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(vcpu, vcpu->arch.sie_block->gcr[reg],
  47                                (u64 __user *) useraddr);
  48                 if (rc)
  49                         return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
  50                 useraddr += 8;
  51                 if (reg == reg3)
  52                         break;
  53                 reg = (reg + 1) % 16;
  54         } while (1);
  55         return 0;
  56 }
  57
  58 static int handle_lctl(struct kvm_vcpu *vcpu)
  59 {
  60         int reg1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
  61         int reg3 = vcpu->arch.sie_block->ipa & 0x000f;
  62         u64 useraddr;
  63         u32 val = 0;
  64         int reg, rc;
  65
  66         vcpu->stat.instruction_lctl++;
  67
  68         useraddr = kvm_s390_get_base_disp_rs(vcpu);
  69
  70         if (useraddr & 3)
  71                 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
  72
  73         VCPU_EVENT(vcpu, 5, "lctl r1:%x, r3:%x, addr:%llx", reg1, reg3,
  74                    useraddr);
  75         trace_kvm_s390_handle_lctl(vcpu, 0, reg1, reg3, useraddr);
  76
  77         reg = reg1;
  78         do {
  79                 rc = get_guest(vcpu, val, (u32 __user *) useraddr);
  80                 if (rc)
  81                         return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
  82                 vcpu->arch.sie_block->gcr[reg] &= 0xffffffff00000000ul;
  83                 vcpu->arch.sie_block->gcr[reg] |= val;
  84                 useraddr += 4;
  85                 if (reg == reg3)
  86                         break;
  87                 reg = (reg + 1) % 16;
  88         } while (1);
  89         return 0;
  90 }
  91
  92 static const intercept_handler_t eb_handlers[256] = {
  93         [0x2f] = handle_lctlg,
  94         [0x8a] = kvm_s390_handle_priv_eb,
  95 };
  96
  97 static int handle_eb(struct kvm_vcpu *vcpu)
  98 {
  99         intercept_handler_t handler;
 100
 101         handler = eb_handlers[vcpu->arch.sie_block->ipb & 0xff];
 102         if (handler)
 103                 return handler(vcpu);
 104         return -EOPNOTSUPP;
 105 }
 106
 107 static const intercept_handler_t instruction_handlers[256] = {
 108         [0x01] = kvm_s390_handle_01,
 109         [0x82] = kvm_s390_handle_lpsw,
 110         [0x83] = kvm_s390_handle_diag,
 111         [0xae] = kvm_s390_handle_sigp,
 112         [0xb2] = kvm_s390_handle_b2,
 113         [0xb7] = handle_lctl,
 114         [0xb9] = kvm_s390_handle_b9,
 115         [0xe5] = kvm_s390_handle_e5,
 116         [0xeb] = handle_eb,
 117 };
 118
 119 static int handle_noop(struct kvm_vcpu *vcpu)
 120 {
 121         switch (vcpu->arch.sie_block->icptcode) {
 122         case 0x0:
 123                 vcpu->stat.exit_null++;
 124                 break;
 125         case 0x10:
 126                 vcpu->stat.exit_external_request++;
 127                 break;
 128         case 0x14:
 129                 vcpu->stat.exit_external_interrupt++;
 130                 break;
 131         default:
 132                 break; /* nothing */
 133         }
 134         return 0;
 135 }
 136
 137 static int handle_stop(struct kvm_vcpu *vcpu)
 138 {
 139         int rc = 0;
 140
 141         vcpu->stat.exit_stop_request++;
 142         spin_lock_bh(&vcpu->arch.local_int.lock);
 143
 144         trace_kvm_s390_stop_request(vcpu->arch.local_int.action_bits);
 145
 146         if (vcpu->arch.local_int.action_bits & ACTION_RELOADVCPU_ON_STOP) {
 147                 vcpu->arch.local_int.action_bits &= ~ACTION_RELOADVCPU_ON_STOP;
 148                 rc = SIE_INTERCEPT_RERUNVCPU;
 149                 vcpu->run->exit_reason = KVM_EXIT_INTR;
 150         }
 151
 152         if (vcpu->arch.local_int.action_bits & ACTION_STOP_ON_STOP) {
 153                 atomic_set_mask(CPUSTAT_STOPPED,
 154                                 &vcpu->arch.sie_block->cpuflags);
 155                 vcpu->arch.local_int.action_bits &= ~ACTION_STOP_ON_STOP;
 156                 VCPU_EVENT(vcpu, 3, "%s", "cpu stopped");
 157                 rc = -EOPNOTSUPP;
 158         }
 159
 160         if (vcpu->arch.local_int.action_bits & ACTION_STORE_ON_STOP) {
 161                 vcpu->arch.local_int.action_bits &= ~ACTION_STORE_ON_STOP;
 162                 /* store status must be called unlocked. Since local_int.lock
 163                  * only protects local_int.* and not guest memory we can give
 164                  * up the lock here */
 165                 spin_unlock_bh(&vcpu->arch.local_int.lock);
 166                 rc = kvm_s390_vcpu_store_status(vcpu,
 167                                                 KVM_S390_STORE_STATUS_NOADDR);
 168                 if (rc >= 0)
 169                         rc = -EOPNOTSUPP;
 170         } else
 171                 spin_unlock_bh(&vcpu->arch.local_int.lock);
 172         return rc;
 173 }
 174
 175 static int handle_validity(struct kvm_vcpu *vcpu)
 176 {
 177         unsigned long vmaddr;
 178         int viwhy = vcpu->arch.sie_block->ipb >> 16;
 179         int rc;
 180
 181         vcpu->stat.exit_validity++;
 182         trace_kvm_s390_intercept_validity(vcpu, viwhy);
 183         if (viwhy == 0x37) {
 184                 vmaddr = gmap_fault(vcpu->arch.sie_block->prefix,
 185                                     vcpu->arch.gmap);
 186                 if (IS_ERR_VALUE(vmaddr)) {
 187                         rc = -EOPNOTSUPP;
 188                         goto out;
 189                 }
 190                 rc = fault_in_pages_writeable((char __user *) vmaddr,
 191                          PAGE_SIZE);
 192                 if (rc) {
 193                         /* user will receive sigsegv, exit to user */
 194                         rc = -EOPNOTSUPP;
 195                         goto out;
 196                 }
 197                 vmaddr = gmap_fault(vcpu->arch.sie_block->prefix + PAGE_SIZE,
 198                                     vcpu->arch.gmap);
 199                 if (IS_ERR_VALUE(vmaddr)) {
 200                         rc = -EOPNOTSUPP;
 201                         goto out;
 202                 }
 203                 rc = fault_in_pages_writeable((char __user *) vmaddr,
 204                          PAGE_SIZE);
 205                 if (rc) {
 206                         /* user will receive sigsegv, exit to user */
 207                         rc = -EOPNOTSUPP;
 208                         goto out;
 209                 }
 210         } else
 211                 rc = -EOPNOTSUPP;
 212
 213 out:
 214         if (rc)
 215                 VCPU_EVENT(vcpu, 2, "unhandled validity intercept code %d",
 216                            viwhy);
 217         return rc;
 218 }
 219
 220 static int handle_instruction(struct kvm_vcpu *vcpu)
 221 {
 222         intercept_handler_t handler;
 223
 224         vcpu->stat.exit_instruction++;
 225         trace_kvm_s390_intercept_instruction(vcpu,
 226                                              vcpu->arch.sie_block->ipa,
 227                                              vcpu->arch.sie_block->ipb);
 228         handler = instruction_handlers[vcpu->arch.sie_block->ipa >> 8];
 229         if (handler)
 230                 return handler(vcpu);
 231         return -EOPNOTSUPP;
 232 }
 233
 234 static int handle_prog(struct kvm_vcpu *vcpu)
 235 {
 236         vcpu->stat.exit_program_interruption++;
 237         trace_kvm_s390_intercept_prog(vcpu, vcpu->arch.sie_block->iprcc);
 238         return kvm_s390_inject_program_int(vcpu, vcpu->arch.sie_block->iprcc);
 239 }
 240
 241 static int handle_instruction_and_prog(struct kvm_vcpu *vcpu)
 242 {
 243         int rc, rc2;
 244
 245         vcpu->stat.exit_instr_and_program++;
 246         rc = handle_instruction(vcpu);
 247         rc2 = handle_prog(vcpu);
 248
 249         if (rc == -EOPNOTSUPP)
 250                 vcpu->arch.sie_block->icptcode = 0x04;
 251         if (rc)
 252                 return rc;
 253         return rc2;
 254 }
 255
 256 static const intercept_handler_t intercept_funcs[] = {
 257         [0x00 >> 2] = handle_noop,
 258         [0x04 >> 2] = handle_instruction,
 259         [0x08 >> 2] = handle_prog,
 260         [0x0C >> 2] = handle_instruction_and_prog,
 261         [0x10 >> 2] = handle_noop,
 262         [0x14 >> 2] = handle_noop,
 263         [0x18 >> 2] = handle_noop,
 264         [0x1C >> 2] = kvm_s390_handle_wait,
 265         [0x20 >> 2] = handle_validity,
 266         [0x28 >> 2] = handle_stop,
 267 };
 268
 269 int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
 270 {
 271         intercept_handler_t func;
 272         u8 code = vcpu->arch.sie_block->icptcode;
 273
 274         if (code & 3 || (code >> 2) >= ARRAY_SIZE(intercept_funcs))
 275                 return -EOPNOTSUPP;
 276         func = intercept_funcs[code >> 2];
 277         if (func)
 278                 return func(vcpu);
 279         return -EOPNOTSUPP;
 280 }