Handle nested exceptions in bhyve.

[FreeBSD/FreeBSD.git] / sys / amd64 / vmm / vmm.c

/*-
 * 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.
 *
 * $FreeBSD$
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/module.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/systm.h>

#include <vm/vm.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_extern.h>
#include <vm/vm_param.h>

#include <machine/cpu.h>
#include <machine/vm.h>
#include <machine/pcb.h>
#include <machine/smp.h>
#include <x86/psl.h>
#include <x86/apicreg.h>
#include <machine/vmparam.h>

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

#include "vmm_ioport.h"
#include "vmm_ktr.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 "vmm_msr.h"
#include "vmm_ipi.h"
#include "vmm_stat.h"
#include "vmm_lapic.h"

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

struct vlapic;

/*
 * Initialization:
 * (a) allocated when vcpu is created
 * (i) initialized when vcpu is created and when it is reinitialized
 * (o) initialized the first time the vcpu is created
 * (x) initialized before use
 */
struct vcpu {
        struct mtx      mtx;            /* (o) protects 'state' and 'hostcpu' */
        enum vcpu_state state;          /* (o) vcpu state */
        int             hostcpu;        /* (o) vcpu's host cpu */
        struct vlapic   *vlapic;        /* (i) APIC device model */
        enum x2apic_state x2apic_state; /* (i) APIC mode */
        uint64_t        exitintinfo;    /* (i) events pending at VM exit */
        int             nmi_pending;    /* (i) NMI pending */
        int             extint_pending; /* (i) INTR pending */
        struct vm_exception exception;  /* (x) exception collateral */
        int     exception_pending;      /* (i) exception pending */
        struct savefpu  *guestfpu;      /* (a,i) guest fpu state */
        uint64_t        guest_xcr0;     /* (i) guest %xcr0 register */
        void            *stats;         /* (a,i) statistics */
        uint64_t guest_msrs[VMM_MSR_NUM]; /* (i) emulated MSRs */
        struct vm_exit  exitinfo;       /* (x) exit reason and collateral */
};

#define vcpu_lock_initialized(v) mtx_initialized(&((v)->mtx))
#define vcpu_lock_init(v)       mtx_init(&((v)->mtx), "vcpu lock", 0, MTX_SPIN)
#define vcpu_lock(v)            mtx_lock_spin(&((v)->mtx))
#define vcpu_unlock(v)          mtx_unlock_spin(&((v)->mtx))
#define vcpu_assert_locked(v)   mtx_assert(&((v)->mtx), MA_OWNED)

struct mem_seg {
        vm_paddr_t      gpa;
        size_t          len;
        boolean_t       wired;
        vm_object_t     object;
};
#define VM_MAX_MEMORY_SEGMENTS  2

/*
 * Initialization:
 * (o) initialized the first time the VM is created
 * (i) initialized when VM is created and when it is reinitialized
 * (x) initialized before use
 */
struct vm {
        void            *cookie;                /* (i) cpu-specific data */
        void            *iommu;                 /* (x) iommu-specific data */
        struct vhpet    *vhpet;                 /* (i) virtual HPET */
        struct vioapic  *vioapic;               /* (i) virtual ioapic */
        struct vatpic   *vatpic;                /* (i) virtual atpic */
        struct vatpit   *vatpit;                /* (i) virtual atpit */
        volatile cpuset_t active_cpus;          /* (i) active vcpus */
        int             suspend;                /* (i) stop VM execution */
        volatile cpuset_t suspended_cpus;       /* (i) suspended vcpus */
        volatile cpuset_t halted_cpus;          /* (x) cpus in a hard halt */
        cpuset_t        rendezvous_req_cpus;    /* (x) rendezvous requested */
        cpuset_t        rendezvous_done_cpus;   /* (x) rendezvous finished */
        void            *rendezvous_arg;        /* (x) rendezvous func/arg */
        vm_rendezvous_func_t rendezvous_func;
        struct mtx      rendezvous_mtx;         /* (o) rendezvous lock */
        int             num_mem_segs;           /* (o) guest memory segments */
        struct mem_seg  mem_segs[VM_MAX_MEMORY_SEGMENTS];
        struct vmspace  *vmspace;               /* (o) guest's address space */
        char            name[VM_MAX_NAMELEN];   /* (o) virtual machine name */
        struct vcpu     vcpu[VM_MAXCPU];        /* (i) guest vcpus */
};

static int vmm_initialized;

static struct vmm_ops *ops;
#define VMM_INIT(num)   (ops != NULL ? (*ops->init)(num) : 0)
#define VMM_CLEANUP()   (ops != NULL ? (*ops->cleanup)() : 0)
#define VMM_RESUME()    (ops != NULL ? (*ops->resume)() : 0)

#define VMINIT(vm, pmap) (ops != NULL ? (*ops->vminit)(vm, pmap): NULL)
#define VMRUN(vmi, vcpu, rip, pmap, rptr, sptr) \
        (ops != NULL ? (*ops->vmrun)(vmi, vcpu, rip, pmap, rptr, sptr) : ENXIO)
#define VMCLEANUP(vmi)  (ops != NULL ? (*ops->vmcleanup)(vmi) : NULL)
#define VMSPACE_ALLOC(min, max) \
        (ops != NULL ? (*ops->vmspace_alloc)(min, max) : NULL)
#define VMSPACE_FREE(vmspace) \
        (ops != NULL ? (*ops->vmspace_free)(vmspace) : ENXIO)
#define VMGETREG(vmi, vcpu, num, retval)                \
        (ops != NULL ? (*ops->vmgetreg)(vmi, vcpu, num, retval) : ENXIO)
#define VMSETREG(vmi, vcpu, num, val)           \
        (ops != NULL ? (*ops->vmsetreg)(vmi, vcpu, num, val) : ENXIO)
#define VMGETDESC(vmi, vcpu, num, desc)         \
        (ops != NULL ? (*ops->vmgetdesc)(vmi, vcpu, num, desc) : ENXIO)
#define VMSETDESC(vmi, vcpu, num, desc)         \
        (ops != NULL ? (*ops->vmsetdesc)(vmi, vcpu, num, desc) : ENXIO)
#define VMGETCAP(vmi, vcpu, num, retval)        \
        (ops != NULL ? (*ops->vmgetcap)(vmi, vcpu, num, retval) : ENXIO)
#define VMSETCAP(vmi, vcpu, num, val)           \
        (ops != NULL ? (*ops->vmsetcap)(vmi, vcpu, num, val) : ENXIO)
#define VLAPIC_INIT(vmi, vcpu)                  \
        (ops != NULL ? (*ops->vlapic_init)(vmi, vcpu) : NULL)
#define VLAPIC_CLEANUP(vmi, vlapic)             \
        (ops != NULL ? (*ops->vlapic_cleanup)(vmi, vlapic) : NULL)

#define fpu_start_emulating()   load_cr0(rcr0() | CR0_TS)
#define fpu_stop_emulating()    clts()

static MALLOC_DEFINE(M_VM, "vm", "vm");
CTASSERT(VMM_MSR_NUM <= 64);    /* msr_mask can keep track of up to 64 msrs */

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

SYSCTL_NODE(_hw, OID_AUTO, vmm, CTLFLAG_RW, NULL, NULL);

/*
 * 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 vmm_ipinum;
SYSCTL_INT(_hw_vmm, OID_AUTO, ipinum, CTLFLAG_RD, &vmm_ipinum, 0,
    "IPI vector used for vcpu notifications");

static void
vcpu_cleanup(struct vm *vm, int i, bool destroy)
{
        struct vcpu *vcpu = &vm->vcpu[i];

        VLAPIC_CLEANUP(vm->cookie, vcpu->vlapic);
        if (destroy) {
                vmm_stat_free(vcpu->stats);     
                fpu_save_area_free(vcpu->guestfpu);
        }
}

static void
vcpu_init(struct vm *vm, int vcpu_id, bool create)
{
        struct vcpu *vcpu;

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

        if (create) {
                KASSERT(!vcpu_lock_initialized(vcpu), ("vcpu %d already "
                    "initialized", vcpu_id));
                vcpu_lock_init(vcpu);
                vcpu->state = VCPU_IDLE;
                vcpu->hostcpu = NOCPU;
                vcpu->guestfpu = fpu_save_area_alloc();
                vcpu->stats = vmm_stat_alloc();
        }

        vcpu->vlapic = VLAPIC_INIT(vm->cookie, vcpu_id);
        vm_set_x2apic_state(vm, vcpu_id, X2APIC_DISABLED);
        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);
        guest_msrs_init(vm, vcpu_id);
}

struct vm_exit *
vm_exitinfo(struct vm *vm, int cpuid)
{
        struct vcpu *vcpu;

        if (cpuid < 0 || cpuid >= VM_MAXCPU)
                panic("vm_exitinfo: invalid cpuid %d", cpuid);

        vcpu = &vm->vcpu[cpuid];

        return (&vcpu->exitinfo);
}

static void
vmm_resume(void)
{
        VMM_RESUME();
}

static int
vmm_init(void)
{
        int error;

        vmm_host_state_init();

        vmm_ipinum = vmm_ipi_alloc();
        if (vmm_ipinum == 0)
                vmm_ipinum = IPI_AST;

        error = vmm_mem_init();
        if (error)
                return (error);
        
        if (vmm_is_intel())
                ops = &vmm_ops_intel;
        else if (vmm_is_amd())
                ops = &vmm_ops_amd;
        else
                return (ENXIO);

        vmm_msr_init();
        vmm_resume_p = vmm_resume;

        return (VMM_INIT(vmm_ipinum));
}

static int
vmm_handler(module_t mod, int what, void *arg)
{
        int error;

        switch (what) {
        case MOD_LOAD:
                vmmdev_init();
                if (ppt_avail_devices() > 0)
                        iommu_init();
                error = vmm_init();
                if (error == 0)
                        vmm_initialized = 1;
                break;
        case MOD_UNLOAD:
                error = vmmdev_cleanup();
                if (error == 0) {
                        vmm_resume_p = NULL;
                        iommu_cleanup();
                        if (vmm_ipinum != IPI_AST)
                                vmm_ipi_free(vmm_ipinum);
                        error = VMM_CLEANUP();
                        /*
                         * Something bad happened - prevent new
                         * VMs from being created
                         */
                        if (error)
                                vmm_initialized = 0;
                }
                break;
        default:
                error = 0;
                break;
        }
        return (error);
}

static moduledata_t vmm_kmod = {
        "vmm",
        vmm_handler,
        NULL
};

/*
 * vmm initialization has the following dependencies:
 *
 * - iommu initialization must happen after the pci passthru driver has had
 *   a chance to attach to any passthru devices (after SI_SUB_CONFIGURE).
 *
 * - VT-x initialization requires smp_rendezvous() and therefore must happen
 *   after SMP is fully functional (after SI_SUB_SMP).
 */
DECLARE_MODULE(vmm, vmm_kmod, SI_SUB_SMP + 1, SI_ORDER_ANY);
MODULE_VERSION(vmm, 1);

static void
vm_init(struct vm *vm, bool create)
{
        int i;

        vm->cookie = VMINIT(vm, vmspace_pmap(vm->vmspace));
        vm->iommu = NULL;
        vm->vioapic = vioapic_init(vm);
        vm->vhpet = vhpet_init(vm);
        vm->vatpic = vatpic_init(vm);
        vm->vatpit = vatpit_init(vm);

        CPU_ZERO(&vm->active_cpus);

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

        for (i = 0; i < VM_MAXCPU; i++)
                vcpu_init(vm, i, create);
}

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

        /*
         * If vmm.ko could not be successfully initialized then don't attempt
         * to create the virtual machine.
         */
        if (!vmm_initialized)
                return (ENXIO);

        if (name == NULL || strlen(name) >= VM_MAX_NAMELEN)
                return (EINVAL);

        vmspace = VMSPACE_ALLOC(VM_MIN_ADDRESS, VM_MAXUSER_ADDRESS);
        if (vmspace == NULL)
                return (ENOMEM);

        vm = malloc(sizeof(struct vm), M_VM, M_WAITOK | M_ZERO);
        strcpy(vm->name, name);
        vm->num_mem_segs = 0;
        vm->vmspace = vmspace;
        mtx_init(&vm->rendezvous_mtx, "vm rendezvous lock", 0, MTX_DEF);

        vm_init(vm, true);

        *retvm = vm;
        return (0);
}

static void
vm_free_mem_seg(struct vm *vm, struct mem_seg *seg)
{

        if (seg->object != NULL)
                vmm_mem_free(vm->vmspace, seg->gpa, seg->len);

        bzero(seg, sizeof(*seg));
}

static void
vm_cleanup(struct vm *vm, bool destroy)
{
        int i;

        ppt_unassign_all(vm);

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

        vatpit_cleanup(vm->vatpit);
        vhpet_cleanup(vm->vhpet);
        vatpic_cleanup(vm->vatpic);
        vioapic_cleanup(vm->vioapic);

        for (i = 0; i < VM_MAXCPU; i++)
                vcpu_cleanup(vm, i, destroy);

        VMCLEANUP(vm->cookie);

        if (destroy) {
                for (i = 0; i < vm->num_mem_segs; i++)
                        vm_free_mem_seg(vm, &vm->mem_segs[i]);

                vm->num_mem_segs = 0;

                VMSPACE_FREE(vm->vmspace);
                vm->vmspace = NULL;
        }
}

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

int
vm_reinit(struct vm *vm)
{
        int error;

        /*
         * A virtual machine can be reset only if all vcpus are suspended.
         */
        if (CPU_CMP(&vm->suspended_cpus, &vm->active_cpus) == 0) {
                vm_cleanup(vm, false);
                vm_init(vm, false);
                error = 0;
        } else {
                error = EBUSY;
        }

        return (error);
}

const char *
vm_name(struct vm *vm)
{
        return (vm->name);
}

int
vm_map_mmio(struct vm *vm, vm_paddr_t gpa, size_t len, vm_paddr_t hpa)
{
        vm_object_t obj;

        if ((obj = vmm_mmio_alloc(vm->vmspace, gpa, len, hpa)) == NULL)
                return (ENOMEM);
        else
                return (0);
}

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

        vmm_mmio_free(vm->vmspace, gpa, len);
        return (0);
}

boolean_t
vm_mem_allocated(struct vm *vm, vm_paddr_t gpa)
{
        int i;
        vm_paddr_t gpabase, gpalimit;

        for (i = 0; i < vm->num_mem_segs; i++) {
                gpabase = vm->mem_segs[i].gpa;
                gpalimit = gpabase + vm->mem_segs[i].len;
                if (gpa >= gpabase && gpa < gpalimit)
                        return (TRUE);          /* 'gpa' is regular memory */
        }

        if (ppt_is_mmio(vm, gpa))
                return (TRUE);                  /* 'gpa' is pci passthru mmio */

        return (FALSE);
}

int
vm_malloc(struct vm *vm, vm_paddr_t gpa, size_t len)
{
        int available, allocated;
        struct mem_seg *seg;
        vm_object_t object;
        vm_paddr_t g;

        if ((gpa & PAGE_MASK) || (len & PAGE_MASK) || len == 0)
                return (EINVAL);
        
        available = allocated = 0;
        g = gpa;
        while (g < gpa + len) {
                if (vm_mem_allocated(vm, g))
                        allocated++;
                else
                        available++;

                g += PAGE_SIZE;
        }

        /*
         * If there are some allocated and some available pages in the address
         * range then it is an error.
         */
        if (allocated && available)
                return (EINVAL);

        /*
         * If the entire address range being requested has already been
         * allocated then there isn't anything more to do.
         */
        if (allocated && available == 0)
                return (0);

        if (vm->num_mem_segs >= VM_MAX_MEMORY_SEGMENTS)
                return (E2BIG);

        seg = &vm->mem_segs[vm->num_mem_segs];

        if ((object = vmm_mem_alloc(vm->vmspace, gpa, len)) == NULL)
                return (ENOMEM);

        seg->gpa = gpa;
        seg->len = len;
        seg->object = object;
        seg->wired = FALSE;

        vm->num_mem_segs++;

        return (0);
}

static void
vm_gpa_unwire(struct vm *vm)
{
        int i, rv;
        struct mem_seg *seg;

        for (i = 0; i < vm->num_mem_segs; i++) {
                seg = &vm->mem_segs[i];
                if (!seg->wired)
                        continue;

                rv = vm_map_unwire(&vm->vmspace->vm_map,
                                   seg->gpa, seg->gpa + seg->len,
                                   VM_MAP_WIRE_USER | VM_MAP_WIRE_NOHOLES);
                KASSERT(rv == KERN_SUCCESS, ("vm(%s) memory segment "
                    "%#lx/%ld could not be unwired: %d",
                    vm_name(vm), seg->gpa, seg->len, rv));

                seg->wired = FALSE;
        }
}

static int
vm_gpa_wire(struct vm *vm)
{
        int i, rv;
        struct mem_seg *seg;

        for (i = 0; i < vm->num_mem_segs; i++) {
                seg = &vm->mem_segs[i];
                if (seg->wired)
                        continue;

                /* XXX rlimits? */
                rv = vm_map_wire(&vm->vmspace->vm_map,
                                 seg->gpa, seg->gpa + seg->len,
                                 VM_MAP_WIRE_USER | VM_MAP_WIRE_NOHOLES);
                if (rv != KERN_SUCCESS)
                        break;

                seg->wired = TRUE;
        }

        if (i < vm->num_mem_segs) {
                /*
                 * Undo the wiring before returning an error.
                 */
                vm_gpa_unwire(vm);
                return (EAGAIN);
        }

        return (0);
}

static void
vm_iommu_modify(struct vm *vm, boolean_t map)
{
        int i, sz;
        vm_paddr_t gpa, hpa;
        struct mem_seg *seg;
        void *vp, *cookie, *host_domain;

        sz = PAGE_SIZE;
        host_domain = iommu_host_domain();

        for (i = 0; i < vm->num_mem_segs; i++) {
                seg = &vm->mem_segs[i];
                KASSERT(seg->wired, ("vm(%s) memory segment %#lx/%ld not wired",
                    vm_name(vm), seg->gpa, seg->len));

                gpa = seg->gpa;
                while (gpa < seg->gpa + seg->len) {
                        vp = vm_gpa_hold(vm, gpa, PAGE_SIZE, VM_PROT_WRITE,
                                         &cookie);
                        KASSERT(vp != NULL, ("vm(%s) could not map gpa %#lx",
                            vm_name(vm), gpa));

                        vm_gpa_release(cookie);

                        hpa = DMAP_TO_PHYS((uintptr_t)vp);
                        if (map) {
                                iommu_create_mapping(vm->iommu, gpa, hpa, sz);
                                iommu_remove_mapping(host_domain, hpa, sz);
                        } else {
                                iommu_remove_mapping(vm->iommu, gpa, sz);
                                iommu_create_mapping(host_domain, hpa, hpa, sz);
                        }

                        gpa += PAGE_SIZE;
                }
        }

        /*
         * Invalidate the cached translations associated with the domain
         * from which pages were removed.
         */
        if (map)
                iommu_invalidate_tlb(host_domain);
        else
                iommu_invalidate_tlb(vm->iommu);
}

#define vm_iommu_unmap(vm)      vm_iommu_modify((vm), FALSE)
#define vm_iommu_map(vm)        vm_iommu_modify((vm), TRUE)

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) {
                vm_iommu_unmap(vm);
                vm_gpa_unwire(vm);
        }
        return (0);
}

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

        /*
         * Virtual machines with pci passthru devices get special treatment:
         * - the guest physical memory is wired
         * - the iommu is programmed to do the 'gpa' to 'hpa' translation
         *
         * We need to do this before the first pci passthru device is attached.
         */
        if (ppt_assigned_devices(vm) == 0) {
                KASSERT(vm->iommu == NULL,
                    ("vm_assign_pptdev: iommu must be NULL"));
                maxaddr = vmm_mem_maxaddr();
                vm->iommu = iommu_create_domain(maxaddr);

                error = vm_gpa_wire(vm);
                if (error)
                        return (error);

                vm_iommu_map(vm);
        }

        error = ppt_assign_device(vm, bus, slot, func);
        return (error);
}

void *
vm_gpa_hold(struct vm *vm, vm_paddr_t gpa, size_t len, int reqprot,
            void **cookie)
{
        int count, pageoff;
        vm_page_t m;

        pageoff = gpa & PAGE_MASK;
        if (len > PAGE_SIZE - pageoff)
                panic("vm_gpa_hold: invalid gpa/len: 0x%016lx/%lu", gpa, len);

        count = vm_fault_quick_hold_pages(&vm->vmspace->vm_map,
            trunc_page(gpa), PAGE_SIZE, reqprot, &m, 1);

        if (count == 1) {
                *cookie = m;
                return ((void *)(PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m)) + pageoff));
        } else {
                *cookie = NULL;
                return (NULL);
        }
}

void
vm_gpa_release(void *cookie)
{
        vm_page_t m = cookie;

        vm_page_lock(m);
        vm_page_unhold(m);
        vm_page_unlock(m);
}

int
vm_gpabase2memseg(struct vm *vm, vm_paddr_t gpabase,
                  struct vm_memory_segment *seg)
{
        int i;

        for (i = 0; i < vm->num_mem_segs; i++) {
                if (gpabase == vm->mem_segs[i].gpa) {
                        seg->gpa = vm->mem_segs[i].gpa;
                        seg->len = vm->mem_segs[i].len;
                        seg->wired = vm->mem_segs[i].wired;
                        return (0);
                }
        }
        return (-1);
}

int
vm_get_memobj(struct vm *vm, vm_paddr_t gpa, size_t len,
              vm_offset_t *offset, struct vm_object **object)
{
        int i;
        size_t seg_len;
        vm_paddr_t seg_gpa;
        vm_object_t seg_obj;

        for (i = 0; i < vm->num_mem_segs; i++) {
                if ((seg_obj = vm->mem_segs[i].object) == NULL)
                        continue;

                seg_gpa = vm->mem_segs[i].gpa;
                seg_len = vm->mem_segs[i].len;

                if (gpa >= seg_gpa && gpa < seg_gpa + seg_len) {
                        *offset = gpa - seg_gpa;
                        *object = seg_obj;
                        vm_object_reference(seg_obj);
                        return (0);
                }
        }

        return (EINVAL);
}

int
vm_get_register(struct vm *vm, int vcpu, int reg, uint64_t *retval)
{

        if (vcpu < 0 || vcpu >= VM_MAXCPU)
                return (EINVAL);

        if (reg >= VM_REG_LAST)
                return (EINVAL);

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

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

        if (vcpu < 0 || vcpu >= VM_MAXCPU)
                return (EINVAL);

        if (reg >= VM_REG_LAST)
                return (EINVAL);

        return (VMSETREG(vm->cookie, vcpu, reg, val));
}

static boolean_t
is_descriptor_table(int reg)
{

        switch (reg) {
        case VM_REG_GUEST_IDTR:
        case VM_REG_GUEST_GDTR:
                return (TRUE);
        default:
                return (FALSE);
        }
}

static boolean_t
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 vm *vm, int vcpu, int reg,
                struct seg_desc *desc)
{

        if (vcpu < 0 || vcpu >= VM_MAXCPU)
                return (EINVAL);

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

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

int
vm_set_seg_desc(struct vm *vm, int vcpu, int reg,
                struct seg_desc *desc)
{
        if (vcpu < 0 || vcpu >= VM_MAXCPU)
                return (EINVAL);

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

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

static void
restore_guest_fpustate(struct vcpu *vcpu)
{

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

        /* restore guest FPU state */
        fpu_stop_emulating();
        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 turn on emulation
         * to trap any access to the FPU by the host.
         */
        fpu_start_emulating();
}

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_stop_emulating();
        fpusave(vcpu->guestfpu);
        fpu_start_emulating();
}

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

static int
vcpu_set_state_locked(struct vcpu *vcpu, enum vcpu_state newstate,
    bool from_idle)
{
        int error;

        vcpu_assert_locked(vcpu);

        /*
         * State transitions from the vmmdev_ioctl() must always begin from
         * the VCPU_IDLE state. This guarantees that there is only a single
         * ioctl() operating on a vcpu at any point.
         */
        if (from_idle) {
                while (vcpu->state != VCPU_IDLE)
                        msleep_spin(&vcpu->state, &vcpu->mtx, "vmstat", hz);
        } else {
                KASSERT(vcpu->state != VCPU_IDLE, ("invalid transition from "
                    "vcpu idle state"));
        }

        if (vcpu->state == VCPU_RUNNING) {
                KASSERT(vcpu->hostcpu == curcpu, ("curcpu %d and hostcpu %d "
                    "mismatch for running vcpu", curcpu, vcpu->hostcpu));
        } else {
                KASSERT(vcpu->hostcpu == NOCPU, ("Invalid hostcpu %d for a "
                    "vcpu that is not running", vcpu->hostcpu));
        }

        /*
         * The following state transitions are allowed:
         * IDLE -> FROZEN -> IDLE
         * FROZEN -> RUNNING -> FROZEN
         * FROZEN -> SLEEPING -> FROZEN
         */
        switch (vcpu->state) {
        case VCPU_IDLE:
        case VCPU_RUNNING:
        case VCPU_SLEEPING:
                error = (newstate != VCPU_FROZEN);
                break;
        case VCPU_FROZEN:
                error = (newstate == VCPU_FROZEN);
                break;
        default:
                error = 1;
                break;
        }

        if (error)
                return (EBUSY);

        vcpu->state = newstate;
        if (newstate == VCPU_RUNNING)
                vcpu->hostcpu = curcpu;
        else
                vcpu->hostcpu = NOCPU;

        if (newstate == VCPU_IDLE)
                wakeup(&vcpu->state);

        return (0);
}

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

        if ((error = vcpu_set_state(vm, vcpuid, 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);
}

static void
vm_set_rendezvous_func(struct vm *vm, vm_rendezvous_func_t func)
{

        KASSERT(mtx_owned(&vm->rendezvous_mtx), ("rendezvous_mtx not locked"));

        /*
         * Update 'rendezvous_func' and execute a write memory barrier to
         * ensure that it is visible across all host cpus. This is not needed
         * for correctness but it does ensure that all the vcpus will notice
         * that the rendezvous is requested immediately.
         */
        vm->rendezvous_func = func;
        wmb();
}

#define RENDEZVOUS_CTR0(vm, vcpuid, fmt)                                \
        do {                                                            \
                if (vcpuid >= 0)                                        \
                        VCPU_CTR0(vm, vcpuid, fmt);                     \
                else                                                    \
                        VM_CTR0(vm, fmt);                               \
        } while (0)

static void
vm_handle_rendezvous(struct vm *vm, int vcpuid)
{

        KASSERT(vcpuid == -1 || (vcpuid >= 0 && vcpuid < VM_MAXCPU),
            ("vm_handle_rendezvous: invalid vcpuid %d", vcpuid));

        mtx_lock(&vm->rendezvous_mtx);
        while (vm->rendezvous_func != NULL) {
                /* 'rendezvous_req_cpus' must be a subset of 'active_cpus' */
                CPU_AND(&vm->rendezvous_req_cpus, &vm->active_cpus);

                if (vcpuid != -1 &&
                    CPU_ISSET(vcpuid, &vm->rendezvous_req_cpus) &&
                    !CPU_ISSET(vcpuid, &vm->rendezvous_done_cpus)) {
                        VCPU_CTR0(vm, vcpuid, "Calling rendezvous func");
                        (*vm->rendezvous_func)(vm, vcpuid, vm->rendezvous_arg);
                        CPU_SET(vcpuid, &vm->rendezvous_done_cpus);
                }
                if (CPU_CMP(&vm->rendezvous_req_cpus,
                    &vm->rendezvous_done_cpus) == 0) {
                        VCPU_CTR0(vm, vcpuid, "Rendezvous completed");
                        vm_set_rendezvous_func(vm, NULL);
                        wakeup(&vm->rendezvous_func);
                        break;
                }
                RENDEZVOUS_CTR0(vm, vcpuid, "Wait for rendezvous completion");
                mtx_sleep(&vm->rendezvous_func, &vm->rendezvous_mtx, 0,
                    "vmrndv", 0);
        }
        mtx_unlock(&vm->rendezvous_mtx);
}

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

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

        vcpu = &vm->vcpu[vcpuid];
        vcpu_halted = 0;
        vm_halted = 0;

        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 VMRUN() and before it acquired the
                 * vcpu lock above.
                 */
                if (vm->rendezvous_func != NULL || vm->suspend)
                        break;
                if (vm_nmi_pending(vm, vcpuid))
                        break;
                if (!intr_disabled) {
                        if (vm_extint_pending(vm, vcpuid) ||
                            vlapic_pending_intr(vcpu->vlapic, NULL)) {
                                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";
                        VCPU_CTR0(vm, vcpuid, "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);
                msleep_spin(vcpu, &vcpu->mtx, wmesg, 0);
                vcpu_require_state_locked(vcpu, VCPU_FROZEN);
                vmm_stat_incr(vm, vcpuid, VCPU_IDLE_TICKS, ticks - t);
        }

        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 vm *vm, int vcpuid, bool *retu)
{
        int rv, ftype;
        struct vm_map *map;
        struct vcpu *vcpu;
        struct vm_exit *vme;

        vcpu = &vm->vcpu[vcpuid];
        vme = &vcpu->exitinfo;

        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),
                    vme->u.paging.gpa, ftype);
                if (rv == 0)
                        goto done;
        }

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

        VCPU_CTR3(vm, vcpuid, "vm_handle_paging rv = %d, gpa = %#lx, "
            "ftype = %d", rv, vme->u.paging.gpa, ftype);

        if (rv != KERN_SUCCESS)
                return (EFAULT);
done:
        /* restart execution at the faulting instruction */
        vme->inst_length = 0;

        return (0);
}

static int
vm_handle_inst_emul(struct vm *vm, int vcpuid, bool *retu)
{
        struct vie *vie;
        struct vcpu *vcpu;
        struct vm_exit *vme;
        uint64_t gla, gpa;
        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;

        vcpu = &vm->vcpu[vcpuid];
        vme = &vcpu->exitinfo;

        gla = vme->u.inst_emul.gla;
        gpa = vme->u.inst_emul.gpa;
        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;

        vie_init(vie);

        /* Fetch, decode and emulate the faulting instruction */
        error = vmm_fetch_instruction(vm, vcpuid, paging, vme->rip,
            vme->inst_length, vie);
        if (error == 1)
                return (0);             /* Resume guest to handle page fault */
        else if (error == -1)
                return (EFAULT);
        else if (error != 0)
                panic("%s: vmm_fetch_instruction error %d", __func__, error);

        if (vmm_decode_instruction(vm, vcpuid, gla, cpu_mode, cs_d, vie) != 0)
                return (EFAULT);

        /* 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(vm, vcpuid, gpa, vie, mread, mwrite,
            retu);

        return (error);
}

static int
vm_handle_suspend(struct vm *vm, int vcpuid, bool *retu)
{
        int i, done;
        struct vcpu *vcpu;

        done = 0;
        vcpu = &vm->vcpu[vcpuid];

        CPU_SET_ATOMIC(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 (1) {
                if (CPU_CMP(&vm->suspended_cpus, &vm->active_cpus) == 0) {
                        VCPU_CTR0(vm, vcpuid, "All vcpus suspended");
                        break;
                }

                if (vm->rendezvous_func == NULL) {
                        VCPU_CTR0(vm, vcpuid, "Sleeping during suspend");
                        vcpu_require_state_locked(vcpu, VCPU_SLEEPING);
                        msleep_spin(vcpu, &vcpu->mtx, "vmsusp", hz);
                        vcpu_require_state_locked(vcpu, VCPU_FROZEN);
                } else {
                        VCPU_CTR0(vm, vcpuid, "Rendezvous during suspend");
                        vcpu_unlock(vcpu);
                        vm_handle_rendezvous(vm, vcpuid);
                        vcpu_lock(vcpu);
                }
        }
        vcpu_unlock(vcpu);

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

        *retu = true;
        return (0);
}

int
vm_suspend(struct vm *vm, enum vm_suspend_how how)
{
        int i;

        if (how <= VM_SUSPEND_NONE || how >= VM_SUSPEND_LAST)
                return (EINVAL);

        if (atomic_cmpset_int(&vm->suspend, 0, how) == 0) {
                VM_CTR2(vm, "virtual machine already suspended %d/%d",
                    vm->suspend, how);
                return (EALREADY);
        }

        VM_CTR1(vm, "virtual machine successfully suspended %d", how);

        /*
         * Notify all active vcpus that they are now suspended.
         */
        for (i = 0; i < VM_MAXCPU; i++) {
                if (CPU_ISSET(i, &vm->active_cpus))
                        vcpu_notify_event(vm, i, false);
        }

        return (0);
}

void
vm_exit_suspended(struct vm *vm, int vcpuid, uint64_t rip)
{
        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(vm, vcpuid);
        vmexit->rip = rip;
        vmexit->inst_length = 0;
        vmexit->exitcode = VM_EXITCODE_SUSPENDED;
        vmexit->u.suspended.how = vm->suspend;
}

void
vm_exit_rendezvous(struct vm *vm, int vcpuid, uint64_t rip)
{
        struct vm_exit *vmexit;

        KASSERT(vm->rendezvous_func != NULL, ("rendezvous not in progress"));

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

void
vm_exit_astpending(struct vm *vm, int vcpuid, uint64_t rip)
{
        struct vm_exit *vmexit;

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

int
vm_run(struct vm *vm, struct vm_run *vmrun)
{
        int error, vcpuid;
        struct vcpu *vcpu;
        struct pcb *pcb;
        uint64_t tscval, rip;
        struct vm_exit *vme;
        bool retu, intr_disabled;
        pmap_t pmap;
        void *rptr, *sptr;

        vcpuid = vmrun->cpuid;

        if (vcpuid < 0 || vcpuid >= VM_MAXCPU)
                return (EINVAL);

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

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

        rptr = &vm->rendezvous_func;
        sptr = &vm->suspend;
        pmap = vmspace_pmap(vm->vmspace);
        vcpu = &vm->vcpu[vcpuid];
        vme = &vcpu->exitinfo;
        rip = vmrun->rip;
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_msrs(vm, vcpuid); 
        restore_guest_fpustate(vcpu);

        vcpu_require_state(vm, vcpuid, VCPU_RUNNING);
        error = VMRUN(vm->cookie, vcpuid, rip, pmap, rptr, sptr);
        vcpu_require_state(vm, vcpuid, VCPU_FROZEN);

        save_guest_fpustate(vcpu);
        restore_host_msrs(vm, vcpuid);

        vmm_stat_incr(vm, vcpuid, VCPU_TOTAL_RUNTIME, rdtsc() - tscval);

        critical_exit();

        if (error == 0) {
                retu = false;
                switch (vme->exitcode) {
                case VM_EXITCODE_SUSPENDED:
                        error = vm_handle_suspend(vm, vcpuid, &retu);
                        break;
                case VM_EXITCODE_IOAPIC_EOI:
                        vioapic_process_eoi(vm, vcpuid,
                            vme->u.ioapic_eoi.vector);
                        break;
                case VM_EXITCODE_RENDEZVOUS:
                        vm_handle_rendezvous(vm, vcpuid);
                        error = 0;
                        break;
                case VM_EXITCODE_HLT:
                        intr_disabled = ((vme->u.hlt.rflags & PSL_I) == 0);
                        error = vm_handle_hlt(vm, vcpuid, intr_disabled, &retu);
                        break;
                case VM_EXITCODE_PAGING:
                        error = vm_handle_paging(vm, vcpuid, &retu);
                        break;
                case VM_EXITCODE_INST_EMUL:
                        error = vm_handle_inst_emul(vm, vcpuid, &retu);
                        break;
                case VM_EXITCODE_INOUT:
                case VM_EXITCODE_INOUT_STR:
                        error = vm_handle_inout(vm, vcpuid, vme, &retu);
                        break;
                default:
                        retu = true;    /* handled in userland */
                        break;
                }
        }

        if (error == 0 && retu == false) {
                rip = vme->rip + vme->inst_length;
                goto restart;
        }

        /* copy the exit information */
        bcopy(vme, &vmrun->vm_exit, sizeof(struct vm_exit));
        return (error);
}

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

        if (vcpuid < 0 || vcpuid >= VM_MAXCPU)
                return (EINVAL);

        vcpu = &vm->vcpu[vcpuid];

        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;
        }
        VCPU_CTR2(vm, vcpuid, "%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 vm *vm, int vcpuid, 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) {
                VCPU_CTR2(vm, vcpuid, "triple fault: info1(%#lx), info2(%#lx)",
                    info1, info2);
                vm_suspend(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->exception.vector & 0xff;
                info |= VM_INTINFO_VALID | VM_INTINFO_HWEXCEPTION;
                if (vcpu->exception.error_code_valid) {
                        info |= VM_INTINFO_DEL_ERRCODE;
                        info |= (uint64_t)vcpu->exception.error_code << 32;
                }
        }
        return (info);
}

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

        KASSERT(vcpuid >= 0 && vcpuid < VM_MAXCPU, ("invalid vcpu %d", vcpuid));

        vcpu = &vm->vcpu[vcpuid];

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

        info2 = 0;
        if (vcpu->exception_pending) {
                info2 = vcpu_exception_intinfo(vcpu);
                vcpu->exception_pending = 0;
                VCPU_CTR2(vm, vcpuid, "Exception %d delivered: %#lx",
                    vcpu->exception.vector, info2);
        }

        if ((info1 & VM_INTINFO_VALID) && (info2 & VM_INTINFO_VALID)) {
                valid = nested_fault(vm, vcpuid, 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) {
                VCPU_CTR4(vm, vcpuid, "%s: info1(%#lx), info2(%#lx), "
                    "retinfo(%#lx)", __func__, info1, info2, *retinfo);
        }

        return (valid);
}

int
vm_get_intinfo(struct vm *vm, int vcpuid, uint64_t *info1, uint64_t *info2)
{
        struct vcpu *vcpu;

        if (vcpuid < 0 || vcpuid >= VM_MAXCPU)
                return (EINVAL);

        vcpu = &vm->vcpu[vcpuid];
        *info1 = vcpu->exitintinfo;
        *info2 = vcpu_exception_intinfo(vcpu);
        return (0);
}

int
vm_inject_exception(struct vm *vm, int vcpuid, struct vm_exception *exception)
{
        struct vcpu *vcpu;

        if (vcpuid < 0 || vcpuid >= VM_MAXCPU)
                return (EINVAL);

        if (exception->vector < 0 || exception->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 (exception->vector == IDT_DF)
                return (EINVAL);

        vcpu = &vm->vcpu[vcpuid];

        if (vcpu->exception_pending) {
                VCPU_CTR2(vm, vcpuid, "Unable to inject exception %d due to "
                    "pending exception %d", exception->vector,
                    vcpu->exception.vector);
                return (EBUSY);
        }

        vcpu->exception_pending = 1;
        vcpu->exception = *exception;
        VCPU_CTR1(vm, vcpuid, "Exception %d pending", exception->vector);
        return (0);
}

static void
vm_inject_fault(struct vm *vm, int vcpuid, struct vm_exception *exception)
{
        struct vm_exit *vmexit;
        int error;

        error = vm_inject_exception(vm, vcpuid, exception);
        KASSERT(error == 0, ("vm_inject_exception error %d", error));

        /*
         * A fault-like exception allows the instruction to be restarted
         * after the exception handler returns.
         *
         * By setting the inst_length to 0 we ensure that the instruction
         * pointer remains at the faulting instruction.
         */
        vmexit = vm_exitinfo(vm, vcpuid);
        vmexit->inst_length = 0;
}

void
vm_inject_pf(struct vm *vm, int vcpuid, int error_code, uint64_t cr2)
{
        struct vm_exception pf = {
                .vector = IDT_PF,
                .error_code_valid = 1,
                .error_code = error_code
        };
        int error;

        VCPU_CTR2(vm, vcpuid, "Injecting page fault: error_code %#x, cr2 %#lx",
            error_code, cr2);

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

        vm_inject_fault(vm, vcpuid, &pf);
}

void
vm_inject_gp(struct vm *vm, int vcpuid)
{
        struct vm_exception gpf = {
                .vector = IDT_GP,
                .error_code_valid = 1,
                .error_code = 0
        };

        vm_inject_fault(vm, vcpuid, &gpf);
}

void
vm_inject_ud(struct vm *vm, int vcpuid)
{
        struct vm_exception udf = {
                .vector = IDT_UD,
                .error_code_valid = 0
        };

        vm_inject_fault(vm, vcpuid, &udf);
}

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

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

        if (vcpuid < 0 || vcpuid >= VM_MAXCPU)
                return (EINVAL);

        vcpu = &vm->vcpu[vcpuid];

        vcpu->nmi_pending = 1;
        vcpu_notify_event(vm, vcpuid, false);
        return (0);
}

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

        if (vcpuid < 0 || vcpuid >= VM_MAXCPU)
                panic("vm_nmi_pending: invalid vcpuid %d", vcpuid);

        vcpu = &vm->vcpu[vcpuid];

        return (vcpu->nmi_pending);
}

void
vm_nmi_clear(struct vm *vm, int vcpuid)
{
        struct vcpu *vcpu;

        if (vcpuid < 0 || vcpuid >= VM_MAXCPU)
                panic("vm_nmi_pending: invalid vcpuid %d", vcpuid);

        vcpu = &vm->vcpu[vcpuid];

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

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

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

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

        if (vcpuid < 0 || vcpuid >= VM_MAXCPU)
                return (EINVAL);

        vcpu = &vm->vcpu[vcpuid];

        vcpu->extint_pending = 1;
        vcpu_notify_event(vm, vcpuid, false);
        return (0);
}

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

        if (vcpuid < 0 || vcpuid >= VM_MAXCPU)
                panic("vm_extint_pending: invalid vcpuid %d", vcpuid);

        vcpu = &vm->vcpu[vcpuid];

        return (vcpu->extint_pending);
}

void
vm_extint_clear(struct vm *vm, int vcpuid)
{
        struct vcpu *vcpu;

        if (vcpuid < 0 || vcpuid >= VM_MAXCPU)
                panic("vm_extint_pending: invalid vcpuid %d", vcpuid);

        vcpu = &vm->vcpu[vcpuid];

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

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

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

        if (type < 0 || type >= VM_CAP_MAX)
                return (EINVAL);

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

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

        if (type < 0 || type >= VM_CAP_MAX)
                return (EINVAL);

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

uint64_t *
vm_guest_msrs(struct vm *vm, int cpu)
{
        return (vm->vcpu[cpu].guest_msrs);
}

struct vlapic *
vm_lapic(struct vm *vm, int cpu)
{
        return (vm->vcpu[cpu].vlapic);
}

struct vioapic *
vm_ioapic(struct vm *vm)
{

        return (vm->vioapic);
}

struct vhpet *
vm_hpet(struct vm *vm)
{

        return (vm->vhpet);
}

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

        /*
         * 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 = 0;
        for (i = 0; names[i] != NULL && !found; i++) {
                cp = val = 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 = 1;
                                break;
                        }
                
                        if (cp2 != NULL)
                                *cp2++ = ' ';

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

void *
vm_iommu_domain(struct vm *vm)
{

        return (vm->iommu);
}

int
vcpu_set_state(struct vm *vm, int vcpuid, enum vcpu_state newstate,
    bool from_idle)
{
        int error;
        struct vcpu *vcpu;

        if (vcpuid < 0 || vcpuid >= VM_MAXCPU)
                panic("vm_set_run_state: invalid vcpuid %d", vcpuid);

        vcpu = &vm->vcpu[vcpuid];

        vcpu_lock(vcpu);
        error = vcpu_set_state_locked(vcpu, newstate, from_idle);
        vcpu_unlock(vcpu);

        return (error);
}

enum vcpu_state
vcpu_get_state(struct vm *vm, int vcpuid, int *hostcpu)
{
        struct vcpu *vcpu;
        enum vcpu_state state;

        if (vcpuid < 0 || vcpuid >= VM_MAXCPU)
                panic("vm_get_run_state: invalid vcpuid %d", vcpuid);

        vcpu = &vm->vcpu[vcpuid];

        vcpu_lock(vcpu);
        state = vcpu->state;
        if (hostcpu != NULL)
                *hostcpu = vcpu->hostcpu;
        vcpu_unlock(vcpu);

        return (state);
}

int
vm_activate_cpu(struct vm *vm, int vcpuid)
{

        if (vcpuid < 0 || vcpuid >= VM_MAXCPU)
                return (EINVAL);

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

        VCPU_CTR0(vm, vcpuid, "activated");
        CPU_SET_ATOMIC(vcpuid, &vm->active_cpus);
        return (0);
}

cpuset_t
vm_active_cpus(struct vm *vm)
{

        return (vm->active_cpus);
}

cpuset_t
vm_suspended_cpus(struct vm *vm)
{

        return (vm->suspended_cpus);
}

void *
vcpu_stats(struct vm *vm, int vcpuid)
{

        return (vm->vcpu[vcpuid].stats);
}

int
vm_get_x2apic_state(struct vm *vm, int vcpuid, enum x2apic_state *state)
{
        if (vcpuid < 0 || vcpuid >= VM_MAXCPU)
                return (EINVAL);

        *state = vm->vcpu[vcpuid].x2apic_state;

        return (0);
}

int
vm_set_x2apic_state(struct vm *vm, int vcpuid, enum x2apic_state state)
{
        if (vcpuid < 0 || vcpuid >= VM_MAXCPU)
                return (EINVAL);

        if (state >= X2APIC_STATE_LAST)
                return (EINVAL);

        vm->vcpu[vcpuid].x2apic_state = state;

        vlapic_set_x2apic_state(vm, vcpuid, state);

        return (0);
}

/*
 * This function is called to ensure that a vcpu "sees" a pending event
 * as soon as possible:
 * - If the vcpu thread is sleeping then it is woken up.
 * - If the vcpu is running on a different host_cpu then an IPI will be directed
 *   to the host_cpu to cause the vcpu to trap into the hypervisor.
 */
void
vcpu_notify_event(struct vm *vm, int vcpuid, bool lapic_intr)
{
        int hostcpu;
        struct vcpu *vcpu;

        vcpu = &vm->vcpu[vcpuid];

        vcpu_lock(vcpu);
        hostcpu = vcpu->hostcpu;
        if (vcpu->state == VCPU_RUNNING) {
                KASSERT(hostcpu != NOCPU, ("vcpu running on invalid hostcpu"));
                if (hostcpu != curcpu) {
                        if (lapic_intr) {
                                vlapic_post_intr(vcpu->vlapic, hostcpu,
                                    vmm_ipinum);
                        } else {
                                ipi_cpu(hostcpu, vmm_ipinum);
                        }
                } else {
                        /*
                         * If the 'vcpu' is running on 'curcpu' then it must
                         * be sending a notification to itself (e.g. SELF_IPI).
                         * The pending event will be picked up when the vcpu
                         * transitions back to guest context.
                         */
                }
        } else {
                KASSERT(hostcpu == NOCPU, ("vcpu state %d not consistent "
                    "with hostcpu %d", vcpu->state, hostcpu));
                if (vcpu->state == VCPU_SLEEPING)
                        wakeup_one(vcpu);
        }
        vcpu_unlock(vcpu);
}

struct vmspace *
vm_get_vmspace(struct vm *vm)
{

        return (vm->vmspace);
}

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

void
vm_smp_rendezvous(struct vm *vm, int vcpuid, cpuset_t dest,
    vm_rendezvous_func_t func, void *arg)
{
        int i;

        /*
         * Enforce that this function is called without any locks
         */
        WITNESS_WARN(WARN_PANIC, NULL, "vm_smp_rendezvous");
        KASSERT(vcpuid == -1 || (vcpuid >= 0 && vcpuid < VM_MAXCPU),
            ("vm_smp_rendezvous: invalid vcpuid %d", vcpuid));

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 'vcpuid' is one
                 * of the targets of the rendezvous.
                 */
                RENDEZVOUS_CTR0(vm, vcpuid, "Rendezvous already in progress");
                mtx_unlock(&vm->rendezvous_mtx);
                vm_handle_rendezvous(vm, vcpuid);
                goto restart;
        }
        KASSERT(vm->rendezvous_func == NULL, ("vm_smp_rendezvous: previous "
            "rendezvous is still in progress"));

        RENDEZVOUS_CTR0(vm, vcpuid, "Initiating rendezvous");
        vm->rendezvous_req_cpus = dest;
        CPU_ZERO(&vm->rendezvous_done_cpus);
        vm->rendezvous_arg = arg;
        vm_set_rendezvous_func(vm, 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_MAXCPU; i++) {
                if (CPU_ISSET(i, &dest))
                        vcpu_notify_event(vm, i, false);
        }

        vm_handle_rendezvous(vm, vcpuid);
}

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

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

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]);
}


/*
 * 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 vm *vm, int vcpu, struct vmm_stat_type *stat)
{

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

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

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

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