Merge remote-tracking branches 'asoc/fix/msm8916', 'asoc/fix/nau8825', 'asoc/fix...
[sfrench/cifs-2.6.git] / arch / s390 / kvm / vsie.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * kvm nested virtualization support for s390x
4  *
5  * Copyright IBM Corp. 2016
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
24 struct 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         /* the pinned originial scb */
32         struct kvm_s390_sie_block *scb_o;       /* 0x0218 */
33         /* the shadow gmap in use by the vsie_page */
34         struct gmap *gmap;                      /* 0x0220 */
35         /* address of the last reported fault to guest2 */
36         unsigned long fault_addr;               /* 0x0228 */
37         __u8 reserved[0x0700 - 0x0230];         /* 0x0230 */
38         struct kvm_s390_crypto_cb crycb;        /* 0x0700 */
39         __u8 fac[S390_ARCH_FAC_LIST_SIZE_BYTE]; /* 0x0800 */
40 };
41
42 /* trigger a validity icpt for the given scb */
43 static int set_validity_icpt(struct kvm_s390_sie_block *scb,
44                              __u16 reason_code)
45 {
46         scb->ipa = 0x1000;
47         scb->ipb = ((__u32) reason_code) << 16;
48         scb->icptcode = ICPT_VALIDITY;
49         return 1;
50 }
51
52 /* mark the prefix as unmapped, this will block the VSIE */
53 static void prefix_unmapped(struct vsie_page *vsie_page)
54 {
55         atomic_or(PROG_REQUEST, &vsie_page->scb_s.prog20);
56 }
57
58 /* mark the prefix as unmapped and wait until the VSIE has been left */
59 static void prefix_unmapped_sync(struct vsie_page *vsie_page)
60 {
61         prefix_unmapped(vsie_page);
62         if (vsie_page->scb_s.prog0c & PROG_IN_SIE)
63                 atomic_or(CPUSTAT_STOP_INT, &vsie_page->scb_s.cpuflags);
64         while (vsie_page->scb_s.prog0c & PROG_IN_SIE)
65                 cpu_relax();
66 }
67
68 /* mark the prefix as mapped, this will allow the VSIE to run */
69 static void prefix_mapped(struct vsie_page *vsie_page)
70 {
71         atomic_andnot(PROG_REQUEST, &vsie_page->scb_s.prog20);
72 }
73
74 /* test if the prefix is mapped into the gmap shadow */
75 static int prefix_is_mapped(struct vsie_page *vsie_page)
76 {
77         return !(atomic_read(&vsie_page->scb_s.prog20) & PROG_REQUEST);
78 }
79
80 /* copy the updated intervention request bits into the shadow scb */
81 static void update_intervention_requests(struct vsie_page *vsie_page)
82 {
83         const int bits = CPUSTAT_STOP_INT | CPUSTAT_IO_INT | CPUSTAT_EXT_INT;
84         int cpuflags;
85
86         cpuflags = atomic_read(&vsie_page->scb_o->cpuflags);
87         atomic_andnot(bits, &vsie_page->scb_s.cpuflags);
88         atomic_or(cpuflags & bits, &vsie_page->scb_s.cpuflags);
89 }
90
91 /* shadow (filter and validate) the cpuflags  */
92 static int prepare_cpuflags(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
93 {
94         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
95         struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
96         int newflags, cpuflags = atomic_read(&scb_o->cpuflags);
97
98         /* we don't allow ESA/390 guests */
99         if (!(cpuflags & CPUSTAT_ZARCH))
100                 return set_validity_icpt(scb_s, 0x0001U);
101
102         if (cpuflags & (CPUSTAT_RRF | CPUSTAT_MCDS))
103                 return set_validity_icpt(scb_s, 0x0001U);
104         else if (cpuflags & (CPUSTAT_SLSV | CPUSTAT_SLSR))
105                 return set_validity_icpt(scb_s, 0x0007U);
106
107         /* intervention requests will be set later */
108         newflags = CPUSTAT_ZARCH;
109         if (cpuflags & CPUSTAT_GED && test_kvm_facility(vcpu->kvm, 8))
110                 newflags |= CPUSTAT_GED;
111         if (cpuflags & CPUSTAT_GED2 && test_kvm_facility(vcpu->kvm, 78)) {
112                 if (cpuflags & CPUSTAT_GED)
113                         return set_validity_icpt(scb_s, 0x0001U);
114                 newflags |= CPUSTAT_GED2;
115         }
116         if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_GPERE))
117                 newflags |= cpuflags & CPUSTAT_P;
118         if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_GSLS))
119                 newflags |= cpuflags & CPUSTAT_SM;
120         if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_IBS))
121                 newflags |= cpuflags & CPUSTAT_IBS;
122         if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_KSS))
123                 newflags |= cpuflags & CPUSTAT_KSS;
124
125         atomic_set(&scb_s->cpuflags, newflags);
126         return 0;
127 }
128
129 /*
130  * Create a shadow copy of the crycb block and setup key wrapping, if
131  * requested for guest 3 and enabled for guest 2.
132  *
133  * We only accept format-1 (no AP in g2), but convert it into format-2
134  * There is nothing to do for format-0.
135  *
136  * Returns: - 0 if shadowed or nothing to do
137  *          - > 0 if control has to be given to guest 2
138  */
139 static int shadow_crycb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
140 {
141         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
142         struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
143         u32 crycb_addr = scb_o->crycbd & 0x7ffffff8U;
144         unsigned long *b1, *b2;
145         u8 ecb3_flags;
146
147         scb_s->crycbd = 0;
148         if (!(scb_o->crycbd & vcpu->arch.sie_block->crycbd & CRYCB_FORMAT1))
149                 return 0;
150         /* format-1 is supported with message-security-assist extension 3 */
151         if (!test_kvm_facility(vcpu->kvm, 76))
152                 return 0;
153         /* we may only allow it if enabled for guest 2 */
154         ecb3_flags = scb_o->ecb3 & vcpu->arch.sie_block->ecb3 &
155                      (ECB3_AES | ECB3_DEA);
156         if (!ecb3_flags)
157                 return 0;
158
159         if ((crycb_addr & PAGE_MASK) != ((crycb_addr + 128) & PAGE_MASK))
160                 return set_validity_icpt(scb_s, 0x003CU);
161         else if (!crycb_addr)
162                 return set_validity_icpt(scb_s, 0x0039U);
163
164         /* copy only the wrapping keys */
165         if (read_guest_real(vcpu, crycb_addr + 72, &vsie_page->crycb, 56))
166                 return set_validity_icpt(scb_s, 0x0035U);
167
168         scb_s->ecb3 |= ecb3_flags;
169         scb_s->crycbd = ((__u32)(__u64) &vsie_page->crycb) | CRYCB_FORMAT1 |
170                         CRYCB_FORMAT2;
171
172         /* xor both blocks in one run */
173         b1 = (unsigned long *) vsie_page->crycb.dea_wrapping_key_mask;
174         b2 = (unsigned long *)
175                             vcpu->kvm->arch.crypto.crycb->dea_wrapping_key_mask;
176         /* as 56%8 == 0, bitmap_xor won't overwrite any data */
177         bitmap_xor(b1, b1, b2, BITS_PER_BYTE * 56);
178         return 0;
179 }
180
181 /* shadow (round up/down) the ibc to avoid validity icpt */
182 static void prepare_ibc(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
183 {
184         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
185         struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
186         __u64 min_ibc = (sclp.ibc >> 16) & 0x0fffU;
187
188         scb_s->ibc = 0;
189         /* ibc installed in g2 and requested for g3 */
190         if (vcpu->kvm->arch.model.ibc && (scb_o->ibc & 0x0fffU)) {
191                 scb_s->ibc = scb_o->ibc & 0x0fffU;
192                 /* takte care of the minimum ibc level of the machine */
193                 if (scb_s->ibc < min_ibc)
194                         scb_s->ibc = min_ibc;
195                 /* take care of the maximum ibc level set for the guest */
196                 if (scb_s->ibc > vcpu->kvm->arch.model.ibc)
197                         scb_s->ibc = vcpu->kvm->arch.model.ibc;
198         }
199 }
200
201 /* unshadow the scb, copying parameters back to the real scb */
202 static void unshadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
203 {
204         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
205         struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
206
207         /* interception */
208         scb_o->icptcode = scb_s->icptcode;
209         scb_o->icptstatus = scb_s->icptstatus;
210         scb_o->ipa = scb_s->ipa;
211         scb_o->ipb = scb_s->ipb;
212         scb_o->gbea = scb_s->gbea;
213
214         /* timer */
215         scb_o->cputm = scb_s->cputm;
216         scb_o->ckc = scb_s->ckc;
217         scb_o->todpr = scb_s->todpr;
218
219         /* guest state */
220         scb_o->gpsw = scb_s->gpsw;
221         scb_o->gg14 = scb_s->gg14;
222         scb_o->gg15 = scb_s->gg15;
223         memcpy(scb_o->gcr, scb_s->gcr, 128);
224         scb_o->pp = scb_s->pp;
225
226         /* interrupt intercept */
227         switch (scb_s->icptcode) {
228         case ICPT_PROGI:
229         case ICPT_INSTPROGI:
230         case ICPT_EXTINT:
231                 memcpy((void *)((u64)scb_o + 0xc0),
232                        (void *)((u64)scb_s + 0xc0), 0xf0 - 0xc0);
233                 break;
234         case ICPT_PARTEXEC:
235                 /* MVPG only */
236                 memcpy((void *)((u64)scb_o + 0xc0),
237                        (void *)((u64)scb_s + 0xc0), 0xd0 - 0xc0);
238                 break;
239         }
240
241         if (scb_s->ihcpu != 0xffffU)
242                 scb_o->ihcpu = scb_s->ihcpu;
243 }
244
245 /*
246  * Setup the shadow scb by copying and checking the relevant parts of the g2
247  * provided scb.
248  *
249  * Returns: - 0 if the scb has been shadowed
250  *          - > 0 if control has to be given to guest 2
251  */
252 static int shadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
253 {
254         struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
255         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
256         bool had_tx = scb_s->ecb & ECB_TE;
257         unsigned long new_mso = 0;
258         int rc;
259
260         /* make sure we don't have any leftovers when reusing the scb */
261         scb_s->icptcode = 0;
262         scb_s->eca = 0;
263         scb_s->ecb = 0;
264         scb_s->ecb2 = 0;
265         scb_s->ecb3 = 0;
266         scb_s->ecd = 0;
267         scb_s->fac = 0;
268
269         rc = prepare_cpuflags(vcpu, vsie_page);
270         if (rc)
271                 goto out;
272
273         /* timer */
274         scb_s->cputm = scb_o->cputm;
275         scb_s->ckc = scb_o->ckc;
276         scb_s->todpr = scb_o->todpr;
277         scb_s->epoch = scb_o->epoch;
278
279         /* guest state */
280         scb_s->gpsw = scb_o->gpsw;
281         scb_s->gg14 = scb_o->gg14;
282         scb_s->gg15 = scb_o->gg15;
283         memcpy(scb_s->gcr, scb_o->gcr, 128);
284         scb_s->pp = scb_o->pp;
285
286         /* interception / execution handling */
287         scb_s->gbea = scb_o->gbea;
288         scb_s->lctl = scb_o->lctl;
289         scb_s->svcc = scb_o->svcc;
290         scb_s->ictl = scb_o->ictl;
291         /*
292          * SKEY handling functions can't deal with false setting of PTE invalid
293          * bits. Therefore we cannot provide interpretation and would later
294          * have to provide own emulation handlers.
295          */
296         if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_KSS))
297                 scb_s->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE;
298
299         scb_s->icpua = scb_o->icpua;
300
301         if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_SM))
302                 new_mso = scb_o->mso & 0xfffffffffff00000UL;
303         /* if the hva of the prefix changes, we have to remap the prefix */
304         if (scb_s->mso != new_mso || scb_s->prefix != scb_o->prefix)
305                 prefix_unmapped(vsie_page);
306          /* SIE will do mso/msl validity and exception checks for us */
307         scb_s->msl = scb_o->msl & 0xfffffffffff00000UL;
308         scb_s->mso = new_mso;
309         scb_s->prefix = scb_o->prefix;
310
311         /* We have to definetly flush the tlb if this scb never ran */
312         if (scb_s->ihcpu != 0xffffU)
313                 scb_s->ihcpu = scb_o->ihcpu;
314
315         /* MVPG and Protection Exception Interpretation are always available */
316         scb_s->eca |= scb_o->eca & (ECA_MVPGI | ECA_PROTEXCI);
317         /* Host-protection-interruption introduced with ESOP */
318         if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_ESOP))
319                 scb_s->ecb |= scb_o->ecb & ECB_HOSTPROTINT;
320         /* transactional execution */
321         if (test_kvm_facility(vcpu->kvm, 73)) {
322                 /* remap the prefix is tx is toggled on */
323                 if ((scb_o->ecb & ECB_TE) && !had_tx)
324                         prefix_unmapped(vsie_page);
325                 scb_s->ecb |= scb_o->ecb & ECB_TE;
326         }
327         /* SIMD */
328         if (test_kvm_facility(vcpu->kvm, 129)) {
329                 scb_s->eca |= scb_o->eca & ECA_VX;
330                 scb_s->ecd |= scb_o->ecd & ECD_HOSTREGMGMT;
331         }
332         /* Run-time-Instrumentation */
333         if (test_kvm_facility(vcpu->kvm, 64))
334                 scb_s->ecb3 |= scb_o->ecb3 & ECB3_RI;
335         /* Instruction Execution Prevention */
336         if (test_kvm_facility(vcpu->kvm, 130))
337                 scb_s->ecb2 |= scb_o->ecb2 & ECB2_IEP;
338         /* Guarded Storage */
339         if (test_kvm_facility(vcpu->kvm, 133)) {
340                 scb_s->ecb |= scb_o->ecb & ECB_GS;
341                 scb_s->ecd |= scb_o->ecd & ECD_HOSTREGMGMT;
342         }
343         if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_SIIF))
344                 scb_s->eca |= scb_o->eca & ECA_SII;
345         if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_IB))
346                 scb_s->eca |= scb_o->eca & ECA_IB;
347         if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_CEI))
348                 scb_s->eca |= scb_o->eca & ECA_CEI;
349         /* Epoch Extension */
350         if (test_kvm_facility(vcpu->kvm, 139))
351                 scb_s->ecd |= scb_o->ecd & ECD_MEF;
352
353         prepare_ibc(vcpu, vsie_page);
354         rc = shadow_crycb(vcpu, vsie_page);
355 out:
356         if (rc)
357                 unshadow_scb(vcpu, vsie_page);
358         return rc;
359 }
360
361 void kvm_s390_vsie_gmap_notifier(struct gmap *gmap, unsigned long start,
362                                  unsigned long end)
363 {
364         struct kvm *kvm = gmap->private;
365         struct vsie_page *cur;
366         unsigned long prefix;
367         struct page *page;
368         int i;
369
370         if (!gmap_is_shadow(gmap))
371                 return;
372         if (start >= 1UL << 31)
373                 /* We are only interested in prefix pages */
374                 return;
375
376         /*
377          * Only new shadow blocks are added to the list during runtime,
378          * therefore we can safely reference them all the time.
379          */
380         for (i = 0; i < kvm->arch.vsie.page_count; i++) {
381                 page = READ_ONCE(kvm->arch.vsie.pages[i]);
382                 if (!page)
383                         continue;
384                 cur = page_to_virt(page);
385                 if (READ_ONCE(cur->gmap) != gmap)
386                         continue;
387                 prefix = cur->scb_s.prefix << GUEST_PREFIX_SHIFT;
388                 /* with mso/msl, the prefix lies at an offset */
389                 prefix += cur->scb_s.mso;
390                 if (prefix <= end && start <= prefix + 2 * PAGE_SIZE - 1)
391                         prefix_unmapped_sync(cur);
392         }
393 }
394
395 /*
396  * Map the first prefix page and if tx is enabled also the second prefix page.
397  *
398  * The prefix will be protected, a gmap notifier will inform about unmaps.
399  * The shadow scb must not be executed until the prefix is remapped, this is
400  * guaranteed by properly handling PROG_REQUEST.
401  *
402  * Returns: - 0 on if successfully mapped or already mapped
403  *          - > 0 if control has to be given to guest 2
404  *          - -EAGAIN if the caller can retry immediately
405  *          - -ENOMEM if out of memory
406  */
407 static int map_prefix(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
408 {
409         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
410         u64 prefix = scb_s->prefix << GUEST_PREFIX_SHIFT;
411         int rc;
412
413         if (prefix_is_mapped(vsie_page))
414                 return 0;
415
416         /* mark it as mapped so we can catch any concurrent unmappers */
417         prefix_mapped(vsie_page);
418
419         /* with mso/msl, the prefix lies at offset *mso* */
420         prefix += scb_s->mso;
421
422         rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, prefix);
423         if (!rc && (scb_s->ecb & ECB_TE))
424                 rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap,
425                                            prefix + PAGE_SIZE);
426         /*
427          * We don't have to mprotect, we will be called for all unshadows.
428          * SIE will detect if protection applies and trigger a validity.
429          */
430         if (rc)
431                 prefix_unmapped(vsie_page);
432         if (rc > 0 || rc == -EFAULT)
433                 rc = set_validity_icpt(scb_s, 0x0037U);
434         return rc;
435 }
436
437 /*
438  * Pin the guest page given by gpa and set hpa to the pinned host address.
439  * Will always be pinned writable.
440  *
441  * Returns: - 0 on success
442  *          - -EINVAL if the gpa is not valid guest storage
443  */
444 static int pin_guest_page(struct kvm *kvm, gpa_t gpa, hpa_t *hpa)
445 {
446         struct page *page;
447
448         page = gfn_to_page(kvm, gpa_to_gfn(gpa));
449         if (is_error_page(page))
450                 return -EINVAL;
451         *hpa = (hpa_t) page_to_virt(page) + (gpa & ~PAGE_MASK);
452         return 0;
453 }
454
455 /* Unpins a page previously pinned via pin_guest_page, marking it as dirty. */
456 static void unpin_guest_page(struct kvm *kvm, gpa_t gpa, hpa_t hpa)
457 {
458         kvm_release_pfn_dirty(hpa >> PAGE_SHIFT);
459         /* mark the page always as dirty for migration */
460         mark_page_dirty(kvm, gpa_to_gfn(gpa));
461 }
462
463 /* unpin all blocks previously pinned by pin_blocks(), marking them dirty */
464 static void unpin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
465 {
466         struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
467         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
468         hpa_t hpa;
469         gpa_t gpa;
470
471         hpa = (u64) scb_s->scaoh << 32 | scb_s->scaol;
472         if (hpa) {
473                 gpa = scb_o->scaol & ~0xfUL;
474                 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_64BSCAO))
475                         gpa |= (u64) scb_o->scaoh << 32;
476                 unpin_guest_page(vcpu->kvm, gpa, hpa);
477                 scb_s->scaol = 0;
478                 scb_s->scaoh = 0;
479         }
480
481         hpa = scb_s->itdba;
482         if (hpa) {
483                 gpa = scb_o->itdba & ~0xffUL;
484                 unpin_guest_page(vcpu->kvm, gpa, hpa);
485                 scb_s->itdba = 0;
486         }
487
488         hpa = scb_s->gvrd;
489         if (hpa) {
490                 gpa = scb_o->gvrd & ~0x1ffUL;
491                 unpin_guest_page(vcpu->kvm, gpa, hpa);
492                 scb_s->gvrd = 0;
493         }
494
495         hpa = scb_s->riccbd;
496         if (hpa) {
497                 gpa = scb_o->riccbd & ~0x3fUL;
498                 unpin_guest_page(vcpu->kvm, gpa, hpa);
499                 scb_s->riccbd = 0;
500         }
501
502         hpa = scb_s->sdnxo;
503         if (hpa) {
504                 gpa = scb_o->sdnxo;
505                 unpin_guest_page(vcpu->kvm, gpa, hpa);
506                 scb_s->sdnxo = 0;
507         }
508 }
509
510 /*
511  * Instead of shadowing some blocks, we can simply forward them because the
512  * addresses in the scb are 64 bit long.
513  *
514  * This works as long as the data lies in one page. If blocks ever exceed one
515  * page, we have to fall back to shadowing.
516  *
517  * As we reuse the sca, the vcpu pointers contained in it are invalid. We must
518  * therefore not enable any facilities that access these pointers (e.g. SIGPIF).
519  *
520  * Returns: - 0 if all blocks were pinned.
521  *          - > 0 if control has to be given to guest 2
522  *          - -ENOMEM if out of memory
523  */
524 static int pin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
525 {
526         struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
527         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
528         hpa_t hpa;
529         gpa_t gpa;
530         int rc = 0;
531
532         gpa = scb_o->scaol & ~0xfUL;
533         if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_64BSCAO))
534                 gpa |= (u64) scb_o->scaoh << 32;
535         if (gpa) {
536                 if (!(gpa & ~0x1fffUL))
537                         rc = set_validity_icpt(scb_s, 0x0038U);
538                 else if ((gpa & ~0x1fffUL) == kvm_s390_get_prefix(vcpu))
539                         rc = set_validity_icpt(scb_s, 0x0011U);
540                 else if ((gpa & PAGE_MASK) !=
541                          ((gpa + sizeof(struct bsca_block) - 1) & PAGE_MASK))
542                         rc = set_validity_icpt(scb_s, 0x003bU);
543                 if (!rc) {
544                         rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
545                         if (rc)
546                                 rc = set_validity_icpt(scb_s, 0x0034U);
547                 }
548                 if (rc)
549                         goto unpin;
550                 scb_s->scaoh = (u32)((u64)hpa >> 32);
551                 scb_s->scaol = (u32)(u64)hpa;
552         }
553
554         gpa = scb_o->itdba & ~0xffUL;
555         if (gpa && (scb_s->ecb & ECB_TE)) {
556                 if (!(gpa & ~0x1fffU)) {
557                         rc = set_validity_icpt(scb_s, 0x0080U);
558                         goto unpin;
559                 }
560                 /* 256 bytes cannot cross page boundaries */
561                 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
562                 if (rc) {
563                         rc = set_validity_icpt(scb_s, 0x0080U);
564                         goto unpin;
565                 }
566                 scb_s->itdba = hpa;
567         }
568
569         gpa = scb_o->gvrd & ~0x1ffUL;
570         if (gpa && (scb_s->eca & ECA_VX) && !(scb_s->ecd & ECD_HOSTREGMGMT)) {
571                 if (!(gpa & ~0x1fffUL)) {
572                         rc = set_validity_icpt(scb_s, 0x1310U);
573                         goto unpin;
574                 }
575                 /*
576                  * 512 bytes vector registers cannot cross page boundaries
577                  * if this block gets bigger, we have to shadow it.
578                  */
579                 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
580                 if (rc) {
581                         rc = set_validity_icpt(scb_s, 0x1310U);
582                         goto unpin;
583                 }
584                 scb_s->gvrd = hpa;
585         }
586
587         gpa = scb_o->riccbd & ~0x3fUL;
588         if (gpa && (scb_s->ecb3 & ECB3_RI)) {
589                 if (!(gpa & ~0x1fffUL)) {
590                         rc = set_validity_icpt(scb_s, 0x0043U);
591                         goto unpin;
592                 }
593                 /* 64 bytes cannot cross page boundaries */
594                 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
595                 if (rc) {
596                         rc = set_validity_icpt(scb_s, 0x0043U);
597                         goto unpin;
598                 }
599                 /* Validity 0x0044 will be checked by SIE */
600                 scb_s->riccbd = hpa;
601         }
602         if ((scb_s->ecb & ECB_GS) && !(scb_s->ecd & ECD_HOSTREGMGMT)) {
603                 unsigned long sdnxc;
604
605                 gpa = scb_o->sdnxo & ~0xfUL;
606                 sdnxc = scb_o->sdnxo & 0xfUL;
607                 if (!gpa || !(gpa & ~0x1fffUL)) {
608                         rc = set_validity_icpt(scb_s, 0x10b0U);
609                         goto unpin;
610                 }
611                 if (sdnxc < 6 || sdnxc > 12) {
612                         rc = set_validity_icpt(scb_s, 0x10b1U);
613                         goto unpin;
614                 }
615                 if (gpa & ((1 << sdnxc) - 1)) {
616                         rc = set_validity_icpt(scb_s, 0x10b2U);
617                         goto unpin;
618                 }
619                 /* Due to alignment rules (checked above) this cannot
620                  * cross page boundaries
621                  */
622                 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
623                 if (rc) {
624                         rc = set_validity_icpt(scb_s, 0x10b0U);
625                         goto unpin;
626                 }
627                 scb_s->sdnxo = hpa | sdnxc;
628         }
629         return 0;
630 unpin:
631         unpin_blocks(vcpu, vsie_page);
632         return rc;
633 }
634
635 /* unpin the scb provided by guest 2, marking it as dirty */
636 static void unpin_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page,
637                       gpa_t gpa)
638 {
639         hpa_t hpa = (hpa_t) vsie_page->scb_o;
640
641         if (hpa)
642                 unpin_guest_page(vcpu->kvm, gpa, hpa);
643         vsie_page->scb_o = NULL;
644 }
645
646 /*
647  * Pin the scb at gpa provided by guest 2 at vsie_page->scb_o.
648  *
649  * Returns: - 0 if the scb was pinned.
650  *          - > 0 if control has to be given to guest 2
651  */
652 static int pin_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page,
653                    gpa_t gpa)
654 {
655         hpa_t hpa;
656         int rc;
657
658         rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
659         if (rc) {
660                 rc = kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
661                 WARN_ON_ONCE(rc);
662                 return 1;
663         }
664         vsie_page->scb_o = (struct kvm_s390_sie_block *) hpa;
665         return 0;
666 }
667
668 /*
669  * Inject a fault into guest 2.
670  *
671  * Returns: - > 0 if control has to be given to guest 2
672  *            < 0 if an error occurred during injection.
673  */
674 static int inject_fault(struct kvm_vcpu *vcpu, __u16 code, __u64 vaddr,
675                         bool write_flag)
676 {
677         struct kvm_s390_pgm_info pgm = {
678                 .code = code,
679                 .trans_exc_code =
680                         /* 0-51: virtual address */
681                         (vaddr & 0xfffffffffffff000UL) |
682                         /* 52-53: store / fetch */
683                         (((unsigned int) !write_flag) + 1) << 10,
684                         /* 62-63: asce id (alway primary == 0) */
685                 .exc_access_id = 0, /* always primary */
686                 .op_access_id = 0, /* not MVPG */
687         };
688         int rc;
689
690         if (code == PGM_PROTECTION)
691                 pgm.trans_exc_code |= 0x4UL;
692
693         rc = kvm_s390_inject_prog_irq(vcpu, &pgm);
694         return rc ? rc : 1;
695 }
696
697 /*
698  * Handle a fault during vsie execution on a gmap shadow.
699  *
700  * Returns: - 0 if the fault was resolved
701  *          - > 0 if control has to be given to guest 2
702  *          - < 0 if an error occurred
703  */
704 static int handle_fault(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
705 {
706         int rc;
707
708         if (current->thread.gmap_int_code == PGM_PROTECTION)
709                 /* we can directly forward all protection exceptions */
710                 return inject_fault(vcpu, PGM_PROTECTION,
711                                     current->thread.gmap_addr, 1);
712
713         rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap,
714                                    current->thread.gmap_addr);
715         if (rc > 0) {
716                 rc = inject_fault(vcpu, rc,
717                                   current->thread.gmap_addr,
718                                   current->thread.gmap_write_flag);
719                 if (rc >= 0)
720                         vsie_page->fault_addr = current->thread.gmap_addr;
721         }
722         return rc;
723 }
724
725 /*
726  * Retry the previous fault that required guest 2 intervention. This avoids
727  * one superfluous SIE re-entry and direct exit.
728  *
729  * Will ignore any errors. The next SIE fault will do proper fault handling.
730  */
731 static void handle_last_fault(struct kvm_vcpu *vcpu,
732                               struct vsie_page *vsie_page)
733 {
734         if (vsie_page->fault_addr)
735                 kvm_s390_shadow_fault(vcpu, vsie_page->gmap,
736                                       vsie_page->fault_addr);
737         vsie_page->fault_addr = 0;
738 }
739
740 static inline void clear_vsie_icpt(struct vsie_page *vsie_page)
741 {
742         vsie_page->scb_s.icptcode = 0;
743 }
744
745 /* rewind the psw and clear the vsie icpt, so we can retry execution */
746 static void retry_vsie_icpt(struct vsie_page *vsie_page)
747 {
748         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
749         int ilen = insn_length(scb_s->ipa >> 8);
750
751         /* take care of EXECUTE instructions */
752         if (scb_s->icptstatus & 1) {
753                 ilen = (scb_s->icptstatus >> 4) & 0x6;
754                 if (!ilen)
755                         ilen = 4;
756         }
757         scb_s->gpsw.addr = __rewind_psw(scb_s->gpsw, ilen);
758         clear_vsie_icpt(vsie_page);
759 }
760
761 /*
762  * Try to shadow + enable the guest 2 provided facility list.
763  * Retry instruction execution if enabled for and provided by guest 2.
764  *
765  * Returns: - 0 if handled (retry or guest 2 icpt)
766  *          - > 0 if control has to be given to guest 2
767  */
768 static int handle_stfle(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
769 {
770         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
771         __u32 fac = vsie_page->scb_o->fac & 0x7ffffff8U;
772
773         if (fac && test_kvm_facility(vcpu->kvm, 7)) {
774                 retry_vsie_icpt(vsie_page);
775                 if (read_guest_real(vcpu, fac, &vsie_page->fac,
776                                     sizeof(vsie_page->fac)))
777                         return set_validity_icpt(scb_s, 0x1090U);
778                 scb_s->fac = (__u32)(__u64) &vsie_page->fac;
779         }
780         return 0;
781 }
782
783 /*
784  * Run the vsie on a shadow scb and a shadow gmap, without any further
785  * sanity checks, handling SIE faults.
786  *
787  * Returns: - 0 everything went fine
788  *          - > 0 if control has to be given to guest 2
789  *          - < 0 if an error occurred
790  */
791 static int do_vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
792 {
793         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
794         struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
795         int rc;
796
797         handle_last_fault(vcpu, vsie_page);
798
799         if (need_resched())
800                 schedule();
801         if (test_cpu_flag(CIF_MCCK_PENDING))
802                 s390_handle_mcck();
803
804         srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
805         local_irq_disable();
806         guest_enter_irqoff();
807         local_irq_enable();
808
809         rc = sie64a(scb_s, vcpu->run->s.regs.gprs);
810
811         local_irq_disable();
812         guest_exit_irqoff();
813         local_irq_enable();
814         vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
815
816         if (rc == -EINTR) {
817                 VCPU_EVENT(vcpu, 3, "%s", "machine check");
818                 kvm_s390_reinject_machine_check(vcpu, &vsie_page->mcck_info);
819                 return 0;
820         }
821
822         if (rc > 0)
823                 rc = 0; /* we could still have an icpt */
824         else if (rc == -EFAULT)
825                 return handle_fault(vcpu, vsie_page);
826
827         switch (scb_s->icptcode) {
828         case ICPT_INST:
829                 if (scb_s->ipa == 0xb2b0)
830                         rc = handle_stfle(vcpu, vsie_page);
831                 break;
832         case ICPT_STOP:
833                 /* stop not requested by g2 - must have been a kick */
834                 if (!(atomic_read(&scb_o->cpuflags) & CPUSTAT_STOP_INT))
835                         clear_vsie_icpt(vsie_page);
836                 break;
837         case ICPT_VALIDITY:
838                 if ((scb_s->ipa & 0xf000) != 0xf000)
839                         scb_s->ipa += 0x1000;
840                 break;
841         }
842         return rc;
843 }
844
845 static void release_gmap_shadow(struct vsie_page *vsie_page)
846 {
847         if (vsie_page->gmap)
848                 gmap_put(vsie_page->gmap);
849         WRITE_ONCE(vsie_page->gmap, NULL);
850         prefix_unmapped(vsie_page);
851 }
852
853 static int acquire_gmap_shadow(struct kvm_vcpu *vcpu,
854                                struct vsie_page *vsie_page)
855 {
856         unsigned long asce;
857         union ctlreg0 cr0;
858         struct gmap *gmap;
859         int edat;
860
861         asce = vcpu->arch.sie_block->gcr[1];
862         cr0.val = vcpu->arch.sie_block->gcr[0];
863         edat = cr0.edat && test_kvm_facility(vcpu->kvm, 8);
864         edat += edat && test_kvm_facility(vcpu->kvm, 78);
865
866         /*
867          * ASCE or EDAT could have changed since last icpt, or the gmap
868          * we're holding has been unshadowed. If the gmap is still valid,
869          * we can safely reuse it.
870          */
871         if (vsie_page->gmap && gmap_shadow_valid(vsie_page->gmap, asce, edat))
872                 return 0;
873
874         /* release the old shadow - if any, and mark the prefix as unmapped */
875         release_gmap_shadow(vsie_page);
876         gmap = gmap_shadow(vcpu->arch.gmap, asce, edat);
877         if (IS_ERR(gmap))
878                 return PTR_ERR(gmap);
879         gmap->private = vcpu->kvm;
880         WRITE_ONCE(vsie_page->gmap, gmap);
881         return 0;
882 }
883
884 /*
885  * Register the shadow scb at the VCPU, e.g. for kicking out of vsie.
886  */
887 static void register_shadow_scb(struct kvm_vcpu *vcpu,
888                                 struct vsie_page *vsie_page)
889 {
890         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
891
892         WRITE_ONCE(vcpu->arch.vsie_block, &vsie_page->scb_s);
893         /*
894          * External calls have to lead to a kick of the vcpu and
895          * therefore the vsie -> Simulate Wait state.
896          */
897         atomic_or(CPUSTAT_WAIT, &vcpu->arch.sie_block->cpuflags);
898         /*
899          * We have to adjust the g3 epoch by the g2 epoch. The epoch will
900          * automatically be adjusted on tod clock changes via kvm_sync_clock.
901          */
902         preempt_disable();
903         scb_s->epoch += vcpu->kvm->arch.epoch;
904
905         if (scb_s->ecd & ECD_MEF) {
906                 scb_s->epdx += vcpu->kvm->arch.epdx;
907                 if (scb_s->epoch < vcpu->kvm->arch.epoch)
908                         scb_s->epdx += 1;
909         }
910
911         preempt_enable();
912 }
913
914 /*
915  * Unregister a shadow scb from a VCPU.
916  */
917 static void unregister_shadow_scb(struct kvm_vcpu *vcpu)
918 {
919         atomic_andnot(CPUSTAT_WAIT, &vcpu->arch.sie_block->cpuflags);
920         WRITE_ONCE(vcpu->arch.vsie_block, NULL);
921 }
922
923 /*
924  * Run the vsie on a shadowed scb, managing the gmap shadow, handling
925  * prefix pages and faults.
926  *
927  * Returns: - 0 if no errors occurred
928  *          - > 0 if control has to be given to guest 2
929  *          - -ENOMEM if out of memory
930  */
931 static int vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
932 {
933         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
934         int rc = 0;
935
936         while (1) {
937                 rc = acquire_gmap_shadow(vcpu, vsie_page);
938                 if (!rc)
939                         rc = map_prefix(vcpu, vsie_page);
940                 if (!rc) {
941                         gmap_enable(vsie_page->gmap);
942                         update_intervention_requests(vsie_page);
943                         rc = do_vsie_run(vcpu, vsie_page);
944                         gmap_enable(vcpu->arch.gmap);
945                 }
946                 atomic_andnot(PROG_BLOCK_SIE, &scb_s->prog20);
947
948                 if (rc == -EAGAIN)
949                         rc = 0;
950                 if (rc || scb_s->icptcode || signal_pending(current) ||
951                     kvm_s390_vcpu_has_irq(vcpu, 0))
952                         break;
953         }
954
955         if (rc == -EFAULT) {
956                 /*
957                  * Addressing exceptions are always presentes as intercepts.
958                  * As addressing exceptions are suppressing and our guest 3 PSW
959                  * points at the responsible instruction, we have to
960                  * forward the PSW and set the ilc. If we can't read guest 3
961                  * instruction, we can use an arbitrary ilc. Let's always use
962                  * ilen = 4 for now, so we can avoid reading in guest 3 virtual
963                  * memory. (we could also fake the shadow so the hardware
964                  * handles it).
965                  */
966                 scb_s->icptcode = ICPT_PROGI;
967                 scb_s->iprcc = PGM_ADDRESSING;
968                 scb_s->pgmilc = 4;
969                 scb_s->gpsw.addr = __rewind_psw(scb_s->gpsw, 4);
970         }
971         return rc;
972 }
973
974 /*
975  * Get or create a vsie page for a scb address.
976  *
977  * Returns: - address of a vsie page (cached or new one)
978  *          - NULL if the same scb address is already used by another VCPU
979  *          - ERR_PTR(-ENOMEM) if out of memory
980  */
981 static struct vsie_page *get_vsie_page(struct kvm *kvm, unsigned long addr)
982 {
983         struct vsie_page *vsie_page;
984         struct page *page;
985         int nr_vcpus;
986
987         rcu_read_lock();
988         page = radix_tree_lookup(&kvm->arch.vsie.addr_to_page, addr >> 9);
989         rcu_read_unlock();
990         if (page) {
991                 if (page_ref_inc_return(page) == 2)
992                         return page_to_virt(page);
993                 page_ref_dec(page);
994         }
995
996         /*
997          * We want at least #online_vcpus shadows, so every VCPU can execute
998          * the VSIE in parallel.
999          */
1000         nr_vcpus = atomic_read(&kvm->online_vcpus);
1001
1002         mutex_lock(&kvm->arch.vsie.mutex);
1003         if (kvm->arch.vsie.page_count < nr_vcpus) {
1004                 page = alloc_page(GFP_KERNEL | __GFP_ZERO | GFP_DMA);
1005                 if (!page) {
1006                         mutex_unlock(&kvm->arch.vsie.mutex);
1007                         return ERR_PTR(-ENOMEM);
1008                 }
1009                 page_ref_inc(page);
1010                 kvm->arch.vsie.pages[kvm->arch.vsie.page_count] = page;
1011                 kvm->arch.vsie.page_count++;
1012         } else {
1013                 /* reuse an existing entry that belongs to nobody */
1014                 while (true) {
1015                         page = kvm->arch.vsie.pages[kvm->arch.vsie.next];
1016                         if (page_ref_inc_return(page) == 2)
1017                                 break;
1018                         page_ref_dec(page);
1019                         kvm->arch.vsie.next++;
1020                         kvm->arch.vsie.next %= nr_vcpus;
1021                 }
1022                 radix_tree_delete(&kvm->arch.vsie.addr_to_page, page->index >> 9);
1023         }
1024         page->index = addr;
1025         /* double use of the same address */
1026         if (radix_tree_insert(&kvm->arch.vsie.addr_to_page, addr >> 9, page)) {
1027                 page_ref_dec(page);
1028                 mutex_unlock(&kvm->arch.vsie.mutex);
1029                 return NULL;
1030         }
1031         mutex_unlock(&kvm->arch.vsie.mutex);
1032
1033         vsie_page = page_to_virt(page);
1034         memset(&vsie_page->scb_s, 0, sizeof(struct kvm_s390_sie_block));
1035         release_gmap_shadow(vsie_page);
1036         vsie_page->fault_addr = 0;
1037         vsie_page->scb_s.ihcpu = 0xffffU;
1038         return vsie_page;
1039 }
1040
1041 /* put a vsie page acquired via get_vsie_page */
1042 static void put_vsie_page(struct kvm *kvm, struct vsie_page *vsie_page)
1043 {
1044         struct page *page = pfn_to_page(__pa(vsie_page) >> PAGE_SHIFT);
1045
1046         page_ref_dec(page);
1047 }
1048
1049 int kvm_s390_handle_vsie(struct kvm_vcpu *vcpu)
1050 {
1051         struct vsie_page *vsie_page;
1052         unsigned long scb_addr;
1053         int rc;
1054
1055         vcpu->stat.instruction_sie++;
1056         if (!test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_SIEF2))
1057                 return -EOPNOTSUPP;
1058         if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
1059                 return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
1060
1061         BUILD_BUG_ON(sizeof(struct vsie_page) != PAGE_SIZE);
1062         scb_addr = kvm_s390_get_base_disp_s(vcpu, NULL);
1063
1064         /* 512 byte alignment */
1065         if (unlikely(scb_addr & 0x1ffUL))
1066                 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
1067
1068         if (signal_pending(current) || kvm_s390_vcpu_has_irq(vcpu, 0))
1069                 return 0;
1070
1071         vsie_page = get_vsie_page(vcpu->kvm, scb_addr);
1072         if (IS_ERR(vsie_page))
1073                 return PTR_ERR(vsie_page);
1074         else if (!vsie_page)
1075                 /* double use of sie control block - simply do nothing */
1076                 return 0;
1077
1078         rc = pin_scb(vcpu, vsie_page, scb_addr);
1079         if (rc)
1080                 goto out_put;
1081         rc = shadow_scb(vcpu, vsie_page);
1082         if (rc)
1083                 goto out_unpin_scb;
1084         rc = pin_blocks(vcpu, vsie_page);
1085         if (rc)
1086                 goto out_unshadow;
1087         register_shadow_scb(vcpu, vsie_page);
1088         rc = vsie_run(vcpu, vsie_page);
1089         unregister_shadow_scb(vcpu);
1090         unpin_blocks(vcpu, vsie_page);
1091 out_unshadow:
1092         unshadow_scb(vcpu, vsie_page);
1093 out_unpin_scb:
1094         unpin_scb(vcpu, vsie_page, scb_addr);
1095 out_put:
1096         put_vsie_page(vcpu->kvm, vsie_page);
1097
1098         return rc < 0 ? rc : 0;
1099 }
1100
1101 /* Init the vsie data structures. To be called when a vm is initialized. */
1102 void kvm_s390_vsie_init(struct kvm *kvm)
1103 {
1104         mutex_init(&kvm->arch.vsie.mutex);
1105         INIT_RADIX_TREE(&kvm->arch.vsie.addr_to_page, GFP_KERNEL);
1106 }
1107
1108 /* Destroy the vsie data structures. To be called when a vm is destroyed. */
1109 void kvm_s390_vsie_destroy(struct kvm *kvm)
1110 {
1111         struct vsie_page *vsie_page;
1112         struct page *page;
1113         int i;
1114
1115         mutex_lock(&kvm->arch.vsie.mutex);
1116         for (i = 0; i < kvm->arch.vsie.page_count; i++) {
1117                 page = kvm->arch.vsie.pages[i];
1118                 kvm->arch.vsie.pages[i] = NULL;
1119                 vsie_page = page_to_virt(page);
1120                 release_gmap_shadow(vsie_page);
1121                 /* free the radix tree entry */
1122                 radix_tree_delete(&kvm->arch.vsie.addr_to_page, page->index >> 9);
1123                 __free_page(page);
1124         }
1125         kvm->arch.vsie.page_count = 0;
1126         mutex_unlock(&kvm->arch.vsie.mutex);
1127 }
1128
1129 void kvm_s390_vsie_kick(struct kvm_vcpu *vcpu)
1130 {
1131         struct kvm_s390_sie_block *scb = READ_ONCE(vcpu->arch.vsie_block);
1132
1133         /*
1134          * Even if the VCPU lets go of the shadow sie block reference, it is
1135          * still valid in the cache. So we can safely kick it.
1136          */
1137         if (scb) {
1138                 atomic_or(PROG_BLOCK_SIE, &scb->prog20);
1139                 if (scb->prog0c & PROG_IN_SIE)
1140                         atomic_or(CPUSTAT_STOP_INT, &scb->cpuflags);
1141         }
1142 }