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         int rc = 0;
  72         unsigned int action_bits;
  73
  74         vcpu->stat.exit_stop_request++;
  75         trace_kvm_s390_stop_request(vcpu->arch.local_int.action_bits);
  76
  77         action_bits = vcpu->arch.local_int.action_bits;
  78
  79         if (!(action_bits & ACTION_STOP_ON_STOP))
  80                 return 0;
  81
  82         if (action_bits & ACTION_STORE_ON_STOP) {
  83                 rc = kvm_s390_vcpu_store_status(vcpu,
  84                                                 KVM_S390_STORE_STATUS_NOADDR);
  85                 if (rc)
  86                         return rc;
  87         }
  88
  89         if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm))
  90                 kvm_s390_vcpu_stop(vcpu);
  91         return -EOPNOTSUPP;
  92 }
  93
  94 static int handle_validity(struct kvm_vcpu *vcpu)
  95 {
  96         int viwhy = vcpu->arch.sie_block->ipb >> 16;
  97
  98         vcpu->stat.exit_validity++;
  99         trace_kvm_s390_intercept_validity(vcpu, viwhy);
 100         WARN_ONCE(true, "kvm: unhandled validity intercept 0x%x\n", viwhy);
 101         return -EOPNOTSUPP;
 102 }
 103
 104 static int handle_instruction(struct kvm_vcpu *vcpu)
 105 {
 106         intercept_handler_t handler;
 107
 108         vcpu->stat.exit_instruction++;
 109         trace_kvm_s390_intercept_instruction(vcpu,
 110                                              vcpu->arch.sie_block->ipa,
 111                                              vcpu->arch.sie_block->ipb);
 112         handler = instruction_handlers[vcpu->arch.sie_block->ipa >> 8];
 113         if (handler)
 114                 return handler(vcpu);
 115         return -EOPNOTSUPP;
 116 }
 117
 118 static void __extract_prog_irq(struct kvm_vcpu *vcpu,
 119                                struct kvm_s390_pgm_info *pgm_info)
 120 {
 121         memset(pgm_info, 0, sizeof(struct kvm_s390_pgm_info));
 122         pgm_info->code = vcpu->arch.sie_block->iprcc;
 123
 124         switch (vcpu->arch.sie_block->iprcc & ~PGM_PER) {
 125         case PGM_AFX_TRANSLATION:
 126         case PGM_ASX_TRANSLATION:
 127         case PGM_EX_TRANSLATION:
 128         case PGM_LFX_TRANSLATION:
 129         case PGM_LSTE_SEQUENCE:
 130         case PGM_LSX_TRANSLATION:
 131         case PGM_LX_TRANSLATION:
 132         case PGM_PRIMARY_AUTHORITY:
 133         case PGM_SECONDARY_AUTHORITY:
 134         case PGM_SPACE_SWITCH:
 135                 pgm_info->trans_exc_code = vcpu->arch.sie_block->tecmc;
 136                 break;
 137         case PGM_ALEN_TRANSLATION:
 138         case PGM_ALE_SEQUENCE:
 139         case PGM_ASTE_INSTANCE:
 140         case PGM_ASTE_SEQUENCE:
 141         case PGM_ASTE_VALIDITY:
 142         case PGM_EXTENDED_AUTHORITY:
 143                 pgm_info->exc_access_id = vcpu->arch.sie_block->eai;
 144                 break;
 145         case PGM_ASCE_TYPE:
 146         case PGM_PAGE_TRANSLATION:
 147         case PGM_REGION_FIRST_TRANS:
 148         case PGM_REGION_SECOND_TRANS:
 149         case PGM_REGION_THIRD_TRANS:
 150         case PGM_SEGMENT_TRANSLATION:
 151                 pgm_info->trans_exc_code = vcpu->arch.sie_block->tecmc;
 152                 pgm_info->exc_access_id  = vcpu->arch.sie_block->eai;
 153                 pgm_info->op_access_id  = vcpu->arch.sie_block->oai;
 154                 break;
 155         case PGM_MONITOR:
 156                 pgm_info->mon_class_nr = vcpu->arch.sie_block->mcn;
 157                 pgm_info->mon_code = vcpu->arch.sie_block->tecmc;
 158                 break;
 159         case PGM_DATA:
 160                 pgm_info->data_exc_code = vcpu->arch.sie_block->dxc;
 161                 break;
 162         case PGM_PROTECTION:
 163                 pgm_info->trans_exc_code = vcpu->arch.sie_block->tecmc;
 164                 pgm_info->exc_access_id  = vcpu->arch.sie_block->eai;
 165                 break;
 166         default:
 167                 break;
 168         }
 169
 170         if (vcpu->arch.sie_block->iprcc & PGM_PER) {
 171                 pgm_info->per_code = vcpu->arch.sie_block->perc;
 172                 pgm_info->per_atmid = vcpu->arch.sie_block->peratmid;
 173                 pgm_info->per_address = vcpu->arch.sie_block->peraddr;
 174                 pgm_info->per_access_id = vcpu->arch.sie_block->peraid;
 175         }
 176 }
 177
 178 /*
 179  * restore ITDB to program-interruption TDB in guest lowcore
 180  * and set TX abort indication if required
 181 */
 182 static int handle_itdb(struct kvm_vcpu *vcpu)
 183 {
 184         struct kvm_s390_itdb *itdb;
 185         int rc;
 186
 187         if (!IS_TE_ENABLED(vcpu) || !IS_ITDB_VALID(vcpu))
 188                 return 0;
 189         if (current->thread.per_flags & PER_FLAG_NO_TE)
 190                 return 0;
 191         itdb = (struct kvm_s390_itdb *)vcpu->arch.sie_block->itdba;
 192         rc = write_guest_lc(vcpu, __LC_PGM_TDB, itdb, sizeof(*itdb));
 193         if (rc)
 194                 return rc;
 195         memset(itdb, 0, sizeof(*itdb));
 196
 197         return 0;
 198 }
 199
 200 #define per_event(vcpu) (vcpu->arch.sie_block->iprcc & PGM_PER)
 201
 202 static int handle_prog(struct kvm_vcpu *vcpu)
 203 {
 204         struct kvm_s390_pgm_info pgm_info;
 205         psw_t psw;
 206         int rc;
 207
 208         vcpu->stat.exit_program_interruption++;
 209
 210         if (guestdbg_enabled(vcpu) && per_event(vcpu)) {
 211                 kvm_s390_handle_per_event(vcpu);
 212                 /* the interrupt might have been filtered out completely */
 213                 if (vcpu->arch.sie_block->iprcc == 0)
 214                         return 0;
 215         }
 216
 217         trace_kvm_s390_intercept_prog(vcpu, vcpu->arch.sie_block->iprcc);
 218         if (vcpu->arch.sie_block->iprcc == PGM_SPECIFICATION) {
 219                 rc = read_guest_lc(vcpu, __LC_PGM_NEW_PSW, &psw, sizeof(psw_t));
 220                 if (rc)
 221                         return rc;
 222                 /* Avoid endless loops of specification exceptions */
 223                 if (!is_valid_psw(&psw))
 224                         return -EOPNOTSUPP;
 225         }
 226         rc = handle_itdb(vcpu);
 227         if (rc)
 228                 return rc;
 229
 230         __extract_prog_irq(vcpu, &pgm_info);
 231         return kvm_s390_inject_prog_irq(vcpu, &pgm_info);
 232 }
 233
 234 static int handle_instruction_and_prog(struct kvm_vcpu *vcpu)
 235 {
 236         int rc, rc2;
 237
 238         vcpu->stat.exit_instr_and_program++;
 239         rc = handle_instruction(vcpu);
 240         rc2 = handle_prog(vcpu);
 241
 242         if (rc == -EOPNOTSUPP)
 243                 vcpu->arch.sie_block->icptcode = 0x04;
 244         if (rc)
 245                 return rc;
 246         return rc2;
 247 }
 248
 249 /**
 250  * handle_external_interrupt - used for external interruption interceptions
 251  *
 252  * This interception only occurs if the CPUSTAT_EXT_INT bit was set, or if
 253  * the new PSW does not have external interrupts disabled. In the first case,
 254  * we've got to deliver the interrupt manually, and in the second case, we
 255  * drop to userspace to handle the situation there.
 256  */
 257 static int handle_external_interrupt(struct kvm_vcpu *vcpu)
 258 {
 259         u16 eic = vcpu->arch.sie_block->eic;
 260         struct kvm_s390_irq irq;
 261         psw_t newpsw;
 262         int rc;
 263
 264         vcpu->stat.exit_external_interrupt++;
 265
 266         rc = read_guest_lc(vcpu, __LC_EXT_NEW_PSW, &newpsw, sizeof(psw_t));
 267         if (rc)
 268                 return rc;
 269         /* We can not handle clock comparator or timer interrupt with bad PSW */
 270         if ((eic == EXT_IRQ_CLK_COMP || eic == EXT_IRQ_CPU_TIMER) &&
 271             (newpsw.mask & PSW_MASK_EXT))
 272                 return -EOPNOTSUPP;
 273
 274         switch (eic) {
 275         case EXT_IRQ_CLK_COMP:
 276                 irq.type = KVM_S390_INT_CLOCK_COMP;
 277                 break;
 278         case EXT_IRQ_CPU_TIMER:
 279                 irq.type = KVM_S390_INT_CPU_TIMER;
 280                 break;
 281         case EXT_IRQ_EXTERNAL_CALL:
 282                 if (kvm_s390_si_ext_call_pending(vcpu))
 283                         return 0;
 284                 irq.type = KVM_S390_INT_EXTERNAL_CALL;
 285                 irq.u.extcall.code = vcpu->arch.sie_block->extcpuaddr;
 286                 break;
 287         default:
 288                 return -EOPNOTSUPP;
 289         }
 290
 291         return kvm_s390_inject_vcpu(vcpu, &irq);
 292 }
 293
 294 /**
 295  * Handle MOVE PAGE partial execution interception.
 296  *
 297  * This interception can only happen for guests with DAT disabled and
 298  * addresses that are currently not mapped in the host. Thus we try to
 299  * set up the mappings for the corresponding user pages here (or throw
 300  * addressing exceptions in case of illegal guest addresses).
 301  */
 302 static int handle_mvpg_pei(struct kvm_vcpu *vcpu)
 303 {
 304         unsigned long srcaddr, dstaddr;
 305         int reg1, reg2, rc;
 306
 307         kvm_s390_get_regs_rre(vcpu, &reg1, &reg2);
 308
 309         /* Make sure that the source is paged-in */
 310         srcaddr = kvm_s390_real_to_abs(vcpu, vcpu->run->s.regs.gprs[reg2]);
 311         if (kvm_is_error_gpa(vcpu->kvm, srcaddr))
 312                 return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
 313         rc = kvm_arch_fault_in_page(vcpu, srcaddr, 0);
 314         if (rc != 0)
 315                 return rc;
 316
 317         /* Make sure that the destination is paged-in */
 318         dstaddr = kvm_s390_real_to_abs(vcpu, vcpu->run->s.regs.gprs[reg1]);
 319         if (kvm_is_error_gpa(vcpu->kvm, dstaddr))
 320                 return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
 321         rc = kvm_arch_fault_in_page(vcpu, dstaddr, 1);
 322         if (rc != 0)
 323                 return rc;
 324
 325         kvm_s390_rewind_psw(vcpu, 4);
 326
 327         return 0;
 328 }
 329
 330 static int handle_partial_execution(struct kvm_vcpu *vcpu)
 331 {
 332         if (vcpu->arch.sie_block->ipa == 0xb254)        /* MVPG */
 333                 return handle_mvpg_pei(vcpu);
 334         if (vcpu->arch.sie_block->ipa >> 8 == 0xae)     /* SIGP */
 335                 return kvm_s390_handle_sigp_pei(vcpu);
 336
 337         return -EOPNOTSUPP;
 338 }
 339
 340 static const intercept_handler_t intercept_funcs[] = {
 341         [0x00 >> 2] = handle_noop,
 342         [0x04 >> 2] = handle_instruction,
 343         [0x08 >> 2] = handle_prog,
 344         [0x0C >> 2] = handle_instruction_and_prog,
 345         [0x10 >> 2] = handle_noop,
 346         [0x14 >> 2] = handle_external_interrupt,
 347         [0x18 >> 2] = handle_noop,
 348         [0x1C >> 2] = kvm_s390_handle_wait,
 349         [0x20 >> 2] = handle_validity,
 350         [0x28 >> 2] = handle_stop,
 351         [0x38 >> 2] = handle_partial_execution,
 352 };
 353
 354 int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
 355 {
 356         intercept_handler_t func;
 357         u8 code = vcpu->arch.sie_block->icptcode;
 358
 359         if (code & 3 || (code >> 2) >= ARRAY_SIZE(intercept_funcs))
 360                 return -EOPNOTSUPP;
 361         func = intercept_funcs[code >> 2];
 362         if (func)
 363                 return func(vcpu);
 364         return -EOPNOTSUPP;
 365 }