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Linux/arch/s390/kvm/vsie.c

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  1 // SPDX-License-Identifier: GPL-2.0
  2 /*
  3  * kvm nested virtualization support for s390x
  4  *
  5  * Copyright IBM Corp. 2016
  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         /*
 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 */
 53 static 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 */
 63 static 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 */
 69 static 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 */
 79 static 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 */
 85 static 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 */
 91 static 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  */
102 static 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 
139 /*
140  * Create a shadow copy of the crycb block and setup key wrapping, if
141  * requested for guest 3 and enabled for guest 2.
142  *
143  * We only accept format-1 (no AP in g2), but convert it into format-2
144  * There is nothing to do for format-0.
145  *
146  * Returns: - 0 if shadowed or nothing to do
147  *          - > 0 if control has to be given to guest 2
148  */
149 static int shadow_crycb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
150 {
151         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
152         struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
153         const uint32_t crycbd_o = READ_ONCE(scb_o->crycbd);
154         const u32 crycb_addr = crycbd_o & 0x7ffffff8U;
155         unsigned long *b1, *b2;
156         u8 ecb3_flags;
157 
158         scb_s->crycbd = 0;
159         if (!(crycbd_o & vcpu->arch.sie_block->crycbd & CRYCB_FORMAT1))
160                 return 0;
161         /* format-1 is supported with message-security-assist extension 3 */
162         if (!test_kvm_facility(vcpu->kvm, 76))
163                 return 0;
164         /* we may only allow it if enabled for guest 2 */
165         ecb3_flags = scb_o->ecb3 & vcpu->arch.sie_block->ecb3 &
166                      (ECB3_AES | ECB3_DEA);
167         if (!ecb3_flags)
168                 return 0;
169 
170         if ((crycb_addr & PAGE_MASK) != ((crycb_addr + 128) & PAGE_MASK))
171                 return set_validity_icpt(scb_s, 0x003CU);
172         else if (!crycb_addr)
173                 return set_validity_icpt(scb_s, 0x0039U);
174 
175         /* copy only the wrapping keys */
176         if (read_guest_real(vcpu, crycb_addr + 72, &vsie_page->crycb, 56))
177                 return set_validity_icpt(scb_s, 0x0035U);
178 
179         scb_s->ecb3 |= ecb3_flags;
180         scb_s->crycbd = ((__u32)(__u64) &vsie_page->crycb) | CRYCB_FORMAT1 |
181                         CRYCB_FORMAT2;
182 
183         /* xor both blocks in one run */
184         b1 = (unsigned long *) vsie_page->crycb.dea_wrapping_key_mask;
185         b2 = (unsigned long *)
186                             vcpu->kvm->arch.crypto.crycb->dea_wrapping_key_mask;
187         /* as 56%8 == 0, bitmap_xor won't overwrite any data */
188         bitmap_xor(b1, b1, b2, BITS_PER_BYTE * 56);
189         return 0;
190 }
191 
192 /* shadow (round up/down) the ibc to avoid validity icpt */
193 static void prepare_ibc(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
194 {
195         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
196         struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
197         /* READ_ONCE does not work on bitfields - use a temporary variable */
198         const uint32_t __new_ibc = scb_o->ibc;
199         const uint32_t new_ibc = READ_ONCE(__new_ibc) & 0x0fffU;
200         __u64 min_ibc = (sclp.ibc >> 16) & 0x0fffU;
201 
202         scb_s->ibc = 0;
203         /* ibc installed in g2 and requested for g3 */
204         if (vcpu->kvm->arch.model.ibc && new_ibc) {
205                 scb_s->ibc = new_ibc;
206                 /* takte care of the minimum ibc level of the machine */
207                 if (scb_s->ibc < min_ibc)
208                         scb_s->ibc = min_ibc;
209                 /* take care of the maximum ibc level set for the guest */
210                 if (scb_s->ibc > vcpu->kvm->arch.model.ibc)
211                         scb_s->ibc = vcpu->kvm->arch.model.ibc;
212         }
213 }
214 
215 /* unshadow the scb, copying parameters back to the real scb */
216 static void unshadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
217 {
218         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
219         struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
220 
221         /* interception */
222         scb_o->icptcode = scb_s->icptcode;
223         scb_o->icptstatus = scb_s->icptstatus;
224         scb_o->ipa = scb_s->ipa;
225         scb_o->ipb = scb_s->ipb;
226         scb_o->gbea = scb_s->gbea;
227 
228         /* timer */
229         scb_o->cputm = scb_s->cputm;
230         scb_o->ckc = scb_s->ckc;
231         scb_o->todpr = scb_s->todpr;
232 
233         /* guest state */
234         scb_o->gpsw = scb_s->gpsw;
235         scb_o->gg14 = scb_s->gg14;
236         scb_o->gg15 = scb_s->gg15;
237         memcpy(scb_o->gcr, scb_s->gcr, 128);
238         scb_o->pp = scb_s->pp;
239 
240         /* branch prediction */
241         if (test_kvm_facility(vcpu->kvm, 82)) {
242                 scb_o->fpf &= ~FPF_BPBC;
243                 scb_o->fpf |= scb_s->fpf & FPF_BPBC;
244         }
245 
246         /* interrupt intercept */
247         switch (scb_s->icptcode) {
248         case ICPT_PROGI:
249         case ICPT_INSTPROGI:
250         case ICPT_EXTINT:
251                 memcpy((void *)((u64)scb_o + 0xc0),
252                        (void *)((u64)scb_s + 0xc0), 0xf0 - 0xc0);
253                 break;
254         case ICPT_PARTEXEC:
255                 /* MVPG only */
256                 memcpy((void *)((u64)scb_o + 0xc0),
257                        (void *)((u64)scb_s + 0xc0), 0xd0 - 0xc0);
258                 break;
259         }
260 
261         if (scb_s->ihcpu != 0xffffU)
262                 scb_o->ihcpu = scb_s->ihcpu;
263 }
264 
265 /*
266  * Setup the shadow scb by copying and checking the relevant parts of the g2
267  * provided scb.
268  *
269  * Returns: - 0 if the scb has been shadowed
270  *          - > 0 if control has to be given to guest 2
271  */
272 static int shadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
273 {
274         struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
275         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
276         /* READ_ONCE does not work on bitfields - use a temporary variable */
277         const uint32_t __new_prefix = scb_o->prefix;
278         const uint32_t new_prefix = READ_ONCE(__new_prefix);
279         const bool wants_tx = READ_ONCE(scb_o->ecb) & ECB_TE;
280         bool had_tx = scb_s->ecb & ECB_TE;
281         unsigned long new_mso = 0;
282         int rc;
283 
284         /* make sure we don't have any leftovers when reusing the scb */
285         scb_s->icptcode = 0;
286         scb_s->eca = 0;
287         scb_s->ecb = 0;
288         scb_s->ecb2 = 0;
289         scb_s->ecb3 = 0;
290         scb_s->ecd = 0;
291         scb_s->fac = 0;
292         scb_s->fpf = 0;
293 
294         rc = prepare_cpuflags(vcpu, vsie_page);
295         if (rc)
296                 goto out;
297 
298         /* timer */
299         scb_s->cputm = scb_o->cputm;
300         scb_s->ckc = scb_o->ckc;
301         scb_s->todpr = scb_o->todpr;
302         scb_s->epoch = scb_o->epoch;
303 
304         /* guest state */
305         scb_s->gpsw = scb_o->gpsw;
306         scb_s->gg14 = scb_o->gg14;
307         scb_s->gg15 = scb_o->gg15;
308         memcpy(scb_s->gcr, scb_o->gcr, 128);
309         scb_s->pp = scb_o->pp;
310 
311         /* interception / execution handling */
312         scb_s->gbea = scb_o->gbea;
313         scb_s->lctl = scb_o->lctl;
314         scb_s->svcc = scb_o->svcc;
315         scb_s->ictl = scb_o->ictl;
316         /*
317          * SKEY handling functions can't deal with false setting of PTE invalid
318          * bits. Therefore we cannot provide interpretation and would later
319          * have to provide own emulation handlers.
320          */
321         if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_KSS))
322                 scb_s->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE;
323 
324         scb_s->icpua = scb_o->icpua;
325 
326         if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_SM))
327                 new_mso = READ_ONCE(scb_o->mso) & 0xfffffffffff00000UL;
328         /* if the hva of the prefix changes, we have to remap the prefix */
329         if (scb_s->mso != new_mso || scb_s->prefix != new_prefix)
330                 prefix_unmapped(vsie_page);
331          /* SIE will do mso/msl validity and exception checks for us */
332         scb_s->msl = scb_o->msl & 0xfffffffffff00000UL;
333         scb_s->mso = new_mso;
334         scb_s->prefix = new_prefix;
335 
336         /* We have to definetly flush the tlb if this scb never ran */
337         if (scb_s->ihcpu != 0xffffU)
338                 scb_s->ihcpu = scb_o->ihcpu;
339 
340         /* MVPG and Protection Exception Interpretation are always available */
341         scb_s->eca |= scb_o->eca & (ECA_MVPGI | ECA_PROTEXCI);
342         /* Host-protection-interruption introduced with ESOP */
343         if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_ESOP))
344                 scb_s->ecb |= scb_o->ecb & ECB_HOSTPROTINT;
345         /* transactional execution */
346         if (test_kvm_facility(vcpu->kvm, 73) && wants_tx) {
347                 /* remap the prefix is tx is toggled on */
348                 if (!had_tx)
349                         prefix_unmapped(vsie_page);
350                 scb_s->ecb |= ECB_TE;
351         }
352         /* branch prediction */
353         if (test_kvm_facility(vcpu->kvm, 82))
354                 scb_s->fpf |= scb_o->fpf & FPF_BPBC;
355         /* SIMD */
356         if (test_kvm_facility(vcpu->kvm, 129)) {
357                 scb_s->eca |= scb_o->eca & ECA_VX;
358                 scb_s->ecd |= scb_o->ecd & ECD_HOSTREGMGMT;
359         }
360         /* Run-time-Instrumentation */
361         if (test_kvm_facility(vcpu->kvm, 64))
362                 scb_s->ecb3 |= scb_o->ecb3 & ECB3_RI;
363         /* Instruction Execution Prevention */
364         if (test_kvm_facility(vcpu->kvm, 130))
365                 scb_s->ecb2 |= scb_o->ecb2 & ECB2_IEP;
366         /* Guarded Storage */
367         if (test_kvm_facility(vcpu->kvm, 133)) {
368                 scb_s->ecb |= scb_o->ecb & ECB_GS;
369                 scb_s->ecd |= scb_o->ecd & ECD_HOSTREGMGMT;
370         }
371         if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_SIIF))
372                 scb_s->eca |= scb_o->eca & ECA_SII;
373         if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_IB))
374                 scb_s->eca |= scb_o->eca & ECA_IB;
375         if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_CEI))
376                 scb_s->eca |= scb_o->eca & ECA_CEI;
377         /* Epoch Extension */
378         if (test_kvm_facility(vcpu->kvm, 139))
379                 scb_s->ecd |= scb_o->ecd & ECD_MEF;
380 
381         prepare_ibc(vcpu, vsie_page);
382         rc = shadow_crycb(vcpu, vsie_page);
383 out:
384         if (rc)
385                 unshadow_scb(vcpu, vsie_page);
386         return rc;
387 }
388 
389 void kvm_s390_vsie_gmap_notifier(struct gmap *gmap, unsigned long start,
390                                  unsigned long end)
391 {
392         struct kvm *kvm = gmap->private;
393         struct vsie_page *cur;
394         unsigned long prefix;
395         struct page *page;
396         int i;
397 
398         if (!gmap_is_shadow(gmap))
399                 return;
400         if (start >= 1UL << 31)
401                 /* We are only interested in prefix pages */
402                 return;
403 
404         /*
405          * Only new shadow blocks are added to the list during runtime,
406          * therefore we can safely reference them all the time.
407          */
408         for (i = 0; i < kvm->arch.vsie.page_count; i++) {
409                 page = READ_ONCE(kvm->arch.vsie.pages[i]);
410                 if (!page)
411                         continue;
412                 cur = page_to_virt(page);
413                 if (READ_ONCE(cur->gmap) != gmap)
414                         continue;
415                 prefix = cur->scb_s.prefix << GUEST_PREFIX_SHIFT;
416                 /* with mso/msl, the prefix lies at an offset */
417                 prefix += cur->scb_s.mso;
418                 if (prefix <= end && start <= prefix + 2 * PAGE_SIZE - 1)
419                         prefix_unmapped_sync(cur);
420         }
421 }
422 
423 /*
424  * Map the first prefix page and if tx is enabled also the second prefix page.
425  *
426  * The prefix will be protected, a gmap notifier will inform about unmaps.
427  * The shadow scb must not be executed until the prefix is remapped, this is
428  * guaranteed by properly handling PROG_REQUEST.
429  *
430  * Returns: - 0 on if successfully mapped or already mapped
431  *          - > 0 if control has to be given to guest 2
432  *          - -EAGAIN if the caller can retry immediately
433  *          - -ENOMEM if out of memory
434  */
435 static int map_prefix(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
436 {
437         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
438         u64 prefix = scb_s->prefix << GUEST_PREFIX_SHIFT;
439         int rc;
440 
441         if (prefix_is_mapped(vsie_page))
442                 return 0;
443 
444         /* mark it as mapped so we can catch any concurrent unmappers */
445         prefix_mapped(vsie_page);
446 
447         /* with mso/msl, the prefix lies at offset *mso* */
448         prefix += scb_s->mso;
449 
450         rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, prefix);
451         if (!rc && (scb_s->ecb & ECB_TE))
452                 rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap,
453                                            prefix + PAGE_SIZE);
454         /*
455          * We don't have to mprotect, we will be called for all unshadows.
456          * SIE will detect if protection applies and trigger a validity.
457          */
458         if (rc)
459                 prefix_unmapped(vsie_page);
460         if (rc > 0 || rc == -EFAULT)
461                 rc = set_validity_icpt(scb_s, 0x0037U);
462         return rc;
463 }
464 
465 /*
466  * Pin the guest page given by gpa and set hpa to the pinned host address.
467  * Will always be pinned writable.
468  *
469  * Returns: - 0 on success
470  *          - -EINVAL if the gpa is not valid guest storage
471  */
472 static int pin_guest_page(struct kvm *kvm, gpa_t gpa, hpa_t *hpa)
473 {
474         struct page *page;
475 
476         page = gfn_to_page(kvm, gpa_to_gfn(gpa));
477         if (is_error_page(page))
478                 return -EINVAL;
479         *hpa = (hpa_t) page_to_virt(page) + (gpa & ~PAGE_MASK);
480         return 0;
481 }
482 
483 /* Unpins a page previously pinned via pin_guest_page, marking it as dirty. */
484 static void unpin_guest_page(struct kvm *kvm, gpa_t gpa, hpa_t hpa)
485 {
486         kvm_release_pfn_dirty(hpa >> PAGE_SHIFT);
487         /* mark the page always as dirty for migration */
488         mark_page_dirty(kvm, gpa_to_gfn(gpa));
489 }
490 
491 /* unpin all blocks previously pinned by pin_blocks(), marking them dirty */
492 static void unpin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
493 {
494         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
495         hpa_t hpa;
496 
497         hpa = (u64) scb_s->scaoh << 32 | scb_s->scaol;
498         if (hpa) {
499                 unpin_guest_page(vcpu->kvm, vsie_page->sca_gpa, hpa);
500                 vsie_page->sca_gpa = 0;
501                 scb_s->scaol = 0;
502                 scb_s->scaoh = 0;
503         }
504 
505         hpa = scb_s->itdba;
506         if (hpa) {
507                 unpin_guest_page(vcpu->kvm, vsie_page->itdba_gpa, hpa);
508                 vsie_page->itdba_gpa = 0;
509                 scb_s->itdba = 0;
510         }
511 
512         hpa = scb_s->gvrd;
513         if (hpa) {
514                 unpin_guest_page(vcpu->kvm, vsie_page->gvrd_gpa, hpa);
515                 vsie_page->gvrd_gpa = 0;
516                 scb_s->gvrd = 0;
517         }
518 
519         hpa = scb_s->riccbd;
520         if (hpa) {
521                 unpin_guest_page(vcpu->kvm, vsie_page->riccbd_gpa, hpa);
522                 vsie_page->riccbd_gpa = 0;
523                 scb_s->riccbd = 0;
524         }
525 
526         hpa = scb_s->sdnxo;
527         if (hpa) {
528                 unpin_guest_page(vcpu->kvm, vsie_page->sdnx_gpa, hpa);
529                 vsie_page->sdnx_gpa = 0;
530                 scb_s->sdnxo = 0;
531         }
532 }
533 
534 /*
535  * Instead of shadowing some blocks, we can simply forward them because the
536  * addresses in the scb are 64 bit long.
537  *
538  * This works as long as the data lies in one page. If blocks ever exceed one
539  * page, we have to fall back to shadowing.
540  *
541  * As we reuse the sca, the vcpu pointers contained in it are invalid. We must
542  * therefore not enable any facilities that access these pointers (e.g. SIGPIF).
543  *
544  * Returns: - 0 if all blocks were pinned.
545  *          - > 0 if control has to be given to guest 2
546  *          - -ENOMEM if out of memory
547  */
548 static int pin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
549 {
550         struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
551         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
552         hpa_t hpa;
553         gpa_t gpa;
554         int rc = 0;
555 
556         gpa = READ_ONCE(scb_o->scaol) & ~0xfUL;
557         if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_64BSCAO))
558                 gpa |= (u64) READ_ONCE(scb_o->scaoh) << 32;
559         if (gpa) {
560                 if (!(gpa & ~0x1fffUL))
561                         rc = set_validity_icpt(scb_s, 0x0038U);
562                 else if ((gpa & ~0x1fffUL) == kvm_s390_get_prefix(vcpu))
563                         rc = set_validity_icpt(scb_s, 0x0011U);
564                 else if ((gpa & PAGE_MASK) !=
565                          ((gpa + sizeof(struct bsca_block) - 1) & PAGE_MASK))
566                         rc = set_validity_icpt(scb_s, 0x003bU);
567                 if (!rc) {
568                         rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
569                         if (rc)
570                                 rc = set_validity_icpt(scb_s, 0x0034U);
571                 }
572                 if (rc)
573                         goto unpin;
574                 vsie_page->sca_gpa = gpa;
575                 scb_s->scaoh = (u32)((u64)hpa >> 32);
576                 scb_s->scaol = (u32)(u64)hpa;
577         }
578 
579         gpa = READ_ONCE(scb_o->itdba) & ~0xffUL;
580         if (gpa && (scb_s->ecb & ECB_TE)) {
581                 if (!(gpa & ~0x1fffUL)) {
582                         rc = set_validity_icpt(scb_s, 0x0080U);
583                         goto unpin;
584                 }
585                 /* 256 bytes cannot cross page boundaries */
586                 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
587                 if (rc) {
588                         rc = set_validity_icpt(scb_s, 0x0080U);
589                         goto unpin;
590                 }
591                 vsie_page->itdba_gpa = gpa;
592                 scb_s->itdba = hpa;
593         }
594 
595         gpa = READ_ONCE(scb_o->gvrd) & ~0x1ffUL;
596         if (gpa && (scb_s->eca & ECA_VX) && !(scb_s->ecd & ECD_HOSTREGMGMT)) {
597                 if (!(gpa & ~0x1fffUL)) {
598                         rc = set_validity_icpt(scb_s, 0x1310U);
599                         goto unpin;
600                 }
601                 /*
602                  * 512 bytes vector registers cannot cross page boundaries
603                  * if this block gets bigger, we have to shadow it.
604                  */
605                 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
606                 if (rc) {
607                         rc = set_validity_icpt(scb_s, 0x1310U);
608                         goto unpin;
609                 }
610                 vsie_page->gvrd_gpa = gpa;
611                 scb_s->gvrd = hpa;
612         }
613 
614         gpa = READ_ONCE(scb_o->riccbd) & ~0x3fUL;
615         if (gpa && (scb_s->ecb3 & ECB3_RI)) {
616                 if (!(gpa & ~0x1fffUL)) {
617                         rc = set_validity_icpt(scb_s, 0x0043U);
618                         goto unpin;
619                 }
620                 /* 64 bytes cannot cross page boundaries */
621                 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
622                 if (rc) {
623                         rc = set_validity_icpt(scb_s, 0x0043U);
624                         goto unpin;
625                 }
626                 /* Validity 0x0044 will be checked by SIE */
627                 vsie_page->riccbd_gpa = gpa;
628                 scb_s->riccbd = hpa;
629         }
630         if ((scb_s->ecb & ECB_GS) && !(scb_s->ecd & ECD_HOSTREGMGMT)) {
631                 unsigned long sdnxc;
632 
633                 gpa = READ_ONCE(scb_o->sdnxo) & ~0xfUL;
634                 sdnxc = READ_ONCE(scb_o->sdnxo) & 0xfUL;
635                 if (!gpa || !(gpa & ~0x1fffUL)) {
636                         rc = set_validity_icpt(scb_s, 0x10b0U);
637                         goto unpin;
638                 }
639                 if (sdnxc < 6 || sdnxc > 12) {
640                         rc = set_validity_icpt(scb_s, 0x10b1U);
641                         goto unpin;
642                 }
643                 if (gpa & ((1 << sdnxc) - 1)) {
644                         rc = set_validity_icpt(scb_s, 0x10b2U);
645                         goto unpin;
646                 }
647                 /* Due to alignment rules (checked above) this cannot
648                  * cross page boundaries
649                  */
650                 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
651                 if (rc) {
652                         rc = set_validity_icpt(scb_s, 0x10b0U);
653                         goto unpin;
654                 }
655                 vsie_page->sdnx_gpa = gpa;
656                 scb_s->sdnxo = hpa | sdnxc;
657         }
658         return 0;
659 unpin:
660         unpin_blocks(vcpu, vsie_page);
661         return rc;
662 }
663 
664 /* unpin the scb provided by guest 2, marking it as dirty */
665 static void unpin_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page,
666                       gpa_t gpa)
667 {
668         hpa_t hpa = (hpa_t) vsie_page->scb_o;
669 
670         if (hpa)
671                 unpin_guest_page(vcpu->kvm, gpa, hpa);
672         vsie_page->scb_o = NULL;
673 }
674 
675 /*
676  * Pin the scb at gpa provided by guest 2 at vsie_page->scb_o.
677  *
678  * Returns: - 0 if the scb was pinned.
679  *          - > 0 if control has to be given to guest 2
680  */
681 static int pin_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page,
682                    gpa_t gpa)
683 {
684         hpa_t hpa;
685         int rc;
686 
687         rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
688         if (rc) {
689                 rc = kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
690                 WARN_ON_ONCE(rc);
691                 return 1;
692         }
693         vsie_page->scb_o = (struct kvm_s390_sie_block *) hpa;
694         return 0;
695 }
696 
697 /*
698  * Inject a fault into guest 2.
699  *
700  * Returns: - > 0 if control has to be given to guest 2
701  *            < 0 if an error occurred during injection.
702  */
703 static int inject_fault(struct kvm_vcpu *vcpu, __u16 code, __u64 vaddr,
704                         bool write_flag)
705 {
706         struct kvm_s390_pgm_info pgm = {
707                 .code = code,
708                 .trans_exc_code =
709                         /* 0-51: virtual address */
710                         (vaddr & 0xfffffffffffff000UL) |
711                         /* 52-53: store / fetch */
712                         (((unsigned int) !write_flag) + 1) << 10,
713                         /* 62-63: asce id (alway primary == 0) */
714                 .exc_access_id = 0, /* always primary */
715                 .op_access_id = 0, /* not MVPG */
716         };
717         int rc;
718 
719         if (code == PGM_PROTECTION)
720                 pgm.trans_exc_code |= 0x4UL;
721 
722         rc = kvm_s390_inject_prog_irq(vcpu, &pgm);
723         return rc ? rc : 1;
724 }
725 
726 /*
727  * Handle a fault during vsie execution on a gmap shadow.
728  *
729  * Returns: - 0 if the fault was resolved
730  *          - > 0 if control has to be given to guest 2
731  *          - < 0 if an error occurred
732  */
733 static int handle_fault(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
734 {
735         int rc;
736 
737         if (current->thread.gmap_int_code == PGM_PROTECTION)
738                 /* we can directly forward all protection exceptions */
739                 return inject_fault(vcpu, PGM_PROTECTION,
740                                     current->thread.gmap_addr, 1);
741 
742         rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap,
743                                    current->thread.gmap_addr);
744         if (rc > 0) {
745                 rc = inject_fault(vcpu, rc,
746                                   current->thread.gmap_addr,
747                                   current->thread.gmap_write_flag);
748                 if (rc >= 0)
749                         vsie_page->fault_addr = current->thread.gmap_addr;
750         }
751         return rc;
752 }
753 
754 /*
755  * Retry the previous fault that required guest 2 intervention. This avoids
756  * one superfluous SIE re-entry and direct exit.
757  *
758  * Will ignore any errors. The next SIE fault will do proper fault handling.
759  */
760 static void handle_last_fault(struct kvm_vcpu *vcpu,
761                               struct vsie_page *vsie_page)
762 {
763         if (vsie_page->fault_addr)
764                 kvm_s390_shadow_fault(vcpu, vsie_page->gmap,
765                                       vsie_page->fault_addr);
766         vsie_page->fault_addr = 0;
767 }
768 
769 static inline void clear_vsie_icpt(struct vsie_page *vsie_page)
770 {
771         vsie_page->scb_s.icptcode = 0;
772 }
773 
774 /* rewind the psw and clear the vsie icpt, so we can retry execution */
775 static void retry_vsie_icpt(struct vsie_page *vsie_page)
776 {
777         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
778         int ilen = insn_length(scb_s->ipa >> 8);
779 
780         /* take care of EXECUTE instructions */
781         if (scb_s->icptstatus & 1) {
782                 ilen = (scb_s->icptstatus >> 4) & 0x6;
783                 if (!ilen)
784                         ilen = 4;
785         }
786         scb_s->gpsw.addr = __rewind_psw(scb_s->gpsw, ilen);
787         clear_vsie_icpt(vsie_page);
788 }
789 
790 /*
791  * Try to shadow + enable the guest 2 provided facility list.
792  * Retry instruction execution if enabled for and provided by guest 2.
793  *
794  * Returns: - 0 if handled (retry or guest 2 icpt)
795  *          - > 0 if control has to be given to guest 2
796  */
797 static int handle_stfle(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
798 {
799         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
800         __u32 fac = READ_ONCE(vsie_page->scb_o->fac) & 0x7ffffff8U;
801 
802         if (fac && test_kvm_facility(vcpu->kvm, 7)) {
803                 retry_vsie_icpt(vsie_page);
804                 if (read_guest_real(vcpu, fac, &vsie_page->fac,
805                                     sizeof(vsie_page->fac)))
806                         return set_validity_icpt(scb_s, 0x1090U);
807                 scb_s->fac = (__u32)(__u64) &vsie_page->fac;
808         }
809         return 0;
810 }
811 
812 /*
813  * Run the vsie on a shadow scb and a shadow gmap, without any further
814  * sanity checks, handling SIE faults.
815  *
816  * Returns: - 0 everything went fine
817  *          - > 0 if control has to be given to guest 2
818  *          - < 0 if an error occurred
819  */
820 static int do_vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
821 {
822         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
823         struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
824         int guest_bp_isolation;
825         int rc;
826 
827         handle_last_fault(vcpu, vsie_page);
828 
829         if (need_resched())
830                 schedule();
831         if (test_cpu_flag(CIF_MCCK_PENDING))
832                 s390_handle_mcck();
833 
834         srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
835 
836         /* save current guest state of bp isolation override */
837         guest_bp_isolation = test_thread_flag(TIF_ISOLATE_BP_GUEST);
838 
839         /*
840          * The guest is running with BPBC, so we have to force it on for our
841          * nested guest. This is done by enabling BPBC globally, so the BPBC
842          * control in the SCB (which the nested guest can modify) is simply
843          * ignored.
844          */
845         if (test_kvm_facility(vcpu->kvm, 82) &&
846             vcpu->arch.sie_block->fpf & FPF_BPBC)
847                 set_thread_flag(TIF_ISOLATE_BP_GUEST);
848 
849         local_irq_disable();
850         guest_enter_irqoff();
851         local_irq_enable();
852 
853         rc = sie64a(scb_s, vcpu->run->s.regs.gprs);
854 
855         local_irq_disable();
856         guest_exit_irqoff();
857         local_irq_enable();
858 
859         /* restore guest state for bp isolation override */
860         if (!guest_bp_isolation)
861                 clear_thread_flag(TIF_ISOLATE_BP_GUEST);
862 
863         vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
864 
865         if (rc == -EINTR) {
866                 VCPU_EVENT(vcpu, 3, "%s", "machine check");
867                 kvm_s390_reinject_machine_check(vcpu, &vsie_page->mcck_info);
868                 return 0;
869         }
870 
871         if (rc > 0)
872                 rc = 0; /* we could still have an icpt */
873         else if (rc == -EFAULT)
874                 return handle_fault(vcpu, vsie_page);
875 
876         switch (scb_s->icptcode) {
877         case ICPT_INST:
878                 if (scb_s->ipa == 0xb2b0)
879                         rc = handle_stfle(vcpu, vsie_page);
880                 break;
881         case ICPT_STOP:
882                 /* stop not requested by g2 - must have been a kick */
883                 if (!(atomic_read(&scb_o->cpuflags) & CPUSTAT_STOP_INT))
884                         clear_vsie_icpt(vsie_page);
885                 break;
886         case ICPT_VALIDITY:
887                 if ((scb_s->ipa & 0xf000) != 0xf000)
888                         scb_s->ipa += 0x1000;
889                 break;
890         }
891         return rc;
892 }
893 
894 static void release_gmap_shadow(struct vsie_page *vsie_page)
895 {
896         if (vsie_page->gmap)
897                 gmap_put(vsie_page->gmap);
898         WRITE_ONCE(vsie_page->gmap, NULL);
899         prefix_unmapped(vsie_page);
900 }
901 
902 static int acquire_gmap_shadow(struct kvm_vcpu *vcpu,
903                                struct vsie_page *vsie_page)
904 {
905         unsigned long asce;
906         union ctlreg0 cr0;
907         struct gmap *gmap;
908         int edat;
909 
910         asce = vcpu->arch.sie_block->gcr[1];
911         cr0.val = vcpu->arch.sie_block->gcr[0];
912         edat = cr0.edat && test_kvm_facility(vcpu->kvm, 8);
913         edat += edat && test_kvm_facility(vcpu->kvm, 78);
914 
915         /*
916          * ASCE or EDAT could have changed since last icpt, or the gmap
917          * we're holding has been unshadowed. If the gmap is still valid,
918          * we can safely reuse it.
919          */
920         if (vsie_page->gmap && gmap_shadow_valid(vsie_page->gmap, asce, edat))
921                 return 0;
922 
923         /* release the old shadow - if any, and mark the prefix as unmapped */
924         release_gmap_shadow(vsie_page);
925         gmap = gmap_shadow(vcpu->arch.gmap, asce, edat);
926         if (IS_ERR(gmap))
927                 return PTR_ERR(gmap);
928         gmap->private = vcpu->kvm;
929         WRITE_ONCE(vsie_page->gmap, gmap);
930         return 0;
931 }
932 
933 /*
934  * Register the shadow scb at the VCPU, e.g. for kicking out of vsie.
935  */
936 static void register_shadow_scb(struct kvm_vcpu *vcpu,
937                                 struct vsie_page *vsie_page)
938 {
939         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
940 
941         WRITE_ONCE(vcpu->arch.vsie_block, &vsie_page->scb_s);
942         /*
943          * External calls have to lead to a kick of the vcpu and
944          * therefore the vsie -> Simulate Wait state.
945          */
946         kvm_s390_set_cpuflags(vcpu, CPUSTAT_WAIT);
947         /*
948          * We have to adjust the g3 epoch by the g2 epoch. The epoch will
949          * automatically be adjusted on tod clock changes via kvm_sync_clock.
950          */
951         preempt_disable();
952         scb_s->epoch += vcpu->kvm->arch.epoch;
953 
954         if (scb_s->ecd & ECD_MEF) {
955                 scb_s->epdx += vcpu->kvm->arch.epdx;
956                 if (scb_s->epoch < vcpu->kvm->arch.epoch)
957                         scb_s->epdx += 1;
958         }
959 
960         preempt_enable();
961 }
962 
963 /*
964  * Unregister a shadow scb from a VCPU.
965  */
966 static void unregister_shadow_scb(struct kvm_vcpu *vcpu)
967 {
968         kvm_s390_clear_cpuflags(vcpu, CPUSTAT_WAIT);
969         WRITE_ONCE(vcpu->arch.vsie_block, NULL);
970 }
971 
972 /*
973  * Run the vsie on a shadowed scb, managing the gmap shadow, handling
974  * prefix pages and faults.
975  *
976  * Returns: - 0 if no errors occurred
977  *          - > 0 if control has to be given to guest 2
978  *          - -ENOMEM if out of memory
979  */
980 static int vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
981 {
982         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
983         int rc = 0;
984 
985         while (1) {
986                 rc = acquire_gmap_shadow(vcpu, vsie_page);
987                 if (!rc)
988                         rc = map_prefix(vcpu, vsie_page);
989                 if (!rc) {
990                         gmap_enable(vsie_page->gmap);
991                         update_intervention_requests(vsie_page);
992                         rc = do_vsie_run(vcpu, vsie_page);
993                         gmap_enable(vcpu->arch.gmap);
994                 }
995                 atomic_andnot(PROG_BLOCK_SIE, &scb_s->prog20);
996 
997                 if (rc == -EAGAIN)
998                         rc = 0;
999                 if (rc || scb_s->icptcode || signal_pending(current) ||
1000                     kvm_s390_vcpu_has_irq(vcpu, 0))
1001                         break;
1002         }
1003 
1004         if (rc == -EFAULT) {
1005                 /*
1006                  * Addressing exceptions are always presentes as intercepts.
1007                  * As addressing exceptions are suppressing and our guest 3 PSW
1008                  * points at the responsible instruction, we have to
1009                  * forward the PSW and set the ilc. If we can't read guest 3
1010                  * instruction, we can use an arbitrary ilc. Let's always use
1011                  * ilen = 4 for now, so we can avoid reading in guest 3 virtual
1012                  * memory. (we could also fake the shadow so the hardware
1013                  * handles it).
1014                  */
1015                 scb_s->icptcode = ICPT_PROGI;
1016                 scb_s->iprcc = PGM_ADDRESSING;
1017                 scb_s->pgmilc = 4;
1018                 scb_s->gpsw.addr = __rewind_psw(scb_s->gpsw, 4);
1019         }
1020         return rc;
1021 }
1022 
1023 /*
1024  * Get or create a vsie page for a scb address.
1025  *
1026  * Returns: - address of a vsie page (cached or new one)
1027  *          - NULL if the same scb address is already used by another VCPU
1028  *          - ERR_PTR(-ENOMEM) if out of memory
1029  */
1030 static struct vsie_page *get_vsie_page(struct kvm *kvm, unsigned long addr)
1031 {
1032         struct vsie_page *vsie_page;
1033         struct page *page;
1034         int nr_vcpus;
1035 
1036         rcu_read_lock();
1037         page = radix_tree_lookup(&kvm->arch.vsie.addr_to_page, addr >> 9);
1038         rcu_read_unlock();
1039         if (page) {
1040                 if (page_ref_inc_return(page) == 2)
1041                         return page_to_virt(page);
1042                 page_ref_dec(page);
1043         }
1044 
1045         /*
1046          * We want at least #online_vcpus shadows, so every VCPU can execute
1047          * the VSIE in parallel.
1048          */
1049         nr_vcpus = atomic_read(&kvm->online_vcpus);
1050 
1051         mutex_lock(&kvm->arch.vsie.mutex);
1052         if (kvm->arch.vsie.page_count < nr_vcpus) {
1053                 page = alloc_page(GFP_KERNEL | __GFP_ZERO | GFP_DMA);
1054                 if (!page) {
1055                         mutex_unlock(&kvm->arch.vsie.mutex);
1056                         return ERR_PTR(-ENOMEM);
1057                 }
1058                 page_ref_inc(page);
1059                 kvm->arch.vsie.pages[kvm->arch.vsie.page_count] = page;
1060                 kvm->arch.vsie.page_count++;
1061         } else {
1062                 /* reuse an existing entry that belongs to nobody */
1063                 while (true) {
1064                         page = kvm->arch.vsie.pages[kvm->arch.vsie.next];
1065                         if (page_ref_inc_return(page) == 2)
1066                                 break;
1067                         page_ref_dec(page);
1068                         kvm->arch.vsie.next++;
1069                         kvm->arch.vsie.next %= nr_vcpus;
1070                 }
1071                 radix_tree_delete(&kvm->arch.vsie.addr_to_page, page->index >> 9);
1072         }
1073         page->index = addr;
1074         /* double use of the same address */
1075         if (radix_tree_insert(&kvm->arch.vsie.addr_to_page, addr >> 9, page)) {
1076                 page_ref_dec(page);
1077                 mutex_unlock(&kvm->arch.vsie.mutex);
1078                 return NULL;
1079         }
1080         mutex_unlock(&kvm->arch.vsie.mutex);
1081 
1082         vsie_page = page_to_virt(page);
1083         memset(&vsie_page->scb_s, 0, sizeof(struct kvm_s390_sie_block));
1084         release_gmap_shadow(vsie_page);
1085         vsie_page->fault_addr = 0;
1086         vsie_page->scb_s.ihcpu = 0xffffU;
1087         return vsie_page;
1088 }
1089 
1090 /* put a vsie page acquired via get_vsie_page */
1091 static void put_vsie_page(struct kvm *kvm, struct vsie_page *vsie_page)
1092 {
1093         struct page *page = pfn_to_page(__pa(vsie_page) >> PAGE_SHIFT);
1094 
1095         page_ref_dec(page);
1096 }
1097 
1098 int kvm_s390_handle_vsie(struct kvm_vcpu *vcpu)
1099 {
1100         struct vsie_page *vsie_page;
1101         unsigned long scb_addr;
1102         int rc;
1103 
1104         vcpu->stat.instruction_sie++;
1105         if (!test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_SIEF2))
1106                 return -EOPNOTSUPP;
1107         if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
1108                 return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
1109 
1110         BUILD_BUG_ON(sizeof(struct vsie_page) != PAGE_SIZE);
1111         scb_addr = kvm_s390_get_base_disp_s(vcpu, NULL);
1112 
1113         /* 512 byte alignment */
1114         if (unlikely(scb_addr & 0x1ffUL))
1115                 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
1116 
1117         if (signal_pending(current) || kvm_s390_vcpu_has_irq(vcpu, 0))
1118                 return 0;
1119 
1120         vsie_page = get_vsie_page(vcpu->kvm, scb_addr);
1121         if (IS_ERR(vsie_page))
1122                 return PTR_ERR(vsie_page);
1123         else if (!vsie_page)
1124                 /* double use of sie control block - simply do nothing */
1125                 return 0;
1126 
1127         rc = pin_scb(vcpu, vsie_page, scb_addr);
1128         if (rc)
1129                 goto out_put;
1130         rc = shadow_scb(vcpu, vsie_page);
1131         if (rc)
1132                 goto out_unpin_scb;
1133         rc = pin_blocks(vcpu, vsie_page);
1134         if (rc)
1135                 goto out_unshadow;
1136         register_shadow_scb(vcpu, vsie_page);
1137         rc = vsie_run(vcpu, vsie_page);
1138         unregister_shadow_scb(vcpu);
1139         unpin_blocks(vcpu, vsie_page);
1140 out_unshadow:
1141         unshadow_scb(vcpu, vsie_page);
1142 out_unpin_scb:
1143         unpin_scb(vcpu, vsie_page, scb_addr);
1144 out_put:
1145         put_vsie_page(vcpu->kvm, vsie_page);
1146 
1147         return rc < 0 ? rc : 0;
1148 }
1149 
1150 /* Init the vsie data structures. To be called when a vm is initialized. */
1151 void kvm_s390_vsie_init(struct kvm *kvm)
1152 {
1153         mutex_init(&kvm->arch.vsie.mutex);
1154         INIT_RADIX_TREE(&kvm->arch.vsie.addr_to_page, GFP_KERNEL);
1155 }
1156 
1157 /* Destroy the vsie data structures. To be called when a vm is destroyed. */
1158 void kvm_s390_vsie_destroy(struct kvm *kvm)
1159 {
1160         struct vsie_page *vsie_page;
1161         struct page *page;
1162         int i;
1163 
1164         mutex_lock(&kvm->arch.vsie.mutex);
1165         for (i = 0; i < kvm->arch.vsie.page_count; i++) {
1166                 page = kvm->arch.vsie.pages[i];
1167                 kvm->arch.vsie.pages[i] = NULL;
1168                 vsie_page = page_to_virt(page);
1169                 release_gmap_shadow(vsie_page);
1170                 /* free the radix tree entry */
1171                 radix_tree_delete(&kvm->arch.vsie.addr_to_page, page->index >> 9);
1172                 __free_page(page);
1173         }
1174         kvm->arch.vsie.page_count = 0;
1175         mutex_unlock(&kvm->arch.vsie.mutex);
1176 }
1177 
1178 void kvm_s390_vsie_kick(struct kvm_vcpu *vcpu)
1179 {
1180         struct kvm_s390_sie_block *scb = READ_ONCE(vcpu->arch.vsie_block);
1181 
1182         /*
1183          * Even if the VCPU lets go of the shadow sie block reference, it is
1184          * still valid in the cache. So we can safely kick it.
1185          */
1186         if (scb) {
1187                 atomic_or(PROG_BLOCK_SIE, &scb->prog20);
1188                 if (scb->prog0c & PROG_IN_SIE)
1189                         atomic_or(CPUSTAT_STOP_INT, &scb->cpuflags);
1190         }
1191 }
1192 

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