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 static int handle_noop(struct kvm_vcpu *vcpu)
  42 {
  43         switch (vcpu->arch.sie_block->icptcode) {
  44         case 0x0:
  45                 vcpu->stat.exit_null++;
  46                 break;
  47         case 0x10:
  48                 vcpu->stat.exit_external_request++;
  49                 break;
  50         default:
  51                 break; /* nothing */
  52         }
  53         return 0;
  54 }
  55
  56 static int handle_stop(struct kvm_vcpu *vcpu)
  57 {
  58         int rc = 0;
  59
  60         vcpu->stat.exit_stop_request++;
  61         spin_lock_bh(&vcpu->arch.local_int.lock);
  62
  63         trace_kvm_s390_stop_request(vcpu->arch.local_int.action_bits);
  64
  65         if (vcpu->arch.local_int.action_bits & ACTION_STOP_ON_STOP) {
  66                 kvm_s390_vcpu_stop(vcpu);
  67                 vcpu->arch.local_int.action_bits &= ~ACTION_STOP_ON_STOP;
  68                 VCPU_EVENT(vcpu, 3, "%s", "cpu stopped");
  69                 rc = -EOPNOTSUPP;
  70         }
  71
  72         if (vcpu->arch.local_int.action_bits & ACTION_STORE_ON_STOP) {
  73                 vcpu->arch.local_int.action_bits &= ~ACTION_STORE_ON_STOP;
  74                 /* store status must be called unlocked. Since local_int.lock
  75                  * only protects local_int.* and not guest memory we can give
  76                  * up the lock here */
  77                 spin_unlock_bh(&vcpu->arch.local_int.lock);
  78                 rc = kvm_s390_vcpu_store_status(vcpu,
  79                                                 KVM_S390_STORE_STATUS_NOADDR);
  80                 if (rc >= 0)
  81                         rc = -EOPNOTSUPP;
  82         } else
  83                 spin_unlock_bh(&vcpu->arch.local_int.lock);
  84         return rc;
  85 }
  86
  87 static int handle_validity(struct kvm_vcpu *vcpu)
  88 {
  89         int viwhy = vcpu->arch.sie_block->ipb >> 16;
  90
  91         vcpu->stat.exit_validity++;
  92         trace_kvm_s390_intercept_validity(vcpu, viwhy);
  93         WARN_ONCE(true, "kvm: unhandled validity intercept 0x%x\n", viwhy);
  94         return -EOPNOTSUPP;
  95 }
  96
  97 static int handle_instruction(struct kvm_vcpu *vcpu)
  98 {
  99         intercept_handler_t handler;
 100
 101         vcpu->stat.exit_instruction++;
 102         trace_kvm_s390_intercept_instruction(vcpu,
 103                                              vcpu->arch.sie_block->ipa,
 104                                              vcpu->arch.sie_block->ipb);
 105         handler = instruction_handlers[vcpu->arch.sie_block->ipa >> 8];
 106         if (handler)
 107                 return handler(vcpu);
 108         return -EOPNOTSUPP;
 109 }
 110
 111 static void __extract_prog_irq(struct kvm_vcpu *vcpu,
 112                                struct kvm_s390_pgm_info *pgm_info)
 113 {
 114         memset(pgm_info, 0, sizeof(struct kvm_s390_pgm_info));
 115         pgm_info->code = vcpu->arch.sie_block->iprcc;
 116
 117         switch (vcpu->arch.sie_block->iprcc & ~PGM_PER) {
 118         case PGM_AFX_TRANSLATION:
 119         case PGM_ASX_TRANSLATION:
 120         case PGM_EX_TRANSLATION:
 121         case PGM_LFX_TRANSLATION:
 122         case PGM_LSTE_SEQUENCE:
 123         case PGM_LSX_TRANSLATION:
 124         case PGM_LX_TRANSLATION:
 125         case PGM_PRIMARY_AUTHORITY:
 126         case PGM_SECONDARY_AUTHORITY:
 127         case PGM_SPACE_SWITCH:
 128                 pgm_info->trans_exc_code = vcpu->arch.sie_block->tecmc;
 129                 break;
 130         case PGM_ALEN_TRANSLATION:
 131         case PGM_ALE_SEQUENCE:
 132         case PGM_ASTE_INSTANCE:
 133         case PGM_ASTE_SEQUENCE:
 134         case PGM_ASTE_VALIDITY:
 135         case PGM_EXTENDED_AUTHORITY:
 136                 pgm_info->exc_access_id = vcpu->arch.sie_block->eai;
 137                 break;
 138         case PGM_ASCE_TYPE:
 139         case PGM_PAGE_TRANSLATION:
 140         case PGM_REGION_FIRST_TRANS:
 141         case PGM_REGION_SECOND_TRANS:
 142         case PGM_REGION_THIRD_TRANS:
 143         case PGM_SEGMENT_TRANSLATION:
 144                 pgm_info->trans_exc_code = vcpu->arch.sie_block->tecmc;
 145                 pgm_info->exc_access_id  = vcpu->arch.sie_block->eai;
 146                 pgm_info->op_access_id  = vcpu->arch.sie_block->oai;
 147                 break;
 148         case PGM_MONITOR:
 149                 pgm_info->mon_class_nr = vcpu->arch.sie_block->mcn;
 150                 pgm_info->mon_code = vcpu->arch.sie_block->tecmc;
 151                 break;
 152         case PGM_DATA:
 153                 pgm_info->data_exc_code = vcpu->arch.sie_block->dxc;
 154                 break;
 155         case PGM_PROTECTION:
 156                 pgm_info->trans_exc_code = vcpu->arch.sie_block->tecmc;
 157                 pgm_info->exc_access_id  = vcpu->arch.sie_block->eai;
 158                 break;
 159         default:
 160                 break;
 161         }
 162
 163         if (vcpu->arch.sie_block->iprcc & PGM_PER) {
 164                 pgm_info->per_code = vcpu->arch.sie_block->perc;
 165                 pgm_info->per_atmid = vcpu->arch.sie_block->peratmid;
 166                 pgm_info->per_address = vcpu->arch.sie_block->peraddr;
 167                 pgm_info->per_access_id = vcpu->arch.sie_block->peraid;
 168         }
 169 }
 170
 171 /*
 172  * restore ITDB to program-interruption TDB in guest lowcore
 173  * and set TX abort indication if required
 174 */
 175 static int handle_itdb(struct kvm_vcpu *vcpu)
 176 {
 177         struct kvm_s390_itdb *itdb;
 178         int rc;
 179
 180         if (!IS_TE_ENABLED(vcpu) || !IS_ITDB_VALID(vcpu))
 181                 return 0;
 182         if (current->thread.per_flags & PER_FLAG_NO_TE)
 183                 return 0;
 184         itdb = (struct kvm_s390_itdb *)vcpu->arch.sie_block->itdba;
 185         rc = write_guest_lc(vcpu, __LC_PGM_TDB, itdb, sizeof(*itdb));
 186         if (rc)
 187                 return rc;
 188         memset(itdb, 0, sizeof(*itdb));
 189
 190         return 0;
 191 }
 192
 193 #define per_event(vcpu) (vcpu->arch.sie_block->iprcc & PGM_PER)
 194
 195 static int handle_prog(struct kvm_vcpu *vcpu)
 196 {
 197         struct kvm_s390_pgm_info pgm_info;
 198         psw_t psw;
 199         int rc;
 200
 201         vcpu->stat.exit_program_interruption++;
 202
 203         if (guestdbg_enabled(vcpu) && per_event(vcpu)) {
 204                 kvm_s390_handle_per_event(vcpu);
 205                 /* the interrupt might have been filtered out completely */
 206                 if (vcpu->arch.sie_block->iprcc == 0)
 207                         return 0;
 208         }
 209
 210         trace_kvm_s390_intercept_prog(vcpu, vcpu->arch.sie_block->iprcc);
 211         if (vcpu->arch.sie_block->iprcc == PGM_SPECIFICATION) {
 212                 rc = read_guest_lc(vcpu, __LC_PGM_NEW_PSW, &psw, sizeof(psw_t));
 213                 if (rc)
 214                         return rc;
 215                 /* Avoid endless loops of specification exceptions */
 216                 if (!is_valid_psw(&psw))
 217                         return -EOPNOTSUPP;
 218         }
 219         rc = handle_itdb(vcpu);
 220         if (rc)
 221                 return rc;
 222
 223         __extract_prog_irq(vcpu, &pgm_info);
 224         return kvm_s390_inject_prog_irq(vcpu, &pgm_info);
 225 }
 226
 227 static int handle_instruction_and_prog(struct kvm_vcpu *vcpu)
 228 {
 229         int rc, rc2;
 230
 231         vcpu->stat.exit_instr_and_program++;
 232         rc = handle_instruction(vcpu);
 233         rc2 = handle_prog(vcpu);
 234
 235         if (rc == -EOPNOTSUPP)
 236                 vcpu->arch.sie_block->icptcode = 0x04;
 237         if (rc)
 238                 return rc;
 239         return rc2;
 240 }
 241
 242 /**
 243  * handle_external_interrupt - used for external interruption interceptions
 244  *
 245  * This interception only occurs if the CPUSTAT_EXT_INT bit was set, or if
 246  * the new PSW does not have external interrupts disabled. In the first case,
 247  * we've got to deliver the interrupt manually, and in the second case, we
 248  * drop to userspace to handle the situation there.
 249  */
 250 static int handle_external_interrupt(struct kvm_vcpu *vcpu)
 251 {
 252         u16 eic = vcpu->arch.sie_block->eic;
 253         struct kvm_s390_interrupt irq;
 254         psw_t newpsw;
 255         int rc;
 256
 257         vcpu->stat.exit_external_interrupt++;
 258
 259         rc = read_guest_lc(vcpu, __LC_EXT_NEW_PSW, &newpsw, sizeof(psw_t));
 260         if (rc)
 261                 return rc;
 262         /* We can not handle clock comparator or timer interrupt with bad PSW */
 263         if ((eic == EXT_IRQ_CLK_COMP || eic == EXT_IRQ_CPU_TIMER) &&
 264             (newpsw.mask & PSW_MASK_EXT))
 265                 return -EOPNOTSUPP;
 266
 267         switch (eic) {
 268         case EXT_IRQ_CLK_COMP:
 269                 irq.type = KVM_S390_INT_CLOCK_COMP;
 270                 break;
 271         case EXT_IRQ_CPU_TIMER:
 272                 irq.type = KVM_S390_INT_CPU_TIMER;
 273                 break;
 274         case EXT_IRQ_EXTERNAL_CALL:
 275                 if (kvm_s390_si_ext_call_pending(vcpu))
 276                         return 0;
 277                 irq.type = KVM_S390_INT_EXTERNAL_CALL;
 278                 irq.parm = vcpu->arch.sie_block->extcpuaddr;
 279                 break;
 280         default:
 281                 return -EOPNOTSUPP;
 282         }
 283
 284         return kvm_s390_inject_vcpu(vcpu, &irq);
 285 }
 286
 287 /**
 288  * Handle MOVE PAGE partial execution interception.
 289  *
 290  * This interception can only happen for guests with DAT disabled and
 291  * addresses that are currently not mapped in the host. Thus we try to
 292  * set up the mappings for the corresponding user pages here (or throw
 293  * addressing exceptions in case of illegal guest addresses).
 294  */
 295 static int handle_mvpg_pei(struct kvm_vcpu *vcpu)
 296 {
 297         psw_t *psw = &vcpu->arch.sie_block->gpsw;
 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         srcaddr = kvm_s390_real_to_abs(vcpu, vcpu->run->s.regs.gprs[reg2]);
 305         if (kvm_is_error_gpa(vcpu->kvm, srcaddr))
 306                 return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
 307         rc = kvm_arch_fault_in_page(vcpu, srcaddr, 0);
 308         if (rc != 0)
 309                 return rc;
 310
 311         /* Make sure that the destination is paged-in */
 312         dstaddr = kvm_s390_real_to_abs(vcpu, vcpu->run->s.regs.gprs[reg1]);
 313         if (kvm_is_error_gpa(vcpu->kvm, dstaddr))
 314                 return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
 315         rc = kvm_arch_fault_in_page(vcpu, dstaddr, 1);
 316         if (rc != 0)
 317                 return rc;
 318
 319         psw->addr = __rewind_psw(*psw, 4);
 320
 321         return 0;
 322 }
 323
 324 static int handle_partial_execution(struct kvm_vcpu *vcpu)
 325 {
 326         if (vcpu->arch.sie_block->ipa == 0xb254)        /* MVPG */
 327                 return handle_mvpg_pei(vcpu);
 328         if (vcpu->arch.sie_block->ipa >> 8 == 0xae)     /* SIGP */
 329                 return kvm_s390_handle_sigp_pei(vcpu);
 330
 331         return -EOPNOTSUPP;
 332 }
 333
 334 static const intercept_handler_t intercept_funcs[] = {
 335         [0x00 >> 2] = handle_noop,
 336         [0x04 >> 2] = handle_instruction,
 337         [0x08 >> 2] = handle_prog,
 338         [0x0C >> 2] = handle_instruction_and_prog,
 339         [0x10 >> 2] = handle_noop,
 340         [0x14 >> 2] = handle_external_interrupt,
 341         [0x18 >> 2] = handle_noop,
 342         [0x1C >> 2] = kvm_s390_handle_wait,
 343         [0x20 >> 2] = handle_validity,
 344         [0x28 >> 2] = handle_stop,
 345         [0x38 >> 2] = handle_partial_execution,
 346 };
 347
 348 int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
 349 {
 350         intercept_handler_t func;
 351         u8 code = vcpu->arch.sie_block->icptcode;
 352
 353         if (code & 3 || (code >> 2) >= ARRAY_SIZE(intercept_funcs))
 354                 return -EOPNOTSUPP;
 355         func = intercept_funcs[code >> 2];
 356         if (func)
 357                 return func(vcpu);
 358         return -EOPNOTSUPP;
 359 }