arch/s390/kvm/intercept.c

   1 /*
   2  * intercept.c - in-kernel handling for sie intercepts
   3  *
   4  * Copyright IBM Corp. 2008
   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_lctg(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_lctg++;
  34         if ((vcpu->arch.sie_block->ipb & 0xff) != 0x2f)
  35                 return -ENOTSUPP;
  36
  37         useraddr = disp2;
  38         if (base2)
  39                 useraddr += vcpu->arch.guest_gprs[base2];
  40
  41         reg = reg1;
  42
  43         VCPU_EVENT(vcpu, 5, "lctg r1:%x, r3:%x,b2:%x,d2:%x", reg1, reg3, base2,
  44                    disp2);
  45
  46         do {
  47                 rc = get_guest_u64(vcpu, useraddr,
  48                                    &vcpu->arch.sie_block->gcr[reg]);
  49                 if (rc == -EFAULT) {
  50                         kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
  51                         break;
  52                 }
  53                 useraddr += 8;
  54                 if (reg == reg3)
  55                         break;
  56                 reg = (reg + 1) % 16;
  57         } while (1);
  58         return 0;
  59 }
  60
  61 static int handle_lctl(struct kvm_vcpu *vcpu)
  62 {
  63         int reg1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
  64         int reg3 = vcpu->arch.sie_block->ipa & 0x000f;
  65         int base2 = vcpu->arch.sie_block->ipb >> 28;
  66         int disp2 = ((vcpu->arch.sie_block->ipb & 0x0fff0000) >> 16);
  67         u64 useraddr;
  68         u32 val = 0;
  69         int reg, rc;
  70
  71         vcpu->stat.instruction_lctl++;
  72
  73         useraddr = disp2;
  74         if (base2)
  75                 useraddr += vcpu->arch.guest_gprs[base2];
  76
  77         VCPU_EVENT(vcpu, 5, "lctl r1:%x, r3:%x,b2:%x,d2:%x", reg1, reg3, base2,
  78                    disp2);
  79
  80         reg = reg1;
  81         do {
  82                 rc = get_guest_u32(vcpu, useraddr, &val);
  83                 if (rc == -EFAULT) {
  84                         kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
  85                         break;
  86                 }
  87                 vcpu->arch.sie_block->gcr[reg] &= 0xffffffff00000000ul;
  88                 vcpu->arch.sie_block->gcr[reg] |= val;
  89                 useraddr += 4;
  90                 if (reg == reg3)
  91                         break;
  92                 reg = (reg + 1) % 16;
  93         } while (1);
  94         return 0;
  95 }
  96
  97 static intercept_handler_t instruction_handlers[256] = {
  98         [0xae] = kvm_s390_handle_sigp,
  99         [0xb2] = kvm_s390_handle_priv,
 100         [0xb7] = handle_lctl,
 101         [0xeb] = handle_lctg,
 102 };
 103
 104 static int handle_noop(struct kvm_vcpu *vcpu)
 105 {
 106         switch (vcpu->arch.sie_block->icptcode) {
 107         case 0x10:
 108                 vcpu->stat.exit_external_request++;
 109                 break;
 110         case 0x14:
 111                 vcpu->stat.exit_external_interrupt++;
 112                 break;
 113         default:
 114                 break; /* nothing */
 115         }
 116         return 0;
 117 }
 118
 119 static int handle_stop(struct kvm_vcpu *vcpu)
 120 {
 121         int rc;
 122
 123         vcpu->stat.exit_stop_request++;
 124         atomic_clear_mask(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags);
 125         spin_lock_bh(&vcpu->arch.local_int.lock);
 126         if (vcpu->arch.local_int.action_bits & ACTION_STORE_ON_STOP) {
 127                 vcpu->arch.local_int.action_bits &= ~ACTION_STORE_ON_STOP;
 128                 rc = __kvm_s390_vcpu_store_status(vcpu,
 129                                                   KVM_S390_STORE_STATUS_NOADDR);
 130                 if (rc >= 0)
 131                         rc = -ENOTSUPP;
 132         }
 133
 134         if (vcpu->arch.local_int.action_bits & ACTION_STOP_ON_STOP) {
 135                 vcpu->arch.local_int.action_bits &= ~ACTION_STOP_ON_STOP;
 136                 VCPU_EVENT(vcpu, 3, "%s", "cpu stopped");
 137                 rc = -ENOTSUPP;
 138         } else
 139                 rc = 0;
 140         spin_unlock_bh(&vcpu->arch.local_int.lock);
 141         return rc;
 142 }
 143
 144 static int handle_validity(struct kvm_vcpu *vcpu)
 145 {
 146         int viwhy = vcpu->arch.sie_block->ipb >> 16;
 147         vcpu->stat.exit_validity++;
 148         if (viwhy == 0x37) {
 149                 fault_in_pages_writeable((char __user *)
 150                                          vcpu->kvm->arch.guest_origin +
 151                                          vcpu->arch.sie_block->prefix,
 152                                          PAGE_SIZE);
 153                 return 0;
 154         }
 155         VCPU_EVENT(vcpu, 2, "unhandled validity intercept code %d",
 156                    viwhy);
 157         return -ENOTSUPP;
 158 }
 159
 160 static int handle_instruction(struct kvm_vcpu *vcpu)
 161 {
 162         intercept_handler_t handler;
 163
 164         vcpu->stat.exit_instruction++;
 165         handler = instruction_handlers[vcpu->arch.sie_block->ipa >> 8];
 166         if (handler)
 167                 return handler(vcpu);
 168         return -ENOTSUPP;
 169 }
 170
 171 static int handle_prog(struct kvm_vcpu *vcpu)
 172 {
 173         vcpu->stat.exit_program_interruption++;
 174         return kvm_s390_inject_program_int(vcpu, vcpu->arch.sie_block->iprcc);
 175 }
 176
 177 static int handle_instruction_and_prog(struct kvm_vcpu *vcpu)
 178 {
 179         int rc, rc2;
 180
 181         vcpu->stat.exit_instr_and_program++;
 182         rc = handle_instruction(vcpu);
 183         rc2 = handle_prog(vcpu);
 184
 185         if (rc == -ENOTSUPP)
 186                 vcpu->arch.sie_block->icptcode = 0x04;
 187         if (rc)
 188                 return rc;
 189         return rc2;
 190 }
 191
 192 static const intercept_handler_t intercept_funcs[0x48 >> 2] = {
 193         [0x00 >> 2] = handle_noop,
 194         [0x04 >> 2] = handle_instruction,
 195         [0x08 >> 2] = handle_prog,
 196         [0x0C >> 2] = handle_instruction_and_prog,
 197         [0x10 >> 2] = handle_noop,
 198         [0x14 >> 2] = handle_noop,
 199         [0x1C >> 2] = kvm_s390_handle_wait,
 200         [0x20 >> 2] = handle_validity,
 201         [0x28 >> 2] = handle_stop,
 202 };
 203
 204 int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
 205 {
 206         intercept_handler_t func;
 207         u8 code = vcpu->arch.sie_block->icptcode;
 208
 209         if (code & 3 || code > 0x48)
 210                 return -ENOTSUPP;
 211         func = intercept_funcs[code >> 2];
 212         if (func)
 213                 return func(vcpu);
 214         return -ENOTSUPP;
 215 }