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   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/kvm_host.h>
  15#include <linux/log2.h>
  16#include <linux/uaccess.h>
  17#include <linux/vmalloc.h>
  18#include <asm/mmu_context.h>
  19#include <asm/pgalloc.h>
  20
  21#include "interrupt.h"
  22
  23static gpa_t kvm_trap_emul_gva_to_gpa_cb(gva_t gva)
  24{
  25	gpa_t gpa;
  26	gva_t kseg = KSEGX(gva);
  27	gva_t gkseg = KVM_GUEST_KSEGX(gva);
  28
  29	if ((kseg == CKSEG0) || (kseg == CKSEG1))
  30		gpa = CPHYSADDR(gva);
  31	else if (gkseg == KVM_GUEST_KSEG0)
  32		gpa = KVM_GUEST_CPHYSADDR(gva);
  33	else {
  34		kvm_err("%s: cannot find GPA for GVA: %#lx\n", __func__, gva);
  35		kvm_mips_dump_host_tlbs();
  36		gpa = KVM_INVALID_ADDR;
  37	}
  38
  39	kvm_debug("%s: gva %#lx, gpa: %#llx\n", __func__, gva, gpa);
  40
  41	return gpa;
  42}
  43
  44static int kvm_trap_emul_no_handler(struct kvm_vcpu *vcpu)
  45{
  46	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
  47	u32 cause = vcpu->arch.host_cp0_cause;
  48	u32 exccode = (cause & CAUSEF_EXCCODE) >> CAUSEB_EXCCODE;
  49	unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
  50	u32 inst = 0;
  51
  52	/*
  53	 *  Fetch the instruction.
  54	 */
  55	if (cause & CAUSEF_BD)
  56		opc += 1;
  57	kvm_get_badinstr(opc, vcpu, &inst);
  58
  59	kvm_err("Exception Code: %d not handled @ PC: %p, inst: 0x%08x BadVaddr: %#lx Status: %#x\n",
  60		exccode, opc, inst, badvaddr,
  61		kvm_read_c0_guest_status(vcpu->arch.cop0));
  62	kvm_arch_vcpu_dump_regs(vcpu);
  63	vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
  64	return RESUME_HOST;
  65}
  66
  67static int kvm_trap_emul_handle_cop_unusable(struct kvm_vcpu *vcpu)
  68{
  69	struct mips_coproc *cop0 = vcpu->arch.cop0;
  70	struct kvm_run *run = vcpu->run;
  71	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
  72	u32 cause = vcpu->arch.host_cp0_cause;
  73	enum emulation_result er = EMULATE_DONE;
  74	int ret = RESUME_GUEST;
  75
  76	if (((cause & CAUSEF_CE) >> CAUSEB_CE) == 1) {
  77		/* FPU Unusable */
  78		if (!kvm_mips_guest_has_fpu(&vcpu->arch) ||
  79		    (kvm_read_c0_guest_status(cop0) & ST0_CU1) == 0) {
  80			/*
  81			 * Unusable/no FPU in guest:
  82			 * deliver guest COP1 Unusable Exception
  83			 */
  84			er = kvm_mips_emulate_fpu_exc(cause, opc, run, vcpu);
  85		} else {
  86			/* Restore FPU state */
  87			kvm_own_fpu(vcpu);
  88			er = EMULATE_DONE;
  89		}
  90	} else {
  91		er = kvm_mips_emulate_inst(cause, opc, run, vcpu);
  92	}
  93
  94	switch (er) {
  95	case EMULATE_DONE:
  96		ret = RESUME_GUEST;
  97		break;
  98
  99	case EMULATE_FAIL:
 100		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 101		ret = RESUME_HOST;
 102		break;
 103
 104	case EMULATE_WAIT:
 105		run->exit_reason = KVM_EXIT_INTR;
 106		ret = RESUME_HOST;
 107		break;
 108
 109	case EMULATE_HYPERCALL:
 110		ret = kvm_mips_handle_hypcall(vcpu);
 111		break;
 112
 113	default:
 114		BUG();
 115	}
 116	return ret;
 117}
 118
 119static int kvm_mips_bad_load(u32 cause, u32 *opc, struct kvm_run *run,
 120			     struct kvm_vcpu *vcpu)
 121{
 122	enum emulation_result er;
 123	union mips_instruction inst;
 124	int err;
 125
 126	/* A code fetch fault doesn't count as an MMIO */
 127	if (kvm_is_ifetch_fault(&vcpu->arch)) {
 128		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 129		return RESUME_HOST;
 130	}
 131
 132	/* Fetch the instruction. */
 133	if (cause & CAUSEF_BD)
 134		opc += 1;
 135	err = kvm_get_badinstr(opc, vcpu, &inst.word);
 136	if (err) {
 137		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 138		return RESUME_HOST;
 139	}
 140
 141	/* Emulate the load */
 142	er = kvm_mips_emulate_load(inst, cause, run, vcpu);
 143	if (er == EMULATE_FAIL) {
 144		kvm_err("Emulate load from MMIO space failed\n");
 145		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 146	} else {
 147		run->exit_reason = KVM_EXIT_MMIO;
 148	}
 149	return RESUME_HOST;
 150}
 151
 152static int kvm_mips_bad_store(u32 cause, u32 *opc, struct kvm_run *run,
 153			      struct kvm_vcpu *vcpu)
 154{
 155	enum emulation_result er;
 156	union mips_instruction inst;
 157	int err;
 158
 159	/* Fetch the instruction. */
 160	if (cause & CAUSEF_BD)
 161		opc += 1;
 162	err = kvm_get_badinstr(opc, vcpu, &inst.word);
 163	if (err) {
 164		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 165		return RESUME_HOST;
 166	}
 167
 168	/* Emulate the store */
 169	er = kvm_mips_emulate_store(inst, cause, run, vcpu);
 170	if (er == EMULATE_FAIL) {
 171		kvm_err("Emulate store to MMIO space failed\n");
 172		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 173	} else {
 174		run->exit_reason = KVM_EXIT_MMIO;
 175	}
 176	return RESUME_HOST;
 177}
 178
 179static int kvm_mips_bad_access(u32 cause, u32 *opc, struct kvm_run *run,
 180			       struct kvm_vcpu *vcpu, bool store)
 181{
 182	if (store)
 183		return kvm_mips_bad_store(cause, opc, run, vcpu);
 184	else
 185		return kvm_mips_bad_load(cause, opc, run, vcpu);
 186}
 187
 188static int kvm_trap_emul_handle_tlb_mod(struct kvm_vcpu *vcpu)
 189{
 190	struct mips_coproc *cop0 = vcpu->arch.cop0;
 191	struct kvm_run *run = vcpu->run;
 192	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
 193	unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
 194	u32 cause = vcpu->arch.host_cp0_cause;
 195	struct kvm_mips_tlb *tlb;
 196	unsigned long entryhi;
 197	int index;
 198
 199	if (KVM_GUEST_KSEGX(badvaddr) < KVM_GUEST_KSEG0
 200	    || KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG23) {
 201		/*
 202		 * First find the mapping in the guest TLB. If the failure to
 203		 * write was due to the guest TLB, it should be up to the guest
 204		 * to handle it.
 205		 */
 206		entryhi = (badvaddr & VPN2_MASK) |
 207			  (kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID);
 208		index = kvm_mips_guest_tlb_lookup(vcpu, entryhi);
 209
 210		/*
 211		 * These should never happen.
 212		 * They would indicate stale host TLB entries.
 213		 */
 214		if (unlikely(index < 0)) {
 215			run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 216			return RESUME_HOST;
 217		}
 218		tlb = vcpu->arch.guest_tlb + index;
 219		if (unlikely(!TLB_IS_VALID(*tlb, badvaddr))) {
 220			run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 221			return RESUME_HOST;
 222		}
 223
 224		/*
 225		 * Guest entry not dirty? That would explain the TLB modified
 226		 * exception. Relay that on to the guest so it can handle it.
 227		 */
 228		if (!TLB_IS_DIRTY(*tlb, badvaddr)) {
 229			kvm_mips_emulate_tlbmod(cause, opc, run, vcpu);
 230			return RESUME_GUEST;
 231		}
 232
 233		if (kvm_mips_handle_mapped_seg_tlb_fault(vcpu, tlb, badvaddr,
 234							 true))
 235			/* Not writable, needs handling as MMIO */
 236			return kvm_mips_bad_store(cause, opc, run, vcpu);
 237		return RESUME_GUEST;
 238	} else if (KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG0) {
 239		if (kvm_mips_handle_kseg0_tlb_fault(badvaddr, vcpu, true) < 0)
 240			/* Not writable, needs handling as MMIO */
 241			return kvm_mips_bad_store(cause, opc, run, vcpu);
 242		return RESUME_GUEST;
 243	} else {
 244		/* host kernel addresses are all handled as MMIO */
 245		return kvm_mips_bad_store(cause, opc, run, vcpu);
 246	}
 247}
 248
 249static int kvm_trap_emul_handle_tlb_miss(struct kvm_vcpu *vcpu, bool store)
 250{
 251	struct kvm_run *run = vcpu->run;
 252	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
 253	unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
 254	u32 cause = vcpu->arch.host_cp0_cause;
 255	enum emulation_result er = EMULATE_DONE;
 256	int ret = RESUME_GUEST;
 257
 258	if (((badvaddr & PAGE_MASK) == KVM_GUEST_COMMPAGE_ADDR)
 259	    && KVM_GUEST_KERNEL_MODE(vcpu)) {
 260		if (kvm_mips_handle_commpage_tlb_fault(badvaddr, vcpu) < 0) {
 261			run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 262			ret = RESUME_HOST;
 263		}
 264	} else if (KVM_GUEST_KSEGX(badvaddr) < KVM_GUEST_KSEG0
 265		   || KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG23) {
 266		kvm_debug("USER ADDR TLB %s fault: cause %#x, PC: %p, BadVaddr: %#lx\n",
 267			  store ? "ST" : "LD", cause, opc, badvaddr);
 268
 269		/*
 270		 * User Address (UA) fault, this could happen if
 271		 * (1) TLB entry not present/valid in both Guest and shadow host
 272		 *     TLBs, in this case we pass on the fault to the guest
 273		 *     kernel and let it handle it.
 274		 * (2) TLB entry is present in the Guest TLB but not in the
 275		 *     shadow, in this case we inject the TLB from the Guest TLB
 276		 *     into the shadow host TLB
 277		 */
 278
 279		er = kvm_mips_handle_tlbmiss(cause, opc, run, vcpu, store);
 280		if (er == EMULATE_DONE)
 281			ret = RESUME_GUEST;
 282		else {
 283			run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 284			ret = RESUME_HOST;
 285		}
 286	} else if (KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG0) {
 287		/*
 288		 * All KSEG0 faults are handled by KVM, as the guest kernel does
 289		 * not expect to ever get them
 290		 */
 291		if (kvm_mips_handle_kseg0_tlb_fault(badvaddr, vcpu, store) < 0)
 292			ret = kvm_mips_bad_access(cause, opc, run, vcpu, store);
 293	} else if (KVM_GUEST_KERNEL_MODE(vcpu)
 294		   && (KSEGX(badvaddr) == CKSEG0 || KSEGX(badvaddr) == CKSEG1)) {
 295		/*
 296		 * With EVA we may get a TLB exception instead of an address
 297		 * error when the guest performs MMIO to KSeg1 addresses.
 298		 */
 299		ret = kvm_mips_bad_access(cause, opc, run, vcpu, store);
 300	} else {
 301		kvm_err("Illegal TLB %s fault address , cause %#x, PC: %p, BadVaddr: %#lx\n",
 302			store ? "ST" : "LD", cause, opc, badvaddr);
 303		kvm_mips_dump_host_tlbs();
 304		kvm_arch_vcpu_dump_regs(vcpu);
 305		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 306		ret = RESUME_HOST;
 307	}
 308	return ret;
 309}
 310
 311static int kvm_trap_emul_handle_tlb_st_miss(struct kvm_vcpu *vcpu)
 312{
 313	return kvm_trap_emul_handle_tlb_miss(vcpu, true);
 314}
 315
 316static int kvm_trap_emul_handle_tlb_ld_miss(struct kvm_vcpu *vcpu)
 317{
 318	return kvm_trap_emul_handle_tlb_miss(vcpu, false);
 319}
 320
 321static int kvm_trap_emul_handle_addr_err_st(struct kvm_vcpu *vcpu)
 322{
 323	struct kvm_run *run = vcpu->run;
 324	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
 325	unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
 326	u32 cause = vcpu->arch.host_cp0_cause;
 327	int ret = RESUME_GUEST;
 328
 329	if (KVM_GUEST_KERNEL_MODE(vcpu)
 330	    && (KSEGX(badvaddr) == CKSEG0 || KSEGX(badvaddr) == CKSEG1)) {
 331		ret = kvm_mips_bad_store(cause, opc, run, vcpu);
 332	} else {
 333		kvm_err("Address Error (STORE): cause %#x, PC: %p, BadVaddr: %#lx\n",
 334			cause, opc, badvaddr);
 335		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 336		ret = RESUME_HOST;
 337	}
 338	return ret;
 339}
 340
 341static int kvm_trap_emul_handle_addr_err_ld(struct kvm_vcpu *vcpu)
 342{
 343	struct kvm_run *run = vcpu->run;
 344	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
 345	unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
 346	u32 cause = vcpu->arch.host_cp0_cause;
 347	int ret = RESUME_GUEST;
 348
 349	if (KSEGX(badvaddr) == CKSEG0 || KSEGX(badvaddr) == CKSEG1) {
 350		ret = kvm_mips_bad_load(cause, opc, run, vcpu);
 351	} else {
 352		kvm_err("Address Error (LOAD): cause %#x, PC: %p, BadVaddr: %#lx\n",
 353			cause, opc, badvaddr);
 354		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 355		ret = RESUME_HOST;
 356	}
 357	return ret;
 358}
 359
 360static int kvm_trap_emul_handle_syscall(struct kvm_vcpu *vcpu)
 361{
 362	struct kvm_run *run = vcpu->run;
 363	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
 364	u32 cause = vcpu->arch.host_cp0_cause;
 365	enum emulation_result er = EMULATE_DONE;
 366	int ret = RESUME_GUEST;
 367
 368	er = kvm_mips_emulate_syscall(cause, opc, run, vcpu);
 369	if (er == EMULATE_DONE)
 370		ret = RESUME_GUEST;
 371	else {
 372		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 373		ret = RESUME_HOST;
 374	}
 375	return ret;
 376}
 377
 378static int kvm_trap_emul_handle_res_inst(struct kvm_vcpu *vcpu)
 379{
 380	struct kvm_run *run = vcpu->run;
 381	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
 382	u32 cause = vcpu->arch.host_cp0_cause;
 383	enum emulation_result er = EMULATE_DONE;
 384	int ret = RESUME_GUEST;
 385
 386	er = kvm_mips_handle_ri(cause, opc, run, vcpu);
 387	if (er == EMULATE_DONE)
 388		ret = RESUME_GUEST;
 389	else {
 390		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 391		ret = RESUME_HOST;
 392	}
 393	return ret;
 394}
 395
 396static int kvm_trap_emul_handle_break(struct kvm_vcpu *vcpu)
 397{
 398	struct kvm_run *run = vcpu->run;
 399	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
 400	u32 cause = vcpu->arch.host_cp0_cause;
 401	enum emulation_result er = EMULATE_DONE;
 402	int ret = RESUME_GUEST;
 403
 404	er = kvm_mips_emulate_bp_exc(cause, opc, run, vcpu);
 405	if (er == EMULATE_DONE)
 406		ret = RESUME_GUEST;
 407	else {
 408		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 409		ret = RESUME_HOST;
 410	}
 411	return ret;
 412}
 413
 414static int kvm_trap_emul_handle_trap(struct kvm_vcpu *vcpu)
 415{
 416	struct kvm_run *run = vcpu->run;
 417	u32 __user *opc = (u32 __user *)vcpu->arch.pc;
 418	u32 cause = vcpu->arch.host_cp0_cause;
 419	enum emulation_result er = EMULATE_DONE;
 420	int ret = RESUME_GUEST;
 421
 422	er = kvm_mips_emulate_trap_exc(cause, opc, run, vcpu);
 423	if (er == EMULATE_DONE) {
 424		ret = RESUME_GUEST;
 425	} else {
 426		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 427		ret = RESUME_HOST;
 428	}
 429	return ret;
 430}
 431
 432static int kvm_trap_emul_handle_msa_fpe(struct kvm_vcpu *vcpu)
 433{
 434	struct kvm_run *run = vcpu->run;
 435	u32 __user *opc = (u32 __user *)vcpu->arch.pc;
 436	u32 cause = vcpu->arch.host_cp0_cause;
 437	enum emulation_result er = EMULATE_DONE;
 438	int ret = RESUME_GUEST;
 439
 440	er = kvm_mips_emulate_msafpe_exc(cause, opc, run, vcpu);
 441	if (er == EMULATE_DONE) {
 442		ret = RESUME_GUEST;
 443	} else {
 444		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 445		ret = RESUME_HOST;
 446	}
 447	return ret;
 448}
 449
 450static int kvm_trap_emul_handle_fpe(struct kvm_vcpu *vcpu)
 451{
 452	struct kvm_run *run = vcpu->run;
 453	u32 __user *opc = (u32 __user *)vcpu->arch.pc;
 454	u32 cause = vcpu->arch.host_cp0_cause;
 455	enum emulation_result er = EMULATE_DONE;
 456	int ret = RESUME_GUEST;
 457
 458	er = kvm_mips_emulate_fpe_exc(cause, opc, run, vcpu);
 459	if (er == EMULATE_DONE) {
 460		ret = RESUME_GUEST;
 461	} else {
 462		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 463		ret = RESUME_HOST;
 464	}
 465	return ret;
 466}
 467
 468/**
 469 * kvm_trap_emul_handle_msa_disabled() - Guest used MSA while disabled in root.
 470 * @vcpu:	Virtual CPU context.
 471 *
 472 * Handle when the guest attempts to use MSA when it is disabled.
 473 */
 474static int kvm_trap_emul_handle_msa_disabled(struct kvm_vcpu *vcpu)
 475{
 476	struct mips_coproc *cop0 = vcpu->arch.cop0;
 477	struct kvm_run *run = vcpu->run;
 478	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
 479	u32 cause = vcpu->arch.host_cp0_cause;
 480	enum emulation_result er = EMULATE_DONE;
 481	int ret = RESUME_GUEST;
 482
 483	if (!kvm_mips_guest_has_msa(&vcpu->arch) ||
 484	    (kvm_read_c0_guest_status(cop0) & (ST0_CU1 | ST0_FR)) == ST0_CU1) {
 485		/*
 486		 * No MSA in guest, or FPU enabled and not in FR=1 mode,
 487		 * guest reserved instruction exception
 488		 */
 489		er = kvm_mips_emulate_ri_exc(cause, opc, run, vcpu);
 490	} else if (!(kvm_read_c0_guest_config5(cop0) & MIPS_CONF5_MSAEN)) {
 491		/* MSA disabled by guest, guest MSA disabled exception */
 492		er = kvm_mips_emulate_msadis_exc(cause, opc, run, vcpu);
 493	} else {
 494		/* Restore MSA/FPU state */
 495		kvm_own_msa(vcpu);
 496		er = EMULATE_DONE;
 497	}
 498
 499	switch (er) {
 500	case EMULATE_DONE:
 501		ret = RESUME_GUEST;
 502		break;
 503
 504	case EMULATE_FAIL:
 505		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 506		ret = RESUME_HOST;
 507		break;
 508
 509	default:
 510		BUG();
 511	}
 512	return ret;
 513}
 514
 515static int kvm_trap_emul_hardware_enable(void)
 516{
 517	return 0;
 518}
 519
 520static void kvm_trap_emul_hardware_disable(void)
 521{
 522}
 523
 524static int kvm_trap_emul_check_extension(struct kvm *kvm, long ext)
 525{
 526	int r;
 527
 528	switch (ext) {
 529	case KVM_CAP_MIPS_TE:
 530		r = 1;
 531		break;
 532	default:
 533		r = 0;
 534		break;
 535	}
 536
 537	return r;
 538}
 539
 540static int kvm_trap_emul_vcpu_init(struct kvm_vcpu *vcpu)
 541{
 542	struct mm_struct *kern_mm = &vcpu->arch.guest_kernel_mm;
 543	struct mm_struct *user_mm = &vcpu->arch.guest_user_mm;
 544
 545	/*
 546	 * Allocate GVA -> HPA page tables.
 547	 * MIPS doesn't use the mm_struct pointer argument.
 548	 */
 549	kern_mm->pgd = pgd_alloc(kern_mm);
 550	if (!kern_mm->pgd)
 551		return -ENOMEM;
 552
 553	user_mm->pgd = pgd_alloc(user_mm);
 554	if (!user_mm->pgd) {
 555		pgd_free(kern_mm, kern_mm->pgd);
 556		return -ENOMEM;
 557	}
 558
 559	return 0;
 560}
 561
 562static void kvm_mips_emul_free_gva_pt(pgd_t *pgd)
 563{
 564	/* Don't free host kernel page tables copied from init_mm.pgd */
 565	const unsigned long end = 0x80000000;
 566	unsigned long pgd_va, pud_va, pmd_va;
 567	pud_t *pud;
 568	pmd_t *pmd;
 569	pte_t *pte;
 570	int i, j, k;
 571
 572	for (i = 0; i < USER_PTRS_PER_PGD; i++) {
 573		if (pgd_none(pgd[i]))
 574			continue;
 575
 576		pgd_va = (unsigned long)i << PGDIR_SHIFT;
 577		if (pgd_va >= end)
 578			break;
 579		pud = pud_offset(pgd + i, 0);
 580		for (j = 0; j < PTRS_PER_PUD; j++) {
 581			if (pud_none(pud[j]))
 582				continue;
 583
 584			pud_va = pgd_va | ((unsigned long)j << PUD_SHIFT);
 585			if (pud_va >= end)
 586				break;
 587			pmd = pmd_offset(pud + j, 0);
 588			for (k = 0; k < PTRS_PER_PMD; k++) {
 589				if (pmd_none(pmd[k]))
 590					continue;
 591
 592				pmd_va = pud_va | (k << PMD_SHIFT);
 593				if (pmd_va >= end)
 594					break;
 595				pte = pte_offset(pmd + k, 0);
 596				pte_free_kernel(NULL, pte);
 597			}
 598			pmd_free(NULL, pmd);
 599		}
 600		pud_free(NULL, pud);
 601	}
 602	pgd_free(NULL, pgd);
 603}
 604
 605static void kvm_trap_emul_vcpu_uninit(struct kvm_vcpu *vcpu)
 606{
 607	kvm_mips_emul_free_gva_pt(vcpu->arch.guest_kernel_mm.pgd);
 608	kvm_mips_emul_free_gva_pt(vcpu->arch.guest_user_mm.pgd);
 609}
 610
 611static int kvm_trap_emul_vcpu_setup(struct kvm_vcpu *vcpu)
 612{
 613	struct mips_coproc *cop0 = vcpu->arch.cop0;
 614	u32 config, config1;
 615	int vcpu_id = vcpu->vcpu_id;
 616
 617	/* Start off the timer at 100 MHz */
 618	kvm_mips_init_count(vcpu, 100*1000*1000);
 619
 620	/*
 621	 * Arch specific stuff, set up config registers properly so that the
 622	 * guest will come up as expected
 623	 */
 624#ifndef CONFIG_CPU_MIPSR6
 625	/* r2-r5, simulate a MIPS 24kc */
 626	kvm_write_c0_guest_prid(cop0, 0x00019300);
 627#else
 628	/* r6+, simulate a generic QEMU machine */
 629	kvm_write_c0_guest_prid(cop0, 0x00010000);
 630#endif
 631	/*
 632	 * Have config1, Cacheable, noncoherent, write-back, write allocate.
 633	 * Endianness, arch revision & virtually tagged icache should match
 634	 * host.
 635	 */
 636	config = read_c0_config() & MIPS_CONF_AR;
 637	config |= MIPS_CONF_M | CONF_CM_CACHABLE_NONCOHERENT | MIPS_CONF_MT_TLB;
 638#ifdef CONFIG_CPU_BIG_ENDIAN
 639	config |= CONF_BE;
 640#endif
 641	if (cpu_has_vtag_icache)
 642		config |= MIPS_CONF_VI;
 643	kvm_write_c0_guest_config(cop0, config);
 644
 645	/* Read the cache characteristics from the host Config1 Register */
 646	config1 = (read_c0_config1() & ~0x7f);
 647
 648	/* DCache line size not correctly reported in Config1 on Octeon CPUs */
 649	if (cpu_dcache_line_size()) {
 650		config1 &= ~MIPS_CONF1_DL;
 651		config1 |= ((ilog2(cpu_dcache_line_size()) - 1) <<
 652			    MIPS_CONF1_DL_SHF) & MIPS_CONF1_DL;
 653	}
 654
 655	/* Set up MMU size */
 656	config1 &= ~(0x3f << 25);
 657	config1 |= ((KVM_MIPS_GUEST_TLB_SIZE - 1) << 25);
 658
 659	/* We unset some bits that we aren't emulating */
 660	config1 &= ~(MIPS_CONF1_C2 | MIPS_CONF1_MD | MIPS_CONF1_PC |
 661		     MIPS_CONF1_WR | MIPS_CONF1_CA);
 662	kvm_write_c0_guest_config1(cop0, config1);
 663
 664	/* Have config3, no tertiary/secondary caches implemented */
 665	kvm_write_c0_guest_config2(cop0, MIPS_CONF_M);
 666	/* MIPS_CONF_M | (read_c0_config2() & 0xfff) */
 667
 668	/* Have config4, UserLocal */
 669	kvm_write_c0_guest_config3(cop0, MIPS_CONF_M | MIPS_CONF3_ULRI);
 670
 671	/* Have config5 */
 672	kvm_write_c0_guest_config4(cop0, MIPS_CONF_M);
 673
 674	/* No config6 */
 675	kvm_write_c0_guest_config5(cop0, 0);
 676
 677	/* Set Wait IE/IXMT Ignore in Config7, IAR, AR */
 678	kvm_write_c0_guest_config7(cop0, (MIPS_CONF7_WII) | (1 << 10));
 679
 680	/* Status */
 681	kvm_write_c0_guest_status(cop0, ST0_BEV | ST0_ERL);
 682
 683	/*
 684	 * Setup IntCtl defaults, compatibility mode for timer interrupts (HW5)
 685	 */
 686	kvm_write_c0_guest_intctl(cop0, 0xFC000000);
 687
 688	/* Put in vcpu id as CPUNum into Ebase Reg to handle SMP Guests */
 689	kvm_write_c0_guest_ebase(cop0, KVM_GUEST_KSEG0 |
 690				       (vcpu_id & MIPS_EBASE_CPUNUM));
 691
 692	/* Put PC at guest reset vector */
 693	vcpu->arch.pc = KVM_GUEST_CKSEG1ADDR(0x1fc00000);
 694
 695	return 0;
 696}
 697
 698static void kvm_trap_emul_flush_shadow_all(struct kvm *kvm)
 699{
 700	/* Flush GVA page tables and invalidate GVA ASIDs on all VCPUs */
 701	kvm_flush_remote_tlbs(kvm);
 702}
 703
 704static void kvm_trap_emul_flush_shadow_memslot(struct kvm *kvm,
 705					const struct kvm_memory_slot *slot)
 706{
 707	kvm_trap_emul_flush_shadow_all(kvm);
 708}
 709
 710static u64 kvm_trap_emul_get_one_regs[] = {
 711	KVM_REG_MIPS_CP0_INDEX,
 712	KVM_REG_MIPS_CP0_ENTRYLO0,
 713	KVM_REG_MIPS_CP0_ENTRYLO1,
 714	KVM_REG_MIPS_CP0_CONTEXT,
 715	KVM_REG_MIPS_CP0_USERLOCAL,
 716	KVM_REG_MIPS_CP0_PAGEMASK,
 717	KVM_REG_MIPS_CP0_WIRED,
 718	KVM_REG_MIPS_CP0_HWRENA,
 719	KVM_REG_MIPS_CP0_BADVADDR,
 720	KVM_REG_MIPS_CP0_COUNT,
 721	KVM_REG_MIPS_CP0_ENTRYHI,
 722	KVM_REG_MIPS_CP0_COMPARE,
 723	KVM_REG_MIPS_CP0_STATUS,
 724	KVM_REG_MIPS_CP0_INTCTL,
 725	KVM_REG_MIPS_CP0_CAUSE,
 726	KVM_REG_MIPS_CP0_EPC,
 727	KVM_REG_MIPS_CP0_PRID,
 728	KVM_REG_MIPS_CP0_EBASE,
 729	KVM_REG_MIPS_CP0_CONFIG,
 730	KVM_REG_MIPS_CP0_CONFIG1,
 731	KVM_REG_MIPS_CP0_CONFIG2,
 732	KVM_REG_MIPS_CP0_CONFIG3,
 733	KVM_REG_MIPS_CP0_CONFIG4,
 734	KVM_REG_MIPS_CP0_CONFIG5,
 735	KVM_REG_MIPS_CP0_CONFIG7,
 736	KVM_REG_MIPS_CP0_ERROREPC,
 737	KVM_REG_MIPS_CP0_KSCRATCH1,
 738	KVM_REG_MIPS_CP0_KSCRATCH2,
 739	KVM_REG_MIPS_CP0_KSCRATCH3,
 740	KVM_REG_MIPS_CP0_KSCRATCH4,
 741	KVM_REG_MIPS_CP0_KSCRATCH5,
 742	KVM_REG_MIPS_CP0_KSCRATCH6,
 743
 744	KVM_REG_MIPS_COUNT_CTL,
 745	KVM_REG_MIPS_COUNT_RESUME,
 746	KVM_REG_MIPS_COUNT_HZ,
 747};
 748
 749static unsigned long kvm_trap_emul_num_regs(struct kvm_vcpu *vcpu)
 750{
 751	return ARRAY_SIZE(kvm_trap_emul_get_one_regs);
 752}
 753
 754static int kvm_trap_emul_copy_reg_indices(struct kvm_vcpu *vcpu,
 755					  u64 __user *indices)
 756{
 757	if (copy_to_user(indices, kvm_trap_emul_get_one_regs,
 758			 sizeof(kvm_trap_emul_get_one_regs)))
 759		return -EFAULT;
 760	indices += ARRAY_SIZE(kvm_trap_emul_get_one_regs);
 761
 762	return 0;
 763}
 764
 765static int kvm_trap_emul_get_one_reg(struct kvm_vcpu *vcpu,
 766				     const struct kvm_one_reg *reg,
 767				     s64 *v)
 768{
 769	struct mips_coproc *cop0 = vcpu->arch.cop0;
 770
 771	switch (reg->id) {
 772	case KVM_REG_MIPS_CP0_INDEX:
 773		*v = (long)kvm_read_c0_guest_index(cop0);
 774		break;
 775	case KVM_REG_MIPS_CP0_ENTRYLO0:
 776		*v = kvm_read_c0_guest_entrylo0(cop0);
 777		break;
 778	case KVM_REG_MIPS_CP0_ENTRYLO1:
 779		*v = kvm_read_c0_guest_entrylo1(cop0);
 780		break;
 781	case KVM_REG_MIPS_CP0_CONTEXT:
 782		*v = (long)kvm_read_c0_guest_context(cop0);
 783		break;
 784	case KVM_REG_MIPS_CP0_USERLOCAL:
 785		*v = (long)kvm_read_c0_guest_userlocal(cop0);
 786		break;
 787	case KVM_REG_MIPS_CP0_PAGEMASK:
 788		*v = (long)kvm_read_c0_guest_pagemask(cop0);
 789		break;
 790	case KVM_REG_MIPS_CP0_WIRED:
 791		*v = (long)kvm_read_c0_guest_wired(cop0);
 792		break;
 793	case KVM_REG_MIPS_CP0_HWRENA:
 794		*v = (long)kvm_read_c0_guest_hwrena(cop0);
 795		break;
 796	case KVM_REG_MIPS_CP0_BADVADDR:
 797		*v = (long)kvm_read_c0_guest_badvaddr(cop0);
 798		break;
 799	case KVM_REG_MIPS_CP0_ENTRYHI:
 800		*v = (long)kvm_read_c0_guest_entryhi(cop0);
 801		break;
 802	case KVM_REG_MIPS_CP0_COMPARE:
 803		*v = (long)kvm_read_c0_guest_compare(cop0);
 804		break;
 805	case KVM_REG_MIPS_CP0_STATUS:
 806		*v = (long)kvm_read_c0_guest_status(cop0);
 807		break;
 808	case KVM_REG_MIPS_CP0_INTCTL:
 809		*v = (long)kvm_read_c0_guest_intctl(cop0);
 810		break;
 811	case KVM_REG_MIPS_CP0_CAUSE:
 812		*v = (long)kvm_read_c0_guest_cause(cop0);
 813		break;
 814	case KVM_REG_MIPS_CP0_EPC:
 815		*v = (long)kvm_read_c0_guest_epc(cop0);
 816		break;
 817	case KVM_REG_MIPS_CP0_PRID:
 818		*v = (long)kvm_read_c0_guest_prid(cop0);
 819		break;
 820	case KVM_REG_MIPS_CP0_EBASE:
 821		*v = (long)kvm_read_c0_guest_ebase(cop0);
 822		break;
 823	case KVM_REG_MIPS_CP0_CONFIG:
 824		*v = (long)kvm_read_c0_guest_config(cop0);
 825		break;
 826	case KVM_REG_MIPS_CP0_CONFIG1:
 827		*v = (long)kvm_read_c0_guest_config1(cop0);
 828		break;
 829	case KVM_REG_MIPS_CP0_CONFIG2:
 830		*v = (long)kvm_read_c0_guest_config2(cop0);
 831		break;
 832	case KVM_REG_MIPS_CP0_CONFIG3:
 833		*v = (long)kvm_read_c0_guest_config3(cop0);
 834		break;
 835	case KVM_REG_MIPS_CP0_CONFIG4:
 836		*v = (long)kvm_read_c0_guest_config4(cop0);
 837		break;
 838	case KVM_REG_MIPS_CP0_CONFIG5:
 839		*v = (long)kvm_read_c0_guest_config5(cop0);
 840		break;
 841	case KVM_REG_MIPS_CP0_CONFIG7:
 842		*v = (long)kvm_read_c0_guest_config7(cop0);
 843		break;
 844	case KVM_REG_MIPS_CP0_COUNT:
 845		*v = kvm_mips_read_count(vcpu);
 846		break;
 847	case KVM_REG_MIPS_COUNT_CTL:
 848		*v = vcpu->arch.count_ctl;
 849		break;
 850	case KVM_REG_MIPS_COUNT_RESUME:
 851		*v = ktime_to_ns(vcpu->arch.count_resume);
 852		break;
 853	case KVM_REG_MIPS_COUNT_HZ:
 854		*v = vcpu->arch.count_hz;
 855		break;
 856	case KVM_REG_MIPS_CP0_ERROREPC:
 857		*v = (long)kvm_read_c0_guest_errorepc(cop0);
 858		break;
 859	case KVM_REG_MIPS_CP0_KSCRATCH1:
 860		*v = (long)kvm_read_c0_guest_kscratch1(cop0);
 861		break;
 862	case KVM_REG_MIPS_CP0_KSCRATCH2:
 863		*v = (long)kvm_read_c0_guest_kscratch2(cop0);
 864		break;
 865	case KVM_REG_MIPS_CP0_KSCRATCH3:
 866		*v = (long)kvm_read_c0_guest_kscratch3(cop0);
 867		break;
 868	case KVM_REG_MIPS_CP0_KSCRATCH4:
 869		*v = (long)kvm_read_c0_guest_kscratch4(cop0);
 870		break;
 871	case KVM_REG_MIPS_CP0_KSCRATCH5:
 872		*v = (long)kvm_read_c0_guest_kscratch5(cop0);
 873		break;
 874	case KVM_REG_MIPS_CP0_KSCRATCH6:
 875		*v = (long)kvm_read_c0_guest_kscratch6(cop0);
 876		break;
 877	default:
 878		return -EINVAL;
 879	}
 880	return 0;
 881}
 882
 883static int kvm_trap_emul_set_one_reg(struct kvm_vcpu *vcpu,
 884				     const struct kvm_one_reg *reg,
 885				     s64 v)
 886{
 887	struct mips_coproc *cop0 = vcpu->arch.cop0;
 888	int ret = 0;
 889	unsigned int cur, change;
 890
 891	switch (reg->id) {
 892	case KVM_REG_MIPS_CP0_INDEX:
 893		kvm_write_c0_guest_index(cop0, v);
 894		break;
 895	case KVM_REG_MIPS_CP0_ENTRYLO0:
 896		kvm_write_c0_guest_entrylo0(cop0, v);
 897		break;
 898	case KVM_REG_MIPS_CP0_ENTRYLO1:
 899		kvm_write_c0_guest_entrylo1(cop0, v);
 900		break;
 901	case KVM_REG_MIPS_CP0_CONTEXT:
 902		kvm_write_c0_guest_context(cop0, v);
 903		break;
 904	case KVM_REG_MIPS_CP0_USERLOCAL:
 905		kvm_write_c0_guest_userlocal(cop0, v);
 906		break;
 907	case KVM_REG_MIPS_CP0_PAGEMASK:
 908		kvm_write_c0_guest_pagemask(cop0, v);
 909		break;
 910	case KVM_REG_MIPS_CP0_WIRED:
 911		kvm_write_c0_guest_wired(cop0, v);
 912		break;
 913	case KVM_REG_MIPS_CP0_HWRENA:
 914		kvm_write_c0_guest_hwrena(cop0, v);
 915		break;
 916	case KVM_REG_MIPS_CP0_BADVADDR:
 917		kvm_write_c0_guest_badvaddr(cop0, v);
 918		break;
 919	case KVM_REG_MIPS_CP0_ENTRYHI:
 920		kvm_write_c0_guest_entryhi(cop0, v);
 921		break;
 922	case KVM_REG_MIPS_CP0_STATUS:
 923		kvm_write_c0_guest_status(cop0, v);
 924		break;
 925	case KVM_REG_MIPS_CP0_INTCTL:
 926		/* No VInt, so no VS, read-only for now */
 927		break;
 928	case KVM_REG_MIPS_CP0_EPC:
 929		kvm_write_c0_guest_epc(cop0, v);
 930		break;
 931	case KVM_REG_MIPS_CP0_PRID:
 932		kvm_write_c0_guest_prid(cop0, v);
 933		break;
 934	case KVM_REG_MIPS_CP0_EBASE:
 935		/*
 936		 * Allow core number to be written, but the exception base must
 937		 * remain in guest KSeg0.
 938		 */
 939		kvm_change_c0_guest_ebase(cop0, 0x1ffff000 | MIPS_EBASE_CPUNUM,
 940					  v);
 941		break;
 942	case KVM_REG_MIPS_CP0_COUNT:
 943		kvm_mips_write_count(vcpu, v);
 944		break;
 945	case KVM_REG_MIPS_CP0_COMPARE:
 946		kvm_mips_write_compare(vcpu, v, false);
 947		break;
 948	case KVM_REG_MIPS_CP0_CAUSE:
 949		/*
 950		 * If the timer is stopped or started (DC bit) it must look
 951		 * atomic with changes to the interrupt pending bits (TI, IRQ5).
 952		 * A timer interrupt should not happen in between.
 953		 */
 954		if ((kvm_read_c0_guest_cause(cop0) ^ v) & CAUSEF_DC) {
 955			if (v & CAUSEF_DC) {
 956				/* disable timer first */
 957				kvm_mips_count_disable_cause(vcpu);
 958				kvm_change_c0_guest_cause(cop0, (u32)~CAUSEF_DC,
 959							  v);
 960			} else {
 961				/* enable timer last */
 962				kvm_change_c0_guest_cause(cop0, (u32)~CAUSEF_DC,
 963							  v);
 964				kvm_mips_count_enable_cause(vcpu);
 965			}
 966		} else {
 967			kvm_write_c0_guest_cause(cop0, v);
 968		}
 969		break;
 970	case KVM_REG_MIPS_CP0_CONFIG:
 971		/* read-only for now */
 972		break;
 973	case KVM_REG_MIPS_CP0_CONFIG1:
 974		cur = kvm_read_c0_guest_config1(cop0);
 975		change = (cur ^ v) & kvm_mips_config1_wrmask(vcpu);
 976		if (change) {
 977			v = cur ^ change;
 978			kvm_write_c0_guest_config1(cop0, v);
 979		}
 980		break;
 981	case KVM_REG_MIPS_CP0_CONFIG2:
 982		/* read-only for now */
 983		break;
 984	case KVM_REG_MIPS_CP0_CONFIG3:
 985		cur = kvm_read_c0_guest_config3(cop0);
 986		change = (cur ^ v) & kvm_mips_config3_wrmask(vcpu);
 987		if (change) {
 988			v = cur ^ change;
 989			kvm_write_c0_guest_config3(cop0, v);
 990		}
 991		break;
 992	case KVM_REG_MIPS_CP0_CONFIG4:
 993		cur = kvm_read_c0_guest_config4(cop0);
 994		change = (cur ^ v) & kvm_mips_config4_wrmask(vcpu);
 995		if (change) {
 996			v = cur ^ change;
 997			kvm_write_c0_guest_config4(cop0, v);
 998		}
 999		break;
1000	case KVM_REG_MIPS_CP0_CONFIG5:
1001		cur = kvm_read_c0_guest_config5(cop0);
1002		change = (cur ^ v) & kvm_mips_config5_wrmask(vcpu);
1003		if (change) {
1004			v = cur ^ change;
1005			kvm_write_c0_guest_config5(cop0, v);
1006		}
1007		break;
1008	case KVM_REG_MIPS_CP0_CONFIG7:
1009		/* writes ignored */
1010		break;
1011	case KVM_REG_MIPS_COUNT_CTL:
1012		ret = kvm_mips_set_count_ctl(vcpu, v);
1013		break;
1014	case KVM_REG_MIPS_COUNT_RESUME:
1015		ret = kvm_mips_set_count_resume(vcpu, v);
1016		break;
1017	case KVM_REG_MIPS_COUNT_HZ:
1018		ret = kvm_mips_set_count_hz(vcpu, v);
1019		break;
1020	case KVM_REG_MIPS_CP0_ERROREPC:
1021		kvm_write_c0_guest_errorepc(cop0, v);
1022		break;
1023	case KVM_REG_MIPS_CP0_KSCRATCH1:
1024		kvm_write_c0_guest_kscratch1(cop0, v);
1025		break;
1026	case KVM_REG_MIPS_CP0_KSCRATCH2:
1027		kvm_write_c0_guest_kscratch2(cop0, v);
1028		break;
1029	case KVM_REG_MIPS_CP0_KSCRATCH3:
1030		kvm_write_c0_guest_kscratch3(cop0, v);
1031		break;
1032	case KVM_REG_MIPS_CP0_KSCRATCH4:
1033		kvm_write_c0_guest_kscratch4(cop0, v);
1034		break;
1035	case KVM_REG_MIPS_CP0_KSCRATCH5:
1036		kvm_write_c0_guest_kscratch5(cop0, v);
1037		break;
1038	case KVM_REG_MIPS_CP0_KSCRATCH6:
1039		kvm_write_c0_guest_kscratch6(cop0, v);
1040		break;
1041	default:
1042		return -EINVAL;
1043	}
1044	return ret;
1045}
1046
1047static int kvm_trap_emul_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
1048{
1049	struct mm_struct *kern_mm = &vcpu->arch.guest_kernel_mm;
1050	struct mm_struct *user_mm = &vcpu->arch.guest_user_mm;
1051	struct mm_struct *mm;
1052
1053	/*
1054	 * Were we in guest context? If so, restore the appropriate ASID based
1055	 * on the mode of the Guest (Kernel/User).
1056	 */
1057	if (current->flags & PF_VCPU) {
1058		mm = KVM_GUEST_KERNEL_MODE(vcpu) ? kern_mm : user_mm;
1059		check_switch_mmu_context(mm);
1060		kvm_mips_suspend_mm(cpu);
1061		ehb();
1062	}
1063
1064	return 0;
1065}
1066
1067static int kvm_trap_emul_vcpu_put(struct kvm_vcpu *vcpu, int cpu)
1068{
1069	kvm_lose_fpu(vcpu);
1070
1071	if (current->flags & PF_VCPU) {
1072		/* Restore normal Linux process memory map */
1073		check_switch_mmu_context(current->mm);
1074		kvm_mips_resume_mm(cpu);
1075		ehb();
1076	}
1077
1078	return 0;
1079}
1080
1081static void kvm_trap_emul_check_requests(struct kvm_vcpu *vcpu, int cpu,
1082					 bool reload_asid)
1083{
1084	struct mm_struct *kern_mm = &vcpu->arch.guest_kernel_mm;
1085	struct mm_struct *user_mm = &vcpu->arch.guest_user_mm;
1086	struct mm_struct *mm;
1087	int i;
1088
1089	if (likely(!kvm_request_pending(vcpu)))
1090		return;
1091
1092	if (kvm_check_request(KVM_REQ_TLB_FLUSH, vcpu)) {
1093		/*
1094		 * Both kernel & user GVA mappings must be invalidated. The
1095		 * caller is just about to check whether the ASID is stale
1096		 * anyway so no need to reload it here.
1097		 */
1098		kvm_mips_flush_gva_pt(kern_mm->pgd, KMF_GPA | KMF_KERN);
1099		kvm_mips_flush_gva_pt(user_mm->pgd, KMF_GPA | KMF_USER);
1100		for_each_possible_cpu(i) {
1101			set_cpu_context(i, kern_mm, 0);
1102			set_cpu_context(i, user_mm, 0);
1103		}
1104
1105		/* Generate new ASID for current mode */
1106		if (reload_asid) {
1107			mm = KVM_GUEST_KERNEL_MODE(vcpu) ? kern_mm : user_mm;
1108			get_new_mmu_context(mm);
1109			htw_stop();
1110			write_c0_entryhi(cpu_asid(cpu, mm));
1111			TLBMISS_HANDLER_SETUP_PGD(mm->pgd);
1112			htw_start();
1113		}
1114	}
1115}
1116
1117/**
1118 * kvm_trap_emul_gva_lockless_begin() - Begin lockless access to GVA space.
1119 * @vcpu:	VCPU pointer.
1120 *
1121 * Call before a GVA space access outside of guest mode, to ensure that
1122 * asynchronous TLB flush requests are handled or delayed until completion of
1123 * the GVA access (as indicated by a matching kvm_trap_emul_gva_lockless_end()).
1124 *
1125 * Should be called with IRQs already enabled.
1126 */
1127void kvm_trap_emul_gva_lockless_begin(struct kvm_vcpu *vcpu)
1128{
1129	/* We re-enable IRQs in kvm_trap_emul_gva_lockless_end() */
1130	WARN_ON_ONCE(irqs_disabled());
1131
1132	/*
1133	 * The caller is about to access the GVA space, so we set the mode to
1134	 * force TLB flush requests to send an IPI, and also disable IRQs to
1135	 * delay IPI handling until kvm_trap_emul_gva_lockless_end().
1136	 */
1137	local_irq_disable();
1138
1139	/*
1140	 * Make sure the read of VCPU requests is not reordered ahead of the
1141	 * write to vcpu->mode, or we could miss a TLB flush request while
1142	 * the requester sees the VCPU as outside of guest mode and not needing
1143	 * an IPI.
1144	 */
1145	smp_store_mb(vcpu->mode, READING_SHADOW_PAGE_TABLES);
1146
1147	/*
1148	 * If a TLB flush has been requested (potentially while
1149	 * OUTSIDE_GUEST_MODE and assumed immediately effective), perform it
1150	 * before accessing the GVA space, and be sure to reload the ASID if
1151	 * necessary as it'll be immediately used.
1152	 *
1153	 * TLB flush requests after this check will trigger an IPI due to the
1154	 * mode change above, which will be delayed due to IRQs disabled.
1155	 */
1156	kvm_trap_emul_check_requests(vcpu, smp_processor_id(), true);
1157}
1158
1159/**
1160 * kvm_trap_emul_gva_lockless_end() - End lockless access to GVA space.
1161 * @vcpu:	VCPU pointer.
1162 *
1163 * Called after a GVA space access outside of guest mode. Should have a matching
1164 * call to kvm_trap_emul_gva_lockless_begin().
1165 */
1166void kvm_trap_emul_gva_lockless_end(struct kvm_vcpu *vcpu)
1167{
1168	/*
1169	 * Make sure the write to vcpu->mode is not reordered in front of GVA
1170	 * accesses, or a TLB flush requester may not think it necessary to send
1171	 * an IPI.
1172	 */
1173	smp_store_release(&vcpu->mode, OUTSIDE_GUEST_MODE);
1174
1175	/*
1176	 * Now that the access to GVA space is complete, its safe for pending
1177	 * TLB flush request IPIs to be handled (which indicates completion).
1178	 */
1179	local_irq_enable();
1180}
1181
1182static void kvm_trap_emul_vcpu_reenter(struct kvm_run *run,
1183				       struct kvm_vcpu *vcpu)
1184{
1185	struct mm_struct *kern_mm = &vcpu->arch.guest_kernel_mm;
1186	struct mm_struct *user_mm = &vcpu->arch.guest_user_mm;
1187	struct mm_struct *mm;
1188	struct mips_coproc *cop0 = vcpu->arch.cop0;
1189	int i, cpu = smp_processor_id();
1190	unsigned int gasid;
1191
1192	/*
1193	 * No need to reload ASID, IRQs are disabled already so there's no rush,
1194	 * and we'll check if we need to regenerate below anyway before
1195	 * re-entering the guest.
1196	 */
1197	kvm_trap_emul_check_requests(vcpu, cpu, false);
1198
1199	if (KVM_GUEST_KERNEL_MODE(vcpu)) {
1200		mm = kern_mm;
1201	} else {
1202		mm = user_mm;
1203
1204		/*
1205		 * Lazy host ASID regeneration / PT flush for guest user mode.
1206		 * If the guest ASID has changed since the last guest usermode
1207		 * execution, invalidate the stale TLB entries and flush GVA PT
1208		 * entries too.
1209		 */
1210		gasid = kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID;
1211		if (gasid != vcpu->arch.last_user_gasid) {
1212			kvm_mips_flush_gva_pt(user_mm->pgd, KMF_USER);
1213			for_each_possible_cpu(i)
1214				set_cpu_context(i, user_mm, 0);
1215			vcpu->arch.last_user_gasid = gasid;
1216		}
1217	}
1218
1219	/*
1220	 * Check if ASID is stale. This may happen due to a TLB flush request or
1221	 * a lazy user MM invalidation.
1222	 */
1223	check_mmu_context(mm);
1224}
1225
1226static int kvm_trap_emul_vcpu_run(struct kvm_run *run, struct kvm_vcpu *vcpu)
1227{
1228	int cpu = smp_processor_id();
1229	int r;
1230
1231	/* Check if we have any exceptions/interrupts pending */
1232	kvm_mips_deliver_interrupts(vcpu,
1233				    kvm_read_c0_guest_cause(vcpu->arch.cop0));
1234
1235	kvm_trap_emul_vcpu_reenter(run, vcpu);
1236
1237	/*
1238	 * We use user accessors to access guest memory, but we don't want to
1239	 * invoke Linux page faulting.
1240	 */
1241	pagefault_disable();
1242
1243	/* Disable hardware page table walking while in guest */
1244	htw_stop();
1245
1246	/*
1247	 * While in guest context we're in the guest's address space, not the
1248	 * host process address space, so we need to be careful not to confuse
1249	 * e.g. cache management IPIs.
1250	 */
1251	kvm_mips_suspend_mm(cpu);
1252
1253	r = vcpu->arch.vcpu_run(run, vcpu);
1254
1255	/* We may have migrated while handling guest exits */
1256	cpu = smp_processor_id();
1257
1258	/* Restore normal Linux process memory map */
1259	check_switch_mmu_context(current->mm);
1260	kvm_mips_resume_mm(cpu);
1261
1262	htw_start();
1263
1264	pagefault_enable();
1265
1266	return r;
1267}
1268
1269static struct kvm_mips_callbacks kvm_trap_emul_callbacks = {
1270	/* exit handlers */
1271	.handle_cop_unusable = kvm_trap_emul_handle_cop_unusable,
1272	.handle_tlb_mod = kvm_trap_emul_handle_tlb_mod,
1273	.handle_tlb_st_miss = kvm_trap_emul_handle_tlb_st_miss,
1274	.handle_tlb_ld_miss = kvm_trap_emul_handle_tlb_ld_miss,
1275	.handle_addr_err_st = kvm_trap_emul_handle_addr_err_st,
1276	.handle_addr_err_ld = kvm_trap_emul_handle_addr_err_ld,
1277	.handle_syscall = kvm_trap_emul_handle_syscall,
1278	.handle_res_inst = kvm_trap_emul_handle_res_inst,
1279	.handle_break = kvm_trap_emul_handle_break,
1280	.handle_trap = kvm_trap_emul_handle_trap,
1281	.handle_msa_fpe = kvm_trap_emul_handle_msa_fpe,
1282	.handle_fpe = kvm_trap_emul_handle_fpe,
1283	.handle_msa_disabled = kvm_trap_emul_handle_msa_disabled,
1284	.handle_guest_exit = kvm_trap_emul_no_handler,
1285
1286	.hardware_enable = kvm_trap_emul_hardware_enable,
1287	.hardware_disable = kvm_trap_emul_hardware_disable,
1288	.check_extension = kvm_trap_emul_check_extension,
1289	.vcpu_init = kvm_trap_emul_vcpu_init,
1290	.vcpu_uninit = kvm_trap_emul_vcpu_uninit,
1291	.vcpu_setup = kvm_trap_emul_vcpu_setup,
1292	.flush_shadow_all = kvm_trap_emul_flush_shadow_all,
1293	.flush_shadow_memslot = kvm_trap_emul_flush_shadow_memslot,
1294	.gva_to_gpa = kvm_trap_emul_gva_to_gpa_cb,
1295	.queue_timer_int = kvm_mips_queue_timer_int_cb,
1296	.dequeue_timer_int = kvm_mips_dequeue_timer_int_cb,
1297	.queue_io_int = kvm_mips_queue_io_int_cb,
1298	.dequeue_io_int = kvm_mips_dequeue_io_int_cb,
1299	.irq_deliver = kvm_mips_irq_deliver_cb,
1300	.irq_clear = kvm_mips_irq_clear_cb,
1301	.num_regs = kvm_trap_emul_num_regs,
1302	.copy_reg_indices = kvm_trap_emul_copy_reg_indices,
1303	.get_one_reg = kvm_trap_emul_get_one_reg,
1304	.set_one_reg = kvm_trap_emul_set_one_reg,
1305	.vcpu_load = kvm_trap_emul_vcpu_load,
1306	.vcpu_put = kvm_trap_emul_vcpu_put,
1307	.vcpu_run = kvm_trap_emul_vcpu_run,
1308	.vcpu_reenter = kvm_trap_emul_vcpu_reenter,
1309};
1310
1311int kvm_mips_emulation_init(struct kvm_mips_callbacks **install_callbacks)
1312{
1313	*install_callbacks = &kvm_trap_emul_callbacks;
1314	return 0;
1315}