/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <sys/xpv_user.h>

#include <sys/types.h>
#include <sys/file.h>
#include <sys/errno.h>
#include <sys/open.h>
#include <sys/cred.h>
#include <sys/conf.h>
#include <sys/stat.h>
#include <sys/modctl.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/vmsystm.h>
#include <sys/hypervisor.h>
#include <sys/xen_errno.h>
#include <sys/sysmacros.h>
#include <sys/sdt.h>

#include <xen/sys/privcmd.h>
#include <sys/privcmd_impl.h>

typedef struct import_export {
        void *                  ie_uaddr;
        void *                  ie_kaddr;
        size_t                  ie_size;
        uint32_t                ie_flags;
} import_export_t;

static import_export_t null_ie = {NULL, NULL, 0, 0};

#define IE_IMPORT       0x0001          /* Data needs to be copied in */
#define IE_EXPORT       0x0002          /* Data needs to be copied out */
#define IE_FREE         0x0004
#define IE_IMPEXP       (IE_IMPORT | IE_EXPORT)

static void *
uaddr_from_handle(void *field)
{
        struct { void *p; } *hdl = field;
        void *ptr;

        /*LINTED: constant in conditional context*/
        get_xen_guest_handle(ptr, (*hdl));
        return (ptr);
}


/*
 * Import a buffer from user-space.  If the caller provides a kernel
 * address, we import to that address.  If not, we kmem_alloc() the space
 * ourselves.
 */
static int
import_buffer(import_export_t *iep, void *uaddr, void *kaddr, size_t size,
    uint32_t flags)
{
        iep->ie_uaddr = uaddr;
        iep->ie_size = size;
        iep->ie_flags = flags & IE_EXPORT;

        if (size == 0 || uaddr == NULL) {
                *iep = null_ie;
                return (0);
        }

        if (kaddr == NULL) {
                iep->ie_kaddr = kmem_alloc(size, KM_SLEEP);
                iep->ie_flags |= IE_FREE;
        } else {
                iep->ie_kaddr = kaddr;
                iep->ie_flags &= ~IE_FREE;
        }

        if ((flags & IE_IMPORT) &&
            (ddi_copyin(uaddr, iep->ie_kaddr, size, 0) != 0)) {
                if (iep->ie_flags & IE_FREE) {
                        kmem_free(iep->ie_kaddr, iep->ie_size);
                        iep->ie_kaddr = NULL;
                        iep->ie_flags = 0;
                }
                return (-X_EFAULT);
        }

        return (0);
}

static void
export_buffer(import_export_t *iep, int *error)
{
        int copy_err = 0;

        if (iep->ie_size == 0 || iep->ie_uaddr == NULL)
                return;

        /*
         * If the buffer was marked for export initially, and if the
         * hypercall completed successfully, resync the user-space buffer
         * with our in-kernel buffer.
         */
        if ((iep->ie_flags & IE_EXPORT) && (*error >= 0) &&
            (ddi_copyout(iep->ie_kaddr, iep->ie_uaddr, iep->ie_size, 0) != 0))
                copy_err = -X_EFAULT;
        if (iep->ie_flags & IE_FREE) {
                kmem_free(iep->ie_kaddr, iep->ie_size);
                iep->ie_kaddr = NULL;
                iep->ie_flags = 0;
        }

        if (copy_err != 0 && *error >= 0)
                *error = copy_err;
}

/*
 * Xen 'op' structures often include pointers disguised as 'handles', which
 * refer to addresses in user space.  This routine copies a buffer
 * associated with an embedded pointer into kernel space, and replaces the
 * pointer to userspace with a pointer to the new kernel buffer.
 *
 * Note: if Xen ever redefines the structure of a 'handle', this routine
 * (specifically the definition of 'hdl') will need to be updated.
 */
static int
import_handle(import_export_t *iep, void *field, size_t size, int flags)
{
        struct { void *p; } *hdl = field;
        void *ptr;
        int err;

        ptr = uaddr_from_handle(field);
        err = import_buffer(iep, ptr, NULL, size, (flags));
        if (err == 0) {
                /*LINTED: constant in conditional context*/
                set_xen_guest_handle((*hdl), (void *)((iep)->ie_kaddr));
        }
        return (err);
}

static int
privcmd_HYPERVISOR_mmu_update(mmu_update_t *ureq, int count, int *scount,
    domid_t domid)
{
        mmu_update_t *kreq, single_kreq;
        import_export_t cnt_ie, req_ie;
        int error, kscount, bytes;

        bytes = count * sizeof (*kreq);
        kreq = (count == 1) ? &single_kreq : kmem_alloc(bytes, KM_SLEEP);

        error = import_buffer(&cnt_ie, scount, &kscount, sizeof (kscount),
            IE_IMPEXP);
        if (error != 0)
                req_ie = null_ie;
        else
                error = import_buffer(&req_ie, ureq, kreq, bytes, IE_IMPEXP);

        DTRACE_XPV3(mmu__update__start, int, domid, int, count, mmu_update_t *,
            ((error == -X_EFAULT) ? ureq : kreq));

        if (error == 0)
                error = HYPERVISOR_mmu_update(kreq, count, &kscount, domid);
        export_buffer(&cnt_ie, &error);
        export_buffer(&req_ie, &error);
        if (count != 1)
                kmem_free(kreq, bytes);

        DTRACE_XPV1(mmu__update__end, int, error);
        return (error);
}

static int
privcmd_HYPERVISOR_domctl(xen_domctl_t *opp)
{
        xen_domctl_t op;
        import_export_t op_ie, sub_ie;
        int error = 0;

        if ((error = import_buffer(&op_ie, opp, &op, sizeof (op),
            IE_IMPEXP)) != 0)
                return (error);

        sub_ie = null_ie;

        /*
         * Check this first because our wrapper will forcibly overwrite it.
         */
        if (op.interface_version != XEN_DOMCTL_INTERFACE_VERSION) {
#ifdef DEBUG
                printf("domctl vers mismatch (cmd %d, found 0x%x, need 0x%x\n",
                    op.cmd, op.interface_version, XEN_DOMCTL_INTERFACE_VERSION);
#endif
                error = -X_EACCES;
                export_buffer(&op_ie, &error);
                return (error);
        }

        /*
         * Now handle any domctl ops with embedded pointers elsewhere
         * in the user address space that also need to be tacked down
         * while the hypervisor futzes with them.
         */
        switch (op.cmd) {
        case XEN_DOMCTL_createdomain:
                DTRACE_XPV1(dom__create__start, xen_domctl_t *,
                    &op.u.createdomain);
                break;

        case XEN_DOMCTL_destroydomain:
                DTRACE_XPV1(dom__destroy__start, domid_t, op.domain);
                break;

        case XEN_DOMCTL_pausedomain:
                DTRACE_XPV1(dom__pause__start, domid_t, op.domain);
                break;

        case XEN_DOMCTL_unpausedomain:
                DTRACE_XPV1(dom__unpause__start, domid_t, op.domain);
                break;

        case XEN_DOMCTL_getmemlist: {
                error = import_handle(&sub_ie, &op.u.getmemlist.buffer,
                    op.u.getmemlist.max_pfns * sizeof (xen_pfn_t), IE_EXPORT);
                break;
        }

        case XEN_DOMCTL_getpageframeinfo2: {
                error = import_handle(&sub_ie, &op.u.getpageframeinfo2.array,
                    op.u.getpageframeinfo2.num * sizeof (ulong_t), IE_IMPEXP);
                break;
        }

        case XEN_DOMCTL_shadow_op: {
                size_t size;

                size = roundup(howmany(op.u.shadow_op.pages, NBBY),
                    sizeof (ulong_t));
                error = import_handle(&sub_ie,
                    &op.u.shadow_op.dirty_bitmap, size, IE_IMPEXP);
                break;
        }

        case XEN_DOMCTL_setvcpucontext: {
                vcpu_guest_context_t *taddr;
                error = import_handle(&sub_ie, &op.u.vcpucontext.ctxt,
                    sizeof (vcpu_guest_context_t), IE_IMPORT);
                if (error == -X_EFAULT)
                        /*LINTED: constant in conditional context*/
                        get_xen_guest_handle_u(taddr, op.u.vcpucontext.ctxt);
                else
                        taddr = sub_ie.ie_kaddr;
                DTRACE_XPV2(setvcpucontext__start, domid_t, op.domain,
                    vcpu_guest_context_t *, taddr);
                break;
        }

        case XEN_DOMCTL_getvcpucontext: {
                error = import_handle(&sub_ie, &op.u.vcpucontext.ctxt,
                    sizeof (vcpu_guest_context_t), IE_EXPORT);
                break;
        }


        case XEN_DOMCTL_sethvmcontext: {
                error = import_handle(&sub_ie, &op.u.hvmcontext.buffer,
                    op.u.hvmcontext.size, IE_IMPORT);
                break;
        }

        case XEN_DOMCTL_gethvmcontext: {
                if (op.u.hvmcontext.buffer.p != NULL)
                        error = import_handle(&sub_ie, &op.u.hvmcontext.buffer,
                            op.u.hvmcontext.size, IE_EXPORT);
                break;
        }

        case XEN_DOMCTL_getdomaininfo:
        case XEN_DOMCTL_getpageframeinfo:
        case XEN_DOMCTL_max_mem:
        case XEN_DOMCTL_resumedomain:
        case XEN_DOMCTL_getvcpuinfo:
        case XEN_DOMCTL_setvcpuaffinity:
        case XEN_DOMCTL_getvcpuaffinity:
        case XEN_DOMCTL_max_vcpus:
        case XEN_DOMCTL_scheduler_op:
        case XEN_DOMCTL_setdomainhandle:
        case XEN_DOMCTL_setdebugging:
        case XEN_DOMCTL_irq_permission:
        case XEN_DOMCTL_iomem_permission:
        case XEN_DOMCTL_ioport_permission:
        case XEN_DOMCTL_hypercall_init:
        case XEN_DOMCTL_arch_setup:
        case XEN_DOMCTL_settimeoffset:
        case XEN_DOMCTL_real_mode_area:
        case XEN_DOMCTL_sendtrigger:
        case XEN_DOMCTL_assign_device:
        case XEN_DOMCTL_bind_pt_irq:
        case XEN_DOMCTL_get_address_size:
        case XEN_DOMCTL_set_address_size:
        case XEN_DOMCTL_get_ext_vcpucontext:
        case XEN_DOMCTL_set_ext_vcpucontext:
        case XEN_DOMCTL_set_opt_feature:
        case XEN_DOMCTL_memory_mapping:
        case XEN_DOMCTL_ioport_mapping:
        case XEN_DOMCTL_pin_mem_cacheattr:
        case XEN_DOMCTL_test_assign_device:
        case XEN_DOMCTL_set_target:
        case XEN_DOMCTL_deassign_device:
        case XEN_DOMCTL_set_cpuid:
        case XEN_DOMCTL_get_device_group:
        case XEN_DOMCTL_get_machine_address_size:
        case XEN_DOMCTL_set_machine_address_size:
        case XEN_DOMCTL_suppress_spurious_page_faults:
                break;

        default:
#ifdef DEBUG
                printf("unrecognized HYPERVISOR_domctl %d\n", op.cmd);
#endif
                error = -X_EINVAL;
        }

        if (error == 0)
                error = HYPERVISOR_domctl(&op);

        export_buffer(&op_ie, &error);
        export_buffer(&sub_ie, &error);

        switch (op.cmd) {
        case XEN_DOMCTL_createdomain:
                DTRACE_XPV1(dom__create__end, int, error);
                break;
        case XEN_DOMCTL_destroydomain:
                DTRACE_XPV1(dom__destroy__end, int, error);
                break;
        case XEN_DOMCTL_pausedomain:
                DTRACE_XPV1(dom__pause__end, int, error);
                break;
        case XEN_DOMCTL_unpausedomain:
                DTRACE_XPV1(dom__unpause__end, int, error);
                break;
        case XEN_DOMCTL_setvcpucontext:
                DTRACE_XPV1(setvcpucontext__end, int, error);
                break;
        default:
                ;
        }

        return (error);
}

static int
privcmd_HYPERVISOR_sysctl(xen_sysctl_t *opp)
{
        xen_sysctl_t op, dop;
        import_export_t op_ie, sub_ie, sub2_ie;
        int error = 0;

        if (import_buffer(&op_ie, opp, &op, sizeof (op), IE_IMPEXP) != 0)
                return (-X_EFAULT);

        sub_ie = null_ie;
        sub2_ie = null_ie;

        /*
         * Check this first because our wrapper will forcibly overwrite it.
         */
        if (op.interface_version != XEN_SYSCTL_INTERFACE_VERSION) {
                error = -X_EACCES;
                export_buffer(&op_ie, &error);
                return (error);
        }

        switch (op.cmd) {
        case XEN_SYSCTL_readconsole: {
                error = import_handle(&sub_ie, &op.u.readconsole.buffer,
                    op.u.readconsole.count, IE_EXPORT);
                break;
        }

        case XEN_SYSCTL_debug_keys: {
                error = import_handle(&sub_ie, &op.u.debug_keys.keys,
                    op.u.debug_keys.nr_keys, IE_IMPORT);
                break;
        }

        case XEN_SYSCTL_tbuf_op:
        case XEN_SYSCTL_physinfo: {
                if (uaddr_from_handle(&op.u.physinfo.cpu_to_node) != NULL &&
                    op.u.physinfo.max_cpu_id != 0) {
                        error = import_handle(&sub_ie,
                            &op.u.physinfo.cpu_to_node,
                            op.u.physinfo.max_cpu_id * sizeof (uint32_t),
                            IE_EXPORT);
                }
                break;
        }
        case XEN_SYSCTL_sched_id:
        case XEN_SYSCTL_availheap:
        case XEN_SYSCTL_cpu_hotplug:
                break;
        case XEN_SYSCTL_get_pmstat: {
                unsigned int maxs;

                switch (op.u.get_pmstat.type) {
                case PMSTAT_get_pxstat:
                        /*
                         * This interface is broken. Xen always copies out
                         * all the state information, and the interface
                         * does not specify how much space the caller has
                         * reserved. So, the only thing to do is just mirror
                         * the hypervisor and libxc behavior, and use the
                         * maximum amount of data.
                         */
                        dop.cmd = XEN_SYSCTL_get_pmstat;
                        dop.interface_version = XEN_SYSCTL_INTERFACE_VERSION;
                        dop.u.get_pmstat.cpuid = op.u.get_pmstat.cpuid;
                        dop.u.get_pmstat.type = PMSTAT_get_max_px;
                        error = HYPERVISOR_sysctl(&dop);
                        if (error != 0)
                                break;

                        maxs = dop.u.get_pmstat.u.getpx.total;
                        if (maxs == 0) {
                                error = -X_EINVAL;
                                break;
                        }

                        error = import_handle(&sub_ie,
                            &op.u.get_pmstat.u.getpx.trans_pt,
                            maxs * maxs * sizeof (uint64_t), IE_EXPORT);
                        if (error != 0)
                                break;

                        error = import_handle(&sub2_ie,
                            &op.u.get_pmstat.u.getpx.pt,
                            maxs * sizeof (pm_px_val_t), IE_EXPORT);
                        break;
                case PMSTAT_get_cxstat:
                        /* See above */
                        dop.cmd = XEN_SYSCTL_get_pmstat;
                        dop.interface_version = XEN_SYSCTL_INTERFACE_VERSION;
                        dop.u.get_pmstat.cpuid = op.u.get_pmstat.cpuid;
                        dop.u.get_pmstat.type = PMSTAT_get_max_cx;
                        error = HYPERVISOR_sysctl(&dop);
                        if (error != 0)
                                break;

                        maxs = dop.u.get_pmstat.u.getcx.nr;
                        if (maxs == 0) {
                                error = -X_EINVAL;
                                break;
                        }

                        error = import_handle(&sub_ie,
                            &op.u.get_pmstat.u.getcx.triggers,
                            maxs * sizeof (uint64_t), IE_EXPORT);
                        if (error != 0)
                                break;
                        error = import_handle(&sub2_ie,
                            &op.u.get_pmstat.u.getcx.residencies,
                            maxs * sizeof (uint64_t), IE_EXPORT);
                        break;

                case PMSTAT_get_max_px:
                case PMSTAT_reset_pxstat:
                case PMSTAT_get_max_cx:
                case PMSTAT_reset_cxstat:
                        break;
                default:
                        error = -X_EINVAL;
                        break;
                }
                break;
        }

        case XEN_SYSCTL_perfc_op: {
                xen_sysctl_perfc_desc_t *scdp;
                /*
                 * If 'desc' is NULL, then the caller is asking for
                 * the number of counters.  If 'desc' is non-NULL,
                 * then we need to know how many counters there are
                 * before wiring down the output buffer appropriately.
                 */
                /*LINTED: constant in conditional context*/
                get_xen_guest_handle_u(scdp, op.u.perfc_op.desc);
                if (scdp != NULL) {
                        static int numcounters = -1;
                        static int numvals = -1;

                        if (numcounters == -1) {
                                dop.cmd = XEN_SYSCTL_perfc_op;
                                dop.interface_version =
                                    XEN_SYSCTL_INTERFACE_VERSION;
                                dop.u.perfc_op.cmd = XEN_SYSCTL_PERFCOP_query;
                                /*LINTED: constant in conditional context*/
                                set_xen_guest_handle_u(dop.u.perfc_op.desc,
                                    NULL);
                                /*LINTED: constant in conditional context*/
                                set_xen_guest_handle_u(dop.u.perfc_op.val,
                                    NULL);

                                error = HYPERVISOR_sysctl(&dop);
                                if (error != 0)
                                        break;
                                numcounters = dop.u.perfc_op.nr_counters;
                                numvals = dop.u.perfc_op.nr_vals;
                        }
                        ASSERT(numcounters != -1);
                        ASSERT(numvals != -1);
                        error = import_handle(&sub_ie, &op.u.perfc_op.desc,
                            (sizeof (xen_sysctl_perfc_desc_t) * numcounters),
                            IE_EXPORT);
                        error = import_handle(&sub2_ie, &op.u.perfc_op.val,
                            (sizeof (xen_sysctl_perfc_val_t) * numvals),
                            IE_EXPORT);
                }
                break;
        }

        case XEN_SYSCTL_getdomaininfolist: {
                error = import_handle(&sub_ie, &op.u.getdomaininfolist.buffer,
                    (op.u.getdomaininfolist.max_domains *
                    sizeof (xen_domctl_getdomaininfo_t)), IE_EXPORT);
                break;
        }

        case XEN_SYSCTL_getcpuinfo:
                error = import_handle(&sub_ie, &op.u.getcpuinfo.info,
                    op.u.getcpuinfo.max_cpus *
                    sizeof (xen_sysctl_cpuinfo_t), IE_EXPORT);
                break;
        default:
#ifdef DEBUG
                printf("unrecognized HYPERVISOR_sysctl %d\n", op.cmd);
#endif
                error = -X_EINVAL;
        }

        if (error == 0)
                error = HYPERVISOR_sysctl(&op);

        export_buffer(&op_ie, &error);
        export_buffer(&sub_ie, &error);
        export_buffer(&sub2_ie, &error);

        return (error);
}

static int
privcmd_HYPERVISOR_platform_op(xen_platform_op_t *opp)
{
        import_export_t op_ie, sub_ie, sub2_ie;
        xen_platform_op_t op;
        int error;

        if (import_buffer(&op_ie, opp, &op, sizeof (op), IE_IMPEXP) != 0)
                return (-X_EFAULT);

        sub_ie = null_ie;
        sub2_ie = null_ie;

        /*
         * Check this first because our wrapper will forcibly overwrite it.
         */
        if (op.interface_version != XENPF_INTERFACE_VERSION) {
                error = -X_EACCES;
                export_buffer(&op_ie, &error);
                return (error);
        }

        /*
         * Now handle any platform ops with embedded pointers elsewhere
         * in the user address space that also need to be tacked down
         * while the hypervisor futzes with them.
         */
        switch (op.cmd) {
        case XENPF_settime:
        case XENPF_add_memtype:
        case XENPF_del_memtype:
        case XENPF_read_memtype:
        case XENPF_platform_quirk:
        case XENPF_enter_acpi_sleep:
        case XENPF_change_freq:
        case XENPF_panic_init:
                break;

        case XENPF_microcode_update:
                error = import_handle(&sub_ie, &op.u.microcode.data,
                    op.u.microcode.length, IE_IMPORT);
                break;
        case XENPF_getidletime:
                error = import_handle(&sub_ie, &op.u.getidletime.cpumap_bitmap,
                    op.u.getidletime.cpumap_nr_cpus, IE_IMPEXP);
                if (error != 0)
                        break;

                error = import_handle(&sub2_ie, &op.u.getidletime.idletime,
                    op.u.getidletime.cpumap_nr_cpus * sizeof (uint64_t),
                    IE_EXPORT);
                break;

        case XENPF_set_processor_pminfo: {
                size_t s;

                switch (op.u.set_pminfo.type) {
                case XEN_PM_PX:
                        s = op.u.set_pminfo.u.perf.state_count *
                            sizeof (xen_processor_px_t);
                        if (op.u.set_pminfo.u.perf.flags & XEN_PX_PSS) {
                                error = import_handle(&sub_ie,
                                    &op.u.set_pminfo.u.perf.states, s,
                                    IE_IMPORT);
                        }
                        break;
                case XEN_PM_CX:
                        s = op.u.set_pminfo.u.power.count *
                            sizeof (xen_processor_cx_t);
                        error = import_handle(&sub_ie,
                            &op.u.set_pminfo.u.power.states, s, IE_IMPORT);
                        break;
                case XEN_PM_TX:
                        break;
                default:
                        error = -X_EINVAL;
                        break;
                }
                break;
        }
        case XENPF_firmware_info: {
                uint16_t len;
                void *uaddr;

                switch (op.u.firmware_info.type) {
                case XEN_FW_DISK_INFO:
                        /*
                         * Ugh.. another hokey interface. The first 16 bits
                         * of the buffer are also used as the (input) length.
                         */
                        uaddr = uaddr_from_handle(
                            &op.u.firmware_info.u.disk_info.edd_params);
                        error = ddi_copyin(uaddr, &len, sizeof (len), 0);
                        if (error != 0)
                                break;
                        error = import_handle(&sub_ie,
                            &op.u.firmware_info.u.disk_info.edd_params, len,
                            IE_IMPEXP);
                        break;
                case XEN_FW_VBEDDC_INFO:
                        error = import_handle(&sub_ie,
                            &op.u.firmware_info.u.vbeddc_info.edid, 128,
                            IE_EXPORT);
                        break;
                case XEN_FW_DISK_MBR_SIGNATURE:
                default:
                        break;
                }
                break;
        }
        default:
                /* FIXME: see this with non-existed ID 38 ???? */
#ifdef DEBUG
                printf("unrecognized HYPERVISOR_platform_op %d pid %d\n",
                    op.cmd, curthread->t_procp->p_pid);
#endif
                return (-X_EINVAL);
        }

        if (error == 0)
                error = HYPERVISOR_platform_op(&op);

        export_buffer(&op_ie, &error);
        export_buffer(&sub_ie, &error);
        export_buffer(&sub2_ie, &error);

        return (error);
}

static int
privcmd_HYPERVISOR_memory_op(int cmd, void *arg)
{
        int error = 0;
        import_export_t op_ie, sub_ie, gpfn_ie, mfn_ie;
        union {
                domid_t domid;
                struct xen_memory_reservation resv;
                struct xen_machphys_mfn_list xmml;
                struct xen_add_to_physmap xatp;
                struct xen_memory_map mm;
                struct xen_foreign_memory_map fmm;
                struct xen_pod_target pd;
        } op_arg;

        op_ie = sub_ie = gpfn_ie = mfn_ie = null_ie;

        switch (cmd) {
        case XENMEM_increase_reservation:
        case XENMEM_decrease_reservation:
        case XENMEM_populate_physmap: {
                ulong_t *taddr;

                if (import_buffer(&op_ie, arg, &op_arg, sizeof (op_arg.resv),
                    IE_IMPEXP) != 0)
                        return (-X_EFAULT);

                error = import_handle(&sub_ie, &op_arg.resv.extent_start,
                    (op_arg.resv.nr_extents * sizeof (ulong_t)), IE_IMPEXP);

                if (error == -X_EFAULT)
                        /*LINTED: constant in conditional context*/
                        get_xen_guest_handle(taddr, op_arg.resv.extent_start);
                else
                        taddr = sub_ie.ie_kaddr;

                switch (cmd) {
                case XENMEM_increase_reservation:
                        DTRACE_XPV4(increase__reservation__start,
                            domid_t, op_arg.resv.domid,
                            ulong_t, op_arg.resv.nr_extents,
                            uint_t, op_arg.resv.extent_order,
                            ulong_t *, taddr);
                        break;
                case XENMEM_decrease_reservation:
                        DTRACE_XPV4(decrease__reservation__start,
                            domid_t, op_arg.resv.domid,
                            ulong_t, op_arg.resv.nr_extents,
                            uint_t, op_arg.resv.extent_order,
                            ulong_t *, taddr);
                        break;
                case XENMEM_populate_physmap:
                        DTRACE_XPV3(populate__physmap__start,
                            domid_t, op_arg.resv.domid,
                            ulong_t, op_arg.resv.nr_extents,
                            ulong_t *, taddr);
                        break;
                }

                break;
        }

        case XENMEM_maximum_ram_page:
                break;

        case XENMEM_current_reservation:
        case XENMEM_maximum_reservation:
        case XENMEM_maximum_gpfn:
                if (import_buffer(&op_ie, arg, &op_arg, sizeof (op_arg.domid),
                    IE_IMPEXP) != 0)
                        return (-X_EFAULT);
                break;

        case XENMEM_machphys_mfn_list: {
                if (import_buffer(&op_ie, arg, &op_arg, sizeof (op_arg.xmml),
                    IE_IMPEXP) != 0)
                        return (-X_EFAULT);

                error = import_handle(&sub_ie, &op_arg.xmml.extent_start,
                    (op_arg.xmml.max_extents * sizeof (ulong_t)), IE_IMPEXP);
                break;
        }

        case XENMEM_add_to_physmap:
                if (import_buffer(&op_ie, arg, &op_arg, sizeof (op_arg.xatp),
                    IE_IMPEXP) != 0)
                        return (-X_EFAULT);
                DTRACE_XPV4(add__to__physmap__start, domid_t,
                    op_arg.xatp.domid, uint_t, op_arg.xatp.space, ulong_t,
                    op_arg.xatp.idx, ulong_t, op_arg.xatp.gpfn);
                break;

        case XENMEM_memory_map:
        case XENMEM_machine_memory_map: {
                if (import_buffer(&op_ie, arg, &op_arg, sizeof (op_arg.mm),
                    IE_EXPORT) != 0)
                        return (-X_EFAULT);

                /*
                 * XXPV: ugh. e820entry is packed, but not in the kernel, since
                 * we remove all attributes; seems like this is a nice way to
                 * break mysteriously.
                 */
                error = import_handle(&sub_ie, &op_arg.mm.buffer,
                    (op_arg.mm.nr_entries * 20), IE_IMPEXP);
                break;
        }

        case XENMEM_set_memory_map: {
                struct xen_memory_map *taddr;
                if (import_buffer(&op_ie, arg, &op_arg, sizeof (op_arg.fmm),
                    IE_IMPORT) != 0)
                        return (-X_EFAULT);

                /*
                 * As above.
                 */
                error = import_handle(&sub_ie, &op_arg.fmm.map.buffer,
                    (op_arg.fmm.map.nr_entries * 20), IE_IMPEXP);

                if (error == -X_EFAULT)
                        /*LINTED: constant in conditional context*/
                        get_xen_guest_handle(taddr, op_arg.fmm.map.buffer);
                else
                        taddr = sub_ie.ie_kaddr;
                DTRACE_XPV3(set__memory__map__start, domid_t,
                    op_arg.fmm.domid, int, op_arg.fmm.map.nr_entries,
                    struct xen_memory_map *, taddr);
                break;
        }

        case XENMEM_set_pod_target:
        case XENMEM_get_pod_target:
                if (import_buffer(&op_ie, arg, &op_arg, sizeof (op_arg.pd),
                    IE_IMPEXP) != 0)
                        return (-X_EFAULT);
                break;

        default:
#ifdef DEBUG
                printf("unrecognized HYPERVISOR_memory_op %d\n", cmd);
#endif
                return (-X_EINVAL);
        }

        if (error == 0)
                error = HYPERVISOR_memory_op(cmd,
                    (arg == NULL) ? NULL: &op_arg);

        export_buffer(&op_ie, &error);
        export_buffer(&sub_ie, &error);
        export_buffer(&gpfn_ie, &error);
        export_buffer(&mfn_ie, &error);

        switch (cmd) {
        case XENMEM_increase_reservation:
                DTRACE_XPV1(increase__reservation__end, int, error);
                break;
        case XENMEM_decrease_reservation:
                DTRACE_XPV1(decrease__reservation__end, int, error);
                break;
        case XENMEM_populate_physmap:
                DTRACE_XPV1(populate__physmap__end, int, error);
                break;
        case XENMEM_add_to_physmap:
                DTRACE_XPV1(add__to__physmap__end, int, error);
                break;
        case XENMEM_set_memory_map:
                DTRACE_XPV1(set__memory__map__end, int, error);
                break;
        }
        return (error);
}

static int
privcmd_HYPERVISOR_event_channel_op(int cmd, void *arg)
{
        int error;
        size_t size;
        import_export_t op_ie;
        uint32_t flags;

        switch (cmd) {
        case EVTCHNOP_alloc_unbound:
                size = sizeof (evtchn_alloc_unbound_t);
                flags = IE_IMPEXP;
                break;
        case EVTCHNOP_bind_interdomain:
                size = sizeof (evtchn_bind_interdomain_t);
                flags = IE_IMPEXP;
                break;
        case EVTCHNOP_bind_virq:
                size = sizeof (evtchn_bind_virq_t);
                flags = IE_IMPEXP;
                break;
        case EVTCHNOP_bind_pirq:
                size = sizeof (evtchn_bind_pirq_t);
                flags = IE_IMPEXP;
                break;
        case EVTCHNOP_bind_ipi:
                size = sizeof (evtchn_bind_ipi_t);
                flags = IE_IMPEXP;
                break;
        case EVTCHNOP_close:
                size = sizeof (evtchn_close_t);
                flags = IE_IMPORT;
                break;
        case EVTCHNOP_send:
                size = sizeof (evtchn_send_t);
                flags = IE_IMPORT;
                break;
        case EVTCHNOP_status:
                size = sizeof (evtchn_status_t);
                flags = IE_IMPEXP;
                break;
        case EVTCHNOP_bind_vcpu:
                size = sizeof (evtchn_bind_vcpu_t);
                flags = IE_IMPORT;
                break;
        case EVTCHNOP_unmask:
                size = sizeof (evtchn_unmask_t);
                flags = IE_IMPORT;
                break;
        case EVTCHNOP_reset:
                size = sizeof (evtchn_reset_t);
                flags = IE_IMPORT;
                break;

        default:
#ifdef DEBUG
                printf("unrecognized HYPERVISOR_event_channel op %d\n", cmd);
#endif
                return (-X_EINVAL);
        }

        error = import_buffer(&op_ie, arg, NULL, size, flags);

        /*
         * If there is sufficient demand, we can replace this void * with
         * the proper op structure pointer.
         */
        DTRACE_XPV2(evtchn__op__start, int, cmd, void *,
            ((error == -X_EFAULT) ? arg : op_ie.ie_kaddr));

        if (error == 0)
                error = HYPERVISOR_event_channel_op(cmd, op_ie.ie_kaddr);
        export_buffer(&op_ie, &error);

        DTRACE_XPV1(evtchn__op__end, int, error);

        return (error);
}

static int
privcmd_HYPERVISOR_xen_version(int cmd, void *arg)
{
        int error;
        int size = 0;
        import_export_t op_ie;
        uint32_t flags = IE_EXPORT;

        switch (cmd) {
        case XENVER_version:
                break;
        case XENVER_extraversion:
                size = sizeof (xen_extraversion_t);
                break;
        case XENVER_compile_info:
                size = sizeof (xen_compile_info_t);
                break;
        case XENVER_capabilities:
                size = sizeof (xen_capabilities_info_t);
                break;
        case XENVER_changeset:
                size = sizeof (xen_changeset_info_t);
                break;
        case XENVER_platform_parameters:
                size = sizeof (xen_platform_parameters_t);
                break;
        case XENVER_get_features:
                flags = IE_IMPEXP;
                size = sizeof (xen_feature_info_t);
                break;
        case XENVER_pagesize:
                break;
        case XENVER_guest_handle:
                size = sizeof (xen_domain_handle_t);
                break;

        default:
#ifdef DEBUG
                printf("unrecognized HYPERVISOR_xen_version op %d\n", cmd);
#endif
                return (-X_EINVAL);
        }

        error = import_buffer(&op_ie, arg, NULL, size, flags);
        if (error == 0)
                error = HYPERVISOR_xen_version(cmd, op_ie.ie_kaddr);
        export_buffer(&op_ie, &error);

        return (error);
}

static int
privcmd_HYPERVISOR_xsm_op(void *uacmctl)
{
        int error;
        struct xen_acmctl *acmctl;
        import_export_t op_ie;

        error = import_buffer(&op_ie, uacmctl, NULL, sizeof (*acmctl),
            IE_IMPEXP);
        if (error != 0)
                return (error);

        acmctl = op_ie.ie_kaddr;

        if (acmctl->interface_version != ACM_INTERFACE_VERSION) {
#ifdef DEBUG
                printf("acm vers mismatch (cmd %d, found 0x%x, need 0x%x\n",
                    acmctl->cmd, acmctl->interface_version,
                    ACM_INTERFACE_VERSION);
#endif
                error = -X_EACCES;
                export_buffer(&op_ie, &error);
                return (error);
        }

        /* FIXME: flask ops??? */

        switch (acmctl->cmd) {
        case ACMOP_setpolicy:
        case ACMOP_getpolicy:
        case ACMOP_dumpstats:
        case ACMOP_getssid:
        case ACMOP_getdecision:
        case ACMOP_chgpolicy:
        case ACMOP_relabeldoms:
                /* flags = IE_IMPEXP; */
                break;
        default:
#ifdef DEBUG
                printf("unrecognized HYPERVISOR_xsm_op op %d\n", acmctl->cmd);
#endif
                return (-X_EINVAL);
        }

        if (error == 0)
                error = HYPERVISOR_xsm_op(acmctl);
        export_buffer(&op_ie, &error);

        return (error);
}

static int
privcmd_HYPERVISOR_mmuext_op(struct mmuext_op *op, int count, uint_t *scount,
    domid_t domid)
{
        int error, bytes;
        uint_t kscount;
        struct mmuext_op *kop, single_kop;
        import_export_t op_ie, scnt_ie;

        kop = NULL;
        op_ie = scnt_ie = null_ie;
        error = 0;

        if (count >= 1) {
                bytes = count * sizeof (*kop);
                kop = (count == 1) ? &single_kop : kmem_alloc(bytes, KM_SLEEP);
                error = import_buffer(&op_ie, op, kop, bytes, IE_IMPORT);
        }

        DTRACE_XPV2(mmu__ext__op__start, int, count, struct mmuext_op *,
            ((error == -X_EFAULT) ? op : kop));

        if (scount != NULL && error == 0)
                error = import_buffer(&scnt_ie, scount, &kscount,
                    sizeof (kscount), IE_EXPORT);

        if (error == 0)
                error = HYPERVISOR_mmuext_op(kop, count, &kscount, domid);
        export_buffer(&op_ie, &error);
        export_buffer(&scnt_ie, &error);

        DTRACE_XPV1(mmu__ext__op__end, int, error);

        if (count > 1)
                kmem_free(kop, bytes);
        return (error);
}

static int
privcmd_HYPERVISOR_hvm_op(int cmd, void *arg)
{
        int error;
        int size = 0;
        import_export_t arg_ie;
        uint32_t flags = IE_IMPORT;

        switch (cmd) {
        case HVMOP_set_param:
        case HVMOP_get_param:
                size = sizeof (struct xen_hvm_param);
                flags = IE_IMPEXP;
                break;
        case HVMOP_set_pci_intx_level:
                size = sizeof (struct xen_hvm_set_pci_intx_level);
                break;
        case HVMOP_set_isa_irq_level:
                size = sizeof (struct xen_hvm_set_isa_irq_level);
                break;
        case HVMOP_set_pci_link_route:
                size = sizeof (struct xen_hvm_set_pci_link_route);
                break;
        case HVMOP_track_dirty_vram:
                size = sizeof (struct xen_hvm_track_dirty_vram);
                break;
        case HVMOP_modified_memory:
                size = sizeof (struct xen_hvm_modified_memory);
                break;
        case HVMOP_set_mem_type:
                size = sizeof (struct xen_hvm_set_mem_type);
                break;

        default:
#ifdef DEBUG
                printf("unrecognized HVM op 0x%x\n", cmd);
#endif
                return (-X_EINVAL);
        }

        error = import_buffer(&arg_ie, arg, NULL, size, flags);
        if (error == 0)
                error = HYPERVISOR_hvm_op(cmd, arg_ie.ie_kaddr);
        export_buffer(&arg_ie, &error);

        return (error);
}

static int
privcmd_HYPERVISOR_sched_op(int cmd, void *arg)
{
        int error;
        int size = 0;
        import_export_t op_ie;
        struct sched_remote_shutdown op;

        switch (cmd) {
        case SCHEDOP_remote_shutdown:
                size = sizeof (struct sched_remote_shutdown);
                break;
        default:
#ifdef DEBUG
                printf("unrecognized sched op 0x%x\n", cmd);
#endif
                return (-X_EINVAL);
        }

        error = import_buffer(&op_ie, arg, &op, size, IE_IMPORT);
        if (error == 0)
                error = HYPERVISOR_sched_op(cmd, (arg == NULL) ? NULL : &op);
        export_buffer(&op_ie, &error);

        return (error);
}

int allow_all_hypercalls = 0;
int privcmd_efault_debug = 0;

/*ARGSUSED*/
int
do_privcmd_hypercall(void *uarg, int mode, cred_t *cr, int *rval)
{
        privcmd_hypercall_t __hc, *hc = &__hc;
        int error;

        if (ddi_copyin(uarg, hc, sizeof (*hc), mode))
                return (EFAULT);

        switch (hc->op) {
        case __HYPERVISOR_mmu_update:
                error = privcmd_HYPERVISOR_mmu_update(
                    (mmu_update_t *)hc->arg[0], (int)hc->arg[1],
                    (int *)hc->arg[2], (domid_t)hc->arg[3]);
                break;
        case __HYPERVISOR_domctl:
                error = privcmd_HYPERVISOR_domctl(
                    (xen_domctl_t *)hc->arg[0]);
                break;
        case __HYPERVISOR_sysctl:
                error = privcmd_HYPERVISOR_sysctl(
                    (xen_sysctl_t *)hc->arg[0]);
                break;
        case __HYPERVISOR_platform_op:
                error = privcmd_HYPERVISOR_platform_op(
                    (xen_platform_op_t *)hc->arg[0]);
                break;
        case __HYPERVISOR_memory_op:
                error = privcmd_HYPERVISOR_memory_op(
                    (int)hc->arg[0], (void *)hc->arg[1]);
                break;
        case __HYPERVISOR_event_channel_op:
                error = privcmd_HYPERVISOR_event_channel_op(
                    (int)hc->arg[0], (void *)hc->arg[1]);
                break;
        case __HYPERVISOR_xen_version:
                error = privcmd_HYPERVISOR_xen_version(
                    (int)hc->arg[0], (void *)hc->arg[1]);
                break;
        case __HYPERVISOR_mmuext_op:
                error = privcmd_HYPERVISOR_mmuext_op(
                    (struct mmuext_op *)hc->arg[0], (int)hc->arg[1],
                    (uint_t *)hc->arg[2], (domid_t)hc->arg[3]);
                break;
        case __HYPERVISOR_xsm_op:
                error = privcmd_HYPERVISOR_xsm_op((void *)hc->arg[0]);
                break;
        case __HYPERVISOR_hvm_op:
                error = privcmd_HYPERVISOR_hvm_op(
                    (int)hc->arg[0], (void *)hc->arg[1]);
                break;
        case __HYPERVISOR_sched_op:
                error = privcmd_HYPERVISOR_sched_op(
                    (int)hc->arg[0], (void *)hc->arg[1]);
                break;
        default:
                if (allow_all_hypercalls)
                        error = __hypercall5(hc->op, hc->arg[0], hc->arg[1],
                            hc->arg[2], hc->arg[3], hc->arg[4]);
                else {
#ifdef DEBUG
                        printf("unrecognized hypercall %ld\n", hc->op);
#endif
                        error = -X_EPERM;
                }
                break;
        }

        if (error > 0) {
                *rval = error;
                error = 0;
        } else if (error != 0)
                error = xen_xlate_errcode(error);

        return (error);
}