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