xref: /linux/arch/s390/kvm/vsie.c (revision 5c35a02c545a7bbe77f3a1ae337d9e29beed079b)
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 < 2 * PAGE_SIZE)
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 < 2 * PAGE_SIZE) {
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 < 2 * PAGE_SIZE) {
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 < 2 * PAGE_SIZE) {
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 < 2 * PAGE_SIZE) {
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