linux/arch/s390/kvm/intercept.c
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   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
  23static 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
  64static 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
 103static 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        [0xeb] = handle_lctlg,
 109};
 110
 111static int handle_noop(struct kvm_vcpu *vcpu)
 112{
 113        switch (vcpu->arch.sie_block->icptcode) {
 114        case 0x0:
 115                vcpu->stat.exit_null++;
 116                break;
 117        case 0x10:
 118                vcpu->stat.exit_external_request++;
 119                break;
 120        case 0x14:
 121                vcpu->stat.exit_external_interrupt++;
 122                break;
 123        default:
 124                break; /* nothing */
 125        }
 126        return 0;
 127}
 128
 129static int handle_stop(struct kvm_vcpu *vcpu)
 130{
 131        int rc = 0;
 132
 133        vcpu->stat.exit_stop_request++;
 134        atomic_clear_mask(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags);
 135        spin_lock_bh(&vcpu->arch.local_int.lock);
 136        if (vcpu->arch.local_int.action_bits & ACTION_STORE_ON_STOP) {
 137                vcpu->arch.local_int.action_bits &= ~ACTION_STORE_ON_STOP;
 138                rc = kvm_s390_vcpu_store_status(vcpu,
 139                                                  KVM_S390_STORE_STATUS_NOADDR);
 140                if (rc >= 0)
 141                        rc = -EOPNOTSUPP;
 142        }
 143
 144        if (vcpu->arch.local_int.action_bits & ACTION_RELOADVCPU_ON_STOP) {
 145                vcpu->arch.local_int.action_bits &= ~ACTION_RELOADVCPU_ON_STOP;
 146                rc = SIE_INTERCEPT_RERUNVCPU;
 147                vcpu->run->exit_reason = KVM_EXIT_INTR;
 148        }
 149
 150        if (vcpu->arch.local_int.action_bits & ACTION_STOP_ON_STOP) {
 151                vcpu->arch.local_int.action_bits &= ~ACTION_STOP_ON_STOP;
 152                VCPU_EVENT(vcpu, 3, "%s", "cpu stopped");
 153                rc = -EOPNOTSUPP;
 154        }
 155
 156        spin_unlock_bh(&vcpu->arch.local_int.lock);
 157        return rc;
 158}
 159
 160static int handle_validity(struct kvm_vcpu *vcpu)
 161{
 162        int viwhy = vcpu->arch.sie_block->ipb >> 16;
 163        int rc;
 164
 165        vcpu->stat.exit_validity++;
 166        if ((viwhy == 0x37) && (vcpu->arch.sie_block->prefix
 167                <= kvm_s390_vcpu_get_memsize(vcpu) - 2*PAGE_SIZE)) {
 168                rc = fault_in_pages_writeable((char __user *)
 169                         vcpu->arch.sie_block->gmsor +
 170                         vcpu->arch.sie_block->prefix,
 171                         2*PAGE_SIZE);
 172                if (rc)
 173                        /* user will receive sigsegv, exit to user */
 174                        rc = -EOPNOTSUPP;
 175        } else
 176                rc = -EOPNOTSUPP;
 177
 178        if (rc)
 179                VCPU_EVENT(vcpu, 2, "unhandled validity intercept code %d",
 180                           viwhy);
 181        return rc;
 182}
 183
 184static int handle_instruction(struct kvm_vcpu *vcpu)
 185{
 186        intercept_handler_t handler;
 187
 188        vcpu->stat.exit_instruction++;
 189        handler = instruction_handlers[vcpu->arch.sie_block->ipa >> 8];
 190        if (handler)
 191                return handler(vcpu);
 192        return -EOPNOTSUPP;
 193}
 194
 195static int handle_prog(struct kvm_vcpu *vcpu)
 196{
 197        vcpu->stat.exit_program_interruption++;
 198        return kvm_s390_inject_program_int(vcpu, vcpu->arch.sie_block->iprcc);
 199}
 200
 201static int handle_instruction_and_prog(struct kvm_vcpu *vcpu)
 202{
 203        int rc, rc2;
 204
 205        vcpu->stat.exit_instr_and_program++;
 206        rc = handle_instruction(vcpu);
 207        rc2 = handle_prog(vcpu);
 208
 209        if (rc == -EOPNOTSUPP)
 210                vcpu->arch.sie_block->icptcode = 0x04;
 211        if (rc)
 212                return rc;
 213        return rc2;
 214}
 215
 216static const intercept_handler_t intercept_funcs[] = {
 217        [0x00 >> 2] = handle_noop,
 218        [0x04 >> 2] = handle_instruction,
 219        [0x08 >> 2] = handle_prog,
 220        [0x0C >> 2] = handle_instruction_and_prog,
 221        [0x10 >> 2] = handle_noop,
 222        [0x14 >> 2] = handle_noop,
 223        [0x1C >> 2] = kvm_s390_handle_wait,
 224        [0x20 >> 2] = handle_validity,
 225        [0x28 >> 2] = handle_stop,
 226};
 227
 228int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
 229{
 230        intercept_handler_t func;
 231        u8 code = vcpu->arch.sie_block->icptcode;
 232
 233        if (code & 3 || (code >> 2) >= ARRAY_SIZE(intercept_funcs))
 234                return -EOPNOTSUPP;
 235        func = intercept_funcs[code >> 2];
 236        if (func)
 237                return func(vcpu);
 238        return -EOPNOTSUPP;
 239}
 240