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