Loading...
Note: File does not exist in v4.6.
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}