kernel/arch/s390/kvm/intercept.c

   1 /*
   2  * in-kernel handling for sie intercepts
   3  *
   4  * Copyright IBM Corp. 2008, 2014
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License (version 2 only)
   8  * as published by the Free Software Foundation.
   9  *
  10  *    Author(s): Carsten Otte <cotte@de.ibm.com>
  11  *               Christian Borntraeger <borntraeger@de.ibm.com>
  12  */
  13
  14 #include <linux/kvm_host.h>
  15 #include <linux/errno.h>
  16 #include <linux/pagemap.h>
  17
  18 #include <asm/kvm_host.h>
  19 #include <asm/asm-offsets.h>
  20 #include <asm/irq.h>
  21
  22 #include "kvm-s390.h"
  23 #include "gaccess.h"
  24 #include "trace.h"
  25 #include "trace-s390.h"
  26
  27
  28 static const intercept_handler_t instruction_handlers[256] = {
  29         [0x01] = kvm_s390_handle_01,
  30         [0x82] = kvm_s390_handle_lpsw,
  31         [0x83] = kvm_s390_handle_diag,
  32         [0xae] = kvm_s390_handle_sigp,
  33         [0xb2] = kvm_s390_handle_b2,
  34         [0xb6] = kvm_s390_handle_stctl,
  35         [0xb7] = kvm_s390_handle_lctl,
  36         [0xb9] = kvm_s390_handle_b9,
  37         [0xe5] = kvm_s390_handle_e5,
  38         [0xeb] = kvm_s390_handle_eb,
  39 };
  40
  41 void kvm_s390_rewind_psw(struct kvm_vcpu *vcpu, int ilc)
  42 {
  43         struct kvm_s390_sie_block *sie_block = vcpu->arch.sie_block;
  44
  45         /* Use the length of the EXECUTE instruction if necessary */
  46         if (sie_block->icptstatus & 1) {
  47                 ilc = (sie_block->icptstatus >> 4) & 0x6;
  48                 if (!ilc)
  49                         ilc = 4;
  50         }
  51         sie_block->gpsw.addr = __rewind_psw(sie_block->gpsw, ilc);
  52 }
  53
  54 static int handle_noop(struct kvm_vcpu *vcpu)
  55 {
  56         switch (vcpu->arch.sie_block->icptcode) {
  57         case 0x0:
  58                 vcpu->stat.exit_null++;
  59                 break;
  60         case 0x10:
  61                 vcpu->stat.exit_external_request++;
  62                 break;
  63         default:
  64                 break; /* nothing */
  65         }
  66         return 0;
  67 }
  68
  69 static int handle_stop(struct kvm_vcpu *vcpu)
  70 {
  71         struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;
  72         int rc = 0;
  73         uint8_t flags, stop_pending;
  74
  75         vcpu->stat.exit_stop_request++;
  76
  77         /* delay the stop if any non-stop irq is pending */
  78         if (kvm_s390_vcpu_has_irq(vcpu, 1))
  79                 return 0;
  80
  81         /* avoid races with the injection/SIGP STOP code */
  82         spin_lock(&li->lock);
  83         flags = li->irq.stop.flags;
  84         stop_pending = kvm_s390_is_stop_irq_pending(vcpu);
  85         spin_unlock(&li->lock);
  86
  87         trace_kvm_s390_stop_request(stop_pending, flags);
  88         if (!stop_pending)
  89                 return 0;
  90
  91         if (flags & KVM_S390_STOP_FLAG_STORE_STATUS) {
  92                 rc = kvm_s390_vcpu_store_status(vcpu,
  93                                                 KVM_S390_STORE_STATUS_NOADDR);
  94                 if (rc)
  95                         return rc;
  96         }
  97
  98         if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm))
  99                 kvm_s390_vcpu_stop(vcpu);
 100         return -EOPNOTSUPP;
 101 }
 102
 103 static int handle_validity(struct kvm_vcpu *vcpu)
 104 {
 105         int viwhy = vcpu->arch.sie_block->ipb >> 16;
 106
 107         vcpu->stat.exit_validity++;
 108         trace_kvm_s390_intercept_validity(vcpu, viwhy);
 109         WARN_ONCE(true, "kvm: unhandled validity intercept 0x%x\n", viwhy);
 110         return -EOPNOTSUPP;
 111 }
 112
 113 static int handle_instruction(struct kvm_vcpu *vcpu)
 114 {
 115         intercept_handler_t handler;
 116
 117         vcpu->stat.exit_instruction++;
 118         trace_kvm_s390_intercept_instruction(vcpu,
 119                                              vcpu->arch.sie_block->ipa,
 120                                              vcpu->arch.sie_block->ipb);
 121         handler = instruction_handlers[vcpu->arch.sie_block->ipa >> 8];
 122         if (handler)
 123                 return handler(vcpu);
 124         return -EOPNOTSUPP;
 125 }
 126
 127 static void __extract_prog_irq(struct kvm_vcpu *vcpu,
 128                                struct kvm_s390_pgm_info *pgm_info)
 129 {
 130         memset(pgm_info, 0, sizeof(struct kvm_s390_pgm_info));
 131         pgm_info->code = vcpu->arch.sie_block->iprcc;
 132
 133         switch (vcpu->arch.sie_block->iprcc & ~PGM_PER) {
 134         case PGM_AFX_TRANSLATION:
 135         case PGM_ASX_TRANSLATION:
 136         case PGM_EX_TRANSLATION:
 137         case PGM_LFX_TRANSLATION:
 138         case PGM_LSTE_SEQUENCE:
 139         case PGM_LSX_TRANSLATION:
 140         case PGM_LX_TRANSLATION:
 141         case PGM_PRIMARY_AUTHORITY:
 142         case PGM_SECONDARY_AUTHORITY:
 143         case PGM_SPACE_SWITCH:
 144                 pgm_info->trans_exc_code = vcpu->arch.sie_block->tecmc;
 145                 break;
 146         case PGM_ALEN_TRANSLATION:
 147         case PGM_ALE_SEQUENCE:
 148         case PGM_ASTE_INSTANCE:
 149         case PGM_ASTE_SEQUENCE:
 150         case PGM_ASTE_VALIDITY:
 151         case PGM_EXTENDED_AUTHORITY:
 152                 pgm_info->exc_access_id = vcpu->arch.sie_block->eai;
 153                 break;
 154         case PGM_ASCE_TYPE:
 155         case PGM_PAGE_TRANSLATION:
 156         case PGM_REGION_FIRST_TRANS:
 157         case PGM_REGION_SECOND_TRANS:
 158         case PGM_REGION_THIRD_TRANS:
 159         case PGM_SEGMENT_TRANSLATION:
 160                 pgm_info->trans_exc_code = vcpu->arch.sie_block->tecmc;
 161                 pgm_info->exc_access_id  = vcpu->arch.sie_block->eai;
 162                 pgm_info->op_access_id  = vcpu->arch.sie_block->oai;
 163                 break;
 164         case PGM_MONITOR:
 165                 pgm_info->mon_class_nr = vcpu->arch.sie_block->mcn;
 166                 pgm_info->mon_code = vcpu->arch.sie_block->tecmc;
 167                 break;
 168         case PGM_VECTOR_PROCESSING:
 169         case PGM_DATA:
 170                 pgm_info->data_exc_code = vcpu->arch.sie_block->dxc;
 171                 break;
 172         case PGM_PROTECTION:
 173                 pgm_info->trans_exc_code = vcpu->arch.sie_block->tecmc;
 174                 pgm_info->exc_access_id  = vcpu->arch.sie_block->eai;
 175                 break;
 176         default:
 177                 break;
 178         }
 179
 180         if (vcpu->arch.sie_block->iprcc & PGM_PER) {
 181                 pgm_info->per_code = vcpu->arch.sie_block->perc;
 182                 pgm_info->per_atmid = vcpu->arch.sie_block->peratmid;
 183                 pgm_info->per_address = vcpu->arch.sie_block->peraddr;
 184                 pgm_info->per_access_id = vcpu->arch.sie_block->peraid;
 185         }
 186 }
 187
 188 /*
 189  * restore ITDB to program-interruption TDB in guest lowcore
 190  * and set TX abort indication if required
 191 */
 192 static int handle_itdb(struct kvm_vcpu *vcpu)
 193 {
 194         struct kvm_s390_itdb *itdb;
 195         int rc;
 196
 197         if (!IS_TE_ENABLED(vcpu) || !IS_ITDB_VALID(vcpu))
 198                 return 0;
 199         if (current->thread.per_flags & PER_FLAG_NO_TE)
 200                 return 0;
 201         itdb = (struct kvm_s390_itdb *)vcpu->arch.sie_block->itdba;
 202         rc = write_guest_lc(vcpu, __LC_PGM_TDB, itdb, sizeof(*itdb));
 203         if (rc)
 204                 return rc;
 205         memset(itdb, 0, sizeof(*itdb));
 206
 207         return 0;
 208 }
 209
 210 #define per_event(vcpu) (vcpu->arch.sie_block->iprcc & PGM_PER)
 211
 212 static int handle_prog(struct kvm_vcpu *vcpu)
 213 {
 214         struct kvm_s390_pgm_info pgm_info;
 215         psw_t psw;
 216         int rc;
 217
 218         vcpu->stat.exit_program_interruption++;
 219
 220         if (guestdbg_enabled(vcpu) && per_event(vcpu)) {
 221                 kvm_s390_handle_per_event(vcpu);
 222                 /* the interrupt might have been filtered out completely */
 223                 if (vcpu->arch.sie_block->iprcc == 0)
 224                         return 0;
 225         }
 226
 227         trace_kvm_s390_intercept_prog(vcpu, vcpu->arch.sie_block->iprcc);
 228         if (vcpu->arch.sie_block->iprcc == PGM_SPECIFICATION) {
 229                 rc = read_guest_lc(vcpu, __LC_PGM_NEW_PSW, &psw, sizeof(psw_t));
 230                 if (rc)
 231                         return rc;
 232                 /* Avoid endless loops of specification exceptions */
 233                 if (!is_valid_psw(&psw))
 234                         return -EOPNOTSUPP;
 235         }
 236         rc = handle_itdb(vcpu);
 237         if (rc)
 238                 return rc;
 239
 240         __extract_prog_irq(vcpu, &pgm_info);
 241         return kvm_s390_inject_prog_irq(vcpu, &pgm_info);
 242 }
 243
 244 static int handle_instruction_and_prog(struct kvm_vcpu *vcpu)
 245 {
 246         int rc, rc2;
 247
 248         vcpu->stat.exit_instr_and_program++;
 249         rc = handle_instruction(vcpu);
 250         rc2 = handle_prog(vcpu);
 251
 252         if (rc == -EOPNOTSUPP)
 253                 vcpu->arch.sie_block->icptcode = 0x04;
 254         if (rc)
 255                 return rc;
 256         return rc2;
 257 }
 258
 259 /**
 260  * handle_external_interrupt - used for external interruption interceptions
 261  *
 262  * This interception only occurs if the CPUSTAT_EXT_INT bit was set, or if
 263  * the new PSW does not have external interrupts disabled. In the first case,
 264  * we've got to deliver the interrupt manually, and in the second case, we
 265  * drop to userspace to handle the situation there.
 266  */
 267 static int handle_external_interrupt(struct kvm_vcpu *vcpu)
 268 {
 269         u16 eic = vcpu->arch.sie_block->eic;
 270         struct kvm_s390_irq irq;
 271         psw_t newpsw;
 272         int rc;
 273
 274         vcpu->stat.exit_external_interrupt++;
 275
 276         rc = read_guest_lc(vcpu, __LC_EXT_NEW_PSW, &newpsw, sizeof(psw_t));
 277         if (rc)
 278                 return rc;
 279         /* We can not handle clock comparator or timer interrupt with bad PSW */
 280         if ((eic == EXT_IRQ_CLK_COMP || eic == EXT_IRQ_CPU_TIMER) &&
 281             (newpsw.mask & PSW_MASK_EXT))
 282                 return -EOPNOTSUPP;
 283
 284         switch (eic) {
 285         case EXT_IRQ_CLK_COMP:
 286                 irq.type = KVM_S390_INT_CLOCK_COMP;
 287                 break;
 288         case EXT_IRQ_CPU_TIMER:
 289                 irq.type = KVM_S390_INT_CPU_TIMER;
 290                 break;
 291         case EXT_IRQ_EXTERNAL_CALL:
 292                 irq.type = KVM_S390_INT_EXTERNAL_CALL;
 293                 irq.u.extcall.code = vcpu->arch.sie_block->extcpuaddr;
 294                 rc = kvm_s390_inject_vcpu(vcpu, &irq);
 295                 /* ignore if another external call is already pending */
 296                 if (rc == -EBUSY)
 297                         return 0;
 298                 return rc;
 299         default:
 300                 return -EOPNOTSUPP;
 301         }
 302
 303         return kvm_s390_inject_vcpu(vcpu, &irq);
 304 }
 305
 306 /**
 307  * Handle MOVE PAGE partial execution interception.
 308  *
 309  * This interception can only happen for guests with DAT disabled and
 310  * addresses that are currently not mapped in the host. Thus we try to
 311  * set up the mappings for the corresponding user pages here (or throw
 312  * addressing exceptions in case of illegal guest addresses).
 313  */
 314 static int handle_mvpg_pei(struct kvm_vcpu *vcpu)
 315 {
 316         unsigned long srcaddr, dstaddr;
 317         int reg1, reg2, rc;
 318
 319         kvm_s390_get_regs_rre(vcpu, &reg1, &reg2);
 320
 321         /* Make sure that the source is paged-in */
 322         rc = guest_translate_address(vcpu, vcpu->run->s.regs.gprs[reg2],
 323                                      reg2, &srcaddr, 0);
 324         if (rc)
 325                 return kvm_s390_inject_prog_cond(vcpu, rc);
 326         rc = kvm_arch_fault_in_page(vcpu, srcaddr, 0);
 327         if (rc != 0)
 328                 return rc;
 329
 330         /* Make sure that the destination is paged-in */
 331         rc = guest_translate_address(vcpu, vcpu->run->s.regs.gprs[reg1],
 332                                      reg1, &dstaddr, 1);
 333         if (rc)
 334                 return kvm_s390_inject_prog_cond(vcpu, rc);
 335         rc = kvm_arch_fault_in_page(vcpu, dstaddr, 1);
 336         if (rc != 0)
 337                 return rc;
 338
 339         kvm_s390_rewind_psw(vcpu, 4);
 340
 341         return 0;
 342 }
 343
 344 static int handle_partial_execution(struct kvm_vcpu *vcpu)
 345 {
 346         if (vcpu->arch.sie_block->ipa == 0xb254)        /* MVPG */
 347                 return handle_mvpg_pei(vcpu);
 348         if (vcpu->arch.sie_block->ipa >> 8 == 0xae)     /* SIGP */
 349                 return kvm_s390_handle_sigp_pei(vcpu);
 350
 351         return -EOPNOTSUPP;
 352 }
 353
 354 static const intercept_handler_t intercept_funcs[] = {
 355         [0x00 >> 2] = handle_noop,
 356         [0x04 >> 2] = handle_instruction,
 357         [0x08 >> 2] = handle_prog,
 358         [0x0C >> 2] = handle_instruction_and_prog,
 359         [0x10 >> 2] = handle_noop,
 360         [0x14 >> 2] = handle_external_interrupt,
 361         [0x18 >> 2] = handle_noop,
 362         [0x1C >> 2] = kvm_s390_handle_wait,
 363         [0x20 >> 2] = handle_validity,
 364         [0x28 >> 2] = handle_stop,
 365         [0x38 >> 2] = handle_partial_execution,
 366 };
 367
 368 int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
 369 {
 370         intercept_handler_t func;
 371         u8 code = vcpu->arch.sie_block->icptcode;
 372
 373         if (code & 3 || (code >> 2) >= ARRAY_SIZE(intercept_funcs))
 374                 return -EOPNOTSUPP;
 375         func = intercept_funcs[code >> 2];
 376         if (func)
 377                 return func(vcpu);
 378         return -EOPNOTSUPP;
 379 }