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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	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
  71	u32 cause = vcpu->arch.host_cp0_cause;
  72	enum emulation_result er = EMULATE_DONE;
  73	int ret = RESUME_GUEST;
  74
  75	if (((cause & CAUSEF_CE) >> CAUSEB_CE) == 1) {
  76		/* FPU Unusable */
  77		if (!kvm_mips_guest_has_fpu(&vcpu->arch) ||
  78		    (kvm_read_c0_guest_status(cop0) & ST0_CU1) == 0) {
  79			/*
  80			 * Unusable/no FPU in guest:
  81			 * deliver guest COP1 Unusable Exception
  82			 */
  83			er = kvm_mips_emulate_fpu_exc(cause, opc, vcpu);
  84		} else {
  85			/* Restore FPU state */
  86			kvm_own_fpu(vcpu);
  87			er = EMULATE_DONE;
  88		}
  89	} else {
  90		er = kvm_mips_emulate_inst(cause, opc, vcpu);
  91	}
  92
  93	switch (er) {
  94	case EMULATE_DONE:
  95		ret = RESUME_GUEST;
  96		break;
  97
  98	case EMULATE_FAIL:
  99		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 100		ret = RESUME_HOST;
 101		break;
 102
 103	case EMULATE_WAIT:
 104		vcpu->run->exit_reason = KVM_EXIT_INTR;
 105		ret = RESUME_HOST;
 106		break;
 107
 108	case EMULATE_HYPERCALL:
 109		ret = kvm_mips_handle_hypcall(vcpu);
 110		break;
 111
 112	default:
 113		BUG();
 114	}
 115	return ret;
 116}
 117
 118static int kvm_mips_bad_load(u32 cause, u32 *opc, struct kvm_vcpu *vcpu)
 119{
 120	enum emulation_result er;
 121	union mips_instruction inst;
 122	int err;
 123
 124	/* A code fetch fault doesn't count as an MMIO */
 125	if (kvm_is_ifetch_fault(&vcpu->arch)) {
 126		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 127		return RESUME_HOST;
 128	}
 129
 130	/* Fetch the instruction. */
 131	if (cause & CAUSEF_BD)
 132		opc += 1;
 133	err = kvm_get_badinstr(opc, vcpu, &inst.word);
 134	if (err) {
 135		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 136		return RESUME_HOST;
 137	}
 138
 139	/* Emulate the load */
 140	er = kvm_mips_emulate_load(inst, cause, vcpu);
 141	if (er == EMULATE_FAIL) {
 142		kvm_err("Emulate load from MMIO space failed\n");
 143		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 144	} else {
 145		vcpu->run->exit_reason = KVM_EXIT_MMIO;
 146	}
 147	return RESUME_HOST;
 148}
 149
 150static int kvm_mips_bad_store(u32 cause, u32 *opc, struct kvm_vcpu *vcpu)
 151{
 152	enum emulation_result er;
 153	union mips_instruction inst;
 154	int err;
 155
 156	/* Fetch the instruction. */
 157	if (cause & CAUSEF_BD)
 158		opc += 1;
 159	err = kvm_get_badinstr(opc, vcpu, &inst.word);
 160	if (err) {
 161		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 162		return RESUME_HOST;
 163	}
 164
 165	/* Emulate the store */
 166	er = kvm_mips_emulate_store(inst, cause, vcpu);
 167	if (er == EMULATE_FAIL) {
 168		kvm_err("Emulate store to MMIO space failed\n");
 169		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 170	} else {
 171		vcpu->run->exit_reason = KVM_EXIT_MMIO;
 172	}
 173	return RESUME_HOST;
 174}
 175
 176static int kvm_mips_bad_access(u32 cause, u32 *opc,
 177			       struct kvm_vcpu *vcpu, bool store)
 178{
 179	if (store)
 180		return kvm_mips_bad_store(cause, opc, vcpu);
 181	else
 182		return kvm_mips_bad_load(cause, opc, vcpu);
 183}
 184
 185static int kvm_trap_emul_handle_tlb_mod(struct kvm_vcpu *vcpu)
 186{
 187	struct mips_coproc *cop0 = vcpu->arch.cop0;
 188	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
 189	unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
 190	u32 cause = vcpu->arch.host_cp0_cause;
 191	struct kvm_mips_tlb *tlb;
 192	unsigned long entryhi;
 193	int index;
 194
 195	if (KVM_GUEST_KSEGX(badvaddr) < KVM_GUEST_KSEG0
 196	    || KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG23) {
 197		/*
 198		 * First find the mapping in the guest TLB. If the failure to
 199		 * write was due to the guest TLB, it should be up to the guest
 200		 * to handle it.
 201		 */
 202		entryhi = (badvaddr & VPN2_MASK) |
 203			  (kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID);
 204		index = kvm_mips_guest_tlb_lookup(vcpu, entryhi);
 205
 206		/*
 207		 * These should never happen.
 208		 * They would indicate stale host TLB entries.
 209		 */
 210		if (unlikely(index < 0)) {
 211			vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 212			return RESUME_HOST;
 213		}
 214		tlb = vcpu->arch.guest_tlb + index;
 215		if (unlikely(!TLB_IS_VALID(*tlb, badvaddr))) {
 216			vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 217			return RESUME_HOST;
 218		}
 219
 220		/*
 221		 * Guest entry not dirty? That would explain the TLB modified
 222		 * exception. Relay that on to the guest so it can handle it.
 223		 */
 224		if (!TLB_IS_DIRTY(*tlb, badvaddr)) {
 225			kvm_mips_emulate_tlbmod(cause, opc, vcpu);
 226			return RESUME_GUEST;
 227		}
 228
 229		if (kvm_mips_handle_mapped_seg_tlb_fault(vcpu, tlb, badvaddr,
 230							 true))
 231			/* Not writable, needs handling as MMIO */
 232			return kvm_mips_bad_store(cause, opc, vcpu);
 233		return RESUME_GUEST;
 234	} else if (KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG0) {
 235		if (kvm_mips_handle_kseg0_tlb_fault(badvaddr, vcpu, true) < 0)
 236			/* Not writable, needs handling as MMIO */
 237			return kvm_mips_bad_store(cause, opc, vcpu);
 238		return RESUME_GUEST;
 239	} else {
 240		/* host kernel addresses are all handled as MMIO */
 241		return kvm_mips_bad_store(cause, opc, vcpu);
 242	}
 243}
 244
 245static int kvm_trap_emul_handle_tlb_miss(struct kvm_vcpu *vcpu, bool store)
 246{
 247	struct kvm_run *run = vcpu->run;
 248	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
 249	unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
 250	u32 cause = vcpu->arch.host_cp0_cause;
 251	enum emulation_result er = EMULATE_DONE;
 252	int ret = RESUME_GUEST;
 253
 254	if (((badvaddr & PAGE_MASK) == KVM_GUEST_COMMPAGE_ADDR)
 255	    && KVM_GUEST_KERNEL_MODE(vcpu)) {
 256		if (kvm_mips_handle_commpage_tlb_fault(badvaddr, vcpu) < 0) {
 257			run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 258			ret = RESUME_HOST;
 259		}
 260	} else if (KVM_GUEST_KSEGX(badvaddr) < KVM_GUEST_KSEG0
 261		   || KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG23) {
 262		kvm_debug("USER ADDR TLB %s fault: cause %#x, PC: %p, BadVaddr: %#lx\n",
 263			  store ? "ST" : "LD", cause, opc, badvaddr);
 264
 265		/*
 266		 * User Address (UA) fault, this could happen if
 267		 * (1) TLB entry not present/valid in both Guest and shadow host
 268		 *     TLBs, in this case we pass on the fault to the guest
 269		 *     kernel and let it handle it.
 270		 * (2) TLB entry is present in the Guest TLB but not in the
 271		 *     shadow, in this case we inject the TLB from the Guest TLB
 272		 *     into the shadow host TLB
 273		 */
 274
 275		er = kvm_mips_handle_tlbmiss(cause, opc, vcpu, store);
 276		if (er == EMULATE_DONE)
 277			ret = RESUME_GUEST;
 278		else {
 279			run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 280			ret = RESUME_HOST;
 281		}
 282	} else if (KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG0) {
 283		/*
 284		 * All KSEG0 faults are handled by KVM, as the guest kernel does
 285		 * not expect to ever get them
 286		 */
 287		if (kvm_mips_handle_kseg0_tlb_fault(badvaddr, vcpu, store) < 0)
 288			ret = kvm_mips_bad_access(cause, opc, vcpu, store);
 289	} else if (KVM_GUEST_KERNEL_MODE(vcpu)
 290		   && (KSEGX(badvaddr) == CKSEG0 || KSEGX(badvaddr) == CKSEG1)) {
 291		/*
 292		 * With EVA we may get a TLB exception instead of an address
 293		 * error when the guest performs MMIO to KSeg1 addresses.
 294		 */
 295		ret = kvm_mips_bad_access(cause, opc, vcpu, store);
 296	} else {
 297		kvm_err("Illegal TLB %s fault address , cause %#x, PC: %p, BadVaddr: %#lx\n",
 298			store ? "ST" : "LD", cause, opc, badvaddr);
 299		kvm_mips_dump_host_tlbs();
 300		kvm_arch_vcpu_dump_regs(vcpu);
 301		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 302		ret = RESUME_HOST;
 303	}
 304	return ret;
 305}
 306
 307static int kvm_trap_emul_handle_tlb_st_miss(struct kvm_vcpu *vcpu)
 308{
 309	return kvm_trap_emul_handle_tlb_miss(vcpu, true);
 310}
 311
 312static int kvm_trap_emul_handle_tlb_ld_miss(struct kvm_vcpu *vcpu)
 313{
 314	return kvm_trap_emul_handle_tlb_miss(vcpu, false);
 315}
 316
 317static int kvm_trap_emul_handle_addr_err_st(struct kvm_vcpu *vcpu)
 318{
 319	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
 320	unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
 321	u32 cause = vcpu->arch.host_cp0_cause;
 322	int ret = RESUME_GUEST;
 323
 324	if (KVM_GUEST_KERNEL_MODE(vcpu)
 325	    && (KSEGX(badvaddr) == CKSEG0 || KSEGX(badvaddr) == CKSEG1)) {
 326		ret = kvm_mips_bad_store(cause, opc, vcpu);
 327	} else {
 328		kvm_err("Address Error (STORE): cause %#x, PC: %p, BadVaddr: %#lx\n",
 329			cause, opc, badvaddr);
 330		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 331		ret = RESUME_HOST;
 332	}
 333	return ret;
 334}
 335
 336static int kvm_trap_emul_handle_addr_err_ld(struct kvm_vcpu *vcpu)
 337{
 338	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
 339	unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
 340	u32 cause = vcpu->arch.host_cp0_cause;
 341	int ret = RESUME_GUEST;
 342
 343	if (KSEGX(badvaddr) == CKSEG0 || KSEGX(badvaddr) == CKSEG1) {
 344		ret = kvm_mips_bad_load(cause, opc, vcpu);
 345	} else {
 346		kvm_err("Address Error (LOAD): cause %#x, PC: %p, BadVaddr: %#lx\n",
 347			cause, opc, badvaddr);
 348		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 349		ret = RESUME_HOST;
 350	}
 351	return ret;
 352}
 353
 354static int kvm_trap_emul_handle_syscall(struct kvm_vcpu *vcpu)
 355{
 356	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
 357	u32 cause = vcpu->arch.host_cp0_cause;
 358	enum emulation_result er = EMULATE_DONE;
 359	int ret = RESUME_GUEST;
 360
 361	er = kvm_mips_emulate_syscall(cause, opc, vcpu);
 362	if (er == EMULATE_DONE)
 363		ret = RESUME_GUEST;
 364	else {
 365		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 366		ret = RESUME_HOST;
 367	}
 368	return ret;
 369}
 370
 371static int kvm_trap_emul_handle_res_inst(struct kvm_vcpu *vcpu)
 372{
 373	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
 374	u32 cause = vcpu->arch.host_cp0_cause;
 375	enum emulation_result er = EMULATE_DONE;
 376	int ret = RESUME_GUEST;
 377
 378	er = kvm_mips_handle_ri(cause, opc, vcpu);
 379	if (er == EMULATE_DONE)
 380		ret = RESUME_GUEST;
 381	else {
 382		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 383		ret = RESUME_HOST;
 384	}
 385	return ret;
 386}
 387
 388static int kvm_trap_emul_handle_break(struct kvm_vcpu *vcpu)
 389{
 390	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
 391	u32 cause = vcpu->arch.host_cp0_cause;
 392	enum emulation_result er = EMULATE_DONE;
 393	int ret = RESUME_GUEST;
 394
 395	er = kvm_mips_emulate_bp_exc(cause, opc, vcpu);
 396	if (er == EMULATE_DONE)
 397		ret = RESUME_GUEST;
 398	else {
 399		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 400		ret = RESUME_HOST;
 401	}
 402	return ret;
 403}
 404
 405static int kvm_trap_emul_handle_trap(struct kvm_vcpu *vcpu)
 406{
 407	u32 __user *opc = (u32 __user *)vcpu->arch.pc;
 408	u32 cause = vcpu->arch.host_cp0_cause;
 409	enum emulation_result er = EMULATE_DONE;
 410	int ret = RESUME_GUEST;
 411
 412	er = kvm_mips_emulate_trap_exc(cause, opc, vcpu);
 413	if (er == EMULATE_DONE) {
 414		ret = RESUME_GUEST;
 415	} else {
 416		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 417		ret = RESUME_HOST;
 418	}
 419	return ret;
 420}
 421
 422static int kvm_trap_emul_handle_msa_fpe(struct kvm_vcpu *vcpu)
 423{
 424	u32 __user *opc = (u32 __user *)vcpu->arch.pc;
 425	u32 cause = vcpu->arch.host_cp0_cause;
 426	enum emulation_result er = EMULATE_DONE;
 427	int ret = RESUME_GUEST;
 428
 429	er = kvm_mips_emulate_msafpe_exc(cause, opc, vcpu);
 430	if (er == EMULATE_DONE) {
 431		ret = RESUME_GUEST;
 432	} else {
 433		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 434		ret = RESUME_HOST;
 435	}
 436	return ret;
 437}
 438
 439static int kvm_trap_emul_handle_fpe(struct kvm_vcpu *vcpu)
 440{
 441	u32 __user *opc = (u32 __user *)vcpu->arch.pc;
 442	u32 cause = vcpu->arch.host_cp0_cause;
 443	enum emulation_result er = EMULATE_DONE;
 444	int ret = RESUME_GUEST;
 445
 446	er = kvm_mips_emulate_fpe_exc(cause, opc, vcpu);
 447	if (er == EMULATE_DONE) {
 448		ret = RESUME_GUEST;
 449	} else {
 450		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 451		ret = RESUME_HOST;
 452	}
 453	return ret;
 454}
 455
 456/**
 457 * kvm_trap_emul_handle_msa_disabled() - Guest used MSA while disabled in root.
 458 * @vcpu:	Virtual CPU context.
 459 *
 460 * Handle when the guest attempts to use MSA when it is disabled.
 461 */
 462static int kvm_trap_emul_handle_msa_disabled(struct kvm_vcpu *vcpu)
 463{
 464	struct mips_coproc *cop0 = vcpu->arch.cop0;
 465	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
 466	u32 cause = vcpu->arch.host_cp0_cause;
 467	enum emulation_result er = EMULATE_DONE;
 468	int ret = RESUME_GUEST;
 469
 470	if (!kvm_mips_guest_has_msa(&vcpu->arch) ||
 471	    (kvm_read_c0_guest_status(cop0) & (ST0_CU1 | ST0_FR)) == ST0_CU1) {
 472		/*
 473		 * No MSA in guest, or FPU enabled and not in FR=1 mode,
 474		 * guest reserved instruction exception
 475		 */
 476		er = kvm_mips_emulate_ri_exc(cause, opc, vcpu);
 477	} else if (!(kvm_read_c0_guest_config5(cop0) & MIPS_CONF5_MSAEN)) {
 478		/* MSA disabled by guest, guest MSA disabled exception */
 479		er = kvm_mips_emulate_msadis_exc(cause, opc, vcpu);
 480	} else {
 481		/* Restore MSA/FPU state */
 482		kvm_own_msa(vcpu);
 483		er = EMULATE_DONE;
 484	}
 485
 486	switch (er) {
 487	case EMULATE_DONE:
 488		ret = RESUME_GUEST;
 489		break;
 490
 491	case EMULATE_FAIL:
 492		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
 493		ret = RESUME_HOST;
 494		break;
 495
 496	default:
 497		BUG();
 498	}
 499	return ret;
 500}
 501
 502static int kvm_trap_emul_hardware_enable(void)
 503{
 504	return 0;
 505}
 506
 507static void kvm_trap_emul_hardware_disable(void)
 508{
 509}
 510
 511static int kvm_trap_emul_check_extension(struct kvm *kvm, long ext)
 512{
 513	int r;
 514
 515	switch (ext) {
 516	case KVM_CAP_MIPS_TE:
 517		r = 1;
 518		break;
 519	case KVM_CAP_IOEVENTFD:
 520		r = 1;
 521		break;
 522	default:
 523		r = 0;
 524		break;
 525	}
 526
 527	return r;
 528}
 529
 530static int kvm_trap_emul_vcpu_init(struct kvm_vcpu *vcpu)
 531{
 532	struct mm_struct *kern_mm = &vcpu->arch.guest_kernel_mm;
 533	struct mm_struct *user_mm = &vcpu->arch.guest_user_mm;
 534
 535	/*
 536	 * Allocate GVA -> HPA page tables.
 537	 * MIPS doesn't use the mm_struct pointer argument.
 538	 */
 539	kern_mm->pgd = pgd_alloc(kern_mm);
 540	if (!kern_mm->pgd)
 541		return -ENOMEM;
 542
 543	user_mm->pgd = pgd_alloc(user_mm);
 544	if (!user_mm->pgd) {
 545		pgd_free(kern_mm, kern_mm->pgd);
 546		return -ENOMEM;
 547	}
 548
 549	return 0;
 550}
 551
 552static void kvm_mips_emul_free_gva_pt(pgd_t *pgd)
 553{
 554	/* Don't free host kernel page tables copied from init_mm.pgd */
 555	const unsigned long end = 0x80000000;
 556	unsigned long pgd_va, pud_va, pmd_va;
 557	p4d_t *p4d;
 558	pud_t *pud;
 559	pmd_t *pmd;
 560	pte_t *pte;
 561	int i, j, k;
 562
 563	for (i = 0; i < USER_PTRS_PER_PGD; i++) {
 564		if (pgd_none(pgd[i]))
 565			continue;
 566
 567		pgd_va = (unsigned long)i << PGDIR_SHIFT;
 568		if (pgd_va >= end)
 569			break;
 570		p4d = p4d_offset(pgd, 0);
 571		pud = pud_offset(p4d + i, 0);
 572		for (j = 0; j < PTRS_PER_PUD; j++) {
 573			if (pud_none(pud[j]))
 574				continue;
 575
 576			pud_va = pgd_va | ((unsigned long)j << PUD_SHIFT);
 577			if (pud_va >= end)
 578				break;
 579			pmd = pmd_offset(pud + j, 0);
 580			for (k = 0; k < PTRS_PER_PMD; k++) {
 581				if (pmd_none(pmd[k]))
 582					continue;
 583
 584				pmd_va = pud_va | (k << PMD_SHIFT);
 585				if (pmd_va >= end)
 586					break;
 587				pte = pte_offset_kernel(pmd + k, 0);
 588				pte_free_kernel(NULL, pte);
 589			}
 590			pmd_free(NULL, pmd);
 591		}
 592		pud_free(NULL, pud);
 593	}
 594	pgd_free(NULL, pgd);
 595}
 596
 597static void kvm_trap_emul_vcpu_uninit(struct kvm_vcpu *vcpu)
 598{
 599	kvm_mips_emul_free_gva_pt(vcpu->arch.guest_kernel_mm.pgd);
 600	kvm_mips_emul_free_gva_pt(vcpu->arch.guest_user_mm.pgd);
 601}
 602
 603static int kvm_trap_emul_vcpu_setup(struct kvm_vcpu *vcpu)
 604{
 605	struct mips_coproc *cop0 = vcpu->arch.cop0;
 606	u32 config, config1;
 607	int vcpu_id = vcpu->vcpu_id;
 608
 609	/* Start off the timer at 100 MHz */
 610	kvm_mips_init_count(vcpu, 100*1000*1000);
 611
 612	/*
 613	 * Arch specific stuff, set up config registers properly so that the
 614	 * guest will come up as expected
 615	 */
 616#ifndef CONFIG_CPU_MIPSR6
 617	/* r2-r5, simulate a MIPS 24kc */
 618	kvm_write_c0_guest_prid(cop0, 0x00019300);
 619#else
 620	/* r6+, simulate a generic QEMU machine */
 621	kvm_write_c0_guest_prid(cop0, 0x00010000);
 622#endif
 623	/*
 624	 * Have config1, Cacheable, noncoherent, write-back, write allocate.
 625	 * Endianness, arch revision & virtually tagged icache should match
 626	 * host.
 627	 */
 628	config = read_c0_config() & MIPS_CONF_AR;
 629	config |= MIPS_CONF_M | CONF_CM_CACHABLE_NONCOHERENT | MIPS_CONF_MT_TLB;
 630#ifdef CONFIG_CPU_BIG_ENDIAN
 631	config |= CONF_BE;
 632#endif
 633	if (cpu_has_vtag_icache)
 634		config |= MIPS_CONF_VI;
 635	kvm_write_c0_guest_config(cop0, config);
 636
 637	/* Read the cache characteristics from the host Config1 Register */
 638	config1 = (read_c0_config1() & ~0x7f);
 639
 640	/* DCache line size not correctly reported in Config1 on Octeon CPUs */
 641	if (cpu_dcache_line_size()) {
 642		config1 &= ~MIPS_CONF1_DL;
 643		config1 |= ((ilog2(cpu_dcache_line_size()) - 1) <<
 644			    MIPS_CONF1_DL_SHF) & MIPS_CONF1_DL;
 645	}
 646
 647	/* Set up MMU size */
 648	config1 &= ~(0x3f << 25);
 649	config1 |= ((KVM_MIPS_GUEST_TLB_SIZE - 1) << 25);
 650
 651	/* We unset some bits that we aren't emulating */
 652	config1 &= ~(MIPS_CONF1_C2 | MIPS_CONF1_MD | MIPS_CONF1_PC |
 653		     MIPS_CONF1_WR | MIPS_CONF1_CA);
 654	kvm_write_c0_guest_config1(cop0, config1);
 655
 656	/* Have config3, no tertiary/secondary caches implemented */
 657	kvm_write_c0_guest_config2(cop0, MIPS_CONF_M);
 658	/* MIPS_CONF_M | (read_c0_config2() & 0xfff) */
 659
 660	/* Have config4, UserLocal */
 661	kvm_write_c0_guest_config3(cop0, MIPS_CONF_M | MIPS_CONF3_ULRI);
 662
 663	/* Have config5 */
 664	kvm_write_c0_guest_config4(cop0, MIPS_CONF_M);
 665
 666	/* No config6 */
 667	kvm_write_c0_guest_config5(cop0, 0);
 668
 669	/* Set Wait IE/IXMT Ignore in Config7, IAR, AR */
 670	kvm_write_c0_guest_config7(cop0, (MIPS_CONF7_WII) | (1 << 10));
 671
 672	/* Status */
 673	kvm_write_c0_guest_status(cop0, ST0_BEV | ST0_ERL);
 674
 675	/*
 676	 * Setup IntCtl defaults, compatibility mode for timer interrupts (HW5)
 677	 */
 678	kvm_write_c0_guest_intctl(cop0, 0xFC000000);
 679
 680	/* Put in vcpu id as CPUNum into Ebase Reg to handle SMP Guests */
 681	kvm_write_c0_guest_ebase(cop0, KVM_GUEST_KSEG0 |
 682				       (vcpu_id & MIPS_EBASE_CPUNUM));
 683
 684	/* Put PC at guest reset vector */
 685	vcpu->arch.pc = KVM_GUEST_CKSEG1ADDR(0x1fc00000);
 686
 687	return 0;
 688}
 689
 690static void kvm_trap_emul_flush_shadow_all(struct kvm *kvm)
 691{
 692	/* Flush GVA page tables and invalidate GVA ASIDs on all VCPUs */
 693	kvm_flush_remote_tlbs(kvm);
 694}
 695
 696static void kvm_trap_emul_flush_shadow_memslot(struct kvm *kvm,
 697					const struct kvm_memory_slot *slot)
 698{
 699	kvm_trap_emul_flush_shadow_all(kvm);
 700}
 701
 702static u64 kvm_trap_emul_get_one_regs[] = {
 703	KVM_REG_MIPS_CP0_INDEX,
 704	KVM_REG_MIPS_CP0_ENTRYLO0,
 705	KVM_REG_MIPS_CP0_ENTRYLO1,
 706	KVM_REG_MIPS_CP0_CONTEXT,
 707	KVM_REG_MIPS_CP0_USERLOCAL,
 708	KVM_REG_MIPS_CP0_PAGEMASK,
 709	KVM_REG_MIPS_CP0_WIRED,
 710	KVM_REG_MIPS_CP0_HWRENA,
 711	KVM_REG_MIPS_CP0_BADVADDR,
 712	KVM_REG_MIPS_CP0_COUNT,
 713	KVM_REG_MIPS_CP0_ENTRYHI,
 714	KVM_REG_MIPS_CP0_COMPARE,
 715	KVM_REG_MIPS_CP0_STATUS,
 716	KVM_REG_MIPS_CP0_INTCTL,
 717	KVM_REG_MIPS_CP0_CAUSE,
 718	KVM_REG_MIPS_CP0_EPC,
 719	KVM_REG_MIPS_CP0_PRID,
 720	KVM_REG_MIPS_CP0_EBASE,
 721	KVM_REG_MIPS_CP0_CONFIG,
 722	KVM_REG_MIPS_CP0_CONFIG1,
 723	KVM_REG_MIPS_CP0_CONFIG2,
 724	KVM_REG_MIPS_CP0_CONFIG3,
 725	KVM_REG_MIPS_CP0_CONFIG4,
 726	KVM_REG_MIPS_CP0_CONFIG5,
 727	KVM_REG_MIPS_CP0_CONFIG7,
 728	KVM_REG_MIPS_CP0_ERROREPC,
 729	KVM_REG_MIPS_CP0_KSCRATCH1,
 730	KVM_REG_MIPS_CP0_KSCRATCH2,
 731	KVM_REG_MIPS_CP0_KSCRATCH3,
 732	KVM_REG_MIPS_CP0_KSCRATCH4,
 733	KVM_REG_MIPS_CP0_KSCRATCH5,
 734	KVM_REG_MIPS_CP0_KSCRATCH6,
 735
 736	KVM_REG_MIPS_COUNT_CTL,
 737	KVM_REG_MIPS_COUNT_RESUME,
 738	KVM_REG_MIPS_COUNT_HZ,
 739};
 740
 741static unsigned long kvm_trap_emul_num_regs(struct kvm_vcpu *vcpu)
 742{
 743	return ARRAY_SIZE(kvm_trap_emul_get_one_regs);
 744}
 745
 746static int kvm_trap_emul_copy_reg_indices(struct kvm_vcpu *vcpu,
 747					  u64 __user *indices)
 748{
 749	if (copy_to_user(indices, kvm_trap_emul_get_one_regs,
 750			 sizeof(kvm_trap_emul_get_one_regs)))
 751		return -EFAULT;
 752	indices += ARRAY_SIZE(kvm_trap_emul_get_one_regs);
 753
 754	return 0;
 755}
 756
 757static int kvm_trap_emul_get_one_reg(struct kvm_vcpu *vcpu,
 758				     const struct kvm_one_reg *reg,
 759				     s64 *v)
 760{
 761	struct mips_coproc *cop0 = vcpu->arch.cop0;
 762
 763	switch (reg->id) {
 764	case KVM_REG_MIPS_CP0_INDEX:
 765		*v = (long)kvm_read_c0_guest_index(cop0);
 766		break;
 767	case KVM_REG_MIPS_CP0_ENTRYLO0:
 768		*v = kvm_read_c0_guest_entrylo0(cop0);
 769		break;
 770	case KVM_REG_MIPS_CP0_ENTRYLO1:
 771		*v = kvm_read_c0_guest_entrylo1(cop0);
 772		break;
 773	case KVM_REG_MIPS_CP0_CONTEXT:
 774		*v = (long)kvm_read_c0_guest_context(cop0);
 775		break;
 776	case KVM_REG_MIPS_CP0_USERLOCAL:
 777		*v = (long)kvm_read_c0_guest_userlocal(cop0);
 778		break;
 779	case KVM_REG_MIPS_CP0_PAGEMASK:
 780		*v = (long)kvm_read_c0_guest_pagemask(cop0);
 781		break;
 782	case KVM_REG_MIPS_CP0_WIRED:
 783		*v = (long)kvm_read_c0_guest_wired(cop0);
 784		break;
 785	case KVM_REG_MIPS_CP0_HWRENA:
 786		*v = (long)kvm_read_c0_guest_hwrena(cop0);
 787		break;
 788	case KVM_REG_MIPS_CP0_BADVADDR:
 789		*v = (long)kvm_read_c0_guest_badvaddr(cop0);
 790		break;
 791	case KVM_REG_MIPS_CP0_ENTRYHI:
 792		*v = (long)kvm_read_c0_guest_entryhi(cop0);
 793		break;
 794	case KVM_REG_MIPS_CP0_COMPARE:
 795		*v = (long)kvm_read_c0_guest_compare(cop0);
 796		break;
 797	case KVM_REG_MIPS_CP0_STATUS:
 798		*v = (long)kvm_read_c0_guest_status(cop0);
 799		break;
 800	case KVM_REG_MIPS_CP0_INTCTL:
 801		*v = (long)kvm_read_c0_guest_intctl(cop0);
 802		break;
 803	case KVM_REG_MIPS_CP0_CAUSE:
 804		*v = (long)kvm_read_c0_guest_cause(cop0);
 805		break;
 806	case KVM_REG_MIPS_CP0_EPC:
 807		*v = (long)kvm_read_c0_guest_epc(cop0);
 808		break;
 809	case KVM_REG_MIPS_CP0_PRID:
 810		*v = (long)kvm_read_c0_guest_prid(cop0);
 811		break;
 812	case KVM_REG_MIPS_CP0_EBASE:
 813		*v = (long)kvm_read_c0_guest_ebase(cop0);
 814		break;
 815	case KVM_REG_MIPS_CP0_CONFIG:
 816		*v = (long)kvm_read_c0_guest_config(cop0);
 817		break;
 818	case KVM_REG_MIPS_CP0_CONFIG1:
 819		*v = (long)kvm_read_c0_guest_config1(cop0);
 820		break;
 821	case KVM_REG_MIPS_CP0_CONFIG2:
 822		*v = (long)kvm_read_c0_guest_config2(cop0);
 823		break;
 824	case KVM_REG_MIPS_CP0_CONFIG3:
 825		*v = (long)kvm_read_c0_guest_config3(cop0);
 826		break;
 827	case KVM_REG_MIPS_CP0_CONFIG4:
 828		*v = (long)kvm_read_c0_guest_config4(cop0);
 829		break;
 830	case KVM_REG_MIPS_CP0_CONFIG5:
 831		*v = (long)kvm_read_c0_guest_config5(cop0);
 832		break;
 833	case KVM_REG_MIPS_CP0_CONFIG7:
 834		*v = (long)kvm_read_c0_guest_config7(cop0);
 835		break;
 836	case KVM_REG_MIPS_CP0_COUNT:
 837		*v = kvm_mips_read_count(vcpu);
 838		break;
 839	case KVM_REG_MIPS_COUNT_CTL:
 840		*v = vcpu->arch.count_ctl;
 841		break;
 842	case KVM_REG_MIPS_COUNT_RESUME:
 843		*v = ktime_to_ns(vcpu->arch.count_resume);
 844		break;
 845	case KVM_REG_MIPS_COUNT_HZ:
 846		*v = vcpu->arch.count_hz;
 847		break;
 848	case KVM_REG_MIPS_CP0_ERROREPC:
 849		*v = (long)kvm_read_c0_guest_errorepc(cop0);
 850		break;
 851	case KVM_REG_MIPS_CP0_KSCRATCH1:
 852		*v = (long)kvm_read_c0_guest_kscratch1(cop0);
 853		break;
 854	case KVM_REG_MIPS_CP0_KSCRATCH2:
 855		*v = (long)kvm_read_c0_guest_kscratch2(cop0);
 856		break;
 857	case KVM_REG_MIPS_CP0_KSCRATCH3:
 858		*v = (long)kvm_read_c0_guest_kscratch3(cop0);
 859		break;
 860	case KVM_REG_MIPS_CP0_KSCRATCH4:
 861		*v = (long)kvm_read_c0_guest_kscratch4(cop0);
 862		break;
 863	case KVM_REG_MIPS_CP0_KSCRATCH5:
 864		*v = (long)kvm_read_c0_guest_kscratch5(cop0);
 865		break;
 866	case KVM_REG_MIPS_CP0_KSCRATCH6:
 867		*v = (long)kvm_read_c0_guest_kscratch6(cop0);
 868		break;
 869	default:
 870		return -EINVAL;
 871	}
 872	return 0;
 873}
 874
 875static int kvm_trap_emul_set_one_reg(struct kvm_vcpu *vcpu,
 876				     const struct kvm_one_reg *reg,
 877				     s64 v)
 878{
 879	struct mips_coproc *cop0 = vcpu->arch.cop0;
 880	int ret = 0;
 881	unsigned int cur, change;
 882
 883	switch (reg->id) {
 884	case KVM_REG_MIPS_CP0_INDEX:
 885		kvm_write_c0_guest_index(cop0, v);
 886		break;
 887	case KVM_REG_MIPS_CP0_ENTRYLO0:
 888		kvm_write_c0_guest_entrylo0(cop0, v);
 889		break;
 890	case KVM_REG_MIPS_CP0_ENTRYLO1:
 891		kvm_write_c0_guest_entrylo1(cop0, v);
 892		break;
 893	case KVM_REG_MIPS_CP0_CONTEXT:
 894		kvm_write_c0_guest_context(cop0, v);
 895		break;
 896	case KVM_REG_MIPS_CP0_USERLOCAL:
 897		kvm_write_c0_guest_userlocal(cop0, v);
 898		break;
 899	case KVM_REG_MIPS_CP0_PAGEMASK:
 900		kvm_write_c0_guest_pagemask(cop0, v);
 901		break;
 902	case KVM_REG_MIPS_CP0_WIRED:
 903		kvm_write_c0_guest_wired(cop0, v);
 904		break;
 905	case KVM_REG_MIPS_CP0_HWRENA:
 906		kvm_write_c0_guest_hwrena(cop0, v);
 907		break;
 908	case KVM_REG_MIPS_CP0_BADVADDR:
 909		kvm_write_c0_guest_badvaddr(cop0, v);
 910		break;
 911	case KVM_REG_MIPS_CP0_ENTRYHI:
 912		kvm_write_c0_guest_entryhi(cop0, v);
 913		break;
 914	case KVM_REG_MIPS_CP0_STATUS:
 915		kvm_write_c0_guest_status(cop0, v);
 916		break;
 917	case KVM_REG_MIPS_CP0_INTCTL:
 918		/* No VInt, so no VS, read-only for now */
 919		break;
 920	case KVM_REG_MIPS_CP0_EPC:
 921		kvm_write_c0_guest_epc(cop0, v);
 922		break;
 923	case KVM_REG_MIPS_CP0_PRID:
 924		kvm_write_c0_guest_prid(cop0, v);
 925		break;
 926	case KVM_REG_MIPS_CP0_EBASE:
 927		/*
 928		 * Allow core number to be written, but the exception base must
 929		 * remain in guest KSeg0.
 930		 */
 931		kvm_change_c0_guest_ebase(cop0, 0x1ffff000 | MIPS_EBASE_CPUNUM,
 932					  v);
 933		break;
 934	case KVM_REG_MIPS_CP0_COUNT:
 935		kvm_mips_write_count(vcpu, v);
 936		break;
 937	case KVM_REG_MIPS_CP0_COMPARE:
 938		kvm_mips_write_compare(vcpu, v, false);
 939		break;
 940	case KVM_REG_MIPS_CP0_CAUSE:
 941		/*
 942		 * If the timer is stopped or started (DC bit) it must look
 943		 * atomic with changes to the interrupt pending bits (TI, IRQ5).
 944		 * A timer interrupt should not happen in between.
 945		 */
 946		if ((kvm_read_c0_guest_cause(cop0) ^ v) & CAUSEF_DC) {
 947			if (v & CAUSEF_DC) {
 948				/* disable timer first */
 949				kvm_mips_count_disable_cause(vcpu);
 950				kvm_change_c0_guest_cause(cop0, (u32)~CAUSEF_DC,
 951							  v);
 952			} else {
 953				/* enable timer last */
 954				kvm_change_c0_guest_cause(cop0, (u32)~CAUSEF_DC,
 955							  v);
 956				kvm_mips_count_enable_cause(vcpu);
 957			}
 958		} else {
 959			kvm_write_c0_guest_cause(cop0, v);
 960		}
 961		break;
 962	case KVM_REG_MIPS_CP0_CONFIG:
 963		/* read-only for now */
 964		break;
 965	case KVM_REG_MIPS_CP0_CONFIG1:
 966		cur = kvm_read_c0_guest_config1(cop0);
 967		change = (cur ^ v) & kvm_mips_config1_wrmask(vcpu);
 968		if (change) {
 969			v = cur ^ change;
 970			kvm_write_c0_guest_config1(cop0, v);
 971		}
 972		break;
 973	case KVM_REG_MIPS_CP0_CONFIG2:
 974		/* read-only for now */
 975		break;
 976	case KVM_REG_MIPS_CP0_CONFIG3:
 977		cur = kvm_read_c0_guest_config3(cop0);
 978		change = (cur ^ v) & kvm_mips_config3_wrmask(vcpu);
 979		if (change) {
 980			v = cur ^ change;
 981			kvm_write_c0_guest_config3(cop0, v);
 982		}
 983		break;
 984	case KVM_REG_MIPS_CP0_CONFIG4:
 985		cur = kvm_read_c0_guest_config4(cop0);
 986		change = (cur ^ v) & kvm_mips_config4_wrmask(vcpu);
 987		if (change) {
 988			v = cur ^ change;
 989			kvm_write_c0_guest_config4(cop0, v);
 990		}
 991		break;
 992	case KVM_REG_MIPS_CP0_CONFIG5:
 993		cur = kvm_read_c0_guest_config5(cop0);
 994		change = (cur ^ v) & kvm_mips_config5_wrmask(vcpu);
 995		if (change) {
 996			v = cur ^ change;
 997			kvm_write_c0_guest_config5(cop0, v);
 998		}
 999		break;
1000	case KVM_REG_MIPS_CP0_CONFIG7:
1001		/* writes ignored */
1002		break;
1003	case KVM_REG_MIPS_COUNT_CTL:
1004		ret = kvm_mips_set_count_ctl(vcpu, v);
1005		break;
1006	case KVM_REG_MIPS_COUNT_RESUME:
1007		ret = kvm_mips_set_count_resume(vcpu, v);
1008		break;
1009	case KVM_REG_MIPS_COUNT_HZ:
1010		ret = kvm_mips_set_count_hz(vcpu, v);
1011		break;
1012	case KVM_REG_MIPS_CP0_ERROREPC:
1013		kvm_write_c0_guest_errorepc(cop0, v);
1014		break;
1015	case KVM_REG_MIPS_CP0_KSCRATCH1:
1016		kvm_write_c0_guest_kscratch1(cop0, v);
1017		break;
1018	case KVM_REG_MIPS_CP0_KSCRATCH2:
1019		kvm_write_c0_guest_kscratch2(cop0, v);
1020		break;
1021	case KVM_REG_MIPS_CP0_KSCRATCH3:
1022		kvm_write_c0_guest_kscratch3(cop0, v);
1023		break;
1024	case KVM_REG_MIPS_CP0_KSCRATCH4:
1025		kvm_write_c0_guest_kscratch4(cop0, v);
1026		break;
1027	case KVM_REG_MIPS_CP0_KSCRATCH5:
1028		kvm_write_c0_guest_kscratch5(cop0, v);
1029		break;
1030	case KVM_REG_MIPS_CP0_KSCRATCH6:
1031		kvm_write_c0_guest_kscratch6(cop0, v);
1032		break;
1033	default:
1034		return -EINVAL;
1035	}
1036	return ret;
1037}
1038
1039static int kvm_trap_emul_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
1040{
1041	struct mm_struct *kern_mm = &vcpu->arch.guest_kernel_mm;
1042	struct mm_struct *user_mm = &vcpu->arch.guest_user_mm;
1043	struct mm_struct *mm;
1044
1045	/*
1046	 * Were we in guest context? If so, restore the appropriate ASID based
1047	 * on the mode of the Guest (Kernel/User).
1048	 */
1049	if (current->flags & PF_VCPU) {
1050		mm = KVM_GUEST_KERNEL_MODE(vcpu) ? kern_mm : user_mm;
1051		check_switch_mmu_context(mm);
1052		kvm_mips_suspend_mm(cpu);
1053		ehb();
1054	}
1055
1056	return 0;
1057}
1058
1059static int kvm_trap_emul_vcpu_put(struct kvm_vcpu *vcpu, int cpu)
1060{
1061	kvm_lose_fpu(vcpu);
1062
1063	if (current->flags & PF_VCPU) {
1064		/* Restore normal Linux process memory map */
1065		check_switch_mmu_context(current->mm);
1066		kvm_mips_resume_mm(cpu);
1067		ehb();
1068	}
1069
1070	return 0;
1071}
1072
1073static void kvm_trap_emul_check_requests(struct kvm_vcpu *vcpu, int cpu,
1074					 bool reload_asid)
1075{
1076	struct mm_struct *kern_mm = &vcpu->arch.guest_kernel_mm;
1077	struct mm_struct *user_mm = &vcpu->arch.guest_user_mm;
1078	struct mm_struct *mm;
1079	int i;
1080
1081	if (likely(!kvm_request_pending(vcpu)))
1082		return;
1083
1084	if (kvm_check_request(KVM_REQ_TLB_FLUSH, vcpu)) {
1085		/*
1086		 * Both kernel & user GVA mappings must be invalidated. The
1087		 * caller is just about to check whether the ASID is stale
1088		 * anyway so no need to reload it here.
1089		 */
1090		kvm_mips_flush_gva_pt(kern_mm->pgd, KMF_GPA | KMF_KERN);
1091		kvm_mips_flush_gva_pt(user_mm->pgd, KMF_GPA | KMF_USER);
1092		for_each_possible_cpu(i) {
1093			set_cpu_context(i, kern_mm, 0);
1094			set_cpu_context(i, user_mm, 0);
1095		}
1096
1097		/* Generate new ASID for current mode */
1098		if (reload_asid) {
1099			mm = KVM_GUEST_KERNEL_MODE(vcpu) ? kern_mm : user_mm;
1100			get_new_mmu_context(mm);
1101			htw_stop();
1102			write_c0_entryhi(cpu_asid(cpu, mm));
1103			TLBMISS_HANDLER_SETUP_PGD(mm->pgd);
1104			htw_start();
1105		}
1106	}
1107}
1108
1109/**
1110 * kvm_trap_emul_gva_lockless_begin() - Begin lockless access to GVA space.
1111 * @vcpu:	VCPU pointer.
1112 *
1113 * Call before a GVA space access outside of guest mode, to ensure that
1114 * asynchronous TLB flush requests are handled or delayed until completion of
1115 * the GVA access (as indicated by a matching kvm_trap_emul_gva_lockless_end()).
1116 *
1117 * Should be called with IRQs already enabled.
1118 */
1119void kvm_trap_emul_gva_lockless_begin(struct kvm_vcpu *vcpu)
1120{
1121	/* We re-enable IRQs in kvm_trap_emul_gva_lockless_end() */
1122	WARN_ON_ONCE(irqs_disabled());
1123
1124	/*
1125	 * The caller is about to access the GVA space, so we set the mode to
1126	 * force TLB flush requests to send an IPI, and also disable IRQs to
1127	 * delay IPI handling until kvm_trap_emul_gva_lockless_end().
1128	 */
1129	local_irq_disable();
1130
1131	/*
1132	 * Make sure the read of VCPU requests is not reordered ahead of the
1133	 * write to vcpu->mode, or we could miss a TLB flush request while
1134	 * the requester sees the VCPU as outside of guest mode and not needing
1135	 * an IPI.
1136	 */
1137	smp_store_mb(vcpu->mode, READING_SHADOW_PAGE_TABLES);
1138
1139	/*
1140	 * If a TLB flush has been requested (potentially while
1141	 * OUTSIDE_GUEST_MODE and assumed immediately effective), perform it
1142	 * before accessing the GVA space, and be sure to reload the ASID if
1143	 * necessary as it'll be immediately used.
1144	 *
1145	 * TLB flush requests after this check will trigger an IPI due to the
1146	 * mode change above, which will be delayed due to IRQs disabled.
1147	 */
1148	kvm_trap_emul_check_requests(vcpu, smp_processor_id(), true);
1149}
1150
1151/**
1152 * kvm_trap_emul_gva_lockless_end() - End lockless access to GVA space.
1153 * @vcpu:	VCPU pointer.
1154 *
1155 * Called after a GVA space access outside of guest mode. Should have a matching
1156 * call to kvm_trap_emul_gva_lockless_begin().
1157 */
1158void kvm_trap_emul_gva_lockless_end(struct kvm_vcpu *vcpu)
1159{
1160	/*
1161	 * Make sure the write to vcpu->mode is not reordered in front of GVA
1162	 * accesses, or a TLB flush requester may not think it necessary to send
1163	 * an IPI.
1164	 */
1165	smp_store_release(&vcpu->mode, OUTSIDE_GUEST_MODE);
1166
1167	/*
1168	 * Now that the access to GVA space is complete, its safe for pending
1169	 * TLB flush request IPIs to be handled (which indicates completion).
1170	 */
1171	local_irq_enable();
1172}
1173
1174static void kvm_trap_emul_vcpu_reenter(struct kvm_vcpu *vcpu)
1175{
1176	struct mm_struct *kern_mm = &vcpu->arch.guest_kernel_mm;
1177	struct mm_struct *user_mm = &vcpu->arch.guest_user_mm;
1178	struct mm_struct *mm;
1179	struct mips_coproc *cop0 = vcpu->arch.cop0;
1180	int i, cpu = smp_processor_id();
1181	unsigned int gasid;
1182
1183	/*
1184	 * No need to reload ASID, IRQs are disabled already so there's no rush,
1185	 * and we'll check if we need to regenerate below anyway before
1186	 * re-entering the guest.
1187	 */
1188	kvm_trap_emul_check_requests(vcpu, cpu, false);
1189
1190	if (KVM_GUEST_KERNEL_MODE(vcpu)) {
1191		mm = kern_mm;
1192	} else {
1193		mm = user_mm;
1194
1195		/*
1196		 * Lazy host ASID regeneration / PT flush for guest user mode.
1197		 * If the guest ASID has changed since the last guest usermode
1198		 * execution, invalidate the stale TLB entries and flush GVA PT
1199		 * entries too.
1200		 */
1201		gasid = kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID;
1202		if (gasid != vcpu->arch.last_user_gasid) {
1203			kvm_mips_flush_gva_pt(user_mm->pgd, KMF_USER);
1204			for_each_possible_cpu(i)
1205				set_cpu_context(i, user_mm, 0);
1206			vcpu->arch.last_user_gasid = gasid;
1207		}
1208	}
1209
1210	/*
1211	 * Check if ASID is stale. This may happen due to a TLB flush request or
1212	 * a lazy user MM invalidation.
1213	 */
1214	check_mmu_context(mm);
1215}
1216
1217static int kvm_trap_emul_vcpu_run(struct kvm_vcpu *vcpu)
1218{
1219	int cpu = smp_processor_id();
1220	int r;
1221
1222	/* Check if we have any exceptions/interrupts pending */
1223	kvm_mips_deliver_interrupts(vcpu,
1224				    kvm_read_c0_guest_cause(vcpu->arch.cop0));
1225
1226	kvm_trap_emul_vcpu_reenter(vcpu);
1227
1228	/*
1229	 * We use user accessors to access guest memory, but we don't want to
1230	 * invoke Linux page faulting.
1231	 */
1232	pagefault_disable();
1233
1234	/* Disable hardware page table walking while in guest */
1235	htw_stop();
1236
1237	/*
1238	 * While in guest context we're in the guest's address space, not the
1239	 * host process address space, so we need to be careful not to confuse
1240	 * e.g. cache management IPIs.
1241	 */
1242	kvm_mips_suspend_mm(cpu);
1243
1244	r = vcpu->arch.vcpu_run(vcpu->run, vcpu);
1245
1246	/* We may have migrated while handling guest exits */
1247	cpu = smp_processor_id();
1248
1249	/* Restore normal Linux process memory map */
1250	check_switch_mmu_context(current->mm);
1251	kvm_mips_resume_mm(cpu);
1252
1253	htw_start();
1254
1255	pagefault_enable();
1256
1257	return r;
1258}
1259
1260static struct kvm_mips_callbacks kvm_trap_emul_callbacks = {
1261	/* exit handlers */
1262	.handle_cop_unusable = kvm_trap_emul_handle_cop_unusable,
1263	.handle_tlb_mod = kvm_trap_emul_handle_tlb_mod,
1264	.handle_tlb_st_miss = kvm_trap_emul_handle_tlb_st_miss,
1265	.handle_tlb_ld_miss = kvm_trap_emul_handle_tlb_ld_miss,
1266	.handle_addr_err_st = kvm_trap_emul_handle_addr_err_st,
1267	.handle_addr_err_ld = kvm_trap_emul_handle_addr_err_ld,
1268	.handle_syscall = kvm_trap_emul_handle_syscall,
1269	.handle_res_inst = kvm_trap_emul_handle_res_inst,
1270	.handle_break = kvm_trap_emul_handle_break,
1271	.handle_trap = kvm_trap_emul_handle_trap,
1272	.handle_msa_fpe = kvm_trap_emul_handle_msa_fpe,
1273	.handle_fpe = kvm_trap_emul_handle_fpe,
1274	.handle_msa_disabled = kvm_trap_emul_handle_msa_disabled,
1275	.handle_guest_exit = kvm_trap_emul_no_handler,
1276
1277	.hardware_enable = kvm_trap_emul_hardware_enable,
1278	.hardware_disable = kvm_trap_emul_hardware_disable,
1279	.check_extension = kvm_trap_emul_check_extension,
1280	.vcpu_init = kvm_trap_emul_vcpu_init,
1281	.vcpu_uninit = kvm_trap_emul_vcpu_uninit,
1282	.vcpu_setup = kvm_trap_emul_vcpu_setup,
1283	.flush_shadow_all = kvm_trap_emul_flush_shadow_all,
1284	.flush_shadow_memslot = kvm_trap_emul_flush_shadow_memslot,
1285	.gva_to_gpa = kvm_trap_emul_gva_to_gpa_cb,
1286	.queue_timer_int = kvm_mips_queue_timer_int_cb,
1287	.dequeue_timer_int = kvm_mips_dequeue_timer_int_cb,
1288	.queue_io_int = kvm_mips_queue_io_int_cb,
1289	.dequeue_io_int = kvm_mips_dequeue_io_int_cb,
1290	.irq_deliver = kvm_mips_irq_deliver_cb,
1291	.irq_clear = kvm_mips_irq_clear_cb,
1292	.num_regs = kvm_trap_emul_num_regs,
1293	.copy_reg_indices = kvm_trap_emul_copy_reg_indices,
1294	.get_one_reg = kvm_trap_emul_get_one_reg,
1295	.set_one_reg = kvm_trap_emul_set_one_reg,
1296	.vcpu_load = kvm_trap_emul_vcpu_load,
1297	.vcpu_put = kvm_trap_emul_vcpu_put,
1298	.vcpu_run = kvm_trap_emul_vcpu_run,
1299	.vcpu_reenter = kvm_trap_emul_vcpu_reenter,
1300};
1301
1302int kvm_mips_emulation_init(struct kvm_mips_callbacks **install_callbacks)
1303{
1304	*install_callbacks = &kvm_trap_emul_callbacks;
1305	return 0;
1306}