arch/s390/kvm/intercept.c

   1 /*
   2  * in-kernel handling for sie intercepts
   3  *
   4  * Copyright IBM Corp. 2008, 2009
   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
  20 #include "kvm-s390.h"
  21 #include "gaccess.h"
  22 #include "trace.h"
  23 #include "trace-s390.h"
  24
  25 static int handle_lctlg(struct kvm_vcpu *vcpu)
  26 {
  27         int reg1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
  28         int reg3 = vcpu->arch.sie_block->ipa & 0x000f;
  29         int base2 = vcpu->arch.sie_block->ipb >> 28;
  30         int disp2 = ((vcpu->arch.sie_block->ipb & 0x0fff0000) >> 16) +
  31                         ((vcpu->arch.sie_block->ipb & 0xff00) << 4);
  32         u64 useraddr;
  33         int reg, rc;
  34
  35         vcpu->stat.instruction_lctlg++;
  36         if ((vcpu->arch.sie_block->ipb & 0xff) != 0x2f)
  37                 return -EOPNOTSUPP;
  38
  39         useraddr = disp2;
  40         if (base2)
  41                 useraddr += vcpu->run->s.regs.gprs[base2];
  42
  43         if (useraddr & 7)
  44                 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
  45
  46         reg = reg1;
  47
  48         VCPU_EVENT(vcpu, 5, "lctlg r1:%x, r3:%x,b2:%x,d2:%x", reg1, reg3, base2,
  49                    disp2);
  50         trace_kvm_s390_handle_lctl(vcpu, 1, reg1, reg3, useraddr);
  51
  52         do {
  53                 rc = get_guest_u64(vcpu, useraddr,
  54                                    &vcpu->arch.sie_block->gcr[reg]);
  55                 if (rc == -EFAULT) {
  56                         kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
  57                         break;
  58                 }
  59                 useraddr += 8;
  60                 if (reg == reg3)
  61                         break;
  62                 reg = (reg + 1) % 16;
  63         } while (1);
  64         return 0;
  65 }
  66
  67 static int handle_lctl(struct kvm_vcpu *vcpu)
  68 {
  69         int reg1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
  70         int reg3 = vcpu->arch.sie_block->ipa & 0x000f;
  71         int base2 = vcpu->arch.sie_block->ipb >> 28;
  72         int disp2 = ((vcpu->arch.sie_block->ipb & 0x0fff0000) >> 16);
  73         u64 useraddr;
  74         u32 val = 0;
  75         int reg, rc;
  76
  77         vcpu->stat.instruction_lctl++;
  78
  79         useraddr = disp2;
  80         if (base2)
  81                 useraddr += vcpu->run->s.regs.gprs[base2];
  82
  83         if (useraddr & 3)
  84                 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
  85
  86         VCPU_EVENT(vcpu, 5, "lctl r1:%x, r3:%x,b2:%x,d2:%x", reg1, reg3, base2,
  87                    disp2);
  88         trace_kvm_s390_handle_lctl(vcpu, 0, reg1, reg3, useraddr);
  89
  90         reg = reg1;
  91         do {
  92                 rc = get_guest_u32(vcpu, useraddr, &val);
  93                 if (rc == -EFAULT) {
  94                         kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
  95                         break;
  96                 }
  97                 vcpu->arch.sie_block->gcr[reg] &= 0xffffffff00000000ul;
  98                 vcpu->arch.sie_block->gcr[reg] |= val;
  99                 useraddr += 4;
 100                 if (reg == reg3)
 101                         break;
 102                 reg = (reg + 1) % 16;
 103         } while (1);
 104         return 0;
 105 }
 106
 107 static intercept_handler_t instruction_handlers[256] = {
 108         [0x01] = kvm_s390_handle_01,
 109         [0x83] = kvm_s390_handle_diag,
 110         [0xae] = kvm_s390_handle_sigp,
 111         [0xb2] = kvm_s390_handle_b2,
 112         [0xb7] = handle_lctl,
 113         [0xe5] = kvm_s390_handle_e5,
 114         [0xeb] = handle_lctlg,
 115 };
 116
 117 static int handle_noop(struct kvm_vcpu *vcpu)
 118 {
 119         switch (vcpu->arch.sie_block->icptcode) {
 120         case 0x0:
 121                 vcpu->stat.exit_null++;
 122                 break;
 123         case 0x10:
 124                 vcpu->stat.exit_external_request++;
 125                 break;
 126         case 0x14:
 127                 vcpu->stat.exit_external_interrupt++;
 128                 break;
 129         default:
 130                 break; /* nothing */
 131         }
 132         return 0;
 133 }
 134
 135 static int handle_stop(struct kvm_vcpu *vcpu)
 136 {
 137         int rc = 0;
 138
 139         vcpu->stat.exit_stop_request++;
 140         spin_lock_bh(&vcpu->arch.local_int.lock);
 141
 142         trace_kvm_s390_stop_request(vcpu->arch.local_int.action_bits);
 143
 144         if (vcpu->arch.local_int.action_bits & ACTION_RELOADVCPU_ON_STOP) {
 145                 vcpu->arch.local_int.action_bits &= ~ACTION_RELOADVCPU_ON_STOP;
 146                 rc = SIE_INTERCEPT_RERUNVCPU;
 147                 vcpu->run->exit_reason = KVM_EXIT_INTR;
 148         }
 149
 150         if (vcpu->arch.local_int.action_bits & ACTION_STOP_ON_STOP) {
 151                 atomic_set_mask(CPUSTAT_STOPPED,
 152                                 &vcpu->arch.sie_block->cpuflags);
 153                 vcpu->arch.local_int.action_bits &= ~ACTION_STOP_ON_STOP;
 154                 VCPU_EVENT(vcpu, 3, "%s", "cpu stopped");
 155                 rc = -EOPNOTSUPP;
 156         }
 157
 158         if (vcpu->arch.local_int.action_bits & ACTION_STORE_ON_STOP) {
 159                 vcpu->arch.local_int.action_bits &= ~ACTION_STORE_ON_STOP;
 160                 /* store status must be called unlocked. Since local_int.lock
 161                  * only protects local_int.* and not guest memory we can give
 162                  * up the lock here */
 163                 spin_unlock_bh(&vcpu->arch.local_int.lock);
 164                 rc = kvm_s390_vcpu_store_status(vcpu,
 165                                                 KVM_S390_STORE_STATUS_NOADDR);
 166                 if (rc >= 0)
 167                         rc = -EOPNOTSUPP;
 168         } else
 169                 spin_unlock_bh(&vcpu->arch.local_int.lock);
 170         return rc;
 171 }
 172
 173 static int handle_validity(struct kvm_vcpu *vcpu)
 174 {
 175         unsigned long vmaddr;
 176         int viwhy = vcpu->arch.sie_block->ipb >> 16;
 177         int rc;
 178
 179         vcpu->stat.exit_validity++;
 180         trace_kvm_s390_intercept_validity(vcpu, viwhy);
 181         if (viwhy == 0x37) {
 182                 vmaddr = gmap_fault(vcpu->arch.sie_block->prefix,
 183                                     vcpu->arch.gmap);
 184                 if (IS_ERR_VALUE(vmaddr)) {
 185                         rc = -EOPNOTSUPP;
 186                         goto out;
 187                 }
 188                 rc = fault_in_pages_writeable((char __user *) vmaddr,
 189                          PAGE_SIZE);
 190                 if (rc) {
 191                         /* user will receive sigsegv, exit to user */
 192                         rc = -EOPNOTSUPP;
 193                         goto out;
 194                 }
 195                 vmaddr = gmap_fault(vcpu->arch.sie_block->prefix + PAGE_SIZE,
 196                                     vcpu->arch.gmap);
 197                 if (IS_ERR_VALUE(vmaddr)) {
 198                         rc = -EOPNOTSUPP;
 199                         goto out;
 200                 }
 201                 rc = fault_in_pages_writeable((char __user *) vmaddr,
 202                          PAGE_SIZE);
 203                 if (rc) {
 204                         /* user will receive sigsegv, exit to user */
 205                         rc = -EOPNOTSUPP;
 206                         goto out;
 207                 }
 208         } else
 209                 rc = -EOPNOTSUPP;
 210
 211 out:
 212         if (rc)
 213                 VCPU_EVENT(vcpu, 2, "unhandled validity intercept code %d",
 214                            viwhy);
 215         return rc;
 216 }
 217
 218 static int handle_instruction(struct kvm_vcpu *vcpu)
 219 {
 220         intercept_handler_t handler;
 221
 222         vcpu->stat.exit_instruction++;
 223         trace_kvm_s390_intercept_instruction(vcpu,
 224                                              vcpu->arch.sie_block->ipa,
 225                                              vcpu->arch.sie_block->ipb);
 226         handler = instruction_handlers[vcpu->arch.sie_block->ipa >> 8];
 227         if (handler)
 228                 return handler(vcpu);
 229         return -EOPNOTSUPP;
 230 }
 231
 232 static int handle_prog(struct kvm_vcpu *vcpu)
 233 {
 234         vcpu->stat.exit_program_interruption++;
 235         trace_kvm_s390_intercept_prog(vcpu, vcpu->arch.sie_block->iprcc);
 236         return kvm_s390_inject_program_int(vcpu, vcpu->arch.sie_block->iprcc);
 237 }
 238
 239 static int handle_instruction_and_prog(struct kvm_vcpu *vcpu)
 240 {
 241         int rc, rc2;
 242
 243         vcpu->stat.exit_instr_and_program++;
 244         rc = handle_instruction(vcpu);
 245         rc2 = handle_prog(vcpu);
 246
 247         if (rc == -EOPNOTSUPP)
 248                 vcpu->arch.sie_block->icptcode = 0x04;
 249         if (rc)
 250                 return rc;
 251         return rc2;
 252 }
 253
 254 static const intercept_handler_t intercept_funcs[] = {
 255         [0x00 >> 2] = handle_noop,
 256         [0x04 >> 2] = handle_instruction,
 257         [0x08 >> 2] = handle_prog,
 258         [0x0C >> 2] = handle_instruction_and_prog,
 259         [0x10 >> 2] = handle_noop,
 260         [0x14 >> 2] = handle_noop,
 261         [0x1C >> 2] = kvm_s390_handle_wait,
 262         [0x20 >> 2] = handle_validity,
 263         [0x28 >> 2] = handle_stop,
 264 };
 265
 266 int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
 267 {
 268         intercept_handler_t func;
 269         u8 code = vcpu->arch.sie_block->icptcode;
 270
 271         if (code & 3 || (code >> 2) >= ARRAY_SIZE(intercept_funcs))
 272                 return -EOPNOTSUPP;
 273         func = intercept_funcs[code >> 2];
 274         if (func)
 275                 return func(vcpu);
 276         return -EOPNOTSUPP;
 277 }