1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * kvm nested virtualization support for s390x
4 *
5 * Copyright IBM Corp. 2016, 2018
6 *
7 * Author(s): David Hildenbrand <dahi@linux.vnet.ibm.com>
8 */
9 #include <linux/vmalloc.h>
10 #include <linux/kvm_host.h>
11 #include <linux/bug.h>
12 #include <linux/list.h>
13 #include <linux/bitmap.h>
14 #include <linux/sched/signal.h>
15 #include <linux/io.h>
16
17 #include <asm/gmap.h>
18 #include <asm/mmu_context.h>
19 #include <asm/sclp.h>
20 #include <asm/nmi.h>
21 #include <asm/dis.h>
22 #include <asm/facility.h>
23 #include "kvm-s390.h"
24 #include "gaccess.h"
25
26 struct vsie_page {
27 struct kvm_s390_sie_block scb_s; /* 0x0000 */
28 /*
29 * the backup info for machine check. ensure it's at
30 * the same offset as that in struct sie_page!
31 */
32 struct mcck_volatile_info mcck_info; /* 0x0200 */
33 /*
34 * The pinned original scb. Be aware that other VCPUs can modify
35 * it while we read from it. Values that are used for conditions or
36 * are reused conditionally, should be accessed via READ_ONCE.
37 */
38 struct kvm_s390_sie_block *scb_o; /* 0x0218 */
39 /* the shadow gmap in use by the vsie_page */
40 struct gmap *gmap; /* 0x0220 */
41 /* address of the last reported fault to guest2 */
42 unsigned long fault_addr; /* 0x0228 */
43 /* calculated guest addresses of satellite control blocks */
44 gpa_t sca_gpa; /* 0x0230 */
45 gpa_t itdba_gpa; /* 0x0238 */
46 gpa_t gvrd_gpa; /* 0x0240 */
47 gpa_t riccbd_gpa; /* 0x0248 */
48 gpa_t sdnx_gpa; /* 0x0250 */
49 __u8 reserved[0x0700 - 0x0258]; /* 0x0258 */
50 struct kvm_s390_crypto_cb crycb; /* 0x0700 */
51 __u8 fac[S390_ARCH_FAC_LIST_SIZE_BYTE]; /* 0x0800 */
52 };
53
54 /* trigger a validity icpt for the given scb */
set_validity_icpt(struct kvm_s390_sie_block * scb,__u16 reason_code)55 static int set_validity_icpt(struct kvm_s390_sie_block *scb,
56 __u16 reason_code)
57 {
58 scb->ipa = 0x1000;
59 scb->ipb = ((__u32) reason_code) << 16;
60 scb->icptcode = ICPT_VALIDITY;
61 return 1;
62 }
63
64 /* mark the prefix as unmapped, this will block the VSIE */
prefix_unmapped(struct vsie_page * vsie_page)65 static void prefix_unmapped(struct vsie_page *vsie_page)
66 {
67 atomic_or(PROG_REQUEST, &vsie_page->scb_s.prog20);
68 }
69
70 /* mark the prefix as unmapped and wait until the VSIE has been left */
prefix_unmapped_sync(struct vsie_page * vsie_page)71 static void prefix_unmapped_sync(struct vsie_page *vsie_page)
72 {
73 prefix_unmapped(vsie_page);
74 if (vsie_page->scb_s.prog0c & PROG_IN_SIE)
75 atomic_or(CPUSTAT_STOP_INT, &vsie_page->scb_s.cpuflags);
76 while (vsie_page->scb_s.prog0c & PROG_IN_SIE)
77 cpu_relax();
78 }
79
80 /* mark the prefix as mapped, this will allow the VSIE to run */
prefix_mapped(struct vsie_page * vsie_page)81 static void prefix_mapped(struct vsie_page *vsie_page)
82 {
83 atomic_andnot(PROG_REQUEST, &vsie_page->scb_s.prog20);
84 }
85
86 /* test if the prefix is mapped into the gmap shadow */
prefix_is_mapped(struct vsie_page * vsie_page)87 static int prefix_is_mapped(struct vsie_page *vsie_page)
88 {
89 return !(atomic_read(&vsie_page->scb_s.prog20) & PROG_REQUEST);
90 }
91
92 /* copy the updated intervention request bits into the shadow scb */
update_intervention_requests(struct vsie_page * vsie_page)93 static void update_intervention_requests(struct vsie_page *vsie_page)
94 {
95 const int bits = CPUSTAT_STOP_INT | CPUSTAT_IO_INT | CPUSTAT_EXT_INT;
96 int cpuflags;
97
98 cpuflags = atomic_read(&vsie_page->scb_o->cpuflags);
99 atomic_andnot(bits, &vsie_page->scb_s.cpuflags);
100 atomic_or(cpuflags & bits, &vsie_page->scb_s.cpuflags);
101 }
102
103 /* shadow (filter and validate) the cpuflags */
prepare_cpuflags(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page)104 static int prepare_cpuflags(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
105 {
106 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
107 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
108 int newflags, cpuflags = atomic_read(&scb_o->cpuflags);
109
110 /* we don't allow ESA/390 guests */
111 if (!(cpuflags & CPUSTAT_ZARCH))
112 return set_validity_icpt(scb_s, 0x0001U);
113
114 if (cpuflags & (CPUSTAT_RRF | CPUSTAT_MCDS))
115 return set_validity_icpt(scb_s, 0x0001U);
116 else if (cpuflags & (CPUSTAT_SLSV | CPUSTAT_SLSR))
117 return set_validity_icpt(scb_s, 0x0007U);
118
119 /* intervention requests will be set later */
120 newflags = CPUSTAT_ZARCH;
121 if (cpuflags & CPUSTAT_GED && test_kvm_facility(vcpu->kvm, 8))
122 newflags |= CPUSTAT_GED;
123 if (cpuflags & CPUSTAT_GED2 && test_kvm_facility(vcpu->kvm, 78)) {
124 if (cpuflags & CPUSTAT_GED)
125 return set_validity_icpt(scb_s, 0x0001U);
126 newflags |= CPUSTAT_GED2;
127 }
128 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_GPERE))
129 newflags |= cpuflags & CPUSTAT_P;
130 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_GSLS))
131 newflags |= cpuflags & CPUSTAT_SM;
132 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_IBS))
133 newflags |= cpuflags & CPUSTAT_IBS;
134 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_KSS))
135 newflags |= cpuflags & CPUSTAT_KSS;
136
137 atomic_set(&scb_s->cpuflags, newflags);
138 return 0;
139 }
140 /* Copy to APCB FORMAT1 from APCB FORMAT0 */
setup_apcb10(struct kvm_vcpu * vcpu,struct kvm_s390_apcb1 * apcb_s,unsigned long crycb_gpa,struct kvm_s390_apcb1 * apcb_h)141 static int setup_apcb10(struct kvm_vcpu *vcpu, struct kvm_s390_apcb1 *apcb_s,
142 unsigned long crycb_gpa, struct kvm_s390_apcb1 *apcb_h)
143 {
144 struct kvm_s390_apcb0 tmp;
145 unsigned long apcb_gpa;
146
147 apcb_gpa = crycb_gpa + offsetof(struct kvm_s390_crypto_cb, apcb0);
148
149 if (read_guest_real(vcpu, apcb_gpa, &tmp,
150 sizeof(struct kvm_s390_apcb0)))
151 return -EFAULT;
152
153 apcb_s->apm[0] = apcb_h->apm[0] & tmp.apm[0];
154 apcb_s->aqm[0] = apcb_h->aqm[0] & tmp.aqm[0] & 0xffff000000000000UL;
155 apcb_s->adm[0] = apcb_h->adm[0] & tmp.adm[0] & 0xffff000000000000UL;
156
157 return 0;
158
159 }
160
161 /**
162 * setup_apcb00 - Copy to APCB FORMAT0 from APCB FORMAT0
163 * @vcpu: pointer to the virtual CPU
164 * @apcb_s: pointer to start of apcb in the shadow crycb
165 * @crycb_gpa: guest physical address to start of original guest crycb
166 * @apcb_h: pointer to start of apcb in the guest1
167 *
168 * Returns 0 and -EFAULT on error reading guest apcb
169 */
setup_apcb00(struct kvm_vcpu * vcpu,unsigned long * apcb_s,unsigned long crycb_gpa,unsigned long * apcb_h)170 static int setup_apcb00(struct kvm_vcpu *vcpu, unsigned long *apcb_s,
171 unsigned long crycb_gpa, unsigned long *apcb_h)
172 {
173 unsigned long apcb_gpa;
174
175 apcb_gpa = crycb_gpa + offsetof(struct kvm_s390_crypto_cb, apcb0);
176
177 if (read_guest_real(vcpu, apcb_gpa, apcb_s,
178 sizeof(struct kvm_s390_apcb0)))
179 return -EFAULT;
180
181 bitmap_and(apcb_s, apcb_s, apcb_h,
182 BITS_PER_BYTE * sizeof(struct kvm_s390_apcb0));
183
184 return 0;
185 }
186
187 /**
188 * setup_apcb11 - Copy the FORMAT1 APCB from the guest to the shadow CRYCB
189 * @vcpu: pointer to the virtual CPU
190 * @apcb_s: pointer to start of apcb in the shadow crycb
191 * @crycb_gpa: guest physical address to start of original guest crycb
192 * @apcb_h: pointer to start of apcb in the host
193 *
194 * Returns 0 and -EFAULT on error reading guest apcb
195 */
setup_apcb11(struct kvm_vcpu * vcpu,unsigned long * apcb_s,unsigned long crycb_gpa,unsigned long * apcb_h)196 static int setup_apcb11(struct kvm_vcpu *vcpu, unsigned long *apcb_s,
197 unsigned long crycb_gpa,
198 unsigned long *apcb_h)
199 {
200 unsigned long apcb_gpa;
201
202 apcb_gpa = crycb_gpa + offsetof(struct kvm_s390_crypto_cb, apcb1);
203
204 if (read_guest_real(vcpu, apcb_gpa, apcb_s,
205 sizeof(struct kvm_s390_apcb1)))
206 return -EFAULT;
207
208 bitmap_and(apcb_s, apcb_s, apcb_h,
209 BITS_PER_BYTE * sizeof(struct kvm_s390_apcb1));
210
211 return 0;
212 }
213
214 /**
215 * setup_apcb - Create a shadow copy of the apcb.
216 * @vcpu: pointer to the virtual CPU
217 * @crycb_s: pointer to shadow crycb
218 * @crycb_gpa: guest physical address of original guest crycb
219 * @crycb_h: pointer to the host crycb
220 * @fmt_o: format of the original guest crycb.
221 * @fmt_h: format of the host crycb.
222 *
223 * Checks the compatibility between the guest and host crycb and calls the
224 * appropriate copy function.
225 *
226 * Return 0 or an error number if the guest and host crycb are incompatible.
227 */
setup_apcb(struct kvm_vcpu * vcpu,struct kvm_s390_crypto_cb * crycb_s,const u32 crycb_gpa,struct kvm_s390_crypto_cb * crycb_h,int fmt_o,int fmt_h)228 static int setup_apcb(struct kvm_vcpu *vcpu, struct kvm_s390_crypto_cb *crycb_s,
229 const u32 crycb_gpa,
230 struct kvm_s390_crypto_cb *crycb_h,
231 int fmt_o, int fmt_h)
232 {
233 switch (fmt_o) {
234 case CRYCB_FORMAT2:
235 if ((crycb_gpa & PAGE_MASK) != ((crycb_gpa + 256) & PAGE_MASK))
236 return -EACCES;
237 if (fmt_h != CRYCB_FORMAT2)
238 return -EINVAL;
239 return setup_apcb11(vcpu, (unsigned long *)&crycb_s->apcb1,
240 crycb_gpa,
241 (unsigned long *)&crycb_h->apcb1);
242 case CRYCB_FORMAT1:
243 switch (fmt_h) {
244 case CRYCB_FORMAT2:
245 return setup_apcb10(vcpu, &crycb_s->apcb1,
246 crycb_gpa,
247 &crycb_h->apcb1);
248 case CRYCB_FORMAT1:
249 return setup_apcb00(vcpu,
250 (unsigned long *) &crycb_s->apcb0,
251 crycb_gpa,
252 (unsigned long *) &crycb_h->apcb0);
253 }
254 break;
255 case CRYCB_FORMAT0:
256 if ((crycb_gpa & PAGE_MASK) != ((crycb_gpa + 32) & PAGE_MASK))
257 return -EACCES;
258
259 switch (fmt_h) {
260 case CRYCB_FORMAT2:
261 return setup_apcb10(vcpu, &crycb_s->apcb1,
262 crycb_gpa,
263 &crycb_h->apcb1);
264 case CRYCB_FORMAT1:
265 case CRYCB_FORMAT0:
266 return setup_apcb00(vcpu,
267 (unsigned long *) &crycb_s->apcb0,
268 crycb_gpa,
269 (unsigned long *) &crycb_h->apcb0);
270 }
271 }
272 return -EINVAL;
273 }
274
275 /**
276 * shadow_crycb - Create a shadow copy of the crycb block
277 * @vcpu: a pointer to the virtual CPU
278 * @vsie_page: a pointer to internal date used for the vSIE
279 *
280 * Create a shadow copy of the crycb block and setup key wrapping, if
281 * requested for guest 3 and enabled for guest 2.
282 *
283 * We accept format-1 or format-2, but we convert format-1 into format-2
284 * in the shadow CRYCB.
285 * Using format-2 enables the firmware to choose the right format when
286 * scheduling the SIE.
287 * There is nothing to do for format-0.
288 *
289 * This function centralize the issuing of set_validity_icpt() for all
290 * the subfunctions working on the crycb.
291 *
292 * Returns: - 0 if shadowed or nothing to do
293 * - > 0 if control has to be given to guest 2
294 */
shadow_crycb(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page)295 static int shadow_crycb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
296 {
297 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
298 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
299 const uint32_t crycbd_o = READ_ONCE(scb_o->crycbd);
300 const u32 crycb_addr = crycbd_o & 0x7ffffff8U;
301 unsigned long *b1, *b2;
302 u8 ecb3_flags;
303 u32 ecd_flags;
304 int apie_h;
305 int apie_s;
306 int key_msk = test_kvm_facility(vcpu->kvm, 76);
307 int fmt_o = crycbd_o & CRYCB_FORMAT_MASK;
308 int fmt_h = vcpu->arch.sie_block->crycbd & CRYCB_FORMAT_MASK;
309 int ret = 0;
310
311 scb_s->crycbd = 0;
312
313 apie_h = vcpu->arch.sie_block->eca & ECA_APIE;
314 apie_s = apie_h & scb_o->eca;
315 if (!apie_s && (!key_msk || (fmt_o == CRYCB_FORMAT0)))
316 return 0;
317
318 if (!crycb_addr)
319 return set_validity_icpt(scb_s, 0x0039U);
320
321 if (fmt_o == CRYCB_FORMAT1)
322 if ((crycb_addr & PAGE_MASK) !=
323 ((crycb_addr + 128) & PAGE_MASK))
324 return set_validity_icpt(scb_s, 0x003CU);
325
326 if (apie_s) {
327 ret = setup_apcb(vcpu, &vsie_page->crycb, crycb_addr,
328 vcpu->kvm->arch.crypto.crycb,
329 fmt_o, fmt_h);
330 if (ret)
331 goto end;
332 scb_s->eca |= scb_o->eca & ECA_APIE;
333 }
334
335 /* we may only allow it if enabled for guest 2 */
336 ecb3_flags = scb_o->ecb3 & vcpu->arch.sie_block->ecb3 &
337 (ECB3_AES | ECB3_DEA);
338 ecd_flags = scb_o->ecd & vcpu->arch.sie_block->ecd & ECD_ECC;
339 if (!ecb3_flags && !ecd_flags)
340 goto end;
341
342 /* copy only the wrapping keys */
343 if (read_guest_real(vcpu, crycb_addr + 72,
344 vsie_page->crycb.dea_wrapping_key_mask, 56))
345 return set_validity_icpt(scb_s, 0x0035U);
346
347 scb_s->ecb3 |= ecb3_flags;
348 scb_s->ecd |= ecd_flags;
349
350 /* xor both blocks in one run */
351 b1 = (unsigned long *) vsie_page->crycb.dea_wrapping_key_mask;
352 b2 = (unsigned long *)
353 vcpu->kvm->arch.crypto.crycb->dea_wrapping_key_mask;
354 /* as 56%8 == 0, bitmap_xor won't overwrite any data */
355 bitmap_xor(b1, b1, b2, BITS_PER_BYTE * 56);
356 end:
357 switch (ret) {
358 case -EINVAL:
359 return set_validity_icpt(scb_s, 0x0022U);
360 case -EFAULT:
361 return set_validity_icpt(scb_s, 0x0035U);
362 case -EACCES:
363 return set_validity_icpt(scb_s, 0x003CU);
364 }
365 scb_s->crycbd = (u32)virt_to_phys(&vsie_page->crycb) | CRYCB_FORMAT2;
366 return 0;
367 }
368
369 /* shadow (round up/down) the ibc to avoid validity icpt */
prepare_ibc(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page)370 static void prepare_ibc(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
371 {
372 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
373 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
374 /* READ_ONCE does not work on bitfields - use a temporary variable */
375 const uint32_t __new_ibc = scb_o->ibc;
376 const uint32_t new_ibc = READ_ONCE(__new_ibc) & 0x0fffU;
377 __u64 min_ibc = (sclp.ibc >> 16) & 0x0fffU;
378
379 scb_s->ibc = 0;
380 /* ibc installed in g2 and requested for g3 */
381 if (vcpu->kvm->arch.model.ibc && new_ibc) {
382 scb_s->ibc = new_ibc;
383 /* takte care of the minimum ibc level of the machine */
384 if (scb_s->ibc < min_ibc)
385 scb_s->ibc = min_ibc;
386 /* take care of the maximum ibc level set for the guest */
387 if (scb_s->ibc > vcpu->kvm->arch.model.ibc)
388 scb_s->ibc = vcpu->kvm->arch.model.ibc;
389 }
390 }
391
392 /* unshadow the scb, copying parameters back to the real scb */
unshadow_scb(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page)393 static void unshadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
394 {
395 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
396 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
397
398 /* interception */
399 scb_o->icptcode = scb_s->icptcode;
400 scb_o->icptstatus = scb_s->icptstatus;
401 scb_o->ipa = scb_s->ipa;
402 scb_o->ipb = scb_s->ipb;
403 scb_o->gbea = scb_s->gbea;
404
405 /* timer */
406 scb_o->cputm = scb_s->cputm;
407 scb_o->ckc = scb_s->ckc;
408 scb_o->todpr = scb_s->todpr;
409
410 /* guest state */
411 scb_o->gpsw = scb_s->gpsw;
412 scb_o->gg14 = scb_s->gg14;
413 scb_o->gg15 = scb_s->gg15;
414 memcpy(scb_o->gcr, scb_s->gcr, 128);
415 scb_o->pp = scb_s->pp;
416
417 /* branch prediction */
418 if (test_kvm_facility(vcpu->kvm, 82)) {
419 scb_o->fpf &= ~FPF_BPBC;
420 scb_o->fpf |= scb_s->fpf & FPF_BPBC;
421 }
422
423 /* interrupt intercept */
424 switch (scb_s->icptcode) {
425 case ICPT_PROGI:
426 case ICPT_INSTPROGI:
427 case ICPT_EXTINT:
428 memcpy((void *)((u64)scb_o + 0xc0),
429 (void *)((u64)scb_s + 0xc0), 0xf0 - 0xc0);
430 break;
431 }
432
433 if (scb_s->ihcpu != 0xffffU)
434 scb_o->ihcpu = scb_s->ihcpu;
435 }
436
437 /*
438 * Setup the shadow scb by copying and checking the relevant parts of the g2
439 * provided scb.
440 *
441 * Returns: - 0 if the scb has been shadowed
442 * - > 0 if control has to be given to guest 2
443 */
shadow_scb(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page)444 static int shadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
445 {
446 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
447 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
448 /* READ_ONCE does not work on bitfields - use a temporary variable */
449 const uint32_t __new_prefix = scb_o->prefix;
450 const uint32_t new_prefix = READ_ONCE(__new_prefix);
451 const bool wants_tx = READ_ONCE(scb_o->ecb) & ECB_TE;
452 bool had_tx = scb_s->ecb & ECB_TE;
453 unsigned long new_mso = 0;
454 int rc;
455
456 /* make sure we don't have any leftovers when reusing the scb */
457 scb_s->icptcode = 0;
458 scb_s->eca = 0;
459 scb_s->ecb = 0;
460 scb_s->ecb2 = 0;
461 scb_s->ecb3 = 0;
462 scb_s->ecd = 0;
463 scb_s->fac = 0;
464 scb_s->fpf = 0;
465
466 rc = prepare_cpuflags(vcpu, vsie_page);
467 if (rc)
468 goto out;
469
470 /* timer */
471 scb_s->cputm = scb_o->cputm;
472 scb_s->ckc = scb_o->ckc;
473 scb_s->todpr = scb_o->todpr;
474 scb_s->epoch = scb_o->epoch;
475
476 /* guest state */
477 scb_s->gpsw = scb_o->gpsw;
478 scb_s->gg14 = scb_o->gg14;
479 scb_s->gg15 = scb_o->gg15;
480 memcpy(scb_s->gcr, scb_o->gcr, 128);
481 scb_s->pp = scb_o->pp;
482
483 /* interception / execution handling */
484 scb_s->gbea = scb_o->gbea;
485 scb_s->lctl = scb_o->lctl;
486 scb_s->svcc = scb_o->svcc;
487 scb_s->ictl = scb_o->ictl;
488 /*
489 * SKEY handling functions can't deal with false setting of PTE invalid
490 * bits. Therefore we cannot provide interpretation and would later
491 * have to provide own emulation handlers.
492 */
493 if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_KSS))
494 scb_s->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE;
495
496 scb_s->icpua = scb_o->icpua;
497
498 if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_SM))
499 new_mso = READ_ONCE(scb_o->mso) & 0xfffffffffff00000UL;
500 /* if the hva of the prefix changes, we have to remap the prefix */
501 if (scb_s->mso != new_mso || scb_s->prefix != new_prefix)
502 prefix_unmapped(vsie_page);
503 /* SIE will do mso/msl validity and exception checks for us */
504 scb_s->msl = scb_o->msl & 0xfffffffffff00000UL;
505 scb_s->mso = new_mso;
506 scb_s->prefix = new_prefix;
507
508 /* We have to definitely flush the tlb if this scb never ran */
509 if (scb_s->ihcpu != 0xffffU)
510 scb_s->ihcpu = scb_o->ihcpu;
511
512 /* MVPG and Protection Exception Interpretation are always available */
513 scb_s->eca |= scb_o->eca & (ECA_MVPGI | ECA_PROTEXCI);
514 /* Host-protection-interruption introduced with ESOP */
515 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_ESOP))
516 scb_s->ecb |= scb_o->ecb & ECB_HOSTPROTINT;
517 /*
518 * CPU Topology
519 * This facility only uses the utility field of the SCA and none of
520 * the cpu entries that are problematic with the other interpretation
521 * facilities so we can pass it through
522 */
523 if (test_kvm_facility(vcpu->kvm, 11))
524 scb_s->ecb |= scb_o->ecb & ECB_PTF;
525 /* transactional execution */
526 if (test_kvm_facility(vcpu->kvm, 73) && wants_tx) {
527 /* remap the prefix is tx is toggled on */
528 if (!had_tx)
529 prefix_unmapped(vsie_page);
530 scb_s->ecb |= ECB_TE;
531 }
532 /* specification exception interpretation */
533 scb_s->ecb |= scb_o->ecb & ECB_SPECI;
534 /* branch prediction */
535 if (test_kvm_facility(vcpu->kvm, 82))
536 scb_s->fpf |= scb_o->fpf & FPF_BPBC;
537 /* SIMD */
538 if (test_kvm_facility(vcpu->kvm, 129)) {
539 scb_s->eca |= scb_o->eca & ECA_VX;
540 scb_s->ecd |= scb_o->ecd & ECD_HOSTREGMGMT;
541 }
542 /* Run-time-Instrumentation */
543 if (test_kvm_facility(vcpu->kvm, 64))
544 scb_s->ecb3 |= scb_o->ecb3 & ECB3_RI;
545 /* Instruction Execution Prevention */
546 if (test_kvm_facility(vcpu->kvm, 130))
547 scb_s->ecb2 |= scb_o->ecb2 & ECB2_IEP;
548 /* Guarded Storage */
549 if (test_kvm_facility(vcpu->kvm, 133)) {
550 scb_s->ecb |= scb_o->ecb & ECB_GS;
551 scb_s->ecd |= scb_o->ecd & ECD_HOSTREGMGMT;
552 }
553 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_SIIF))
554 scb_s->eca |= scb_o->eca & ECA_SII;
555 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_IB))
556 scb_s->eca |= scb_o->eca & ECA_IB;
557 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_CEI))
558 scb_s->eca |= scb_o->eca & ECA_CEI;
559 /* Epoch Extension */
560 if (test_kvm_facility(vcpu->kvm, 139)) {
561 scb_s->ecd |= scb_o->ecd & ECD_MEF;
562 scb_s->epdx = scb_o->epdx;
563 }
564
565 /* etoken */
566 if (test_kvm_facility(vcpu->kvm, 156))
567 scb_s->ecd |= scb_o->ecd & ECD_ETOKENF;
568
569 scb_s->hpid = HPID_VSIE;
570 scb_s->cpnc = scb_o->cpnc;
571
572 prepare_ibc(vcpu, vsie_page);
573 rc = shadow_crycb(vcpu, vsie_page);
574 out:
575 if (rc)
576 unshadow_scb(vcpu, vsie_page);
577 return rc;
578 }
579
kvm_s390_vsie_gmap_notifier(struct gmap * gmap,unsigned long start,unsigned long end)580 void kvm_s390_vsie_gmap_notifier(struct gmap *gmap, unsigned long start,
581 unsigned long end)
582 {
583 struct kvm *kvm = gmap->private;
584 struct vsie_page *cur;
585 unsigned long prefix;
586 struct page *page;
587 int i;
588
589 if (!gmap_is_shadow(gmap))
590 return;
591 /*
592 * Only new shadow blocks are added to the list during runtime,
593 * therefore we can safely reference them all the time.
594 */
595 for (i = 0; i < kvm->arch.vsie.page_count; i++) {
596 page = READ_ONCE(kvm->arch.vsie.pages[i]);
597 if (!page)
598 continue;
599 cur = page_to_virt(page);
600 if (READ_ONCE(cur->gmap) != gmap)
601 continue;
602 prefix = cur->scb_s.prefix << GUEST_PREFIX_SHIFT;
603 /* with mso/msl, the prefix lies at an offset */
604 prefix += cur->scb_s.mso;
605 if (prefix <= end && start <= prefix + 2 * PAGE_SIZE - 1)
606 prefix_unmapped_sync(cur);
607 }
608 }
609
610 /*
611 * Map the first prefix page and if tx is enabled also the second prefix page.
612 *
613 * The prefix will be protected, a gmap notifier will inform about unmaps.
614 * The shadow scb must not be executed until the prefix is remapped, this is
615 * guaranteed by properly handling PROG_REQUEST.
616 *
617 * Returns: - 0 on if successfully mapped or already mapped
618 * - > 0 if control has to be given to guest 2
619 * - -EAGAIN if the caller can retry immediately
620 * - -ENOMEM if out of memory
621 */
map_prefix(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page)622 static int map_prefix(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
623 {
624 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
625 u64 prefix = scb_s->prefix << GUEST_PREFIX_SHIFT;
626 int rc;
627
628 if (prefix_is_mapped(vsie_page))
629 return 0;
630
631 /* mark it as mapped so we can catch any concurrent unmappers */
632 prefix_mapped(vsie_page);
633
634 /* with mso/msl, the prefix lies at offset *mso* */
635 prefix += scb_s->mso;
636
637 rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, prefix, NULL);
638 if (!rc && (scb_s->ecb & ECB_TE))
639 rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap,
640 prefix + PAGE_SIZE, NULL);
641 /*
642 * We don't have to mprotect, we will be called for all unshadows.
643 * SIE will detect if protection applies and trigger a validity.
644 */
645 if (rc)
646 prefix_unmapped(vsie_page);
647 if (rc > 0 || rc == -EFAULT)
648 rc = set_validity_icpt(scb_s, 0x0037U);
649 return rc;
650 }
651
652 /*
653 * Pin the guest page given by gpa and set hpa to the pinned host address.
654 * Will always be pinned writable.
655 *
656 * Returns: - 0 on success
657 * - -EINVAL if the gpa is not valid guest storage
658 */
pin_guest_page(struct kvm * kvm,gpa_t gpa,hpa_t * hpa)659 static int pin_guest_page(struct kvm *kvm, gpa_t gpa, hpa_t *hpa)
660 {
661 struct page *page;
662
663 page = gfn_to_page(kvm, gpa_to_gfn(gpa));
664 if (is_error_page(page))
665 return -EINVAL;
666 *hpa = (hpa_t)page_to_phys(page) + (gpa & ~PAGE_MASK);
667 return 0;
668 }
669
670 /* Unpins a page previously pinned via pin_guest_page, marking it as dirty. */
unpin_guest_page(struct kvm * kvm,gpa_t gpa,hpa_t hpa)671 static void unpin_guest_page(struct kvm *kvm, gpa_t gpa, hpa_t hpa)
672 {
673 kvm_release_pfn_dirty(hpa >> PAGE_SHIFT);
674 /* mark the page always as dirty for migration */
675 mark_page_dirty(kvm, gpa_to_gfn(gpa));
676 }
677
678 /* unpin all blocks previously pinned by pin_blocks(), marking them dirty */
unpin_blocks(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page)679 static void unpin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
680 {
681 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
682 hpa_t hpa;
683
684 hpa = (u64) scb_s->scaoh << 32 | scb_s->scaol;
685 if (hpa) {
686 unpin_guest_page(vcpu->kvm, vsie_page->sca_gpa, hpa);
687 vsie_page->sca_gpa = 0;
688 scb_s->scaol = 0;
689 scb_s->scaoh = 0;
690 }
691
692 hpa = scb_s->itdba;
693 if (hpa) {
694 unpin_guest_page(vcpu->kvm, vsie_page->itdba_gpa, hpa);
695 vsie_page->itdba_gpa = 0;
696 scb_s->itdba = 0;
697 }
698
699 hpa = scb_s->gvrd;
700 if (hpa) {
701 unpin_guest_page(vcpu->kvm, vsie_page->gvrd_gpa, hpa);
702 vsie_page->gvrd_gpa = 0;
703 scb_s->gvrd = 0;
704 }
705
706 hpa = scb_s->riccbd;
707 if (hpa) {
708 unpin_guest_page(vcpu->kvm, vsie_page->riccbd_gpa, hpa);
709 vsie_page->riccbd_gpa = 0;
710 scb_s->riccbd = 0;
711 }
712
713 hpa = scb_s->sdnxo;
714 if (hpa) {
715 unpin_guest_page(vcpu->kvm, vsie_page->sdnx_gpa, hpa);
716 vsie_page->sdnx_gpa = 0;
717 scb_s->sdnxo = 0;
718 }
719 }
720
721 /*
722 * Instead of shadowing some blocks, we can simply forward them because the
723 * addresses in the scb are 64 bit long.
724 *
725 * This works as long as the data lies in one page. If blocks ever exceed one
726 * page, we have to fall back to shadowing.
727 *
728 * As we reuse the sca, the vcpu pointers contained in it are invalid. We must
729 * therefore not enable any facilities that access these pointers (e.g. SIGPIF).
730 *
731 * Returns: - 0 if all blocks were pinned.
732 * - > 0 if control has to be given to guest 2
733 * - -ENOMEM if out of memory
734 */
pin_blocks(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page)735 static int pin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
736 {
737 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
738 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
739 hpa_t hpa;
740 gpa_t gpa;
741 int rc = 0;
742
743 gpa = READ_ONCE(scb_o->scaol) & ~0xfUL;
744 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_64BSCAO))
745 gpa |= (u64) READ_ONCE(scb_o->scaoh) << 32;
746 if (gpa) {
747 if (gpa < 2 * PAGE_SIZE)
748 rc = set_validity_icpt(scb_s, 0x0038U);
749 else if ((gpa & ~0x1fffUL) == kvm_s390_get_prefix(vcpu))
750 rc = set_validity_icpt(scb_s, 0x0011U);
751 else if ((gpa & PAGE_MASK) !=
752 ((gpa + sizeof(struct bsca_block) - 1) & PAGE_MASK))
753 rc = set_validity_icpt(scb_s, 0x003bU);
754 if (!rc) {
755 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
756 if (rc)
757 rc = set_validity_icpt(scb_s, 0x0034U);
758 }
759 if (rc)
760 goto unpin;
761 vsie_page->sca_gpa = gpa;
762 scb_s->scaoh = (u32)((u64)hpa >> 32);
763 scb_s->scaol = (u32)(u64)hpa;
764 }
765
766 gpa = READ_ONCE(scb_o->itdba) & ~0xffUL;
767 if (gpa && (scb_s->ecb & ECB_TE)) {
768 if (gpa < 2 * PAGE_SIZE) {
769 rc = set_validity_icpt(scb_s, 0x0080U);
770 goto unpin;
771 }
772 /* 256 bytes cannot cross page boundaries */
773 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
774 if (rc) {
775 rc = set_validity_icpt(scb_s, 0x0080U);
776 goto unpin;
777 }
778 vsie_page->itdba_gpa = gpa;
779 scb_s->itdba = hpa;
780 }
781
782 gpa = READ_ONCE(scb_o->gvrd) & ~0x1ffUL;
783 if (gpa && (scb_s->eca & ECA_VX) && !(scb_s->ecd & ECD_HOSTREGMGMT)) {
784 if (gpa < 2 * PAGE_SIZE) {
785 rc = set_validity_icpt(scb_s, 0x1310U);
786 goto unpin;
787 }
788 /*
789 * 512 bytes vector registers cannot cross page boundaries
790 * if this block gets bigger, we have to shadow it.
791 */
792 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
793 if (rc) {
794 rc = set_validity_icpt(scb_s, 0x1310U);
795 goto unpin;
796 }
797 vsie_page->gvrd_gpa = gpa;
798 scb_s->gvrd = hpa;
799 }
800
801 gpa = READ_ONCE(scb_o->riccbd) & ~0x3fUL;
802 if (gpa && (scb_s->ecb3 & ECB3_RI)) {
803 if (gpa < 2 * PAGE_SIZE) {
804 rc = set_validity_icpt(scb_s, 0x0043U);
805 goto unpin;
806 }
807 /* 64 bytes cannot cross page boundaries */
808 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
809 if (rc) {
810 rc = set_validity_icpt(scb_s, 0x0043U);
811 goto unpin;
812 }
813 /* Validity 0x0044 will be checked by SIE */
814 vsie_page->riccbd_gpa = gpa;
815 scb_s->riccbd = hpa;
816 }
817 if (((scb_s->ecb & ECB_GS) && !(scb_s->ecd & ECD_HOSTREGMGMT)) ||
818 (scb_s->ecd & ECD_ETOKENF)) {
819 unsigned long sdnxc;
820
821 gpa = READ_ONCE(scb_o->sdnxo) & ~0xfUL;
822 sdnxc = READ_ONCE(scb_o->sdnxo) & 0xfUL;
823 if (!gpa || gpa < 2 * PAGE_SIZE) {
824 rc = set_validity_icpt(scb_s, 0x10b0U);
825 goto unpin;
826 }
827 if (sdnxc < 6 || sdnxc > 12) {
828 rc = set_validity_icpt(scb_s, 0x10b1U);
829 goto unpin;
830 }
831 if (gpa & ((1 << sdnxc) - 1)) {
832 rc = set_validity_icpt(scb_s, 0x10b2U);
833 goto unpin;
834 }
835 /* Due to alignment rules (checked above) this cannot
836 * cross page boundaries
837 */
838 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
839 if (rc) {
840 rc = set_validity_icpt(scb_s, 0x10b0U);
841 goto unpin;
842 }
843 vsie_page->sdnx_gpa = gpa;
844 scb_s->sdnxo = hpa | sdnxc;
845 }
846 return 0;
847 unpin:
848 unpin_blocks(vcpu, vsie_page);
849 return rc;
850 }
851
852 /* unpin the scb provided by guest 2, marking it as dirty */
unpin_scb(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page,gpa_t gpa)853 static void unpin_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page,
854 gpa_t gpa)
855 {
856 hpa_t hpa = (hpa_t) vsie_page->scb_o;
857
858 if (hpa)
859 unpin_guest_page(vcpu->kvm, gpa, hpa);
860 vsie_page->scb_o = NULL;
861 }
862
863 /*
864 * Pin the scb at gpa provided by guest 2 at vsie_page->scb_o.
865 *
866 * Returns: - 0 if the scb was pinned.
867 * - > 0 if control has to be given to guest 2
868 */
pin_scb(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page,gpa_t gpa)869 static int pin_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page,
870 gpa_t gpa)
871 {
872 hpa_t hpa;
873 int rc;
874
875 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
876 if (rc) {
877 rc = kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
878 WARN_ON_ONCE(rc);
879 return 1;
880 }
881 vsie_page->scb_o = phys_to_virt(hpa);
882 return 0;
883 }
884
885 /*
886 * Inject a fault into guest 2.
887 *
888 * Returns: - > 0 if control has to be given to guest 2
889 * < 0 if an error occurred during injection.
890 */
inject_fault(struct kvm_vcpu * vcpu,__u16 code,__u64 vaddr,bool write_flag)891 static int inject_fault(struct kvm_vcpu *vcpu, __u16 code, __u64 vaddr,
892 bool write_flag)
893 {
894 struct kvm_s390_pgm_info pgm = {
895 .code = code,
896 .trans_exc_code =
897 /* 0-51: virtual address */
898 (vaddr & 0xfffffffffffff000UL) |
899 /* 52-53: store / fetch */
900 (((unsigned int) !write_flag) + 1) << 10,
901 /* 62-63: asce id (always primary == 0) */
902 .exc_access_id = 0, /* always primary */
903 .op_access_id = 0, /* not MVPG */
904 };
905 int rc;
906
907 if (code == PGM_PROTECTION)
908 pgm.trans_exc_code |= 0x4UL;
909
910 rc = kvm_s390_inject_prog_irq(vcpu, &pgm);
911 return rc ? rc : 1;
912 }
913
914 /*
915 * Handle a fault during vsie execution on a gmap shadow.
916 *
917 * Returns: - 0 if the fault was resolved
918 * - > 0 if control has to be given to guest 2
919 * - < 0 if an error occurred
920 */
handle_fault(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page)921 static int handle_fault(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
922 {
923 int rc;
924
925 if (current->thread.gmap_int_code == PGM_PROTECTION)
926 /* we can directly forward all protection exceptions */
927 return inject_fault(vcpu, PGM_PROTECTION,
928 current->thread.gmap_addr, 1);
929
930 rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap,
931 current->thread.gmap_addr, NULL);
932 if (rc > 0) {
933 rc = inject_fault(vcpu, rc,
934 current->thread.gmap_addr,
935 current->thread.gmap_write_flag);
936 if (rc >= 0)
937 vsie_page->fault_addr = current->thread.gmap_addr;
938 }
939 return rc;
940 }
941
942 /*
943 * Retry the previous fault that required guest 2 intervention. This avoids
944 * one superfluous SIE re-entry and direct exit.
945 *
946 * Will ignore any errors. The next SIE fault will do proper fault handling.
947 */
handle_last_fault(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page)948 static void handle_last_fault(struct kvm_vcpu *vcpu,
949 struct vsie_page *vsie_page)
950 {
951 if (vsie_page->fault_addr)
952 kvm_s390_shadow_fault(vcpu, vsie_page->gmap,
953 vsie_page->fault_addr, NULL);
954 vsie_page->fault_addr = 0;
955 }
956
clear_vsie_icpt(struct vsie_page * vsie_page)957 static inline void clear_vsie_icpt(struct vsie_page *vsie_page)
958 {
959 vsie_page->scb_s.icptcode = 0;
960 }
961
962 /* rewind the psw and clear the vsie icpt, so we can retry execution */
retry_vsie_icpt(struct vsie_page * vsie_page)963 static void retry_vsie_icpt(struct vsie_page *vsie_page)
964 {
965 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
966 int ilen = insn_length(scb_s->ipa >> 8);
967
968 /* take care of EXECUTE instructions */
969 if (scb_s->icptstatus & 1) {
970 ilen = (scb_s->icptstatus >> 4) & 0x6;
971 if (!ilen)
972 ilen = 4;
973 }
974 scb_s->gpsw.addr = __rewind_psw(scb_s->gpsw, ilen);
975 clear_vsie_icpt(vsie_page);
976 }
977
978 /*
979 * Try to shadow + enable the guest 2 provided facility list.
980 * Retry instruction execution if enabled for and provided by guest 2.
981 *
982 * Returns: - 0 if handled (retry or guest 2 icpt)
983 * - > 0 if control has to be given to guest 2
984 */
handle_stfle(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page)985 static int handle_stfle(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
986 {
987 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
988 __u32 fac = READ_ONCE(vsie_page->scb_o->fac);
989
990 /*
991 * Alternate-STFLE-Interpretive-Execution facilities are not supported
992 * -> format-0 flcb
993 */
994 if (fac && test_kvm_facility(vcpu->kvm, 7)) {
995 retry_vsie_icpt(vsie_page);
996 /*
997 * The facility list origin (FLO) is in bits 1 - 28 of the FLD
998 * so we need to mask here before reading.
999 */
1000 fac = fac & 0x7ffffff8U;
1001 /*
1002 * format-0 -> size of nested guest's facility list == guest's size
1003 * guest's size == host's size, since STFLE is interpretatively executed
1004 * using a format-0 for the guest, too.
1005 */
1006 if (read_guest_real(vcpu, fac, &vsie_page->fac,
1007 stfle_size() * sizeof(u64)))
1008 return set_validity_icpt(scb_s, 0x1090U);
1009 scb_s->fac = (u32)virt_to_phys(&vsie_page->fac);
1010 }
1011 return 0;
1012 }
1013
1014 /*
1015 * Get a register for a nested guest.
1016 * @vcpu the vcpu of the guest
1017 * @vsie_page the vsie_page for the nested guest
1018 * @reg the register number, the upper 4 bits are ignored.
1019 * returns: the value of the register.
1020 */
vsie_get_register(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page,u8 reg)1021 static u64 vsie_get_register(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page, u8 reg)
1022 {
1023 /* no need to validate the parameter and/or perform error handling */
1024 reg &= 0xf;
1025 switch (reg) {
1026 case 15:
1027 return vsie_page->scb_s.gg15;
1028 case 14:
1029 return vsie_page->scb_s.gg14;
1030 default:
1031 return vcpu->run->s.regs.gprs[reg];
1032 }
1033 }
1034
vsie_handle_mvpg(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page)1035 static int vsie_handle_mvpg(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
1036 {
1037 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
1038 unsigned long pei_dest, pei_src, src, dest, mask, prefix;
1039 u64 *pei_block = &vsie_page->scb_o->mcic;
1040 int edat, rc_dest, rc_src;
1041 union ctlreg0 cr0;
1042
1043 cr0.val = vcpu->arch.sie_block->gcr[0];
1044 edat = cr0.edat && test_kvm_facility(vcpu->kvm, 8);
1045 mask = _kvm_s390_logical_to_effective(&scb_s->gpsw, PAGE_MASK);
1046 prefix = scb_s->prefix << GUEST_PREFIX_SHIFT;
1047
1048 dest = vsie_get_register(vcpu, vsie_page, scb_s->ipb >> 20) & mask;
1049 dest = _kvm_s390_real_to_abs(prefix, dest) + scb_s->mso;
1050 src = vsie_get_register(vcpu, vsie_page, scb_s->ipb >> 16) & mask;
1051 src = _kvm_s390_real_to_abs(prefix, src) + scb_s->mso;
1052
1053 rc_dest = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, dest, &pei_dest);
1054 rc_src = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, src, &pei_src);
1055 /*
1056 * Either everything went well, or something non-critical went wrong
1057 * e.g. because of a race. In either case, simply retry.
1058 */
1059 if (rc_dest == -EAGAIN || rc_src == -EAGAIN || (!rc_dest && !rc_src)) {
1060 retry_vsie_icpt(vsie_page);
1061 return -EAGAIN;
1062 }
1063 /* Something more serious went wrong, propagate the error */
1064 if (rc_dest < 0)
1065 return rc_dest;
1066 if (rc_src < 0)
1067 return rc_src;
1068
1069 /* The only possible suppressing exception: just deliver it */
1070 if (rc_dest == PGM_TRANSLATION_SPEC || rc_src == PGM_TRANSLATION_SPEC) {
1071 clear_vsie_icpt(vsie_page);
1072 rc_dest = kvm_s390_inject_program_int(vcpu, PGM_TRANSLATION_SPEC);
1073 WARN_ON_ONCE(rc_dest);
1074 return 1;
1075 }
1076
1077 /*
1078 * Forward the PEI intercept to the guest if it was a page fault, or
1079 * also for segment and region table faults if EDAT applies.
1080 */
1081 if (edat) {
1082 rc_dest = rc_dest == PGM_ASCE_TYPE ? rc_dest : 0;
1083 rc_src = rc_src == PGM_ASCE_TYPE ? rc_src : 0;
1084 } else {
1085 rc_dest = rc_dest != PGM_PAGE_TRANSLATION ? rc_dest : 0;
1086 rc_src = rc_src != PGM_PAGE_TRANSLATION ? rc_src : 0;
1087 }
1088 if (!rc_dest && !rc_src) {
1089 pei_block[0] = pei_dest;
1090 pei_block[1] = pei_src;
1091 return 1;
1092 }
1093
1094 retry_vsie_icpt(vsie_page);
1095
1096 /*
1097 * The host has edat, and the guest does not, or it was an ASCE type
1098 * exception. The host needs to inject the appropriate DAT interrupts
1099 * into the guest.
1100 */
1101 if (rc_dest)
1102 return inject_fault(vcpu, rc_dest, dest, 1);
1103 return inject_fault(vcpu, rc_src, src, 0);
1104 }
1105
1106 /*
1107 * Run the vsie on a shadow scb and a shadow gmap, without any further
1108 * sanity checks, handling SIE faults.
1109 *
1110 * Returns: - 0 everything went fine
1111 * - > 0 if control has to be given to guest 2
1112 * - < 0 if an error occurred
1113 */
do_vsie_run(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page)1114 static int do_vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
1115 __releases(vcpu->kvm->srcu)
1116 __acquires(vcpu->kvm->srcu)
1117 {
1118 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
1119 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
1120 int guest_bp_isolation;
1121 int rc = 0;
1122
1123 handle_last_fault(vcpu, vsie_page);
1124
1125 kvm_vcpu_srcu_read_unlock(vcpu);
1126
1127 /* save current guest state of bp isolation override */
1128 guest_bp_isolation = test_thread_flag(TIF_ISOLATE_BP_GUEST);
1129
1130 /*
1131 * The guest is running with BPBC, so we have to force it on for our
1132 * nested guest. This is done by enabling BPBC globally, so the BPBC
1133 * control in the SCB (which the nested guest can modify) is simply
1134 * ignored.
1135 */
1136 if (test_kvm_facility(vcpu->kvm, 82) &&
1137 vcpu->arch.sie_block->fpf & FPF_BPBC)
1138 set_thread_flag(TIF_ISOLATE_BP_GUEST);
1139
1140 local_irq_disable();
1141 guest_enter_irqoff();
1142 local_irq_enable();
1143
1144 /*
1145 * Simulate a SIE entry of the VCPU (see sie64a), so VCPU blocking
1146 * and VCPU requests also hinder the vSIE from running and lead
1147 * to an immediate exit. kvm_s390_vsie_kick() has to be used to
1148 * also kick the vSIE.
1149 */
1150 vcpu->arch.sie_block->prog0c |= PROG_IN_SIE;
1151 barrier();
1152 if (!kvm_s390_vcpu_sie_inhibited(vcpu))
1153 rc = sie64a(scb_s, vcpu->run->s.regs.gprs, gmap_get_enabled()->asce);
1154 barrier();
1155 vcpu->arch.sie_block->prog0c &= ~PROG_IN_SIE;
1156
1157 local_irq_disable();
1158 guest_exit_irqoff();
1159 local_irq_enable();
1160
1161 /* restore guest state for bp isolation override */
1162 if (!guest_bp_isolation)
1163 clear_thread_flag(TIF_ISOLATE_BP_GUEST);
1164
1165 kvm_vcpu_srcu_read_lock(vcpu);
1166
1167 if (rc == -EINTR) {
1168 VCPU_EVENT(vcpu, 3, "%s", "machine check");
1169 kvm_s390_reinject_machine_check(vcpu, &vsie_page->mcck_info);
1170 return 0;
1171 }
1172
1173 if (rc > 0)
1174 rc = 0; /* we could still have an icpt */
1175 else if (rc == -EFAULT)
1176 return handle_fault(vcpu, vsie_page);
1177
1178 switch (scb_s->icptcode) {
1179 case ICPT_INST:
1180 if (scb_s->ipa == 0xb2b0)
1181 rc = handle_stfle(vcpu, vsie_page);
1182 break;
1183 case ICPT_STOP:
1184 /* stop not requested by g2 - must have been a kick */
1185 if (!(atomic_read(&scb_o->cpuflags) & CPUSTAT_STOP_INT))
1186 clear_vsie_icpt(vsie_page);
1187 break;
1188 case ICPT_VALIDITY:
1189 if ((scb_s->ipa & 0xf000) != 0xf000)
1190 scb_s->ipa += 0x1000;
1191 break;
1192 case ICPT_PARTEXEC:
1193 if (scb_s->ipa == 0xb254)
1194 rc = vsie_handle_mvpg(vcpu, vsie_page);
1195 break;
1196 }
1197 return rc;
1198 }
1199
release_gmap_shadow(struct vsie_page * vsie_page)1200 static void release_gmap_shadow(struct vsie_page *vsie_page)
1201 {
1202 if (vsie_page->gmap)
1203 gmap_put(vsie_page->gmap);
1204 WRITE_ONCE(vsie_page->gmap, NULL);
1205 prefix_unmapped(vsie_page);
1206 }
1207
acquire_gmap_shadow(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page)1208 static int acquire_gmap_shadow(struct kvm_vcpu *vcpu,
1209 struct vsie_page *vsie_page)
1210 {
1211 unsigned long asce;
1212 union ctlreg0 cr0;
1213 struct gmap *gmap;
1214 int edat;
1215
1216 asce = vcpu->arch.sie_block->gcr[1];
1217 cr0.val = vcpu->arch.sie_block->gcr[0];
1218 edat = cr0.edat && test_kvm_facility(vcpu->kvm, 8);
1219 edat += edat && test_kvm_facility(vcpu->kvm, 78);
1220
1221 /*
1222 * ASCE or EDAT could have changed since last icpt, or the gmap
1223 * we're holding has been unshadowed. If the gmap is still valid,
1224 * we can safely reuse it.
1225 */
1226 if (vsie_page->gmap && gmap_shadow_valid(vsie_page->gmap, asce, edat)) {
1227 vcpu->kvm->stat.gmap_shadow_reuse++;
1228 return 0;
1229 }
1230
1231 /* release the old shadow - if any, and mark the prefix as unmapped */
1232 release_gmap_shadow(vsie_page);
1233 gmap = gmap_shadow(vcpu->arch.gmap, asce, edat);
1234 if (IS_ERR(gmap))
1235 return PTR_ERR(gmap);
1236 vcpu->kvm->stat.gmap_shadow_create++;
1237 WRITE_ONCE(vsie_page->gmap, gmap);
1238 return 0;
1239 }
1240
1241 /*
1242 * Register the shadow scb at the VCPU, e.g. for kicking out of vsie.
1243 */
register_shadow_scb(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page)1244 static void register_shadow_scb(struct kvm_vcpu *vcpu,
1245 struct vsie_page *vsie_page)
1246 {
1247 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
1248
1249 WRITE_ONCE(vcpu->arch.vsie_block, &vsie_page->scb_s);
1250 /*
1251 * External calls have to lead to a kick of the vcpu and
1252 * therefore the vsie -> Simulate Wait state.
1253 */
1254 kvm_s390_set_cpuflags(vcpu, CPUSTAT_WAIT);
1255 /*
1256 * We have to adjust the g3 epoch by the g2 epoch. The epoch will
1257 * automatically be adjusted on tod clock changes via kvm_sync_clock.
1258 */
1259 preempt_disable();
1260 scb_s->epoch += vcpu->kvm->arch.epoch;
1261
1262 if (scb_s->ecd & ECD_MEF) {
1263 scb_s->epdx += vcpu->kvm->arch.epdx;
1264 if (scb_s->epoch < vcpu->kvm->arch.epoch)
1265 scb_s->epdx += 1;
1266 }
1267
1268 preempt_enable();
1269 }
1270
1271 /*
1272 * Unregister a shadow scb from a VCPU.
1273 */
unregister_shadow_scb(struct kvm_vcpu * vcpu)1274 static void unregister_shadow_scb(struct kvm_vcpu *vcpu)
1275 {
1276 kvm_s390_clear_cpuflags(vcpu, CPUSTAT_WAIT);
1277 WRITE_ONCE(vcpu->arch.vsie_block, NULL);
1278 }
1279
1280 /*
1281 * Run the vsie on a shadowed scb, managing the gmap shadow, handling
1282 * prefix pages and faults.
1283 *
1284 * Returns: - 0 if no errors occurred
1285 * - > 0 if control has to be given to guest 2
1286 * - -ENOMEM if out of memory
1287 */
vsie_run(struct kvm_vcpu * vcpu,struct vsie_page * vsie_page)1288 static int vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
1289 {
1290 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
1291 int rc = 0;
1292
1293 while (1) {
1294 rc = acquire_gmap_shadow(vcpu, vsie_page);
1295 if (!rc)
1296 rc = map_prefix(vcpu, vsie_page);
1297 if (!rc) {
1298 gmap_enable(vsie_page->gmap);
1299 update_intervention_requests(vsie_page);
1300 rc = do_vsie_run(vcpu, vsie_page);
1301 gmap_enable(vcpu->arch.gmap);
1302 }
1303 atomic_andnot(PROG_BLOCK_SIE, &scb_s->prog20);
1304
1305 if (rc == -EAGAIN)
1306 rc = 0;
1307
1308 /*
1309 * Exit the loop if the guest needs to process the intercept
1310 */
1311 if (rc || scb_s->icptcode)
1312 break;
1313
1314 /*
1315 * Exit the loop if the host needs to process an intercept,
1316 * but rewind the PSW to re-enter SIE once that's completed
1317 * instead of passing a "no action" intercept to the guest.
1318 */
1319 if (signal_pending(current) ||
1320 kvm_s390_vcpu_has_irq(vcpu, 0) ||
1321 kvm_s390_vcpu_sie_inhibited(vcpu)) {
1322 kvm_s390_rewind_psw(vcpu, 4);
1323 break;
1324 }
1325 cond_resched();
1326 }
1327
1328 if (rc == -EFAULT) {
1329 /*
1330 * Addressing exceptions are always presentes as intercepts.
1331 * As addressing exceptions are suppressing and our guest 3 PSW
1332 * points at the responsible instruction, we have to
1333 * forward the PSW and set the ilc. If we can't read guest 3
1334 * instruction, we can use an arbitrary ilc. Let's always use
1335 * ilen = 4 for now, so we can avoid reading in guest 3 virtual
1336 * memory. (we could also fake the shadow so the hardware
1337 * handles it).
1338 */
1339 scb_s->icptcode = ICPT_PROGI;
1340 scb_s->iprcc = PGM_ADDRESSING;
1341 scb_s->pgmilc = 4;
1342 scb_s->gpsw.addr = __rewind_psw(scb_s->gpsw, 4);
1343 rc = 1;
1344 }
1345 return rc;
1346 }
1347
1348 /*
1349 * Get or create a vsie page for a scb address.
1350 *
1351 * Returns: - address of a vsie page (cached or new one)
1352 * - NULL if the same scb address is already used by another VCPU
1353 * - ERR_PTR(-ENOMEM) if out of memory
1354 */
get_vsie_page(struct kvm * kvm,unsigned long addr)1355 static struct vsie_page *get_vsie_page(struct kvm *kvm, unsigned long addr)
1356 {
1357 struct vsie_page *vsie_page;
1358 struct page *page;
1359 int nr_vcpus;
1360
1361 rcu_read_lock();
1362 page = radix_tree_lookup(&kvm->arch.vsie.addr_to_page, addr >> 9);
1363 rcu_read_unlock();
1364 if (page) {
1365 if (page_ref_inc_return(page) == 2)
1366 return page_to_virt(page);
1367 page_ref_dec(page);
1368 }
1369
1370 /*
1371 * We want at least #online_vcpus shadows, so every VCPU can execute
1372 * the VSIE in parallel.
1373 */
1374 nr_vcpus = atomic_read(&kvm->online_vcpus);
1375
1376 mutex_lock(&kvm->arch.vsie.mutex);
1377 if (kvm->arch.vsie.page_count < nr_vcpus) {
1378 page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO | GFP_DMA);
1379 if (!page) {
1380 mutex_unlock(&kvm->arch.vsie.mutex);
1381 return ERR_PTR(-ENOMEM);
1382 }
1383 page_ref_inc(page);
1384 kvm->arch.vsie.pages[kvm->arch.vsie.page_count] = page;
1385 kvm->arch.vsie.page_count++;
1386 } else {
1387 /* reuse an existing entry that belongs to nobody */
1388 while (true) {
1389 page = kvm->arch.vsie.pages[kvm->arch.vsie.next];
1390 if (page_ref_inc_return(page) == 2)
1391 break;
1392 page_ref_dec(page);
1393 kvm->arch.vsie.next++;
1394 kvm->arch.vsie.next %= nr_vcpus;
1395 }
1396 radix_tree_delete(&kvm->arch.vsie.addr_to_page, page->index >> 9);
1397 }
1398 page->index = addr;
1399 /* double use of the same address */
1400 if (radix_tree_insert(&kvm->arch.vsie.addr_to_page, addr >> 9, page)) {
1401 page_ref_dec(page);
1402 mutex_unlock(&kvm->arch.vsie.mutex);
1403 return NULL;
1404 }
1405 mutex_unlock(&kvm->arch.vsie.mutex);
1406
1407 vsie_page = page_to_virt(page);
1408 memset(&vsie_page->scb_s, 0, sizeof(struct kvm_s390_sie_block));
1409 release_gmap_shadow(vsie_page);
1410 vsie_page->fault_addr = 0;
1411 vsie_page->scb_s.ihcpu = 0xffffU;
1412 return vsie_page;
1413 }
1414
1415 /* put a vsie page acquired via get_vsie_page */
put_vsie_page(struct kvm * kvm,struct vsie_page * vsie_page)1416 static void put_vsie_page(struct kvm *kvm, struct vsie_page *vsie_page)
1417 {
1418 struct page *page = pfn_to_page(__pa(vsie_page) >> PAGE_SHIFT);
1419
1420 page_ref_dec(page);
1421 }
1422
kvm_s390_handle_vsie(struct kvm_vcpu * vcpu)1423 int kvm_s390_handle_vsie(struct kvm_vcpu *vcpu)
1424 {
1425 struct vsie_page *vsie_page;
1426 unsigned long scb_addr;
1427 int rc;
1428
1429 vcpu->stat.instruction_sie++;
1430 if (!test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_SIEF2))
1431 return -EOPNOTSUPP;
1432 if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
1433 return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
1434
1435 BUILD_BUG_ON(sizeof(struct vsie_page) != PAGE_SIZE);
1436 scb_addr = kvm_s390_get_base_disp_s(vcpu, NULL);
1437
1438 /* 512 byte alignment */
1439 if (unlikely(scb_addr & 0x1ffUL))
1440 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
1441
1442 if (signal_pending(current) || kvm_s390_vcpu_has_irq(vcpu, 0) ||
1443 kvm_s390_vcpu_sie_inhibited(vcpu)) {
1444 kvm_s390_rewind_psw(vcpu, 4);
1445 return 0;
1446 }
1447
1448 vsie_page = get_vsie_page(vcpu->kvm, scb_addr);
1449 if (IS_ERR(vsie_page))
1450 return PTR_ERR(vsie_page);
1451 else if (!vsie_page)
1452 /* double use of sie control block - simply do nothing */
1453 return 0;
1454
1455 rc = pin_scb(vcpu, vsie_page, scb_addr);
1456 if (rc)
1457 goto out_put;
1458 rc = shadow_scb(vcpu, vsie_page);
1459 if (rc)
1460 goto out_unpin_scb;
1461 rc = pin_blocks(vcpu, vsie_page);
1462 if (rc)
1463 goto out_unshadow;
1464 register_shadow_scb(vcpu, vsie_page);
1465 rc = vsie_run(vcpu, vsie_page);
1466 unregister_shadow_scb(vcpu);
1467 unpin_blocks(vcpu, vsie_page);
1468 out_unshadow:
1469 unshadow_scb(vcpu, vsie_page);
1470 out_unpin_scb:
1471 unpin_scb(vcpu, vsie_page, scb_addr);
1472 out_put:
1473 put_vsie_page(vcpu->kvm, vsie_page);
1474
1475 return rc < 0 ? rc : 0;
1476 }
1477
1478 /* Init the vsie data structures. To be called when a vm is initialized. */
kvm_s390_vsie_init(struct kvm * kvm)1479 void kvm_s390_vsie_init(struct kvm *kvm)
1480 {
1481 mutex_init(&kvm->arch.vsie.mutex);
1482 INIT_RADIX_TREE(&kvm->arch.vsie.addr_to_page, GFP_KERNEL_ACCOUNT);
1483 }
1484
1485 /* Destroy the vsie data structures. To be called when a vm is destroyed. */
kvm_s390_vsie_destroy(struct kvm * kvm)1486 void kvm_s390_vsie_destroy(struct kvm *kvm)
1487 {
1488 struct vsie_page *vsie_page;
1489 struct page *page;
1490 int i;
1491
1492 mutex_lock(&kvm->arch.vsie.mutex);
1493 for (i = 0; i < kvm->arch.vsie.page_count; i++) {
1494 page = kvm->arch.vsie.pages[i];
1495 kvm->arch.vsie.pages[i] = NULL;
1496 vsie_page = page_to_virt(page);
1497 release_gmap_shadow(vsie_page);
1498 /* free the radix tree entry */
1499 radix_tree_delete(&kvm->arch.vsie.addr_to_page, page->index >> 9);
1500 __free_page(page);
1501 }
1502 kvm->arch.vsie.page_count = 0;
1503 mutex_unlock(&kvm->arch.vsie.mutex);
1504 }
1505
kvm_s390_vsie_kick(struct kvm_vcpu * vcpu)1506 void kvm_s390_vsie_kick(struct kvm_vcpu *vcpu)
1507 {
1508 struct kvm_s390_sie_block *scb = READ_ONCE(vcpu->arch.vsie_block);
1509
1510 /*
1511 * Even if the VCPU lets go of the shadow sie block reference, it is
1512 * still valid in the cache. So we can safely kick it.
1513 */
1514 if (scb) {
1515 atomic_or(PROG_BLOCK_SIE, &scb->prog20);
1516 if (scb->prog0c & PROG_IN_SIE)
1517 atomic_or(CPUSTAT_STOP_INT, &scb->cpuflags);
1518 }
1519 }
1520