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