/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2011 NetApp, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "opt_bhyve_snapshot.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <sys/malloc.h>
#include <sys/pcpu.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/rwlock.h>
#include <sys/sched.h>
#include <sys/smp.h>
#include <sys/sx.h>
#include <sys/vnode.h>

#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_extern.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_pager.h>
#include <vm/vm_kern.h>
#include <vm/vnode_pager.h>
#include <vm/swap_pager.h>
#include <vm/uma.h>

#include <machine/cpu.h>
#include <machine/pcb.h>
#include <machine/smp.h>
#include <machine/md_var.h>
#include <x86/psl.h>
#include <x86/apicreg.h>
#include <x86/ifunc.h>

#include <machine/vmm.h>
#include <machine/vmm_instruction_emul.h>
#include <machine/vmm_snapshot.h>

#include <dev/vmm/vmm_dev.h>
#include <dev/vmm/vmm_ktr.h>
#include <dev/vmm/vmm_mem.h>
#include <dev/vmm/vmm_vm.h>

#include "vmm_ioport.h"
#include "vmm_host.h"
#include "vmm_mem.h"
#include "vmm_util.h"
#include "vatpic.h"
#include "vatpit.h"
#include "vhpet.h"
#include "vioapic.h"
#include "vlapic.h"
#include "vpmtmr.h"
#include "vrtc.h"
#include "vmm_stat.h"
#include "vmm_lapic.h"

#include "io/ppt.h"
#include "io/iommu.h"

struct vlapic;

#define VMM_CTR0(vcpu, format)                                          \
        VCPU_CTR0((vcpu)->vm, (vcpu)->vcpuid, format)

#define VMM_CTR1(vcpu, format, p1)                                      \
        VCPU_CTR1((vcpu)->vm, (vcpu)->vcpuid, format, p1)

#define VMM_CTR2(vcpu, format, p1, p2)                                  \
        VCPU_CTR2((vcpu)->vm, (vcpu)->vcpuid, format, p1, p2)

#define VMM_CTR3(vcpu, format, p1, p2, p3)                              \
        VCPU_CTR3((vcpu)->vm, (vcpu)->vcpuid, format, p1, p2, p3)

#define VMM_CTR4(vcpu, format, p1, p2, p3, p4)                          \
        VCPU_CTR4((vcpu)->vm, (vcpu)->vcpuid, format, p1, p2, p3, p4)

static void     vmmops_panic(void);

static void
vmmops_panic(void)
{
        panic("vmm_ops func called when !vmm_is_intel() && !vmm_is_svm()");
}

#define DEFINE_VMMOPS_IFUNC(ret_type, opname, args)                     \
    DEFINE_IFUNC(, ret_type, vmmops_##opname, args)                     \
    {                                                                   \
        if (vmm_is_intel())                                             \
                return (vmm_ops_intel.opname);                          \
        else if (vmm_is_svm())                                          \
                return (vmm_ops_amd.opname);                            \
        else                                                            \
                return ((ret_type (*)args)vmmops_panic);                \
    }

DEFINE_VMMOPS_IFUNC(int, modinit, (int ipinum))
DEFINE_VMMOPS_IFUNC(int, modcleanup, (void))
DEFINE_VMMOPS_IFUNC(void, modsuspend, (void))
DEFINE_VMMOPS_IFUNC(void, modresume, (void))
DEFINE_VMMOPS_IFUNC(void *, init, (struct vm *vm, struct pmap *pmap))
DEFINE_VMMOPS_IFUNC(int, run, (void *vcpui, register_t rip, struct pmap *pmap,
    struct vm_eventinfo *info))
DEFINE_VMMOPS_IFUNC(void, cleanup, (void *vmi))
DEFINE_VMMOPS_IFUNC(void *, vcpu_init, (void *vmi, struct vcpu *vcpu,
    int vcpu_id))
DEFINE_VMMOPS_IFUNC(void, vcpu_cleanup, (void *vcpui))
DEFINE_VMMOPS_IFUNC(int, getreg, (void *vcpui, int num, uint64_t *retval))
DEFINE_VMMOPS_IFUNC(int, setreg, (void *vcpui, int num, uint64_t val))
DEFINE_VMMOPS_IFUNC(int, getdesc, (void *vcpui, int num, struct seg_desc *desc))
DEFINE_VMMOPS_IFUNC(int, setdesc, (void *vcpui, int num, struct seg_desc *desc))
DEFINE_VMMOPS_IFUNC(int, getcap, (void *vcpui, int num, int *retval))
DEFINE_VMMOPS_IFUNC(int, setcap, (void *vcpui, int num, int val))
DEFINE_VMMOPS_IFUNC(struct vmspace *, vmspace_alloc, (vm_offset_t min,
    vm_offset_t max))
DEFINE_VMMOPS_IFUNC(void, vmspace_free, (struct vmspace *vmspace))
DEFINE_VMMOPS_IFUNC(struct vlapic *, vlapic_init, (void *vcpui))
DEFINE_VMMOPS_IFUNC(void, vlapic_cleanup, (struct vlapic *vlapic))
#ifdef BHYVE_SNAPSHOT
DEFINE_VMMOPS_IFUNC(int, vcpu_snapshot, (void *vcpui,
    struct vm_snapshot_meta *meta))
DEFINE_VMMOPS_IFUNC(int, restore_tsc, (void *vcpui, uint64_t now))
#endif

SDT_PROVIDER_DEFINE(vmm);

static MALLOC_DEFINE(M_VM, "vm", "vm");

/* statistics */
static VMM_STAT(VCPU_TOTAL_RUNTIME, "vcpu total runtime");

SYSCTL_DECL(_hw_vmm);

/*
 * Halt the guest if all vcpus are executing a HLT instruction with
 * interrupts disabled.
 */
static int halt_detection_enabled = 1;
SYSCTL_INT(_hw_vmm, OID_AUTO, halt_detection, CTLFLAG_RDTUN,
    &halt_detection_enabled, 0,
    "Halt VM if all vcpus execute HLT with interrupts disabled");

static int trace_guest_exceptions;
SYSCTL_INT(_hw_vmm, OID_AUTO, trace_guest_exceptions, CTLFLAG_RDTUN,
    &trace_guest_exceptions, 0,
    "Trap into hypervisor on all guest exceptions and reflect them back");

static int trap_wbinvd;
SYSCTL_INT(_hw_vmm, OID_AUTO, trap_wbinvd, CTLFLAG_RDTUN, &trap_wbinvd, 0,
    "WBINVD triggers a VM-exit");

/* global statistics */
VMM_STAT(VCPU_MIGRATIONS, "vcpu migration across host cpus");
VMM_STAT(VMEXIT_COUNT, "total number of vm exits");
VMM_STAT(VMEXIT_EXTINT, "vm exits due to external interrupt");
VMM_STAT(VMEXIT_HLT, "number of times hlt was intercepted");
VMM_STAT(VMEXIT_CR_ACCESS, "number of times %cr access was intercepted");
VMM_STAT(VMEXIT_RDMSR, "number of times rdmsr was intercepted");
VMM_STAT(VMEXIT_WRMSR, "number of times wrmsr was intercepted");
VMM_STAT(VMEXIT_MTRAP, "number of monitor trap exits");
VMM_STAT(VMEXIT_PAUSE, "number of times pause was intercepted");
VMM_STAT(VMEXIT_INTR_WINDOW, "vm exits due to interrupt window opening");
VMM_STAT(VMEXIT_NMI_WINDOW, "vm exits due to nmi window opening");
VMM_STAT(VMEXIT_INOUT, "number of times in/out was intercepted");
VMM_STAT(VMEXIT_CPUID, "number of times cpuid was intercepted");
VMM_STAT(VMEXIT_NESTED_FAULT, "vm exits due to nested page fault");
VMM_STAT(VMEXIT_INST_EMUL, "vm exits for instruction emulation");
VMM_STAT(VMEXIT_UNKNOWN, "number of vm exits for unknown reason");
VMM_STAT(VMEXIT_ASTPENDING, "number of times astpending at exit");
VMM_STAT(VMEXIT_REQIDLE, "number of times idle requested at exit");
VMM_STAT(VMEXIT_USERSPACE, "number of vm exits handled in userspace");
VMM_STAT(VMEXIT_RENDEZVOUS, "number of times rendezvous pending at exit");
VMM_STAT(VMEXIT_EXCEPTION, "number of vm exits due to exceptions");

static void
vcpu_cleanup(struct vcpu *vcpu, bool destroy)
{
        vmmops_vlapic_cleanup(vcpu->vlapic);
        vmmops_vcpu_cleanup(vcpu->cookie);
        vcpu->cookie = NULL;
        if (destroy) {
                vmm_stat_free(vcpu->stats);
                fpu_save_area_free(vcpu->guestfpu);
                vcpu_lock_destroy(vcpu);
                free(vcpu, M_VM);
        }
}

static struct vcpu *
vcpu_alloc(struct vm *vm, int vcpu_id)
{
        struct vcpu *vcpu;

        KASSERT(vcpu_id >= 0 && vcpu_id < vm->maxcpus,
            ("vcpu_init: invalid vcpu %d", vcpu_id));

        vcpu = malloc(sizeof(*vcpu), M_VM, M_WAITOK | M_ZERO);
        vcpu_lock_init(vcpu);
        vcpu->state = VCPU_IDLE;
        vcpu->hostcpu = NOCPU;
        vcpu->vcpuid = vcpu_id;
        vcpu->vm = vm;
        vcpu->guestfpu = fpu_save_area_alloc();
        vcpu->stats = vmm_stat_alloc();
        vcpu->tsc_offset = 0;
        return (vcpu);
}

static void
vcpu_init(struct vcpu *vcpu)
{
        vcpu->cookie = vmmops_vcpu_init(vcpu->vm->cookie, vcpu, vcpu->vcpuid);
        vcpu->vlapic = vmmops_vlapic_init(vcpu->cookie);
        vm_set_x2apic_state(vcpu, X2APIC_DISABLED);
        vcpu->reqidle = 0;
        vcpu->exitintinfo = 0;
        vcpu->nmi_pending = 0;
        vcpu->extint_pending = 0;
        vcpu->exception_pending = 0;
        vcpu->guest_xcr0 = XFEATURE_ENABLED_X87;
        fpu_save_area_reset(vcpu->guestfpu);
        vmm_stat_init(vcpu->stats);
}

int
vcpu_trace_exceptions(struct vcpu *vcpu)
{
        return (trace_guest_exceptions);
}

int
vcpu_trap_wbinvd(struct vcpu *vcpu)
{
        return (trap_wbinvd);
}

struct vm_exit *
vm_exitinfo(struct vcpu *vcpu)
{
        return (&vcpu->exitinfo);
}

cpuset_t *
vm_exitinfo_cpuset(struct vcpu *vcpu)
{
        return (&vcpu->exitinfo_cpuset);
}

int
vmm_modinit(void)
{
        if (!vmm_is_hw_supported())
                return (ENXIO);

        vmm_host_state_init();

        vmm_ipinum = lapic_ipi_alloc(pti ? &IDTVEC(justreturn1_pti) :
            &IDTVEC(justreturn));
        if (vmm_ipinum < 0)
                vmm_ipinum = IPI_AST;

        vmm_suspend_p = vmmops_modsuspend;
        vmm_resume_p = vmmops_modresume;

        return (vmmops_modinit(vmm_ipinum));
}

int
vmm_modcleanup(void)
{
        vmm_suspend_p = NULL;
        vmm_resume_p = NULL;
        iommu_cleanup();
        if (vmm_ipinum != IPI_AST)
                lapic_ipi_free(vmm_ipinum);
        return (vmmops_modcleanup());
}

static void
vm_init(struct vm *vm, bool create)
{
        vm->cookie = vmmops_init(vm, vmspace_pmap(vm_vmspace(vm)));
        vm->iommu = NULL;
        vm->vioapic = vioapic_init(vm);
        vm->vhpet = vhpet_init(vm);
        vm->vatpic = vatpic_init(vm);
        vm->vatpit = vatpit_init(vm);
        vm->vpmtmr = vpmtmr_init(vm);
        if (create)
                vm->vrtc = vrtc_init(vm);

        CPU_ZERO(&vm->active_cpus);
        CPU_ZERO(&vm->debug_cpus);
        CPU_ZERO(&vm->startup_cpus);

        vm->suspend = 0;
        CPU_ZERO(&vm->suspended_cpus);

        if (!create) {
                for (int i = 0; i < vm->maxcpus; i++) {
                        if (vm->vcpu[i] != NULL)
                                vcpu_init(vm->vcpu[i]);
                }
        }
}

struct vcpu *
vm_alloc_vcpu(struct vm *vm, int vcpuid)
{
        struct vcpu *vcpu;

        if (vcpuid < 0 || vcpuid >= vm_get_maxcpus(vm))
                return (NULL);

        vcpu = (struct vcpu *)
            atomic_load_acq_ptr((uintptr_t *)&vm->vcpu[vcpuid]);
        if (__predict_true(vcpu != NULL))
                return (vcpu);

        sx_xlock(&vm->vcpus_init_lock);
        vcpu = vm->vcpu[vcpuid];
        if (vcpu == NULL && !vm->dying) {
                vcpu = vcpu_alloc(vm, vcpuid);
                vcpu_init(vcpu);

                /*
                 * Ensure vCPU is fully created before updating pointer
                 * to permit unlocked reads above.
                 */
                atomic_store_rel_ptr((uintptr_t *)&vm->vcpu[vcpuid],
                    (uintptr_t)vcpu);
        }
        sx_xunlock(&vm->vcpus_init_lock);
        return (vcpu);
}

int
vm_create(const char *name, struct vm **retvm)
{
        struct vm *vm;
        int error;

        vm = malloc(sizeof(struct vm), M_VM, M_WAITOK | M_ZERO);
        error = vm_mem_init(&vm->mem, 0, VM_MAXUSER_ADDRESS_LA48);
        if (error != 0) {
                free(vm, M_VM);
                return (error);
        }
        strcpy(vm->name, name);
        mtx_init(&vm->rendezvous_mtx, "vm rendezvous lock", 0, MTX_DEF);
        sx_init(&vm->vcpus_init_lock, "vm vcpus");
        vm->vcpu = malloc(sizeof(*vm->vcpu) * vm_maxcpu, M_VM, M_WAITOK |
            M_ZERO);

        vm->sockets = 1;
        vm->cores = 1;          /* XXX backwards compatibility */
        vm->threads = 1;        /* XXX backwards compatibility */
        vm->maxcpus = vm_maxcpu;

        vm_init(vm, true);

        *retvm = vm;
        return (0);
}

static void
vm_cleanup(struct vm *vm, bool destroy)
{
        if (destroy)
                vm_xlock_memsegs(vm);
        else
                vm_assert_memseg_xlocked(vm);

        ppt_unassign_all(vm);

        if (vm->iommu != NULL)
                iommu_destroy_domain(vm->iommu);

        if (destroy)
                vrtc_cleanup(vm->vrtc);
        else
                vrtc_reset(vm->vrtc);
        vpmtmr_cleanup(vm->vpmtmr);
        vatpit_cleanup(vm->vatpit);
        vhpet_cleanup(vm->vhpet);
        vatpic_cleanup(vm->vatpic);
        vioapic_cleanup(vm->vioapic);

        for (int i = 0; i < vm->maxcpus; i++) {
                if (vm->vcpu[i] != NULL)
                        vcpu_cleanup(vm->vcpu[i], destroy);
        }

        vmmops_cleanup(vm->cookie);

        vm_mem_cleanup(vm);

        if (destroy) {
                vm_mem_destroy(vm);

                free(vm->vcpu, M_VM);
                sx_destroy(&vm->vcpus_init_lock);
                mtx_destroy(&vm->rendezvous_mtx);
        }
}

void
vm_destroy(struct vm *vm)
{
        vm_cleanup(vm, true);
        free(vm, M_VM);
}

void
vm_reset(struct vm *vm)
{
        vm_cleanup(vm, false);
        vm_init(vm, false);
}

int
vm_map_mmio(struct vm *vm, vm_paddr_t gpa, size_t len, vm_paddr_t hpa)
{
        return (vmm_mmio_alloc(vm_vmspace(vm), gpa, len, hpa));
}

int
vm_unmap_mmio(struct vm *vm, vm_paddr_t gpa, size_t len)
{

        vmm_mmio_free(vm_vmspace(vm), gpa, len);
        return (0);
}

static int
vm_iommu_map(struct vm *vm)
{
        pmap_t pmap;
        vm_paddr_t gpa, hpa;
        struct vm_mem_map *mm;
        int error, i;

        sx_assert(&vm->mem.mem_segs_lock, SX_LOCKED);

        pmap = vmspace_pmap(vm_vmspace(vm));
        for (i = 0; i < VM_MAX_MEMMAPS; i++) {
                mm = &vm->mem.mem_maps[i];
                if (!vm_memseg_sysmem(vm, mm->segid))
                        continue;

                KASSERT((mm->flags & VM_MEMMAP_F_IOMMU) == 0,
                    ("iommu map found invalid memmap %#lx/%#lx/%#x",
                    mm->gpa, mm->len, mm->flags));
                if ((mm->flags & VM_MEMMAP_F_WIRED) == 0)
                        continue;
                mm->flags |= VM_MEMMAP_F_IOMMU;

                for (gpa = mm->gpa; gpa < mm->gpa + mm->len; gpa += PAGE_SIZE) {
                        hpa = pmap_extract(pmap, gpa);

                        /*
                         * All mappings in the vmm vmspace must be
                         * present since they are managed by vmm in this way.
                         * Because we are in pass-through mode, the
                         * mappings must also be wired.  This implies
                         * that all pages must be mapped and wired,
                         * allowing to use pmap_extract() and avoiding the
                         * need to use vm_gpa_hold_global().
                         *
                         * This could change if/when we start
                         * supporting page faults on IOMMU maps.
                         */
                        KASSERT(vm_page_wired(PHYS_TO_VM_PAGE(hpa)),
                            ("vm_iommu_map: vm %p gpa %jx hpa %jx not wired",
                            vm, (uintmax_t)gpa, (uintmax_t)hpa));

                        iommu_create_mapping(vm->iommu, gpa, hpa, PAGE_SIZE);
                }
        }

        error = iommu_invalidate_tlb(iommu_host_domain());
        return (error);
}

static int
vm_iommu_unmap(struct vm *vm)
{
        vm_paddr_t gpa;
        struct vm_mem_map *mm;
        int error, i;

        sx_assert(&vm->mem.mem_segs_lock, SX_LOCKED);

        for (i = 0; i < VM_MAX_MEMMAPS; i++) {
                mm = &vm->mem.mem_maps[i];
                if (!vm_memseg_sysmem(vm, mm->segid))
                        continue;

                if ((mm->flags & VM_MEMMAP_F_IOMMU) == 0)
                        continue;
                mm->flags &= ~VM_MEMMAP_F_IOMMU;
                KASSERT((mm->flags & VM_MEMMAP_F_WIRED) != 0,
                    ("iommu unmap found invalid memmap %#lx/%#lx/%#x",
                    mm->gpa, mm->len, mm->flags));

                for (gpa = mm->gpa; gpa < mm->gpa + mm->len; gpa += PAGE_SIZE) {
                        KASSERT(vm_page_wired(PHYS_TO_VM_PAGE(pmap_extract(
                            vmspace_pmap(vm_vmspace(vm)), gpa))),
                            ("vm_iommu_unmap: vm %p gpa %jx not wired",
                            vm, (uintmax_t)gpa));
                        iommu_remove_mapping(vm->iommu, gpa, PAGE_SIZE);
                }
        }

        /*
         * Invalidate the cached translations associated with the domain
         * from which pages were removed.
         */
        error = iommu_invalidate_tlb(vm->iommu);
        return (error);
}

int
vm_unassign_pptdev(struct vm *vm, int bus, int slot, int func)
{
        int error;

        error = ppt_unassign_device(vm, bus, slot, func);
        if (error)
                return (error);

        if (ppt_assigned_devices(vm) == 0)
                error = vm_iommu_unmap(vm);

        return (error);
}

int
vm_assign_pptdev(struct vm *vm, int bus, int slot, int func)
{
        int error;
        vm_paddr_t maxaddr;
        bool map = false;

        /* Set up the IOMMU to do the 'gpa' to 'hpa' translation */
        if (ppt_assigned_devices(vm) == 0) {
                KASSERT(vm->iommu == NULL,
                    ("vm_assign_pptdev: iommu must be NULL"));
                maxaddr = vmm_sysmem_maxaddr(vm);
                vm->iommu = iommu_create_domain(maxaddr);
                if (vm->iommu == NULL)
                        return (ENXIO);
                map = true;
        }

        error = ppt_assign_device(vm, bus, slot, func);
        if (error == 0 && map)
                error = vm_iommu_map(vm);
        return (error);
}

int
vm_get_register(struct vcpu *vcpu, int reg, uint64_t *retval)
{
        /* Negative values represent VM control structure fields. */
        if (reg >= VM_REG_LAST)
                return (EINVAL);

        return (vmmops_getreg(vcpu->cookie, reg, retval));
}

int
vm_set_register(struct vcpu *vcpu, int reg, uint64_t val)
{
        int error;

        /* Negative values represent VM control structure fields. */
        if (reg >= VM_REG_LAST)
                return (EINVAL);

        error = vmmops_setreg(vcpu->cookie, reg, val);
        if (error || reg != VM_REG_GUEST_RIP)
                return (error);

        /* Set 'nextrip' to match the value of %rip */
        VMM_CTR1(vcpu, "Setting nextrip to %#lx", val);
        vcpu->nextrip = val;
        return (0);
}

static bool
is_descriptor_table(int reg)
{

        switch (reg) {
        case VM_REG_GUEST_IDTR:
        case VM_REG_GUEST_GDTR:
                return (true);
        default:
                return (false);
        }
}

static bool
is_segment_register(int reg)
{

        switch (reg) {
        case VM_REG_GUEST_ES:
        case VM_REG_GUEST_CS:
        case VM_REG_GUEST_SS:
        case VM_REG_GUEST_DS:
        case VM_REG_GUEST_FS:
        case VM_REG_GUEST_GS:
        case VM_REG_GUEST_TR:
        case VM_REG_GUEST_LDTR:
                return (true);
        default:
                return (false);
        }
}

int
vm_get_seg_desc(struct vcpu *vcpu, int reg, struct seg_desc *desc)
{

        if (!is_segment_register(reg) && !is_descriptor_table(reg))
                return (EINVAL);

        return (vmmops_getdesc(vcpu->cookie, reg, desc));
}

int
vm_set_seg_desc(struct vcpu *vcpu, int reg, struct seg_desc *desc)
{

        if (!is_segment_register(reg) && !is_descriptor_table(reg))
                return (EINVAL);

        return (vmmops_setdesc(vcpu->cookie, reg, desc));
}

static void
restore_guest_fpustate(struct vcpu *vcpu)
{

        /* flush host state to the pcb */
        fpuexit(curthread);

        /* restore guest FPU state */
        fpu_enable();
        fpurestore(vcpu->guestfpu);

        /* restore guest XCR0 if XSAVE is enabled in the host */
        if (rcr4() & CR4_XSAVE)
                load_xcr(0, vcpu->guest_xcr0);

        /*
         * The FPU is now "dirty" with the guest's state so disable
         * the FPU to trap any access by the host.
         */
        fpu_disable();
}

static void
save_guest_fpustate(struct vcpu *vcpu)
{

        if ((rcr0() & CR0_TS) == 0)
                panic("fpu emulation not enabled in host!");

        /* save guest XCR0 and restore host XCR0 */
        if (rcr4() & CR4_XSAVE) {
                vcpu->guest_xcr0 = rxcr(0);
                load_xcr(0, vmm_get_host_xcr0());
        }

        /* save guest FPU state */
        fpu_enable();
        fpusave(vcpu->guestfpu);
        fpu_disable();
}

static VMM_STAT(VCPU_IDLE_TICKS, "number of ticks vcpu was idle");

static void
vcpu_require_state(struct vcpu *vcpu, enum vcpu_state newstate)
{
        int error;

        if ((error = vcpu_set_state(vcpu, newstate, false)) != 0)
                panic("Error %d setting state to %d\n", error, newstate);
}

static void
vcpu_require_state_locked(struct vcpu *vcpu, enum vcpu_state newstate)
{
        int error;

        if ((error = vcpu_set_state_locked(vcpu, newstate, false)) != 0)
                panic("Error %d setting state to %d", error, newstate);
}

/*
 * Emulate a guest 'hlt' by sleeping until the vcpu is ready to run.
 */
static int
vm_handle_hlt(struct vcpu *vcpu, bool intr_disabled, bool *retu)
{
        struct vm *vm = vcpu->vm;
        const char *wmesg;
        struct thread *td;
        int error, t, vcpuid, vcpu_halted, vm_halted;

        vcpuid = vcpu->vcpuid;
        vcpu_halted = 0;
        vm_halted = 0;
        error = 0;
        td = curthread;

        KASSERT(!CPU_ISSET(vcpuid, &vm->halted_cpus), ("vcpu already halted"));

        vcpu_lock(vcpu);
        while (1) {
                /*
                 * Do a final check for pending NMI or interrupts before
                 * really putting this thread to sleep. Also check for
                 * software events that would cause this vcpu to wakeup.
                 *
                 * These interrupts/events could have happened after the
                 * vcpu returned from vmmops_run() and before it acquired the
                 * vcpu lock above.
                 */
                if (vm->rendezvous_func != NULL || vm->suspend || vcpu->reqidle)
                        break;
                if (vm_nmi_pending(vcpu))
                        break;
                if (!intr_disabled) {
                        if (vm_extint_pending(vcpu) ||
                            vlapic_pending_intr(vcpu->vlapic, NULL)) {
                                break;
                        }
                }

                /* Don't go to sleep if the vcpu thread needs to yield */
                if (vcpu_should_yield(vcpu))
                        break;

                if (vcpu_debugged(vcpu))
                        break;

                /*
                 * Some Linux guests implement "halt" by having all vcpus
                 * execute HLT with interrupts disabled. 'halted_cpus' keeps
                 * track of the vcpus that have entered this state. When all
                 * vcpus enter the halted state the virtual machine is halted.
                 */
                if (intr_disabled) {
                        wmesg = "vmhalt";
                        VMM_CTR0(vcpu, "Halted");
                        if (!vcpu_halted && halt_detection_enabled) {
                                vcpu_halted = 1;
                                CPU_SET_ATOMIC(vcpuid, &vm->halted_cpus);
                        }
                        if (CPU_CMP(&vm->halted_cpus, &vm->active_cpus) == 0) {
                                vm_halted = 1;
                                break;
                        }
                } else {
                        wmesg = "vmidle";
                }

                t = ticks;
                vcpu_require_state_locked(vcpu, VCPU_SLEEPING);
                /*
                 * XXX msleep_spin() cannot be interrupted by signals so
                 * wake up periodically to check pending signals.
                 */
                msleep_spin(vcpu, &vcpu->mtx, wmesg, hz);
                vcpu_require_state_locked(vcpu, VCPU_FROZEN);
                vmm_stat_incr(vcpu, VCPU_IDLE_TICKS, ticks - t);
                if (td_ast_pending(td, TDA_SUSPEND)) {
                        vcpu_unlock(vcpu);
                        error = thread_check_susp(td, false);
                        if (error != 0) {
                                if (vcpu_halted) {
                                        CPU_CLR_ATOMIC(vcpuid,
                                            &vm->halted_cpus);
                                }
                                return (error);
                        }
                        vcpu_lock(vcpu);
                }
        }

        if (vcpu_halted)
                CPU_CLR_ATOMIC(vcpuid, &vm->halted_cpus);

        vcpu_unlock(vcpu);

        if (vm_halted)
                vm_suspend(vm, VM_SUSPEND_HALT);

        return (0);
}

static int
vm_handle_paging(struct vcpu *vcpu, bool *retu)
{
        struct vm *vm = vcpu->vm;
        int rv, ftype;
        struct vm_map *map;
        struct vm_exit *vme;

        vme = &vcpu->exitinfo;

        KASSERT(vme->inst_length == 0, ("%s: invalid inst_length %d",
            __func__, vme->inst_length));

        ftype = vme->u.paging.fault_type;
        KASSERT(ftype == VM_PROT_READ ||
            ftype == VM_PROT_WRITE || ftype == VM_PROT_EXECUTE,
            ("vm_handle_paging: invalid fault_type %d", ftype));

        if (ftype == VM_PROT_READ || ftype == VM_PROT_WRITE) {
                rv = pmap_emulate_accessed_dirty(vmspace_pmap(vm_vmspace(vm)),
                    vme->u.paging.gpa, ftype);
                if (rv == 0) {
                        VMM_CTR2(vcpu, "%s bit emulation for gpa %#lx",
                            ftype == VM_PROT_READ ? "accessed" : "dirty",
                            vme->u.paging.gpa);
                        goto done;
                }
        }

        map = &vm_vmspace(vm)->vm_map;
        rv = vm_fault(map, vme->u.paging.gpa, ftype, VM_FAULT_NORMAL, NULL);

        VMM_CTR3(vcpu, "vm_handle_paging rv = %d, gpa = %#lx, "
            "ftype = %d", rv, vme->u.paging.gpa, ftype);

        if (rv != KERN_SUCCESS)
                return (EFAULT);
done:
        return (0);
}

static int
vm_handle_inst_emul(struct vcpu *vcpu, bool *retu)
{
        struct vie *vie;
        struct vm_exit *vme;
        uint64_t gla, gpa, cs_base;
        struct vm_guest_paging *paging;
        mem_region_read_t mread;
        mem_region_write_t mwrite;
        enum vm_cpu_mode cpu_mode;
        int cs_d, error, fault;

        vme = &vcpu->exitinfo;

        KASSERT(vme->inst_length == 0, ("%s: invalid inst_length %d",
            __func__, vme->inst_length));

        gla = vme->u.inst_emul.gla;
        gpa = vme->u.inst_emul.gpa;
        cs_base = vme->u.inst_emul.cs_base;
        cs_d = vme->u.inst_emul.cs_d;
        vie = &vme->u.inst_emul.vie;
        paging = &vme->u.inst_emul.paging;
        cpu_mode = paging->cpu_mode;

        VMM_CTR1(vcpu, "inst_emul fault accessing gpa %#lx", gpa);

        /* Fetch, decode and emulate the faulting instruction */
        if (vie->num_valid == 0) {
                error = vmm_fetch_instruction(vcpu, paging, vme->rip + cs_base,
                    VIE_INST_SIZE, vie, &fault);
        } else {
                /*
                 * The instruction bytes have already been copied into 'vie'
                 */
                error = fault = 0;
        }
        if (error || fault)
                return (error);

        if (vmm_decode_instruction(vcpu, gla, cpu_mode, cs_d, vie) != 0) {
                VMM_CTR1(vcpu, "Error decoding instruction at %#lx",
                    vme->rip + cs_base);
                *retu = true;       /* dump instruction bytes in userspace */
                return (0);
        }

        /*
         * Update 'nextrip' based on the length of the emulated instruction.
         */
        vme->inst_length = vie->num_processed;
        vcpu->nextrip += vie->num_processed;
        VMM_CTR1(vcpu, "nextrip updated to %#lx after instruction decoding",
            vcpu->nextrip);

        /* return to userland unless this is an in-kernel emulated device */
        if (gpa >= DEFAULT_APIC_BASE && gpa < DEFAULT_APIC_BASE + PAGE_SIZE) {
                mread = lapic_mmio_read;
                mwrite = lapic_mmio_write;
        } else if (gpa >= VIOAPIC_BASE && gpa < VIOAPIC_BASE + VIOAPIC_SIZE) {
                mread = vioapic_mmio_read;
                mwrite = vioapic_mmio_write;
        } else if (gpa >= VHPET_BASE && gpa < VHPET_BASE + VHPET_SIZE) {
                mread = vhpet_mmio_read;
                mwrite = vhpet_mmio_write;
        } else {
                *retu = true;
                return (0);
        }

        error = vmm_emulate_instruction(vcpu, gpa, vie, paging, mread, mwrite,
            retu);

        return (error);
}

static int
vm_handle_suspend(struct vcpu *vcpu, bool *retu)
{
        struct vm *vm = vcpu->vm;
        int error, i;
        struct thread *td;

        error = 0;
        td = curthread;

        CPU_SET_ATOMIC(vcpu->vcpuid, &vm->suspended_cpus);

        /*
         * Wait until all 'active_cpus' have suspended themselves.
         *
         * Since a VM may be suspended at any time including when one or
         * more vcpus are doing a rendezvous we need to call the rendezvous
         * handler while we are waiting to prevent a deadlock.
         */
        vcpu_lock(vcpu);
        while (error == 0) {
                if (CPU_CMP(&vm->suspended_cpus, &vm->active_cpus) == 0) {
                        VMM_CTR0(vcpu, "All vcpus suspended");
                        break;
                }

                if (vm->rendezvous_func == NULL) {
                        VMM_CTR0(vcpu, "Sleeping during suspend");
                        vcpu_require_state_locked(vcpu, VCPU_SLEEPING);
                        msleep_spin(vcpu, &vcpu->mtx, "vmsusp", hz);
                        vcpu_require_state_locked(vcpu, VCPU_FROZEN);
                        if (td_ast_pending(td, TDA_SUSPEND)) {
                                vcpu_unlock(vcpu);
                                error = thread_check_susp(td, false);
                                vcpu_lock(vcpu);
                        }
                } else {
                        VMM_CTR0(vcpu, "Rendezvous during suspend");
                        vcpu_unlock(vcpu);
                        error = vm_handle_rendezvous(vcpu);
                        vcpu_lock(vcpu);
                }
        }
        vcpu_unlock(vcpu);

        /*
         * Wakeup the other sleeping vcpus and return to userspace.
         */
        for (i = 0; i < vm->maxcpus; i++) {
                if (CPU_ISSET(i, &vm->suspended_cpus)) {
                        vcpu_notify_event(vm_vcpu(vm, i));
                }
        }

        *retu = true;
        return (error);
}

static int
vm_handle_reqidle(struct vcpu *vcpu, bool *retu)
{
        vcpu_lock(vcpu);
        KASSERT(vcpu->reqidle, ("invalid vcpu reqidle %d", vcpu->reqidle));
        vcpu->reqidle = 0;
        vcpu_unlock(vcpu);
        *retu = true;
        return (0);
}

static int
vm_handle_db(struct vcpu *vcpu, struct vm_exit *vme, bool *retu)
{
        int error, fault;
        uint64_t rsp;
        uint64_t rflags;
        struct vm_copyinfo copyinfo[2];

        *retu = true;
        if (!vme->u.dbg.pushf_intercept || vme->u.dbg.tf_shadow_val != 0) {
                return (0);
        }

        vm_get_register(vcpu, VM_REG_GUEST_RSP, &rsp);
        error = vm_copy_setup(vcpu, &vme->u.dbg.paging, rsp, sizeof(uint64_t),
            VM_PROT_RW, copyinfo, nitems(copyinfo), &fault);
        if (error != 0 || fault != 0) {
                *retu = false;
                return (EINVAL);
        }

        /* Read pushed rflags value from top of stack. */
        vm_copyin(copyinfo, &rflags, sizeof(uint64_t));

        /* Clear TF bit. */
        rflags &= ~(PSL_T);

        /* Write updated value back to memory. */
        vm_copyout(&rflags, copyinfo, sizeof(uint64_t));
        vm_copy_teardown(copyinfo, nitems(copyinfo));

        return (0);
}

void
vm_exit_suspended(struct vcpu *vcpu, uint64_t rip)
{
        struct vm *vm = vcpu->vm;
        struct vm_exit *vmexit;

        KASSERT(vm->suspend > VM_SUSPEND_NONE && vm->suspend < VM_SUSPEND_LAST,
            ("vm_exit_suspended: invalid suspend type %d", vm->suspend));

        vmexit = vm_exitinfo(vcpu);
        vmexit->rip = rip;
        vmexit->inst_length = 0;
        vmexit->exitcode = VM_EXITCODE_SUSPENDED;
        vmexit->u.suspended.how = vm->suspend;
}

void
vm_exit_debug(struct vcpu *vcpu, uint64_t rip)
{
        struct vm_exit *vmexit;

        vmexit = vm_exitinfo(vcpu);
        vmexit->rip = rip;
        vmexit->inst_length = 0;
        vmexit->exitcode = VM_EXITCODE_DEBUG;
}

void
vm_exit_rendezvous(struct vcpu *vcpu, uint64_t rip)
{
        struct vm_exit *vmexit;

        vmexit = vm_exitinfo(vcpu);
        vmexit->rip = rip;
        vmexit->inst_length = 0;
        vmexit->exitcode = VM_EXITCODE_RENDEZVOUS;
        vmm_stat_incr(vcpu, VMEXIT_RENDEZVOUS, 1);
}

void
vm_exit_reqidle(struct vcpu *vcpu, uint64_t rip)
{
        struct vm_exit *vmexit;

        vmexit = vm_exitinfo(vcpu);
        vmexit->rip = rip;
        vmexit->inst_length = 0;
        vmexit->exitcode = VM_EXITCODE_REQIDLE;
        vmm_stat_incr(vcpu, VMEXIT_REQIDLE, 1);
}

void
vm_exit_astpending(struct vcpu *vcpu, uint64_t rip)
{
        struct vm_exit *vmexit;

        vmexit = vm_exitinfo(vcpu);
        vmexit->rip = rip;
        vmexit->inst_length = 0;
        vmexit->exitcode = VM_EXITCODE_BOGUS;
        vmm_stat_incr(vcpu, VMEXIT_ASTPENDING, 1);
}

int
vm_run(struct vcpu *vcpu)
{
        struct vm *vm = vcpu->vm;
        struct vm_eventinfo evinfo;
        int error, vcpuid;
        struct pcb *pcb;
        uint64_t tscval;
        struct vm_exit *vme;
        bool retu, intr_disabled;
        pmap_t pmap;

        vcpuid = vcpu->vcpuid;

        if (!CPU_ISSET(vcpuid, &vm->active_cpus))
                return (EINVAL);

        if (CPU_ISSET(vcpuid, &vm->suspended_cpus))
                return (EINVAL);

        pmap = vmspace_pmap(vm_vmspace(vm));
        vme = &vcpu->exitinfo;
        evinfo.rptr = &vm->rendezvous_req_cpus;
        evinfo.sptr = &vm->suspend;
        evinfo.iptr = &vcpu->reqidle;
restart:
        critical_enter();

        KASSERT(!CPU_ISSET(curcpu, &pmap->pm_active),
            ("vm_run: absurd pm_active"));

        tscval = rdtsc();

        pcb = PCPU_GET(curpcb);
        set_pcb_flags(pcb, PCB_FULL_IRET);

        restore_guest_fpustate(vcpu);

        vcpu_require_state(vcpu, VCPU_RUNNING);
        error = vmmops_run(vcpu->cookie, vcpu->nextrip, pmap, &evinfo);
        vcpu_require_state(vcpu, VCPU_FROZEN);

        save_guest_fpustate(vcpu);

        vmm_stat_incr(vcpu, VCPU_TOTAL_RUNTIME, rdtsc() - tscval);

        critical_exit();

        if (error == 0) {
                retu = false;
                vcpu->nextrip = vme->rip + vme->inst_length;
                switch (vme->exitcode) {
                case VM_EXITCODE_REQIDLE:
                        error = vm_handle_reqidle(vcpu, &retu);
                        break;
                case VM_EXITCODE_SUSPENDED:
                        error = vm_handle_suspend(vcpu, &retu);
                        break;
                case VM_EXITCODE_IOAPIC_EOI:
                        vioapic_process_eoi(vm, vme->u.ioapic_eoi.vector);
                        break;
                case VM_EXITCODE_RENDEZVOUS:
                        error = vm_handle_rendezvous(vcpu);
                        break;
                case VM_EXITCODE_HLT:
                        intr_disabled = ((vme->u.hlt.rflags & PSL_I) == 0);
                        error = vm_handle_hlt(vcpu, intr_disabled, &retu);
                        break;
                case VM_EXITCODE_PAGING:
                        error = vm_handle_paging(vcpu, &retu);
                        break;
                case VM_EXITCODE_INST_EMUL:
                        error = vm_handle_inst_emul(vcpu, &retu);
                        break;
                case VM_EXITCODE_INOUT:
                case VM_EXITCODE_INOUT_STR:
                        error = vm_handle_inout(vcpu, vme, &retu);
                        break;
                case VM_EXITCODE_DB:
                        error = vm_handle_db(vcpu, vme, &retu);
                        break;
                case VM_EXITCODE_MONITOR:
                case VM_EXITCODE_MWAIT:
                case VM_EXITCODE_VMINSN:
                        vm_inject_ud(vcpu);
                        break;
                default:
                        retu = true;    /* handled in userland */
                        break;
                }
        }

        /*
         * VM_EXITCODE_INST_EMUL could access the apic which could transform the
         * exit code into VM_EXITCODE_IPI.
         */
        if (error == 0 && vme->exitcode == VM_EXITCODE_IPI)
                error = vm_handle_ipi(vcpu, vme, &retu);

        if (error == 0 && retu == false)
                goto restart;

        vmm_stat_incr(vcpu, VMEXIT_USERSPACE, 1);
        VMM_CTR2(vcpu, "retu %d/%d", error, vme->exitcode);

        return (error);
}

int
vm_restart_instruction(struct vcpu *vcpu)
{
        enum vcpu_state state;
        uint64_t rip;
        int error __diagused;

        state = vcpu_get_state(vcpu, NULL);
        if (state == VCPU_RUNNING) {
                /*
                 * When a vcpu is "running" the next instruction is determined
                 * by adding 'rip' and 'inst_length' in the vcpu's 'exitinfo'.
                 * Thus setting 'inst_length' to zero will cause the current
                 * instruction to be restarted.
                 */
                vcpu->exitinfo.inst_length = 0;
                VMM_CTR1(vcpu, "restarting instruction at %#lx by "
                    "setting inst_length to zero", vcpu->exitinfo.rip);
        } else if (state == VCPU_FROZEN) {
                /*
                 * When a vcpu is "frozen" it is outside the critical section
                 * around vmmops_run() and 'nextrip' points to the next
                 * instruction. Thus instruction restart is achieved by setting
                 * 'nextrip' to the vcpu's %rip.
                 */
                error = vm_get_register(vcpu, VM_REG_GUEST_RIP, &rip);
                KASSERT(!error, ("%s: error %d getting rip", __func__, error));
                VMM_CTR2(vcpu, "restarting instruction by updating "
                    "nextrip from %#lx to %#lx", vcpu->nextrip, rip);
                vcpu->nextrip = rip;
        } else {
                panic("%s: invalid state %d", __func__, state);
        }
        return (0);
}

int
vm_exit_intinfo(struct vcpu *vcpu, uint64_t info)
{
        int type, vector;

        if (info & VM_INTINFO_VALID) {
                type = info & VM_INTINFO_TYPE;
                vector = info & 0xff;
                if (type == VM_INTINFO_NMI && vector != IDT_NMI)
                        return (EINVAL);
                if (type == VM_INTINFO_HWEXCEPTION && vector >= 32)
                        return (EINVAL);
                if (info & VM_INTINFO_RSVD)
                        return (EINVAL);
        } else {
                info = 0;
        }
        VMM_CTR2(vcpu, "%s: info1(%#lx)", __func__, info);
        vcpu->exitintinfo = info;
        return (0);
}

enum exc_class {
        EXC_BENIGN,
        EXC_CONTRIBUTORY,
        EXC_PAGEFAULT
};

#define IDT_VE  20      /* Virtualization Exception (Intel specific) */

static enum exc_class
exception_class(uint64_t info)
{
        int type, vector;

        KASSERT(info & VM_INTINFO_VALID, ("intinfo must be valid: %#lx", info));
        type = info & VM_INTINFO_TYPE;
        vector = info & 0xff;

        /* Table 6-4, "Interrupt and Exception Classes", Intel SDM, Vol 3 */
        switch (type) {
        case VM_INTINFO_HWINTR:
        case VM_INTINFO_SWINTR:
        case VM_INTINFO_NMI:
                return (EXC_BENIGN);
        default:
                /*
                 * Hardware exception.
                 *
                 * SVM and VT-x use identical type values to represent NMI,
                 * hardware interrupt and software interrupt.
                 *
                 * SVM uses type '3' for all exceptions. VT-x uses type '3'
                 * for exceptions except #BP and #OF. #BP and #OF use a type
                 * value of '5' or '6'. Therefore we don't check for explicit
                 * values of 'type' to classify 'intinfo' into a hardware
                 * exception.
                 */
                break;
        }

        switch (vector) {
        case IDT_PF:
        case IDT_VE:
                return (EXC_PAGEFAULT);
        case IDT_DE:
        case IDT_TS:
        case IDT_NP:
        case IDT_SS:
        case IDT_GP:
                return (EXC_CONTRIBUTORY);
        default:
                return (EXC_BENIGN);
        }
}

static int
nested_fault(struct vcpu *vcpu, uint64_t info1, uint64_t info2,
    uint64_t *retinfo)
{
        enum exc_class exc1, exc2;
        int type1, vector1;

        KASSERT(info1 & VM_INTINFO_VALID, ("info1 %#lx is not valid", info1));
        KASSERT(info2 & VM_INTINFO_VALID, ("info2 %#lx is not valid", info2));

        /*
         * If an exception occurs while attempting to call the double-fault
         * handler the processor enters shutdown mode (aka triple fault).
         */
        type1 = info1 & VM_INTINFO_TYPE;
        vector1 = info1 & 0xff;
        if (type1 == VM_INTINFO_HWEXCEPTION && vector1 == IDT_DF) {
                VMM_CTR2(vcpu, "triple fault: info1(%#lx), info2(%#lx)",
                    info1, info2);
                vm_suspend(vcpu->vm, VM_SUSPEND_TRIPLEFAULT);
                *retinfo = 0;
                return (0);
        }

        /*
         * Table 6-5 "Conditions for Generating a Double Fault", Intel SDM, Vol3
         */
        exc1 = exception_class(info1);
        exc2 = exception_class(info2);
        if ((exc1 == EXC_CONTRIBUTORY && exc2 == EXC_CONTRIBUTORY) ||
            (exc1 == EXC_PAGEFAULT && exc2 != EXC_BENIGN)) {
                /* Convert nested fault into a double fault. */
                *retinfo = IDT_DF;
                *retinfo |= VM_INTINFO_VALID | VM_INTINFO_HWEXCEPTION;
                *retinfo |= VM_INTINFO_DEL_ERRCODE;
        } else {
                /* Handle exceptions serially */
                *retinfo = info2;
        }
        return (1);
}

static uint64_t
vcpu_exception_intinfo(struct vcpu *vcpu)
{
        uint64_t info = 0;

        if (vcpu->exception_pending) {
                info = vcpu->exc_vector & 0xff;
                info |= VM_INTINFO_VALID | VM_INTINFO_HWEXCEPTION;
                if (vcpu->exc_errcode_valid) {
                        info |= VM_INTINFO_DEL_ERRCODE;
                        info |= (uint64_t)vcpu->exc_errcode << 32;
                }
        }
        return (info);
}

int
vm_entry_intinfo(struct vcpu *vcpu, uint64_t *retinfo)
{
        uint64_t info1, info2;
        int valid;

        info1 = vcpu->exitintinfo;
        vcpu->exitintinfo = 0;

        info2 = 0;
        if (vcpu->exception_pending) {
                info2 = vcpu_exception_intinfo(vcpu);
                vcpu->exception_pending = 0;
                VMM_CTR2(vcpu, "Exception %d delivered: %#lx",
                    vcpu->exc_vector, info2);
        }

        if ((info1 & VM_INTINFO_VALID) && (info2 & VM_INTINFO_VALID)) {
                valid = nested_fault(vcpu, info1, info2, retinfo);
        } else if (info1 & VM_INTINFO_VALID) {
                *retinfo = info1;
                valid = 1;
        } else if (info2 & VM_INTINFO_VALID) {
                *retinfo = info2;
                valid = 1;
        } else {
                valid = 0;
        }

        if (valid) {
                VMM_CTR4(vcpu, "%s: info1(%#lx), info2(%#lx), "
                    "retinfo(%#lx)", __func__, info1, info2, *retinfo);
        }

        return (valid);
}

int
vm_get_intinfo(struct vcpu *vcpu, uint64_t *info1, uint64_t *info2)
{
        *info1 = vcpu->exitintinfo;
        *info2 = vcpu_exception_intinfo(vcpu);
        return (0);
}

int
vm_inject_exception(struct vcpu *vcpu, int vector, int errcode_valid,
    uint32_t errcode, int restart_instruction)
{
        uint64_t regval;
        int error __diagused;

        if (vector < 0 || vector >= 32)
                return (EINVAL);

        /*
         * A double fault exception should never be injected directly into
         * the guest. It is a derived exception that results from specific
         * combinations of nested faults.
         */
        if (vector == IDT_DF)
                return (EINVAL);

        if (vcpu->exception_pending) {
                VMM_CTR2(vcpu, "Unable to inject exception %d due to "
                    "pending exception %d", vector, vcpu->exc_vector);
                return (EBUSY);
        }

        if (errcode_valid) {
                /*
                 * Exceptions don't deliver an error code in real mode.
                 */
                error = vm_get_register(vcpu, VM_REG_GUEST_CR0, &regval);
                KASSERT(!error, ("%s: error %d getting CR0", __func__, error));
                if (!(regval & CR0_PE))
                        errcode_valid = 0;
        }

        /*
         * From section 26.6.1 "Interruptibility State" in Intel SDM:
         *
         * Event blocking by "STI" or "MOV SS" is cleared after guest executes
         * one instruction or incurs an exception.
         */
        error = vm_set_register(vcpu, VM_REG_GUEST_INTR_SHADOW, 0);
        KASSERT(error == 0, ("%s: error %d clearing interrupt shadow",
            __func__, error));

        if (restart_instruction)
                vm_restart_instruction(vcpu);

        vcpu->exception_pending = 1;
        vcpu->exc_vector = vector;
        vcpu->exc_errcode = errcode;
        vcpu->exc_errcode_valid = errcode_valid;
        VMM_CTR1(vcpu, "Exception %d pending", vector);
        return (0);
}

void
vm_inject_fault(struct vcpu *vcpu, int vector, int errcode_valid, int errcode)
{
        int error __diagused, restart_instruction;

        restart_instruction = 1;

        error = vm_inject_exception(vcpu, vector, errcode_valid,
            errcode, restart_instruction);
        KASSERT(error == 0, ("vm_inject_exception error %d", error));
}

void
vm_inject_pf(struct vcpu *vcpu, int error_code, uint64_t cr2)
{
        int error __diagused;

        VMM_CTR2(vcpu, "Injecting page fault: error_code %#x, cr2 %#lx",
            error_code, cr2);

        error = vm_set_register(vcpu, VM_REG_GUEST_CR2, cr2);
        KASSERT(error == 0, ("vm_set_register(cr2) error %d", error));

        vm_inject_fault(vcpu, IDT_PF, 1, error_code);
}

static VMM_STAT(VCPU_NMI_COUNT, "number of NMIs delivered to vcpu");

int
vm_inject_nmi(struct vcpu *vcpu)
{

        vcpu->nmi_pending = 1;
        vcpu_notify_event(vcpu);
        return (0);
}

int
vm_nmi_pending(struct vcpu *vcpu)
{
        return (vcpu->nmi_pending);
}

void
vm_nmi_clear(struct vcpu *vcpu)
{
        if (vcpu->nmi_pending == 0)
                panic("vm_nmi_clear: inconsistent nmi_pending state");

        vcpu->nmi_pending = 0;
        vmm_stat_incr(vcpu, VCPU_NMI_COUNT, 1);
}

static VMM_STAT(VCPU_EXTINT_COUNT, "number of ExtINTs delivered to vcpu");

int
vm_inject_extint(struct vcpu *vcpu)
{

        vcpu->extint_pending = 1;
        vcpu_notify_event(vcpu);
        return (0);
}

int
vm_extint_pending(struct vcpu *vcpu)
{
        return (vcpu->extint_pending);
}

void
vm_extint_clear(struct vcpu *vcpu)
{
        if (vcpu->extint_pending == 0)
                panic("vm_extint_clear: inconsistent extint_pending state");

        vcpu->extint_pending = 0;
        vmm_stat_incr(vcpu, VCPU_EXTINT_COUNT, 1);
}

int
vm_get_capability(struct vcpu *vcpu, int type, int *retval)
{
        if (type < 0 || type >= VM_CAP_MAX)
                return (EINVAL);

        return (vmmops_getcap(vcpu->cookie, type, retval));
}

int
vm_set_capability(struct vcpu *vcpu, int type, int val)
{
        if (type < 0 || type >= VM_CAP_MAX)
                return (EINVAL);

        return (vmmops_setcap(vcpu->cookie, type, val));
}

struct vlapic *
vm_lapic(struct vcpu *vcpu)
{
        return (vcpu->vlapic);
}

struct vioapic *
vm_ioapic(struct vm *vm)
{

        return (vm->vioapic);
}

struct vhpet *
vm_hpet(struct vm *vm)
{

        return (vm->vhpet);
}

bool
vmm_is_pptdev(int bus, int slot, int func)
{
        int b, f, i, n, s;
        char *val, *cp, *cp2;
        bool found;

        /*
         * XXX
         * The length of an environment variable is limited to 128 bytes which
         * puts an upper limit on the number of passthru devices that may be
         * specified using a single environment variable.
         *
         * Work around this by scanning multiple environment variable
         * names instead of a single one - yuck!
         */
        const char *names[] = { "pptdevs", "pptdevs2", "pptdevs3", NULL };

        /* set pptdevs="1/2/3 4/5/6 7/8/9 10/11/12" */
        found = false;
        for (i = 0; names[i] != NULL && !found; i++) {
                cp = val = kern_getenv(names[i]);
                while (cp != NULL && *cp != '\0') {
                        if ((cp2 = strchr(cp, ' ')) != NULL)
                                *cp2 = '\0';

                        n = sscanf(cp, "%d/%d/%d", &b, &s, &f);
                        if (n == 3 && bus == b && slot == s && func == f) {
                                found = true;
                                break;
                        }

                        if (cp2 != NULL)
                                *cp2++ = ' ';

                        cp = cp2;
                }
                freeenv(val);
        }
        return (found);
}

void *
vm_iommu_domain(struct vm *vm)
{

        return (vm->iommu);
}

/*
 * Returns the subset of vCPUs in tostart that are awaiting startup.
 * These vCPUs are also marked as no longer awaiting startup.
 */
cpuset_t
vm_start_cpus(struct vm *vm, const cpuset_t *tostart)
{
        cpuset_t set;

        mtx_lock(&vm->rendezvous_mtx);
        CPU_AND(&set, &vm->startup_cpus, tostart);
        CPU_ANDNOT(&vm->startup_cpus, &vm->startup_cpus, &set);
        mtx_unlock(&vm->rendezvous_mtx);
        return (set);
}

void
vm_await_start(struct vm *vm, const cpuset_t *waiting)
{
        mtx_lock(&vm->rendezvous_mtx);
        CPU_OR(&vm->startup_cpus, &vm->startup_cpus, waiting);
        mtx_unlock(&vm->rendezvous_mtx);
}

int
vm_get_x2apic_state(struct vcpu *vcpu, enum x2apic_state *state)
{
        *state = vcpu->x2apic_state;

        return (0);
}

int
vm_set_x2apic_state(struct vcpu *vcpu, enum x2apic_state state)
{
        if (state >= X2APIC_STATE_LAST)
                return (EINVAL);

        vcpu->x2apic_state = state;

        vlapic_set_x2apic_state(vcpu, state);

        return (0);
}

void
vcpu_notify_lapic(struct vcpu *vcpu)
{
        vcpu_lock(vcpu);
        if (vcpu->state == VCPU_RUNNING && vcpu->hostcpu != curcpu)
                vlapic_post_intr(vcpu->vlapic, vcpu->hostcpu, vmm_ipinum);
        else
                vcpu_notify_event_locked(vcpu);
        vcpu_unlock(vcpu);
}

int
vm_apicid2vcpuid(struct vm *vm, int apicid)
{
        /*
         * XXX apic id is assumed to be numerically identical to vcpu id
         */
        return (apicid);
}

int
vm_smp_rendezvous(struct vcpu *vcpu, cpuset_t dest,
    vm_rendezvous_func_t func, void *arg)
{
        struct vm *vm = vcpu->vm;
        int error, i;

        /*
         * Enforce that this function is called without any locks
         */
        WITNESS_WARN(WARN_PANIC, NULL, "vm_smp_rendezvous");

restart:
        mtx_lock(&vm->rendezvous_mtx);
        if (vm->rendezvous_func != NULL) {
                /*
                 * If a rendezvous is already in progress then we need to
                 * call the rendezvous handler in case this 'vcpu' is one
                 * of the targets of the rendezvous.
                 */
                VMM_CTR0(vcpu, "Rendezvous already in progress");
                mtx_unlock(&vm->rendezvous_mtx);
                error = vm_handle_rendezvous(vcpu);
                if (error != 0)
                        return (error);
                goto restart;
        }
        KASSERT(vm->rendezvous_func == NULL, ("vm_smp_rendezvous: previous "
            "rendezvous is still in progress"));

        VMM_CTR0(vcpu, "Initiating rendezvous");
        vm->rendezvous_req_cpus = dest;
        CPU_ZERO(&vm->rendezvous_done_cpus);
        vm->rendezvous_arg = arg;
        vm->rendezvous_func = func;
        mtx_unlock(&vm->rendezvous_mtx);

        /*
         * Wake up any sleeping vcpus and trigger a VM-exit in any running
         * vcpus so they handle the rendezvous as soon as possible.
         */
        for (i = 0; i < vm->maxcpus; i++) {
                if (CPU_ISSET(i, &dest))
                        vcpu_notify_event(vm_vcpu(vm, i));
        }

        return (vm_handle_rendezvous(vcpu));
}

struct vatpic *
vm_atpic(struct vm *vm)
{
        return (vm->vatpic);
}

struct vatpit *
vm_atpit(struct vm *vm)
{
        return (vm->vatpit);
}

struct vpmtmr *
vm_pmtmr(struct vm *vm)
{

        return (vm->vpmtmr);
}

struct vrtc *
vm_rtc(struct vm *vm)
{

        return (vm->vrtc);
}

enum vm_reg_name
vm_segment_name(int seg)
{
        static enum vm_reg_name seg_names[] = {
                VM_REG_GUEST_ES,
                VM_REG_GUEST_CS,
                VM_REG_GUEST_SS,
                VM_REG_GUEST_DS,
                VM_REG_GUEST_FS,
                VM_REG_GUEST_GS
        };

        KASSERT(seg >= 0 && seg < nitems(seg_names),
            ("%s: invalid segment encoding %d", __func__, seg));
        return (seg_names[seg]);
}

void
vm_copy_teardown(struct vm_copyinfo *copyinfo, int num_copyinfo)
{
        int idx;

        for (idx = 0; idx < num_copyinfo; idx++) {
                if (copyinfo[idx].cookie != NULL)
                        vm_gpa_release(copyinfo[idx].cookie);
        }
        bzero(copyinfo, num_copyinfo * sizeof(struct vm_copyinfo));
}

int
vm_copy_setup(struct vcpu *vcpu, struct vm_guest_paging *paging,
    uint64_t gla, size_t len, int prot, struct vm_copyinfo *copyinfo,
    int num_copyinfo, int *fault)
{
        int error, idx, nused;
        size_t n, off, remaining;
        void *hva, *cookie;
        uint64_t gpa;

        bzero(copyinfo, sizeof(struct vm_copyinfo) * num_copyinfo);

        nused = 0;
        remaining = len;
        while (remaining > 0) {
                if (nused >= num_copyinfo)
                        return (EFAULT);
                error = vm_gla2gpa(vcpu, paging, gla, prot, &gpa, fault);
                if (error || *fault)
                        return (error);
                off = gpa & PAGE_MASK;
                n = min(remaining, PAGE_SIZE - off);
                copyinfo[nused].gpa = gpa;
                copyinfo[nused].len = n;
                remaining -= n;
                gla += n;
                nused++;
        }

        for (idx = 0; idx < nused; idx++) {
                hva = vm_gpa_hold(vcpu, copyinfo[idx].gpa,
                    copyinfo[idx].len, prot, &cookie);
                if (hva == NULL)
                        break;
                copyinfo[idx].hva = hva;
                copyinfo[idx].cookie = cookie;
        }

        if (idx != nused) {
                vm_copy_teardown(copyinfo, num_copyinfo);
                return (EFAULT);
        } else {
                *fault = 0;
                return (0);
        }
}

void
vm_copyin(struct vm_copyinfo *copyinfo, void *kaddr, size_t len)
{
        char *dst;
        int idx;

        dst = kaddr;
        idx = 0;
        while (len > 0) {
                bcopy(copyinfo[idx].hva, dst, copyinfo[idx].len);
                len -= copyinfo[idx].len;
                dst += copyinfo[idx].len;
                idx++;
        }
}

void
vm_copyout(const void *kaddr, struct vm_copyinfo *copyinfo, size_t len)
{
        const char *src;
        int idx;

        src = kaddr;
        idx = 0;
        while (len > 0) {
                bcopy(src, copyinfo[idx].hva, copyinfo[idx].len);
                len -= copyinfo[idx].len;
                src += copyinfo[idx].len;
                idx++;
        }
}

/*
 * Return the amount of in-use and wired memory for the VM. Since
 * these are global stats, only return the values with for vCPU 0
 */
VMM_STAT_DECLARE(VMM_MEM_RESIDENT);
VMM_STAT_DECLARE(VMM_MEM_WIRED);

static void
vm_get_rescnt(struct vcpu *vcpu, struct vmm_stat_type *stat)
{

        if (vcpu->vcpuid == 0) {
                vmm_stat_set(vcpu, VMM_MEM_RESIDENT, PAGE_SIZE *
                    vmspace_resident_count(vm_vmspace(vcpu->vm)));
        }
}

static void
vm_get_wiredcnt(struct vcpu *vcpu, struct vmm_stat_type *stat)
{

        if (vcpu->vcpuid == 0) {
                vmm_stat_set(vcpu, VMM_MEM_WIRED, PAGE_SIZE *
                    pmap_wired_count(vmspace_pmap(vm_vmspace(vcpu->vm))));
        }
}

VMM_STAT_FUNC(VMM_MEM_RESIDENT, "Resident memory", vm_get_rescnt);
VMM_STAT_FUNC(VMM_MEM_WIRED, "Wired memory", vm_get_wiredcnt);

#ifdef BHYVE_SNAPSHOT
static int
vm_snapshot_vcpus(struct vm *vm, struct vm_snapshot_meta *meta)
{
        uint64_t tsc, now;
        int ret;
        struct vcpu *vcpu;
        uint16_t i, maxcpus;

        now = rdtsc();
        maxcpus = vm_get_maxcpus(vm);
        for (i = 0; i < maxcpus; i++) {
                vcpu = vm->vcpu[i];
                if (vcpu == NULL)
                        continue;

                SNAPSHOT_VAR_OR_LEAVE(vcpu->x2apic_state, meta, ret, done);
                SNAPSHOT_VAR_OR_LEAVE(vcpu->exitintinfo, meta, ret, done);
                SNAPSHOT_VAR_OR_LEAVE(vcpu->exc_vector, meta, ret, done);
                SNAPSHOT_VAR_OR_LEAVE(vcpu->exc_errcode_valid, meta, ret, done);
                SNAPSHOT_VAR_OR_LEAVE(vcpu->exc_errcode, meta, ret, done);
                SNAPSHOT_VAR_OR_LEAVE(vcpu->guest_xcr0, meta, ret, done);
                SNAPSHOT_VAR_OR_LEAVE(vcpu->exitinfo, meta, ret, done);
                SNAPSHOT_VAR_OR_LEAVE(vcpu->nextrip, meta, ret, done);

                /*
                 * Save the absolute TSC value by adding now to tsc_offset.
                 *
                 * It will be turned turned back into an actual offset when the
                 * TSC restore function is called
                 */
                tsc = now + vcpu->tsc_offset;
                SNAPSHOT_VAR_OR_LEAVE(tsc, meta, ret, done);
                if (meta->op == VM_SNAPSHOT_RESTORE)
                        vcpu->tsc_offset = tsc;
        }

done:
        return (ret);
}

static int
vm_snapshot_vm(struct vm *vm, struct vm_snapshot_meta *meta)
{
        int ret;

        ret = vm_snapshot_vcpus(vm, meta);
        if (ret != 0)
                goto done;

        SNAPSHOT_VAR_OR_LEAVE(vm->startup_cpus, meta, ret, done);
done:
        return (ret);
}

static int
vm_snapshot_vcpu(struct vm *vm, struct vm_snapshot_meta *meta)
{
        int error;
        struct vcpu *vcpu;
        uint16_t i, maxcpus;

        error = 0;

        maxcpus = vm_get_maxcpus(vm);
        for (i = 0; i < maxcpus; i++) {
                vcpu = vm->vcpu[i];
                if (vcpu == NULL)
                        continue;

                error = vmmops_vcpu_snapshot(vcpu->cookie, meta);
                if (error != 0) {
                        printf("%s: failed to snapshot vmcs/vmcb data for "
                               "vCPU: %d; error: %d\n", __func__, i, error);
                        goto done;
                }
        }

done:
        return (error);
}

/*
 * Save kernel-side structures to user-space for snapshotting.
 */
int
vm_snapshot_req(struct vm *vm, struct vm_snapshot_meta *meta)
{
        int ret = 0;

        switch (meta->dev_req) {
        case STRUCT_VMCX:
                ret = vm_snapshot_vcpu(vm, meta);
                break;
        case STRUCT_VM:
                ret = vm_snapshot_vm(vm, meta);
                break;
        case STRUCT_VIOAPIC:
                ret = vioapic_snapshot(vm_ioapic(vm), meta);
                break;
        case STRUCT_VLAPIC:
                ret = vlapic_snapshot(vm, meta);
                break;
        case STRUCT_VHPET:
                ret = vhpet_snapshot(vm_hpet(vm), meta);
                break;
        case STRUCT_VATPIC:
                ret = vatpic_snapshot(vm_atpic(vm), meta);
                break;
        case STRUCT_VATPIT:
                ret = vatpit_snapshot(vm_atpit(vm), meta);
                break;
        case STRUCT_VPMTMR:
                ret = vpmtmr_snapshot(vm_pmtmr(vm), meta);
                break;
        case STRUCT_VRTC:
                ret = vrtc_snapshot(vm_rtc(vm), meta);
                break;
        default:
                printf("%s: failed to find the requested type %#x\n",
                       __func__, meta->dev_req);
                ret = (EINVAL);
        }
        return (ret);
}

void
vm_set_tsc_offset(struct vcpu *vcpu, uint64_t offset)
{
        vcpu->tsc_offset = offset;
}

int
vm_restore_time(struct vm *vm)
{
        int error;
        uint64_t now;
        struct vcpu *vcpu;
        uint16_t i, maxcpus;

        now = rdtsc();

        error = vhpet_restore_time(vm_hpet(vm));
        if (error)
                return (error);

        maxcpus = vm_get_maxcpus(vm);
        for (i = 0; i < maxcpus; i++) {
                vcpu = vm->vcpu[i];
                if (vcpu == NULL)
                        continue;

                error = vmmops_restore_tsc(vcpu->cookie,
                    vcpu->tsc_offset - now);
                if (error)
                        return (error);
        }

        return (0);
}
#endif