--- /dev/null
+/*
+ * 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;
+}