arch/s390/kvm/priv.c

   1 /*
   2  * 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 #include "trace.h"
  24
  25 static int handle_set_prefix(struct kvm_vcpu *vcpu)
  26 {
  27         int base2 = vcpu->arch.sie_block->ipb >> 28;
  28         int disp2 = ((vcpu->arch.sie_block->ipb & 0x0fff0000) >> 16);
  29         u64 operand2;
  30         u32 address = 0;
  31         u8 tmp;
  32
  33         vcpu->stat.instruction_spx++;
  34
  35         operand2 = disp2;
  36         if (base2)
  37                 operand2 += vcpu->run->s.regs.gprs[base2];
  38
  39         /* must be word boundary */
  40         if (operand2 & 3) {
  41                 kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
  42                 goto out;
  43         }
  44
  45         /* get the value */
  46         if (get_guest_u32(vcpu, operand2, &address)) {
  47                 kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
  48                 goto out;
  49         }
  50
  51         address = address & 0x7fffe000u;
  52
  53         /* make sure that the new value is valid memory */
  54         if (copy_from_guest_absolute(vcpu, &tmp, address, 1) ||
  55            (copy_from_guest_absolute(vcpu, &tmp, address + PAGE_SIZE, 1))) {
  56                 kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
  57                 goto out;
  58         }
  59
  60         kvm_s390_set_prefix(vcpu, address);
  61
  62         VCPU_EVENT(vcpu, 5, "setting prefix to %x", address);
  63         trace_kvm_s390_handle_prefix(vcpu, 1, address);
  64 out:
  65         return 0;
  66 }
  67
  68 static int handle_store_prefix(struct kvm_vcpu *vcpu)
  69 {
  70         int base2 = vcpu->arch.sie_block->ipb >> 28;
  71         int disp2 = ((vcpu->arch.sie_block->ipb & 0x0fff0000) >> 16);
  72         u64 operand2;
  73         u32 address;
  74
  75         vcpu->stat.instruction_stpx++;
  76         operand2 = disp2;
  77         if (base2)
  78                 operand2 += vcpu->run->s.regs.gprs[base2];
  79
  80         /* must be word boundary */
  81         if (operand2 & 3) {
  82                 kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
  83                 goto out;
  84         }
  85
  86         address = vcpu->arch.sie_block->prefix;
  87         address = address & 0x7fffe000u;
  88
  89         /* get the value */
  90         if (put_guest_u32(vcpu, operand2, address)) {
  91                 kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
  92                 goto out;
  93         }
  94
  95         VCPU_EVENT(vcpu, 5, "storing prefix to %x", address);
  96         trace_kvm_s390_handle_prefix(vcpu, 0, address);
  97 out:
  98         return 0;
  99 }
 100
 101 static int handle_store_cpu_address(struct kvm_vcpu *vcpu)
 102 {
 103         int base2 = vcpu->arch.sie_block->ipb >> 28;
 104         int disp2 = ((vcpu->arch.sie_block->ipb & 0x0fff0000) >> 16);
 105         u64 useraddr;
 106         int rc;
 107
 108         vcpu->stat.instruction_stap++;
 109         useraddr = disp2;
 110         if (base2)
 111                 useraddr += vcpu->run->s.regs.gprs[base2];
 112
 113         if (useraddr & 1) {
 114                 kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
 115                 goto out;
 116         }
 117
 118         rc = put_guest_u16(vcpu, useraddr, vcpu->vcpu_id);
 119         if (rc == -EFAULT) {
 120                 kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
 121                 goto out;
 122         }
 123
 124         VCPU_EVENT(vcpu, 5, "storing cpu address to %llx", useraddr);
 125         trace_kvm_s390_handle_stap(vcpu, useraddr);
 126 out:
 127         return 0;
 128 }
 129
 130 static int handle_skey(struct kvm_vcpu *vcpu)
 131 {
 132         vcpu->stat.instruction_storage_key++;
 133         vcpu->arch.sie_block->gpsw.addr -= 4;
 134         VCPU_EVENT(vcpu, 4, "%s", "retrying storage key operation");
 135         return 0;
 136 }
 137
 138 static int handle_stsch(struct kvm_vcpu *vcpu)
 139 {
 140         vcpu->stat.instruction_stsch++;
 141         VCPU_EVENT(vcpu, 4, "%s", "store subchannel - CC3");
 142         /* condition code 3 */
 143         vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
 144         vcpu->arch.sie_block->gpsw.mask |= (3 & 3ul) << 44;
 145         return 0;
 146 }
 147
 148 static int handle_chsc(struct kvm_vcpu *vcpu)
 149 {
 150         vcpu->stat.instruction_chsc++;
 151         VCPU_EVENT(vcpu, 4, "%s", "channel subsystem call - CC3");
 152         /* condition code 3 */
 153         vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
 154         vcpu->arch.sie_block->gpsw.mask |= (3 & 3ul) << 44;
 155         return 0;
 156 }
 157
 158 static int handle_stfl(struct kvm_vcpu *vcpu)
 159 {
 160         unsigned int facility_list;
 161         int rc;
 162
 163         vcpu->stat.instruction_stfl++;
 164         /* only pass the facility bits, which we can handle */
 165         facility_list = S390_lowcore.stfl_fac_list & 0xff00fff3;
 166
 167         rc = copy_to_guest(vcpu, offsetof(struct _lowcore, stfl_fac_list),
 168                            &facility_list, sizeof(facility_list));
 169         if (rc == -EFAULT)
 170                 kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
 171         else {
 172                 VCPU_EVENT(vcpu, 5, "store facility list value %x",
 173                            facility_list);
 174                 trace_kvm_s390_handle_stfl(vcpu, facility_list);
 175         }
 176         return 0;
 177 }
 178
 179 static int handle_stidp(struct kvm_vcpu *vcpu)
 180 {
 181         int base2 = vcpu->arch.sie_block->ipb >> 28;
 182         int disp2 = ((vcpu->arch.sie_block->ipb & 0x0fff0000) >> 16);
 183         u64 operand2;
 184         int rc;
 185
 186         vcpu->stat.instruction_stidp++;
 187         operand2 = disp2;
 188         if (base2)
 189                 operand2 += vcpu->run->s.regs.gprs[base2];
 190
 191         if (operand2 & 7) {
 192                 kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
 193                 goto out;
 194         }
 195
 196         rc = put_guest_u64(vcpu, operand2, vcpu->arch.stidp_data);
 197         if (rc == -EFAULT) {
 198                 kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
 199                 goto out;
 200         }
 201
 202         VCPU_EVENT(vcpu, 5, "%s", "store cpu id");
 203 out:
 204         return 0;
 205 }
 206
 207 static void handle_stsi_3_2_2(struct kvm_vcpu *vcpu, struct sysinfo_3_2_2 *mem)
 208 {
 209         struct kvm_s390_float_interrupt *fi = &vcpu->kvm->arch.float_int;
 210         int cpus = 0;
 211         int n;
 212
 213         spin_lock(&fi->lock);
 214         for (n = 0; n < KVM_MAX_VCPUS; n++)
 215                 if (fi->local_int[n])
 216                         cpus++;
 217         spin_unlock(&fi->lock);
 218
 219         /* deal with other level 3 hypervisors */
 220         if (stsi(mem, 3, 2, 2))
 221                 mem->count = 0;
 222         if (mem->count < 8)
 223                 mem->count++;
 224         for (n = mem->count - 1; n > 0 ; n--)
 225                 memcpy(&mem->vm[n], &mem->vm[n - 1], sizeof(mem->vm[0]));
 226
 227         mem->vm[0].cpus_total = cpus;
 228         mem->vm[0].cpus_configured = cpus;
 229         mem->vm[0].cpus_standby = 0;
 230         mem->vm[0].cpus_reserved = 0;
 231         mem->vm[0].caf = 1000;
 232         memcpy(mem->vm[0].name, "KVMguest", 8);
 233         ASCEBC(mem->vm[0].name, 8);
 234         memcpy(mem->vm[0].cpi, "KVM/Linux       ", 16);
 235         ASCEBC(mem->vm[0].cpi, 16);
 236 }
 237
 238 static int handle_stsi(struct kvm_vcpu *vcpu)
 239 {
 240         int fc = (vcpu->run->s.regs.gprs[0] & 0xf0000000) >> 28;
 241         int sel1 = vcpu->run->s.regs.gprs[0] & 0xff;
 242         int sel2 = vcpu->run->s.regs.gprs[1] & 0xffff;
 243         int base2 = vcpu->arch.sie_block->ipb >> 28;
 244         int disp2 = ((vcpu->arch.sie_block->ipb & 0x0fff0000) >> 16);
 245         u64 operand2;
 246         unsigned long mem;
 247
 248         vcpu->stat.instruction_stsi++;
 249         VCPU_EVENT(vcpu, 4, "stsi: fc: %x sel1: %x sel2: %x", fc, sel1, sel2);
 250
 251         operand2 = disp2;
 252         if (base2)
 253                 operand2 += vcpu->run->s.regs.gprs[base2];
 254
 255         if (operand2 & 0xfff && fc > 0)
 256                 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
 257
 258         switch (fc) {
 259         case 0:
 260                 vcpu->run->s.regs.gprs[0] = 3 << 28;
 261                 vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
 262                 return 0;
 263         case 1: /* same handling for 1 and 2 */
 264         case 2:
 265                 mem = get_zeroed_page(GFP_KERNEL);
 266                 if (!mem)
 267                         goto out_fail;
 268                 if (stsi((void *) mem, fc, sel1, sel2))
 269                         goto out_mem;
 270                 break;
 271         case 3:
 272                 if (sel1 != 2 || sel2 != 2)
 273                         goto out_fail;
 274                 mem = get_zeroed_page(GFP_KERNEL);
 275                 if (!mem)
 276                         goto out_fail;
 277                 handle_stsi_3_2_2(vcpu, (void *) mem);
 278                 break;
 279         default:
 280                 goto out_fail;
 281         }
 282
 283         if (copy_to_guest_absolute(vcpu, operand2, (void *) mem, PAGE_SIZE)) {
 284                 kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
 285                 goto out_mem;
 286         }
 287         trace_kvm_s390_handle_stsi(vcpu, fc, sel1, sel2, operand2);
 288         free_page(mem);
 289         vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
 290         vcpu->run->s.regs.gprs[0] = 0;
 291         return 0;
 292 out_mem:
 293         free_page(mem);
 294 out_fail:
 295         /* condition code 3 */
 296         vcpu->arch.sie_block->gpsw.mask |= 3ul << 44;
 297         return 0;
 298 }
 299
 300 static intercept_handler_t priv_handlers[256] = {
 301         [0x02] = handle_stidp,
 302         [0x10] = handle_set_prefix,
 303         [0x11] = handle_store_prefix,
 304         [0x12] = handle_store_cpu_address,
 305         [0x29] = handle_skey,
 306         [0x2a] = handle_skey,
 307         [0x2b] = handle_skey,
 308         [0x34] = handle_stsch,
 309         [0x5f] = handle_chsc,
 310         [0x7d] = handle_stsi,
 311         [0xb1] = handle_stfl,
 312 };
 313
 314 int kvm_s390_handle_b2(struct kvm_vcpu *vcpu)
 315 {
 316         intercept_handler_t handler;
 317
 318         /*
 319          * a lot of B2 instructions are priviledged. We first check for
 320          * the privileged ones, that we can handle in the kernel. If the
 321          * kernel can handle this instruction, we check for the problem
 322          * state bit and (a) handle the instruction or (b) send a code 2
 323          * program check.
 324          * Anything else goes to userspace.*/
 325         handler = priv_handlers[vcpu->arch.sie_block->ipa & 0x00ff];
 326         if (handler) {
 327                 if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
 328                         return kvm_s390_inject_program_int(vcpu,
 329                                                    PGM_PRIVILEGED_OPERATION);
 330                 else
 331                         return handler(vcpu);
 332         }
 333         return -EOPNOTSUPP;
 334 }
 335
 336 static int handle_tprot(struct kvm_vcpu *vcpu)
 337 {
 338         int base1 = (vcpu->arch.sie_block->ipb & 0xf0000000) >> 28;
 339         int disp1 = (vcpu->arch.sie_block->ipb & 0x0fff0000) >> 16;
 340         int base2 = (vcpu->arch.sie_block->ipb & 0xf000) >> 12;
 341         int disp2 = vcpu->arch.sie_block->ipb & 0x0fff;
 342         u64 address1 = disp1 + base1 ? vcpu->run->s.regs.gprs[base1] : 0;
 343         u64 address2 = disp2 + base2 ? vcpu->run->s.regs.gprs[base2] : 0;
 344         struct vm_area_struct *vma;
 345         unsigned long user_address;
 346
 347         vcpu->stat.instruction_tprot++;
 348
 349         /* we only handle the Linux memory detection case:
 350          * access key == 0
 351          * guest DAT == off
 352          * everything else goes to userspace. */
 353         if (address2 & 0xf0)
 354                 return -EOPNOTSUPP;
 355         if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_DAT)
 356                 return -EOPNOTSUPP;
 357
 358
 359         /* we must resolve the address without holding the mmap semaphore.
 360          * This is ok since the userspace hypervisor is not supposed to change
 361          * the mapping while the guest queries the memory. Otherwise the guest
 362          * might crash or get wrong info anyway. */
 363         user_address = (unsigned long) __guestaddr_to_user(vcpu, address1);
 364
 365         down_read(&current->mm->mmap_sem);
 366         vma = find_vma(current->mm, user_address);
 367         if (!vma) {
 368                 up_read(&current->mm->mmap_sem);
 369                 return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
 370         }
 371
 372         vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
 373         if (!(vma->vm_flags & VM_WRITE) && (vma->vm_flags & VM_READ))
 374                 vcpu->arch.sie_block->gpsw.mask |= (1ul << 44);
 375         if (!(vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_READ))
 376                 vcpu->arch.sie_block->gpsw.mask |= (2ul << 44);
 377
 378         up_read(&current->mm->mmap_sem);
 379         return 0;
 380 }
 381
 382 int kvm_s390_handle_e5(struct kvm_vcpu *vcpu)
 383 {
 384         /* For e5xx... instructions we only handle TPROT */
 385         if ((vcpu->arch.sie_block->ipa & 0x00ff) == 0x01)
 386                 return handle_tprot(vcpu);
 387         return -EOPNOTSUPP;
 388 }
 389
 390 static int handle_sckpf(struct kvm_vcpu *vcpu)
 391 {
 392         u32 value;
 393
 394         if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
 395                 return kvm_s390_inject_program_int(vcpu,
 396                                                    PGM_PRIVILEGED_OPERATION);
 397
 398         if (vcpu->run->s.regs.gprs[0] & 0x00000000ffff0000)
 399                 return kvm_s390_inject_program_int(vcpu,
 400                                                    PGM_SPECIFICATION);
 401
 402         value = vcpu->run->s.regs.gprs[0] & 0x000000000000ffff;
 403         vcpu->arch.sie_block->todpr = value;
 404
 405         return 0;
 406 }
 407
 408 static intercept_handler_t x01_handlers[256] = {
 409         [0x07] = handle_sckpf,
 410 };
 411
 412 int kvm_s390_handle_01(struct kvm_vcpu *vcpu)
 413 {
 414         intercept_handler_t handler;
 415
 416         handler = x01_handlers[vcpu->arch.sie_block->ipa & 0x00ff];
 417         if (handler)
 418                 return handler(vcpu);
 419         return -EOPNOTSUPP;
 420 }