KVM/MIPS32: Routines to handle specific traps/exceptions while executing the guest.
authorSanjay Lal <sanjayl@kymasys.com>
Thu, 22 Nov 2012 02:34:09 +0000 (18:34 -0800)
committerRalf Baechle <ralf@linux-mips.org>
Wed, 8 May 2013 01:55:36 +0000 (03:55 +0200)
Signed-off-by: Sanjay Lal <sanjayl@kymasys.com>
Cc: kvm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
arch/mips/kvm/kvm_cb.c [new file with mode: 0644]
arch/mips/kvm/kvm_trap_emul.c [new file with mode: 0644]

diff --git a/arch/mips/kvm/kvm_cb.c b/arch/mips/kvm/kvm_cb.c
new file mode 100644 (file)
index 0000000..313c2e3
--- /dev/null
@@ -0,0 +1,14 @@
+/*
+ * 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.
+ *
+ * Copyright (C) 2012  MIPS Technologies, Inc.  All rights reserved.
+ * Authors: Yann Le Du <ledu@kymasys.com>
+ */
+
+#include <linux/export.h>
+#include <linux/kvm_host.h>
+
+struct kvm_mips_callbacks *kvm_mips_callbacks;
+EXPORT_SYMBOL(kvm_mips_callbacks);
diff --git a/arch/mips/kvm/kvm_trap_emul.c b/arch/mips/kvm/kvm_trap_emul.c
new file mode 100644 (file)
index 0000000..466aeef
--- /dev/null
@@ -0,0 +1,482 @@
+/*
+* This file is subject to the terms and conditions of the GNU General Public
+* License.  See the file "COPYING" in the main directory of this archive
+* for more details.
+*
+* KVM/MIPS: Deliver/Emulate exceptions to the guest kernel
+*
+* Copyright (C) 2012  MIPS Technologies, Inc.  All rights reserved.
+* Authors: Sanjay Lal <sanjayl@kymasys.com>
+*/
+
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/vmalloc.h>
+
+#include <linux/kvm_host.h>
+
+#include "kvm_mips_opcode.h"
+#include "kvm_mips_int.h"
+
+static gpa_t kvm_trap_emul_gva_to_gpa_cb(gva_t gva)
+{
+       gpa_t gpa;
+       uint32_t kseg = KSEGX(gva);
+
+       if ((kseg == CKSEG0) || (kseg == CKSEG1))
+               gpa = CPHYSADDR(gva);
+       else {
+               printk("%s: cannot find GPA for GVA: %#lx\n", __func__, gva);
+               kvm_mips_dump_host_tlbs();
+               gpa = KVM_INVALID_ADDR;
+       }
+
+#ifdef DEBUG
+       kvm_debug("%s: gva %#lx, gpa: %#llx\n", __func__, gva, gpa);
+#endif
+
+       return gpa;
+}
+
+
+static int kvm_trap_emul_handle_cop_unusable(struct kvm_vcpu *vcpu)
+{
+       struct kvm_run *run = vcpu->run;
+       uint32_t __user *opc = (uint32_t __user *) vcpu->arch.pc;
+       unsigned long cause = vcpu->arch.host_cp0_cause;
+       enum emulation_result er = EMULATE_DONE;
+       int ret = RESUME_GUEST;
+
+       if (((cause & CAUSEF_CE) >> CAUSEB_CE) == 1) {
+               er = kvm_mips_emulate_fpu_exc(cause, opc, run, vcpu);
+       } else
+               er = kvm_mips_emulate_inst(cause, opc, run, vcpu);
+
+       switch (er) {
+       case EMULATE_DONE:
+               ret = RESUME_GUEST;
+               break;
+
+       case EMULATE_FAIL:
+               run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+               ret = RESUME_HOST;
+               break;
+
+       case EMULATE_WAIT:
+               run->exit_reason = KVM_EXIT_INTR;
+               ret = RESUME_HOST;
+               break;
+
+       default:
+               BUG();
+       }
+       return ret;
+}
+
+static int kvm_trap_emul_handle_tlb_mod(struct kvm_vcpu *vcpu)
+{
+       struct kvm_run *run = vcpu->run;
+       uint32_t __user *opc = (uint32_t __user *) vcpu->arch.pc;
+       unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
+       unsigned long cause = vcpu->arch.host_cp0_cause;
+       enum emulation_result er = EMULATE_DONE;
+       int ret = RESUME_GUEST;
+
+       if (KVM_GUEST_KSEGX(badvaddr) < KVM_GUEST_KSEG0
+           || KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG23) {
+#ifdef DEBUG
+               kvm_debug
+                   ("USER/KSEG23 ADDR TLB MOD fault: cause %#lx, PC: %p, BadVaddr: %#lx\n",
+                    cause, opc, badvaddr);
+#endif
+               er = kvm_mips_handle_tlbmod(cause, opc, run, vcpu);
+
+               if (er == EMULATE_DONE)
+                       ret = RESUME_GUEST;
+               else {
+                       run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+                       ret = RESUME_HOST;
+               }
+       } else if (KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG0) {
+               /* XXXKYMA: The guest kernel does not expect to get this fault when we are not
+                * using HIGHMEM. Need to address this in a HIGHMEM kernel
+                */
+               printk
+                   ("TLB MOD fault not handled, cause %#lx, PC: %p, BadVaddr: %#lx\n",
+                    cause, opc, badvaddr);
+               kvm_mips_dump_host_tlbs();
+               kvm_arch_vcpu_dump_regs(vcpu);
+               run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+               ret = RESUME_HOST;
+       } else {
+               printk
+                   ("Illegal TLB Mod fault address , cause %#lx, PC: %p, BadVaddr: %#lx\n",
+                    cause, opc, badvaddr);
+               kvm_mips_dump_host_tlbs();
+               kvm_arch_vcpu_dump_regs(vcpu);
+               run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+               ret = RESUME_HOST;
+       }
+       return ret;
+}
+
+static int kvm_trap_emul_handle_tlb_st_miss(struct kvm_vcpu *vcpu)
+{
+       struct kvm_run *run = vcpu->run;
+       uint32_t __user *opc = (uint32_t __user *) vcpu->arch.pc;
+       unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
+       unsigned long cause = vcpu->arch.host_cp0_cause;
+       enum emulation_result er = EMULATE_DONE;
+       int ret = RESUME_GUEST;
+
+       if (((badvaddr & PAGE_MASK) == KVM_GUEST_COMMPAGE_ADDR)
+           && KVM_GUEST_KERNEL_MODE(vcpu)) {
+               if (kvm_mips_handle_commpage_tlb_fault(badvaddr, vcpu) < 0) {
+                       run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+                       ret = RESUME_HOST;
+               }
+       } else if (KVM_GUEST_KSEGX(badvaddr) < KVM_GUEST_KSEG0
+                  || KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG23) {
+#ifdef DEBUG
+               kvm_debug
+                   ("USER ADDR TLB LD fault: cause %#lx, PC: %p, BadVaddr: %#lx\n",
+                    cause, opc, badvaddr);
+#endif
+               er = kvm_mips_handle_tlbmiss(cause, opc, run, vcpu);
+               if (er == EMULATE_DONE)
+                       ret = RESUME_GUEST;
+               else {
+                       run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+                       ret = RESUME_HOST;
+               }
+       } else if (KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG0) {
+               /* All KSEG0 faults are handled by KVM, as the guest kernel does not
+                * expect to ever get them
+                */
+               if (kvm_mips_handle_kseg0_tlb_fault
+                   (vcpu->arch.host_cp0_badvaddr, vcpu) < 0) {
+                       run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+                       ret = RESUME_HOST;
+               }
+       } else {
+               kvm_err
+                   ("Illegal TLB LD fault address , cause %#lx, PC: %p, BadVaddr: %#lx\n",
+                    cause, opc, badvaddr);
+               kvm_mips_dump_host_tlbs();
+               kvm_arch_vcpu_dump_regs(vcpu);
+               run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+               ret = RESUME_HOST;
+       }
+       return ret;
+}
+
+static int kvm_trap_emul_handle_tlb_ld_miss(struct kvm_vcpu *vcpu)
+{
+       struct kvm_run *run = vcpu->run;
+       uint32_t __user *opc = (uint32_t __user *) vcpu->arch.pc;
+       unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
+       unsigned long cause = vcpu->arch.host_cp0_cause;
+       enum emulation_result er = EMULATE_DONE;
+       int ret = RESUME_GUEST;
+
+       if (((badvaddr & PAGE_MASK) == KVM_GUEST_COMMPAGE_ADDR)
+           && KVM_GUEST_KERNEL_MODE(vcpu)) {
+               if (kvm_mips_handle_commpage_tlb_fault(badvaddr, vcpu) < 0) {
+                       run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+                       ret = RESUME_HOST;
+               }
+       } else if (KVM_GUEST_KSEGX(badvaddr) < KVM_GUEST_KSEG0
+                  || KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG23) {
+#ifdef DEBUG
+               kvm_debug("USER ADDR TLB ST fault: PC: %#lx, BadVaddr: %#lx\n",
+                         vcpu->arch.pc, badvaddr);
+#endif
+
+               /* User Address (UA) fault, this could happen if
+                * (1) TLB entry not present/valid in both Guest and shadow host TLBs, in this
+                *     case we pass on the fault to the guest kernel and let it handle it.
+                * (2) TLB entry is present in the Guest TLB but not in the shadow, in this
+                *     case we inject the TLB from the Guest TLB into the shadow host TLB
+                */
+
+               er = kvm_mips_handle_tlbmiss(cause, opc, run, vcpu);
+               if (er == EMULATE_DONE)
+                       ret = RESUME_GUEST;
+               else {
+                       run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+                       ret = RESUME_HOST;
+               }
+       } else if (KVM_GUEST_KSEGX(badvaddr) == KVM_GUEST_KSEG0) {
+               if (kvm_mips_handle_kseg0_tlb_fault
+                   (vcpu->arch.host_cp0_badvaddr, vcpu) < 0) {
+                       run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+                       ret = RESUME_HOST;
+               }
+       } else {
+               printk
+                   ("Illegal TLB ST fault address , cause %#lx, PC: %p, BadVaddr: %#lx\n",
+                    cause, opc, badvaddr);
+               kvm_mips_dump_host_tlbs();
+               kvm_arch_vcpu_dump_regs(vcpu);
+               run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+               ret = RESUME_HOST;
+       }
+       return ret;
+}
+
+static int kvm_trap_emul_handle_addr_err_st(struct kvm_vcpu *vcpu)
+{
+       struct kvm_run *run = vcpu->run;
+       uint32_t __user *opc = (uint32_t __user *) vcpu->arch.pc;
+       unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
+       unsigned long cause = vcpu->arch.host_cp0_cause;
+       enum emulation_result er = EMULATE_DONE;
+       int ret = RESUME_GUEST;
+
+       if (KVM_GUEST_KERNEL_MODE(vcpu)
+           && (KSEGX(badvaddr) == CKSEG0 || KSEGX(badvaddr) == CKSEG1)) {
+#ifdef DEBUG
+               kvm_debug("Emulate Store to MMIO space\n");
+#endif
+               er = kvm_mips_emulate_inst(cause, opc, run, vcpu);
+               if (er == EMULATE_FAIL) {
+                       printk("Emulate Store to MMIO space failed\n");
+                       run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+                       ret = RESUME_HOST;
+               } else {
+                       run->exit_reason = KVM_EXIT_MMIO;
+                       ret = RESUME_HOST;
+               }
+       } else {
+               printk
+                   ("Address Error (STORE): cause %#lx, PC: %p, BadVaddr: %#lx\n",
+                    cause, opc, badvaddr);
+               run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+               ret = RESUME_HOST;
+       }
+       return ret;
+}
+
+static int kvm_trap_emul_handle_addr_err_ld(struct kvm_vcpu *vcpu)
+{
+       struct kvm_run *run = vcpu->run;
+       uint32_t __user *opc = (uint32_t __user *) vcpu->arch.pc;
+       unsigned long badvaddr = vcpu->arch.host_cp0_badvaddr;
+       unsigned long cause = vcpu->arch.host_cp0_cause;
+       enum emulation_result er = EMULATE_DONE;
+       int ret = RESUME_GUEST;
+
+       if (KSEGX(badvaddr) == CKSEG0 || KSEGX(badvaddr) == CKSEG1) {
+#ifdef DEBUG
+               kvm_debug("Emulate Load from MMIO space @ %#lx\n", badvaddr);
+#endif
+               er = kvm_mips_emulate_inst(cause, opc, run, vcpu);
+               if (er == EMULATE_FAIL) {
+                       printk("Emulate Load from MMIO space failed\n");
+                       run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+                       ret = RESUME_HOST;
+               } else {
+                       run->exit_reason = KVM_EXIT_MMIO;
+                       ret = RESUME_HOST;
+               }
+       } else {
+               printk
+                   ("Address Error (LOAD): cause %#lx, PC: %p, BadVaddr: %#lx\n",
+                    cause, opc, badvaddr);
+               run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+               ret = RESUME_HOST;
+               er = EMULATE_FAIL;
+       }
+       return ret;
+}
+
+static int kvm_trap_emul_handle_syscall(struct kvm_vcpu *vcpu)
+{
+       struct kvm_run *run = vcpu->run;
+       uint32_t __user *opc = (uint32_t __user *) vcpu->arch.pc;
+       unsigned long cause = vcpu->arch.host_cp0_cause;
+       enum emulation_result er = EMULATE_DONE;
+       int ret = RESUME_GUEST;
+
+       er = kvm_mips_emulate_syscall(cause, opc, run, vcpu);
+       if (er == EMULATE_DONE)
+               ret = RESUME_GUEST;
+       else {
+               run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+               ret = RESUME_HOST;
+       }
+       return ret;
+}
+
+static int kvm_trap_emul_handle_res_inst(struct kvm_vcpu *vcpu)
+{
+       struct kvm_run *run = vcpu->run;
+       uint32_t __user *opc = (uint32_t __user *) vcpu->arch.pc;
+       unsigned long cause = vcpu->arch.host_cp0_cause;
+       enum emulation_result er = EMULATE_DONE;
+       int ret = RESUME_GUEST;
+
+       er = kvm_mips_handle_ri(cause, opc, run, vcpu);
+       if (er == EMULATE_DONE)
+               ret = RESUME_GUEST;
+       else {
+               run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+               ret = RESUME_HOST;
+       }
+       return ret;
+}
+
+static int kvm_trap_emul_handle_break(struct kvm_vcpu *vcpu)
+{
+       struct kvm_run *run = vcpu->run;
+       uint32_t __user *opc = (uint32_t __user *) vcpu->arch.pc;
+       unsigned long cause = vcpu->arch.host_cp0_cause;
+       enum emulation_result er = EMULATE_DONE;
+       int ret = RESUME_GUEST;
+
+       er = kvm_mips_emulate_bp_exc(cause, opc, run, vcpu);
+       if (er == EMULATE_DONE)
+               ret = RESUME_GUEST;
+       else {
+               run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+               ret = RESUME_HOST;
+       }
+       return ret;
+}
+
+static int
+kvm_trap_emul_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
+{
+       struct mips_coproc *cop0 = vcpu->arch.cop0;
+
+       kvm_write_c0_guest_index(cop0, regs->cp0reg[MIPS_CP0_TLB_INDEX][0]);
+       kvm_write_c0_guest_context(cop0, regs->cp0reg[MIPS_CP0_TLB_CONTEXT][0]);
+       kvm_write_c0_guest_badvaddr(cop0, regs->cp0reg[MIPS_CP0_BAD_VADDR][0]);
+       kvm_write_c0_guest_entryhi(cop0, regs->cp0reg[MIPS_CP0_TLB_HI][0]);
+       kvm_write_c0_guest_epc(cop0, regs->cp0reg[MIPS_CP0_EXC_PC][0]);
+
+       kvm_write_c0_guest_status(cop0, regs->cp0reg[MIPS_CP0_STATUS][0]);
+       kvm_write_c0_guest_cause(cop0, regs->cp0reg[MIPS_CP0_CAUSE][0]);
+       kvm_write_c0_guest_pagemask(cop0,
+                                   regs->cp0reg[MIPS_CP0_TLB_PG_MASK][0]);
+       kvm_write_c0_guest_wired(cop0, regs->cp0reg[MIPS_CP0_TLB_WIRED][0]);
+       kvm_write_c0_guest_errorepc(cop0, regs->cp0reg[MIPS_CP0_ERROR_PC][0]);
+
+       return 0;
+}
+
+static int
+kvm_trap_emul_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
+{
+       struct mips_coproc *cop0 = vcpu->arch.cop0;
+
+       regs->cp0reg[MIPS_CP0_TLB_INDEX][0] = kvm_read_c0_guest_index(cop0);
+       regs->cp0reg[MIPS_CP0_TLB_CONTEXT][0] = kvm_read_c0_guest_context(cop0);
+       regs->cp0reg[MIPS_CP0_BAD_VADDR][0] = kvm_read_c0_guest_badvaddr(cop0);
+       regs->cp0reg[MIPS_CP0_TLB_HI][0] = kvm_read_c0_guest_entryhi(cop0);
+       regs->cp0reg[MIPS_CP0_EXC_PC][0] = kvm_read_c0_guest_epc(cop0);
+
+       regs->cp0reg[MIPS_CP0_STATUS][0] = kvm_read_c0_guest_status(cop0);
+       regs->cp0reg[MIPS_CP0_CAUSE][0] = kvm_read_c0_guest_cause(cop0);
+       regs->cp0reg[MIPS_CP0_TLB_PG_MASK][0] =
+           kvm_read_c0_guest_pagemask(cop0);
+       regs->cp0reg[MIPS_CP0_TLB_WIRED][0] = kvm_read_c0_guest_wired(cop0);
+       regs->cp0reg[MIPS_CP0_ERROR_PC][0] = kvm_read_c0_guest_errorepc(cop0);
+
+       regs->cp0reg[MIPS_CP0_CONFIG][0] = kvm_read_c0_guest_config(cop0);
+       regs->cp0reg[MIPS_CP0_CONFIG][1] = kvm_read_c0_guest_config1(cop0);
+       regs->cp0reg[MIPS_CP0_CONFIG][2] = kvm_read_c0_guest_config2(cop0);
+       regs->cp0reg[MIPS_CP0_CONFIG][3] = kvm_read_c0_guest_config3(cop0);
+       regs->cp0reg[MIPS_CP0_CONFIG][7] = kvm_read_c0_guest_config7(cop0);
+
+       return 0;
+}
+
+static int kvm_trap_emul_vm_init(struct kvm *kvm)
+{
+       return 0;
+}
+
+static int kvm_trap_emul_vcpu_init(struct kvm_vcpu *vcpu)
+{
+       return 0;
+}
+
+static int kvm_trap_emul_vcpu_setup(struct kvm_vcpu *vcpu)
+{
+       struct mips_coproc *cop0 = vcpu->arch.cop0;
+       uint32_t config1;
+       int vcpu_id = vcpu->vcpu_id;
+
+       /* Arch specific stuff, set up config registers properly so that the
+        * guest will come up as expected, for now we simulate a
+        * MIPS 24kc
+        */
+       kvm_write_c0_guest_prid(cop0, 0x00019300);
+       kvm_write_c0_guest_config(cop0,
+                                 MIPS_CONFIG0 | (0x1 << CP0C0_AR) |
+                                 (MMU_TYPE_R4000 << CP0C0_MT));
+
+       /* Read the cache characteristics from the host Config1 Register */
+       config1 = (read_c0_config1() & ~0x7f);
+
+       /* Set up MMU size */
+       config1 &= ~(0x3f << 25);
+       config1 |= ((KVM_MIPS_GUEST_TLB_SIZE - 1) << 25);
+
+       /* We unset some bits that we aren't emulating */
+       config1 &=
+           ~((1 << CP0C1_C2) | (1 << CP0C1_MD) | (1 << CP0C1_PC) |
+             (1 << CP0C1_WR) | (1 << CP0C1_CA));
+       kvm_write_c0_guest_config1(cop0, config1);
+
+       kvm_write_c0_guest_config2(cop0, MIPS_CONFIG2);
+       /* MIPS_CONFIG2 | (read_c0_config2() & 0xfff) */
+       kvm_write_c0_guest_config3(cop0,
+                                  MIPS_CONFIG3 | (0 << CP0C3_VInt) | (1 <<
+                                                                      CP0C3_ULRI));
+
+       /* Set Wait IE/IXMT Ignore in Config7, IAR, AR */
+       kvm_write_c0_guest_config7(cop0, (MIPS_CONF7_WII) | (1 << 10));
+
+       /* Setup IntCtl defaults, compatibilty mode for timer interrupts (HW5) */
+       kvm_write_c0_guest_intctl(cop0, 0xFC000000);
+
+       /* Put in vcpu id as CPUNum into Ebase Reg to handle SMP Guests */
+       kvm_write_c0_guest_ebase(cop0, KVM_GUEST_KSEG0 | (vcpu_id & 0xFF));
+
+       return 0;
+}
+
+static struct kvm_mips_callbacks kvm_trap_emul_callbacks = {
+       /* exit handlers */
+       .handle_cop_unusable = kvm_trap_emul_handle_cop_unusable,
+       .handle_tlb_mod = kvm_trap_emul_handle_tlb_mod,
+       .handle_tlb_st_miss = kvm_trap_emul_handle_tlb_st_miss,
+       .handle_tlb_ld_miss = kvm_trap_emul_handle_tlb_ld_miss,
+       .handle_addr_err_st = kvm_trap_emul_handle_addr_err_st,
+       .handle_addr_err_ld = kvm_trap_emul_handle_addr_err_ld,
+       .handle_syscall = kvm_trap_emul_handle_syscall,
+       .handle_res_inst = kvm_trap_emul_handle_res_inst,
+       .handle_break = kvm_trap_emul_handle_break,
+
+       .vm_init = kvm_trap_emul_vm_init,
+       .vcpu_init = kvm_trap_emul_vcpu_init,
+       .vcpu_setup = kvm_trap_emul_vcpu_setup,
+       .gva_to_gpa = kvm_trap_emul_gva_to_gpa_cb,
+       .queue_timer_int = kvm_mips_queue_timer_int_cb,
+       .dequeue_timer_int = kvm_mips_dequeue_timer_int_cb,
+       .queue_io_int = kvm_mips_queue_io_int_cb,
+       .dequeue_io_int = kvm_mips_dequeue_io_int_cb,
+       .irq_deliver = kvm_mips_irq_deliver_cb,
+       .irq_clear = kvm_mips_irq_clear_cb,
+       .vcpu_ioctl_get_regs = kvm_trap_emul_ioctl_get_regs,
+       .vcpu_ioctl_set_regs = kvm_trap_emul_ioctl_set_regs,
+};
+
+int kvm_mips_emulation_init(struct kvm_mips_callbacks **install_callbacks)
+{
+       *install_callbacks = &kvm_trap_emul_callbacks;
+       return 0;
+}