linux/arch/s390/kvm/priv.c
<<
>>
Prefs
   1/*
   2 * priv.c - handling privileged instructions
   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.h>
  15#include <linux/gfp.h>
  16#include <linux/errno.h>
  17#include <asm/current.h>
  18#include <asm/debug.h>
  19#include <asm/ebcdic.h>
  20#include <asm/sysinfo.h>
  21#include "gaccess.h"
  22#include "kvm-s390.h"
  23
  24static int handle_set_prefix(struct kvm_vcpu *vcpu)
  25{
  26        int base2 = vcpu->arch.sie_block->ipb >> 28;
  27        int disp2 = ((vcpu->arch.sie_block->ipb & 0x0fff0000) >> 16);
  28        u64 operand2;
  29        u32 address = 0;
  30        u8 tmp;
  31
  32        vcpu->stat.instruction_spx++;
  33
  34        operand2 = disp2;
  35        if (base2)
  36                operand2 += vcpu->arch.guest_gprs[base2];
  37
  38        /* must be word boundary */
  39        if (operand2 & 3) {
  40                kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
  41                goto out;
  42        }
  43
  44        /* get the value */
  45        if (get_guest_u32(vcpu, operand2, &address)) {
  46                kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
  47                goto out;
  48        }
  49
  50        address = address & 0x7fffe000u;
  51
  52        /* make sure that the new value is valid memory */
  53        if (copy_from_guest_absolute(vcpu, &tmp, address, 1) ||
  54           (copy_from_guest_absolute(vcpu, &tmp, address + PAGE_SIZE, 1))) {
  55                kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
  56                goto out;
  57        }
  58
  59        vcpu->arch.sie_block->prefix = address;
  60        vcpu->arch.sie_block->ihcpu = 0xffff;
  61
  62        VCPU_EVENT(vcpu, 5, "setting prefix to %x", address);
  63out:
  64        return 0;
  65}
  66
  67static int handle_store_prefix(struct kvm_vcpu *vcpu)
  68{
  69        int base2 = vcpu->arch.sie_block->ipb >> 28;
  70        int disp2 = ((vcpu->arch.sie_block->ipb & 0x0fff0000) >> 16);
  71        u64 operand2;
  72        u32 address;
  73
  74        vcpu->stat.instruction_stpx++;
  75        operand2 = disp2;
  76        if (base2)
  77                operand2 += vcpu->arch.guest_gprs[base2];
  78
  79        /* must be word boundary */
  80        if (operand2 & 3) {
  81                kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
  82                goto out;
  83        }
  84
  85        address = vcpu->arch.sie_block->prefix;
  86        address = address & 0x7fffe000u;
  87
  88        /* get the value */
  89        if (put_guest_u32(vcpu, operand2, address)) {
  90                kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
  91                goto out;
  92        }
  93
  94        VCPU_EVENT(vcpu, 5, "storing prefix to %x", address);
  95out:
  96        return 0;
  97}
  98
  99static int handle_store_cpu_address(struct kvm_vcpu *vcpu)
 100{
 101        int base2 = vcpu->arch.sie_block->ipb >> 28;
 102        int disp2 = ((vcpu->arch.sie_block->ipb & 0x0fff0000) >> 16);
 103        u64 useraddr;
 104        int rc;
 105
 106        vcpu->stat.instruction_stap++;
 107        useraddr = disp2;
 108        if (base2)
 109                useraddr += vcpu->arch.guest_gprs[base2];
 110
 111        if (useraddr & 1) {
 112                kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
 113                goto out;
 114        }
 115
 116        rc = put_guest_u16(vcpu, useraddr, vcpu->vcpu_id);
 117        if (rc == -EFAULT) {
 118                kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
 119                goto out;
 120        }
 121
 122        VCPU_EVENT(vcpu, 5, "storing cpu address to %llx", useraddr);
 123out:
 124        return 0;
 125}
 126
 127static int handle_skey(struct kvm_vcpu *vcpu)
 128{
 129        vcpu->stat.instruction_storage_key++;
 130        vcpu->arch.sie_block->gpsw.addr -= 4;
 131        VCPU_EVENT(vcpu, 4, "%s", "retrying storage key operation");
 132        return 0;
 133}
 134
 135static int handle_stsch(struct kvm_vcpu *vcpu)
 136{
 137        vcpu->stat.instruction_stsch++;
 138        VCPU_EVENT(vcpu, 4, "%s", "store subchannel - CC3");
 139        /* condition code 3 */
 140        vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
 141        vcpu->arch.sie_block->gpsw.mask |= (3 & 3ul) << 44;
 142        return 0;
 143}
 144
 145static int handle_chsc(struct kvm_vcpu *vcpu)
 146{
 147        vcpu->stat.instruction_chsc++;
 148        VCPU_EVENT(vcpu, 4, "%s", "channel subsystem call - CC3");
 149        /* condition code 3 */
 150        vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
 151        vcpu->arch.sie_block->gpsw.mask |= (3 & 3ul) << 44;
 152        return 0;
 153}
 154
 155static int handle_stfl(struct kvm_vcpu *vcpu)
 156{
 157        unsigned int facility_list;
 158        int rc;
 159
 160        vcpu->stat.instruction_stfl++;
 161        /* only pass the facility bits, which we can handle */
 162        facility_list = S390_lowcore.stfl_fac_list & 0xff00fff3;
 163
 164        rc = copy_to_guest(vcpu, offsetof(struct _lowcore, stfl_fac_list),
 165                           &facility_list, sizeof(facility_list));
 166        if (rc == -EFAULT)
 167                kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
 168        else
 169                VCPU_EVENT(vcpu, 5, "store facility list value %x",
 170                           facility_list);
 171        return 0;
 172}
 173
 174static int handle_stidp(struct kvm_vcpu *vcpu)
 175{
 176        int base2 = vcpu->arch.sie_block->ipb >> 28;
 177        int disp2 = ((vcpu->arch.sie_block->ipb & 0x0fff0000) >> 16);
 178        u64 operand2;
 179        int rc;
 180
 181        vcpu->stat.instruction_stidp++;
 182        operand2 = disp2;
 183        if (base2)
 184                operand2 += vcpu->arch.guest_gprs[base2];
 185
 186        if (operand2 & 7) {
 187                kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
 188                goto out;
 189        }
 190
 191        rc = put_guest_u64(vcpu, operand2, vcpu->arch.stidp_data);
 192        if (rc == -EFAULT) {
 193                kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
 194                goto out;
 195        }
 196
 197        VCPU_EVENT(vcpu, 5, "%s", "store cpu id");
 198out:
 199        return 0;
 200}
 201
 202static void handle_stsi_3_2_2(struct kvm_vcpu *vcpu, struct sysinfo_3_2_2 *mem)
 203{
 204        struct kvm_s390_float_interrupt *fi = &vcpu->kvm->arch.float_int;
 205        int cpus = 0;
 206        int n;
 207
 208        spin_lock(&fi->lock);
 209        for (n = 0; n < KVM_MAX_VCPUS; n++)
 210                if (fi->local_int[n])
 211                        cpus++;
 212        spin_unlock(&fi->lock);
 213
 214        /* deal with other level 3 hypervisors */
 215        if (stsi(mem, 3, 2, 2) == -ENOSYS)
 216                mem->count = 0;
 217        if (mem->count < 8)
 218                mem->count++;
 219        for (n = mem->count - 1; n > 0 ; n--)
 220                memcpy(&mem->vm[n], &mem->vm[n - 1], sizeof(mem->vm[0]));
 221
 222        mem->vm[0].cpus_total = cpus;
 223        mem->vm[0].cpus_configured = cpus;
 224        mem->vm[0].cpus_standby = 0;
 225        mem->vm[0].cpus_reserved = 0;
 226        mem->vm[0].caf = 1000;
 227        memcpy(mem->vm[0].name, "KVMguest", 8);
 228        ASCEBC(mem->vm[0].name, 8);
 229        memcpy(mem->vm[0].cpi, "KVM/Linux       ", 16);
 230        ASCEBC(mem->vm[0].cpi, 16);
 231}
 232
 233static int handle_stsi(struct kvm_vcpu *vcpu)
 234{
 235        int fc = (vcpu->arch.guest_gprs[0] & 0xf0000000) >> 28;
 236        int sel1 = vcpu->arch.guest_gprs[0] & 0xff;
 237        int sel2 = vcpu->arch.guest_gprs[1] & 0xffff;
 238        int base2 = vcpu->arch.sie_block->ipb >> 28;
 239        int disp2 = ((vcpu->arch.sie_block->ipb & 0x0fff0000) >> 16);
 240        u64 operand2;
 241        unsigned long mem;
 242
 243        vcpu->stat.instruction_stsi++;
 244        VCPU_EVENT(vcpu, 4, "stsi: fc: %x sel1: %x sel2: %x", fc, sel1, sel2);
 245
 246        operand2 = disp2;
 247        if (base2)
 248                operand2 += vcpu->arch.guest_gprs[base2];
 249
 250        if (operand2 & 0xfff && fc > 0)
 251                return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
 252
 253        switch (fc) {
 254        case 0:
 255                vcpu->arch.guest_gprs[0] = 3 << 28;
 256                vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
 257                return 0;
 258        case 1: /* same handling for 1 and 2 */
 259        case 2:
 260                mem = get_zeroed_page(GFP_KERNEL);
 261                if (!mem)
 262                        goto out_fail;
 263                if (stsi((void *) mem, fc, sel1, sel2) == -ENOSYS)
 264                        goto out_mem;
 265                break;
 266        case 3:
 267                if (sel1 != 2 || sel2 != 2)
 268                        goto out_fail;
 269                mem = get_zeroed_page(GFP_KERNEL);
 270                if (!mem)
 271                        goto out_fail;
 272                handle_stsi_3_2_2(vcpu, (void *) mem);
 273                break;
 274        default:
 275                goto out_fail;
 276        }
 277
 278        if (copy_to_guest_absolute(vcpu, operand2, (void *) mem, PAGE_SIZE)) {
 279                kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
 280                goto out_mem;
 281        }
 282        free_page(mem);
 283        vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
 284        vcpu->arch.guest_gprs[0] = 0;
 285        return 0;
 286out_mem:
 287        free_page(mem);
 288out_fail:
 289        /* condition code 3 */
 290        vcpu->arch.sie_block->gpsw.mask |= 3ul << 44;
 291        return 0;
 292}
 293
 294static intercept_handler_t priv_handlers[256] = {
 295        [0x02] = handle_stidp,
 296        [0x10] = handle_set_prefix,
 297        [0x11] = handle_store_prefix,
 298        [0x12] = handle_store_cpu_address,
 299        [0x29] = handle_skey,
 300        [0x2a] = handle_skey,
 301        [0x2b] = handle_skey,
 302        [0x34] = handle_stsch,
 303        [0x5f] = handle_chsc,
 304        [0x7d] = handle_stsi,
 305        [0xb1] = handle_stfl,
 306};
 307
 308int kvm_s390_handle_b2(struct kvm_vcpu *vcpu)
 309{
 310        intercept_handler_t handler;
 311
 312        /*
 313         * a lot of B2 instructions are priviledged. We first check for
 314         * the privileged ones, that we can handle in the kernel. If the
 315         * kernel can handle this instruction, we check for the problem
 316         * state bit and (a) handle the instruction or (b) send a code 2
 317         * program check.
 318         * Anything else goes to userspace.*/
 319        handler = priv_handlers[vcpu->arch.sie_block->ipa & 0x00ff];
 320        if (handler) {
 321                if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
 322                        return kvm_s390_inject_program_int(vcpu,
 323                                                   PGM_PRIVILEGED_OPERATION);
 324                else
 325                        return handler(vcpu);
 326        }
 327        return -EOPNOTSUPP;
 328}
 329