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         unsigned int action_bits;
  60
  61         vcpu->stat.exit_stop_request++;
  62         trace_kvm_s390_stop_request(vcpu->arch.local_int.action_bits);
  63
  64         action_bits = vcpu->arch.local_int.action_bits;
  65
  66         if (!(action_bits & ACTION_STOP_ON_STOP))
  67                 return 0;
  68
  69         if (action_bits & ACTION_STORE_ON_STOP) {
  70                 rc = kvm_s390_vcpu_store_status(vcpu,
  71                                                 KVM_S390_STORE_STATUS_NOADDR);
  72                 if (rc)
  73                         return rc;
  74         }
  75
  76         if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm))
  77                 kvm_s390_vcpu_stop(vcpu);
  78         return -EOPNOTSUPP;
  79 }
  80
  81 static int handle_validity(struct kvm_vcpu *vcpu)
  82 {
  83         int viwhy = vcpu->arch.sie_block->ipb >> 16;
  84
  85         vcpu->stat.exit_validity++;
  86         trace_kvm_s390_intercept_validity(vcpu, viwhy);
  87         WARN_ONCE(true, "kvm: unhandled validity intercept 0x%x\n", viwhy);
  88         return -EOPNOTSUPP;
  89 }
  90
  91 static int handle_instruction(struct kvm_vcpu *vcpu)
  92 {
  93         intercept_handler_t handler;
  94
  95         vcpu->stat.exit_instruction++;
  96         trace_kvm_s390_intercept_instruction(vcpu,
  97                                              vcpu->arch.sie_block->ipa,
  98                                              vcpu->arch.sie_block->ipb);
  99         handler = instruction_handlers[vcpu->arch.sie_block->ipa >> 8];
 100         if (handler)
 101                 return handler(vcpu);
 102         return -EOPNOTSUPP;
 103 }
 104
 105 static void __extract_prog_irq(struct kvm_vcpu *vcpu,
 106                                struct kvm_s390_pgm_info *pgm_info)
 107 {
 108         memset(pgm_info, 0, sizeof(struct kvm_s390_pgm_info));
 109         pgm_info->code = vcpu->arch.sie_block->iprcc;
 110
 111         switch (vcpu->arch.sie_block->iprcc & ~PGM_PER) {
 112         case PGM_AFX_TRANSLATION:
 113         case PGM_ASX_TRANSLATION:
 114         case PGM_EX_TRANSLATION:
 115         case PGM_LFX_TRANSLATION:
 116         case PGM_LSTE_SEQUENCE:
 117         case PGM_LSX_TRANSLATION:
 118         case PGM_LX_TRANSLATION:
 119         case PGM_PRIMARY_AUTHORITY:
 120         case PGM_SECONDARY_AUTHORITY:
 121         case PGM_SPACE_SWITCH:
 122                 pgm_info->trans_exc_code = vcpu->arch.sie_block->tecmc;
 123                 break;
 124         case PGM_ALEN_TRANSLATION:
 125         case PGM_ALE_SEQUENCE:
 126         case PGM_ASTE_INSTANCE:
 127         case PGM_ASTE_SEQUENCE:
 128         case PGM_ASTE_VALIDITY:
 129         case PGM_EXTENDED_AUTHORITY:
 130                 pgm_info->exc_access_id = vcpu->arch.sie_block->eai;
 131                 break;
 132         case PGM_ASCE_TYPE:
 133         case PGM_PAGE_TRANSLATION:
 134         case PGM_REGION_FIRST_TRANS:
 135         case PGM_REGION_SECOND_TRANS:
 136         case PGM_REGION_THIRD_TRANS:
 137         case PGM_SEGMENT_TRANSLATION:
 138                 pgm_info->trans_exc_code = vcpu->arch.sie_block->tecmc;
 139                 pgm_info->exc_access_id  = vcpu->arch.sie_block->eai;
 140                 pgm_info->op_access_id  = vcpu->arch.sie_block->oai;
 141                 break;
 142         case PGM_MONITOR:
 143                 pgm_info->mon_class_nr = vcpu->arch.sie_block->mcn;
 144                 pgm_info->mon_code = vcpu->arch.sie_block->tecmc;
 145                 break;
 146         case PGM_DATA:
 147                 pgm_info->data_exc_code = vcpu->arch.sie_block->dxc;
 148                 break;
 149         case PGM_PROTECTION:
 150                 pgm_info->trans_exc_code = vcpu->arch.sie_block->tecmc;
 151                 pgm_info->exc_access_id  = vcpu->arch.sie_block->eai;
 152                 break;
 153         default:
 154                 break;
 155         }
 156
 157         if (vcpu->arch.sie_block->iprcc & PGM_PER) {
 158                 pgm_info->per_code = vcpu->arch.sie_block->perc;
 159                 pgm_info->per_atmid = vcpu->arch.sie_block->peratmid;
 160                 pgm_info->per_address = vcpu->arch.sie_block->peraddr;
 161                 pgm_info->per_access_id = vcpu->arch.sie_block->peraid;
 162         }
 163 }
 164
 165 /*
 166  * restore ITDB to program-interruption TDB in guest lowcore
 167  * and set TX abort indication if required
 168 */
 169 static int handle_itdb(struct kvm_vcpu *vcpu)
 170 {
 171         struct kvm_s390_itdb *itdb;
 172         int rc;
 173
 174         if (!IS_TE_ENABLED(vcpu) || !IS_ITDB_VALID(vcpu))
 175                 return 0;
 176         if (current->thread.per_flags & PER_FLAG_NO_TE)
 177                 return 0;
 178         itdb = (struct kvm_s390_itdb *)vcpu->arch.sie_block->itdba;
 179         rc = write_guest_lc(vcpu, __LC_PGM_TDB, itdb, sizeof(*itdb));
 180         if (rc)
 181                 return rc;
 182         memset(itdb, 0, sizeof(*itdb));
 183
 184         return 0;
 185 }
 186
 187 #define per_event(vcpu) (vcpu->arch.sie_block->iprcc & PGM_PER)
 188
 189 static int handle_prog(struct kvm_vcpu *vcpu)
 190 {
 191         struct kvm_s390_pgm_info pgm_info;
 192         psw_t psw;
 193         int rc;
 194
 195         vcpu->stat.exit_program_interruption++;
 196
 197         if (guestdbg_enabled(vcpu) && per_event(vcpu)) {
 198                 kvm_s390_handle_per_event(vcpu);
 199                 /* the interrupt might have been filtered out completely */
 200                 if (vcpu->arch.sie_block->iprcc == 0)
 201                         return 0;
 202         }
 203
 204         trace_kvm_s390_intercept_prog(vcpu, vcpu->arch.sie_block->iprcc);
 205         if (vcpu->arch.sie_block->iprcc == PGM_SPECIFICATION) {
 206                 rc = read_guest_lc(vcpu, __LC_PGM_NEW_PSW, &psw, sizeof(psw_t));
 207                 if (rc)
 208                         return rc;
 209                 /* Avoid endless loops of specification exceptions */
 210                 if (!is_valid_psw(&psw))
 211                         return -EOPNOTSUPP;
 212         }
 213         rc = handle_itdb(vcpu);
 214         if (rc)
 215                 return rc;
 216
 217         __extract_prog_irq(vcpu, &pgm_info);
 218         return kvm_s390_inject_prog_irq(vcpu, &pgm_info);
 219 }
 220
 221 static int handle_instruction_and_prog(struct kvm_vcpu *vcpu)
 222 {
 223         int rc, rc2;
 224
 225         vcpu->stat.exit_instr_and_program++;
 226         rc = handle_instruction(vcpu);
 227         rc2 = handle_prog(vcpu);
 228
 229         if (rc == -EOPNOTSUPP)
 230                 vcpu->arch.sie_block->icptcode = 0x04;
 231         if (rc)
 232                 return rc;
 233         return rc2;
 234 }
 235
 236 /**
 237  * handle_external_interrupt - used for external interruption interceptions
 238  *
 239  * This interception only occurs if the CPUSTAT_EXT_INT bit was set, or if
 240  * the new PSW does not have external interrupts disabled. In the first case,
 241  * we've got to deliver the interrupt manually, and in the second case, we
 242  * drop to userspace to handle the situation there.
 243  */
 244 static int handle_external_interrupt(struct kvm_vcpu *vcpu)
 245 {
 246         u16 eic = vcpu->arch.sie_block->eic;
 247         struct kvm_s390_interrupt irq;
 248         psw_t newpsw;
 249         int rc;
 250
 251         vcpu->stat.exit_external_interrupt++;
 252
 253         rc = read_guest_lc(vcpu, __LC_EXT_NEW_PSW, &newpsw, sizeof(psw_t));
 254         if (rc)
 255                 return rc;
 256         /* We can not handle clock comparator or timer interrupt with bad PSW */
 257         if ((eic == EXT_IRQ_CLK_COMP || eic == EXT_IRQ_CPU_TIMER) &&
 258             (newpsw.mask & PSW_MASK_EXT))
 259                 return -EOPNOTSUPP;
 260
 261         switch (eic) {
 262         case EXT_IRQ_CLK_COMP:
 263                 irq.type = KVM_S390_INT_CLOCK_COMP;
 264                 break;
 265         case EXT_IRQ_CPU_TIMER:
 266                 irq.type = KVM_S390_INT_CPU_TIMER;
 267                 break;
 268         case EXT_IRQ_EXTERNAL_CALL:
 269                 if (kvm_s390_si_ext_call_pending(vcpu))
 270                         return 0;
 271                 irq.type = KVM_S390_INT_EXTERNAL_CALL;
 272                 irq.parm = vcpu->arch.sie_block->extcpuaddr;
 273                 break;
 274         default:
 275                 return -EOPNOTSUPP;
 276         }
 277
 278         return kvm_s390_inject_vcpu(vcpu, &irq);
 279 }
 280
 281 /**
 282  * Handle MOVE PAGE partial execution interception.
 283  *
 284  * This interception can only happen for guests with DAT disabled and
 285  * addresses that are currently not mapped in the host. Thus we try to
 286  * set up the mappings for the corresponding user pages here (or throw
 287  * addressing exceptions in case of illegal guest addresses).
 288  */
 289 static int handle_mvpg_pei(struct kvm_vcpu *vcpu)
 290 {
 291         psw_t *psw = &vcpu->arch.sie_block->gpsw;
 292         unsigned long srcaddr, dstaddr;
 293         int reg1, reg2, rc;
 294
 295         kvm_s390_get_regs_rre(vcpu, &reg1, &reg2);
 296
 297         /* Make sure that the source is paged-in */
 298         srcaddr = kvm_s390_real_to_abs(vcpu, vcpu->run->s.regs.gprs[reg2]);
 299         if (kvm_is_error_gpa(vcpu->kvm, srcaddr))
 300                 return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
 301         rc = kvm_arch_fault_in_page(vcpu, srcaddr, 0);
 302         if (rc != 0)
 303                 return rc;
 304
 305         /* Make sure that the destination is paged-in */
 306         dstaddr = kvm_s390_real_to_abs(vcpu, vcpu->run->s.regs.gprs[reg1]);
 307         if (kvm_is_error_gpa(vcpu->kvm, dstaddr))
 308                 return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
 309         rc = kvm_arch_fault_in_page(vcpu, dstaddr, 1);
 310         if (rc != 0)
 311                 return rc;
 312
 313         psw->addr = __rewind_psw(*psw, 4);
 314
 315         return 0;
 316 }
 317
 318 static int handle_partial_execution(struct kvm_vcpu *vcpu)
 319 {
 320         if (vcpu->arch.sie_block->ipa == 0xb254)        /* MVPG */
 321                 return handle_mvpg_pei(vcpu);
 322         if (vcpu->arch.sie_block->ipa >> 8 == 0xae)     /* SIGP */
 323                 return kvm_s390_handle_sigp_pei(vcpu);
 324
 325         return -EOPNOTSUPP;
 326 }
 327
 328 static const intercept_handler_t intercept_funcs[] = {
 329         [0x00 >> 2] = handle_noop,
 330         [0x04 >> 2] = handle_instruction,
 331         [0x08 >> 2] = handle_prog,
 332         [0x0C >> 2] = handle_instruction_and_prog,
 333         [0x10 >> 2] = handle_noop,
 334         [0x14 >> 2] = handle_external_interrupt,
 335         [0x18 >> 2] = handle_noop,
 336         [0x1C >> 2] = kvm_s390_handle_wait,
 337         [0x20 >> 2] = handle_validity,
 338         [0x28 >> 2] = handle_stop,
 339         [0x38 >> 2] = handle_partial_execution,
 340 };
 341
 342 int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
 343 {
 344         intercept_handler_t func;
 345         u8 code = vcpu->arch.sie_block->icptcode;
 346
 347         if (code & 3 || (code >> 2) >= ARRAY_SIZE(intercept_funcs))
 348                 return -EOPNOTSUPP;
 349         func = intercept_funcs[code >> 2];
 350         if (func)
 351                 return func(vcpu);
 352         return -EOPNOTSUPP;
 353 }