KVM: MIPS: Implement VZ support

Add the main support for the MIPS Virtualization ASE (A.K.A. VZ) to MIPS
KVM. The bulk of this work is in vz.c, with various new state and
definitions elsewhere.

Enough is implemented to be able to run on a minimal VZ core. Further
patches will fill out support for guest features which are optional or
can be disabled.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Cc: linux-doc@vger.kernel.org

6 files changed, 2433 insertions, 0 deletions

diff --git a/arch/mips/kvm/interrupt.h b/arch/mips/kvm/interrupt.h
index fb118a2c8379..3bf0a49725e8 100644
--- a/arch/mips/kvm/interrupt.h
+++ b/arch/mips/kvm/interrupt.h
@@ -30,8 +30,13 @@
 
 #define C_TI        (_ULCAST_(1) << 30)
 
+#ifdef CONFIG_KVM_MIPS_VZ
+#define KVM_MIPS_IRQ_DELIVER_ALL_AT_ONCE (1)
+#define KVM_MIPS_IRQ_CLEAR_ALL_AT_ONCE   (1)
+#else
 #define KVM_MIPS_IRQ_DELIVER_ALL_AT_ONCE (0)
 #define KVM_MIPS_IRQ_CLEAR_ALL_AT_ONCE   (0)
+#endif
 
 void kvm_mips_queue_irq(struct kvm_vcpu *vcpu, unsigned int priority);
 void kvm_mips_dequeue_irq(struct kvm_vcpu *vcpu, unsigned int priority);
diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index 8c10148a345c..1bb5d01d5dec 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -113,7 +113,11 @@ void kvm_arch_check_processor_compat(void *rtn)
 int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 {
 	switch (type) {
+#ifdef CONFIG_KVM_MIPS_VZ
+	case KVM_VM_MIPS_VZ:
+#else
 	case KVM_VM_MIPS_TE:
+#endif
 		break;
 	default:
 		/* Unsupported KVM type */
@@ -378,6 +382,7 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id)
 
 	/* Init */
 	vcpu->arch.last_sched_cpu = -1;
+	vcpu->arch.last_exec_cpu = -1;
 
 	return vcpu;
 
diff --git a/arch/mips/kvm/mmu.c b/arch/mips/kvm/mmu.c
index cb0faade311e..ee64db032793 100644
--- a/arch/mips/kvm/mmu.c
+++ b/arch/mips/kvm/mmu.c
@@ -992,6 +992,22 @@ static pte_t kvm_mips_gpa_pte_to_gva_mapped(pte_t pte, long entrylo)
 	return kvm_mips_gpa_pte_to_gva_unmapped(pte);
 }
 
+#ifdef CONFIG_KVM_MIPS_VZ
+int kvm_mips_handle_vz_root_tlb_fault(unsigned long badvaddr,
+				      struct kvm_vcpu *vcpu,
+				      bool write_fault)
+{
+	int ret;
+
+	ret = kvm_mips_map_page(vcpu, badvaddr, write_fault, NULL, NULL);
+	if (ret)
+		return ret;
+
+	/* Invalidate this entry in the TLB */
+	return kvm_vz_host_tlb_inv(vcpu, badvaddr);
+}
+#endif
+
 /* XXXKYMA: Must be called with interrupts disabled */
 int kvm_mips_handle_kseg0_tlb_fault(unsigned long badvaddr,
 				    struct kvm_vcpu *vcpu,
@@ -1225,6 +1241,10 @@ int kvm_get_inst(u32 *opc, struct kvm_vcpu *vcpu, u32 *out)
 {
 	int err;
 
+	if (WARN(IS_ENABLED(CONFIG_KVM_MIPS_VZ),
+		 "Expect BadInstr/BadInstrP registers to be used with VZ\n"))
+		return -EINVAL;
+
 retry:
 	kvm_trap_emul_gva_lockless_begin(vcpu);
 	err = get_user(*out, opc);
diff --git a/arch/mips/kvm/tlb.c b/arch/mips/kvm/tlb.c
index a28fcb1e5072..c215470fdcb0 100644
--- a/arch/mips/kvm/tlb.c
+++ b/arch/mips/kvm/tlb.c
@@ -34,6 +34,13 @@
 #define KVM_GUEST_SP_TLB    1
 
 #ifdef CONFIG_KVM_MIPS_VZ
+unsigned long GUESTID_MASK;
+EXPORT_SYMBOL_GPL(GUESTID_MASK);
+unsigned long GUESTID_FIRST_VERSION;
+EXPORT_SYMBOL_GPL(GUESTID_FIRST_VERSION);
+unsigned long GUESTID_VERSION_MASK;
+EXPORT_SYMBOL_GPL(GUESTID_VERSION_MASK);
+
 static u32 kvm_mips_get_root_asid(struct kvm_vcpu *vcpu)
 {
 	struct mm_struct *gpa_mm = &vcpu->kvm->arch.gpa_mm;
diff --git a/arch/mips/kvm/trace.h b/arch/mips/kvm/trace.h
index 0c59282a2f7d..d80d37a1b82e 100644
--- a/arch/mips/kvm/trace.h
+++ b/arch/mips/kvm/trace.h
@@ -286,6 +286,21 @@ TRACE_EVENT(kvm_asid_change,
 		      __entry->new_asid)
 );
 
+TRACE_EVENT(kvm_guestid_change,
+	    TP_PROTO(struct kvm_vcpu *vcpu, unsigned int guestid),
+	    TP_ARGS(vcpu, guestid),
+	    TP_STRUCT__entry(
+			__field(unsigned int, guestid)
+	    ),
+
+	    TP_fast_assign(
+			__entry->guestid = guestid;
+	    ),
+
+	    TP_printk("GuestID: 0x%02x",
+		      __entry->guestid)
+);
+
 #endif /* _TRACE_KVM_H */
 
 /* This part must be outside protection */
diff --git a/arch/mips/kvm/vz.c b/arch/mips/kvm/vz.c
new file mode 100644
index 000000000000..cfed234be1e3
--- /dev/null
+++ b/arch/mips/kvm/vz.c
@@ -0,0 +1,2381 @@
+/*
+ * 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: Support for hardware virtualization extensions
+ *
+ * Copyright (C) 2012  MIPS Technologies, Inc.  All rights reserved.
+ * Authors: Yann Le Du <ledu@kymasys.com>
+ */
+
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/preempt.h>
+#include <linux/vmalloc.h>
+#include <asm/cacheflush.h>
+#include <asm/cacheops.h>
+#include <asm/cmpxchg.h>
+#include <asm/fpu.h>
+#include <asm/hazards.h>
+#include <asm/inst.h>
+#include <asm/mmu_context.h>
+#include <asm/r4kcache.h>
+#include <asm/time.h>
+#include <asm/tlb.h>
+#include <asm/tlbex.h>
+
+#include <linux/kvm_host.h>
+
+#include "interrupt.h"
+
+#include "trace.h"
+
+/* Pointers to last VCPU loaded on each physical CPU */
+static struct kvm_vcpu *last_vcpu[NR_CPUS];
+/* Pointers to last VCPU executed on each physical CPU */
+static struct kvm_vcpu *last_exec_vcpu[NR_CPUS];
+
+/*
+ * Number of guest VTLB entries to use, so we can catch inconsistency between
+ * CPUs.
+ */
+static unsigned int kvm_vz_guest_vtlb_size;
+
+static inline long kvm_vz_read_gc0_ebase(void)
+{
+	if (sizeof(long) == 8 && cpu_has_ebase_wg)
+		return read_gc0_ebase_64();
+	else
+		return read_gc0_ebase();
+}
+
+static inline void kvm_vz_write_gc0_ebase(long v)
+{
+	/*
+	 * First write with WG=1 to write upper bits, then write again in case
+	 * WG should be left at 0.
+	 * write_gc0_ebase_64() is no longer UNDEFINED since R6.
+	 */
+	if (sizeof(long) == 8 &&
+	    (cpu_has_mips64r6 || cpu_has_ebase_wg)) {
+		write_gc0_ebase_64(v | MIPS_EBASE_WG);
+		write_gc0_ebase_64(v);
+	} else {
+		write_gc0_ebase(v | MIPS_EBASE_WG);
+		write_gc0_ebase(v);
+	}
+}
+
+/*
+ * These Config bits may be writable by the guest:
+ * Config:	[K23, KU] (!TLB), K0
+ * Config1:	(none)
+ * Config2:	[TU, SU] (impl)
+ * Config3:	ISAOnExc
+ * Config4:	FTLBPageSize
+ * Config5:	K, CV, MSAEn, UFE, FRE, SBRI, UFR
+ */
+
+static inline unsigned int kvm_vz_config_guest_wrmask(struct kvm_vcpu *vcpu)
+{
+	return CONF_CM_CMASK;
+}
+
+static inline unsigned int kvm_vz_config1_guest_wrmask(struct kvm_vcpu *vcpu)
+{
+	return 0;
+}
+
+static inline unsigned int kvm_vz_config2_guest_wrmask(struct kvm_vcpu *vcpu)
+{
+	return 0;
+}
+
+static inline unsigned int kvm_vz_config3_guest_wrmask(struct kvm_vcpu *vcpu)
+{
+	return MIPS_CONF3_ISA_OE;
+}
+
+static inline unsigned int kvm_vz_config4_guest_wrmask(struct kvm_vcpu *vcpu)
+{
+	/* no need to be exact */
+	return MIPS_CONF4_VFTLBPAGESIZE;
+}
+
+static inline unsigned int kvm_vz_config5_guest_wrmask(struct kvm_vcpu *vcpu)
+{
+	unsigned int mask = MIPS_CONF5_K | MIPS_CONF5_CV | MIPS_CONF5_SBRI;
+
+	/* Permit MSAEn changes if MSA supported and enabled */
+	if (kvm_mips_guest_has_msa(&vcpu->arch))
+		mask |= MIPS_CONF5_MSAEN;
+
+	/*
+	 * Permit guest FPU mode changes if FPU is enabled and the relevant
+	 * feature exists according to FIR register.
+	 */
+	if (kvm_mips_guest_has_fpu(&vcpu->arch)) {
+		if (cpu_has_ufr)
+			mask |= MIPS_CONF5_UFR;
+		if (cpu_has_fre)
+			mask |= MIPS_CONF5_FRE | MIPS_CONF5_UFE;
+	}
+
+	return mask;
+}
+
+/*
+ * VZ optionally allows these additional Config bits to be written by root:
+ * Config:	M, [MT]
+ * Config1:	M, [MMUSize-1, C2, MD, PC, WR, CA], FP
+ * Config2:	M
+ * Config3:	M, MSAP, [BPG], ULRI, [DSP2P, DSPP, CTXTC, ITL, LPA, VEIC,
+ *		VInt, SP, CDMM, MT, SM, TL]
+ * Config4:	M, [VTLBSizeExt, MMUSizeExt]
+ * Config5:	[MRP]
+ */
+
+static inline unsigned int kvm_vz_config_user_wrmask(struct kvm_vcpu *vcpu)
+{
+	return kvm_vz_config_guest_wrmask(vcpu) | MIPS_CONF_M;
+}
+
+static inline unsigned int kvm_vz_config1_user_wrmask(struct kvm_vcpu *vcpu)
+{
+	unsigned int mask = kvm_vz_config1_guest_wrmask(vcpu) | MIPS_CONF_M;
+
+	/* Permit FPU to be present if FPU is supported */
+	if (kvm_mips_guest_can_have_fpu(&vcpu->arch))
+		mask |= MIPS_CONF1_FP;
+
+	return mask;
+}
+
+static inline unsigned int kvm_vz_config2_user_wrmask(struct kvm_vcpu *vcpu)
+{
+	return kvm_vz_config2_guest_wrmask(vcpu) | MIPS_CONF_M;
+}
+
+static inline unsigned int kvm_vz_config3_user_wrmask(struct kvm_vcpu *vcpu)
+{
+	unsigned int mask = kvm_vz_config3_guest_wrmask(vcpu) | MIPS_CONF_M |
+		MIPS_CONF3_ULRI;
+
+	/* Permit MSA to be present if MSA is supported */
+	if (kvm_mips_guest_can_have_msa(&vcpu->arch))
+		mask |= MIPS_CONF3_MSA;
+
+	return mask;
+}
+
+static inline unsigned int kvm_vz_config4_user_wrmask(struct kvm_vcpu *vcpu)
+{
+	return kvm_vz_config4_guest_wrmask(vcpu) | MIPS_CONF_M;
+}
+
+static inline unsigned int kvm_vz_config5_user_wrmask(struct kvm_vcpu *vcpu)
+{
+	return kvm_vz_config5_guest_wrmask(vcpu);
+}
+
+static gpa_t kvm_vz_gva_to_gpa_cb(gva_t gva)
+{
+	/* VZ guest has already converted gva to gpa */
+	return gva;
+}
+
+static void kvm_vz_queue_irq(struct kvm_vcpu *vcpu, unsigned int priority)
+{
+	set_bit(priority, &vcpu->arch.pending_exceptions);
+	clear_bit(priority, &vcpu->arch.pending_exceptions_clr);
+}
+
+static void kvm_vz_dequeue_irq(struct kvm_vcpu *vcpu, unsigned int priority)
+{
+	clear_bit(priority, &vcpu->arch.pending_exceptions);
+	set_bit(priority, &vcpu->arch.pending_exceptions_clr);
+}
+
+static void kvm_vz_queue_timer_int_cb(struct kvm_vcpu *vcpu)
+{
+	/*
+	 * timer expiry is asynchronous to vcpu execution therefore defer guest
+	 * cp0 accesses
+	 */
+	kvm_vz_queue_irq(vcpu, MIPS_EXC_INT_TIMER);
+}
+
+static void kvm_vz_dequeue_timer_int_cb(struct kvm_vcpu *vcpu)
+{
+	/*
+	 * timer expiry is asynchronous to vcpu execution therefore defer guest
+	 * cp0 accesses
+	 */
+	kvm_vz_dequeue_irq(vcpu, MIPS_EXC_INT_TIMER);
+}
+
+static void kvm_vz_queue_io_int_cb(struct kvm_vcpu *vcpu,
+				   struct kvm_mips_interrupt *irq)
+{
+	int intr = (int)irq->irq;
+
+	/*
+	 * interrupts are asynchronous to vcpu execution therefore defer guest
+	 * cp0 accesses
+	 */
+	switch (intr) {
+	case 2:
+		kvm_vz_queue_irq(vcpu, MIPS_EXC_INT_IO);
+		break;
+
+	case 3:
+		kvm_vz_queue_irq(vcpu, MIPS_EXC_INT_IPI_1);
+		break;
+
+	case 4:
+		kvm_vz_queue_irq(vcpu, MIPS_EXC_INT_IPI_2);
+		break;
+
+	default:
+		break;
+	}
+
+}
+
+static void kvm_vz_dequeue_io_int_cb(struct kvm_vcpu *vcpu,
+				     struct kvm_mips_interrupt *irq)
+{
+	int intr = (int)irq->irq;
+
+	/*
+	 * interrupts are asynchronous to vcpu execution therefore defer guest
+	 * cp0 accesses
+	 */
+	switch (intr) {
+	case -2:
+		kvm_vz_dequeue_irq(vcpu, MIPS_EXC_INT_IO);
+		break;
+
+	case -3:
+		kvm_vz_dequeue_irq(vcpu, MIPS_EXC_INT_IPI_1);
+		break;
+
+	case -4:
+		kvm_vz_dequeue_irq(vcpu, MIPS_EXC_INT_IPI_2);
+		break;
+
+	default:
+		break;
+	}
+
+}
+
+static u32 kvm_vz_priority_to_irq[MIPS_EXC_MAX] = {
+	[MIPS_EXC_INT_TIMER] = C_IRQ5,
+	[MIPS_EXC_INT_IO]    = C_IRQ0,
+	[MIPS_EXC_INT_IPI_1] = C_IRQ1,
+	[MIPS_EXC_INT_IPI_2] = C_IRQ2,
+};
+
+static int kvm_vz_irq_deliver_cb(struct kvm_vcpu *vcpu, unsigned int priority,
+				 u32 cause)
+{
+	u32 irq = (priority < MIPS_EXC_MAX) ?
+		kvm_vz_priority_to_irq[priority] : 0;
+
+	switch (priority) {
+	case MIPS_EXC_INT_TIMER:
+		set_gc0_cause(C_TI);
+		break;
+
+	case MIPS_EXC_INT_IO:
+	case MIPS_EXC_INT_IPI_1:
+	case MIPS_EXC_INT_IPI_2:
+		if (cpu_has_guestctl2)
+			set_c0_guestctl2(irq);
+		else
+			set_gc0_cause(irq);
+		break;
+
+	default:
+		break;
+	}
+
+	clear_bit(priority, &vcpu->arch.pending_exceptions);
+	return 1;
+}
+
+static int kvm_vz_irq_clear_cb(struct kvm_vcpu *vcpu, unsigned int priority,
+			       u32 cause)
+{
+	u32 irq = (priority < MIPS_EXC_MAX) ?
+		kvm_vz_priority_to_irq[priority] : 0;
+
+	switch (priority) {
+	case MIPS_EXC_INT_TIMER:
+		/*
+		 * Call to kvm_write_c0_guest_compare() clears Cause.TI in
+		 * kvm_mips_emulate_CP0(). Explicitly clear irq associated with
+		 * Cause.IP[IPTI] if GuestCtl2 virtual interrupt register not
+		 * supported or if not using GuestCtl2 Hardware Clear.
+		 */
+		if (cpu_has_guestctl2) {
+			if (!(read_c0_guestctl2() & (irq << 14)))
+				clear_c0_guestctl2(irq);
+		} else {
+			clear_gc0_cause(irq);
+		}
+		break;
+
+	case MIPS_EXC_INT_IO:
+	case MIPS_EXC_INT_IPI_1:
+	case MIPS_EXC_INT_IPI_2:
+		/* Clear GuestCtl2.VIP irq if not using Hardware Clear */
+		if (cpu_has_guestctl2) {
+			if (!(read_c0_guestctl2() & (irq << 14)))
+				clear_c0_guestctl2(irq);
+		} else {
+			clear_gc0_cause(irq);
+		}
+		break;
+
+	default:
+		break;
+	}
+
+	clear_bit(priority, &vcpu->arch.pending_exceptions_clr);
+	return 1;
+}
+
+/*
+ * VZ guest timer handling.
+ */
+
+/**
+ * _kvm_vz_restore_stimer() - Restore soft timer state.
+ * @vcpu:	Virtual CPU.
+ * @compare:	CP0_Compare register value, restored by caller.
+ * @cause:	CP0_Cause register to restore.
+ *
+ * Restore VZ state relating to the soft timer.
+ */
+static void _kvm_vz_restore_stimer(struct kvm_vcpu *vcpu, u32 compare,
+				   u32 cause)
+{
+	/*
+	 * Avoid spurious counter interrupts by setting Guest CP0_Count to just
+	 * after Guest CP0_Compare.
+	 */
+	write_c0_gtoffset(compare - read_c0_count());
+
+	back_to_back_c0_hazard();
+	write_gc0_cause(cause);
+}
+
+/**
+ * kvm_vz_restore_timer() - Restore guest timer state.
+ * @vcpu:	Virtual CPU.
+ *
+ * Restore soft timer state from saved context.
+ */
+static void kvm_vz_restore_timer(struct kvm_vcpu *vcpu)
+{
+	struct mips_coproc *cop0 = vcpu->arch.cop0;
+	u32 cause, compare;
+
+	compare = kvm_read_sw_gc0_compare(cop0);
+	cause = kvm_read_sw_gc0_cause(cop0);
+
+	write_gc0_compare(compare);
+	_kvm_vz_restore_stimer(vcpu, compare, cause);
+}
+
+/**
+ * kvm_vz_save_timer() - Save guest timer state.
+ * @vcpu:	Virtual CPU.
+ *
+ * Save VZ guest timer state.
+ */
+static void kvm_vz_save_timer(struct kvm_vcpu *vcpu)
+{
+	struct mips_coproc *cop0 = vcpu->arch.cop0;
+	u32 compare, cause;
+
+	compare = read_gc0_compare();
+	cause = read_gc0_cause();
+
+	/* save timer-related state to VCPU context */
+	kvm_write_sw_gc0_cause(cop0, cause);
+	kvm_write_sw_gc0_compare(cop0, compare);
+}
+
+/**
+ * kvm_vz_gva_to_gpa() - Convert valid GVA to GPA.
+ * @vcpu:	KVM VCPU state.
+ * @gva:	Guest virtual address to convert.
+ * @gpa:	Output guest physical address.
+ *
+ * Convert a guest virtual address (GVA) which is valid according to the guest
+ * context, to a guest physical address (GPA).
+ *
+ * Returns:	0 on success.
+ *		-errno on failure.
+ */
+static int kvm_vz_gva_to_gpa(struct kvm_vcpu *vcpu, unsigned long gva,
+			     unsigned long *gpa)
+{
+	u32 gva32 = gva;
+
+	if ((long)gva == (s32)gva32) {
+		/* Handle canonical 32-bit virtual address */
+		if ((s32)gva32 < (s32)0xc0000000) {
+			/* legacy unmapped KSeg0 or KSeg1 */
+			*gpa = gva32 & 0x1fffffff;
+			return 0;
+		}
+#ifdef CONFIG_64BIT
+	} else if ((gva & 0xc000000000000000) == 0x8000000000000000) {
+		/* XKPHYS */
+		/*
+		 * Traditionally fully unmapped.
+		 * Bits 61:59 specify the CCA, which we can just mask off here.
+		 * Bits 58:PABITS should be zero, but we shouldn't have got here
+		 * if it wasn't.
+		 */
+		*gpa = gva & 0x07ffffffffffffff;
+		return 0;
+#endif
+	}
+
+	return kvm_vz_guest_tlb_lookup(vcpu, gva, gpa);
+}
+
+/**
+ * kvm_vz_badvaddr_to_gpa() - Convert GVA BadVAddr from root exception to GPA.
+ * @vcpu:	KVM VCPU state.
+ * @badvaddr:	Root BadVAddr.
+ * @gpa:	Output guest physical address.
+ *
+ * VZ implementations are permitted to report guest virtual addresses (GVA) in
+ * BadVAddr on a root exception during guest execution, instead of the more
+ * convenient guest physical addresses (GPA). When we get a GVA, this function
+ * converts it to a GPA, taking into account guest segmentation and guest TLB
+ * state.
+ *
+ * Returns:	0 on success.
+ *		-errno on failure.
+ */
+static int kvm_vz_badvaddr_to_gpa(struct kvm_vcpu *vcpu, unsigned long badvaddr,
+				  unsigned long *gpa)
+{
+	unsigned int gexccode = (vcpu->arch.host_cp0_guestctl0 &
+				 MIPS_GCTL0_GEXC) >> MIPS_GCTL0_GEXC_SHIFT;
+
+	/* If BadVAddr is GPA, then all is well in the world */
+	if (likely(gexccode == MIPS_GCTL0_GEXC_GPA)) {
+		*gpa = badvaddr;
+		return 0;
+	}
+
+	/* Otherwise we'd expect it to be GVA ... */
+	if (WARN(gexccode != MIPS_GCTL0_GEXC_GVA,
+		 "Unexpected gexccode %#x\n", gexccode))
+		return -EINVAL;
+
+	/* ... and we need to perform the GVA->GPA translation in software */
+	return kvm_vz_gva_to_gpa(vcpu, badvaddr, gpa);
+}
+
+static int kvm_trap_vz_no_handler(struct kvm_vcpu *vcpu)
+{
+	u32 *opc = (u32 *) 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,
+		read_gc0_status());
+	kvm_arch_vcpu_dump_regs(vcpu);
+	vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+	return RESUME_HOST;
+}
+
+static enum emulation_result kvm_vz_gpsi_cop0(union mips_instruction inst,
+					      u32 *opc, u32 cause,
+					      struct kvm_run *run,
+					      struct kvm_vcpu *vcpu)
+{
+	struct mips_coproc *cop0 = vcpu->arch.cop0;
+	enum emulation_result er = EMULATE_DONE;
+	u32 rt, rd, sel;
+	unsigned long curr_pc;
+	unsigned long val;
+
+	/*
+	 * Update PC and hold onto current PC in case there is
+	 * an error and we want to rollback the PC
+	 */
+	curr_pc = vcpu->arch.pc;
+	er = update_pc(vcpu, cause);
+	if (er == EMULATE_FAIL)
+		return er;
+
+	if (inst.co_format.co) {
+		switch (inst.co_format.func) {
+		case wait_op:
+			er = kvm_mips_emul_wait(vcpu);
+			break;
+		default:
+			er = EMULATE_FAIL;
+		}
+	} else {
+		rt = inst.c0r_format.rt;
+		rd = inst.c0r_format.rd;
+		sel = inst.c0r_format.sel;
+
+		switch (inst.c0r_format.rs) {
+		case dmfc_op:
+		case mfc_op:
+#ifdef CONFIG_KVM_MIPS_DEBUG_COP0_COUNTERS
+			cop0->stat[rd][sel]++;
+#endif
+			if (rd == MIPS_CP0_COUNT &&
+			    sel == 0) {			/* Count */
+				val = kvm_mips_read_count(vcpu);
+			} else if (rd == MIPS_CP0_COMPARE &&
+				   sel == 0) {		/* Compare */
+				val = read_gc0_compare();
+			} else if ((rd == MIPS_CP0_PRID &&
+				    (sel == 0 ||	/* PRid */
+				     sel == 2 ||	/* CDMMBase */
+				     sel == 3)) ||	/* CMGCRBase */
+				   (rd == MIPS_CP0_STATUS &&
+				    (sel == 2 ||	/* SRSCtl */
+				     sel == 3)) ||	/* SRSMap */
+				   (rd == MIPS_CP0_CONFIG &&
+				    (sel == 7)) ||	/* Config7 */
+				   (rd == MIPS_CP0_ERRCTL &&
+				    (sel == 0))) {	/* ErrCtl */
+				val = cop0->reg[rd][sel];
+			} else {
+				val = 0;
+				er = EMULATE_FAIL;
+			}
+
+			if (er != EMULATE_FAIL) {
+				/* Sign extend */
+				if (inst.c0r_format.rs == mfc_op)
+					val = (int)val;
+				vcpu->arch.gprs[rt] = val;
+			}
+
+			trace_kvm_hwr(vcpu, (inst.c0r_format.rs == mfc_op) ?
+					KVM_TRACE_MFC0 : KVM_TRACE_DMFC0,
+				      KVM_TRACE_COP0(rd, sel), val);
+			break;
+
+		case dmtc_op:
+		case mtc_op:
+#ifdef CONFIG_KVM_MIPS_DEBUG_COP0_COUNTERS
+			cop0->stat[rd][sel]++;
+#endif
+			val = vcpu->arch.gprs[rt];
+			trace_kvm_hwr(vcpu, (inst.c0r_format.rs == mtc_op) ?
+					KVM_TRACE_MTC0 : KVM_TRACE_DMTC0,
+				      KVM_TRACE_COP0(rd, sel), val);
+
+			if (rd == MIPS_CP0_COUNT &&
+			    sel == 0) {			/* Count */
+				kvm_mips_write_count(vcpu, vcpu->arch.gprs[rt]);
+			} else if (rd == MIPS_CP0_COMPARE &&
+				   sel == 0) {		/* Compare */
+				kvm_mips_write_compare(vcpu,
+						       vcpu->arch.gprs[rt],
+						       true);
+			} else if (rd == MIPS_CP0_ERRCTL &&
+				   (sel == 0)) {	/* ErrCtl */
+				/* ignore the written value */
+			} else {
+				er = EMULATE_FAIL;
+			}
+			break;
+
+		default:
+			er = EMULATE_FAIL;
+			break;
+		}
+	}
+	/* Rollback PC only if emulation was unsuccessful */
+	if (er == EMULATE_FAIL) {
+		kvm_err("[%#lx]%s: unsupported cop0 instruction 0x%08x\n",
+			curr_pc, __func__, inst.word);
+
+		vcpu->arch.pc = curr_pc;
+	}
+
+	return er;
+}
+
+static enum emulation_result kvm_vz_gpsi_cache(union mips_instruction inst,
+					       u32 *opc, u32 cause,
+					       struct kvm_run *run,
+					       struct kvm_vcpu *vcpu)
+{
+	enum emulation_result er = EMULATE_DONE;
+	u32 cache, op_inst, op, base;
+	s16 offset;
+	struct kvm_vcpu_arch *arch = &vcpu->arch;
+	unsigned long va, curr_pc;
+
+	/*
+	 * Update PC and hold onto current PC in case there is
+	 * an error and we want to rollback the PC
+	 */
+	curr_pc = vcpu->arch.pc;
+	er = update_pc(vcpu, cause);
+	if (er == EMULATE_FAIL)
+		return er;
+
+	base = inst.i_format.rs;
+	op_inst = inst.i_format.rt;
+	if (cpu_has_mips_r6)
+		offset = inst.spec3_format.simmediate;
+	else
+		offset = inst.i_format.simmediate;
+	cache = op_inst & CacheOp_Cache;
+	op = op_inst & CacheOp_Op;
+
+	va = arch->gprs[base] + offset;
+
+	kvm_debug("CACHE (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n",
+		  cache, op, base, arch->gprs[base], offset);
+
+	/* Secondary or tirtiary cache ops ignored */
+	if (cache != Cache_I && cache != Cache_D)
+		return EMULATE_DONE;
+
+	switch (op_inst) {
+	case Index_Invalidate_I:
+		flush_icache_line_indexed(va);
+		return EMULATE_DONE;
+	case Index_Writeback_Inv_D:
+		flush_dcache_line_indexed(va);
+		return EMULATE_DONE;
+	default:
+		break;
+	};
+
+	kvm_err("@ %#lx/%#lx CACHE (cache: %#x, op: %#x, base[%d]: %#lx, offset: %#x\n",
+		curr_pc, vcpu->arch.gprs[31], cache, op, base, arch->gprs[base],
+		offset);
+	/* Rollback PC */
+	vcpu->arch.pc = curr_pc;
+
+	return EMULATE_FAIL;
+}
+
+static enum emulation_result kvm_trap_vz_handle_gpsi(u32 cause, u32 *opc,
+						     struct kvm_vcpu *vcpu)
+{
+	enum emulation_result er = EMULATE_DONE;
+	struct kvm_vcpu_arch *arch = &vcpu->arch;
+	struct kvm_run *run = vcpu->run;
+	union mips_instruction inst;
+	int rd, rt, sel;
+	int err;
+
+	/*
+	 *  Fetch the instruction.
+	 */
+	if (cause & CAUSEF_BD)
+		opc += 1;
+	err = kvm_get_badinstr(opc, vcpu, &inst.word);
+	if (err)
+		return EMULATE_FAIL;
+
+	switch (inst.r_format.opcode) {
+	case cop0_op:
+		er = kvm_vz_gpsi_cop0(inst, opc, cause, run, vcpu);
+		break;
+#ifndef CONFIG_CPU_MIPSR6
+	case cache_op:
+		trace_kvm_exit(vcpu, KVM_TRACE_EXIT_CACHE);
+		er = kvm_vz_gpsi_cache(inst, opc, cause, run, vcpu);
+		break;
+#endif
+	case spec3_op:
+		switch (inst.spec3_format.func) {
+#ifdef CONFIG_CPU_MIPSR6
+		case cache6_op:
+			trace_kvm_exit(vcpu, KVM_TRACE_EXIT_CACHE);
+			er = kvm_vz_gpsi_cache(inst, opc, cause, run, vcpu);
+			break;
+#endif
+		case rdhwr_op:
+			if (inst.r_format.rs || (inst.r_format.re >> 3))
+				goto unknown;
+
+			rd = inst.r_format.rd;
+			rt = inst.r_format.rt;
+			sel = inst.r_format.re & 0x7;
+
+			switch (rd) {
+			case MIPS_HWR_CC:	/* Read count register */
+				arch->gprs[rt] =
+					(long)(int)kvm_mips_read_count(vcpu);
+				break;
+			default:
+				trace_kvm_hwr(vcpu, KVM_TRACE_RDHWR,
+					      KVM_TRACE_HWR(rd, sel), 0);
+				goto unknown;
+			};
+
+			trace_kvm_hwr(vcpu, KVM_TRACE_RDHWR,
+				      KVM_TRACE_HWR(rd, sel), arch->gprs[rt]);
+
+			er = update_pc(vcpu, cause);
+			break;
+		default:
+			goto unknown;
+		};
+		break;
+unknown:
+
+	default:
+		kvm_err("GPSI exception not supported (%p/%#x)\n",
+				opc, inst.word);
+		kvm_arch_vcpu_dump_regs(vcpu);
+		er = EMULATE_FAIL;
+		break;
+	}
+
+	return er;
+}
+
+static enum emulation_result kvm_trap_vz_handle_gsfc(u32 cause, u32 *opc,
+						     struct kvm_vcpu *vcpu)
+{
+	enum emulation_result er = EMULATE_DONE;
+	struct kvm_vcpu_arch *arch = &vcpu->arch;
+	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)
+		return EMULATE_FAIL;
+
+	/* complete MTC0 on behalf of guest and advance EPC */
+	if (inst.c0r_format.opcode == cop0_op &&
+	    inst.c0r_format.rs == mtc_op &&
+	    inst.c0r_format.z == 0) {
+		int rt = inst.c0r_format.rt;
+		int rd = inst.c0r_format.rd;
+		int sel = inst.c0r_format.sel;
+		unsigned int val = arch->gprs[rt];
+		unsigned int old_val, change;
+
+		trace_kvm_hwr(vcpu, KVM_TRACE_MTC0, KVM_TRACE_COP0(rd, sel),
+			      val);
+
+		if ((rd == MIPS_CP0_STATUS) && (sel == 0)) {
+			/* FR bit should read as zero if no FPU */
+			if (!kvm_mips_guest_has_fpu(&vcpu->arch))
+				val &= ~(ST0_CU1 | ST0_FR);
+
+			/*
+			 * Also don't allow FR to be set if host doesn't support
+			 * it.
+			 */
+			if (!(boot_cpu_data.fpu_id & MIPS_FPIR_F64))
+				val &= ~ST0_FR;
+
+			old_val = read_gc0_status();
+			change = val ^ old_val;
+
+			if (change & ST0_FR) {
+				/*
+				 * FPU and Vector register state is made
+				 * UNPREDICTABLE by a change of FR, so don't
+				 * even bother saving it.
+				 */
+				kvm_drop_fpu(vcpu);
+			}
+
+			/*
+			 * If MSA state is already live, it is undefined how it
+			 * interacts with FR=0 FPU state, and we don't want to
+			 * hit reserved instruction exceptions trying to save
+			 * the MSA state later when CU=1 && FR=1, so play it
+			 * safe and save it first.
+			 */
+			if (change & ST0_CU1 && !(val & ST0_FR) &&
+			    vcpu->arch.aux_inuse & KVM_MIPS_AUX_MSA)
+				kvm_lose_fpu(vcpu);
+
+			write_gc0_status(val);
+		} else if ((rd == MIPS_CP0_CAUSE) && (sel == 0)) {
+			u32 old_cause = read_gc0_cause();
+			u32 change = old_cause ^ val;
+
+			/* DC bit enabling/disabling timer? */
+			if (change & CAUSEF_DC) {
+				if (val & CAUSEF_DC)
+					kvm_mips_count_disable_cause(vcpu);
+				else
+					kvm_mips_count_enable_cause(vcpu);
+			}
+
+			/* Only certain bits are RW to the guest */
+			change &= (CAUSEF_DC | CAUSEF_IV | CAUSEF_WP |
+				   CAUSEF_IP0 | CAUSEF_IP1);
+
+			/* WP can only be cleared */
+			change &= ~CAUSEF_WP | old_cause;
+
+			write_gc0_cause(old_cause ^ change);
+		} else if ((rd == MIPS_CP0_STATUS) && (sel == 1)) { /* IntCtl */
+			write_gc0_intctl(val);
+		} else if ((rd == MIPS_CP0_CONFIG) && (sel == 5)) {
+			old_val = read_gc0_config5();
+			change = val ^ old_val;
+			/* Handle changes in FPU/MSA modes */
+			preempt_disable();
+
+			/*
+			 * Propagate FRE changes immediately if the FPU
+			 * context is already loaded.
+			 */
+			if (change & MIPS_CONF5_FRE &&
+			    vcpu->arch.aux_inuse & KVM_MIPS_AUX_FPU)
+				change_c0_config5(MIPS_CONF5_FRE, val);
+
+			preempt_enable();
+
+			val = old_val ^
+				(change & kvm_vz_config5_guest_wrmask(vcpu));
+			write_gc0_config5(val);
+		} else {
+			kvm_err("Handle GSFC, unsupported field change @ %p: %#x\n",
+			    opc, inst.word);
+			er = EMULATE_FAIL;
+		}
+
+		if (er != EMULATE_FAIL)
+			er = update_pc(vcpu, cause);
+	} else {
+		kvm_err("Handle GSFC, unrecognized instruction @ %p: %#x\n",
+			opc, inst.word);
+		er = EMULATE_FAIL;
+	}
+
+	return er;
+}
+
+static enum emulation_result kvm_trap_vz_handle_hc(u32 cause, u32 *opc,
+						   struct kvm_vcpu *vcpu)
+{
+	enum emulation_result er;
+	union mips_instruction inst;
+	unsigned long curr_pc;
+	int err;
+
+	if (cause & CAUSEF_BD)
+		opc += 1;
+	err = kvm_get_badinstr(opc, vcpu, &inst.word);
+	if (err)
+		return EMULATE_FAIL;
+
+	/*
+	 * Update PC and hold onto current PC in case there is
+	 * an error and we want to rollback the PC
+	 */
+	curr_pc = vcpu->arch.pc;
+	er = update_pc(vcpu, cause);
+	if (er == EMULATE_FAIL)
+		return er;
+
+	er = kvm_mips_emul_hypcall(vcpu, inst);
+	if (er == EMULATE_FAIL)
+		vcpu->arch.pc = curr_pc;
+
+	return er;
+}
+
+static enum emulation_result kvm_trap_vz_no_handler_guest_exit(u32 gexccode,
+							u32 cause,
+							u32 *opc,
+							struct kvm_vcpu *vcpu)
+{
+	u32 inst;
+
+	/*
+	 *  Fetch the instruction.
+	 */
+	if (cause & CAUSEF_BD)
+		opc += 1;
+	kvm_get_badinstr(opc, vcpu, &inst);
+
+	kvm_err("Guest Exception Code: %d not yet handled @ PC: %p, inst: 0x%08x  Status: %#x\n",
+		gexccode, opc, inst, read_gc0_status());
+
+	return EMULATE_FAIL;
+}
+
+static int kvm_trap_vz_handle_guest_exit(struct kvm_vcpu *vcpu)
+{
+	u32 *opc = (u32 *) vcpu->arch.pc;
+	u32 cause = vcpu->arch.host_cp0_cause;
+	enum emulation_result er = EMULATE_DONE;
+	u32 gexccode = (vcpu->arch.host_cp0_guestctl0 &
+			MIPS_GCTL0_GEXC) >> MIPS_GCTL0_GEXC_SHIFT;
+	int ret = RESUME_GUEST;
+
+	trace_kvm_exit(vcpu, KVM_TRACE_EXIT_GEXCCODE_BASE + gexccode);
+	switch (gexccode) {
+	case MIPS_GCTL0_GEXC_GPSI:
+		++vcpu->stat.vz_gpsi_exits;
+		er = kvm_trap_vz_handle_gpsi(cause, opc, vcpu);
+		break;
+	case MIPS_GCTL0_GEXC_GSFC:
+		++vcpu->stat.vz_gsfc_exits;
+		er = kvm_trap_vz_handle_gsfc(cause, opc, vcpu);
+		break;
+	case MIPS_GCTL0_GEXC_HC:
+		++vcpu->stat.vz_hc_exits;
+		er = kvm_trap_vz_handle_hc(cause, opc, vcpu);
+		break;
+	case MIPS_GCTL0_GEXC_GRR:
+		++vcpu->stat.vz_grr_exits;
+		er = kvm_trap_vz_no_handler_guest_exit(gexccode, cause, opc,
+						       vcpu);
+		break;
+	case MIPS_GCTL0_GEXC_GVA:
+		++vcpu->stat.vz_gva_exits;
+		er = kvm_trap_vz_no_handler_guest_exit(gexccode, cause, opc,
+						       vcpu);
+		break;
+	case MIPS_GCTL0_GEXC_GHFC:
+		++vcpu->stat.vz_ghfc_exits;
+		er = kvm_trap_vz_no_handler_guest_exit(gexccode, cause, opc,
+						       vcpu);
+		break;
+	case MIPS_GCTL0_GEXC_GPA:
+		++vcpu->stat.vz_gpa_exits;
+		er = kvm_trap_vz_no_handler_guest_exit(gexccode, cause, opc,
+						       vcpu);
+		break;
+	default:
+		++vcpu->stat.vz_resvd_exits;
+		er = kvm_trap_vz_no_handler_guest_exit(gexccode, cause, opc,
+						       vcpu);
+		break;
+
+	}
+
+	if (er == EMULATE_DONE) {
+		ret = RESUME_GUEST;
+	} else if (er == EMULATE_HYPERCALL) {
+		ret = kvm_mips_handle_hypcall(vcpu);
+	} else {
+		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+		ret = RESUME_HOST;
+	}
+	return ret;
+}
+
+/**
+ * kvm_trap_vz_handle_cop_unusuable() - Guest used unusable coprocessor.
+ * @vcpu:	Virtual CPU context.
+ *
+ * Handle when the guest attempts to use a coprocessor which hasn't been allowed
+ * by the root context.
+ */
+static int kvm_trap_vz_handle_cop_unusable(struct kvm_vcpu *vcpu)
+{
+	struct kvm_run *run = vcpu->run;
+	u32 cause = vcpu->arch.host_cp0_cause;
+	enum emulation_result er = EMULATE_FAIL;
+	int ret = RESUME_GUEST;
+
+	if (((cause & CAUSEF_CE) >> CAUSEB_CE) == 1) {
+		/*
+		 * If guest FPU not present, the FPU operation should have been
+		 * treated as a reserved instruction!
+		 * If FPU already in use, we shouldn't get this at all.
+		 */
+		if (WARN_ON(!kvm_mips_guest_has_fpu(&vcpu->arch) ||
+			    vcpu->arch.aux_inuse & KVM_MIPS_AUX_FPU)) {
+			preempt_enable();
+			return EMULATE_FAIL;
+		}
+
+		kvm_own_fpu(vcpu);
+		er = EMULATE_DONE;
+	}
+	/* other coprocessors not handled */
+
+	switch (er) {
+	case EMULATE_DONE:
+		ret = RESUME_GUEST;
+		break;
+
+	case EMULATE_FAIL:
+		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+		ret = RESUME_HOST;
+		break;
+
+	default:
+		BUG();
+	}
+	return ret;
+}
+
+/**
+ * kvm_trap_vz_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 in the root
+ * context.
+ */
+static int kvm_trap_vz_handle_msa_disabled(struct kvm_vcpu *vcpu)
+{
+	struct kvm_run *run = vcpu->run;
+
+	/*
+	 * If MSA not present or not exposed to guest or FR=0, the MSA operation
+	 * should have been treated as a reserved instruction!
+	 * Same if CU1=1, FR=0.
+	 * If MSA already in use, we shouldn't get this at all.
+	 */
+	if (!kvm_mips_guest_has_msa(&vcpu->arch) ||
+	    (read_gc0_status() & (ST0_CU1 | ST0_FR)) == ST0_CU1 ||
+	    !(read_gc0_config5() & MIPS_CONF5_MSAEN) ||
+	    vcpu->arch.aux_inuse & KVM_MIPS_AUX_MSA) {
+		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+		return RESUME_HOST;
+	}
+
+	kvm_own_msa(vcpu);
+
+	return RESUME_GUEST;
+}
+
+static int kvm_trap_vz_handle_tlb_ld_miss(struct kvm_vcpu *vcpu)
+{
+	struct kvm_run *run = vcpu->run;
+	u32 *opc = (u32 *) vcpu->arch.pc;
+	u32 cause = vcpu->arch.host_cp0_cause;
+	ulong badvaddr = vcpu->arch.host_cp0_badvaddr;
+	union mips_instruction inst;
+	enum emulation_result er = EMULATE_DONE;
+	int err, ret = RESUME_GUEST;
+
+	if (kvm_mips_handle_vz_root_tlb_fault(badvaddr, vcpu, false)) {
+		/* A code fetch fault doesn't count as an MMIO */
+		if (kvm_is_ifetch_fault(&vcpu->arch)) {
+			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) {
+			run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+			return RESUME_HOST;
+		}
+
+		/* Treat as MMIO */
+		er = kvm_mips_emulate_load(inst, cause, run, vcpu);
+		if (er == EMULATE_FAIL) {
+			kvm_err("Guest Emulate Load from MMIO space failed: PC: %p, BadVaddr: %#lx\n",
+				opc, badvaddr);
+			run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+		}
+	}
+
+	if (er == EMULATE_DONE) {
+		ret = RESUME_GUEST;
+	} else if (er == EMULATE_DO_MMIO) {
+		run->exit_reason = KVM_EXIT_MMIO;
+		ret = RESUME_HOST;
+	} else {
+		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+		ret = RESUME_HOST;
+	}
+	return ret;
+}
+
+static int kvm_trap_vz_handle_tlb_st_miss(struct kvm_vcpu *vcpu)
+{
+	struct kvm_run *run = vcpu->run;
+	u32 *opc = (u32 *) vcpu->arch.pc;
+	u32 cause = vcpu->arch.host_cp0_cause;
+	ulong badvaddr = vcpu->arch.host_cp0_badvaddr;
+	union mips_instruction inst;
+	enum emulation_result er = EMULATE_DONE;
+	int err;
+	int ret = RESUME_GUEST;
+
+	/* Just try the access again if we couldn't do the translation */
+	if (kvm_vz_badvaddr_to_gpa(vcpu, badvaddr, &badvaddr))
+		return RESUME_GUEST;
+	vcpu->arch.host_cp0_badvaddr = badvaddr;
+
+	if (kvm_mips_handle_vz_root_tlb_fault(badvaddr, vcpu, true)) {
+		/* Fetch the instruction */
+		if (cause & CAUSEF_BD)
+			opc += 1;
+		err = kvm_get_badinstr(opc, vcpu, &inst.word);
+		if (err) {
+			run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+			return RESUME_HOST;
+		}
+
+		/* Treat as MMIO */
+		er = kvm_mips_emulate_store(inst, cause, run, vcpu);
+		if (er == EMULATE_FAIL) {
+			kvm_err("Guest Emulate Store to MMIO space failed: PC: %p, BadVaddr: %#lx\n",
+				opc, badvaddr);
+			run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+		}
+	}
+
+	if (er == EMULATE_DONE) {
+		ret = RESUME_GUEST;
+	} else if (er == EMULATE_DO_MMIO) {
+		run->exit_reason = KVM_EXIT_MMIO;
+		ret = RESUME_HOST;
+	} else {
+		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+		ret = RESUME_HOST;
+	}
+	return ret;
+}
+
+static u64 kvm_vz_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_PAGEMASK,
+	KVM_REG_MIPS_CP0_PAGEGRAIN,
+	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,
+#ifdef CONFIG_64BIT
+	KVM_REG_MIPS_CP0_XCONTEXT,
+#endif
+	KVM_REG_MIPS_CP0_ERROREPC,
+
+	KVM_REG_MIPS_COUNT_CTL,
+	KVM_REG_MIPS_COUNT_RESUME,
+	KVM_REG_MIPS_COUNT_HZ,
+};
+
+static u64 kvm_vz_get_one_regs_kscratch[] = {
+	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,
+};
+
+static unsigned long kvm_vz_num_regs(struct kvm_vcpu *vcpu)
+{
+	unsigned long ret;
+
+	ret = ARRAY_SIZE(kvm_vz_get_one_regs);
+	if (cpu_guest_has_userlocal)
+		++ret;
+	ret += __arch_hweight8(cpu_data[0].guest.kscratch_mask);
+
+	return ret;
+}
+
+static int kvm_vz_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *indices)
+{
+	u64 index;
+	unsigned int i;
+
+	if (copy_to_user(indices, kvm_vz_get_one_regs,
+			 sizeof(kvm_vz_get_one_regs)))
+		return -EFAULT;
+	indices += ARRAY_SIZE(kvm_vz_get_one_regs);
+
+	if (cpu_guest_has_userlocal) {
+		index = KVM_REG_MIPS_CP0_USERLOCAL;
+		if (copy_to_user(indices, &index, sizeof(index)))
+			return -EFAULT;
+		++indices;
+	}
+	for (i = 0; i < 6; ++i) {
+		if (!cpu_guest_has_kscr(i + 2))
+			continue;
+
+		if (copy_to_user(indices, &kvm_vz_get_one_regs_kscratch[i],
+				 sizeof(kvm_vz_get_one_regs_kscratch[i])))
+			return -EFAULT;
+		++indices;
+	}
+
+	return 0;
+}
+
+static inline s64 entrylo_kvm_to_user(unsigned long v)
+{
+	s64 mask, ret = v;
+
+	if (BITS_PER_LONG == 32) {
+		/*
+		 * KVM API exposes 64-bit version of the register, so move the
+		 * RI/XI bits up into place.
+		 */
+		mask = MIPS_ENTRYLO_RI | MIPS_ENTRYLO_XI;
+		ret &= ~mask;
+		ret |= ((s64)v & mask) << 32;
+	}
+	return ret;
+}
+
+static inline unsigned long entrylo_user_to_kvm(s64 v)
+{
+	unsigned long mask, ret = v;
+
+	if (BITS_PER_LONG == 32) {
+		/*
+		 * KVM API exposes 64-bit versiono of the register, so move the
+		 * RI/XI bits down into place.
+		 */
+		mask = MIPS_ENTRYLO_RI | MIPS_ENTRYLO_XI;
+		ret &= ~mask;
+		ret |= (v >> 32) & mask;
+	}
+	return ret;
+}
+
+static int kvm_vz_get_one_reg(struct kvm_vcpu *vcpu,
+			      const struct kvm_one_reg *reg,
+			      s64 *v)
+{
+	struct mips_coproc *cop0 = vcpu->arch.cop0;
+	unsigned int idx;
+
+	switch (reg->id) {
+	case KVM_REG_MIPS_CP0_INDEX:
+		*v = (long)read_gc0_index();
+		break;
+	case KVM_REG_MIPS_CP0_ENTRYLO0:
+		*v = entrylo_kvm_to_user(read_gc0_entrylo0());
+		break;
+	case KVM_REG_MIPS_CP0_ENTRYLO1:
+		*v = entrylo_kvm_to_user(read_gc0_entrylo1());
+		break;
+	case KVM_REG_MIPS_CP0_CONTEXT:
+		*v = (long)read_gc0_context();
+		break;
+	case KVM_REG_MIPS_CP0_USERLOCAL:
+		if (!cpu_guest_has_userlocal)
+			return -EINVAL;
+		*v = read_gc0_userlocal();
+		break;
+	case KVM_REG_MIPS_CP0_PAGEMASK:
+		*v = (long)read_gc0_pagemask();
+		break;
+	case KVM_REG_MIPS_CP0_PAGEGRAIN:
+		*v = (long)read_gc0_pagegrain();
+		break;
+	case KVM_REG_MIPS_CP0_WIRED:
+		*v = (long)read_gc0_wired();
+		break;
+	case KVM_REG_MIPS_CP0_HWRENA:
+		*v = (long)read_gc0_hwrena();
+		break;
+	case KVM_REG_MIPS_CP0_BADVADDR:
+		*v = (long)read_gc0_badvaddr();
+		break;
+	case KVM_REG_MIPS_CP0_COUNT:
+		*v = kvm_mips_read_count(vcpu);
+		break;
+	case KVM_REG_MIPS_CP0_ENTRYHI:
+		*v = (long)read_gc0_entryhi();
+		break;
+	case KVM_REG_MIPS_CP0_COMPARE:
+		*v = (long)read_gc0_compare();
+		break;
+	case KVM_REG_MIPS_CP0_STATUS:
+		*v = (long)read_gc0_status();
+		break;
+	case KVM_REG_MIPS_CP0_INTCTL:
+		*v = read_gc0_intctl();
+		break;
+	case KVM_REG_MIPS_CP0_CAUSE:
+		*v = (long)read_gc0_cause();
+		break;
+	case KVM_REG_MIPS_CP0_EPC:
+		*v = (long)read_gc0_epc();
+		break;
+	case KVM_REG_MIPS_CP0_PRID:
+		*v = (long)kvm_read_c0_guest_prid(cop0);
+		break;
+	case KVM_REG_MIPS_CP0_EBASE:
+		*v = kvm_vz_read_gc0_ebase();
+		break;
+	case KVM_REG_MIPS_CP0_CONFIG:
+		*v = read_gc0_config();
+		break;
+	case KVM_REG_MIPS_CP0_CONFIG1:
+		if (!cpu_guest_has_conf1)
+			return -EINVAL;
+		*v = read_gc0_config1();
+		break;
+	case KVM_REG_MIPS_CP0_CONFIG2:
+		if (!cpu_guest_has_conf2)
+			return -EINVAL;
+		*v = read_gc0_config2();
+		break;
+	case KVM_REG_MIPS_CP0_CONFIG3:
+		if (!cpu_guest_has_conf3)
+			return -EINVAL;
+		*v = read_gc0_config3();
+		break;
+	case KVM_REG_MIPS_CP0_CONFIG4:
+		if (!cpu_guest_has_conf4)
+			return -EINVAL;
+		*v = read_gc0_config4();
+		break;
+	case KVM_REG_MIPS_CP0_CONFIG5:
+		if (!cpu_guest_has_conf5)
+			return -EINVAL;
+		*v = read_gc0_config5();
+		break;
+#ifdef CONFIG_64BIT
+	case KVM_REG_MIPS_CP0_XCONTEXT:
+		*v = read_gc0_xcontext();
+		break;
+#endif
+	case KVM_REG_MIPS_CP0_ERROREPC:
+		*v = (long)read_gc0_errorepc();
+		break;
+	case KVM_REG_MIPS_CP0_KSCRATCH1 ... KVM_REG_MIPS_CP0_KSCRATCH6:
+		idx = reg->id - KVM_REG_MIPS_CP0_KSCRATCH1 + 2;
+		if (!cpu_guest_has_kscr(idx))
+			return -EINVAL;
+		switch (idx) {
+		case 2:
+			*v = (long)read_gc0_kscratch1();
+			break;
+		case 3:
+			*v = (long)read_gc0_kscratch2();
+			break;
+		case 4:
+			*v = (long)read_gc0_kscratch3();
+			break;
+		case 5:
+			*v = (long)read_gc0_kscratch4();
+			break;
+		case 6:
+			*v = (long)read_gc0_kscratch5();
+			break;
+		case 7:
+			*v = (long)read_gc0_kscratch6();
+			break;
+		}
+		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;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int kvm_vz_set_one_reg(struct kvm_vcpu *vcpu,
+			      const struct kvm_one_reg *reg,
+			      s64 v)
+{
+	struct mips_coproc *cop0 = vcpu->arch.cop0;
+	unsigned int idx;
+	int ret = 0;
+	unsigned int cur, change;
+
+	switch (reg->id) {
+	case KVM_REG_MIPS_CP0_INDEX:
+		write_gc0_index(v);
+		break;
+	case KVM_REG_MIPS_CP0_ENTRYLO0:
+		write_gc0_entrylo0(entrylo_user_to_kvm(v));
+		break;
+	case KVM_REG_MIPS_CP0_ENTRYLO1:
+		write_gc0_entrylo1(entrylo_user_to_kvm(v));
+		break;
+	case KVM_REG_MIPS_CP0_CONTEXT:
+		write_gc0_context(v);
+		break;
+	case KVM_REG_MIPS_CP0_USERLOCAL:
+		if (!cpu_guest_has_userlocal)
+			return -EINVAL;
+		write_gc0_userlocal(v);
+		break;
+	case KVM_REG_MIPS_CP0_PAGEMASK:
+		write_gc0_pagemask(v);
+		break;
+	case KVM_REG_MIPS_CP0_PAGEGRAIN:
+		write_gc0_pagegrain(v);
+		break;
+	case KVM_REG_MIPS_CP0_WIRED:
+		change_gc0_wired(MIPSR6_WIRED_WIRED, v);
+		break;
+	case KVM_REG_MIPS_CP0_HWRENA:
+		write_gc0_hwrena(v);
+		break;
+	case KVM_REG_MIPS_CP0_BADVADDR:
+		write_gc0_badvaddr(v);
+		break;
+	case KVM_REG_MIPS_CP0_COUNT:
+		kvm_mips_write_count(vcpu, v);
+		break;
+	case KVM_REG_MIPS_CP0_ENTRYHI:
+		write_gc0_entryhi(v);
+		break;
+	case KVM_REG_MIPS_CP0_COMPARE:
+		kvm_mips_write_compare(vcpu, v, false);
+		break;
+	case KVM_REG_MIPS_CP0_STATUS:
+		write_gc0_status(v);
+		break;
+	case KVM_REG_MIPS_CP0_INTCTL:
+		write_gc0_intctl(v);
+		break;
+	case KVM_REG_MIPS_CP0_CAUSE:
+		/*
+		 * If the timer is stopped or started (DC bit) it must look
+		 * atomic with changes to the timer interrupt pending bit (TI).
+		 * A timer interrupt should not happen in between.
+		 */
+		if ((read_gc0_cause() ^ v) & CAUSEF_DC) {
+			if (v & CAUSEF_DC) {
+				/* disable timer first */
+				kvm_mips_count_disable_cause(vcpu);
+				change_gc0_cause((u32)~CAUSEF_DC, v);
+			} else {
+				/* enable timer last */
+				change_gc0_cause((u32)~CAUSEF_DC, v);
+				kvm_mips_count_enable_cause(vcpu);
+			}
+		} else {
+			write_gc0_cause(v);
+		}
+		break;
+	case KVM_REG_MIPS_CP0_EPC:
+		write_gc0_epc(v);
+		break;
+	case KVM_REG_MIPS_CP0_PRID:
+		kvm_write_c0_guest_prid(cop0, v);
+		break;
+	case KVM_REG_MIPS_CP0_EBASE:
+		kvm_vz_write_gc0_ebase(v);
+		break;
+	case KVM_REG_MIPS_CP0_CONFIG:
+		cur = read_gc0_config();
+		change = (cur ^ v) & kvm_vz_config_user_wrmask(vcpu);
+		if (change) {
+			v = cur ^ change;
+			write_gc0_config(v);
+		}
+		break;
+	case KVM_REG_MIPS_CP0_CONFIG1:
+		if (!cpu_guest_has_conf1)
+			break;
+		cur = read_gc0_config1();
+		change = (cur ^ v) & kvm_vz_config1_user_wrmask(vcpu);
+		if (change) {
+			v = cur ^ change;
+			write_gc0_config1(v);
+		}
+		break;
+	case KVM_REG_MIPS_CP0_CONFIG2:
+		if (!cpu_guest_has_conf2)
+			break;
+		cur = read_gc0_config2();
+		change = (cur ^ v) & kvm_vz_config2_user_wrmask(vcpu);
+		if (change) {
+			v = cur ^ change;
+			write_gc0_config2(v);
+		}
+		break;
+	case KVM_REG_MIPS_CP0_CONFIG3:
+		if (!cpu_guest_has_conf3)
+			break;
+		cur = read_gc0_config3();
+		change = (cur ^ v) & kvm_vz_config3_user_wrmask(vcpu);
+		if (change) {
+			v = cur ^ change;
+			write_gc0_config3(v);
+		}
+		break;
+	case KVM_REG_MIPS_CP0_CONFIG4:
+		if (!cpu_guest_has_conf4)
+			break;
+		cur = read_gc0_config4();
+		change = (cur ^ v) & kvm_vz_config4_user_wrmask(vcpu);
+		if (change) {
+			v = cur ^ change;
+			write_gc0_config4(v);
+		}
+		break;
+	case KVM_REG_MIPS_CP0_CONFIG5:
+		if (!cpu_guest_has_conf5)
+			break;
+		cur = read_gc0_config5();
+		change = (cur ^ v) & kvm_vz_config5_user_wrmask(vcpu);
+		if (change) {
+			v = cur ^ change;
+			write_gc0_config5(v);
+		}
+		break;
+#ifdef CONFIG_64BIT
+	case KVM_REG_MIPS_CP0_XCONTEXT:
+		write_gc0_xcontext(v);
+		break;
+#endif
+	case KVM_REG_MIPS_CP0_ERROREPC:
+		write_gc0_errorepc(v);
+		break;
+	case KVM_REG_MIPS_CP0_KSCRATCH1 ... KVM_REG_MIPS_CP0_KSCRATCH6:
+		idx = reg->id - KVM_REG_MIPS_CP0_KSCRATCH1 + 2;
+		if (!cpu_guest_has_kscr(idx))
+			return -EINVAL;
+		switch (idx) {
+		case 2:
+			write_gc0_kscratch1(v);
+			break;
+		case 3:
+			write_gc0_kscratch2(v);
+			break;
+		case 4:
+			write_gc0_kscratch3(v);
+			break;
+		case 5:
+			write_gc0_kscratch4(v);
+			break;
+		case 6:
+			write_gc0_kscratch5(v);
+			break;
+		case 7:
+			write_gc0_kscratch6(v);
+			break;
+		}
+		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;
+	default:
+		return -EINVAL;
+	}
+	return ret;
+}
+
+#define guestid_cache(cpu)	(cpu_data[cpu].guestid_cache)
+static void kvm_vz_get_new_guestid(unsigned long cpu, struct kvm_vcpu *vcpu)
+{
+	unsigned long guestid = guestid_cache(cpu);
+
+	if (!(++guestid & GUESTID_MASK)) {
+		if (cpu_has_vtag_icache)
+			flush_icache_all();
+
+		if (!guestid)		/* fix version if needed */
+			guestid = GUESTID_FIRST_VERSION;
+
+		++guestid;		/* guestid 0 reserved for root */
+
+		/* start new guestid cycle */
+		kvm_vz_local_flush_roottlb_all_guests();
+		kvm_vz_local_flush_guesttlb_all();
+	}
+
+	guestid_cache(cpu) = guestid;
+}
+
+/* Returns 1 if the guest TLB may be clobbered */
+static int kvm_vz_check_requests(struct kvm_vcpu *vcpu, int cpu)
+{
+	int ret = 0;
+	int i;
+
+	if (!vcpu->requests)
+		return 0;
+
+	if (kvm_check_request(KVM_REQ_TLB_FLUSH, vcpu)) {
+		if (cpu_has_guestid) {
+			/* Drop all GuestIDs for this VCPU */
+			for_each_possible_cpu(i)
+				vcpu->arch.vzguestid[i] = 0;
+			/* This will clobber guest TLB contents too */
+			ret = 1;
+		}
+		/*
+		 * For Root ASID Dealias (RAD) we don't do anything here, but we
+		 * still need the request to ensure we recheck asid_flush_mask.
+		 * We can still return 0 as only the root TLB will be affected
+		 * by a root ASID flush.
+		 */
+	}
+
+	return ret;
+}
+
+static void kvm_vz_vcpu_save_wired(struct kvm_vcpu *vcpu)
+{
+	unsigned int wired = read_gc0_wired();
+	struct kvm_mips_tlb *tlbs;
+	int i;
+
+	/* Expand the wired TLB array if necessary */
+	wired &= MIPSR6_WIRED_WIRED;
+	if (wired > vcpu->arch.wired_tlb_limit) {
+		tlbs = krealloc(vcpu->arch.wired_tlb, wired *
+				sizeof(*vcpu->arch.wired_tlb), GFP_ATOMIC);
+		if (WARN_ON(!tlbs)) {
+			/* Save whatever we can */
+			wired = vcpu->arch.wired_tlb_limit;
+		} else {
+			vcpu->arch.wired_tlb = tlbs;
+			vcpu->arch.wired_tlb_limit = wired;
+		}
+	}
+
+	if (wired)
+		/* Save wired entries from the guest TLB */
+		kvm_vz_save_guesttlb(vcpu->arch.wired_tlb, 0, wired);
+	/* Invalidate any dropped entries since last time */
+	for (i = wired; i < vcpu->arch.wired_tlb_used; ++i) {
+		vcpu->arch.wired_tlb[i].tlb_hi = UNIQUE_GUEST_ENTRYHI(i);
+		vcpu->arch.wired_tlb[i].tlb_lo[0] = 0;
+		vcpu->arch.wired_tlb[i].tlb_lo[1] = 0;
+		vcpu->arch.wired_tlb[i].tlb_mask = 0;
+	}
+	vcpu->arch.wired_tlb_used = wired;
+}
+
+static void kvm_vz_vcpu_load_wired(struct kvm_vcpu *vcpu)
+{
+	/* Load wired entries into the guest TLB */
+	if (vcpu->arch.wired_tlb)
+		kvm_vz_load_guesttlb(vcpu->arch.wired_tlb, 0,
+				     vcpu->arch.wired_tlb_used);
+}
+
+static void kvm_vz_vcpu_load_tlb(struct kvm_vcpu *vcpu, int cpu)
+{
+	struct kvm *kvm = vcpu->kvm;
+	struct mm_struct *gpa_mm = &kvm->arch.gpa_mm;
+	bool migrated;
+
+	/*
+	 * Are we entering guest context on a different CPU to last time?
+	 * If so, the VCPU's guest TLB state on this CPU may be stale.
+	 */
+	migrated = (vcpu->arch.last_exec_cpu != cpu);
+	vcpu->arch.last_exec_cpu = cpu;
+
+	/*
+	 * A vcpu's GuestID is set in GuestCtl1.ID when the vcpu is loaded and
+	 * remains set until another vcpu is loaded in.  As a rule GuestRID
+	 * remains zeroed when in root context unless the kernel is busy
+	 * manipulating guest tlb entries.
+	 */
+	if (cpu_has_guestid) {
+		/*
+		 * Check if our GuestID is of an older version and thus invalid.
+		 *
+		 * We also discard the stored GuestID if we've executed on
+		 * another CPU, as the guest mappings may have changed without
+		 * hypervisor knowledge.
+		 */
+		if (migrated ||
+		    (vcpu->arch.vzguestid[cpu] ^ guestid_cache(cpu)) &
+					GUESTID_VERSION_MASK) {
+			kvm_vz_get_new_guestid(cpu, vcpu);
+			vcpu->arch.vzguestid[cpu] = guestid_cache(cpu);
+			trace_kvm_guestid_change(vcpu,
+						 vcpu->arch.vzguestid[cpu]);
+		}
+
+		/* Restore GuestID */
+		change_c0_guestctl1(GUESTID_MASK, vcpu->arch.vzguestid[cpu]);
+	} else {
+		/*
+		 * The Guest TLB only stores a single guest's TLB state, so
+		 * flush it if another VCPU has executed on this CPU.
+		 *
+		 * We also flush if we've executed on another CPU, as the guest
+		 * mappings may have changed without hypervisor knowledge.
+		 */
+		if (migrated || last_exec_vcpu[cpu] != vcpu)
+			kvm_vz_local_flush_guesttlb_all();
+		last_exec_vcpu[cpu] = vcpu;
+
+		/*
+		 * Root ASID dealiases guest GPA mappings in the root TLB.
+		 * Allocate new root ASID if needed.
+		 */
+		if (cpumask_test_and_clear_cpu(cpu, &kvm->arch.asid_flush_mask)
+		    || (cpu_context(cpu, gpa_mm) ^ asid_cache(cpu)) &
+						asid_version_mask(cpu))
+			get_new_mmu_context(gpa_mm, cpu);
+	}
+}
+
+static int kvm_vz_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
+{
+	struct mips_coproc *cop0 = vcpu->arch.cop0;
+	bool migrated, all;
+
+	/*
+	 * Have we migrated to a different CPU?
+	 * If so, any old guest TLB state may be stale.
+	 */
+	migrated = (vcpu->arch.last_sched_cpu != cpu);
+
+	/*
+	 * Was this the last VCPU to run on this CPU?
+	 * If not, any old guest state from this VCPU will have been clobbered.
+	 */
+	all = migrated || (last_vcpu[cpu] != vcpu);
+	last_vcpu[cpu] = vcpu;
+
+	/*
+	 * Restore CP0_Wired unconditionally as we clear it after use, and
+	 * restore wired guest TLB entries (while in guest context).
+	 */
+	kvm_restore_gc0_wired(cop0);
+	if (current->flags & PF_VCPU) {
+		tlbw_use_hazard();
+		kvm_vz_vcpu_load_tlb(vcpu, cpu);
+		kvm_vz_vcpu_load_wired(vcpu);
+	}
+
+	/*
+	 * Restore timer state regardless, as e.g. Cause.TI can change over time
+	 * if left unmaintained.
+	 */
+	kvm_vz_restore_timer(vcpu);
+
+	/* Don't bother restoring registers multiple times unless necessary */
+	if (!all)
+		return 0;
+
+	/*
+	 * Restore config registers first, as some implementations restrict
+	 * writes to other registers when the corresponding feature bits aren't
+	 * set. For example Status.CU1 cannot be set unless Config1.FP is set.
+	 */
+	kvm_restore_gc0_config(cop0);
+	if (cpu_guest_has_conf1)
+		kvm_restore_gc0_config1(cop0);
+	if (cpu_guest_has_conf2)
+		kvm_restore_gc0_config2(cop0);
+	if (cpu_guest_has_conf3)
+		kvm_restore_gc0_config3(cop0);
+	if (cpu_guest_has_conf4)
+		kvm_restore_gc0_config4(cop0);
+	if (cpu_guest_has_conf5)
+		kvm_restore_gc0_config5(cop0);
+	if (cpu_guest_has_conf6)
+		kvm_restore_gc0_config6(cop0);
+	if (cpu_guest_has_conf7)
+		kvm_restore_gc0_config7(cop0);
+
+	kvm_restore_gc0_index(cop0);
+	kvm_restore_gc0_entrylo0(cop0);
+	kvm_restore_gc0_entrylo1(cop0);
+	kvm_restore_gc0_context(cop0);
+#ifdef CONFIG_64BIT
+	kvm_restore_gc0_xcontext(cop0);
+#endif
+	kvm_restore_gc0_pagemask(cop0);
+	kvm_restore_gc0_pagegrain(cop0);
+	kvm_restore_gc0_hwrena(cop0);
+	kvm_restore_gc0_badvaddr(cop0);
+	kvm_restore_gc0_entryhi(cop0);
+	kvm_restore_gc0_status(cop0);
+	kvm_restore_gc0_intctl(cop0);
+	kvm_restore_gc0_epc(cop0);
+	kvm_vz_write_gc0_ebase(kvm_read_sw_gc0_ebase(cop0));
+	if (cpu_guest_has_userlocal)
+		kvm_restore_gc0_userlocal(cop0);
+
+	kvm_restore_gc0_errorepc(cop0);
+
+	/* restore KScratch registers if enabled in guest */
+	if (cpu_guest_has_conf4) {
+		if (cpu_guest_has_kscr(2))
+			kvm_restore_gc0_kscratch1(cop0);
+		if (cpu_guest_has_kscr(3))
+			kvm_restore_gc0_kscratch2(cop0);
+		if (cpu_guest_has_kscr(4))
+			kvm_restore_gc0_kscratch3(cop0);
+		if (cpu_guest_has_kscr(5))
+			kvm_restore_gc0_kscratch4(cop0);
+		if (cpu_guest_has_kscr(6))
+			kvm_restore_gc0_kscratch5(cop0);
+		if (cpu_guest_has_kscr(7))
+			kvm_restore_gc0_kscratch6(cop0);
+	}
+
+	/* restore Root.GuestCtl2 from unused Guest guestctl2 register */
+	if (cpu_has_guestctl2)
+		write_c0_guestctl2(
+			cop0->reg[MIPS_CP0_GUESTCTL2][MIPS_CP0_GUESTCTL2_SEL]);
+
+	return 0;
+}
+
+static int kvm_vz_vcpu_put(struct kvm_vcpu *vcpu, int cpu)
+{
+	struct mips_coproc *cop0 = vcpu->arch.cop0;
+
+	if (current->flags & PF_VCPU)
+		kvm_vz_vcpu_save_wired(vcpu);
+
+	kvm_lose_fpu(vcpu);
+
+	kvm_save_gc0_index(cop0);
+	kvm_save_gc0_entrylo0(cop0);
+	kvm_save_gc0_entrylo1(cop0);
+	kvm_save_gc0_context(cop0);
+#ifdef CONFIG_64BIT
+	kvm_save_gc0_xcontext(cop0);
+#endif
+	kvm_save_gc0_pagemask(cop0);
+	kvm_save_gc0_pagegrain(cop0);
+	kvm_save_gc0_wired(cop0);
+	/* allow wired TLB entries to be overwritten */
+	clear_gc0_wired(MIPSR6_WIRED_WIRED);
+	kvm_save_gc0_hwrena(cop0);
+	kvm_save_gc0_badvaddr(cop0);
+	kvm_save_gc0_entryhi(cop0);
+	kvm_save_gc0_status(cop0);
+	kvm_save_gc0_intctl(cop0);
+	kvm_save_gc0_epc(cop0);
+	kvm_write_sw_gc0_ebase(cop0, kvm_vz_read_gc0_ebase());
+	if (cpu_guest_has_userlocal)
+		kvm_save_gc0_userlocal(cop0);
+
+	/* only save implemented config registers */
+	kvm_save_gc0_config(cop0);
+	if (cpu_guest_has_conf1)
+		kvm_save_gc0_config1(cop0);
+	if (cpu_guest_has_conf2)
+		kvm_save_gc0_config2(cop0);
+	if (cpu_guest_has_conf3)
+		kvm_save_gc0_config3(cop0);
+	if (cpu_guest_has_conf4)
+		kvm_save_gc0_config4(cop0);
+	if (cpu_guest_has_conf5)
+		kvm_save_gc0_config5(cop0);
+	if (cpu_guest_has_conf6)
+		kvm_save_gc0_config6(cop0);
+	if (cpu_guest_has_conf7)
+		kvm_save_gc0_config7(cop0);
+
+	kvm_save_gc0_errorepc(cop0);
+
+	/* save KScratch registers if enabled in guest */
+	if (cpu_guest_has_conf4) {
+		if (cpu_guest_has_kscr(2))
+			kvm_save_gc0_kscratch1(cop0);
+		if (cpu_guest_has_kscr(3))
+			kvm_save_gc0_kscratch2(cop0);
+		if (cpu_guest_has_kscr(4))
+			kvm_save_gc0_kscratch3(cop0);
+		if (cpu_guest_has_kscr(5))
+			kvm_save_gc0_kscratch4(cop0);
+		if (cpu_guest_has_kscr(6))
+			kvm_save_gc0_kscratch5(cop0);
+		if (cpu_guest_has_kscr(7))
+			kvm_save_gc0_kscratch6(cop0);
+	}
+
+	kvm_vz_save_timer(vcpu);
+
+	/* save Root.GuestCtl2 in unused Guest guestctl2 register */
+	if (cpu_has_guestctl2)
+		cop0->reg[MIPS_CP0_GUESTCTL2][MIPS_CP0_GUESTCTL2_SEL] =
+			read_c0_guestctl2();
+
+	return 0;
+}
+
+/**
+ * kvm_vz_resize_guest_vtlb() - Attempt to resize guest VTLB.
+ * @size:	Number of guest VTLB entries (0 < @size <= root VTLB entries).
+ *
+ * Attempt to resize the guest VTLB by writing guest Config registers. This is
+ * necessary for cores with a shared root/guest TLB to avoid overlap with wired
+ * entries in the root VTLB.
+ *
+ * Returns:	The resulting guest VTLB size.
+ */
+static unsigned int kvm_vz_resize_guest_vtlb(unsigned int size)
+{
+	unsigned int config4 = 0, ret = 0, limit;
+
+	/* Write MMUSize - 1 into guest Config registers */
+	if (cpu_guest_has_conf1)
+		change_gc0_config1(MIPS_CONF1_TLBS,
+				   (size - 1) << MIPS_CONF1_TLBS_SHIFT);
+	if (cpu_guest_has_conf4) {
+		config4 = read_gc0_config4();
+		if (cpu_has_mips_r6 || (config4 & MIPS_CONF4_MMUEXTDEF) ==
+		    MIPS_CONF4_MMUEXTDEF_VTLBSIZEEXT) {
+			config4 &= ~MIPS_CONF4_VTLBSIZEEXT;
+			config4 |= ((size - 1) >> MIPS_CONF1_TLBS_SIZE) <<
+				MIPS_CONF4_VTLBSIZEEXT_SHIFT;
+		} else if ((config4 & MIPS_CONF4_MMUEXTDEF) ==
+			   MIPS_CONF4_MMUEXTDEF_MMUSIZEEXT) {
+			config4 &= ~MIPS_CONF4_MMUSIZEEXT;
+			config4 |= ((size - 1) >> MIPS_CONF1_TLBS_SIZE) <<
+				MIPS_CONF4_MMUSIZEEXT_SHIFT;
+		}
+		write_gc0_config4(config4);
+	}
+
+	/*
+	 * Set Guest.Wired.Limit = 0 (no limit up to Guest.MMUSize-1), unless it
+	 * would exceed Root.Wired.Limit (clearing Guest.Wired.Wired so write
+	 * not dropped)
+	 */
+	if (cpu_has_mips_r6) {
+		limit = (read_c0_wired() & MIPSR6_WIRED_LIMIT) >>
+						MIPSR6_WIRED_LIMIT_SHIFT;
+		if (size - 1 <= limit)
+			limit = 0;
+		write_gc0_wired(limit << MIPSR6_WIRED_LIMIT_SHIFT);
+	}
+
+	/* Read back MMUSize - 1 */
+	back_to_back_c0_hazard();
+	if (cpu_guest_has_conf1)
+		ret = (read_gc0_config1() & MIPS_CONF1_TLBS) >>
+						MIPS_CONF1_TLBS_SHIFT;
+	if (config4) {
+		if (cpu_has_mips_r6 || (config4 & MIPS_CONF4_MMUEXTDEF) ==
+		    MIPS_CONF4_MMUEXTDEF_VTLBSIZEEXT)
+			ret |= ((config4 & MIPS_CONF4_VTLBSIZEEXT) >>
+				MIPS_CONF4_VTLBSIZEEXT_SHIFT) <<
+				MIPS_CONF1_TLBS_SIZE;
+		else if ((config4 & MIPS_CONF4_MMUEXTDEF) ==
+			 MIPS_CONF4_MMUEXTDEF_MMUSIZEEXT)
+			ret |= ((config4 & MIPS_CONF4_MMUSIZEEXT) >>
+				MIPS_CONF4_MMUSIZEEXT_SHIFT) <<
+				MIPS_CONF1_TLBS_SIZE;
+	}
+	return ret + 1;
+}
+
+static int kvm_vz_hardware_enable(void)
+{
+	unsigned int mmu_size, guest_mmu_size, ftlb_size;
+
+	/*
+	 * ImgTec cores tend to use a shared root/guest TLB. To avoid overlap of
+	 * root wired and guest entries, the guest TLB may need resizing.
+	 */
+	mmu_size = current_cpu_data.tlbsizevtlb;
+	ftlb_size = current_cpu_data.tlbsize - mmu_size;
+
+	/* Try switching to maximum guest VTLB size for flush */
+	guest_mmu_size = kvm_vz_resize_guest_vtlb(mmu_size);
+	current_cpu_data.guest.tlbsize = guest_mmu_size + ftlb_size;
+	kvm_vz_local_flush_guesttlb_all();
+
+	/*
+	 * Reduce to make space for root wired entries and at least 2 root
+	 * non-wired entries. This does assume that long-term wired entries
+	 * won't be added later.
+	 */
+	guest_mmu_size = mmu_size - num_wired_entries() - 2;
+	guest_mmu_size = kvm_vz_resize_guest_vtlb(guest_mmu_size);
+	current_cpu_data.guest.tlbsize = guest_mmu_size + ftlb_size;
+
+	/*
+	 * Write the VTLB size, but if another CPU has already written, check it
+	 * matches or we won't provide a consistent view to the guest. If this
+	 * ever happens it suggests an asymmetric number of wired entries.
+	 */
+	if (cmpxchg(&kvm_vz_guest_vtlb_size, 0, guest_mmu_size) &&
+	    WARN(guest_mmu_size != kvm_vz_guest_vtlb_size,
+		 "Available guest VTLB size mismatch"))
+		return -EINVAL;
+
+	/*
+	 * Enable virtualization features granting guest direct control of
+	 * certain features:
+	 * CP0=1:	Guest coprocessor 0 context.
+	 * AT=Guest:	Guest MMU.
+	 * CG=1:	Hit (virtual address) CACHE operations (optional).
+	 * CF=1:	Guest Config registers.
+	 * CGI=1:	Indexed flush CACHE operations (optional).
+	 */
+	write_c0_guestctl0(MIPS_GCTL0_CP0 |
+			   (MIPS_GCTL0_AT_GUEST << MIPS_GCTL0_AT_SHIFT) |
+			   MIPS_GCTL0_CG | MIPS_GCTL0_CF);
+	if (cpu_has_guestctl0ext)
+		set_c0_guestctl0ext(MIPS_GCTL0EXT_CGI);
+
+	if (cpu_has_guestid) {
+		write_c0_guestctl1(0);
+		kvm_vz_local_flush_roottlb_all_guests();
+
+		GUESTID_MASK = current_cpu_data.guestid_mask;
+		GUESTID_FIRST_VERSION = GUESTID_MASK + 1;
+		GUESTID_VERSION_MASK = ~GUESTID_MASK;
+
+		current_cpu_data.guestid_cache = GUESTID_FIRST_VERSION;
+	}
+
+	/* clear any pending injected virtual guest interrupts */
+	if (cpu_has_guestctl2)
+		clear_c0_guestctl2(0x3f << 10);
+
+	return 0;
+}
+
+static void kvm_vz_hardware_disable(void)
+{
+	kvm_vz_local_flush_guesttlb_all();
+
+	if (cpu_has_guestid) {
+		write_c0_guestctl1(0);
+		kvm_vz_local_flush_roottlb_all_guests();
+	}
+}
+
+static int kvm_vz_check_extension(struct kvm *kvm, long ext)
+{
+	int r;
+
+	switch (ext) {
+	case KVM_CAP_MIPS_VZ:
+		/* we wouldn't be here unless cpu_has_vz */
+		r = 1;
+		break;
+#ifdef CONFIG_64BIT
+	case KVM_CAP_MIPS_64BIT:
+		/* We support 64-bit registers/operations and addresses */
+		r = 2;
+		break;
+#endif
+	default:
+		r = 0;
+		break;
+	}
+
+	return r;
+}
+
+static int kvm_vz_vcpu_init(struct kvm_vcpu *vcpu)
+{
+	int i;
+
+	for_each_possible_cpu(i)
+		vcpu->arch.vzguestid[i] = 0;
+
+	return 0;
+}
+
+static void kvm_vz_vcpu_uninit(struct kvm_vcpu *vcpu)
+{
+	int cpu;
+
+	/*
+	 * If the VCPU is freed and reused as another VCPU, we don't want the
+	 * matching pointer wrongly hanging around in last_vcpu[] or
+	 * last_exec_vcpu[].
+	 */
+	for_each_possible_cpu(cpu) {
+		if (last_vcpu[cpu] == vcpu)
+			last_vcpu[cpu] = NULL;
+		if (last_exec_vcpu[cpu] == vcpu)
+			last_exec_vcpu[cpu] = NULL;
+	}
+}
+
+static int kvm_vz_vcpu_setup(struct kvm_vcpu *vcpu)
+{
+	struct mips_coproc *cop0 = vcpu->arch.cop0;
+	unsigned long count_hz = 100*1000*1000; /* default to 100 MHz */
+
+	/*
+	 * Start off the timer at the same frequency as the host timer, but the
+	 * soft timer doesn't handle frequencies greater than 1GHz yet.
+	 */
+	if (mips_hpt_frequency && mips_hpt_frequency <= NSEC_PER_SEC)
+		count_hz = mips_hpt_frequency;
+	kvm_mips_init_count(vcpu, count_hz);
+
+	/*
+	 * Initialize guest register state to valid architectural reset state.
+	 */
+
+	/* PageGrain */
+	if (cpu_has_mips_r6)
+		kvm_write_sw_gc0_pagegrain(cop0, PG_RIE | PG_XIE | PG_IEC);
+	/* Wired */
+	if (cpu_has_mips_r6)
+		kvm_write_sw_gc0_wired(cop0,
+				       read_gc0_wired() & MIPSR6_WIRED_LIMIT);
+	/* Status */
+	kvm_write_sw_gc0_status(cop0, ST0_BEV | ST0_ERL);
+	if (cpu_has_mips_r6)
+		kvm_change_sw_gc0_status(cop0, ST0_FR, read_gc0_status());
+	/* IntCtl */
+	kvm_write_sw_gc0_intctl(cop0, read_gc0_intctl() &
+				(INTCTLF_IPFDC | INTCTLF_IPPCI | INTCTLF_IPTI));
+	/* PRId */
+	kvm_write_sw_gc0_prid(cop0, boot_cpu_data.processor_id);
+	/* EBase */
+	kvm_write_sw_gc0_ebase(cop0, (s32)0x80000000 | vcpu->vcpu_id);
+	/* Config */
+	kvm_save_gc0_config(cop0);
+	/* architecturally writable (e.g. from guest) */
+	kvm_change_sw_gc0_config(cop0, CONF_CM_CMASK,
+				 _page_cachable_default >> _CACHE_SHIFT);
+	/* architecturally read only, but maybe writable from root */
+	kvm_change_sw_gc0_config(cop0, MIPS_CONF_MT, read_c0_config());
+	if (cpu_guest_has_conf1) {
+		kvm_set_sw_gc0_config(cop0, MIPS_CONF_M);
+		/* Config1 */
+		kvm_save_gc0_config1(cop0);
+		/* architecturally read only, but maybe writable from root */
+		kvm_clear_sw_gc0_config1(cop0, MIPS_CONF1_C2	|
+					       MIPS_CONF1_MD	|
+					       MIPS_CONF1_PC	|
+					       MIPS_CONF1_WR	|
+					       MIPS_CONF1_CA	|
+					       MIPS_CONF1_FP);
+	}
+	if (cpu_guest_has_conf2) {
+		kvm_set_sw_gc0_config1(cop0, MIPS_CONF_M);
+		/* Config2 */
+		kvm_save_gc0_config2(cop0);
+	}
+	if (cpu_guest_has_conf3) {
+		kvm_set_sw_gc0_config2(cop0, MIPS_CONF_M);
+		/* Config3 */
+		kvm_save_gc0_config3(cop0);
+		/* architecturally writable (e.g. from guest) */
+		kvm_clear_sw_gc0_config3(cop0, MIPS_CONF3_ISA_OE);
+		/* architecturally read only, but maybe writable from root */
+		kvm_clear_sw_gc0_config3(cop0, MIPS_CONF3_MSA	|
+					       MIPS_CONF3_BPG	|
+					       MIPS_CONF3_ULRI	|
+					       MIPS_CONF3_DSP	|
+					       MIPS_CONF3_CTXTC	|
+					       MIPS_CONF3_ITL	|
+					       MIPS_CONF3_LPA	|
+					       MIPS_CONF3_VEIC	|
+					       MIPS_CONF3_VINT	|
+					       MIPS_CONF3_SP	|
+					       MIPS_CONF3_CDMM	|
+					       MIPS_CONF3_MT	|
+					       MIPS_CONF3_SM	|
+					       MIPS_CONF3_TL);
+	}
+	if (cpu_guest_has_conf4) {
+		kvm_set_sw_gc0_config3(cop0, MIPS_CONF_M);
+		/* Config4 */
+		kvm_save_gc0_config4(cop0);
+	}
+	if (cpu_guest_has_conf5) {
+		kvm_set_sw_gc0_config4(cop0, MIPS_CONF_M);
+		/* Config5 */
+		kvm_save_gc0_config5(cop0);
+		/* architecturally writable (e.g. from guest) */
+		kvm_clear_sw_gc0_config5(cop0, MIPS_CONF5_K	|
+					       MIPS_CONF5_CV	|
+					       MIPS_CONF5_MSAEN	|
+					       MIPS_CONF5_UFE	|
+					       MIPS_CONF5_FRE	|
+					       MIPS_CONF5_SBRI	|
+					       MIPS_CONF5_UFR);
+		/* architecturally read only, but maybe writable from root */
+		kvm_clear_sw_gc0_config5(cop0, MIPS_CONF5_MRP);
+	}
+
+	/* start with no pending virtual guest interrupts */
+	if (cpu_has_guestctl2)
+		cop0->reg[MIPS_CP0_GUESTCTL2][MIPS_CP0_GUESTCTL2_SEL] = 0;
+
+	/* Put PC at reset vector */
+	vcpu->arch.pc = CKSEG1ADDR(0x1fc00000);
+
+	return 0;
+}
+
+static void kvm_vz_flush_shadow_all(struct kvm *kvm)
+{
+	if (cpu_has_guestid) {
+		/* Flush GuestID for each VCPU individually */
+		kvm_flush_remote_tlbs(kvm);
+	} else {
+		/*
+		 * For each CPU there is a single GPA ASID used by all VCPUs in
+		 * the VM, so it doesn't make sense for the VCPUs to handle
+		 * invalidation of these ASIDs individually.
+		 *
+		 * Instead mark all CPUs as needing ASID invalidation in
+		 * asid_flush_mask, and just use kvm_flush_remote_tlbs(kvm) to
+		 * kick any running VCPUs so they check asid_flush_mask.
+		 */
+		cpumask_setall(&kvm->arch.asid_flush_mask);
+		kvm_flush_remote_tlbs(kvm);
+	}
+}
+
+static void kvm_vz_flush_shadow_memslot(struct kvm *kvm,
+					const struct kvm_memory_slot *slot)
+{
+	kvm_vz_flush_shadow_all(kvm);
+}
+
+static void kvm_vz_vcpu_reenter(struct kvm_run *run, struct kvm_vcpu *vcpu)
+{
+	int cpu = smp_processor_id();
+	int preserve_guest_tlb;
+
+	preserve_guest_tlb = kvm_vz_check_requests(vcpu, cpu);
+
+	if (preserve_guest_tlb)
+		kvm_vz_vcpu_save_wired(vcpu);
+
+	kvm_vz_vcpu_load_tlb(vcpu, cpu);
+
+	if (preserve_guest_tlb)
+		kvm_vz_vcpu_load_wired(vcpu);
+}
+
+static int kvm_vz_vcpu_run(struct kvm_run *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, read_gc0_cause());
+
+	kvm_vz_check_requests(vcpu, cpu);
+	kvm_vz_vcpu_load_tlb(vcpu, cpu);
+	kvm_vz_vcpu_load_wired(vcpu);
+
+	r = vcpu->arch.vcpu_run(run, vcpu);
+
+	kvm_vz_vcpu_save_wired(vcpu);
+
+	return r;
+}
+
+static struct kvm_mips_callbacks kvm_vz_callbacks = {
+	.handle_cop_unusable = kvm_trap_vz_handle_cop_unusable,
+	.handle_tlb_mod = kvm_trap_vz_handle_tlb_st_miss,
+	.handle_tlb_ld_miss = kvm_trap_vz_handle_tlb_ld_miss,
+	.handle_tlb_st_miss = kvm_trap_vz_handle_tlb_st_miss,
+	.handle_addr_err_st = kvm_trap_vz_no_handler,
+	.handle_addr_err_ld = kvm_trap_vz_no_handler,
+	.handle_syscall = kvm_trap_vz_no_handler,
+	.handle_res_inst = kvm_trap_vz_no_handler,
+	.handle_break = kvm_trap_vz_no_handler,
+	.handle_msa_disabled = kvm_trap_vz_handle_msa_disabled,
+	.handle_guest_exit = kvm_trap_vz_handle_guest_exit,
+
+	.hardware_enable = kvm_vz_hardware_enable,
+	.hardware_disable = kvm_vz_hardware_disable,
+	.check_extension = kvm_vz_check_extension,
+	.vcpu_init = kvm_vz_vcpu_init,
+	.vcpu_uninit = kvm_vz_vcpu_uninit,
+	.vcpu_setup = kvm_vz_vcpu_setup,
+	.flush_shadow_all = kvm_vz_flush_shadow_all,
+	.flush_shadow_memslot = kvm_vz_flush_shadow_memslot,
+	.gva_to_gpa = kvm_vz_gva_to_gpa_cb,
+	.queue_timer_int = kvm_vz_queue_timer_int_cb,
+	.dequeue_timer_int = kvm_vz_dequeue_timer_int_cb,
+	.queue_io_int = kvm_vz_queue_io_int_cb,
+	.dequeue_io_int = kvm_vz_dequeue_io_int_cb,
+	.irq_deliver = kvm_vz_irq_deliver_cb,
+	.irq_clear = kvm_vz_irq_clear_cb,
+	.num_regs = kvm_vz_num_regs,
+	.copy_reg_indices = kvm_vz_copy_reg_indices,
+	.get_one_reg = kvm_vz_get_one_reg,
+	.set_one_reg = kvm_vz_set_one_reg,
+	.vcpu_load = kvm_vz_vcpu_load,
+	.vcpu_put = kvm_vz_vcpu_put,
+	.vcpu_run = kvm_vz_vcpu_run,
+	.vcpu_reenter = kvm_vz_vcpu_reenter,
+};
+
+int kvm_mips_emulation_init(struct kvm_mips_callbacks **install_callbacks)
+{
+	if (!cpu_has_vz)
+		return -ENODEV;
+
+	/*
+	 * VZ requires at least 2 KScratch registers, so it should have been
+	 * possible to allocate pgd_reg.
+	 */
+	if (WARN(pgd_reg == -1,
+		 "pgd_reg not allocated even though cpu_has_vz\n"))
+		return -ENODEV;
+
+	pr_info("Starting KVM with MIPS VZ extensions\n");
+
+	*install_callbacks = &kvm_vz_callbacks;
+	return 0;
+}