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         u64 useraddr;
  30         int reg, rc;
  31
  32         vcpu->stat.instruction_lctlg++;
  33
  34         useraddr = kvm_s390_get_base_disp_rsy(vcpu);
  35
  36         if (useraddr & 7)
  37                 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
  38
  39         reg = reg1;
  40
  41         VCPU_EVENT(vcpu, 5, "lctlg r1:%x, r3:%x, addr:%llx", reg1, reg3,
  42                    useraddr);
  43         trace_kvm_s390_handle_lctl(vcpu, 1, reg1, reg3, useraddr);
  44
  45         do {
  46                 rc = get_guest_u64(vcpu, useraddr,
  47                                    &vcpu->arch.sie_block->gcr[reg]);
  48                 if (rc == -EFAULT) {
  49                         kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
  50                         break;
  51                 }
  52                 useraddr += 8;
  53                 if (reg == reg3)
  54                         break;
  55                 reg = (reg + 1) % 16;
  56         } while (1);
  57         return 0;
  58 }
  59
  60 static int handle_lctl(struct kvm_vcpu *vcpu)
  61 {
  62         int reg1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
  63         int reg3 = vcpu->arch.sie_block->ipa & 0x000f;
  64         u64 useraddr;
  65         u32 val = 0;
  66         int reg, rc;
  67
  68         vcpu->stat.instruction_lctl++;
  69
  70         useraddr = kvm_s390_get_base_disp_rs(vcpu);
  71
  72         if (useraddr & 3)
  73                 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
  74
  75         VCPU_EVENT(vcpu, 5, "lctl r1:%x, r3:%x, addr:%llx", reg1, reg3,
  76                    useraddr);
  77         trace_kvm_s390_handle_lctl(vcpu, 0, reg1, reg3, useraddr);
  78
  79         reg = reg1;
  80         do {
  81                 rc = get_guest_u32(vcpu, useraddr, &val);
  82                 if (rc == -EFAULT) {
  83                         kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
  84                         break;
  85                 }
  86                 vcpu->arch.sie_block->gcr[reg] &= 0xffffffff00000000ul;
  87                 vcpu->arch.sie_block->gcr[reg] |= val;
  88                 useraddr += 4;
  89                 if (reg == reg3)
  90                         break;
  91                 reg = (reg + 1) % 16;
  92         } while (1);
  93         return 0;
  94 }
  95
  96 static const intercept_handler_t eb_handlers[256] = {
  97         [0x2f] = handle_lctlg,
  98         [0x8a] = kvm_s390_handle_priv_eb,
  99 };
 100
 101 static int handle_eb(struct kvm_vcpu *vcpu)
 102 {
 103         intercept_handler_t handler;
 104
 105         handler = eb_handlers[vcpu->arch.sie_block->ipb & 0xff];
 106         if (handler)
 107                 return handler(vcpu);
 108         return -EOPNOTSUPP;
 109 }
 110
 111 static const intercept_handler_t instruction_handlers[256] = {
 112         [0x01] = kvm_s390_handle_01,
 113         [0x82] = kvm_s390_handle_lpsw,
 114         [0x83] = kvm_s390_handle_diag,
 115         [0xae] = kvm_s390_handle_sigp,
 116         [0xb2] = kvm_s390_handle_b2,
 117         [0xb7] = handle_lctl,
 118         [0xb9] = kvm_s390_handle_b9,
 119         [0xe5] = kvm_s390_handle_e5,
 120         [0xeb] = handle_eb,
 121 };
 122
 123 static int handle_noop(struct kvm_vcpu *vcpu)
 124 {
 125         switch (vcpu->arch.sie_block->icptcode) {
 126         case 0x0:
 127                 vcpu->stat.exit_null++;
 128                 break;
 129         case 0x10:
 130                 vcpu->stat.exit_external_request++;
 131                 break;
 132         case 0x14:
 133                 vcpu->stat.exit_external_interrupt++;
 134                 break;
 135         default:
 136                 break; /* nothing */
 137         }
 138         return 0;
 139 }
 140
 141 static int handle_stop(struct kvm_vcpu *vcpu)
 142 {
 143         int rc = 0;
 144
 145         vcpu->stat.exit_stop_request++;
 146         spin_lock_bh(&vcpu->arch.local_int.lock);
 147
 148         trace_kvm_s390_stop_request(vcpu->arch.local_int.action_bits);
 149
 150         if (vcpu->arch.local_int.action_bits & ACTION_RELOADVCPU_ON_STOP) {
 151                 vcpu->arch.local_int.action_bits &= ~ACTION_RELOADVCPU_ON_STOP;
 152                 rc = SIE_INTERCEPT_RERUNVCPU;
 153                 vcpu->run->exit_reason = KVM_EXIT_INTR;
 154         }
 155
 156         if (vcpu->arch.local_int.action_bits & ACTION_STOP_ON_STOP) {
 157                 atomic_set_mask(CPUSTAT_STOPPED,
 158                                 &vcpu->arch.sie_block->cpuflags);
 159                 vcpu->arch.local_int.action_bits &= ~ACTION_STOP_ON_STOP;
 160                 VCPU_EVENT(vcpu, 3, "%s", "cpu stopped");
 161                 rc = -EOPNOTSUPP;
 162         }
 163
 164         if (vcpu->arch.local_int.action_bits & ACTION_STORE_ON_STOP) {
 165                 vcpu->arch.local_int.action_bits &= ~ACTION_STORE_ON_STOP;
 166                 /* store status must be called unlocked. Since local_int.lock
 167                  * only protects local_int.* and not guest memory we can give
 168                  * up the lock here */
 169                 spin_unlock_bh(&vcpu->arch.local_int.lock);
 170                 rc = kvm_s390_vcpu_store_status(vcpu,
 171                                                 KVM_S390_STORE_STATUS_NOADDR);
 172                 if (rc >= 0)
 173                         rc = -EOPNOTSUPP;
 174         } else
 175                 spin_unlock_bh(&vcpu->arch.local_int.lock);
 176         return rc;
 177 }
 178
 179 static int handle_validity(struct kvm_vcpu *vcpu)
 180 {
 181         unsigned long vmaddr;
 182         int viwhy = vcpu->arch.sie_block->ipb >> 16;
 183         int rc;
 184
 185         vcpu->stat.exit_validity++;
 186         trace_kvm_s390_intercept_validity(vcpu, viwhy);
 187         if (viwhy == 0x37) {
 188                 vmaddr = gmap_fault(vcpu->arch.sie_block->prefix,
 189                                     vcpu->arch.gmap);
 190                 if (IS_ERR_VALUE(vmaddr)) {
 191                         rc = -EOPNOTSUPP;
 192                         goto out;
 193                 }
 194                 rc = fault_in_pages_writeable((char __user *) vmaddr,
 195                          PAGE_SIZE);
 196                 if (rc) {
 197                         /* user will receive sigsegv, exit to user */
 198                         rc = -EOPNOTSUPP;
 199                         goto out;
 200                 }
 201                 vmaddr = gmap_fault(vcpu->arch.sie_block->prefix + PAGE_SIZE,
 202                                     vcpu->arch.gmap);
 203                 if (IS_ERR_VALUE(vmaddr)) {
 204                         rc = -EOPNOTSUPP;
 205                         goto out;
 206                 }
 207                 rc = fault_in_pages_writeable((char __user *) vmaddr,
 208                          PAGE_SIZE);
 209                 if (rc) {
 210                         /* user will receive sigsegv, exit to user */
 211                         rc = -EOPNOTSUPP;
 212                         goto out;
 213                 }
 214         } else
 215                 rc = -EOPNOTSUPP;
 216
 217 out:
 218         if (rc)
 219                 VCPU_EVENT(vcpu, 2, "unhandled validity intercept code %d",
 220                            viwhy);
 221         return rc;
 222 }
 223
 224 static int handle_instruction(struct kvm_vcpu *vcpu)
 225 {
 226         intercept_handler_t handler;
 227
 228         vcpu->stat.exit_instruction++;
 229         trace_kvm_s390_intercept_instruction(vcpu,
 230                                              vcpu->arch.sie_block->ipa,
 231                                              vcpu->arch.sie_block->ipb);
 232         handler = instruction_handlers[vcpu->arch.sie_block->ipa >> 8];
 233         if (handler)
 234                 return handler(vcpu);
 235         return -EOPNOTSUPP;
 236 }
 237
 238 static int handle_prog(struct kvm_vcpu *vcpu)
 239 {
 240         vcpu->stat.exit_program_interruption++;
 241         trace_kvm_s390_intercept_prog(vcpu, vcpu->arch.sie_block->iprcc);
 242         return kvm_s390_inject_program_int(vcpu, vcpu->arch.sie_block->iprcc);
 243 }
 244
 245 static int handle_instruction_and_prog(struct kvm_vcpu *vcpu)
 246 {
 247         int rc, rc2;
 248
 249         vcpu->stat.exit_instr_and_program++;
 250         rc = handle_instruction(vcpu);
 251         rc2 = handle_prog(vcpu);
 252
 253         if (rc == -EOPNOTSUPP)
 254                 vcpu->arch.sie_block->icptcode = 0x04;
 255         if (rc)
 256                 return rc;
 257         return rc2;
 258 }
 259
 260 static const intercept_handler_t intercept_funcs[] = {
 261         [0x00 >> 2] = handle_noop,
 262         [0x04 >> 2] = handle_instruction,
 263         [0x08 >> 2] = handle_prog,
 264         [0x0C >> 2] = handle_instruction_and_prog,
 265         [0x10 >> 2] = handle_noop,
 266         [0x14 >> 2] = handle_noop,
 267         [0x1C >> 2] = kvm_s390_handle_wait,
 268         [0x20 >> 2] = handle_validity,
 269         [0x28 >> 2] = handle_stop,
 270 };
 271
 272 int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
 273 {
 274         intercept_handler_t func;
 275         u8 code = vcpu->arch.sie_block->icptcode;
 276
 277         if (code & 3 || (code >> 2) >= ARRAY_SIZE(intercept_funcs))
 278                 return -EOPNOTSUPP;
 279         func = intercept_funcs[code >> 2];
 280         if (func)
 281                 return func(vcpu);
 282         return -EOPNOTSUPP;
 283 }