arch/s390/kvm/priv.c

   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
  24 static 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);
  63 out:
  64         return 0;
  65 }
  66
  67 static 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);
  95 out:
  96         return 0;
  97 }
  98
  99 static 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);
 123 out:
 124         return 0;
 125 }
 126
 127 static 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
 135 static 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
 145 static 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
 155 static 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
 174 static 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");
 198 out:
 199         return 0;
 200 }
 201
 202 static 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
 233 static 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;
 286 out_mem:
 287         free_page(mem);
 288 out_fail:
 289         /* condition code 3 */
 290         vcpu->arch.sie_block->gpsw.mask |= 3ul << 44;
 291         return 0;
 292 }
 293
 294 static 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
 308 int 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
 330 static int handle_tprot(struct kvm_vcpu *vcpu)
 331 {
 332         int base1 = (vcpu->arch.sie_block->ipb & 0xf0000000) >> 28;
 333         int disp1 = (vcpu->arch.sie_block->ipb & 0x0fff0000) >> 16;
 334         int base2 = (vcpu->arch.sie_block->ipb & 0xf000) >> 12;
 335         int disp2 = vcpu->arch.sie_block->ipb & 0x0fff;
 336         u64 address1 = disp1 + base1 ? vcpu->arch.guest_gprs[base1] : 0;
 337         u64 address2 = disp2 + base2 ? vcpu->arch.guest_gprs[base2] : 0;
 338         struct vm_area_struct *vma;
 339
 340         vcpu->stat.instruction_tprot++;
 341
 342         /* we only handle the Linux memory detection case:
 343          * access key == 0
 344          * guest DAT == off
 345          * everything else goes to userspace. */
 346         if (address2 & 0xf0)
 347                 return -EOPNOTSUPP;
 348         if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_DAT)
 349                 return -EOPNOTSUPP;
 350
 351
 352         down_read(&current->mm->mmap_sem);
 353         vma = find_vma(current->mm,
 354                         (unsigned long) __guestaddr_to_user(vcpu, address1));
 355         if (!vma) {
 356                 up_read(&current->mm->mmap_sem);
 357                 return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
 358         }
 359
 360         vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
 361         if (!(vma->vm_flags & VM_WRITE) && (vma->vm_flags & VM_READ))
 362                 vcpu->arch.sie_block->gpsw.mask |= (1ul << 44);
 363         if (!(vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_READ))
 364                 vcpu->arch.sie_block->gpsw.mask |= (2ul << 44);
 365
 366         up_read(&current->mm->mmap_sem);
 367         return 0;
 368 }
 369
 370 int kvm_s390_handle_e5(struct kvm_vcpu *vcpu)
 371 {
 372         /* For e5xx... instructions we only handle TPROT */
 373         if ((vcpu->arch.sie_block->ipa & 0x00ff) == 0x01)
 374                 return handle_tprot(vcpu);
 375         return -EOPNOTSUPP;
 376 }
 377