337/* Init the vsie data structures. To be called when a vm is initialized. */
1338void kvm_s390_vsie_init(struct kvm *kvm)
1339{
1340 mutex_init(&kvm->arch.vsie.mutex);
1341 INIT_RADIX_TREE(&kvm->arch.vsie.addr_to_page, GFP_KERNEL);
1342}
1343
1344/* Destroy the vsie data structures. To be called when a vm is destroyed. */
1345void kvm_s390_vsie_destroy(struct kvm *kvm)
1346{
1347 struct vsie_page *vsie_page;
1348 struct page *page;
1349 int i;
1350
1351 mutex_lock(&kvm->arch.vsie.mutex);
1352 for (i = 0; i < kvm->arch.vsie.page_count; i++) {
1353 page = kvm->arch.vsie.pages[i];
1354 kvm->arch.vsie.pages[i] = NULL;
1355 vsie_page = page_to_virt(page);
1356 release_gmap_shadow(vsie_page);
1357 /* free the radix tree entry */
1358 radix_tree_delete(&kvm->arch.vsie.addr_to_page, page->index >> 9);
1359 __free_page(page);
1360 }
1361 kvm->arch.vsie.page_count = 0;
1362 mutex_unlock(&kvm->arch.vsie.mutex);
1363}
1364
1365void kvm_s390_vsie_kick(struct kvm_vcpu *vcpu)
1366{
1367 struct kvm_s390_sie_block *scb = READ_ONCE(vcpu->arch.vsie_block);
1368
1369 /*
1370 * Even if the VCPU lets go of the shadow sie block reference, it is
1371 * still valid in the cache. So we can safely kick it.
1372 */
1373 if (scb) {
1374 atomic_or(PROG_BLOCK_SIE, &scb->prog20);
1375 if (scb->prog0c & PROG_IN_SIE)
1376 atomic_or(CPUSTAT_STOP_INT, &scb->cpuflags);
1377 }
1378}