Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1306 insertions, 0 deletions

diff --git a/arch/mips/kvm/trap_emul.c b/arch/mips/kvm/trap_emul.c
new file mode 100644
index 000000000..0788c00d7
--- /dev/null
+++ b/arch/mips/kvm/trap_emul.c
@@ -0,0 +1,1306 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * KVM/MIPS: Deliver/Emulate exceptions to the guest kernel
+ *
+ * Copyright (C) 2012  MIPS Technologies, Inc.  All rights reserved.
+ * Authors: Sanjay Lal <sanjayl@kymasys.com>
+ */
+
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/kvm_host.h>
+#include <linux/log2.h>
+#include <linux/uaccess.h>
+#include <linux/vmalloc.h>
+#include <asm/mmu_context.h>
+#include <asm/pgalloc.h>
+
+#include "interrupt.h"
+
+static gpa_t kvm_trap_emul_gva_to_gpa_cb(gva_t gva)
+{
+	gpa_t gpa;
+	gva_t kseg = KSEGX(gva);
+	gva_t gkseg = KVM_GUEST_KSEGX(gva);
+
+	if ((kseg == CKSEG0) || (kseg == CKSEG1))
+		gpa = CPHYSADDR(gva);
+	else if (gkseg == KVM_GUEST_KSEG0)
+		gpa = KVM_GUEST_CPHYSADDR(gva);
+	else {
+		kvm_err("%s: cannot find GPA for GVA: %#lx\n", __func__, gva);
+		kvm_mips_dump_host_tlbs();
+		gpa = KVM_INVALID_ADDR;
+	}
+
+	kvm_debug("%s: gva %#lx, gpa: %#llx\n", __func__, gva, gpa);
+
+	return gpa;
+}
+
+static int kvm_trap_emul_no_handler(struct kvm_vcpu *vcpu)
+{
+	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
+	u32 cause = vcpu->arch.host_cp0_cause;
+	u32 exccode = (cause & CAUSEF_EXCCODE) >> CAUSEB_EXCCODE;
+	unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
+	u32 inst = 0;
+
+	/*
+	 *  Fetch the instruction.
+	 */
+	if (cause & CAUSEF_BD)
+		opc += 1;
+	kvm_get_badinstr(opc, vcpu, &inst);
+
+	kvm_err("Exception Code: %d not handled @ PC: %p, inst: 0x%08x BadVaddr: %#lx Status: %#x\n",
+		exccode, opc, inst, badvaddr,
+		kvm_read_c0_guest_status(vcpu->arch.cop0));
+	kvm_arch_vcpu_dump_regs(vcpu);
+	vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+	return RESUME_HOST;
+}
+
+static int kvm_trap_emul_handle_cop_unusable(struct kvm_vcpu *vcpu)
+{
+	struct mips_coproc *cop0 = vcpu->arch.cop0;
+	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
+	u32 cause = vcpu->arch.host_cp0_cause;
+	enum emulation_result er = EMULATE_DONE;
+	int ret = RESUME_GUEST;
+
+	if (((cause & CAUSEF_CE) >> CAUSEB_CE) == 1) {
+		/* FPU Unusable */
+		if (!kvm_mips_guest_has_fpu(&vcpu->arch) ||
+		    (kvm_read_c0_guest_status(cop0) & ST0_CU1) == 0) {
+			/*
+			 * Unusable/no FPU in guest:
+			 * deliver guest COP1 Unusable Exception
+			 */
+			er = kvm_mips_emulate_fpu_exc(cause, opc, vcpu);
+		} else {
+			/* Restore FPU state */
+			kvm_own_fpu(vcpu);
+			er = EMULATE_DONE;
+		}
+	} else {
+		er = kvm_mips_emulate_inst(cause, opc, vcpu);
+	}
+
+	switch (er) {
+	case EMULATE_DONE:
+		ret = RESUME_GUEST;
+		break;
+
+	case EMULATE_FAIL:
+		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+		ret = RESUME_HOST;
+		break;
+
+	case EMULATE_WAIT:
+		vcpu->run->exit_reason = KVM_EXIT_INTR;
+		ret = RESUME_HOST;
+		break;
+
+	case EMULATE_HYPERCALL:
+		ret = kvm_mips_handle_hypcall(vcpu);
+		break;
+
+	default:
+		BUG();
+	}
+	return ret;
+}
+
+static int kvm_mips_bad_load(u32 cause, u32 *opc, struct kvm_vcpu *vcpu)
+{
+	enum emulation_result er;
+	union mips_instruction inst;
+	int err;
+
+	/* A code fetch fault doesn't count as an MMIO */
+	if (kvm_is_ifetch_fault(&vcpu->arch)) {
+		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+		return RESUME_HOST;
+	}
+
+	/* Fetch the instruction. */
+	if (cause & CAUSEF_BD)
+		opc += 1;
+	err = kvm_get_badinstr(opc, vcpu, &inst.word);
+	if (err) {
+		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+		return RESUME_HOST;
+	}
+
+	/* Emulate the load */
+	er = kvm_mips_emulate_load(inst, cause, vcpu);
+	if (er == EMULATE_FAIL) {
+		kvm_err("Emulate load from MMIO space failed\n");
+		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+	} else {
+		vcpu->run->exit_reason = KVM_EXIT_MMIO;
+	}
+	return RESUME_HOST;
+}
+
+static int kvm_mips_bad_store(u32 cause, u32 *opc, struct kvm_vcpu *vcpu)
+{
+	enum emulation_result er;
+	union mips_instruction inst;
+	int err;
+
+	/* Fetch the instruction. */
+	if (cause & CAUSEF_BD)
+		opc += 1;
+	err = kvm_get_badinstr(opc, vcpu, &inst.word);
+	if (err) {
+		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+		return RESUME_HOST;
+	}
+
+	/* Emulate the store */
+	er = kvm_mips_emulate_store(inst, cause, vcpu);
+	if (er == EMULATE_FAIL) {
+		kvm_err("Emulate store to MMIO space failed\n");
+		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+	} else {
+		vcpu->run->exit_reason = KVM_EXIT_MMIO;
+	}
+	return RESUME_HOST;
+}
+
+static int kvm_mips_bad_access(u32 cause, u32 *opc,
+			       struct kvm_vcpu *vcpu, bool store)
+{
+	if (store)
+		return kvm_mips_bad_store(cause, opc, vcpu);
+	else
+		return kvm_mips_bad_load(cause, opc, vcpu);
+}
+
+static int kvm_trap_emul_handle_tlb_mod(struct kvm_vcpu *vcpu)
+{
+	struct mips_coproc *cop0 = vcpu->arch.cop0;
+	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
+	unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
+	u32 cause = vcpu->arch.host_cp0_cause;
+	struct kvm_mips_tlb *tlb;
+	unsigned long entryhi;
+	int index;
+
+	if (KVM_GUEST_KSEGX(badvaddr) < KVM_GUEST_KSEG0
+	    || KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG23) {
+		/*
+		 * First find the mapping in the guest TLB. If the failure to
+		 * write was due to the guest TLB, it should be up to the guest
+		 * to handle it.
+		 */
+		entryhi = (badvaddr & VPN2_MASK) |
+			  (kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID);
+		index = kvm_mips_guest_tlb_lookup(vcpu, entryhi);
+
+		/*
+		 * These should never happen.
+		 * They would indicate stale host TLB entries.
+		 */
+		if (unlikely(index < 0)) {
+			vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+			return RESUME_HOST;
+		}
+		tlb = vcpu->arch.guest_tlb + index;
+		if (unlikely(!TLB_IS_VALID(*tlb, badvaddr))) {
+			vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+			return RESUME_HOST;
+		}
+
+		/*
+		 * Guest entry not dirty? That would explain the TLB modified
+		 * exception. Relay that on to the guest so it can handle it.
+		 */
+		if (!TLB_IS_DIRTY(*tlb, badvaddr)) {
+			kvm_mips_emulate_tlbmod(cause, opc, vcpu);
+			return RESUME_GUEST;
+		}
+
+		if (kvm_mips_handle_mapped_seg_tlb_fault(vcpu, tlb, badvaddr,
+							 true))
+			/* Not writable, needs handling as MMIO */
+			return kvm_mips_bad_store(cause, opc, vcpu);
+		return RESUME_GUEST;
+	} else if (KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG0) {
+		if (kvm_mips_handle_kseg0_tlb_fault(badvaddr, vcpu, true) < 0)
+			/* Not writable, needs handling as MMIO */
+			return kvm_mips_bad_store(cause, opc, vcpu);
+		return RESUME_GUEST;
+	} else {
+		/* host kernel addresses are all handled as MMIO */
+		return kvm_mips_bad_store(cause, opc, vcpu);
+	}
+}
+
+static int kvm_trap_emul_handle_tlb_miss(struct kvm_vcpu *vcpu, bool store)
+{
+	struct kvm_run *run = vcpu->run;
+	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
+	unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
+	u32 cause = vcpu->arch.host_cp0_cause;
+	enum emulation_result er = EMULATE_DONE;
+	int ret = RESUME_GUEST;
+
+	if (((badvaddr & PAGE_MASK) == KVM_GUEST_COMMPAGE_ADDR)
+	    && KVM_GUEST_KERNEL_MODE(vcpu)) {
+		if (kvm_mips_handle_commpage_tlb_fault(badvaddr, vcpu) < 0) {
+			run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+			ret = RESUME_HOST;
+		}
+	} else if (KVM_GUEST_KSEGX(badvaddr) < KVM_GUEST_KSEG0
+		   || KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG23) {
+		kvm_debug("USER ADDR TLB %s fault: cause %#x, PC: %p, BadVaddr: %#lx\n",
+			  store ? "ST" : "LD", cause, opc, badvaddr);
+
+		/*
+		 * User Address (UA) fault, this could happen if
+		 * (1) TLB entry not present/valid in both Guest and shadow host
+		 *     TLBs, in this case we pass on the fault to the guest
+		 *     kernel and let it handle it.
+		 * (2) TLB entry is present in the Guest TLB but not in the
+		 *     shadow, in this case we inject the TLB from the Guest TLB
+		 *     into the shadow host TLB
+		 */
+
+		er = kvm_mips_handle_tlbmiss(cause, opc, vcpu, store);
+		if (er == EMULATE_DONE)
+			ret = RESUME_GUEST;
+		else {
+			run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+			ret = RESUME_HOST;
+		}
+	} else if (KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG0) {
+		/*
+		 * All KSEG0 faults are handled by KVM, as the guest kernel does
+		 * not expect to ever get them
+		 */
+		if (kvm_mips_handle_kseg0_tlb_fault(badvaddr, vcpu, store) < 0)
+			ret = kvm_mips_bad_access(cause, opc, vcpu, store);
+	} else if (KVM_GUEST_KERNEL_MODE(vcpu)
+		   && (KSEGX(badvaddr) == CKSEG0 || KSEGX(badvaddr) == CKSEG1)) {
+		/*
+		 * With EVA we may get a TLB exception instead of an address
+		 * error when the guest performs MMIO to KSeg1 addresses.
+		 */
+		ret = kvm_mips_bad_access(cause, opc, vcpu, store);
+	} else {
+		kvm_err("Illegal TLB %s fault address , cause %#x, PC: %p, BadVaddr: %#lx\n",
+			store ? "ST" : "LD", cause, opc, badvaddr);
+		kvm_mips_dump_host_tlbs();
+		kvm_arch_vcpu_dump_regs(vcpu);
+		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+		ret = RESUME_HOST;
+	}
+	return ret;
+}
+
+static int kvm_trap_emul_handle_tlb_st_miss(struct kvm_vcpu *vcpu)
+{
+	return kvm_trap_emul_handle_tlb_miss(vcpu, true);
+}
+
+static int kvm_trap_emul_handle_tlb_ld_miss(struct kvm_vcpu *vcpu)
+{
+	return kvm_trap_emul_handle_tlb_miss(vcpu, false);
+}
+
+static int kvm_trap_emul_handle_addr_err_st(struct kvm_vcpu *vcpu)
+{
+	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
+	unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
+	u32 cause = vcpu->arch.host_cp0_cause;
+	int ret = RESUME_GUEST;
+
+	if (KVM_GUEST_KERNEL_MODE(vcpu)
+	    && (KSEGX(badvaddr) == CKSEG0 || KSEGX(badvaddr) == CKSEG1)) {
+		ret = kvm_mips_bad_store(cause, opc, vcpu);
+	} else {
+		kvm_err("Address Error (STORE): cause %#x, PC: %p, BadVaddr: %#lx\n",
+			cause, opc, badvaddr);
+		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+		ret = RESUME_HOST;
+	}
+	return ret;
+}
+
+static int kvm_trap_emul_handle_addr_err_ld(struct kvm_vcpu *vcpu)
+{
+	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
+	unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
+	u32 cause = vcpu->arch.host_cp0_cause;
+	int ret = RESUME_GUEST;
+
+	if (KSEGX(badvaddr) == CKSEG0 || KSEGX(badvaddr) == CKSEG1) {
+		ret = kvm_mips_bad_load(cause, opc, vcpu);
+	} else {
+		kvm_err("Address Error (LOAD): cause %#x, PC: %p, BadVaddr: %#lx\n",
+			cause, opc, badvaddr);
+		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+		ret = RESUME_HOST;
+	}
+	return ret;
+}
+
+static int kvm_trap_emul_handle_syscall(struct kvm_vcpu *vcpu)
+{
+	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
+	u32 cause = vcpu->arch.host_cp0_cause;
+	enum emulation_result er = EMULATE_DONE;
+	int ret = RESUME_GUEST;
+
+	er = kvm_mips_emulate_syscall(cause, opc, vcpu);
+	if (er == EMULATE_DONE)
+		ret = RESUME_GUEST;
+	else {
+		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+		ret = RESUME_HOST;
+	}
+	return ret;
+}
+
+static int kvm_trap_emul_handle_res_inst(struct kvm_vcpu *vcpu)
+{
+	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
+	u32 cause = vcpu->arch.host_cp0_cause;
+	enum emulation_result er = EMULATE_DONE;
+	int ret = RESUME_GUEST;
+
+	er = kvm_mips_handle_ri(cause, opc, vcpu);
+	if (er == EMULATE_DONE)
+		ret = RESUME_GUEST;
+	else {
+		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+		ret = RESUME_HOST;
+	}
+	return ret;
+}
+
+static int kvm_trap_emul_handle_break(struct kvm_vcpu *vcpu)
+{
+	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
+	u32 cause = vcpu->arch.host_cp0_cause;
+	enum emulation_result er = EMULATE_DONE;
+	int ret = RESUME_GUEST;
+
+	er = kvm_mips_emulate_bp_exc(cause, opc, vcpu);
+	if (er == EMULATE_DONE)
+		ret = RESUME_GUEST;
+	else {
+		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+		ret = RESUME_HOST;
+	}
+	return ret;
+}
+
+static int kvm_trap_emul_handle_trap(struct kvm_vcpu *vcpu)
+{
+	u32 __user *opc = (u32 __user *)vcpu->arch.pc;
+	u32 cause = vcpu->arch.host_cp0_cause;
+	enum emulation_result er = EMULATE_DONE;
+	int ret = RESUME_GUEST;
+
+	er = kvm_mips_emulate_trap_exc(cause, opc, vcpu);
+	if (er == EMULATE_DONE) {
+		ret = RESUME_GUEST;
+	} else {
+		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+		ret = RESUME_HOST;
+	}
+	return ret;
+}
+
+static int kvm_trap_emul_handle_msa_fpe(struct kvm_vcpu *vcpu)
+{
+	u32 __user *opc = (u32 __user *)vcpu->arch.pc;
+	u32 cause = vcpu->arch.host_cp0_cause;
+	enum emulation_result er = EMULATE_DONE;
+	int ret = RESUME_GUEST;
+
+	er = kvm_mips_emulate_msafpe_exc(cause, opc, vcpu);
+	if (er == EMULATE_DONE) {
+		ret = RESUME_GUEST;
+	} else {
+		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+		ret = RESUME_HOST;
+	}
+	return ret;
+}
+
+static int kvm_trap_emul_handle_fpe(struct kvm_vcpu *vcpu)
+{
+	u32 __user *opc = (u32 __user *)vcpu->arch.pc;
+	u32 cause = vcpu->arch.host_cp0_cause;
+	enum emulation_result er = EMULATE_DONE;
+	int ret = RESUME_GUEST;
+
+	er = kvm_mips_emulate_fpe_exc(cause, opc, vcpu);
+	if (er == EMULATE_DONE) {
+		ret = RESUME_GUEST;
+	} else {
+		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+		ret = RESUME_HOST;
+	}
+	return ret;
+}
+
+/**
+ * kvm_trap_emul_handle_msa_disabled() - Guest used MSA while disabled in root.
+ * @vcpu:	Virtual CPU context.
+ *
+ * Handle when the guest attempts to use MSA when it is disabled.
+ */
+static int kvm_trap_emul_handle_msa_disabled(struct kvm_vcpu *vcpu)
+{
+	struct mips_coproc *cop0 = vcpu->arch.cop0;
+	u32 __user *opc = (u32 __user *) vcpu->arch.pc;
+	u32 cause = vcpu->arch.host_cp0_cause;
+	enum emulation_result er = EMULATE_DONE;
+	int ret = RESUME_GUEST;
+
+	if (!kvm_mips_guest_has_msa(&vcpu->arch) ||
+	    (kvm_read_c0_guest_status(cop0) & (ST0_CU1 | ST0_FR)) == ST0_CU1) {
+		/*
+		 * No MSA in guest, or FPU enabled and not in FR=1 mode,
+		 * guest reserved instruction exception
+		 */
+		er = kvm_mips_emulate_ri_exc(cause, opc, vcpu);
+	} else if (!(kvm_read_c0_guest_config5(cop0) & MIPS_CONF5_MSAEN)) {
+		/* MSA disabled by guest, guest MSA disabled exception */
+		er = kvm_mips_emulate_msadis_exc(cause, opc, vcpu);
+	} else {
+		/* Restore MSA/FPU state */
+		kvm_own_msa(vcpu);
+		er = EMULATE_DONE;
+	}
+
+	switch (er) {
+	case EMULATE_DONE:
+		ret = RESUME_GUEST;
+		break;
+
+	case EMULATE_FAIL:
+		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+		ret = RESUME_HOST;
+		break;
+
+	default:
+		BUG();
+	}
+	return ret;
+}
+
+static int kvm_trap_emul_hardware_enable(void)
+{
+	return 0;
+}
+
+static void kvm_trap_emul_hardware_disable(void)
+{
+}
+
+static int kvm_trap_emul_check_extension(struct kvm *kvm, long ext)
+{
+	int r;
+
+	switch (ext) {
+	case KVM_CAP_MIPS_TE:
+		r = 1;
+		break;
+	case KVM_CAP_IOEVENTFD:
+		r = 1;
+		break;
+	default:
+		r = 0;
+		break;
+	}
+
+	return r;
+}
+
+static int kvm_trap_emul_vcpu_init(struct kvm_vcpu *vcpu)
+{
+	struct mm_struct *kern_mm = &vcpu->arch.guest_kernel_mm;
+	struct mm_struct *user_mm = &vcpu->arch.guest_user_mm;
+
+	/*
+	 * Allocate GVA -> HPA page tables.
+	 * MIPS doesn't use the mm_struct pointer argument.
+	 */
+	kern_mm->pgd = pgd_alloc(kern_mm);
+	if (!kern_mm->pgd)
+		return -ENOMEM;
+
+	user_mm->pgd = pgd_alloc(user_mm);
+	if (!user_mm->pgd) {
+		pgd_free(kern_mm, kern_mm->pgd);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static void kvm_mips_emul_free_gva_pt(pgd_t *pgd)
+{
+	/* Don't free host kernel page tables copied from init_mm.pgd */
+	const unsigned long end = 0x80000000;
+	unsigned long pgd_va, pud_va, pmd_va;
+	p4d_t *p4d;
+	pud_t *pud;
+	pmd_t *pmd;
+	pte_t *pte;
+	int i, j, k;
+
+	for (i = 0; i < USER_PTRS_PER_PGD; i++) {
+		if (pgd_none(pgd[i]))
+			continue;
+
+		pgd_va = (unsigned long)i << PGDIR_SHIFT;
+		if (pgd_va >= end)
+			break;
+		p4d = p4d_offset(pgd, 0);
+		pud = pud_offset(p4d + i, 0);
+		for (j = 0; j < PTRS_PER_PUD; j++) {
+			if (pud_none(pud[j]))
+				continue;
+
+			pud_va = pgd_va | ((unsigned long)j << PUD_SHIFT);
+			if (pud_va >= end)
+				break;
+			pmd = pmd_offset(pud + j, 0);
+			for (k = 0; k < PTRS_PER_PMD; k++) {
+				if (pmd_none(pmd[k]))
+					continue;
+
+				pmd_va = pud_va | (k << PMD_SHIFT);
+				if (pmd_va >= end)
+					break;
+				pte = pte_offset_kernel(pmd + k, 0);
+				pte_free_kernel(NULL, pte);
+			}
+			pmd_free(NULL, pmd);
+		}
+		pud_free(NULL, pud);
+	}
+	pgd_free(NULL, pgd);
+}
+
+static void kvm_trap_emul_vcpu_uninit(struct kvm_vcpu *vcpu)
+{
+	kvm_mips_emul_free_gva_pt(vcpu->arch.guest_kernel_mm.pgd);
+	kvm_mips_emul_free_gva_pt(vcpu->arch.guest_user_mm.pgd);
+}
+
+static int kvm_trap_emul_vcpu_setup(struct kvm_vcpu *vcpu)
+{
+	struct mips_coproc *cop0 = vcpu->arch.cop0;
+	u32 config, config1;
+	int vcpu_id = vcpu->vcpu_id;
+
+	/* Start off the timer at 100 MHz */
+	kvm_mips_init_count(vcpu, 100*1000*1000);
+
+	/*
+	 * Arch specific stuff, set up config registers properly so that the
+	 * guest will come up as expected
+	 */
+#ifndef CONFIG_CPU_MIPSR6
+	/* r2-r5, simulate a MIPS 24kc */
+	kvm_write_c0_guest_prid(cop0, 0x00019300);
+#else
+	/* r6+, simulate a generic QEMU machine */
+	kvm_write_c0_guest_prid(cop0, 0x00010000);
+#endif
+	/*
+	 * Have config1, Cacheable, noncoherent, write-back, write allocate.
+	 * Endianness, arch revision & virtually tagged icache should match
+	 * host.
+	 */
+	config = read_c0_config() & MIPS_CONF_AR;
+	config |= MIPS_CONF_M | CONF_CM_CACHABLE_NONCOHERENT | MIPS_CONF_MT_TLB;
+#ifdef CONFIG_CPU_BIG_ENDIAN
+	config |= CONF_BE;
+#endif
+	if (cpu_has_vtag_icache)
+		config |= MIPS_CONF_VI;
+	kvm_write_c0_guest_config(cop0, config);
+
+	/* Read the cache characteristics from the host Config1 Register */
+	config1 = (read_c0_config1() & ~0x7f);
+
+	/* DCache line size not correctly reported in Config1 on Octeon CPUs */
+	if (cpu_dcache_line_size()) {
+		config1 &= ~MIPS_CONF1_DL;
+		config1 |= ((ilog2(cpu_dcache_line_size()) - 1) <<
+			    MIPS_CONF1_DL_SHF) & MIPS_CONF1_DL;
+	}
+
+	/* Set up MMU size */
+	config1 &= ~(0x3f << 25);
+	config1 |= ((KVM_MIPS_GUEST_TLB_SIZE - 1) << 25);
+
+	/* We unset some bits that we aren't emulating */
+	config1 &= ~(MIPS_CONF1_C2 | MIPS_CONF1_MD | MIPS_CONF1_PC |
+		     MIPS_CONF1_WR | MIPS_CONF1_CA);
+	kvm_write_c0_guest_config1(cop0, config1);
+
+	/* Have config3, no tertiary/secondary caches implemented */
+	kvm_write_c0_guest_config2(cop0, MIPS_CONF_M);
+	/* MIPS_CONF_M | (read_c0_config2() & 0xfff) */
+
+	/* Have config4, UserLocal */
+	kvm_write_c0_guest_config3(cop0, MIPS_CONF_M | MIPS_CONF3_ULRI);
+
+	/* Have config5 */
+	kvm_write_c0_guest_config4(cop0, MIPS_CONF_M);
+
+	/* No config6 */
+	kvm_write_c0_guest_config5(cop0, 0);
+
+	/* Set Wait IE/IXMT Ignore in Config7, IAR, AR */
+	kvm_write_c0_guest_config7(cop0, (MIPS_CONF7_WII) | (1 << 10));
+
+	/* Status */
+	kvm_write_c0_guest_status(cop0, ST0_BEV | ST0_ERL);
+
+	/*
+	 * Setup IntCtl defaults, compatibility mode for timer interrupts (HW5)
+	 */
+	kvm_write_c0_guest_intctl(cop0, 0xFC000000);
+
+	/* Put in vcpu id as CPUNum into Ebase Reg to handle SMP Guests */
+	kvm_write_c0_guest_ebase(cop0, KVM_GUEST_KSEG0 |
+				       (vcpu_id & MIPS_EBASE_CPUNUM));
+
+	/* Put PC at guest reset vector */
+	vcpu->arch.pc = KVM_GUEST_CKSEG1ADDR(0x1fc00000);
+
+	return 0;
+}
+
+static void kvm_trap_emul_flush_shadow_all(struct kvm *kvm)
+{
+	/* Flush GVA page tables and invalidate GVA ASIDs on all VCPUs */
+	kvm_flush_remote_tlbs(kvm);
+}
+
+static void kvm_trap_emul_flush_shadow_memslot(struct kvm *kvm,
+					const struct kvm_memory_slot *slot)
+{
+	kvm_trap_emul_flush_shadow_all(kvm);
+}
+
+static u64 kvm_trap_emul_get_one_regs[] = {
+	KVM_REG_MIPS_CP0_INDEX,
+	KVM_REG_MIPS_CP0_ENTRYLO0,
+	KVM_REG_MIPS_CP0_ENTRYLO1,
+	KVM_REG_MIPS_CP0_CONTEXT,
+	KVM_REG_MIPS_CP0_USERLOCAL,
+	KVM_REG_MIPS_CP0_PAGEMASK,
+	KVM_REG_MIPS_CP0_WIRED,
+	KVM_REG_MIPS_CP0_HWRENA,
+	KVM_REG_MIPS_CP0_BADVADDR,
+	KVM_REG_MIPS_CP0_COUNT,
+	KVM_REG_MIPS_CP0_ENTRYHI,
+	KVM_REG_MIPS_CP0_COMPARE,
+	KVM_REG_MIPS_CP0_STATUS,
+	KVM_REG_MIPS_CP0_INTCTL,
+	KVM_REG_MIPS_CP0_CAUSE,
+	KVM_REG_MIPS_CP0_EPC,
+	KVM_REG_MIPS_CP0_PRID,
+	KVM_REG_MIPS_CP0_EBASE,
+	KVM_REG_MIPS_CP0_CONFIG,
+	KVM_REG_MIPS_CP0_CONFIG1,
+	KVM_REG_MIPS_CP0_CONFIG2,
+	KVM_REG_MIPS_CP0_CONFIG3,
+	KVM_REG_MIPS_CP0_CONFIG4,
+	KVM_REG_MIPS_CP0_CONFIG5,
+	KVM_REG_MIPS_CP0_CONFIG7,
+	KVM_REG_MIPS_CP0_ERROREPC,
+	KVM_REG_MIPS_CP0_KSCRATCH1,
+	KVM_REG_MIPS_CP0_KSCRATCH2,
+	KVM_REG_MIPS_CP0_KSCRATCH3,
+	KVM_REG_MIPS_CP0_KSCRATCH4,
+	KVM_REG_MIPS_CP0_KSCRATCH5,
+	KVM_REG_MIPS_CP0_KSCRATCH6,
+
+	KVM_REG_MIPS_COUNT_CTL,
+	KVM_REG_MIPS_COUNT_RESUME,
+	KVM_REG_MIPS_COUNT_HZ,
+};
+
+static unsigned long kvm_trap_emul_num_regs(struct kvm_vcpu *vcpu)
+{
+	return ARRAY_SIZE(kvm_trap_emul_get_one_regs);
+}
+
+static int kvm_trap_emul_copy_reg_indices(struct kvm_vcpu *vcpu,
+					  u64 __user *indices)
+{
+	if (copy_to_user(indices, kvm_trap_emul_get_one_regs,
+			 sizeof(kvm_trap_emul_get_one_regs)))
+		return -EFAULT;
+	indices += ARRAY_SIZE(kvm_trap_emul_get_one_regs);
+
+	return 0;
+}
+
+static int kvm_trap_emul_get_one_reg(struct kvm_vcpu *vcpu,
+				     const struct kvm_one_reg *reg,
+				     s64 *v)
+{
+	struct mips_coproc *cop0 = vcpu->arch.cop0;
+
+	switch (reg->id) {
+	case KVM_REG_MIPS_CP0_INDEX:
+		*v = (long)kvm_read_c0_guest_index(cop0);
+		break;
+	case KVM_REG_MIPS_CP0_ENTRYLO0:
+		*v = kvm_read_c0_guest_entrylo0(cop0);
+		break;
+	case KVM_REG_MIPS_CP0_ENTRYLO1:
+		*v = kvm_read_c0_guest_entrylo1(cop0);
+		break;
+	case KVM_REG_MIPS_CP0_CONTEXT:
+		*v = (long)kvm_read_c0_guest_context(cop0);
+		break;
+	case KVM_REG_MIPS_CP0_USERLOCAL:
+		*v = (long)kvm_read_c0_guest_userlocal(cop0);
+		break;
+	case KVM_REG_MIPS_CP0_PAGEMASK:
+		*v = (long)kvm_read_c0_guest_pagemask(cop0);
+		break;
+	case KVM_REG_MIPS_CP0_WIRED:
+		*v = (long)kvm_read_c0_guest_wired(cop0);
+		break;
+	case KVM_REG_MIPS_CP0_HWRENA:
+		*v = (long)kvm_read_c0_guest_hwrena(cop0);
+		break;
+	case KVM_REG_MIPS_CP0_BADVADDR:
+		*v = (long)kvm_read_c0_guest_badvaddr(cop0);
+		break;
+	case KVM_REG_MIPS_CP0_ENTRYHI:
+		*v = (long)kvm_read_c0_guest_entryhi(cop0);
+		break;
+	case KVM_REG_MIPS_CP0_COMPARE:
+		*v = (long)kvm_read_c0_guest_compare(cop0);
+		break;
+	case KVM_REG_MIPS_CP0_STATUS:
+		*v = (long)kvm_read_c0_guest_status(cop0);
+		break;
+	case KVM_REG_MIPS_CP0_INTCTL:
+		*v = (long)kvm_read_c0_guest_intctl(cop0);
+		break;
+	case KVM_REG_MIPS_CP0_CAUSE:
+		*v = (long)kvm_read_c0_guest_cause(cop0);
+		break;
+	case KVM_REG_MIPS_CP0_EPC:
+		*v = (long)kvm_read_c0_guest_epc(cop0);
+		break;
+	case KVM_REG_MIPS_CP0_PRID:
+		*v = (long)kvm_read_c0_guest_prid(cop0);
+		break;
+	case KVM_REG_MIPS_CP0_EBASE:
+		*v = (long)kvm_read_c0_guest_ebase(cop0);
+		break;
+	case KVM_REG_MIPS_CP0_CONFIG:
+		*v = (long)kvm_read_c0_guest_config(cop0);
+		break;
+	case KVM_REG_MIPS_CP0_CONFIG1:
+		*v = (long)kvm_read_c0_guest_config1(cop0);
+		break;
+	case KVM_REG_MIPS_CP0_CONFIG2:
+		*v = (long)kvm_read_c0_guest_config2(cop0);
+		break;
+	case KVM_REG_MIPS_CP0_CONFIG3:
+		*v = (long)kvm_read_c0_guest_config3(cop0);
+		break;
+	case KVM_REG_MIPS_CP0_CONFIG4:
+		*v = (long)kvm_read_c0_guest_config4(cop0);
+		break;
+	case KVM_REG_MIPS_CP0_CONFIG5:
+		*v = (long)kvm_read_c0_guest_config5(cop0);
+		break;
+	case KVM_REG_MIPS_CP0_CONFIG7:
+		*v = (long)kvm_read_c0_guest_config7(cop0);
+		break;
+	case KVM_REG_MIPS_CP0_COUNT:
+		*v = kvm_mips_read_count(vcpu);
+		break;
+	case KVM_REG_MIPS_COUNT_CTL:
+		*v = vcpu->arch.count_ctl;
+		break;
+	case KVM_REG_MIPS_COUNT_RESUME:
+		*v = ktime_to_ns(vcpu->arch.count_resume);
+		break;
+	case KVM_REG_MIPS_COUNT_HZ:
+		*v = vcpu->arch.count_hz;
+		break;
+	case KVM_REG_MIPS_CP0_ERROREPC:
+		*v = (long)kvm_read_c0_guest_errorepc(cop0);
+		break;
+	case KVM_REG_MIPS_CP0_KSCRATCH1:
+		*v = (long)kvm_read_c0_guest_kscratch1(cop0);
+		break;
+	case KVM_REG_MIPS_CP0_KSCRATCH2:
+		*v = (long)kvm_read_c0_guest_kscratch2(cop0);
+		break;
+	case KVM_REG_MIPS_CP0_KSCRATCH3:
+		*v = (long)kvm_read_c0_guest_kscratch3(cop0);
+		break;
+	case KVM_REG_MIPS_CP0_KSCRATCH4:
+		*v = (long)kvm_read_c0_guest_kscratch4(cop0);
+		break;
+	case KVM_REG_MIPS_CP0_KSCRATCH5:
+		*v = (long)kvm_read_c0_guest_kscratch5(cop0);
+		break;
+	case KVM_REG_MIPS_CP0_KSCRATCH6:
+		*v = (long)kvm_read_c0_guest_kscratch6(cop0);
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int kvm_trap_emul_set_one_reg(struct kvm_vcpu *vcpu,
+				     const struct kvm_one_reg *reg,
+				     s64 v)
+{
+	struct mips_coproc *cop0 = vcpu->arch.cop0;
+	int ret = 0;
+	unsigned int cur, change;
+
+	switch (reg->id) {
+	case KVM_REG_MIPS_CP0_INDEX:
+		kvm_write_c0_guest_index(cop0, v);
+		break;
+	case KVM_REG_MIPS_CP0_ENTRYLO0:
+		kvm_write_c0_guest_entrylo0(cop0, v);
+		break;
+	case KVM_REG_MIPS_CP0_ENTRYLO1:
+		kvm_write_c0_guest_entrylo1(cop0, v);
+		break;
+	case KVM_REG_MIPS_CP0_CONTEXT:
+		kvm_write_c0_guest_context(cop0, v);
+		break;
+	case KVM_REG_MIPS_CP0_USERLOCAL:
+		kvm_write_c0_guest_userlocal(cop0, v);
+		break;
+	case KVM_REG_MIPS_CP0_PAGEMASK:
+		kvm_write_c0_guest_pagemask(cop0, v);
+		break;
+	case KVM_REG_MIPS_CP0_WIRED:
+		kvm_write_c0_guest_wired(cop0, v);
+		break;
+	case KVM_REG_MIPS_CP0_HWRENA:
+		kvm_write_c0_guest_hwrena(cop0, v);
+		break;
+	case KVM_REG_MIPS_CP0_BADVADDR:
+		kvm_write_c0_guest_badvaddr(cop0, v);
+		break;
+	case KVM_REG_MIPS_CP0_ENTRYHI:
+		kvm_write_c0_guest_entryhi(cop0, v);
+		break;
+	case KVM_REG_MIPS_CP0_STATUS:
+		kvm_write_c0_guest_status(cop0, v);
+		break;
+	case KVM_REG_MIPS_CP0_INTCTL:
+		/* No VInt, so no VS, read-only for now */
+		break;
+	case KVM_REG_MIPS_CP0_EPC:
+		kvm_write_c0_guest_epc(cop0, v);
+		break;
+	case KVM_REG_MIPS_CP0_PRID:
+		kvm_write_c0_guest_prid(cop0, v);
+		break;
+	case KVM_REG_MIPS_CP0_EBASE:
+		/*
+		 * Allow core number to be written, but the exception base must
+		 * remain in guest KSeg0.
+		 */
+		kvm_change_c0_guest_ebase(cop0, 0x1ffff000 | MIPS_EBASE_CPUNUM,
+					  v);
+		break;
+	case KVM_REG_MIPS_CP0_COUNT:
+		kvm_mips_write_count(vcpu, v);
+		break;
+	case KVM_REG_MIPS_CP0_COMPARE:
+		kvm_mips_write_compare(vcpu, v, false);
+		break;
+	case KVM_REG_MIPS_CP0_CAUSE:
+		/*
+		 * If the timer is stopped or started (DC bit) it must look
+		 * atomic with changes to the interrupt pending bits (TI, IRQ5).
+		 * A timer interrupt should not happen in between.
+		 */
+		if ((kvm_read_c0_guest_cause(cop0) ^ v) & CAUSEF_DC) {
+			if (v & CAUSEF_DC) {
+				/* disable timer first */
+				kvm_mips_count_disable_cause(vcpu);
+				kvm_change_c0_guest_cause(cop0, (u32)~CAUSEF_DC,
+							  v);
+			} else {
+				/* enable timer last */
+				kvm_change_c0_guest_cause(cop0, (u32)~CAUSEF_DC,
+							  v);
+				kvm_mips_count_enable_cause(vcpu);
+			}
+		} else {
+			kvm_write_c0_guest_cause(cop0, v);
+		}
+		break;
+	case KVM_REG_MIPS_CP0_CONFIG:
+		/* read-only for now */
+		break;
+	case KVM_REG_MIPS_CP0_CONFIG1:
+		cur = kvm_read_c0_guest_config1(cop0);
+		change = (cur ^ v) & kvm_mips_config1_wrmask(vcpu);
+		if (change) {
+			v = cur ^ change;
+			kvm_write_c0_guest_config1(cop0, v);
+		}
+		break;
+	case KVM_REG_MIPS_CP0_CONFIG2:
+		/* read-only for now */
+		break;
+	case KVM_REG_MIPS_CP0_CONFIG3:
+		cur = kvm_read_c0_guest_config3(cop0);
+		change = (cur ^ v) & kvm_mips_config3_wrmask(vcpu);
+		if (change) {
+			v = cur ^ change;
+			kvm_write_c0_guest_config3(cop0, v);
+		}
+		break;
+	case KVM_REG_MIPS_CP0_CONFIG4:
+		cur = kvm_read_c0_guest_config4(cop0);
+		change = (cur ^ v) & kvm_mips_config4_wrmask(vcpu);
+		if (change) {
+			v = cur ^ change;
+			kvm_write_c0_guest_config4(cop0, v);
+		}
+		break;
+	case KVM_REG_MIPS_CP0_CONFIG5:
+		cur = kvm_read_c0_guest_config5(cop0);
+		change = (cur ^ v) & kvm_mips_config5_wrmask(vcpu);
+		if (change) {
+			v = cur ^ change;
+			kvm_write_c0_guest_config5(cop0, v);
+		}
+		break;
+	case KVM_REG_MIPS_CP0_CONFIG7:
+		/* writes ignored */
+		break;
+	case KVM_REG_MIPS_COUNT_CTL:
+		ret = kvm_mips_set_count_ctl(vcpu, v);
+		break;
+	case KVM_REG_MIPS_COUNT_RESUME:
+		ret = kvm_mips_set_count_resume(vcpu, v);
+		break;
+	case KVM_REG_MIPS_COUNT_HZ:
+		ret = kvm_mips_set_count_hz(vcpu, v);
+		break;
+	case KVM_REG_MIPS_CP0_ERROREPC:
+		kvm_write_c0_guest_errorepc(cop0, v);
+		break;
+	case KVM_REG_MIPS_CP0_KSCRATCH1:
+		kvm_write_c0_guest_kscratch1(cop0, v);
+		break;
+	case KVM_REG_MIPS_CP0_KSCRATCH2:
+		kvm_write_c0_guest_kscratch2(cop0, v);
+		break;
+	case KVM_REG_MIPS_CP0_KSCRATCH3:
+		kvm_write_c0_guest_kscratch3(cop0, v);
+		break;
+	case KVM_REG_MIPS_CP0_KSCRATCH4:
+		kvm_write_c0_guest_kscratch4(cop0, v);
+		break;
+	case KVM_REG_MIPS_CP0_KSCRATCH5:
+		kvm_write_c0_guest_kscratch5(cop0, v);
+		break;
+	case KVM_REG_MIPS_CP0_KSCRATCH6:
+		kvm_write_c0_guest_kscratch6(cop0, v);
+		break;
+	default:
+		return -EINVAL;
+	}
+	return ret;
+}
+
+static int kvm_trap_emul_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
+{
+	struct mm_struct *kern_mm = &vcpu->arch.guest_kernel_mm;
+	struct mm_struct *user_mm = &vcpu->arch.guest_user_mm;
+	struct mm_struct *mm;
+
+	/*
+	 * Were we in guest context? If so, restore the appropriate ASID based
+	 * on the mode of the Guest (Kernel/User).
+	 */
+	if (current->flags & PF_VCPU) {
+		mm = KVM_GUEST_KERNEL_MODE(vcpu) ? kern_mm : user_mm;
+		check_switch_mmu_context(mm);
+		kvm_mips_suspend_mm(cpu);
+		ehb();
+	}
+
+	return 0;
+}
+
+static int kvm_trap_emul_vcpu_put(struct kvm_vcpu *vcpu, int cpu)
+{
+	kvm_lose_fpu(vcpu);
+
+	if (current->flags & PF_VCPU) {
+		/* Restore normal Linux process memory map */
+		check_switch_mmu_context(current->mm);
+		kvm_mips_resume_mm(cpu);
+		ehb();
+	}
+
+	return 0;
+}
+
+static void kvm_trap_emul_check_requests(struct kvm_vcpu *vcpu, int cpu,
+					 bool reload_asid)
+{
+	struct mm_struct *kern_mm = &vcpu->arch.guest_kernel_mm;
+	struct mm_struct *user_mm = &vcpu->arch.guest_user_mm;
+	struct mm_struct *mm;
+	int i;
+
+	if (likely(!kvm_request_pending(vcpu)))
+		return;
+
+	if (kvm_check_request(KVM_REQ_TLB_FLUSH, vcpu)) {
+		/*
+		 * Both kernel & user GVA mappings must be invalidated. The
+		 * caller is just about to check whether the ASID is stale
+		 * anyway so no need to reload it here.
+		 */
+		kvm_mips_flush_gva_pt(kern_mm->pgd, KMF_GPA | KMF_KERN);
+		kvm_mips_flush_gva_pt(user_mm->pgd, KMF_GPA | KMF_USER);
+		for_each_possible_cpu(i) {
+			set_cpu_context(i, kern_mm, 0);
+			set_cpu_context(i, user_mm, 0);
+		}
+
+		/* Generate new ASID for current mode */
+		if (reload_asid) {
+			mm = KVM_GUEST_KERNEL_MODE(vcpu) ? kern_mm : user_mm;
+			get_new_mmu_context(mm);
+			htw_stop();
+			write_c0_entryhi(cpu_asid(cpu, mm));
+			TLBMISS_HANDLER_SETUP_PGD(mm->pgd);
+			htw_start();
+		}
+	}
+}
+
+/**
+ * kvm_trap_emul_gva_lockless_begin() - Begin lockless access to GVA space.
+ * @vcpu:	VCPU pointer.
+ *
+ * Call before a GVA space access outside of guest mode, to ensure that
+ * asynchronous TLB flush requests are handled or delayed until completion of
+ * the GVA access (as indicated by a matching kvm_trap_emul_gva_lockless_end()).
+ *
+ * Should be called with IRQs already enabled.
+ */
+void kvm_trap_emul_gva_lockless_begin(struct kvm_vcpu *vcpu)
+{
+	/* We re-enable IRQs in kvm_trap_emul_gva_lockless_end() */
+	WARN_ON_ONCE(irqs_disabled());
+
+	/*
+	 * The caller is about to access the GVA space, so we set the mode to
+	 * force TLB flush requests to send an IPI, and also disable IRQs to
+	 * delay IPI handling until kvm_trap_emul_gva_lockless_end().
+	 */
+	local_irq_disable();
+
+	/*
+	 * Make sure the read of VCPU requests is not reordered ahead of the
+	 * write to vcpu->mode, or we could miss a TLB flush request while
+	 * the requester sees the VCPU as outside of guest mode and not needing
+	 * an IPI.
+	 */
+	smp_store_mb(vcpu->mode, READING_SHADOW_PAGE_TABLES);
+
+	/*
+	 * If a TLB flush has been requested (potentially while
+	 * OUTSIDE_GUEST_MODE and assumed immediately effective), perform it
+	 * before accessing the GVA space, and be sure to reload the ASID if
+	 * necessary as it'll be immediately used.
+	 *
+	 * TLB flush requests after this check will trigger an IPI due to the
+	 * mode change above, which will be delayed due to IRQs disabled.
+	 */
+	kvm_trap_emul_check_requests(vcpu, smp_processor_id(), true);
+}
+
+/**
+ * kvm_trap_emul_gva_lockless_end() - End lockless access to GVA space.
+ * @vcpu:	VCPU pointer.
+ *
+ * Called after a GVA space access outside of guest mode. Should have a matching
+ * call to kvm_trap_emul_gva_lockless_begin().
+ */
+void kvm_trap_emul_gva_lockless_end(struct kvm_vcpu *vcpu)
+{
+	/*
+	 * Make sure the write to vcpu->mode is not reordered in front of GVA
+	 * accesses, or a TLB flush requester may not think it necessary to send
+	 * an IPI.
+	 */
+	smp_store_release(&vcpu->mode, OUTSIDE_GUEST_MODE);
+
+	/*
+	 * Now that the access to GVA space is complete, its safe for pending
+	 * TLB flush request IPIs to be handled (which indicates completion).
+	 */
+	local_irq_enable();
+}
+
+static void kvm_trap_emul_vcpu_reenter(struct kvm_vcpu *vcpu)
+{
+	struct mm_struct *kern_mm = &vcpu->arch.guest_kernel_mm;
+	struct mm_struct *user_mm = &vcpu->arch.guest_user_mm;
+	struct mm_struct *mm;
+	struct mips_coproc *cop0 = vcpu->arch.cop0;
+	int i, cpu = smp_processor_id();
+	unsigned int gasid;
+
+	/*
+	 * No need to reload ASID, IRQs are disabled already so there's no rush,
+	 * and we'll check if we need to regenerate below anyway before
+	 * re-entering the guest.
+	 */
+	kvm_trap_emul_check_requests(vcpu, cpu, false);
+
+	if (KVM_GUEST_KERNEL_MODE(vcpu)) {
+		mm = kern_mm;
+	} else {
+		mm = user_mm;
+
+		/*
+		 * Lazy host ASID regeneration / PT flush for guest user mode.
+		 * If the guest ASID has changed since the last guest usermode
+		 * execution, invalidate the stale TLB entries and flush GVA PT
+		 * entries too.
+		 */
+		gasid = kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID;
+		if (gasid != vcpu->arch.last_user_gasid) {
+			kvm_mips_flush_gva_pt(user_mm->pgd, KMF_USER);
+			for_each_possible_cpu(i)
+				set_cpu_context(i, user_mm, 0);
+			vcpu->arch.last_user_gasid = gasid;
+		}
+	}
+
+	/*
+	 * Check if ASID is stale. This may happen due to a TLB flush request or
+	 * a lazy user MM invalidation.
+	 */
+	check_mmu_context(mm);
+}
+
+static int kvm_trap_emul_vcpu_run(struct kvm_vcpu *vcpu)
+{
+	int cpu = smp_processor_id();
+	int r;
+
+	/* Check if we have any exceptions/interrupts pending */
+	kvm_mips_deliver_interrupts(vcpu,
+				    kvm_read_c0_guest_cause(vcpu->arch.cop0));
+
+	kvm_trap_emul_vcpu_reenter(vcpu);
+
+	/*
+	 * We use user accessors to access guest memory, but we don't want to
+	 * invoke Linux page faulting.
+	 */
+	pagefault_disable();
+
+	/* Disable hardware page table walking while in guest */
+	htw_stop();
+
+	/*
+	 * While in guest context we're in the guest's address space, not the
+	 * host process address space, so we need to be careful not to confuse
+	 * e.g. cache management IPIs.
+	 */
+	kvm_mips_suspend_mm(cpu);
+
+	r = vcpu->arch.vcpu_run(vcpu);
+
+	/* We may have migrated while handling guest exits */
+	cpu = smp_processor_id();
+
+	/* Restore normal Linux process memory map */
+	check_switch_mmu_context(current->mm);
+	kvm_mips_resume_mm(cpu);
+
+	htw_start();
+
+	pagefault_enable();
+
+	return r;
+}
+
+static struct kvm_mips_callbacks kvm_trap_emul_callbacks = {
+	/* exit handlers */
+	.handle_cop_unusable = kvm_trap_emul_handle_cop_unusable,
+	.handle_tlb_mod = kvm_trap_emul_handle_tlb_mod,
+	.handle_tlb_st_miss = kvm_trap_emul_handle_tlb_st_miss,
+	.handle_tlb_ld_miss = kvm_trap_emul_handle_tlb_ld_miss,
+	.handle_addr_err_st = kvm_trap_emul_handle_addr_err_st,
+	.handle_addr_err_ld = kvm_trap_emul_handle_addr_err_ld,
+	.handle_syscall = kvm_trap_emul_handle_syscall,
+	.handle_res_inst = kvm_trap_emul_handle_res_inst,
+	.handle_break = kvm_trap_emul_handle_break,
+	.handle_trap = kvm_trap_emul_handle_trap,
+	.handle_msa_fpe = kvm_trap_emul_handle_msa_fpe,
+	.handle_fpe = kvm_trap_emul_handle_fpe,
+	.handle_msa_disabled = kvm_trap_emul_handle_msa_disabled,
+	.handle_guest_exit = kvm_trap_emul_no_handler,
+
+	.hardware_enable = kvm_trap_emul_hardware_enable,
+	.hardware_disable = kvm_trap_emul_hardware_disable,
+	.check_extension = kvm_trap_emul_check_extension,
+	.vcpu_init = kvm_trap_emul_vcpu_init,
+	.vcpu_uninit = kvm_trap_emul_vcpu_uninit,
+	.vcpu_setup = kvm_trap_emul_vcpu_setup,
+	.flush_shadow_all = kvm_trap_emul_flush_shadow_all,
+	.flush_shadow_memslot = kvm_trap_emul_flush_shadow_memslot,
+	.gva_to_gpa = kvm_trap_emul_gva_to_gpa_cb,
+	.queue_timer_int = kvm_mips_queue_timer_int_cb,
+	.dequeue_timer_int = kvm_mips_dequeue_timer_int_cb,
+	.queue_io_int = kvm_mips_queue_io_int_cb,
+	.dequeue_io_int = kvm_mips_dequeue_io_int_cb,
+	.irq_deliver = kvm_mips_irq_deliver_cb,
+	.irq_clear = kvm_mips_irq_clear_cb,
+	.num_regs = kvm_trap_emul_num_regs,
+	.copy_reg_indices = kvm_trap_emul_copy_reg_indices,
+	.get_one_reg = kvm_trap_emul_get_one_reg,
+	.set_one_reg = kvm_trap_emul_set_one_reg,
+	.vcpu_load = kvm_trap_emul_vcpu_load,
+	.vcpu_put = kvm_trap_emul_vcpu_put,
+	.vcpu_run = kvm_trap_emul_vcpu_run,
+	.vcpu_reenter = kvm_trap_emul_vcpu_reenter,
+};
+
+int kvm_mips_emulation_init(struct kvm_mips_callbacks **install_callbacks)
+{
+	*install_callbacks = &kvm_trap_emul_callbacks;
+	return 0;
+}