sun4v/io/dr_mem.c

/*
 * 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 (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
 */

/*
 * sun4v Memory DR Module
 */


#include <sys/types.h>
#include <sys/cmn_err.h>
#include <sys/vmem.h>
#include <sys/kmem.h>
#include <sys/systm.h>
#include <sys/machsystm.h>  /* for page_freelist_coalesce() */
#include <sys/errno.h>
#include <sys/memnode.h>
#include <sys/memlist.h>
#include <sys/memlist_impl.h>
#include <sys/tuneable.h>
#include <sys/proc.h>
#include <sys/disp.h>
#include <sys/debug.h>
#include <sys/vm.h>
#include <sys/callb.h>
#include <sys/memlist_plat.h>   /* for installed_top_size() */
#include <sys/condvar_impl.h>   /* for CV_HAS_WAITERS() */
#include <sys/dumphdr.h>    /* for dump_resize() */
#include <sys/atomic.h>     /* for use in stats collection */
#include <sys/rwlock.h>
#include <vm/seg_kmem.h>
#include <vm/seg_kpm.h>
#include <vm/page.h>
#include <vm/vm_dep.h>
#define SUNDDI_IMPL     /* so sunddi.h will not redefine splx() et al */
#include <sys/sunddi.h>
#include <sys/mem_config.h>
#include <sys/mem_cage.h>
#include <sys/lgrp.h>
#include <sys/ddi.h>

#include <sys/modctl.h>
#include <sys/sysevent/dr.h>
#include <sys/mach_descrip.h>
#include <sys/mdesc.h>
#include <sys/ds.h>
#include <sys/drctl.h>
#include <sys/dr_util.h>
#include <sys/dr_mem.h>
#include <sys/suspend.h>


/*
 * DR operations are subject to Memory Alignment restrictions
 * for both address and the size of the request.
 */
#define MA_ADDR 0x10000000  /* addr alignment 256M */
#define MA_SIZE 0x10000000  /* size alignment 256M */

#define MBLK_IS_VALID(m) \
    (IS_P2ALIGNED((m)->addr, MA_ADDR) && IS_P2ALIGNED((m)->size, MA_SIZE))

static memhandle_t dr_mh;   /* memory handle for delete */

static struct modlmisc modlmisc = {
    &mod_miscops,
    "sun4v memory DR"
};

static struct modlinkage modlinkage = {
    MODREV_1,
    (void *)&modlmisc,
    NULL
};

static int dr_mem_allow_unload = 0;

typedef int (*fn_t)(dr_mem_blk_t *, int *);

/*
 * Global Domain Services (DS) Handle
 */
static ds_svc_hdl_t ds_handle;

/*
 * Supported DS Capability Versions
 */
static ds_ver_t     dr_mem_vers[] = { { 1, 0 } };
#define DR_MEM_NVERS    (sizeof (dr_mem_vers) / sizeof (dr_mem_vers[0]))

/*
 * DS Capability Description
 */
static ds_capability_t dr_mem_cap = {
    DR_MEM_DS_ID,       /* svc_id */
    dr_mem_vers,        /* vers */
    DR_MEM_NVERS        /* nvers */
};

/*
 * DS Callbacks
 */
static void dr_mem_reg_handler(ds_cb_arg_t, ds_ver_t *, ds_svc_hdl_t);
static void dr_mem_unreg_handler(ds_cb_arg_t arg);
static void dr_mem_data_handler(ds_cb_arg_t arg, void *buf, size_t buflen);

/*
 * DS Client Ops Vector
 */
static ds_clnt_ops_t dr_mem_ops = {
    dr_mem_reg_handler, /* ds_reg_cb */
    dr_mem_unreg_handler,   /* ds_unreg_cb */
    dr_mem_data_handler,    /* ds_data_cb */
    NULL            /* cb_arg */
};

/*
 * Operation Results
 *
 * Used internally to gather results while an operation on a
 * list of mblks is in progress. In particular, it is used to
 * keep track of which mblks have already failed so that they are
 * not processed further, and the manner in which they failed.
 */
typedef struct {
    uint64_t    addr;
    uint64_t    size;
    uint32_t    result;
    uint32_t    status;
    char        *string;
} dr_mem_res_t;

static char *
dr_mem_estr[] = {
    "operation succeeded",      /* DR_MEM_RES_OK */
    "operation failed",     /* DR_MEM_RES_FAILURE */
    "operation was blocked",    /* DR_MEM_RES_BLOCKED */
    "memory not defined in MD", /* DR_MEM_RES_NOT_IN_MD */
    "memory already in use",    /* DR_MEM_RES_ESPAN */
    "memory access test failed",    /* DR_MEM_RES_EFAULT */
    "resource not available",   /* DR_MEM_RES_ERESOURCE */
    "permanent pages in span",  /* DR_MEM_RES_PERM */
    "memory span busy",     /* DR_MEM_RES_EBUSY */
    "VM viability test failed", /* DR_MEM_RES_ENOTVIABLE */
    "no pages to unconfigure",  /* DR_MEM_RES_ENOWORK */
    "operation cancelled",      /* DR_MEM_RES_ECANCELLED */
    "operation refused",        /* DR_MEM_RES_EREFUSED */
    "memory span duplicate",    /* DR_MEM_RES_EDUP */
    "invalid argument"      /* DR_MEM_RES_EINVAL */
};

static char *
dr_mem_estr_detail[] = {
    "",                 /* DR_MEM_SRES_NONE */
    "memory DR disabled after migration"    /* DR_MEM_SRES_OS_SUSPENDED */
};

typedef struct {
    kcondvar_t cond;
    kmutex_t lock;
    int error;
    int done;
} mem_sync_t;

/*
 * Internal Functions
 */
static int dr_mem_init(void);
static int dr_mem_fini(void);

static int dr_mem_list_wrk(dr_mem_hdr_t *, dr_mem_hdr_t **, int *);
static int dr_mem_list_query(dr_mem_hdr_t *, dr_mem_hdr_t **, int *);
static int dr_mem_del_stat(dr_mem_hdr_t *, dr_mem_hdr_t **, int *);
static int dr_mem_del_cancel(dr_mem_hdr_t *, dr_mem_hdr_t **, int *);

static int dr_mem_unconfigure(dr_mem_blk_t *, int *);
static int dr_mem_configure(dr_mem_blk_t *, int *);
static void dr_mem_query(dr_mem_blk_t *, dr_mem_query_t *);

static dr_mem_res_t *dr_mem_res_array_init(dr_mem_hdr_t *, drctl_rsrc_t *, int);
static void dr_mem_res_array_fini(dr_mem_res_t *res, int nres);
static size_t dr_mem_pack_response(dr_mem_hdr_t *req, dr_mem_res_t *res,
    dr_mem_hdr_t **respp);

static int dr_mem_find(dr_mem_blk_t *mbp);
static mde_cookie_t dr_mem_find_node_md(dr_mem_blk_t *, md_t *, mde_cookie_t *);

static int mem_add(pfn_t, pgcnt_t);
static int mem_del(pfn_t, pgcnt_t);

extern int kphysm_add_memory_dynamic(pfn_t, pgcnt_t);

int
_init(void)
{
    int status;

    /* check that Memory DR is enabled */
    if (dr_is_disabled(DR_TYPE_MEM))
        return (ENOTSUP);

    if ((status = dr_mem_init()) != 0) {
        cmn_err(CE_NOTE, "Memory DR initialization failed");
        return (status);
    }

    if ((status = mod_install(&modlinkage)) != 0) {
        (void) dr_mem_fini();
    }

    return (status);
}

int
_info(struct modinfo *modinfop)
{
    return (mod_info(&modlinkage, modinfop));
}

int
_fini(void)
{
    int status;

    if (dr_mem_allow_unload == 0)
        return (EBUSY);

    if ((status = mod_remove(&modlinkage)) == 0) {
        (void) dr_mem_fini();
    }

    return (status);
}

static int
dr_mem_init(void)
{
    int rv;

    if ((rv = ds_cap_init(&dr_mem_cap, &dr_mem_ops)) != 0) {
        cmn_err(CE_NOTE, "dr_mem: ds_cap_init failed: %d", rv);
        return (rv);
    }

    return (0);
}

static int
dr_mem_fini(void)
{
    int rv;

    if ((rv = ds_cap_fini(&dr_mem_cap)) != 0) {
        cmn_err(CE_NOTE, "dr_mem: ds_cap_fini failed: %d", rv);
    }

    return (rv);
}

static void
dr_mem_reg_handler(ds_cb_arg_t arg, ds_ver_t *ver, ds_svc_hdl_t hdl)
{
    DR_DBG_MEM("reg_handler: arg=0x%p, ver=%d.%d, hdl=0x%lx\n", arg,
        ver->major, ver->minor, hdl);

    ds_handle = hdl;
}

static void
dr_mem_unreg_handler(ds_cb_arg_t arg)
{
    DR_DBG_MEM("unreg_handler: arg=0x%p\n", arg);

    ds_handle = DS_INVALID_HDL;
}

/*ARGSUSED*/
static void
dr_mem_data_handler(ds_cb_arg_t arg, void *buf, size_t buflen)
{
    dr_mem_hdr_t    *req = buf;
    dr_mem_hdr_t    err_resp;
    dr_mem_hdr_t    *resp = &err_resp;
    int     resp_len = 0;
    int     rv = EINVAL;

    /*
     * Sanity check the message
     */
    if (buflen < sizeof (dr_mem_hdr_t)) {
        DR_DBG_MEM("incoming message short: expected at least %ld "
            "bytes, received %ld\n", sizeof (dr_mem_hdr_t), buflen);
        goto done;
    }

    if (req == NULL) {
        DR_DBG_MEM("empty message: expected at least %ld bytes\n",
            sizeof (dr_mem_hdr_t));
        goto done;
    }

    DR_DBG_MEM("incoming request:\n");
    DR_DBG_DUMP_MSG(buf, buflen);

    /*
     * Process the command
     */
    switch (req->msg_type) {
    case DR_MEM_CONFIGURE:
    case DR_MEM_UNCONFIGURE:
        if (req->msg_arg == 0) {
            DR_DBG_MEM("No mblks specified for operation\n");
            goto done;
        }
        if ((rv = dr_mem_list_wrk(req, &resp, &resp_len)) != 0) {
            DR_DBG_MEM("%s failed (%d)\n",
                (req->msg_type == DR_MEM_CONFIGURE) ?
                "Memory configure" : "Memory unconfigure", rv);
        }
        break;

    case DR_MEM_UNCONF_STATUS:
        if ((rv = dr_mem_del_stat(req, &resp, &resp_len)) != 0)
            DR_DBG_MEM("Memory delete status failed (%d)\n", rv);
        break;

    case DR_MEM_UNCONF_CANCEL:
        if ((rv = dr_mem_del_cancel(req, &resp, &resp_len)) != 0)
            DR_DBG_MEM("Memory delete cancel failed (%d)\n", rv);
        break;

    case DR_MEM_QUERY:
        if (req->msg_arg == 0) {
            DR_DBG_MEM("No mblks specified for operation\n");
            goto done;
        }
        if ((rv = dr_mem_list_query(req, &resp, &resp_len)) != 0)
            DR_DBG_MEM("Memory query failed (%d)\n", rv);
        break;

    default:
        cmn_err(CE_NOTE, "unsupported memory DR operation (%d)",
            req->msg_type);
        break;
    }

done:
    /* check if an error occurred */
    if (resp == &err_resp) {
        resp->req_num = (req) ? req->req_num : 0;
        resp->msg_type = DR_MEM_ERROR;
        resp->msg_arg = rv;
        resp_len = sizeof (dr_mem_hdr_t);
    }

    DR_DBG_MEM("outgoing response:\n");
    DR_DBG_DUMP_MSG(resp, resp_len);

    /* send back the response */
    if (ds_cap_send(ds_handle, resp, resp_len) != 0) {
        DR_DBG_MEM("ds_send failed\n");
    }

    /* free any allocated memory */
    if (resp != &err_resp) {
        kmem_free(resp, resp_len);
    }
}

static char *
dr_mem_get_errstr(int result, int subresult)
{
    size_t len;
    char *errstr;
    const char *separator = ": ";

    if (subresult == DR_MEM_SRES_NONE)
        return (i_ddi_strdup(dr_mem_estr[result], KM_SLEEP));

    len = snprintf(NULL, 0, "%s%s%s", dr_mem_estr[result],
        separator, dr_mem_estr_detail[subresult]) + 1;

    errstr = kmem_alloc(len, KM_SLEEP);

    (void) snprintf(errstr, len, "%s%s%s", dr_mem_estr[result],
        separator, dr_mem_estr_detail[subresult]);

    return (errstr);
}

/*
 * Common routine to config or unconfig multiple mblks.
 *
 * Note: Do not modify result buffer or length on error.
 */
static int
dr_mem_list_wrk(dr_mem_hdr_t *req, dr_mem_hdr_t **resp, int *resp_len)
{
    int     rv;
    int     idx;
    int     count;
    int     result;
    int     subresult;
    int     status;
    boolean_t   suspend_allows_dr;
    fn_t        dr_fn;
    int     se_hint;
    dr_mem_blk_t    *req_mblks;
    dr_mem_res_t    *res;
    int     drctl_cmd;
    int     drctl_flags = 0;
    drctl_rsrc_t    *drctl_req;
    size_t      drctl_req_len;
    drctl_resp_t    *drctl_resp;
    drctl_rsrc_t    *drctl_rsrc;
    size_t      drctl_resp_len = 0;
    drctl_cookie_t  drctl_res_ck;

    ASSERT((req != NULL) && (req->msg_arg != 0));

    count = req->msg_arg;

    /*
     * Extract all information that is specific
     * to the various types of operations.
     */
    switch (req->msg_type) {
    case DR_MEM_CONFIGURE:
        dr_fn = dr_mem_configure;
        drctl_cmd = DRCTL_MEM_CONFIG_REQUEST;
        se_hint = SE_HINT_INSERT;
        break;
    case DR_MEM_UNCONFIGURE:
        dr_fn = dr_mem_unconfigure;
        drctl_cmd = DRCTL_MEM_UNCONFIG_REQUEST;
        se_hint = SE_HINT_REMOVE;
        break;
    default:
        /* Programming error if we reach this. */
        cmn_err(CE_NOTE, "%s: bad msg_type %d\n",
            __func__, req->msg_type);
        ASSERT(0);
        return (-1);
    }

    /* the incoming array of mblks to operate on */
    req_mblks = DR_MEM_CMD_MBLKS(req);

    /* allocate drctl request msg based on incoming resource count */
    drctl_req_len = sizeof (drctl_rsrc_t) * count;
    drctl_req = kmem_zalloc(drctl_req_len, KM_SLEEP);

    /* copy the size for the drctl call from the incoming request msg */
    for (idx = 0; idx < count; idx++) {
        drctl_req[idx].res_mem_addr = req_mblks[idx].addr;
        drctl_req[idx].res_mem_size = req_mblks[idx].size;
    }

    rv = drctl_config_init(drctl_cmd, drctl_flags, drctl_req,
        count, &drctl_resp, &drctl_resp_len, &drctl_res_ck);

    ASSERT((drctl_resp != NULL) && (drctl_resp_len != 0));

    if (rv != 0) {
        DR_DBG_MEM("%s: drctl_config_init returned: %d\n",
            __func__, rv);
        kmem_free(drctl_resp, drctl_resp_len);
        kmem_free(drctl_req, drctl_req_len);
        return (rv);
    }

    ASSERT(drctl_resp->resp_type == DRCTL_RESP_OK);

    drctl_rsrc = drctl_resp->resp_resources;

    /* create the result scratch array */
    res = dr_mem_res_array_init(req, drctl_rsrc, count);

    /*
     * Memory DR operations are not safe if we have been suspended and
     * resumed. Until this limitation is lifted, check to see if memory
     * DR operations are permitted at this time by the suspend subsystem.
     */
    if ((suspend_allows_dr = suspend_memdr_allowed()) == B_FALSE) {
        result = DR_MEM_RES_BLOCKED;
        subresult = DR_MEM_SRES_OS_SUSPENDED;
    } else {
        subresult = DR_MEM_SRES_NONE;
    }

    /* perform the specified operation on each of the mblks */
    for (idx = 0; idx < count; idx++) {
        /*
         * If no action will be taken against the current
         * mblk, update the drctl resource information to
         * ensure that it gets recovered properly during
         * the drctl fini() call.
         */
        if (res[idx].result != DR_MEM_RES_OK) {
            drctl_req[idx].status = DRCTL_STATUS_CONFIG_FAILURE;
            continue;
        }

        /*
         * If memory DR operations are permitted at this time by
         * the suspend subsystem, call the function to perform the
         * operation, otherwise return a result indicating that the
         * operation was blocked.
         */
        if (suspend_allows_dr)
            result = (*dr_fn)(&req_mblks[idx], &status);

        /* save off results of the operation */
        res[idx].result = result;
        res[idx].status = status;
        res[idx].addr = req_mblks[idx].addr;    /* for partial case */
        res[idx].size = req_mblks[idx].size;    /* for partial case */
        res[idx].string = dr_mem_get_errstr(result, subresult);

        /* save result for drctl fini() reusing init() msg memory */
        drctl_req[idx].status = (result != DR_MEM_RES_OK) ?
            DRCTL_STATUS_CONFIG_FAILURE : DRCTL_STATUS_CONFIG_SUCCESS;

        DR_DBG_MEM("%s: mblk 0x%lx.0x%lx stat %d result %d off '%s'\n",
            __func__, req_mblks[idx].addr, req_mblks[idx].size,
            drctl_req[idx].status, result,
            (res[idx].string) ? res[idx].string : "");
    }

    if ((rv = drctl_config_fini(&drctl_res_ck, drctl_req, count)) != 0)
        DR_DBG_MEM("%s: drctl_config_fini returned: %d\n",
            __func__, rv);

    /*
     * Operation completed without any fatal errors.
     * Pack the response for transmission.
     */
    *resp_len = dr_mem_pack_response(req, res, resp);

    /* notify interested parties about the operation */
    dr_generate_event(DR_TYPE_MEM, se_hint);

    /*
     * Deallocate any scratch memory.
     */
    kmem_free(drctl_resp, drctl_resp_len);
    kmem_free(drctl_req, drctl_req_len);

    dr_mem_res_array_fini(res, count);

    return (0);
}

/*
 * Allocate and initialize a result array based on the initial
 * drctl operation. A valid result array is always returned.
 */
static dr_mem_res_t *
dr_mem_res_array_init(dr_mem_hdr_t *req, drctl_rsrc_t *rsrc, int nrsrc)
{
    int     idx;
    dr_mem_res_t    *res;
    char        *err_str;
    size_t      err_len;

    /* allocate zero filled buffer to initialize fields */
    res = kmem_zalloc(nrsrc * sizeof (dr_mem_res_t), KM_SLEEP);

    /*
     * Fill in the result information for each resource.
     */
    for (idx = 0; idx < nrsrc; idx++) {
        res[idx].addr = rsrc[idx].res_mem_addr;
        res[idx].size = rsrc[idx].res_mem_size;
        res[idx].result = DR_MEM_RES_OK;

        if (rsrc[idx].status == DRCTL_STATUS_ALLOW)
            continue;

        /*
         * Update the state information for this mblk.
         */
        res[idx].result = DR_MEM_RES_BLOCKED;
        res[idx].status = (req->msg_type == DR_MEM_CONFIGURE) ?
            DR_MEM_STAT_UNCONFIGURED : DR_MEM_STAT_CONFIGURED;

        /*
         * If an error string exists, copy it out of the
         * message buffer. This eliminates any dependency
         * on the memory allocated for the message buffer
         * itself.
         */
        if (rsrc[idx].offset != NULL) {
            err_str = (char *)rsrc + rsrc[idx].offset;
            err_len = strlen(err_str) + 1;

            res[idx].string = kmem_alloc(err_len, KM_SLEEP);
            bcopy(err_str, res[idx].string, err_len);
        }
    }

    return (res);
}

static void
dr_mem_res_array_fini(dr_mem_res_t *res, int nres)
{
    int idx;
    size_t  str_len;

    for (idx = 0; idx < nres; idx++) {
        /* deallocate the error string if present */
        if (res[idx].string) {
            str_len = strlen(res[idx].string) + 1;
            kmem_free(res[idx].string, str_len);
        }
    }

    /* deallocate the result array itself */
    kmem_free(res, sizeof (dr_mem_res_t) * nres);
}

/*
 * Allocate and pack a response message for transmission based
 * on the specified result array. A valid response message and
 * valid size information is always returned.
 */
static size_t
dr_mem_pack_response(dr_mem_hdr_t *req, dr_mem_res_t *res, dr_mem_hdr_t **respp)
{
    int     idx;
    dr_mem_hdr_t    *resp;
    dr_mem_stat_t   *resp_stat;
    size_t      resp_len;
    uint32_t    curr_off;
    caddr_t     curr_str;
    size_t      str_len;
    size_t      stat_len;
    int     nstat = req->msg_arg;

    /*
     * Calculate the size of the response message
     * and allocate an appropriately sized buffer.
     */
    resp_len = sizeof (dr_mem_hdr_t);

    /* add the stat array size */
    stat_len = sizeof (dr_mem_stat_t) * nstat;
    resp_len += stat_len;

    /* add the size of any error strings */
    for (idx = 0; idx < nstat; idx++) {
        if (res[idx].string != NULL) {
            resp_len += strlen(res[idx].string) + 1;
        }
    }

    /* allocate the message buffer */
    resp = kmem_zalloc(resp_len, KM_SLEEP);

    /*
     * Fill in the header information.
     */
    resp->req_num = req->req_num;
    resp->msg_type = DR_MEM_OK;
    resp->msg_arg = nstat;

    /*
     * Fill in the stat information.
     */
    resp_stat = DR_MEM_RESP_STATS(resp);

    /* string offsets start immediately after stat array */
    curr_off = sizeof (dr_mem_hdr_t) + stat_len;
    curr_str = (char *)resp_stat + stat_len;

    for (idx = 0; idx < nstat; idx++) {
        resp_stat[idx].addr = res[idx].addr;
        resp_stat[idx].size = res[idx].size;
        resp_stat[idx].result = res[idx].result;
        resp_stat[idx].status = res[idx].status;

        if (res[idx].string != NULL) {
            /* copy over the error string */
            str_len = strlen(res[idx].string) + 1;
            bcopy(res[idx].string, curr_str, str_len);
            resp_stat[idx].string_off = curr_off;

            curr_off += str_len;
            curr_str += str_len;
        }
    }

    /* buffer should be exactly filled */
    ASSERT(curr_off == resp_len);

    *respp = resp;
    return (resp_len);
}

static void
dr_mem_query(dr_mem_blk_t *mbp, dr_mem_query_t *mqp)
{
    memquery_t mq;

    DR_DBG_MEM("dr_mem_query...\n");


    (void) kphysm_del_span_query(btop(mbp->addr), btop(mbp->size), &mq);

    if (!mq.phys_pages)
        return;

    mqp->addr = mbp->addr;
    mqp->mq.phys_pages = ptob(mq.phys_pages);
    mqp->mq.managed = ptob(mq.managed);
    mqp->mq.nonrelocatable = ptob(mq.nonrelocatable);
    mqp->mq.first_nonrelocatable = ptob(mq.first_nonrelocatable);
    mqp->mq.last_nonrelocatable = ptob(mq.last_nonrelocatable);
    /*
     * Set to the max byte offset within the page.
     */
    if (mqp->mq.nonrelocatable)
        mqp->mq.last_nonrelocatable += PAGESIZE - 1;
}

/*
 * Do not modify result buffer or length on error.
 */
static int
dr_mem_list_query(dr_mem_hdr_t *req, dr_mem_hdr_t **resp, int *resp_len)
{
    int     idx;
    int     rlen;
    int     nml;
    struct memlist  *ml;
    struct memlist  *phys_copy = NULL;
    dr_mem_blk_t    *req_mblks, mb;
    dr_mem_hdr_t    *rp;
    dr_mem_query_t  *stat;

    drctl_block();

    /* the incoming array of req_mblks to configure */
    req_mblks = DR_MEM_CMD_MBLKS(req);

    /* allocate a response message, should be freed by caller */
    nml = 0;
    rlen = sizeof (dr_mem_hdr_t);
    if (req_mblks->addr == NULL && req_mblks->size == 0) {
        /*
         * Request is for domain's full view of it's memory.
         * place a copy in phys_copy then release the memlist lock.
         */
        memlist_read_lock();
        phys_copy = dr_memlist_dup(phys_install);
        memlist_read_unlock();

        for (ml = phys_copy; ml; ml = ml->ml_next)
            nml++;

        rlen += nml * sizeof (dr_mem_query_t);
    } else {
        rlen += req->msg_arg * sizeof (dr_mem_query_t);
    }
    rp = kmem_zalloc(rlen, KM_SLEEP);

    /* fill in the known data */
    rp->req_num = req->req_num;
    rp->msg_type = DR_MEM_OK;
    rp->msg_arg = nml ? nml : req->msg_arg;

    /* stat array for the response */
    stat = DR_MEM_RESP_QUERY(rp);

    /* get the status for each of the mblocks */
    if (nml) {
        for (idx = 0, ml = phys_copy; ml; ml = ml->ml_next, idx++) {
            mb.addr = ml->ml_address;
            mb.size = ml->ml_size;
            dr_mem_query(&mb, &stat[idx]);
        }
    } else {
        for (idx = 0; idx < req->msg_arg; idx++)
            dr_mem_query(&req_mblks[idx], &stat[idx]);
    }

    *resp = rp;
    *resp_len = rlen;
    if (phys_copy != NULL) {
        dr_memlist_delete(phys_copy);
    }
    drctl_unblock();

    return (0);
}

static int
cvt_err(int err)
{
    int rv;

    switch (err) {
    case KPHYSM_OK:
        rv = DR_MEM_RES_OK;
        break;
    case KPHYSM_ESPAN:
        rv = DR_MEM_RES_ESPAN;
        break;
    case KPHYSM_EFAULT:
        rv = DR_MEM_RES_EFAULT;
        break;
    case KPHYSM_ERESOURCE:
        rv = DR_MEM_RES_ERESOURCE;
        break;
    case KPHYSM_ENOTSUP:
    case KPHYSM_ENOHANDLES:
        rv = DR_MEM_RES_FAILURE;
        break;
    case KPHYSM_ENONRELOC:
        rv = DR_MEM_RES_PERM;
        break;
    case KPHYSM_EHANDLE:
        rv = DR_MEM_RES_FAILURE;
        break;
    case KPHYSM_EBUSY:
        rv = DR_MEM_RES_EBUSY;
        break;
    case KPHYSM_ENOTVIABLE:
        rv = DR_MEM_RES_ENOTVIABLE;
        break;
    case KPHYSM_ESEQUENCE:
        rv = DR_MEM_RES_FAILURE;
        break;
    case KPHYSM_ENOWORK:
        rv = DR_MEM_RES_ENOWORK;
        break;
    case KPHYSM_ECANCELLED:
        rv = DR_MEM_RES_ECANCELLED;
        break;
    case KPHYSM_EREFUSED:
        rv = DR_MEM_RES_EREFUSED;
        break;
    case KPHYSM_ENOTFINISHED:
    case KPHYSM_ENOTRUNNING:
        rv = DR_MEM_RES_FAILURE;
        break;
    case KPHYSM_EDUP:
        rv = DR_MEM_RES_EDUP;
        break;
    default:
        rv = DR_MEM_RES_FAILURE;
        break;
    }

    return (rv);
}

static int
dr_mem_configure(dr_mem_blk_t *mbp, int *status)
{
    int rv;
    uint64_t addr, size;

    rv = 0;
    addr = mbp->addr;
    size = mbp->size;

    DR_DBG_MEM("dr_mem_configure...\n");

    if (!MBLK_IS_VALID(mbp)) {
        DR_DBG_MEM("invalid mblk 0x%lx.0x%lx\n", addr, size);
        *status = DR_MEM_STAT_UNCONFIGURED;
        rv = DR_MEM_RES_EINVAL;
    } else if (rv = dr_mem_find(mbp)) {
        DR_DBG_MEM("failed to find mblk 0x%lx.0x%lx (%d)\n",
            addr, size, rv);
        if (rv == EINVAL) {
            *status = DR_MEM_STAT_NOT_PRESENT;
            rv = DR_MEM_RES_NOT_IN_MD;
        } else {
            *status = DR_MEM_STAT_UNCONFIGURED;
            rv = DR_MEM_RES_FAILURE;
        }
    } else {
        rv = mem_add(btop(addr), btop(size));
        DR_DBG_MEM("addr=0x%lx size=0x%lx rv=%d\n", addr, size, rv);
        if (rv) {
            *status = DR_MEM_STAT_UNCONFIGURED;
        } else {
            *status = DR_MEM_STAT_CONFIGURED;
        }
    }

    return (rv);
}

static int
dr_mem_unconfigure(dr_mem_blk_t *mbp, int *status)
{
    int rv;

    DR_DBG_MEM("dr_mem_unconfigure...\n");

    if (!MBLK_IS_VALID(mbp)) {
        DR_DBG_MEM("invalid mblk 0x%lx.0x%lx\n",
            mbp->addr, mbp->size);
            *status = DR_MEM_STAT_CONFIGURED;
            rv = DR_MEM_RES_EINVAL;
    } else if (rv = mem_del(btop(mbp->addr), btop(mbp->size))) {
        *status = DR_MEM_STAT_CONFIGURED;
    } else {
        *status = DR_MEM_STAT_UNCONFIGURED;
        rv = DR_MEM_RES_OK;
        DR_DBG_MEM("mblk 0x%lx.0x%lx unconfigured\n",
            mbp->addr, mbp->size);
    }
    return (rv);
}

static int
dr_mem_del_stat(dr_mem_hdr_t *req, dr_mem_hdr_t **resp, int *resp_len)
{
    int         status;
    int         rlen;
    memdelstat_t        del_stat, *stat;
    dr_mem_hdr_t        *rp;

    /*
     * If a mem delete is in progress, get its status.
     */
    status = (dr_mh && (kphysm_del_status(dr_mh, &del_stat) == KPHYSM_OK));

    /* allocate a response message, should be freed by caller */
    rlen = sizeof (dr_mem_hdr_t);
    rlen += status * sizeof (memdelstat_t);
    rp = kmem_zalloc(rlen, KM_SLEEP);

    /* fill in the known data */
    rp->req_num = req->req_num;
    rp->msg_type = DR_MEM_OK;
    rp->msg_arg = status;

    if (status) {
        /* stat struct for the response */
        stat = DR_MEM_RESP_DEL_STAT(rp);
        stat->phys_pages = ptob(del_stat.phys_pages);
        stat->managed = ptob(del_stat.managed);
        stat->collected = ptob(del_stat.collected);
    }

    *resp = rp;
    *resp_len = rlen;

    return (0);
}

static int
dr_mem_del_cancel(dr_mem_hdr_t *req, dr_mem_hdr_t **resp, int *resp_len)
{
    int     rlen;
    dr_mem_hdr_t    *rp;

    /* allocate a response message, should be freed by caller */
    rlen = sizeof (dr_mem_hdr_t);
    rp = kmem_zalloc(rlen, KM_SLEEP);

    /* fill in the known data */
    rp->req_num = req->req_num;
    rp->msg_type = DR_MEM_OK;
    rp->msg_arg = (dr_mh && kphysm_del_cancel(dr_mh) != KPHYSM_OK) ?
        DR_MEM_RES_EINVAL : DR_MEM_RES_OK;

    *resp = rp;
    *resp_len = rlen;

    return (0);
}

static int
dr_mem_find(dr_mem_blk_t *mbp)
{
    md_t        *mdp = NULL;
    int     num_nodes;
    int     rv = 0;
    int     listsz;
    mde_cookie_t    *listp = NULL;
    mde_cookie_t    memnode;
    char        *found = "found";

    if ((mdp = md_get_handle()) == NULL) {
        DR_DBG_MEM("unable to initialize machine description\n");
        return (-1);
    }

    num_nodes = md_node_count(mdp);
    ASSERT(num_nodes > 0);

    listsz = num_nodes * sizeof (mde_cookie_t);
    listp = kmem_zalloc(listsz, KM_SLEEP);

    memnode = dr_mem_find_node_md(mbp, mdp, listp);

    if (memnode == MDE_INVAL_ELEM_COOKIE) {
        rv = EINVAL;
        found = "not found";
    }

    DR_DBG_MEM("mblk 0x%lx.0x%lx %s\n", mbp->addr, mbp->size, found);

    kmem_free(listp, listsz);
    (void) md_fini_handle(mdp);

    return (rv);
}

/*
 * Look up a particular mblk in the MD. Returns the mde_cookie_t
 * representing that mblk if present, and MDE_INVAL_ELEM_COOKIE
 * otherwise. It is assumed the scratch array has already been
 * allocated so that it can accommodate the worst case scenario,
 * every node in the MD.
 */
static mde_cookie_t
dr_mem_find_node_md(dr_mem_blk_t *mbp, md_t *mdp, mde_cookie_t *listp)
{
    int     idx;
    int     nnodes;
    mde_cookie_t    rootnode;
    uint64_t    base_prop;
    uint64_t    size_prop;
    mde_cookie_t    result = MDE_INVAL_ELEM_COOKIE;

    rootnode = md_root_node(mdp);
    ASSERT(rootnode != MDE_INVAL_ELEM_COOKIE);

    /*
     * Scan the DAG for all the mem nodes
     */
    nnodes = md_scan_dag(mdp, rootnode, md_find_name(mdp, "mblock"),
        md_find_name(mdp, "fwd"), listp);

    if (nnodes < 0) {
        DR_DBG_MEM("Scan for mblks failed\n");
        return (result);
    }

    DR_DBG_MEM("dr_mem_find_node_md: found %d mblks in the MD\n", nnodes);

    /*
     * Find the mblk of interest
     */
    for (idx = 0; idx < nnodes; idx++) {

        if (md_get_prop_val(mdp, listp[idx], "base", &base_prop)) {
            DR_DBG_MEM("Missing 'base' property for mblk node %d\n",
                idx);
            break;
        }

        if (md_get_prop_val(mdp, listp[idx], "size", &size_prop)) {
            DR_DBG_MEM("Missing 'size' property for mblk node %d\n",
                idx);
            break;
        }

        if (base_prop <= mbp->addr &&
            (base_prop + size_prop) >= (mbp->addr + mbp->size)) {
            /* found a match */
            DR_DBG_MEM("dr_mem_find_node_md: found mblk "
                "0x%lx.0x%lx in MD\n", mbp->addr, mbp->size);
            result = listp[idx];
            break;
        }
    }

    if (result == MDE_INVAL_ELEM_COOKIE) {
        DR_DBG_MEM("mblk 0x%lx.0x%lx not in MD\n",
            mbp->addr, mbp->size);
    }

    return (result);
}

static int
mem_add(pfn_t base, pgcnt_t npgs)
{
    int rv, rc;

    DR_DBG_MEM("%s: begin base=0x%lx npgs=0x%lx\n", __func__, base, npgs);

    if (npgs == 0)
        return (DR_MEM_RES_OK);

    rv = kphysm_add_memory_dynamic(base, npgs);
    DR_DBG_MEM("%s: kphysm_add(0x%lx, 0x%lx) = %d", __func__, base, npgs,
        rv);
    if (rv == KPHYSM_OK) {
        if (rc = kcage_range_add(base, npgs, KCAGE_DOWN))
            cmn_err(CE_WARN, "kcage_range_add() = %d", rc);
    }
    rv = cvt_err(rv);
    return (rv);
}

static void
del_done(void *arg, int error)
{
    mem_sync_t *ms = arg;

    mutex_enter(&ms->lock);
    ms->error = error;
    ms->done = 1;
    cv_signal(&ms->cond);
    mutex_exit(&ms->lock);
}

static int
mem_del(pfn_t base, pgcnt_t npgs)
{
    int rv, err, del_range = 0;
    int convert = 1;
    mem_sync_t ms;
    memquery_t mq;
    memhandle_t mh;
    struct memlist *ml;
    struct memlist *d_ml = NULL;

    DR_DBG_MEM("%s: begin base=0x%lx npgs=0x%lx\n", __func__, base, npgs);

    if (npgs == 0)
        return (DR_MEM_RES_OK);

    if ((rv = kphysm_del_gethandle(&mh)) != KPHYSM_OK) {
        cmn_err(CE_WARN, "%s: del_gethandle() = %d", __func__, rv);
        rv = cvt_err(rv);
        return (rv);
    }
    if ((rv = kphysm_del_span_query(base, npgs, &mq))
        != KPHYSM_OK) {
        cmn_err(CE_WARN, "%s: del_span_query() = %d", __func__, rv);
        goto done;
    }
    if (mq.nonrelocatable) {
        DR_DBG_MEM("%s: non-reloc pages = %ld",
            __func__, mq.nonrelocatable);
        rv  = KPHYSM_ENONRELOC;
        goto done;
    }
    if (rv = kcage_range_delete(base, npgs)) {
        switch (rv) {
        case EBUSY:
            rv = DR_MEM_RES_ENOTVIABLE;
            break;
        default:
            rv = DR_MEM_RES_FAILURE;
            break;
        }
        convert = 0; /* conversion done */
        cmn_err(CE_WARN, "%s: del_range() = %d", __func__, rv);
        goto done;
    } else {
        del_range++;
    }
    if ((rv = kphysm_del_span(mh, base, npgs)) != KPHYSM_OK) {
        cmn_err(CE_WARN, "%s: del_span() = %d", __func__, rv);
        goto done;
    }
    if ((rv = memlist_add_span(ptob(base), ptob(npgs), &d_ml))
        != MEML_SPANOP_OK) {
        switch (rv) {
        case MEML_SPANOP_ESPAN:
            rv = DR_MEM_RES_ESPAN;
            break;
        case MEML_SPANOP_EALLOC:
            rv = DR_MEM_RES_ERESOURCE;
            break;
        default:
            rv = DR_MEM_RES_FAILURE;
            break;
        }
        convert = 0; /* conversion done */
        cmn_err(CE_WARN, "%s: add_span() = %d", __func__, rv);
        goto done;
    }

    DR_DBG_MEM("%s: reserved=0x%lx", __func__, npgs);

    bzero((void *) &ms, sizeof (ms));

    mutex_init(&ms.lock, NULL, MUTEX_DRIVER, NULL);
    cv_init(&ms.cond, NULL, CV_DRIVER, NULL);
    mutex_enter(&ms.lock);

    if ((rv = kphysm_del_start(mh, del_done, (void *) &ms)) == KPHYSM_OK) {
        /*
         * Since we've called drctl_config_init, we are the only
         * DR ctl operation in progress.  Set dr_mh to the
         * delete memhandle for use by stat and cancel.
         */
        ASSERT(dr_mh == NULL);
        dr_mh = mh;

        /*
         * Wait for completion or interrupt.
         */
        while (!ms.done) {
            if (cv_wait_sig(&ms.cond, &ms.lock) == 0) {
                /*
                 * There is a pending signal.
                 */
                (void) kphysm_del_cancel(mh);
                DR_DBG_MEM("%s: cancel", __func__);
                /*
                 * Wait for completion.
                 */
                while (!ms.done)
                    cv_wait(&ms.cond, &ms.lock);
            }
        }
        dr_mh = NULL;
        rv = ms.error;
    } else {
        DR_DBG_MEM("%s: del_start() = %d", __func__, rv);
    }

    mutex_exit(&ms.lock);
    cv_destroy(&ms.cond);
    mutex_destroy(&ms.lock);

done:
    if (rv && del_range) {
        /*
         * Add back the spans to the kcage growth list.
         */
        for (ml = d_ml; ml; ml = ml->ml_next)
            if (err = kcage_range_add(btop(ml->ml_address),
                btop(ml->ml_size), KCAGE_DOWN))
                cmn_err(CE_WARN, "kcage_range_add() = %d", err);
    }
    memlist_free_list(d_ml);

    if ((err = kphysm_del_release(mh)) != KPHYSM_OK)
        cmn_err(CE_WARN, "%s: del_release() = %d", __func__, err);
    if (convert)
        rv = cvt_err(rv);

    DR_DBG_MEM("%s: rv=%d", __func__, rv);

    return (rv);
}