arch/s390/kvm/intercept.c

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