arch/mips/kvm/kvm_trap_emul.c

   1 /*
   2 * This file is subject to the terms and conditions of the GNU General Public
   3 * License.  See the file "COPYING" in the main directory of this archive
   4 * for more details.
   5 *
   6 * KVM/MIPS: Deliver/Emulate exceptions to the guest kernel
   7 *
   8 * Copyright (C) 2012  MIPS Technologies, Inc.  All rights reserved.
   9 * Authors: Sanjay Lal <sanjayl@kymasys.com>
  10 */
  11
  12 #include <linux/errno.h>
  13 #include <linux/err.h>
  14 #include <linux/module.h>
  15 #include <linux/vmalloc.h>
  16
  17 #include <linux/kvm_host.h>
  18
  19 #include "kvm_mips_opcode.h"
  20 #include "kvm_mips_int.h"
  21
  22 static gpa_t kvm_trap_emul_gva_to_gpa_cb(gva_t gva)
  23 {
  24         gpa_t gpa;
  25         uint32_t kseg = KSEGX(gva);
  26
  27         if ((kseg == CKSEG0) || (kseg == CKSEG1))
  28                 gpa = CPHYSADDR(gva);
  29         else {
  30                 printk("%s: cannot find GPA for GVA: %#lx\n", __func__, gva);
  31                 kvm_mips_dump_host_tlbs();
  32                 gpa = KVM_INVALID_ADDR;
  33         }
  34
  35 #ifdef DEBUG
  36         kvm_debug("%s: gva %#lx, gpa: %#llx\n", __func__, gva, gpa);
  37 #endif
  38
  39         return gpa;
  40 }
  41
  42
  43 static int kvm_trap_emul_handle_cop_unusable(struct kvm_vcpu *vcpu)
  44 {
  45         struct kvm_run *run = vcpu->run;
  46         uint32_t __user *opc = (uint32_t __user *) vcpu->arch.pc;
  47         unsigned long cause = vcpu->arch.host_cp0_cause;
  48         enum emulation_result er = EMULATE_DONE;
  49         int ret = RESUME_GUEST;
  50
  51         if (((cause & CAUSEF_CE) >> CAUSEB_CE) == 1) {
  52                 er = kvm_mips_emulate_fpu_exc(cause, opc, run, vcpu);
  53         } else
  54                 er = kvm_mips_emulate_inst(cause, opc, run, vcpu);
  55
  56         switch (er) {
  57         case EMULATE_DONE:
  58                 ret = RESUME_GUEST;
  59                 break;
  60
  61         case EMULATE_FAIL:
  62                 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
  63                 ret = RESUME_HOST;
  64                 break;
  65
  66         case EMULATE_WAIT:
  67                 run->exit_reason = KVM_EXIT_INTR;
  68                 ret = RESUME_HOST;
  69                 break;
  70
  71         default:
  72                 BUG();
  73         }
  74         return ret;
  75 }
  76
  77 static int kvm_trap_emul_handle_tlb_mod(struct kvm_vcpu *vcpu)
  78 {
  79         struct kvm_run *run = vcpu->run;
  80         uint32_t __user *opc = (uint32_t __user *) vcpu->arch.pc;
  81         unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
  82         unsigned long cause = vcpu->arch.host_cp0_cause;
  83         enum emulation_result er = EMULATE_DONE;
  84         int ret = RESUME_GUEST;
  85
  86         if (KVM_GUEST_KSEGX(badvaddr) < KVM_GUEST_KSEG0
  87             || KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG23) {
  88 #ifdef DEBUG
  89                 kvm_debug
  90                     ("USER/KSEG23 ADDR TLB MOD fault: cause %#lx, PC: %p, BadVaddr: %#lx\n",
  91                      cause, opc, badvaddr);
  92 #endif
  93                 er = kvm_mips_handle_tlbmod(cause, opc, run, vcpu);
  94
  95                 if (er == EMULATE_DONE)
  96                         ret = RESUME_GUEST;
  97                 else {
  98                         run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
  99                         ret = RESUME_HOST;
 100                 }
 101         } else if (KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG0) {
 102                 /* XXXKYMA: The guest kernel does not expect to get this fault when we are not
 103                  * using HIGHMEM. Need to address this in a HIGHMEM kernel
 104                  */
 105                 printk
 106                     ("TLB MOD fault not handled, cause %#lx, PC: %p, BadVaddr: %#lx\n",
 107                      cause, opc, badvaddr);
 108                 kvm_mips_dump_host_tlbs();
 109                 kvm_arch_vcpu_dump_regs(vcpu);
 110                 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 111                 ret = RESUME_HOST;
 112         } else {
 113                 printk
 114                     ("Illegal TLB Mod fault address , cause %#lx, PC: %p, BadVaddr: %#lx\n",
 115                      cause, opc, badvaddr);
 116                 kvm_mips_dump_host_tlbs();
 117                 kvm_arch_vcpu_dump_regs(vcpu);
 118                 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 119                 ret = RESUME_HOST;
 120         }
 121         return ret;
 122 }
 123
 124 static int kvm_trap_emul_handle_tlb_st_miss(struct kvm_vcpu *vcpu)
 125 {
 126         struct kvm_run *run = vcpu->run;
 127         uint32_t __user *opc = (uint32_t __user *) vcpu->arch.pc;
 128         unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
 129         unsigned long cause = vcpu->arch.host_cp0_cause;
 130         enum emulation_result er = EMULATE_DONE;
 131         int ret = RESUME_GUEST;
 132
 133         if (((badvaddr & PAGE_MASK) == KVM_GUEST_COMMPAGE_ADDR)
 134             && KVM_GUEST_KERNEL_MODE(vcpu)) {
 135                 if (kvm_mips_handle_commpage_tlb_fault(badvaddr, vcpu) < 0) {
 136                         run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 137                         ret = RESUME_HOST;
 138                 }
 139         } else if (KVM_GUEST_KSEGX(badvaddr) < KVM_GUEST_KSEG0
 140                    || KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG23) {
 141 #ifdef DEBUG
 142                 kvm_debug
 143                     ("USER ADDR TLB LD fault: cause %#lx, PC: %p, BadVaddr: %#lx\n",
 144                      cause, opc, badvaddr);
 145 #endif
 146                 er = kvm_mips_handle_tlbmiss(cause, opc, run, vcpu);
 147                 if (er == EMULATE_DONE)
 148                         ret = RESUME_GUEST;
 149                 else {
 150                         run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 151                         ret = RESUME_HOST;
 152                 }
 153         } else if (KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG0) {
 154                 /* All KSEG0 faults are handled by KVM, as the guest kernel does not
 155                  * expect to ever get them
 156                  */
 157                 if (kvm_mips_handle_kseg0_tlb_fault
 158                     (vcpu->arch.host_cp0_badvaddr, vcpu) < 0) {
 159                         run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 160                         ret = RESUME_HOST;
 161                 }
 162         } else {
 163                 kvm_err
 164                     ("Illegal TLB LD fault address , cause %#lx, PC: %p, BadVaddr: %#lx\n",
 165                      cause, opc, badvaddr);
 166                 kvm_mips_dump_host_tlbs();
 167                 kvm_arch_vcpu_dump_regs(vcpu);
 168                 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 169                 ret = RESUME_HOST;
 170         }
 171         return ret;
 172 }
 173
 174 static int kvm_trap_emul_handle_tlb_ld_miss(struct kvm_vcpu *vcpu)
 175 {
 176         struct kvm_run *run = vcpu->run;
 177         uint32_t __user *opc = (uint32_t __user *) vcpu->arch.pc;
 178         unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
 179         unsigned long cause = vcpu->arch.host_cp0_cause;
 180         enum emulation_result er = EMULATE_DONE;
 181         int ret = RESUME_GUEST;
 182
 183         if (((badvaddr & PAGE_MASK) == KVM_GUEST_COMMPAGE_ADDR)
 184             && KVM_GUEST_KERNEL_MODE(vcpu)) {
 185                 if (kvm_mips_handle_commpage_tlb_fault(badvaddr, vcpu) < 0) {
 186                         run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 187                         ret = RESUME_HOST;
 188                 }
 189         } else if (KVM_GUEST_KSEGX(badvaddr) < KVM_GUEST_KSEG0
 190                    || KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG23) {
 191 #ifdef DEBUG
 192                 kvm_debug("USER ADDR TLB ST fault: PC: %#lx, BadVaddr: %#lx\n",
 193                           vcpu->arch.pc, badvaddr);
 194 #endif
 195
 196                 /* User Address (UA) fault, this could happen if
 197                  * (1) TLB entry not present/valid in both Guest and shadow host TLBs, in this
 198                  *     case we pass on the fault to the guest kernel and let it handle it.
 199                  * (2) TLB entry is present in the Guest TLB but not in the shadow, in this
 200                  *     case we inject the TLB from the Guest TLB into the shadow host TLB
 201                  */
 202
 203                 er = kvm_mips_handle_tlbmiss(cause, opc, run, vcpu);
 204                 if (er == EMULATE_DONE)
 205                         ret = RESUME_GUEST;
 206                 else {
 207                         run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 208                         ret = RESUME_HOST;
 209                 }
 210         } else if (KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG0) {
 211                 if (kvm_mips_handle_kseg0_tlb_fault
 212                     (vcpu->arch.host_cp0_badvaddr, vcpu) < 0) {
 213                         run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 214                         ret = RESUME_HOST;
 215                 }
 216         } else {
 217                 printk
 218                     ("Illegal TLB ST fault address , cause %#lx, PC: %p, BadVaddr: %#lx\n",
 219                      cause, opc, badvaddr);
 220                 kvm_mips_dump_host_tlbs();
 221                 kvm_arch_vcpu_dump_regs(vcpu);
 222                 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 223                 ret = RESUME_HOST;
 224         }
 225         return ret;
 226 }
 227
 228 static int kvm_trap_emul_handle_addr_err_st(struct kvm_vcpu *vcpu)
 229 {
 230         struct kvm_run *run = vcpu->run;
 231         uint32_t __user *opc = (uint32_t __user *) vcpu->arch.pc;
 232         unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
 233         unsigned long cause = vcpu->arch.host_cp0_cause;
 234         enum emulation_result er = EMULATE_DONE;
 235         int ret = RESUME_GUEST;
 236
 237         if (KVM_GUEST_KERNEL_MODE(vcpu)
 238             && (KSEGX(badvaddr) == CKSEG0 || KSEGX(badvaddr) == CKSEG1)) {
 239 #ifdef DEBUG
 240                 kvm_debug("Emulate Store to MMIO space\n");
 241 #endif
 242                 er = kvm_mips_emulate_inst(cause, opc, run, vcpu);
 243                 if (er == EMULATE_FAIL) {
 244                         printk("Emulate Store to MMIO space failed\n");
 245                         run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 246                         ret = RESUME_HOST;
 247                 } else {
 248                         run->exit_reason = KVM_EXIT_MMIO;
 249                         ret = RESUME_HOST;
 250                 }
 251         } else {
 252                 printk
 253                     ("Address Error (STORE): cause %#lx, PC: %p, BadVaddr: %#lx\n",
 254                      cause, opc, badvaddr);
 255                 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 256                 ret = RESUME_HOST;
 257         }
 258         return ret;
 259 }
 260
 261 static int kvm_trap_emul_handle_addr_err_ld(struct kvm_vcpu *vcpu)
 262 {
 263         struct kvm_run *run = vcpu->run;
 264         uint32_t __user *opc = (uint32_t __user *) vcpu->arch.pc;
 265         unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
 266         unsigned long cause = vcpu->arch.host_cp0_cause;
 267         enum emulation_result er = EMULATE_DONE;
 268         int ret = RESUME_GUEST;
 269
 270         if (KSEGX(badvaddr) == CKSEG0 || KSEGX(badvaddr) == CKSEG1) {
 271 #ifdef DEBUG
 272                 kvm_debug("Emulate Load from MMIO space @ %#lx\n", badvaddr);
 273 #endif
 274                 er = kvm_mips_emulate_inst(cause, opc, run, vcpu);
 275                 if (er == EMULATE_FAIL) {
 276                         printk("Emulate Load from MMIO space failed\n");
 277                         run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 278                         ret = RESUME_HOST;
 279                 } else {
 280                         run->exit_reason = KVM_EXIT_MMIO;
 281                         ret = RESUME_HOST;
 282                 }
 283         } else {
 284                 printk
 285                     ("Address Error (LOAD): cause %#lx, PC: %p, BadVaddr: %#lx\n",
 286                      cause, opc, badvaddr);
 287                 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 288                 ret = RESUME_HOST;
 289                 er = EMULATE_FAIL;
 290         }
 291         return ret;
 292 }
 293
 294 static int kvm_trap_emul_handle_syscall(struct kvm_vcpu *vcpu)
 295 {
 296         struct kvm_run *run = vcpu->run;
 297         uint32_t __user *opc = (uint32_t __user *) vcpu->arch.pc;
 298         unsigned long cause = vcpu->arch.host_cp0_cause;
 299         enum emulation_result er = EMULATE_DONE;
 300         int ret = RESUME_GUEST;
 301
 302         er = kvm_mips_emulate_syscall(cause, opc, run, vcpu);
 303         if (er == EMULATE_DONE)
 304                 ret = RESUME_GUEST;
 305         else {
 306                 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 307                 ret = RESUME_HOST;
 308         }
 309         return ret;
 310 }
 311
 312 static int kvm_trap_emul_handle_res_inst(struct kvm_vcpu *vcpu)
 313 {
 314         struct kvm_run *run = vcpu->run;
 315         uint32_t __user *opc = (uint32_t __user *) vcpu->arch.pc;
 316         unsigned long cause = vcpu->arch.host_cp0_cause;
 317         enum emulation_result er = EMULATE_DONE;
 318         int ret = RESUME_GUEST;
 319
 320         er = kvm_mips_handle_ri(cause, opc, run, vcpu);
 321         if (er == EMULATE_DONE)
 322                 ret = RESUME_GUEST;
 323         else {
 324                 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 325                 ret = RESUME_HOST;
 326         }
 327         return ret;
 328 }
 329
 330 static int kvm_trap_emul_handle_break(struct kvm_vcpu *vcpu)
 331 {
 332         struct kvm_run *run = vcpu->run;
 333         uint32_t __user *opc = (uint32_t __user *) vcpu->arch.pc;
 334         unsigned long cause = vcpu->arch.host_cp0_cause;
 335         enum emulation_result er = EMULATE_DONE;
 336         int ret = RESUME_GUEST;
 337
 338         er = kvm_mips_emulate_bp_exc(cause, opc, run, vcpu);
 339         if (er == EMULATE_DONE)
 340                 ret = RESUME_GUEST;
 341         else {
 342                 run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 343                 ret = RESUME_HOST;
 344         }
 345         return ret;
 346 }
 347
 348 static int kvm_trap_emul_vm_init(struct kvm *kvm)
 349 {
 350         return 0;
 351 }
 352
 353 static int kvm_trap_emul_vcpu_init(struct kvm_vcpu *vcpu)
 354 {
 355         return 0;
 356 }
 357
 358 static int kvm_trap_emul_vcpu_setup(struct kvm_vcpu *vcpu)
 359 {
 360         struct mips_coproc *cop0 = vcpu->arch.cop0;
 361         uint32_t config1;
 362         int vcpu_id = vcpu->vcpu_id;
 363
 364         /* Arch specific stuff, set up config registers properly so that the
 365          * guest will come up as expected, for now we simulate a
 366          * MIPS 24kc
 367          */
 368         kvm_write_c0_guest_prid(cop0, 0x00019300);
 369         kvm_write_c0_guest_config(cop0,
 370                                   MIPS_CONFIG0 | (0x1 << CP0C0_AR) |
 371                                   (MMU_TYPE_R4000 << CP0C0_MT));
 372
 373         /* Read the cache characteristics from the host Config1 Register */
 374         config1 = (read_c0_config1() & ~0x7f);
 375
 376         /* Set up MMU size */
 377         config1 &= ~(0x3f << 25);
 378         config1 |= ((KVM_MIPS_GUEST_TLB_SIZE - 1) << 25);
 379
 380         /* We unset some bits that we aren't emulating */
 381         config1 &=
 382             ~((1 << CP0C1_C2) | (1 << CP0C1_MD) | (1 << CP0C1_PC) |
 383               (1 << CP0C1_WR) | (1 << CP0C1_CA));
 384         kvm_write_c0_guest_config1(cop0, config1);
 385
 386         kvm_write_c0_guest_config2(cop0, MIPS_CONFIG2);
 387         /* MIPS_CONFIG2 | (read_c0_config2() & 0xfff) */
 388         kvm_write_c0_guest_config3(cop0,
 389                                    MIPS_CONFIG3 | (0 << CP0C3_VInt) | (1 <<
 390                                                                        CP0C3_ULRI));
 391
 392         /* Set Wait IE/IXMT Ignore in Config7, IAR, AR */
 393         kvm_write_c0_guest_config7(cop0, (MIPS_CONF7_WII) | (1 << 10));
 394
 395         /* Setup IntCtl defaults, compatibilty mode for timer interrupts (HW5) */
 396         kvm_write_c0_guest_intctl(cop0, 0xFC000000);
 397
 398         /* Put in vcpu id as CPUNum into Ebase Reg to handle SMP Guests */
 399         kvm_write_c0_guest_ebase(cop0, KVM_GUEST_KSEG0 | (vcpu_id & 0xFF));
 400
 401         return 0;
 402 }
 403
 404 static struct kvm_mips_callbacks kvm_trap_emul_callbacks = {
 405         /* exit handlers */
 406         .handle_cop_unusable = kvm_trap_emul_handle_cop_unusable,
 407         .handle_tlb_mod = kvm_trap_emul_handle_tlb_mod,
 408         .handle_tlb_st_miss = kvm_trap_emul_handle_tlb_st_miss,
 409         .handle_tlb_ld_miss = kvm_trap_emul_handle_tlb_ld_miss,
 410         .handle_addr_err_st = kvm_trap_emul_handle_addr_err_st,
 411         .handle_addr_err_ld = kvm_trap_emul_handle_addr_err_ld,
 412         .handle_syscall = kvm_trap_emul_handle_syscall,
 413         .handle_res_inst = kvm_trap_emul_handle_res_inst,
 414         .handle_break = kvm_trap_emul_handle_break,
 415
 416         .vm_init = kvm_trap_emul_vm_init,
 417         .vcpu_init = kvm_trap_emul_vcpu_init,
 418         .vcpu_setup = kvm_trap_emul_vcpu_setup,
 419         .gva_to_gpa = kvm_trap_emul_gva_to_gpa_cb,
 420         .queue_timer_int = kvm_mips_queue_timer_int_cb,
 421         .dequeue_timer_int = kvm_mips_dequeue_timer_int_cb,
 422         .queue_io_int = kvm_mips_queue_io_int_cb,
 423         .dequeue_io_int = kvm_mips_dequeue_io_int_cb,
 424         .irq_deliver = kvm_mips_irq_deliver_cb,
 425         .irq_clear = kvm_mips_irq_clear_cb,
 426 };
 427
 428 int kvm_mips_emulation_init(struct kvm_mips_callbacks **install_callbacks)
 429 {
 430         *install_callbacks = &kvm_trap_emul_callbacks;
 431         return 0;
 432 }