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         [0xb2] = kvm_s390_handle_priv,
  99         [0xb7] = handle_lctl,
 100         [0xeb] = handle_lctg,
 101 };
 102
 103 static int handle_noop(struct kvm_vcpu *vcpu)
 104 {
 105         switch (vcpu->arch.sie_block->icptcode) {
 106         case 0x10:
 107                 vcpu->stat.exit_external_request++;
 108                 break;
 109         case 0x14:
 110                 vcpu->stat.exit_external_interrupt++;
 111                 break;
 112         default:
 113                 break; /* nothing */
 114         }
 115         return 0;
 116 }
 117
 118 static int handle_stop(struct kvm_vcpu *vcpu)
 119 {
 120         vcpu->stat.exit_stop_request++;
 121         VCPU_EVENT(vcpu, 3, "%s", "cpu stopped");
 122         atomic_clear_mask(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags);
 123         return -ENOTSUPP;
 124 }
 125
 126 static int handle_validity(struct kvm_vcpu *vcpu)
 127 {
 128         int viwhy = vcpu->arch.sie_block->ipb >> 16;
 129         vcpu->stat.exit_validity++;
 130         if (viwhy == 0x37) {
 131                 fault_in_pages_writeable((char __user *)
 132                                          vcpu->kvm->arch.guest_origin +
 133                                          vcpu->arch.sie_block->prefix,
 134                                          PAGE_SIZE);
 135                 return 0;
 136         }
 137         VCPU_EVENT(vcpu, 2, "unhandled validity intercept code %d",
 138                    viwhy);
 139         return -ENOTSUPP;
 140 }
 141
 142 static int handle_instruction(struct kvm_vcpu *vcpu)
 143 {
 144         intercept_handler_t handler;
 145
 146         vcpu->stat.exit_instruction++;
 147         handler = instruction_handlers[vcpu->arch.sie_block->ipa >> 8];
 148         if (handler)
 149                 return handler(vcpu);
 150         return -ENOTSUPP;
 151 }
 152
 153 static int handle_prog(struct kvm_vcpu *vcpu)
 154 {
 155         vcpu->stat.exit_program_interruption++;
 156         return kvm_s390_inject_program_int(vcpu, vcpu->arch.sie_block->iprcc);
 157 }
 158
 159 static int handle_instruction_and_prog(struct kvm_vcpu *vcpu)
 160 {
 161         int rc, rc2;
 162
 163         vcpu->stat.exit_instr_and_program++;
 164         rc = handle_instruction(vcpu);
 165         rc2 = handle_prog(vcpu);
 166
 167         if (rc == -ENOTSUPP)
 168                 vcpu->arch.sie_block->icptcode = 0x04;
 169         if (rc)
 170                 return rc;
 171         return rc2;
 172 }
 173
 174 static const intercept_handler_t intercept_funcs[0x48 >> 2] = {
 175         [0x00 >> 2] = handle_noop,
 176         [0x04 >> 2] = handle_instruction,
 177         [0x08 >> 2] = handle_prog,
 178         [0x0C >> 2] = handle_instruction_and_prog,
 179         [0x10 >> 2] = handle_noop,
 180         [0x14 >> 2] = handle_noop,
 181         [0x1C >> 2] = kvm_s390_handle_wait,
 182         [0x20 >> 2] = handle_validity,
 183         [0x28 >> 2] = handle_stop,
 184 };
 185
 186 int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
 187 {
 188         intercept_handler_t func;
 189         u8 code = vcpu->arch.sie_block->icptcode;
 190
 191         if (code & 3 || code > 0x48)
 192                 return -ENOTSUPP;
 193         func = intercept_funcs[code >> 2];
 194         if (func)
 195                 return func(vcpu);
 196         return -ENOTSUPP;
 197 }