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 0x10:
  58                 vcpu->stat.exit_external_request++;
  59                 break;
  60         default:
  61                 break; /* nothing */
  62         }
  63         return 0;
  64 }
  65
  66 static int handle_stop(struct kvm_vcpu *vcpu)
  67 {
  68         struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;
  69         int rc = 0;
  70         uint8_t flags, stop_pending;
  71
  72         vcpu->stat.exit_stop_request++;
  73
  74         /* delay the stop if any non-stop irq is pending */
  75         if (kvm_s390_vcpu_has_irq(vcpu, 1))
  76                 return 0;
  77
  78         /* avoid races with the injection/SIGP STOP code */
  79         spin_lock(&li->lock);
  80         flags = li->irq.stop.flags;
  81         stop_pending = kvm_s390_is_stop_irq_pending(vcpu);
  82         spin_unlock(&li->lock);
  83
  84         trace_kvm_s390_stop_request(stop_pending, flags);
  85         if (!stop_pending)
  86                 return 0;
  87
  88         if (flags & KVM_S390_STOP_FLAG_STORE_STATUS) {
  89                 rc = kvm_s390_vcpu_store_status(vcpu,
  90                                                 KVM_S390_STORE_STATUS_NOADDR);
  91                 if (rc)
  92                         return rc;
  93         }
  94
  95         if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm))
  96                 kvm_s390_vcpu_stop(vcpu);
  97         return -EOPNOTSUPP;
  98 }
  99
 100 static int handle_validity(struct kvm_vcpu *vcpu)
 101 {
 102         int viwhy = vcpu->arch.sie_block->ipb >> 16;
 103
 104         vcpu->stat.exit_validity++;
 105         trace_kvm_s390_intercept_validity(vcpu, viwhy);
 106         WARN_ONCE(true, "kvm: unhandled validity intercept 0x%x\n", viwhy);
 107         return -EOPNOTSUPP;
 108 }
 109
 110 static int handle_instruction(struct kvm_vcpu *vcpu)
 111 {
 112         intercept_handler_t handler;
 113
 114         vcpu->stat.exit_instruction++;
 115         trace_kvm_s390_intercept_instruction(vcpu,
 116                                              vcpu->arch.sie_block->ipa,
 117                                              vcpu->arch.sie_block->ipb);
 118         handler = instruction_handlers[vcpu->arch.sie_block->ipa >> 8];
 119         if (handler)
 120                 return handler(vcpu);
 121         return -EOPNOTSUPP;
 122 }
 123
 124 static void __extract_prog_irq(struct kvm_vcpu *vcpu,
 125                                struct kvm_s390_pgm_info *pgm_info)
 126 {
 127         memset(pgm_info, 0, sizeof(struct kvm_s390_pgm_info));
 128         pgm_info->code = vcpu->arch.sie_block->iprcc;
 129
 130         switch (vcpu->arch.sie_block->iprcc & ~PGM_PER) {
 131         case PGM_AFX_TRANSLATION:
 132         case PGM_ASX_TRANSLATION:
 133         case PGM_EX_TRANSLATION:
 134         case PGM_LFX_TRANSLATION:
 135         case PGM_LSTE_SEQUENCE:
 136         case PGM_LSX_TRANSLATION:
 137         case PGM_LX_TRANSLATION:
 138         case PGM_PRIMARY_AUTHORITY:
 139         case PGM_SECONDARY_AUTHORITY:
 140         case PGM_SPACE_SWITCH:
 141                 pgm_info->trans_exc_code = vcpu->arch.sie_block->tecmc;
 142                 break;
 143         case PGM_ALEN_TRANSLATION:
 144         case PGM_ALE_SEQUENCE:
 145         case PGM_ASTE_INSTANCE:
 146         case PGM_ASTE_SEQUENCE:
 147         case PGM_ASTE_VALIDITY:
 148         case PGM_EXTENDED_AUTHORITY:
 149                 pgm_info->exc_access_id = vcpu->arch.sie_block->eai;
 150                 break;
 151         case PGM_ASCE_TYPE:
 152         case PGM_PAGE_TRANSLATION:
 153         case PGM_REGION_FIRST_TRANS:
 154         case PGM_REGION_SECOND_TRANS:
 155         case PGM_REGION_THIRD_TRANS:
 156         case PGM_SEGMENT_TRANSLATION:
 157                 pgm_info->trans_exc_code = vcpu->arch.sie_block->tecmc;
 158                 pgm_info->exc_access_id  = vcpu->arch.sie_block->eai;
 159                 pgm_info->op_access_id  = vcpu->arch.sie_block->oai;
 160                 break;
 161         case PGM_MONITOR:
 162                 pgm_info->mon_class_nr = vcpu->arch.sie_block->mcn;
 163                 pgm_info->mon_code = vcpu->arch.sie_block->tecmc;
 164                 break;
 165         case PGM_VECTOR_PROCESSING:
 166         case PGM_DATA:
 167                 pgm_info->data_exc_code = vcpu->arch.sie_block->dxc;
 168                 break;
 169         case PGM_PROTECTION:
 170                 pgm_info->trans_exc_code = vcpu->arch.sie_block->tecmc;
 171                 pgm_info->exc_access_id  = vcpu->arch.sie_block->eai;
 172                 break;
 173         default:
 174                 break;
 175         }
 176
 177         if (vcpu->arch.sie_block->iprcc & PGM_PER) {
 178                 pgm_info->per_code = vcpu->arch.sie_block->perc;
 179                 pgm_info->per_atmid = vcpu->arch.sie_block->peratmid;
 180                 pgm_info->per_address = vcpu->arch.sie_block->peraddr;
 181                 pgm_info->per_access_id = vcpu->arch.sie_block->peraid;
 182         }
 183 }
 184
 185 /*
 186  * restore ITDB to program-interruption TDB in guest lowcore
 187  * and set TX abort indication if required
 188 */
 189 static int handle_itdb(struct kvm_vcpu *vcpu)
 190 {
 191         struct kvm_s390_itdb *itdb;
 192         int rc;
 193
 194         if (!IS_TE_ENABLED(vcpu) || !IS_ITDB_VALID(vcpu))
 195                 return 0;
 196         if (current->thread.per_flags & PER_FLAG_NO_TE)
 197                 return 0;
 198         itdb = (struct kvm_s390_itdb *)vcpu->arch.sie_block->itdba;
 199         rc = write_guest_lc(vcpu, __LC_PGM_TDB, itdb, sizeof(*itdb));
 200         if (rc)
 201                 return rc;
 202         memset(itdb, 0, sizeof(*itdb));
 203
 204         return 0;
 205 }
 206
 207 #define per_event(vcpu) (vcpu->arch.sie_block->iprcc & PGM_PER)
 208
 209 static int handle_prog(struct kvm_vcpu *vcpu)
 210 {
 211         struct kvm_s390_pgm_info pgm_info;
 212         psw_t psw;
 213         int rc;
 214
 215         vcpu->stat.exit_program_interruption++;
 216
 217         if (guestdbg_enabled(vcpu) && per_event(vcpu)) {
 218                 kvm_s390_handle_per_event(vcpu);
 219                 /* the interrupt might have been filtered out completely */
 220                 if (vcpu->arch.sie_block->iprcc == 0)
 221                         return 0;
 222         }
 223
 224         trace_kvm_s390_intercept_prog(vcpu, vcpu->arch.sie_block->iprcc);
 225         if (vcpu->arch.sie_block->iprcc == PGM_SPECIFICATION) {
 226                 rc = read_guest_lc(vcpu, __LC_PGM_NEW_PSW, &psw, sizeof(psw_t));
 227                 if (rc)
 228                         return rc;
 229                 /* Avoid endless loops of specification exceptions */
 230                 if (!is_valid_psw(&psw))
 231                         return -EOPNOTSUPP;
 232         }
 233         rc = handle_itdb(vcpu);
 234         if (rc)
 235                 return rc;
 236
 237         __extract_prog_irq(vcpu, &pgm_info);
 238         return kvm_s390_inject_prog_irq(vcpu, &pgm_info);
 239 }
 240
 241 /**
 242  * handle_external_interrupt - used for external interruption interceptions
 243  *
 244  * This interception only occurs if the CPUSTAT_EXT_INT bit was set, or if
 245  * the new PSW does not have external interrupts disabled. In the first case,
 246  * we've got to deliver the interrupt manually, and in the second case, we
 247  * drop to userspace to handle the situation there.
 248  */
 249 static int handle_external_interrupt(struct kvm_vcpu *vcpu)
 250 {
 251         u16 eic = vcpu->arch.sie_block->eic;
 252         struct kvm_s390_irq irq;
 253         psw_t newpsw;
 254         int rc;
 255
 256         vcpu->stat.exit_external_interrupt++;
 257
 258         rc = read_guest_lc(vcpu, __LC_EXT_NEW_PSW, &newpsw, sizeof(psw_t));
 259         if (rc)
 260                 return rc;
 261         /* We can not handle clock comparator or timer interrupt with bad PSW */
 262         if ((eic == EXT_IRQ_CLK_COMP || eic == EXT_IRQ_CPU_TIMER) &&
 263             (newpsw.mask & PSW_MASK_EXT))
 264                 return -EOPNOTSUPP;
 265
 266         switch (eic) {
 267         case EXT_IRQ_CLK_COMP:
 268                 irq.type = KVM_S390_INT_CLOCK_COMP;
 269                 break;
 270         case EXT_IRQ_CPU_TIMER:
 271                 irq.type = KVM_S390_INT_CPU_TIMER;
 272                 break;
 273         case EXT_IRQ_EXTERNAL_CALL:
 274                 irq.type = KVM_S390_INT_EXTERNAL_CALL;
 275                 irq.u.extcall.code = vcpu->arch.sie_block->extcpuaddr;
 276                 rc = kvm_s390_inject_vcpu(vcpu, &irq);
 277                 /* ignore if another external call is already pending */
 278                 if (rc == -EBUSY)
 279                         return 0;
 280                 return rc;
 281         default:
 282                 return -EOPNOTSUPP;
 283         }
 284
 285         return kvm_s390_inject_vcpu(vcpu, &irq);
 286 }
 287
 288 /**
 289  * Handle MOVE PAGE partial execution interception.
 290  *
 291  * This interception can only happen for guests with DAT disabled and
 292  * addresses that are currently not mapped in the host. Thus we try to
 293  * set up the mappings for the corresponding user pages here (or throw
 294  * addressing exceptions in case of illegal guest addresses).
 295  */
 296 static int handle_mvpg_pei(struct kvm_vcpu *vcpu)
 297 {
 298         unsigned long srcaddr, dstaddr;
 299         int reg1, reg2, rc;
 300
 301         kvm_s390_get_regs_rre(vcpu, &reg1, &reg2);
 302
 303         /* Make sure that the source is paged-in */
 304         rc = guest_translate_address(vcpu, vcpu->run->s.regs.gprs[reg2],
 305                                      reg2, &srcaddr, 0);
 306         if (rc)
 307                 return kvm_s390_inject_prog_cond(vcpu, rc);
 308         rc = kvm_arch_fault_in_page(vcpu, srcaddr, 0);
 309         if (rc != 0)
 310                 return rc;
 311
 312         /* Make sure that the destination is paged-in */
 313         rc = guest_translate_address(vcpu, vcpu->run->s.regs.gprs[reg1],
 314                                      reg1, &dstaddr, 1);
 315         if (rc)
 316                 return kvm_s390_inject_prog_cond(vcpu, rc);
 317         rc = kvm_arch_fault_in_page(vcpu, dstaddr, 1);
 318         if (rc != 0)
 319                 return rc;
 320
 321         kvm_s390_rewind_psw(vcpu, 4);
 322
 323         return 0;
 324 }
 325
 326 static int handle_partial_execution(struct kvm_vcpu *vcpu)
 327 {
 328         if (vcpu->arch.sie_block->ipa == 0xb254)        /* MVPG */
 329                 return handle_mvpg_pei(vcpu);
 330         if (vcpu->arch.sie_block->ipa >> 8 == 0xae)     /* SIGP */
 331                 return kvm_s390_handle_sigp_pei(vcpu);
 332
 333         return -EOPNOTSUPP;
 334 }
 335
 336 int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
 337 {
 338         if (kvm_is_ucontrol(vcpu->kvm))
 339                 return -EOPNOTSUPP;
 340
 341         switch (vcpu->arch.sie_block->icptcode) {
 342         case 0x10:
 343         case 0x18:
 344                 return handle_noop(vcpu);
 345         case 0x04:
 346                 return handle_instruction(vcpu);
 347         case 0x08:
 348                 return handle_prog(vcpu);
 349         case 0x14:
 350                 return handle_external_interrupt(vcpu);
 351         case 0x1c:
 352                 return kvm_s390_handle_wait(vcpu);
 353         case 0x20:
 354                 return handle_validity(vcpu);
 355         case 0x28:
 356                 return handle_stop(vcpu);
 357         case 0x38:
 358                 return handle_partial_execution(vcpu);
 359         default:
 360                 return -EOPNOTSUPP;
 361         }
 362 }