arch/s390/kvm/vsie.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * kvm nested virtualization support for s390x
   4  *
   5  * Copyright IBM Corp. 2016, 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
  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 /* Copy to APCB FORMAT1 from APCB FORMAT0 */
 139 static int setup_apcb10(struct kvm_vcpu *vcpu, struct kvm_s390_apcb1 *apcb_s,
 140                         unsigned long apcb_o, struct kvm_s390_apcb1 *apcb_h)
 141 {
 142         struct kvm_s390_apcb0 tmp;
 143
 144         if (read_guest_real(vcpu, apcb_o, &tmp, sizeof(struct kvm_s390_apcb0)))
 145                 return -EFAULT;
 146
 147         apcb_s->apm[0] = apcb_h->apm[0] & tmp.apm[0];
 148         apcb_s->aqm[0] = apcb_h->aqm[0] & tmp.aqm[0] & 0xffff000000000000UL;
 149         apcb_s->adm[0] = apcb_h->adm[0] & tmp.adm[0] & 0xffff000000000000UL;
 150
 151         return 0;
 152
 153 }
 154
 155 /**
 156  * setup_apcb00 - Copy to APCB FORMAT0 from APCB FORMAT0
 157  * @vcpu: pointer to the virtual CPU
 158  * @apcb_s: pointer to start of apcb in the shadow crycb
 159  * @apcb_o: pointer to start of original apcb in the guest2
 160  * @apcb_h: pointer to start of apcb in the guest1
 161  *
 162  * Returns 0 and -EFAULT on error reading guest apcb
 163  */
 164 static int setup_apcb00(struct kvm_vcpu *vcpu, unsigned long *apcb_s,
 165                         unsigned long apcb_o, unsigned long *apcb_h)
 166 {
 167         if (read_guest_real(vcpu, apcb_o, apcb_s,
 168                             sizeof(struct kvm_s390_apcb0)))
 169                 return -EFAULT;
 170
 171         bitmap_and(apcb_s, apcb_s, apcb_h, sizeof(struct kvm_s390_apcb0));
 172
 173         return 0;
 174 }
 175
 176 /**
 177  * setup_apcb11 - Copy the FORMAT1 APCB from the guest to the shadow CRYCB
 178  * @vcpu: pointer to the virtual CPU
 179  * @apcb_s: pointer to start of apcb in the shadow crycb
 180  * @apcb_o: pointer to start of original guest apcb
 181  * @apcb_h: pointer to start of apcb in the host
 182  *
 183  * Returns 0 and -EFAULT on error reading guest apcb
 184  */
 185 static int setup_apcb11(struct kvm_vcpu *vcpu, unsigned long *apcb_s,
 186                         unsigned long apcb_o,
 187                         unsigned long *apcb_h)
 188 {
 189         if (read_guest_real(vcpu, apcb_o, apcb_s,
 190                             sizeof(struct kvm_s390_apcb1)))
 191                 return -EFAULT;
 192
 193         bitmap_and(apcb_s, apcb_s, apcb_h, sizeof(struct kvm_s390_apcb1));
 194
 195         return 0;
 196 }
 197
 198 /**
 199  * setup_apcb - Create a shadow copy of the apcb.
 200  * @vcpu: pointer to the virtual CPU
 201  * @crycb_s: pointer to shadow crycb
 202  * @crycb_o: pointer to original guest crycb
 203  * @crycb_h: pointer to the host crycb
 204  * @fmt_o: format of the original guest crycb.
 205  * @fmt_h: format of the host crycb.
 206  *
 207  * Checks the compatibility between the guest and host crycb and calls the
 208  * appropriate copy function.
 209  *
 210  * Return 0 or an error number if the guest and host crycb are incompatible.
 211  */
 212 static int setup_apcb(struct kvm_vcpu *vcpu, struct kvm_s390_crypto_cb *crycb_s,
 213                const u32 crycb_o,
 214                struct kvm_s390_crypto_cb *crycb_h,
 215                int fmt_o, int fmt_h)
 216 {
 217         struct kvm_s390_crypto_cb *crycb;
 218
 219         crycb = (struct kvm_s390_crypto_cb *) (unsigned long)crycb_o;
 220
 221         switch (fmt_o) {
 222         case CRYCB_FORMAT2:
 223                 if ((crycb_o & PAGE_MASK) != ((crycb_o + 256) & PAGE_MASK))
 224                         return -EACCES;
 225                 if (fmt_h != CRYCB_FORMAT2)
 226                         return -EINVAL;
 227                 return setup_apcb11(vcpu, (unsigned long *)&crycb_s->apcb1,
 228                                     (unsigned long) &crycb->apcb1,
 229                                     (unsigned long *)&crycb_h->apcb1);
 230         case CRYCB_FORMAT1:
 231                 switch (fmt_h) {
 232                 case CRYCB_FORMAT2:
 233                         return setup_apcb10(vcpu, &crycb_s->apcb1,
 234                                             (unsigned long) &crycb->apcb0,
 235                                             &crycb_h->apcb1);
 236                 case CRYCB_FORMAT1:
 237                         return setup_apcb00(vcpu,
 238                                             (unsigned long *) &crycb_s->apcb0,
 239                                             (unsigned long) &crycb->apcb0,
 240                                             (unsigned long *) &crycb_h->apcb0);
 241                 }
 242                 break;
 243         case CRYCB_FORMAT0:
 244                 if ((crycb_o & PAGE_MASK) != ((crycb_o + 32) & PAGE_MASK))
 245                         return -EACCES;
 246
 247                 switch (fmt_h) {
 248                 case CRYCB_FORMAT2:
 249                         return setup_apcb10(vcpu, &crycb_s->apcb1,
 250                                             (unsigned long) &crycb->apcb0,
 251                                             &crycb_h->apcb1);
 252                 case CRYCB_FORMAT1:
 253                 case CRYCB_FORMAT0:
 254                         return setup_apcb00(vcpu,
 255                                             (unsigned long *) &crycb_s->apcb0,
 256                                             (unsigned long) &crycb->apcb0,
 257                                             (unsigned long *) &crycb_h->apcb0);
 258                 }
 259         }
 260         return -EINVAL;
 261 }
 262
 263 /**
 264  * shadow_crycb - Create a shadow copy of the crycb block
 265  * @vcpu: a pointer to the virtual CPU
 266  * @vsie_page: a pointer to internal date used for the vSIE
 267  *
 268  * Create a shadow copy of the crycb block and setup key wrapping, if
 269  * requested for guest 3 and enabled for guest 2.
 270  *
 271  * We accept format-1 or format-2, but we convert format-1 into format-2
 272  * in the shadow CRYCB.
 273  * Using format-2 enables the firmware to choose the right format when
 274  * scheduling the SIE.
 275  * There is nothing to do for format-0.
 276  *
 277  * This function centralize the issuing of set_validity_icpt() for all
 278  * the subfunctions working on the crycb.
 279  *
 280  * Returns: - 0 if shadowed or nothing to do
 281  *          - > 0 if control has to be given to guest 2
 282  */
 283 static int shadow_crycb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
 284 {
 285         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
 286         struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
 287         const uint32_t crycbd_o = READ_ONCE(scb_o->crycbd);
 288         const u32 crycb_addr = crycbd_o & 0x7ffffff8U;
 289         unsigned long *b1, *b2;
 290         u8 ecb3_flags;
 291         u32 ecd_flags;
 292         int apie_h;
 293         int apie_s;
 294         int key_msk = test_kvm_facility(vcpu->kvm, 76);
 295         int fmt_o = crycbd_o & CRYCB_FORMAT_MASK;
 296         int fmt_h = vcpu->arch.sie_block->crycbd & CRYCB_FORMAT_MASK;
 297         int ret = 0;
 298
 299         scb_s->crycbd = 0;
 300
 301         apie_h = vcpu->arch.sie_block->eca & ECA_APIE;
 302         apie_s = apie_h & scb_o->eca;
 303         if (!apie_s && (!key_msk || (fmt_o == CRYCB_FORMAT0)))
 304                 return 0;
 305
 306         if (!crycb_addr)
 307                 return set_validity_icpt(scb_s, 0x0039U);
 308
 309         if (fmt_o == CRYCB_FORMAT1)
 310                 if ((crycb_addr & PAGE_MASK) !=
 311                     ((crycb_addr + 128) & PAGE_MASK))
 312                         return set_validity_icpt(scb_s, 0x003CU);
 313
 314         if (apie_s) {
 315                 ret = setup_apcb(vcpu, &vsie_page->crycb, crycb_addr,
 316                                  vcpu->kvm->arch.crypto.crycb,
 317                                  fmt_o, fmt_h);
 318                 if (ret)
 319                         goto end;
 320                 scb_s->eca |= scb_o->eca & ECA_APIE;
 321         }
 322
 323         /* we may only allow it if enabled for guest 2 */
 324         ecb3_flags = scb_o->ecb3 & vcpu->arch.sie_block->ecb3 &
 325                      (ECB3_AES | ECB3_DEA);
 326         ecd_flags = scb_o->ecd & vcpu->arch.sie_block->ecd & ECD_ECC;
 327         if (!ecb3_flags && !ecd_flags)
 328                 goto end;
 329
 330         /* copy only the wrapping keys */
 331         if (read_guest_real(vcpu, crycb_addr + 72,
 332                             vsie_page->crycb.dea_wrapping_key_mask, 56))
 333                 return set_validity_icpt(scb_s, 0x0035U);
 334
 335         scb_s->ecb3 |= ecb3_flags;
 336         scb_s->ecd |= ecd_flags;
 337
 338         /* xor both blocks in one run */
 339         b1 = (unsigned long *) vsie_page->crycb.dea_wrapping_key_mask;
 340         b2 = (unsigned long *)
 341                             vcpu->kvm->arch.crypto.crycb->dea_wrapping_key_mask;
 342         /* as 56%8 == 0, bitmap_xor won't overwrite any data */
 343         bitmap_xor(b1, b1, b2, BITS_PER_BYTE * 56);
 344 end:
 345         switch (ret) {
 346         case -EINVAL:
 347                 return set_validity_icpt(scb_s, 0x0022U);
 348         case -EFAULT:
 349                 return set_validity_icpt(scb_s, 0x0035U);
 350         case -EACCES:
 351                 return set_validity_icpt(scb_s, 0x003CU);
 352         }
 353         scb_s->crycbd = ((__u32)(__u64) &vsie_page->crycb) | CRYCB_FORMAT2;
 354         return 0;
 355 }
 356
 357 /* shadow (round up/down) the ibc to avoid validity icpt */
 358 static void prepare_ibc(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
 359 {
 360         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
 361         struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
 362         /* READ_ONCE does not work on bitfields - use a temporary variable */
 363         const uint32_t __new_ibc = scb_o->ibc;
 364         const uint32_t new_ibc = READ_ONCE(__new_ibc) & 0x0fffU;
 365         __u64 min_ibc = (sclp.ibc >> 16) & 0x0fffU;
 366
 367         scb_s->ibc = 0;
 368         /* ibc installed in g2 and requested for g3 */
 369         if (vcpu->kvm->arch.model.ibc && new_ibc) {
 370                 scb_s->ibc = new_ibc;
 371                 /* takte care of the minimum ibc level of the machine */
 372                 if (scb_s->ibc < min_ibc)
 373                         scb_s->ibc = min_ibc;
 374                 /* take care of the maximum ibc level set for the guest */
 375                 if (scb_s->ibc > vcpu->kvm->arch.model.ibc)
 376                         scb_s->ibc = vcpu->kvm->arch.model.ibc;
 377         }
 378 }
 379
 380 /* unshadow the scb, copying parameters back to the real scb */
 381 static void unshadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
 382 {
 383         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
 384         struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
 385
 386         /* interception */
 387         scb_o->icptcode = scb_s->icptcode;
 388         scb_o->icptstatus = scb_s->icptstatus;
 389         scb_o->ipa = scb_s->ipa;
 390         scb_o->ipb = scb_s->ipb;
 391         scb_o->gbea = scb_s->gbea;
 392
 393         /* timer */
 394         scb_o->cputm = scb_s->cputm;
 395         scb_o->ckc = scb_s->ckc;
 396         scb_o->todpr = scb_s->todpr;
 397
 398         /* guest state */
 399         scb_o->gpsw = scb_s->gpsw;
 400         scb_o->gg14 = scb_s->gg14;
 401         scb_o->gg15 = scb_s->gg15;
 402         memcpy(scb_o->gcr, scb_s->gcr, 128);
 403         scb_o->pp = scb_s->pp;
 404
 405         /* branch prediction */
 406         if (test_kvm_facility(vcpu->kvm, 82)) {
 407                 scb_o->fpf &= ~FPF_BPBC;
 408                 scb_o->fpf |= scb_s->fpf & FPF_BPBC;
 409         }
 410
 411         /* interrupt intercept */
 412         switch (scb_s->icptcode) {
 413         case ICPT_PROGI:
 414         case ICPT_INSTPROGI:
 415         case ICPT_EXTINT:
 416                 memcpy((void *)((u64)scb_o + 0xc0),
 417                        (void *)((u64)scb_s + 0xc0), 0xf0 - 0xc0);
 418                 break;
 419         case ICPT_PARTEXEC:
 420                 /* MVPG only */
 421                 memcpy((void *)((u64)scb_o + 0xc0),
 422                        (void *)((u64)scb_s + 0xc0), 0xd0 - 0xc0);
 423                 break;
 424         }
 425
 426         if (scb_s->ihcpu != 0xffffU)
 427                 scb_o->ihcpu = scb_s->ihcpu;
 428 }
 429
 430 /*
 431  * Setup the shadow scb by copying and checking the relevant parts of the g2
 432  * provided scb.
 433  *
 434  * Returns: - 0 if the scb has been shadowed
 435  *          - > 0 if control has to be given to guest 2
 436  */
 437 static int shadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
 438 {
 439         struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
 440         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
 441         /* READ_ONCE does not work on bitfields - use a temporary variable */
 442         const uint32_t __new_prefix = scb_o->prefix;
 443         const uint32_t new_prefix = READ_ONCE(__new_prefix);
 444         const bool wants_tx = READ_ONCE(scb_o->ecb) & ECB_TE;
 445         bool had_tx = scb_s->ecb & ECB_TE;
 446         unsigned long new_mso = 0;
 447         int rc;
 448
 449         /* make sure we don't have any leftovers when reusing the scb */
 450         scb_s->icptcode = 0;
 451         scb_s->eca = 0;
 452         scb_s->ecb = 0;
 453         scb_s->ecb2 = 0;
 454         scb_s->ecb3 = 0;
 455         scb_s->ecd = 0;
 456         scb_s->fac = 0;
 457         scb_s->fpf = 0;
 458
 459         rc = prepare_cpuflags(vcpu, vsie_page);
 460         if (rc)
 461                 goto out;
 462
 463         /* timer */
 464         scb_s->cputm = scb_o->cputm;
 465         scb_s->ckc = scb_o->ckc;
 466         scb_s->todpr = scb_o->todpr;
 467         scb_s->epoch = scb_o->epoch;
 468
 469         /* guest state */
 470         scb_s->gpsw = scb_o->gpsw;
 471         scb_s->gg14 = scb_o->gg14;
 472         scb_s->gg15 = scb_o->gg15;
 473         memcpy(scb_s->gcr, scb_o->gcr, 128);
 474         scb_s->pp = scb_o->pp;
 475
 476         /* interception / execution handling */
 477         scb_s->gbea = scb_o->gbea;
 478         scb_s->lctl = scb_o->lctl;
 479         scb_s->svcc = scb_o->svcc;
 480         scb_s->ictl = scb_o->ictl;
 481         /*
 482          * SKEY handling functions can't deal with false setting of PTE invalid
 483          * bits. Therefore we cannot provide interpretation and would later
 484          * have to provide own emulation handlers.
 485          */
 486         if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_KSS))
 487                 scb_s->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE;
 488
 489         scb_s->icpua = scb_o->icpua;
 490
 491         if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_SM))
 492                 new_mso = READ_ONCE(scb_o->mso) & 0xfffffffffff00000UL;
 493         /* if the hva of the prefix changes, we have to remap the prefix */
 494         if (scb_s->mso != new_mso || scb_s->prefix != new_prefix)
 495                 prefix_unmapped(vsie_page);
 496          /* SIE will do mso/msl validity and exception checks for us */
 497         scb_s->msl = scb_o->msl & 0xfffffffffff00000UL;
 498         scb_s->mso = new_mso;
 499         scb_s->prefix = new_prefix;
 500
 501         /* We have to definetly flush the tlb if this scb never ran */
 502         if (scb_s->ihcpu != 0xffffU)
 503                 scb_s->ihcpu = scb_o->ihcpu;
 504
 505         /* MVPG and Protection Exception Interpretation are always available */
 506         scb_s->eca |= scb_o->eca & (ECA_MVPGI | ECA_PROTEXCI);
 507         /* Host-protection-interruption introduced with ESOP */
 508         if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_ESOP))
 509                 scb_s->ecb |= scb_o->ecb & ECB_HOSTPROTINT;
 510         /* transactional execution */
 511         if (test_kvm_facility(vcpu->kvm, 73) && wants_tx) {
 512                 /* remap the prefix is tx is toggled on */
 513                 if (!had_tx)
 514                         prefix_unmapped(vsie_page);
 515                 scb_s->ecb |= ECB_TE;
 516         }
 517         /* branch prediction */
 518         if (test_kvm_facility(vcpu->kvm, 82))
 519                 scb_s->fpf |= scb_o->fpf & FPF_BPBC;
 520         /* SIMD */
 521         if (test_kvm_facility(vcpu->kvm, 129)) {
 522                 scb_s->eca |= scb_o->eca & ECA_VX;
 523                 scb_s->ecd |= scb_o->ecd & ECD_HOSTREGMGMT;
 524         }
 525         /* Run-time-Instrumentation */
 526         if (test_kvm_facility(vcpu->kvm, 64))
 527                 scb_s->ecb3 |= scb_o->ecb3 & ECB3_RI;
 528         /* Instruction Execution Prevention */
 529         if (test_kvm_facility(vcpu->kvm, 130))
 530                 scb_s->ecb2 |= scb_o->ecb2 & ECB2_IEP;
 531         /* Guarded Storage */
 532         if (test_kvm_facility(vcpu->kvm, 133)) {
 533                 scb_s->ecb |= scb_o->ecb & ECB_GS;
 534                 scb_s->ecd |= scb_o->ecd & ECD_HOSTREGMGMT;
 535         }
 536         if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_SIIF))
 537                 scb_s->eca |= scb_o->eca & ECA_SII;
 538         if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_IB))
 539                 scb_s->eca |= scb_o->eca & ECA_IB;
 540         if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_CEI))
 541                 scb_s->eca |= scb_o->eca & ECA_CEI;
 542         /* Epoch Extension */
 543         if (test_kvm_facility(vcpu->kvm, 139))
 544                 scb_s->ecd |= scb_o->ecd & ECD_MEF;
 545
 546         /* etoken */
 547         if (test_kvm_facility(vcpu->kvm, 156))
 548                 scb_s->ecd |= scb_o->ecd & ECD_ETOKENF;
 549
 550         scb_s->hpid = HPID_VSIE;
 551         scb_s->cpnc = scb_o->cpnc;
 552
 553         prepare_ibc(vcpu, vsie_page);
 554         rc = shadow_crycb(vcpu, vsie_page);
 555 out:
 556         if (rc)
 557                 unshadow_scb(vcpu, vsie_page);
 558         return rc;
 559 }
 560
 561 void kvm_s390_vsie_gmap_notifier(struct gmap *gmap, unsigned long start,
 562                                  unsigned long end)
 563 {
 564         struct kvm *kvm = gmap->private;
 565         struct vsie_page *cur;
 566         unsigned long prefix;
 567         struct page *page;
 568         int i;
 569
 570         if (!gmap_is_shadow(gmap))
 571                 return;
 572         if (start >= 1UL << 31)
 573                 /* We are only interested in prefix pages */
 574                 return;
 575
 576         /*
 577          * Only new shadow blocks are added to the list during runtime,
 578          * therefore we can safely reference them all the time.
 579          */
 580         for (i = 0; i < kvm->arch.vsie.page_count; i++) {
 581                 page = READ_ONCE(kvm->arch.vsie.pages[i]);
 582                 if (!page)
 583                         continue;
 584                 cur = page_to_virt(page);
 585                 if (READ_ONCE(cur->gmap) != gmap)
 586                         continue;
 587                 prefix = cur->scb_s.prefix << GUEST_PREFIX_SHIFT;
 588                 /* with mso/msl, the prefix lies at an offset */
 589                 prefix += cur->scb_s.mso;
 590                 if (prefix <= end && start <= prefix + 2 * PAGE_SIZE - 1)
 591                         prefix_unmapped_sync(cur);
 592         }
 593 }
 594
 595 /*
 596  * Map the first prefix page and if tx is enabled also the second prefix page.
 597  *
 598  * The prefix will be protected, a gmap notifier will inform about unmaps.
 599  * The shadow scb must not be executed until the prefix is remapped, this is
 600  * guaranteed by properly handling PROG_REQUEST.
 601  *
 602  * Returns: - 0 on if successfully mapped or already mapped
 603  *          - > 0 if control has to be given to guest 2
 604  *          - -EAGAIN if the caller can retry immediately
 605  *          - -ENOMEM if out of memory
 606  */
 607 static int map_prefix(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
 608 {
 609         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
 610         u64 prefix = scb_s->prefix << GUEST_PREFIX_SHIFT;
 611         int rc;
 612
 613         if (prefix_is_mapped(vsie_page))
 614                 return 0;
 615
 616         /* mark it as mapped so we can catch any concurrent unmappers */
 617         prefix_mapped(vsie_page);
 618
 619         /* with mso/msl, the prefix lies at offset *mso* */
 620         prefix += scb_s->mso;
 621
 622         rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, prefix);
 623         if (!rc && (scb_s->ecb & ECB_TE))
 624                 rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap,
 625                                            prefix + PAGE_SIZE);
 626         /*
 627          * We don't have to mprotect, we will be called for all unshadows.
 628          * SIE will detect if protection applies and trigger a validity.
 629          */
 630         if (rc)
 631                 prefix_unmapped(vsie_page);
 632         if (rc > 0 || rc == -EFAULT)
 633                 rc = set_validity_icpt(scb_s, 0x0037U);
 634         return rc;
 635 }
 636
 637 /*
 638  * Pin the guest page given by gpa and set hpa to the pinned host address.
 639  * Will always be pinned writable.
 640  *
 641  * Returns: - 0 on success
 642  *          - -EINVAL if the gpa is not valid guest storage
 643  */
 644 static int pin_guest_page(struct kvm *kvm, gpa_t gpa, hpa_t *hpa)
 645 {
 646         struct page *page;
 647
 648         page = gfn_to_page(kvm, gpa_to_gfn(gpa));
 649         if (is_error_page(page))
 650                 return -EINVAL;
 651         *hpa = (hpa_t) page_to_virt(page) + (gpa & ~PAGE_MASK);
 652         return 0;
 653 }
 654
 655 /* Unpins a page previously pinned via pin_guest_page, marking it as dirty. */
 656 static void unpin_guest_page(struct kvm *kvm, gpa_t gpa, hpa_t hpa)
 657 {
 658         kvm_release_pfn_dirty(hpa >> PAGE_SHIFT);
 659         /* mark the page always as dirty for migration */
 660         mark_page_dirty(kvm, gpa_to_gfn(gpa));
 661 }
 662
 663 /* unpin all blocks previously pinned by pin_blocks(), marking them dirty */
 664 static void unpin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
 665 {
 666         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
 667         hpa_t hpa;
 668
 669         hpa = (u64) scb_s->scaoh << 32 | scb_s->scaol;
 670         if (hpa) {
 671                 unpin_guest_page(vcpu->kvm, vsie_page->sca_gpa, hpa);
 672                 vsie_page->sca_gpa = 0;
 673                 scb_s->scaol = 0;
 674                 scb_s->scaoh = 0;
 675         }
 676
 677         hpa = scb_s->itdba;
 678         if (hpa) {
 679                 unpin_guest_page(vcpu->kvm, vsie_page->itdba_gpa, hpa);
 680                 vsie_page->itdba_gpa = 0;
 681                 scb_s->itdba = 0;
 682         }
 683
 684         hpa = scb_s->gvrd;
 685         if (hpa) {
 686                 unpin_guest_page(vcpu->kvm, vsie_page->gvrd_gpa, hpa);
 687                 vsie_page->gvrd_gpa = 0;
 688                 scb_s->gvrd = 0;
 689         }
 690
 691         hpa = scb_s->riccbd;
 692         if (hpa) {
 693                 unpin_guest_page(vcpu->kvm, vsie_page->riccbd_gpa, hpa);
 694                 vsie_page->riccbd_gpa = 0;
 695                 scb_s->riccbd = 0;
 696         }
 697
 698         hpa = scb_s->sdnxo;
 699         if (hpa) {
 700                 unpin_guest_page(vcpu->kvm, vsie_page->sdnx_gpa, hpa);
 701                 vsie_page->sdnx_gpa = 0;
 702                 scb_s->sdnxo = 0;
 703         }
 704 }
 705
 706 /*
 707  * Instead of shadowing some blocks, we can simply forward them because the
 708  * addresses in the scb are 64 bit long.
 709  *
 710  * This works as long as the data lies in one page. If blocks ever exceed one
 711  * page, we have to fall back to shadowing.
 712  *
 713  * As we reuse the sca, the vcpu pointers contained in it are invalid. We must
 714  * therefore not enable any facilities that access these pointers (e.g. SIGPIF).
 715  *
 716  * Returns: - 0 if all blocks were pinned.
 717  *          - > 0 if control has to be given to guest 2
 718  *          - -ENOMEM if out of memory
 719  */
 720 static int pin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
 721 {
 722         struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
 723         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
 724         hpa_t hpa;
 725         gpa_t gpa;
 726         int rc = 0;
 727
 728         gpa = READ_ONCE(scb_o->scaol) & ~0xfUL;
 729         if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_64BSCAO))
 730                 gpa |= (u64) READ_ONCE(scb_o->scaoh) << 32;
 731         if (gpa) {
 732                 if (gpa < 2 * PAGE_SIZE)
 733                         rc = set_validity_icpt(scb_s, 0x0038U);
 734                 else if ((gpa & ~0x1fffUL) == kvm_s390_get_prefix(vcpu))
 735                         rc = set_validity_icpt(scb_s, 0x0011U);
 736                 else if ((gpa & PAGE_MASK) !=
 737                          ((gpa + sizeof(struct bsca_block) - 1) & PAGE_MASK))
 738                         rc = set_validity_icpt(scb_s, 0x003bU);
 739                 if (!rc) {
 740                         rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
 741                         if (rc)
 742                                 rc = set_validity_icpt(scb_s, 0x0034U);
 743                 }
 744                 if (rc)
 745                         goto unpin;
 746                 vsie_page->sca_gpa = gpa;
 747                 scb_s->scaoh = (u32)((u64)hpa >> 32);
 748                 scb_s->scaol = (u32)(u64)hpa;
 749         }
 750
 751         gpa = READ_ONCE(scb_o->itdba) & ~0xffUL;
 752         if (gpa && (scb_s->ecb & ECB_TE)) {
 753                 if (gpa < 2 * PAGE_SIZE) {
 754                         rc = set_validity_icpt(scb_s, 0x0080U);
 755                         goto unpin;
 756                 }
 757                 /* 256 bytes cannot cross page boundaries */
 758                 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
 759                 if (rc) {
 760                         rc = set_validity_icpt(scb_s, 0x0080U);
 761                         goto unpin;
 762                 }
 763                 vsie_page->itdba_gpa = gpa;
 764                 scb_s->itdba = hpa;
 765         }
 766
 767         gpa = READ_ONCE(scb_o->gvrd) & ~0x1ffUL;
 768         if (gpa && (scb_s->eca & ECA_VX) && !(scb_s->ecd & ECD_HOSTREGMGMT)) {
 769                 if (gpa < 2 * PAGE_SIZE) {
 770                         rc = set_validity_icpt(scb_s, 0x1310U);
 771                         goto unpin;
 772                 }
 773                 /*
 774                  * 512 bytes vector registers cannot cross page boundaries
 775                  * if this block gets bigger, we have to shadow it.
 776                  */
 777                 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
 778                 if (rc) {
 779                         rc = set_validity_icpt(scb_s, 0x1310U);
 780                         goto unpin;
 781                 }
 782                 vsie_page->gvrd_gpa = gpa;
 783                 scb_s->gvrd = hpa;
 784         }
 785
 786         gpa = READ_ONCE(scb_o->riccbd) & ~0x3fUL;
 787         if (gpa && (scb_s->ecb3 & ECB3_RI)) {
 788                 if (gpa < 2 * PAGE_SIZE) {
 789                         rc = set_validity_icpt(scb_s, 0x0043U);
 790                         goto unpin;
 791                 }
 792                 /* 64 bytes cannot cross page boundaries */
 793                 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
 794                 if (rc) {
 795                         rc = set_validity_icpt(scb_s, 0x0043U);
 796                         goto unpin;
 797                 }
 798                 /* Validity 0x0044 will be checked by SIE */
 799                 vsie_page->riccbd_gpa = gpa;
 800                 scb_s->riccbd = hpa;
 801         }
 802         if (((scb_s->ecb & ECB_GS) && !(scb_s->ecd & ECD_HOSTREGMGMT)) ||
 803             (scb_s->ecd & ECD_ETOKENF)) {
 804                 unsigned long sdnxc;
 805
 806                 gpa = READ_ONCE(scb_o->sdnxo) & ~0xfUL;
 807                 sdnxc = READ_ONCE(scb_o->sdnxo) & 0xfUL;
 808                 if (!gpa || gpa < 2 * PAGE_SIZE) {
 809                         rc = set_validity_icpt(scb_s, 0x10b0U);
 810                         goto unpin;
 811                 }
 812                 if (sdnxc < 6 || sdnxc > 12) {
 813                         rc = set_validity_icpt(scb_s, 0x10b1U);
 814                         goto unpin;
 815                 }
 816                 if (gpa & ((1 << sdnxc) - 1)) {
 817                         rc = set_validity_icpt(scb_s, 0x10b2U);
 818                         goto unpin;
 819                 }
 820                 /* Due to alignment rules (checked above) this cannot
 821                  * cross page boundaries
 822                  */
 823                 rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
 824                 if (rc) {
 825                         rc = set_validity_icpt(scb_s, 0x10b0U);
 826                         goto unpin;
 827                 }
 828                 vsie_page->sdnx_gpa = gpa;
 829                 scb_s->sdnxo = hpa | sdnxc;
 830         }
 831         return 0;
 832 unpin:
 833         unpin_blocks(vcpu, vsie_page);
 834         return rc;
 835 }
 836
 837 /* unpin the scb provided by guest 2, marking it as dirty */
 838 static void unpin_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page,
 839                       gpa_t gpa)
 840 {
 841         hpa_t hpa = (hpa_t) vsie_page->scb_o;
 842
 843         if (hpa)
 844                 unpin_guest_page(vcpu->kvm, gpa, hpa);
 845         vsie_page->scb_o = NULL;
 846 }
 847
 848 /*
 849  * Pin the scb at gpa provided by guest 2 at vsie_page->scb_o.
 850  *
 851  * Returns: - 0 if the scb was pinned.
 852  *          - > 0 if control has to be given to guest 2
 853  */
 854 static int pin_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page,
 855                    gpa_t gpa)
 856 {
 857         hpa_t hpa;
 858         int rc;
 859
 860         rc = pin_guest_page(vcpu->kvm, gpa, &hpa);
 861         if (rc) {
 862                 rc = kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
 863                 WARN_ON_ONCE(rc);
 864                 return 1;
 865         }
 866         vsie_page->scb_o = (struct kvm_s390_sie_block *) hpa;
 867         return 0;
 868 }
 869
 870 /*
 871  * Inject a fault into guest 2.
 872  *
 873  * Returns: - > 0 if control has to be given to guest 2
 874  *            < 0 if an error occurred during injection.
 875  */
 876 static int inject_fault(struct kvm_vcpu *vcpu, __u16 code, __u64 vaddr,
 877                         bool write_flag)
 878 {
 879         struct kvm_s390_pgm_info pgm = {
 880                 .code = code,
 881                 .trans_exc_code =
 882                         /* 0-51: virtual address */
 883                         (vaddr & 0xfffffffffffff000UL) |
 884                         /* 52-53: store / fetch */
 885                         (((unsigned int) !write_flag) + 1) << 10,
 886                         /* 62-63: asce id (alway primary == 0) */
 887                 .exc_access_id = 0, /* always primary */
 888                 .op_access_id = 0, /* not MVPG */
 889         };
 890         int rc;
 891
 892         if (code == PGM_PROTECTION)
 893                 pgm.trans_exc_code |= 0x4UL;
 894
 895         rc = kvm_s390_inject_prog_irq(vcpu, &pgm);
 896         return rc ? rc : 1;
 897 }
 898
 899 /*
 900  * Handle a fault during vsie execution on a gmap shadow.
 901  *
 902  * Returns: - 0 if the fault was resolved
 903  *          - > 0 if control has to be given to guest 2
 904  *          - < 0 if an error occurred
 905  */
 906 static int handle_fault(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
 907 {
 908         int rc;
 909
 910         if (current->thread.gmap_int_code == PGM_PROTECTION)
 911                 /* we can directly forward all protection exceptions */
 912                 return inject_fault(vcpu, PGM_PROTECTION,
 913                                     current->thread.gmap_addr, 1);
 914
 915         rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap,
 916                                    current->thread.gmap_addr);
 917         if (rc > 0) {
 918                 rc = inject_fault(vcpu, rc,
 919                                   current->thread.gmap_addr,
 920                                   current->thread.gmap_write_flag);
 921                 if (rc >= 0)
 922                         vsie_page->fault_addr = current->thread.gmap_addr;
 923         }
 924         return rc;
 925 }
 926
 927 /*
 928  * Retry the previous fault that required guest 2 intervention. This avoids
 929  * one superfluous SIE re-entry and direct exit.
 930  *
 931  * Will ignore any errors. The next SIE fault will do proper fault handling.
 932  */
 933 static void handle_last_fault(struct kvm_vcpu *vcpu,
 934                               struct vsie_page *vsie_page)
 935 {
 936         if (vsie_page->fault_addr)
 937                 kvm_s390_shadow_fault(vcpu, vsie_page->gmap,
 938                                       vsie_page->fault_addr);
 939         vsie_page->fault_addr = 0;
 940 }
 941
 942 static inline void clear_vsie_icpt(struct vsie_page *vsie_page)
 943 {
 944         vsie_page->scb_s.icptcode = 0;
 945 }
 946
 947 /* rewind the psw and clear the vsie icpt, so we can retry execution */
 948 static void retry_vsie_icpt(struct vsie_page *vsie_page)
 949 {
 950         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
 951         int ilen = insn_length(scb_s->ipa >> 8);
 952
 953         /* take care of EXECUTE instructions */
 954         if (scb_s->icptstatus & 1) {
 955                 ilen = (scb_s->icptstatus >> 4) & 0x6;
 956                 if (!ilen)
 957                         ilen = 4;
 958         }
 959         scb_s->gpsw.addr = __rewind_psw(scb_s->gpsw, ilen);
 960         clear_vsie_icpt(vsie_page);
 961 }
 962
 963 /*
 964  * Try to shadow + enable the guest 2 provided facility list.
 965  * Retry instruction execution if enabled for and provided by guest 2.
 966  *
 967  * Returns: - 0 if handled (retry or guest 2 icpt)
 968  *          - > 0 if control has to be given to guest 2
 969  */
 970 static int handle_stfle(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
 971 {
 972         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
 973         __u32 fac = READ_ONCE(vsie_page->scb_o->fac) & 0x7ffffff8U;
 974
 975         if (fac && test_kvm_facility(vcpu->kvm, 7)) {
 976                 retry_vsie_icpt(vsie_page);
 977                 if (read_guest_real(vcpu, fac, &vsie_page->fac,
 978                                     sizeof(vsie_page->fac)))
 979                         return set_validity_icpt(scb_s, 0x1090U);
 980                 scb_s->fac = (__u32)(__u64) &vsie_page->fac;
 981         }
 982         return 0;
 983 }
 984
 985 /*
 986  * Run the vsie on a shadow scb and a shadow gmap, without any further
 987  * sanity checks, handling SIE faults.
 988  *
 989  * Returns: - 0 everything went fine
 990  *          - > 0 if control has to be given to guest 2
 991  *          - < 0 if an error occurred
 992  */
 993 static int do_vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
 994         __releases(vcpu->kvm->srcu)
 995         __acquires(vcpu->kvm->srcu)
 996 {
 997         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
 998         struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
 999         int guest_bp_isolation;
1000         int rc = 0;
1001
1002         handle_last_fault(vcpu, vsie_page);
1003
1004         srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
1005
1006         /* save current guest state of bp isolation override */
1007         guest_bp_isolation = test_thread_flag(TIF_ISOLATE_BP_GUEST);
1008
1009         /*
1010          * The guest is running with BPBC, so we have to force it on for our
1011          * nested guest. This is done by enabling BPBC globally, so the BPBC
1012          * control in the SCB (which the nested guest can modify) is simply
1013          * ignored.
1014          */
1015         if (test_kvm_facility(vcpu->kvm, 82) &&
1016             vcpu->arch.sie_block->fpf & FPF_BPBC)
1017                 set_thread_flag(TIF_ISOLATE_BP_GUEST);
1018
1019         local_irq_disable();
1020         guest_enter_irqoff();
1021         local_irq_enable();
1022
1023         /*
1024          * Simulate a SIE entry of the VCPU (see sie64a), so VCPU blocking
1025          * and VCPU requests also hinder the vSIE from running and lead
1026          * to an immediate exit. kvm_s390_vsie_kick() has to be used to
1027          * also kick the vSIE.
1028          */
1029         vcpu->arch.sie_block->prog0c |= PROG_IN_SIE;
1030         barrier();
1031         if (!kvm_s390_vcpu_sie_inhibited(vcpu))
1032                 rc = sie64a(scb_s, vcpu->run->s.regs.gprs);
1033         barrier();
1034         vcpu->arch.sie_block->prog0c &= ~PROG_IN_SIE;
1035
1036         local_irq_disable();
1037         guest_exit_irqoff();
1038         local_irq_enable();
1039
1040         /* restore guest state for bp isolation override */
1041         if (!guest_bp_isolation)
1042                 clear_thread_flag(TIF_ISOLATE_BP_GUEST);
1043
1044         vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
1045
1046         if (rc == -EINTR) {
1047                 VCPU_EVENT(vcpu, 3, "%s", "machine check");
1048                 kvm_s390_reinject_machine_check(vcpu, &vsie_page->mcck_info);
1049                 return 0;
1050         }
1051
1052         if (rc > 0)
1053                 rc = 0; /* we could still have an icpt */
1054         else if (rc == -EFAULT)
1055                 return handle_fault(vcpu, vsie_page);
1056
1057         switch (scb_s->icptcode) {
1058         case ICPT_INST:
1059                 if (scb_s->ipa == 0xb2b0)
1060                         rc = handle_stfle(vcpu, vsie_page);
1061                 break;
1062         case ICPT_STOP:
1063                 /* stop not requested by g2 - must have been a kick */
1064                 if (!(atomic_read(&scb_o->cpuflags) & CPUSTAT_STOP_INT))
1065                         clear_vsie_icpt(vsie_page);
1066                 break;
1067         case ICPT_VALIDITY:
1068                 if ((scb_s->ipa & 0xf000) != 0xf000)
1069                         scb_s->ipa += 0x1000;
1070                 break;
1071         }
1072         return rc;
1073 }
1074
1075 static void release_gmap_shadow(struct vsie_page *vsie_page)
1076 {
1077         if (vsie_page->gmap)
1078                 gmap_put(vsie_page->gmap);
1079         WRITE_ONCE(vsie_page->gmap, NULL);
1080         prefix_unmapped(vsie_page);
1081 }
1082
1083 static int acquire_gmap_shadow(struct kvm_vcpu *vcpu,
1084                                struct vsie_page *vsie_page)
1085 {
1086         unsigned long asce;
1087         union ctlreg0 cr0;
1088         struct gmap *gmap;
1089         int edat;
1090
1091         asce = vcpu->arch.sie_block->gcr[1];
1092         cr0.val = vcpu->arch.sie_block->gcr[0];
1093         edat = cr0.edat && test_kvm_facility(vcpu->kvm, 8);
1094         edat += edat && test_kvm_facility(vcpu->kvm, 78);
1095
1096         /*
1097          * ASCE or EDAT could have changed since last icpt, or the gmap
1098          * we're holding has been unshadowed. If the gmap is still valid,
1099          * we can safely reuse it.
1100          */
1101         if (vsie_page->gmap && gmap_shadow_valid(vsie_page->gmap, asce, edat))
1102                 return 0;
1103
1104         /* release the old shadow - if any, and mark the prefix as unmapped */
1105         release_gmap_shadow(vsie_page);
1106         gmap = gmap_shadow(vcpu->arch.gmap, asce, edat);
1107         if (IS_ERR(gmap))
1108                 return PTR_ERR(gmap);
1109         gmap->private = vcpu->kvm;
1110         WRITE_ONCE(vsie_page->gmap, gmap);
1111         return 0;
1112 }
1113
1114 /*
1115  * Register the shadow scb at the VCPU, e.g. for kicking out of vsie.
1116  */
1117 static void register_shadow_scb(struct kvm_vcpu *vcpu,
1118                                 struct vsie_page *vsie_page)
1119 {
1120         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
1121
1122         WRITE_ONCE(vcpu->arch.vsie_block, &vsie_page->scb_s);
1123         /*
1124          * External calls have to lead to a kick of the vcpu and
1125          * therefore the vsie -> Simulate Wait state.
1126          */
1127         kvm_s390_set_cpuflags(vcpu, CPUSTAT_WAIT);
1128         /*
1129          * We have to adjust the g3 epoch by the g2 epoch. The epoch will
1130          * automatically be adjusted on tod clock changes via kvm_sync_clock.
1131          */
1132         preempt_disable();
1133         scb_s->epoch += vcpu->kvm->arch.epoch;
1134
1135         if (scb_s->ecd & ECD_MEF) {
1136                 scb_s->epdx += vcpu->kvm->arch.epdx;
1137                 if (scb_s->epoch < vcpu->kvm->arch.epoch)
1138                         scb_s->epdx += 1;
1139         }
1140
1141         preempt_enable();
1142 }
1143
1144 /*
1145  * Unregister a shadow scb from a VCPU.
1146  */
1147 static void unregister_shadow_scb(struct kvm_vcpu *vcpu)
1148 {
1149         kvm_s390_clear_cpuflags(vcpu, CPUSTAT_WAIT);
1150         WRITE_ONCE(vcpu->arch.vsie_block, NULL);
1151 }
1152
1153 /*
1154  * Run the vsie on a shadowed scb, managing the gmap shadow, handling
1155  * prefix pages and faults.
1156  *
1157  * Returns: - 0 if no errors occurred
1158  *          - > 0 if control has to be given to guest 2
1159  *          - -ENOMEM if out of memory
1160  */
1161 static int vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
1162 {
1163         struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
1164         int rc = 0;
1165
1166         while (1) {
1167                 rc = acquire_gmap_shadow(vcpu, vsie_page);
1168                 if (!rc)
1169                         rc = map_prefix(vcpu, vsie_page);
1170                 if (!rc) {
1171                         gmap_enable(vsie_page->gmap);
1172                         update_intervention_requests(vsie_page);
1173                         rc = do_vsie_run(vcpu, vsie_page);
1174                         gmap_enable(vcpu->arch.gmap);
1175                 }
1176                 atomic_andnot(PROG_BLOCK_SIE, &scb_s->prog20);
1177
1178                 if (rc == -EAGAIN)
1179                         rc = 0;
1180                 if (rc || scb_s->icptcode || signal_pending(current) ||
1181                     kvm_s390_vcpu_has_irq(vcpu, 0) ||
1182                     kvm_s390_vcpu_sie_inhibited(vcpu))
1183                         break;
1184                 cond_resched();
1185         }
1186
1187         if (rc == -EFAULT) {
1188                 /*
1189                  * Addressing exceptions are always presentes as intercepts.
1190                  * As addressing exceptions are suppressing and our guest 3 PSW
1191                  * points at the responsible instruction, we have to
1192                  * forward the PSW and set the ilc. If we can't read guest 3
1193                  * instruction, we can use an arbitrary ilc. Let's always use
1194                  * ilen = 4 for now, so we can avoid reading in guest 3 virtual
1195                  * memory. (we could also fake the shadow so the hardware
1196                  * handles it).
1197                  */
1198                 scb_s->icptcode = ICPT_PROGI;
1199                 scb_s->iprcc = PGM_ADDRESSING;
1200                 scb_s->pgmilc = 4;
1201                 scb_s->gpsw.addr = __rewind_psw(scb_s->gpsw, 4);
1202                 rc = 1;
1203         }
1204         return rc;
1205 }
1206
1207 /*
1208  * Get or create a vsie page for a scb address.
1209  *
1210  * Returns: - address of a vsie page (cached or new one)
1211  *          - NULL if the same scb address is already used by another VCPU
1212  *          - ERR_PTR(-ENOMEM) if out of memory
1213  */
1214 static struct vsie_page *get_vsie_page(struct kvm *kvm, unsigned long addr)
1215 {
1216         struct vsie_page *vsie_page;
1217         struct page *page;
1218         int nr_vcpus;
1219
1220         rcu_read_lock();
1221         page = radix_tree_lookup(&kvm->arch.vsie.addr_to_page, addr >> 9);
1222         rcu_read_unlock();
1223         if (page) {
1224                 if (page_ref_inc_return(page) == 2)
1225                         return page_to_virt(page);
1226                 page_ref_dec(page);
1227         }
1228
1229         /*
1230          * We want at least #online_vcpus shadows, so every VCPU can execute
1231          * the VSIE in parallel.
1232          */
1233         nr_vcpus = atomic_read(&kvm->online_vcpus);
1234
1235         mutex_lock(&kvm->arch.vsie.mutex);
1236         if (kvm->arch.vsie.page_count < nr_vcpus) {
1237                 page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO | GFP_DMA);
1238                 if (!page) {
1239                         mutex_unlock(&kvm->arch.vsie.mutex);
1240                         return ERR_PTR(-ENOMEM);
1241                 }
1242                 page_ref_inc(page);
1243                 kvm->arch.vsie.pages[kvm->arch.vsie.page_count] = page;
1244                 kvm->arch.vsie.page_count++;
1245         } else {
1246                 /* reuse an existing entry that belongs to nobody */
1247                 while (true) {
1248                         page = kvm->arch.vsie.pages[kvm->arch.vsie.next];
1249                         if (page_ref_inc_return(page) == 2)
1250                                 break;
1251                         page_ref_dec(page);
1252                         kvm->arch.vsie.next++;
1253                         kvm->arch.vsie.next %= nr_vcpus;
1254                 }
1255                 radix_tree_delete(&kvm->arch.vsie.addr_to_page, page->index >> 9);
1256         }
1257         page->index = addr;
1258         /* double use of the same address */
1259         if (radix_tree_insert(&kvm->arch.vsie.addr_to_page, addr >> 9, page)) {
1260                 page_ref_dec(page);
1261                 mutex_unlock(&kvm->arch.vsie.mutex);
1262                 return NULL;
1263         }
1264         mutex_unlock(&kvm->arch.vsie.mutex);
1265
1266         vsie_page = page_to_virt(page);
1267         memset(&vsie_page->scb_s, 0, sizeof(struct kvm_s390_sie_block));
1268         release_gmap_shadow(vsie_page);
1269         vsie_page->fault_addr = 0;
1270         vsie_page->scb_s.ihcpu = 0xffffU;
1271         return vsie_page;
1272 }
1273
1274 /* put a vsie page acquired via get_vsie_page */
1275 static void put_vsie_page(struct kvm *kvm, struct vsie_page *vsie_page)
1276 {
1277         struct page *page = pfn_to_page(__pa(vsie_page) >> PAGE_SHIFT);
1278
1279         page_ref_dec(page);
1280 }
1281
1282 int kvm_s390_handle_vsie(struct kvm_vcpu *vcpu)
1283 {
1284         struct vsie_page *vsie_page;
1285         unsigned long scb_addr;
1286         int rc;
1287
1288         vcpu->stat.instruction_sie++;
1289         if (!test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_SIEF2))
1290                 return -EOPNOTSUPP;
1291         if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
1292                 return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
1293
1294         BUILD_BUG_ON(sizeof(struct vsie_page) != PAGE_SIZE);
1295         scb_addr = kvm_s390_get_base_disp_s(vcpu, NULL);
1296
1297         /* 512 byte alignment */
1298         if (unlikely(scb_addr & 0x1ffUL))
1299                 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
1300
1301         if (signal_pending(current) || kvm_s390_vcpu_has_irq(vcpu, 0) ||
1302             kvm_s390_vcpu_sie_inhibited(vcpu))
1303                 return 0;
1304
1305         vsie_page = get_vsie_page(vcpu->kvm, scb_addr);
1306         if (IS_ERR(vsie_page))
1307                 return PTR_ERR(vsie_page);
1308         else if (!vsie_page)
1309                 /* double use of sie control block - simply do nothing */
1310                 return 0;
1311
1312         rc = pin_scb(vcpu, vsie_page, scb_addr);
1313         if (rc)
1314                 goto out_put;
1315         rc = shadow_scb(vcpu, vsie_page);
1316         if (rc)
1317                 goto out_unpin_scb;
1318         rc = pin_blocks(vcpu, vsie_page);
1319         if (rc)
1320                 goto out_unshadow;
1321         register_shadow_scb(vcpu, vsie_page);
1322         rc = vsie_run(vcpu, vsie_page);
1323         unregister_shadow_scb(vcpu);
1324         unpin_blocks(vcpu, vsie_page);
1325 out_unshadow:
1326         unshadow_scb(vcpu, vsie_page);
1327 out_unpin_scb:
1328         unpin_scb(vcpu, vsie_page, scb_addr);
1329 out_put:
1330         put_vsie_page(vcpu->kvm, vsie_page);
1331
1332         return rc < 0 ? rc : 0;
1333 }
1334
1335 /* Init the vsie data structures. To be called when a vm is initialized. */
1336 void kvm_s390_vsie_init(struct kvm *kvm)
1337 {
1338         mutex_init(&kvm->arch.vsie.mutex);
1339         INIT_RADIX_TREE(&kvm->arch.vsie.addr_to_page, GFP_KERNEL_ACCOUNT);
1340 }
1341
1342 /* Destroy the vsie data structures. To be called when a vm is destroyed. */
1343 void kvm_s390_vsie_destroy(struct kvm *kvm)
1344 {
1345         struct vsie_page *vsie_page;
1346         struct page *page;
1347         int i;
1348
1349         mutex_lock(&kvm->arch.vsie.mutex);
1350         for (i = 0; i < kvm->arch.vsie.page_count; i++) {
1351                 page = kvm->arch.vsie.pages[i];
1352                 kvm->arch.vsie.pages[i] = NULL;
1353                 vsie_page = page_to_virt(page);
1354                 release_gmap_shadow(vsie_page);
1355                 /* free the radix tree entry */
1356                 radix_tree_delete(&kvm->arch.vsie.addr_to_page, page->index >> 9);
1357                 __free_page(page);
1358         }
1359         kvm->arch.vsie.page_count = 0;
1360         mutex_unlock(&kvm->arch.vsie.mutex);
1361 }
1362
1363 void kvm_s390_vsie_kick(struct kvm_vcpu *vcpu)
1364 {
1365         struct kvm_s390_sie_block *scb = READ_ONCE(vcpu->arch.vsie_block);
1366
1367         /*
1368          * Even if the VCPU lets go of the shadow sie block reference, it is
1369          * still valid in the cache. So we can safely kick it.
1370          */
1371         if (scb) {
1372                 atomic_or(PROG_BLOCK_SIE, &scb->prog20);
1373                 if (scb->prog0c & PROG_IN_SIE)
1374                         atomic_or(CPUSTAT_STOP_INT, &scb->cpuflags);
1375         }
1376 }