/*
 * Copyright (C) 2009      Citrix Ltd.
 * Author Vincent Hanquez <vincent.hanquez@eu.citrix.com>
 * Author Stefano Stabellini <stefano.stabellini@eu.citrix.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published
 * by the Free Software Foundation; version 2.1 only. with the special
 * exception on linking described in file LICENSE.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 */

#include "libxl_osdeps.h" /* must come before any other headers */

#include "libxl_internal.h"

#define PCI_BDF                "%04x:%02x:%02x.%01x"
#define PCI_BDF_SHORT          "%02x:%02x.%01x"
#define PCI_BDF_VDEVFN         "%04x:%02x:%02x.%01x@%02x"
#define PCI_OPTIONS            "msitranslate=%d,power_mgmt=%d"
#define PCI_BDF_XSPATH         "%04x-%02x-%02x-%01x"

static unsigned int pcidev_encode_bdf(libxl_device_pci *pcidev)
{
    unsigned int value;

    value = pcidev->domain << 16;
    value |= (pcidev->bus & 0xff) << 8;
    value |= (pcidev->dev & 0x1f) << 3;
    value |= (pcidev->func & 0x7);

    return value;
}

static int pcidev_struct_fill(libxl_device_pci *pcidev, unsigned int domain,
                               unsigned int bus, unsigned int dev,
                               unsigned int func, unsigned int vdevfn)
{
    pcidev->domain = domain;
    pcidev->bus = bus;
    pcidev->dev = dev;
    pcidev->func = func;
    pcidev->vdevfn = vdevfn;
    return 0;
}

static void libxl_create_pci_backend_device(libxl__gc *gc, flexarray_t *back, int num, libxl_device_pci *pcidev)
{
    flexarray_append(back, libxl__sprintf(gc, "key-%d", num));
    flexarray_append(back, libxl__sprintf(gc, PCI_BDF, pcidev->domain, pcidev->bus, pcidev->dev, pcidev->func));
    flexarray_append(back, libxl__sprintf(gc, "dev-%d", num));
    flexarray_append(back, libxl__sprintf(gc, PCI_BDF, pcidev->domain, pcidev->bus, pcidev->dev, pcidev->func));
    if (pcidev->vdevfn)
        flexarray_append_pair(back, libxl__sprintf(gc, "vdevfn-%d", num), libxl__sprintf(gc, "%x", pcidev->vdevfn));
    flexarray_append(back, libxl__sprintf(gc, "opts-%d", num));
    flexarray_append(back,
              libxl__sprintf(gc, "msitranslate=%d,power_mgmt=%d,permissive=%d",
                             pcidev->msitranslate, pcidev->power_mgmt,
                             pcidev->permissive));
    flexarray_append_pair(back, libxl__sprintf(gc, "state-%d", num), libxl__sprintf(gc, "%d", 1));
}

int libxl__create_pci_backend(libxl__gc *gc, uint32_t domid,
                              libxl_device_pci *pcidev, int num)
{
    libxl_ctx *ctx = libxl__gc_owner(gc);
    flexarray_t *front = NULL;
    flexarray_t *back = NULL;
    libxl__device device;
    int ret = ERROR_NOMEM, i;

    front = flexarray_make(gc, 16, 1);
    back = flexarray_make(gc, 16, 1);

    ret = 0;

    LIBXL__LOG(ctx, LIBXL__LOG_DEBUG, "Creating pci backend");

    /* add pci device */
    device.backend_devid = 0;
    device.backend_domid = 0;
    device.backend_kind = LIBXL__DEVICE_KIND_PCI;
    device.devid = 0;
    device.domid = domid;
    device.kind = LIBXL__DEVICE_KIND_PCI;

    flexarray_append_pair(back, "frontend-id", libxl__sprintf(gc, "%d", domid));
    flexarray_append_pair(back, "online", "1");
    flexarray_append_pair(back, "state", libxl__sprintf(gc, "%d", 1));
    flexarray_append_pair(back, "domain", libxl__domid_to_name(gc, domid));

    for (i = 0; i < num; i++, pcidev++)
        libxl_create_pci_backend_device(gc, back, i, pcidev);

    flexarray_append_pair(back, "num_devs", libxl__sprintf(gc, "%d", num));
    flexarray_append_pair(front, "backend-id", libxl__sprintf(gc, "%d", 0));
    flexarray_append_pair(front, "state", libxl__sprintf(gc, "%d", 1));

    libxl__device_generic_add(gc, XBT_NULL, &device,
                              libxl__xs_kvs_of_flexarray(gc, back, back->count),
                              libxl__xs_kvs_of_flexarray(gc, front, front->count),
                              NULL);

    return 0;
}

static int libxl__device_pci_add_xenstore(libxl__gc *gc, uint32_t domid, libxl_device_pci *pcidev, int starting)
{
    libxl_ctx *ctx = libxl__gc_owner(gc);
    flexarray_t *back;
    char *num_devs, *be_path;
    int num = 0;
    xs_transaction_t t;

    be_path = libxl__sprintf(gc, "%s/backend/pci/%d/0", libxl__xs_get_dompath(gc, 0), domid);
    num_devs = libxl__xs_read(gc, XBT_NULL, libxl__sprintf(gc, "%s/num_devs", be_path));
    if (!num_devs)
        return libxl__create_pci_backend(gc, domid, pcidev, 1);

    libxl_domain_type domtype = libxl__domain_type(gc, domid);
    if (domtype == LIBXL_DOMAIN_TYPE_INVALID)
        return ERROR_FAIL;

    if (!starting && domtype == LIBXL_DOMAIN_TYPE_PV) {
        if (libxl__wait_for_backend(gc, be_path, "4") < 0)
            return ERROR_FAIL;
    }

    back = flexarray_make(gc, 16, 1);

    LIBXL__LOG(ctx, LIBXL__LOG_DEBUG, "Adding new pci device to xenstore");
    num = atoi(num_devs);
    libxl_create_pci_backend_device(gc, back, num, pcidev);
    flexarray_append_pair(back, "num_devs", libxl__sprintf(gc, "%d", num + 1));
    if (!starting)
        flexarray_append_pair(back, "state", libxl__sprintf(gc, "%d", 7));

retry_transaction:
    t = xs_transaction_start(ctx->xsh);
    libxl__xs_writev(gc, t, be_path,
                    libxl__xs_kvs_of_flexarray(gc, back, back->count));
    if (!xs_transaction_end(ctx->xsh, t, 0))
        if (errno == EAGAIN)
            goto retry_transaction;

    return 0;
}

static int libxl__device_pci_remove_xenstore(libxl__gc *gc, uint32_t domid, libxl_device_pci *pcidev)
{
    libxl_ctx *ctx = libxl__gc_owner(gc);
    char *be_path, *num_devs_path, *num_devs, *xsdev, *tmp, *tmppath;
    int num, i, j;
    xs_transaction_t t;

    be_path = libxl__sprintf(gc, "%s/backend/pci/%d/0", libxl__xs_get_dompath(gc, 0), domid);
    num_devs_path = libxl__sprintf(gc, "%s/num_devs", be_path);
    num_devs = libxl__xs_read(gc, XBT_NULL, num_devs_path);
    if (!num_devs)
        return ERROR_INVAL;
    num = atoi(num_devs);

    libxl_domain_type domtype = libxl__domain_type(gc, domid);
    if (domtype == LIBXL_DOMAIN_TYPE_INVALID)
        return ERROR_FAIL;

    if (domtype == LIBXL_DOMAIN_TYPE_PV) {
        if (libxl__wait_for_backend(gc, be_path, "4") < 0) {
            LIBXL__LOG(ctx, LIBXL__LOG_DEBUG, "pci backend at %s is not ready", be_path);
            return ERROR_FAIL;
        }
    }

    for (i = 0; i < num; i++) {
        unsigned int domain = 0, bus = 0, dev = 0, func = 0;
        xsdev = libxl__xs_read(gc, XBT_NULL, libxl__sprintf(gc, "%s/dev-%d", be_path, i));
        sscanf(xsdev, PCI_BDF, &domain, &bus, &dev, &func);
        if (domain == pcidev->domain && bus == pcidev->bus &&
            pcidev->dev == dev && pcidev->func == func) {
            break;
        }
    }
    if (i == num) {
        LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "Couldn't find the device on xenstore");
        return ERROR_INVAL;
    }

retry_transaction:
    t = xs_transaction_start(ctx->xsh);
    xs_write(ctx->xsh, t, libxl__sprintf(gc, "%s/state-%d", be_path, i), "5", strlen("5"));
    xs_write(ctx->xsh, t, libxl__sprintf(gc, "%s/state", be_path), "7", strlen("7"));
    if (!xs_transaction_end(ctx->xsh, t, 0))
        if (errno == EAGAIN)
            goto retry_transaction;

    if (domtype == LIBXL_DOMAIN_TYPE_PV) {
        if (libxl__wait_for_backend(gc, be_path, "4") < 0) {
            LIBXL__LOG(ctx, LIBXL__LOG_DEBUG, "pci backend at %s is not ready", be_path);
            return ERROR_FAIL;
        }
    }

retry_transaction2:
    t = xs_transaction_start(ctx->xsh);
    xs_rm(ctx->xsh, t, libxl__sprintf(gc, "%s/state-%d", be_path, i));
    xs_rm(ctx->xsh, t, libxl__sprintf(gc, "%s/key-%d", be_path, i));
    xs_rm(ctx->xsh, t, libxl__sprintf(gc, "%s/dev-%d", be_path, i));
    xs_rm(ctx->xsh, t, libxl__sprintf(gc, "%s/vdev-%d", be_path, i));
    xs_rm(ctx->xsh, t, libxl__sprintf(gc, "%s/opts-%d", be_path, i));
    xs_rm(ctx->xsh, t, libxl__sprintf(gc, "%s/vdevfn-%d", be_path, i));
    libxl__xs_write(gc, t, num_devs_path, "%d", num - 1);
    for (j = i + 1; j < num; j++) {
        tmppath = libxl__sprintf(gc, "%s/state-%d", be_path, j);
        tmp = libxl__xs_read(gc, t, tmppath);
        xs_write(ctx->xsh, t, libxl__sprintf(gc, "%s/state-%d", be_path, j - 1), tmp, strlen(tmp));
        xs_rm(ctx->xsh, t, tmppath);
        tmppath = libxl__sprintf(gc, "%s/dev-%d", be_path, j);
        tmp = libxl__xs_read(gc, t, tmppath);
        xs_write(ctx->xsh, t, libxl__sprintf(gc, "%s/dev-%d", be_path, j - 1), tmp, strlen(tmp));
        xs_rm(ctx->xsh, t, tmppath);
        tmppath = libxl__sprintf(gc, "%s/key-%d", be_path, j);
        tmp = libxl__xs_read(gc, t, tmppath);
        xs_write(ctx->xsh, t, libxl__sprintf(gc, "%s/key-%d", be_path, j - 1), tmp, strlen(tmp));
        xs_rm(ctx->xsh, t, tmppath);
        tmppath = libxl__sprintf(gc, "%s/vdev-%d", be_path, j);
        tmp = libxl__xs_read(gc, t, tmppath);
        if (tmp) {
            xs_write(ctx->xsh, t, libxl__sprintf(gc, "%s/vdev-%d", be_path, j - 1), tmp, strlen(tmp));
            xs_rm(ctx->xsh, t, tmppath);
        }
        tmppath = libxl__sprintf(gc, "%s/opts-%d", be_path, j);
        tmp = libxl__xs_read(gc, t, tmppath);
        if (tmp) {
            xs_write(ctx->xsh, t, libxl__sprintf(gc, "%s/opts-%d", be_path, j - 1), tmp, strlen(tmp));
            xs_rm(ctx->xsh, t, tmppath);
        }
        tmppath = libxl__sprintf(gc, "%s/vdevfn-%d", be_path, j);
        tmp = libxl__xs_read(gc, t, tmppath);
        if (tmp) {
            xs_write(ctx->xsh, t, libxl__sprintf(gc, "%s/vdevfn-%d", be_path, j - 1), tmp, strlen(tmp));
            xs_rm(ctx->xsh, t, tmppath);
        }
    }
    if (!xs_transaction_end(ctx->xsh, t, 0))
        if (errno == EAGAIN)
            goto retry_transaction2;

    if (num == 1) {
        libxl__device dev;
        if (libxl__parse_backend_path(gc, be_path, &dev) != 0)
            return ERROR_FAIL;

        dev.domid = domid;
        dev.kind = LIBXL__DEVICE_KIND_PCI;
        dev.devid = 0;

        libxl__device_destroy(gc, &dev);
        return 0;
    }

    return 0;
}

static int get_all_assigned_devices(libxl__gc *gc, libxl_device_pci **list, int *num)
{
    char **domlist;
    unsigned int nd = 0, i;

    *list = NULL;
    *num = 0;

    domlist = libxl__xs_directory(gc, XBT_NULL, "/local/domain", &nd);
    for(i = 0; i < nd; i++) {
        char *path, *num_devs;

        path = libxl__sprintf(gc, "/local/domain/0/backend/pci/%s/0/num_devs", domlist[i]);
        num_devs = libxl__xs_read(gc, XBT_NULL, path);
        if ( num_devs ) {
            int ndev = atoi(num_devs), j;
            char *devpath, *bdf;

            for(j = 0; j < ndev; j++) {
                devpath = libxl__sprintf(gc, "/local/domain/0/backend/pci/%s/0/dev-%u",
                                        domlist[i], j);
                bdf = libxl__xs_read(gc, XBT_NULL, devpath);
                if ( bdf ) {
                    unsigned dom, bus, dev, func;
                    if ( sscanf(bdf, PCI_BDF, &dom, &bus, &dev, &func) != 4 )
                        continue;

                    *list = realloc(*list, sizeof(libxl_device_pci) * ((*num) + 1));
                    if (*list == NULL)
                        return ERROR_NOMEM;
                    pcidev_struct_fill(*list + *num, dom, bus, dev, func, 0);
                    (*num)++;
                }
            }
        }
    }
    libxl__ptr_add(gc, *list);

    return 0;
}

static int is_pcidev_in_array(libxl_device_pci *assigned, int num_assigned,
                       int dom, int bus, int dev, int func)
{
    int i;

    for(i = 0; i < num_assigned; i++) {
        if ( assigned[i].domain != dom )
            continue;
        if ( assigned[i].bus != bus )
            continue;
        if ( assigned[i].dev != dev )
            continue;
        if ( assigned[i].func != func )
            continue;
        return 1;
    }

    return 0;
}

/* Write the standard BDF into the sysfs path given by sysfs_path. */
static int sysfs_write_bdf(libxl__gc *gc, const char * sysfs_path,
                           libxl_device_pci *pcidev)
{
    libxl_ctx *ctx = libxl__gc_owner(gc);
    int rc, fd;
    char *buf;

    fd = open(sysfs_path, O_WRONLY);
    if (fd < 0) {
        LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "Couldn't open %s",
                         sysfs_path);
        return ERROR_FAIL;
    }

    buf = libxl__sprintf(gc, PCI_BDF, pcidev->domain, pcidev->bus,
                         pcidev->dev, pcidev->func);
    rc = write(fd, buf, strlen(buf));
    /* Annoying to have two if's, but we need the errno */
    if (rc < 0)
        LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR,
                         "write to %s returned %d", sysfs_path, rc);
    close(fd);

    if (rc < 0)
        return ERROR_FAIL;

    return 0;
}

libxl_device_pci *libxl_device_pci_assignable_list(libxl_ctx *ctx, int *num)
{
    GC_INIT(ctx);
    libxl_device_pci *pcidevs = NULL, *new, *assigned;
    struct dirent *de;
    DIR *dir;
    int rc, num_assigned;

    *num = 0;

    rc = get_all_assigned_devices(gc, &assigned, &num_assigned);
    if ( rc )
        goto out;

    dir = opendir(SYSFS_PCIBACK_DRIVER);
    if ( NULL == dir ) {
        if ( errno == ENOENT ) {
            LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "Looks like pciback driver not loaded");
        }else{
            LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "Couldn't open %s", SYSFS_PCIBACK_DRIVER);
        }
        goto out_closedir;
    }

    while( (de = readdir(dir)) ) {
        unsigned dom, bus, dev, func;
        if ( sscanf(de->d_name, PCI_BDF, &dom, &bus, &dev, &func) != 4 )
            continue;

        if ( is_pcidev_in_array(assigned, num_assigned, dom, bus, dev, func) )
            continue;

        new = realloc(pcidevs, ((*num) + 1) * sizeof(*new));
        if ( NULL == new )
            continue;

        pcidevs = new;
        new = pcidevs + *num;

        memset(new, 0, sizeof(*new));
        pcidev_struct_fill(new, dom, bus, dev, func, 0);
        (*num)++;
    }

out_closedir:
    closedir(dir);
out:
    GC_FREE;
    return pcidevs;
}

/* Unbind device from its current driver, if any.  If driver_path is non-NULL,
 * store the path to the original driver in it. */
static int sysfs_dev_unbind(libxl__gc *gc, libxl_device_pci *pcidev,
                            char **driver_path)
{
    libxl_ctx *ctx = libxl__gc_owner(gc);
    char * spath, *dp = NULL;
    struct stat st;

    spath = libxl__sprintf(gc, SYSFS_PCI_DEV"/"PCI_BDF"/driver",
                           pcidev->domain,
                           pcidev->bus,
                           pcidev->dev,
                           pcidev->func);
    if ( !lstat(spath, &st) ) {
        /* Find the canonical path to the driver. */
        dp = libxl__zalloc(gc, PATH_MAX);
        dp = realpath(spath, dp);
        if ( !dp ) {
            LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "realpath() failed");
            return -1;
        }

        LIBXL__LOG(ctx, LIBXL__LOG_DEBUG, "Driver re-plug path: %s",
                   dp);

        /* Unbind from the old driver */
        spath = libxl__sprintf(gc, "%s/unbind", dp);
        if ( sysfs_write_bdf(gc, spath, pcidev) < 0 ) {
            LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "Couldn't unbind device");
            return -1;
        }
    }

    if ( driver_path )
        *driver_path = dp;

    return 0;
}

/*
 * A brief comment about slots.  I don't know what slots are for; however,
 * I have by experimentation determined:
 * - Before a device can be bound to pciback, its BDF must first be listed
 *   in pciback/slots
 * - The way to get the BDF listed there is to write BDF to
 *   pciback/new_slot
 * - Writing the same BDF to pciback/new_slot is not idempotent; it results
 *   in two entries of the BDF in pciback/slots
 * It's not clear whether having two entries in pciback/slots is a problem
 * or not.  Just to be safe, this code does the conservative thing, and
 * first checks to see if there is a slot, adding one only if one does not
 * already exist.
 */

/* Scan through /sys/.../pciback/slots looking for pcidev's BDF */
static int pciback_dev_has_slot(libxl__gc *gc, libxl_device_pci *pcidev)
{
    libxl_ctx *ctx = libxl__gc_owner(gc);
    FILE *f;
    int rc = 0;
    unsigned dom, bus, dev, func;

    f = fopen(SYSFS_PCIBACK_DRIVER"/slots", "r");

    if (f == NULL) {
        LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "Couldn't open %s",
                         SYSFS_PCIBACK_DRIVER"/slots");
        return ERROR_FAIL;
    }

    while(fscanf(f, "%x:%x:%x.%d\n", &dom, &bus, &dev, &func)==4) {
        if(dom == pcidev->domain
           && bus == pcidev->bus
           && dev == pcidev->dev
           && func == pcidev->func) {
            rc = 1;
            goto out;
        }
    }
out:
    fclose(f);
    return rc;
}

static int pciback_dev_is_assigned(libxl__gc *gc, libxl_device_pci *pcidev)
{
    libxl_ctx *ctx = libxl__gc_owner(gc);
    char * spath;
    int rc;
    struct stat st;

    spath = libxl__sprintf(gc, SYSFS_PCIBACK_DRIVER"/"PCI_BDF,
                           pcidev->domain, pcidev->bus,
                           pcidev->dev, pcidev->func);
    rc = lstat(spath, &st);

    if( rc == 0 )
        return 1;
    if ( rc < 0 && errno == ENOENT )
        return 0;
    LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "Accessing %s", spath);
    return -1;
}

static int pciback_dev_assign(libxl__gc *gc, libxl_device_pci *pcidev)
{
    libxl_ctx *ctx = libxl__gc_owner(gc);
    int rc;

    if ( (rc=pciback_dev_has_slot(gc, pcidev)) < 0 ) {
        LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR,
                         "Error checking for pciback slot");
        return ERROR_FAIL;
    } else if (rc == 0) {
        if ( sysfs_write_bdf(gc, SYSFS_PCIBACK_DRIVER"/new_slot",
                             pcidev) < 0 ) {
            LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR,
                       "Couldn't bind device to pciback!");
            return ERROR_FAIL;
        }
    }

    if ( sysfs_write_bdf(gc, SYSFS_PCIBACK_DRIVER"/bind", pcidev) < 0 ) {
        LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR,
                         "Couldn't bind device to pciback!");
        return ERROR_FAIL;
    }
    return 0;
}

static int pciback_dev_unassign(libxl__gc *gc, libxl_device_pci *pcidev)
{
    libxl_ctx *ctx = libxl__gc_owner(gc);

    /* Remove from pciback */
    if ( sysfs_dev_unbind(gc, pcidev, NULL) < 0 ) {
        LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "Couldn't unbind device!");
        return ERROR_FAIL;
    }

    /* Remove slot if necessary */
    if ( pciback_dev_has_slot(gc, pcidev) > 0 ) {
        if ( sysfs_write_bdf(gc, SYSFS_PCIBACK_DRIVER"/remove_slot",
                             pcidev) < 0 ) {
            LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR,
                             "Couldn't remove pciback slot");
            return ERROR_FAIL;
        }
    }
    return 0;
}

#define PCIBACK_INFO_PATH "/libxl/pciback"

static void pci_assignable_driver_path_write(libxl__gc *gc,
                                            libxl_device_pci *pcidev,
                                            char *driver_path)
{
    libxl_ctx *ctx = libxl__gc_owner(gc);
    char *path;

    path = libxl__sprintf(gc, PCIBACK_INFO_PATH"/"PCI_BDF_XSPATH"/driver_path",
                          pcidev->domain,
                          pcidev->bus,
                          pcidev->dev,
                          pcidev->func);
    if ( libxl__xs_write(gc, XBT_NULL, path, "%s", driver_path) < 0 ) {
        LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_WARNING,
                         "Write of %s to node %s failed.",
                         driver_path, path);
    }
}

static char * pci_assignable_driver_path_read(libxl__gc *gc,
                                              libxl_device_pci *pcidev)
{
    return libxl__xs_read(gc, XBT_NULL,
                          libxl__sprintf(gc,
                           PCIBACK_INFO_PATH "/" PCI_BDF_XSPATH "/driver_path",
                           pcidev->domain,
                           pcidev->bus,
                           pcidev->dev,
                           pcidev->func));
}

static void pci_assignable_driver_path_remove(libxl__gc *gc,
                                              libxl_device_pci *pcidev)
{
    libxl_ctx *ctx = libxl__gc_owner(gc);

    /* Remove the xenstore entry */
    xs_rm(ctx->xsh, XBT_NULL,
          libxl__sprintf(gc, PCIBACK_INFO_PATH "/" PCI_BDF_XSPATH,
                         pcidev->domain,
                         pcidev->bus,
                         pcidev->dev,
                         pcidev->func) );
}

static int libxl__device_pci_assignable_add(libxl__gc *gc,
                                            libxl_device_pci *pcidev,
                                            int rebind)
{
    libxl_ctx *ctx = libxl__gc_owner(gc);
    unsigned dom, bus, dev, func;
    char *spath, *driver_path = NULL;
    struct stat st;

    /* Local copy for convenience */
    dom = pcidev->domain;
    bus = pcidev->bus;
    dev = pcidev->dev;
    func = pcidev->func;

    /* See if the device exists */
    spath = libxl__sprintf(gc, SYSFS_PCI_DEV"/"PCI_BDF, dom, bus, dev, func);
    if ( lstat(spath, &st) ) {
        LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "Couldn't lstat %s", spath);
        return ERROR_FAIL;
    }

    /* Check to see if it's already assigned to pciback */
    if ( pciback_dev_is_assigned(gc, pcidev) ) {
        LIBXL__LOG(ctx, LIBXL__LOG_WARNING, PCI_BDF" already assigned to pciback",
                   dom, bus, dev, func);
        return 0;
    }

    /* Check to see if there's already a driver that we need to unbind from */
    if ( sysfs_dev_unbind(gc, pcidev, &driver_path ) ) {
        LIBXL__LOG(ctx, LIBXL__LOG_ERROR,
                   "Couldn't unbind "PCI_BDF" from driver",
                   dom, bus, dev, func);
        return ERROR_FAIL;
    }

    /* Store driver_path for rebinding to dom0 */
    if ( rebind ) {
        if ( driver_path ) {
            pci_assignable_driver_path_write(gc, pcidev, driver_path);
        } else {
            LIBXL__LOG(ctx, LIBXL__LOG_WARNING,
                       PCI_BDF" not bound to a driver, will not be rebound.",
                       dom, bus, dev, func);
        }
    }

    if ( pciback_dev_assign(gc, pcidev) ) {
        LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "Couldn't bind device to pciback!");
        return ERROR_FAIL;
    }

    return 0;
}

static int libxl__device_pci_assignable_remove(libxl__gc *gc,
                                               libxl_device_pci *pcidev,
                                               int rebind)
{
    libxl_ctx *ctx = libxl__gc_owner(gc);
    int rc;
    char *driver_path;

    /* Unbind from pciback */
    if ( (rc=pciback_dev_is_assigned(gc, pcidev)) < 0 ) {
        LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "Checking if pciback was assigned");
        return ERROR_FAIL;
    } else if ( rc ) {
        pciback_dev_unassign(gc, pcidev);
    } else {
        LIBXL__LOG(ctx, LIBXL__LOG_WARNING,
                   "Not bound to pciback");
    }

    /* Rebind if necessary */
    driver_path = pci_assignable_driver_path_read(gc, pcidev);

    if ( driver_path ) {
        if ( rebind ) {
            LIBXL__LOG(ctx, LIBXL__LOG_INFO, "Rebinding to driver at %s",
                       driver_path);

            if ( sysfs_write_bdf(gc,
                                 libxl__sprintf(gc, "%s/bind", driver_path),
                                 pcidev) < 0 ) {
                LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR,
                                 "Couldn't bind device to %s", driver_path);
                return -1;
            }
        }

        pci_assignable_driver_path_remove(gc, pcidev);
    } else {
        if ( rebind ) {
            LIBXL__LOG(ctx, LIBXL__LOG_WARNING,
                       "Couldn't find path for original driver; not rebinding");
        }
    }

    return 0;
}

int libxl_device_pci_assignable_add(libxl_ctx *ctx, libxl_device_pci *pcidev,
                                    int rebind)
{
    GC_INIT(ctx);
    int rc;

    rc = libxl__device_pci_assignable_add(gc, pcidev, rebind);

    GC_FREE;
    return rc;
}


int libxl_device_pci_assignable_remove(libxl_ctx *ctx, libxl_device_pci *pcidev,
                                       int rebind)
{
    GC_INIT(ctx);
    int rc;

    rc = libxl__device_pci_assignable_remove(gc, pcidev, rebind);

    GC_FREE;
    return rc;
}

/*
 * This function checks that all functions of a device are bound to pciback
 * driver. It also initialises a bit-mask of which function numbers are present
 * on that device.
*/
static int pci_multifunction_check(libxl__gc *gc, libxl_device_pci *pcidev, unsigned int *func_mask)
{
    libxl_ctx *ctx = libxl__gc_owner(gc);
    struct dirent *de;
    DIR *dir;

    *func_mask = 0;

    dir = opendir(SYSFS_PCI_DEV);
    if ( NULL == dir ) {
        LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "Couldn't open %s", SYSFS_PCI_DEV);
        return -1;
    }

    while( (de = readdir(dir)) ) {
        unsigned dom, bus, dev, func;
        struct stat st;
        char *path;

        if ( sscanf(de->d_name, PCI_BDF, &dom, &bus, &dev, &func) != 4 )
            continue;
        if ( pcidev->domain != dom )
            continue;
        if ( pcidev->bus != bus )
            continue;
        if ( pcidev->dev != dev )
            continue;

        path = libxl__sprintf(gc, "%s/" PCI_BDF, SYSFS_PCIBACK_DRIVER, dom, bus, dev, func);
        if ( lstat(path, &st) ) {
            if ( errno == ENOENT )
                LIBXL__LOG(ctx, LIBXL__LOG_ERROR, PCI_BDF " is not assigned to pciback driver",
                       dom, bus, dev, func);
            else
                LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "Couldn't lstat %s", path);
            closedir(dir);
            return -1;
        }
        (*func_mask) |= (1 << func);
    }

    closedir(dir);
    return 0;
}

static int pci_ins_check(libxl__gc *gc, uint32_t domid, const char *state, void *priv)
{
    char *orig_state = priv;

    if ( !strcmp(state, "pci-insert-failed") )
        return -1;
    if ( !strcmp(state, "pci-inserted") )
        return 0;
    if ( !strcmp(state, orig_state) )
        return 1;

    return 1;
}

static int qemu_pci_add_xenstore(libxl__gc *gc, uint32_t domid,
                                 libxl_device_pci *pcidev)
{
    libxl_ctx *ctx = libxl__gc_owner(gc);
    int rc = 0;
    char *path;
    char *state, *vdevfn;

    path = libxl__sprintf(gc, "/local/domain/0/device-model/%d/state", domid);
    state = libxl__xs_read(gc, XBT_NULL, path);
    path = libxl__sprintf(gc, "/local/domain/0/device-model/%d/parameter",
                          domid);
    if (pcidev->vdevfn) {
        libxl__xs_write(gc, XBT_NULL, path, PCI_BDF_VDEVFN","PCI_OPTIONS,
                        pcidev->domain, pcidev->bus, pcidev->dev,
                        pcidev->func, pcidev->vdevfn, pcidev->msitranslate,
                        pcidev->power_mgmt);
    } else {
        libxl__xs_write(gc, XBT_NULL, path, PCI_BDF","PCI_OPTIONS,
                        pcidev->domain,  pcidev->bus, pcidev->dev,
                        pcidev->func, pcidev->msitranslate, pcidev->power_mgmt);
    }

    libxl__qemu_traditional_cmd(gc, domid, "pci-ins");
    rc = libxl__wait_for_device_model_deprecated(gc, domid, NULL, NULL,
                                      pci_ins_check, state);
    path = libxl__sprintf(gc, "/local/domain/0/device-model/%d/parameter",
                          domid);
    vdevfn = libxl__xs_read(gc, XBT_NULL, path);
    path = libxl__sprintf(gc, "/local/domain/0/device-model/%d/state",
                          domid);
    if ( rc < 0 )
        LIBXL__LOG(ctx, LIBXL__LOG_ERROR,
                   "qemu refused to add device: %s", vdevfn);
    else if ( sscanf(vdevfn, "0x%x", &pcidev->vdevfn) != 1 ) {
        LIBXL__LOG(ctx, LIBXL__LOG_ERROR,
                   "wrong format for the vdevfn: '%s'", vdevfn);
        rc = -1;
    }
    xs_write(ctx->xsh, XBT_NULL, path, state, strlen(state));

    return rc;
}

static int do_pci_add(libxl__gc *gc, uint32_t domid, libxl_device_pci *pcidev, int starting)
{
    libxl_ctx *ctx = libxl__gc_owner(gc);
    int rc, hvm = 0;

    switch (libxl__domain_type(gc, domid)) {
    case LIBXL_DOMAIN_TYPE_HVM:
        hvm = 1;
        if (libxl__wait_for_device_model_deprecated(gc, domid, "running",
                                         NULL, NULL, NULL) < 0) {
            return ERROR_FAIL;
        }
        switch (libxl__device_model_version_running(gc, domid)) {
            case LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN_TRADITIONAL:
                rc = qemu_pci_add_xenstore(gc, domid, pcidev);
                break;
            case LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN:
                rc = libxl__qmp_pci_add(gc, domid, pcidev);
                break;
            default:
                return ERROR_INVAL;
        }
        if ( rc )
            return ERROR_FAIL;
        break;
    case LIBXL_DOMAIN_TYPE_PV:
    {
        char *sysfs_path = libxl__sprintf(gc, SYSFS_PCI_DEV"/"PCI_BDF"/resource", pcidev->domain,
                                         pcidev->bus, pcidev->dev, pcidev->func);
        FILE *f = fopen(sysfs_path, "r");
        unsigned long long start = 0, end = 0, flags = 0, size = 0;
        int irq = 0;
        int i;

        if (f == NULL) {
            LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "Couldn't open %s", sysfs_path);
            return ERROR_FAIL;
        }
        for (i = 0; i < PROC_PCI_NUM_RESOURCES; i++) {
            if (fscanf(f, "0x%llx 0x%llx 0x%llx\n", &start, &end, &flags) != 3)
                continue;
            size = end - start + 1;
            if (start) {
                if (flags & PCI_BAR_IO) {
                    rc = xc_domain_ioport_permission(ctx->xch, domid, start, size, 1);
                    if (rc < 0) {
                        LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "Error: xc_domain_ioport_permission error 0x%llx/0x%llx", start, size);
                        fclose(f);
                        return ERROR_FAIL;
                    }
                } else {
                    rc = xc_domain_iomem_permission(ctx->xch, domid, start>>XC_PAGE_SHIFT,
                                                    (size+(XC_PAGE_SIZE-1))>>XC_PAGE_SHIFT, 1);
                    if (rc < 0) {
                        LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "Error: xc_domain_iomem_permission error 0x%llx/0x%llx", start, size);
                        fclose(f);
                        return ERROR_FAIL;
                    }
                }
            }
        }
        fclose(f);
        sysfs_path = libxl__sprintf(gc, SYSFS_PCI_DEV"/"PCI_BDF"/irq", pcidev->domain,
                                   pcidev->bus, pcidev->dev, pcidev->func);
        f = fopen(sysfs_path, "r");
        if (f == NULL) {
            LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "Couldn't open %s", sysfs_path);
            goto out;
        }
        if ((fscanf(f, "%u", &irq) == 1) && irq) {
            rc = xc_physdev_map_pirq(ctx->xch, domid, irq, &irq);
            if (rc < 0) {
                LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "Error: xc_physdev_map_pirq irq=%d", irq);
                fclose(f);
                return ERROR_FAIL;
            }
            rc = xc_domain_irq_permission(ctx->xch, domid, irq, 1);
            if (rc < 0) {
                LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "Error: xc_domain_irq_permission irq=%d", irq);
                fclose(f);
                return ERROR_FAIL;
            }
        }
        fclose(f);

        /* Don't restrict writes to the PCI config space from this VM */
        if (pcidev->permissive) {
            if ( sysfs_write_bdf(gc, SYSFS_PCIBACK_DRIVER"/permissive",
                                 pcidev) < 0 ) {
                LIBXL__LOG(ctx, LIBXL__LOG_ERROR,
                           "Setting permissive for device");
                return ERROR_FAIL;
            }
        }
        break;
    }
    case LIBXL_DOMAIN_TYPE_INVALID:
        return ERROR_FAIL;
    }
out:
    if (!libxl_is_stubdom(ctx, domid, NULL)) {
        rc = xc_assign_device(ctx->xch, domid, pcidev_encode_bdf(pcidev));
        if (rc < 0 && (hvm || errno != ENOSYS)) {
            LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "xc_assign_device failed");
            return ERROR_FAIL;
        }
    }

    if (!starting)
        rc = libxl__device_pci_add_xenstore(gc, domid, pcidev, starting);
    else
        rc = 0;
    return rc;
}

static int libxl__device_pci_reset(libxl__gc *gc, unsigned int domain, unsigned int bus,
                                   unsigned int dev, unsigned int func)
{
    libxl_ctx *ctx = libxl__gc_owner(gc);
    char *reset;
    int fd, rc;

    reset = libxl__sprintf(gc, "%s/pciback/do_flr", SYSFS_PCI_DEV);
    fd = open(reset, O_WRONLY);
    if (fd >= 0) {
        char *buf = libxl__sprintf(gc, PCI_BDF, domain, bus, dev, func);
        rc = write(fd, buf, strlen(buf));
        if (rc < 0)
            LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "write to %s returned %d", reset, rc);
        close(fd);
        return rc < 0 ? rc : 0;
    }
    if (errno != ENOENT)
        LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "Failed to access pciback path %s", reset);
    reset = libxl__sprintf(gc, "%s/"PCI_BDF"/reset", SYSFS_PCI_DEV, domain, bus, dev, func);
    fd = open(reset, O_WRONLY);
    if (fd >= 0) {
        rc = write(fd, "1", 1);
        if (rc < 0)
            LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "write to %s returned %d", reset, rc);
        close(fd);
        return rc < 0 ? rc : 0;
    }
    if (errno == ENOENT) {
        LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "The kernel doesn't support reset from sysfs for PCI device "PCI_BDF, domain, bus, dev, func);
    } else {
        LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "Failed to access reset path %s", reset);
    }
    return -1;
}

int libxl__device_pci_setdefault(libxl__gc *gc, libxl_device_pci *pci)
{
    return 0;
}

int libxl_device_pci_add(libxl_ctx *ctx, uint32_t domid,
                         libxl_device_pci *pcidev,
                         const libxl_asyncop_how *ao_how)
{
    AO_CREATE(ctx, domid, ao_how);
    int rc;
    rc = libxl__device_pci_add(gc, domid, pcidev, 0);
    libxl__ao_complete(egc, ao, rc);
    return AO_INPROGRESS;
}

static int libxl_pcidev_assignable(libxl_ctx *ctx, libxl_device_pci *pcidev)
{
    libxl_device_pci *pcidevs;
    int num, i;

    pcidevs = libxl_device_pci_assignable_list(ctx, &num);
    for (i = 0; i < num; i++) {
        if (pcidevs[i].domain == pcidev->domain &&
            pcidevs[i].bus == pcidev->bus &&
            pcidevs[i].dev == pcidev->dev &&
            pcidevs[i].func == pcidev->func)
            break;
    }
    free(pcidevs);
    return i != num;
}

int libxl__device_pci_add(libxl__gc *gc, uint32_t domid, libxl_device_pci *pcidev, int starting)
{
    libxl_ctx *ctx = libxl__gc_owner(gc);
    unsigned int orig_vdev, pfunc_mask;
    libxl_device_pci *assigned;
    int num_assigned, i, rc;
    int stubdomid = 0;

    if (libxl__domain_type(gc, domid) == LIBXL_DOMAIN_TYPE_HVM) {
        rc = xc_test_assign_device(ctx->xch, domid, pcidev_encode_bdf(pcidev));
        if (rc) {
            LIBXL__LOG(ctx, LIBXL__LOG_ERROR,
                       "PCI device %04x:%02x:%02x.%u %s?",
                       pcidev->domain, pcidev->bus, pcidev->dev, pcidev->func,
                       errno == ENOSYS ? "cannot be assigned - no IOMMU"
                                       : "already assigned to a different guest");
            goto out;
        }
    }

    rc = libxl__device_pci_setdefault(gc, pcidev);
    if (rc) goto out;

    if (!libxl_pcidev_assignable(ctx, pcidev)) {
        LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "PCI device %x:%x:%x.%x is not assignable",
                   pcidev->domain, pcidev->bus, pcidev->dev, pcidev->func);
        rc = ERROR_FAIL;
        goto out;
    }

    rc = get_all_assigned_devices(gc, &assigned, &num_assigned);
    if ( rc ) {
        LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "cannot determine if device is assigned, refusing to continue");
        goto out;
    }
    if ( is_pcidev_in_array(assigned, num_assigned, pcidev->domain,
                     pcidev->bus, pcidev->dev, pcidev->func) ) {
        LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "PCI device already attached to a domain");
        rc = ERROR_FAIL;
        goto out;
    }

    libxl__device_pci_reset(gc, pcidev->domain, pcidev->bus, pcidev->dev, pcidev->func);

    stubdomid = libxl_get_stubdom_id(ctx, domid);
    if (stubdomid != 0) {
        libxl_device_pci pcidev_s = *pcidev;
        /* stubdomain is always running by now, even at create time */
        rc = do_pci_add(gc, stubdomid, &pcidev_s, 0);
        if ( rc )
            goto out;
    }

    orig_vdev = pcidev->vdevfn & ~7U;

    if ( pcidev->vfunc_mask == LIBXL_PCI_FUNC_ALL ) {
        if ( !(pcidev->vdevfn >> 3) ) {
            LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "Must specify a v-slot for multi-function devices");
            rc = ERROR_INVAL;
            goto out;
        }
        if ( pci_multifunction_check(gc, pcidev, &pfunc_mask) ) {
            rc = ERROR_FAIL;
            goto out;
        }
        pcidev->vfunc_mask &= pfunc_mask;
        /* so now vfunc_mask == pfunc_mask */
    }else{
        pfunc_mask = (1 << pcidev->func);
    }

    for(rc = 0, i = 7; i >= 0; --i) {
        if ( (1 << i) & pfunc_mask ) {
            if ( pcidev->vfunc_mask == pfunc_mask ) {
                pcidev->func = i;
                pcidev->vdevfn = orig_vdev | i;
            }else{
                /* if not passing through multiple devices in a block make
                 * sure that virtual function number 0 is always used otherwise
                 * guest won't see the device
                 */
                pcidev->vdevfn = orig_vdev;
            }
            if ( do_pci_add(gc, domid, pcidev, starting) )
                rc = ERROR_FAIL;
        }
    }

out:
    return rc;
}

static int qemu_pci_remove_xenstore(libxl__gc *gc, uint32_t domid,
                                    libxl_device_pci *pcidev, int force)
{
    libxl_ctx *ctx = libxl__gc_owner(gc);
    char *state;
    char *path;

    path = libxl__sprintf(gc, "/local/domain/0/device-model/%d/state", domid);
    state = libxl__xs_read(gc, XBT_NULL, path);
    path = libxl__sprintf(gc, "/local/domain/0/device-model/%d/parameter", domid);
    libxl__xs_write(gc, XBT_NULL, path, PCI_BDF, pcidev->domain,
                    pcidev->bus, pcidev->dev, pcidev->func);

    /* Remove all functions at once atomically by only signalling
     * device-model for function 0 */
    if ( !force && (pcidev->vdevfn & 0x7) == 0 ) {
        libxl__qemu_traditional_cmd(gc, domid, "pci-rem");
        if (libxl__wait_for_device_model_deprecated(gc, domid, "pci-removed",
                                         NULL, NULL, NULL) < 0) {
            LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "Device Model didn't respond in time");
            /* This depends on guest operating system acknowledging the
             * SCI, if it doesn't respond in time then we may wish to
             * force the removal.
             */
            return ERROR_FAIL;
        }
    }
    path = libxl__sprintf(gc, "/local/domain/0/device-model/%d/state", domid);
    xs_write(ctx->xsh, XBT_NULL, path, state, strlen(state));

    return 0;
}

static int libxl__device_pci_remove_common(libxl__gc *gc, uint32_t domid,
                                           libxl_device_pci *pcidev, int force);

static int do_pci_remove(libxl__gc *gc, uint32_t domid,
                         libxl_device_pci *pcidev, int force)
{
    libxl_ctx *ctx = libxl__gc_owner(gc);
    libxl_device_pci *assigned;
    int hvm = 0, rc, num;
    int stubdomid = 0;

    assigned = libxl_device_pci_list(ctx, domid, &num);
    if ( assigned == NULL )
        return ERROR_FAIL;

    rc = ERROR_INVAL;
    if ( !is_pcidev_in_array(assigned, num, pcidev->domain,
                      pcidev->bus, pcidev->dev, pcidev->func) ) {
        LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "PCI device not attached to this domain");
        goto out_fail;
    }

    rc = ERROR_FAIL;
    switch (libxl__domain_type(gc, domid)) {
    case LIBXL_DOMAIN_TYPE_HVM:
        hvm = 1;
        if (libxl__wait_for_device_model_deprecated(gc, domid, "running",
                                         NULL, NULL, NULL) < 0)
            goto out_fail;

        switch (libxl__device_model_version_running(gc, domid)) {
        case LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN_TRADITIONAL:
            rc = qemu_pci_remove_xenstore(gc, domid, pcidev, force);
            break;
        case LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN:
            rc = libxl__qmp_pci_del(gc, domid, pcidev);
            break;
        default:
            rc = ERROR_INVAL;
            goto out_fail;
        }
        if (rc) {
            rc = ERROR_FAIL;
            goto out_fail;
        }
        break;
    case LIBXL_DOMAIN_TYPE_PV:
    {
        char *sysfs_path = libxl__sprintf(gc, SYSFS_PCI_DEV"/"PCI_BDF"/resource", pcidev->domain,
                                         pcidev->bus, pcidev->dev, pcidev->func);
        FILE *f = fopen(sysfs_path, "r");
        unsigned int start = 0, end = 0, flags = 0, size = 0;
        int irq = 0;
        int i;

        if (f == NULL) {
            LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "Couldn't open %s", sysfs_path);
            goto skip1;
        }
        for (i = 0; i < PROC_PCI_NUM_RESOURCES; i++) {
            if (fscanf(f, "0x%x 0x%x 0x%x\n", &start, &end, &flags) != 3)
                continue;
            size = end - start + 1;
            if (start) {
                if (flags & PCI_BAR_IO) {
                    rc = xc_domain_ioport_permission(ctx->xch, domid, start, size, 0);
                    if (rc < 0)
                        LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "xc_domain_ioport_permission error 0x%x/0x%x", start, size);
                } else {
                    rc = xc_domain_iomem_permission(ctx->xch, domid, start>>XC_PAGE_SHIFT,
                                                    (size+(XC_PAGE_SIZE-1))>>XC_PAGE_SHIFT, 0);
                    if (rc < 0)
                        LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "xc_domain_iomem_permission error 0x%x/0x%x", start, size);
                }
            }
        }
        fclose(f);
skip1:
        sysfs_path = libxl__sprintf(gc, SYSFS_PCI_DEV"/"PCI_BDF"/irq", pcidev->domain,
                                   pcidev->bus, pcidev->dev, pcidev->func);
        f = fopen(sysfs_path, "r");
        if (f == NULL) {
            LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "Couldn't open %s", sysfs_path);
            goto out;
        }
        if ((fscanf(f, "%u", &irq) == 1) && irq) {
            rc = xc_physdev_unmap_pirq(ctx->xch, domid, irq);
            if (rc < 0) {
                LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "xc_physdev_unmap_pirq irq=%d", irq);
            }
            rc = xc_domain_irq_permission(ctx->xch, domid, irq, 0);
            if (rc < 0) {
                LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "xc_domain_irq_permission irq=%d", irq);
            }
        }
        fclose(f);
        break;
    }
    default:
        abort();
    }
out:
    /* don't do multiple resets while some functions are still passed through */
    if ( (pcidev->vdevfn & 0x7) == 0 ) {
        libxl__device_pci_reset(gc, pcidev->domain, pcidev->bus, pcidev->dev, pcidev->func);
    }

    if (!libxl_is_stubdom(ctx, domid, NULL)) {
        rc = xc_deassign_device(ctx->xch, domid, pcidev_encode_bdf(pcidev));
        if (rc < 0 && (hvm || errno != ENOSYS))
            LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "xc_deassign_device failed");
    }

    stubdomid = libxl_get_stubdom_id(ctx, domid);
    if (stubdomid != 0) {
        libxl_device_pci pcidev_s = *pcidev;
        libxl__device_pci_remove_common(gc, stubdomid, &pcidev_s, force);
    }

    libxl__device_pci_remove_xenstore(gc, domid, pcidev);

    rc = 0;
out_fail:
    free(assigned);
    return rc;

}

static int libxl__device_pci_remove_common(libxl__gc *gc, uint32_t domid,
                                           libxl_device_pci *pcidev, int force)
{
    unsigned int orig_vdev, pfunc_mask;
    int i, rc;

    orig_vdev = pcidev->vdevfn & ~7U;

    if ( pcidev->vfunc_mask == LIBXL_PCI_FUNC_ALL ) {
        if ( pci_multifunction_check(gc, pcidev, &pfunc_mask) ) {
            rc = ERROR_FAIL;
            goto out;
        }
        pcidev->vfunc_mask &= pfunc_mask;
    }else{
        pfunc_mask = (1 << pcidev->func);
    }

    for(rc = 0, i = 7; i >= 0; --i) {
        if ( (1 << i) & pfunc_mask ) {
            if ( pcidev->vfunc_mask == pfunc_mask ) {
                pcidev->func = i;
                pcidev->vdevfn = orig_vdev | i;
            }else{
                pcidev->vdevfn = orig_vdev;
            }
            if ( do_pci_remove(gc, domid, pcidev, force) )
                rc = ERROR_FAIL;
        }
    }

out:
    return rc;
}

int libxl_device_pci_remove(libxl_ctx *ctx, uint32_t domid,
                            libxl_device_pci *pcidev,
                            const libxl_asyncop_how *ao_how)

{
    AO_CREATE(ctx, domid, ao_how);
    int rc;

    rc = libxl__device_pci_remove_common(gc, domid, pcidev, 0);

    libxl__ao_complete(egc, ao, rc);
    return AO_INPROGRESS;
}

int libxl_device_pci_destroy(libxl_ctx *ctx, uint32_t domid,
                             libxl_device_pci *pcidev,
                             const libxl_asyncop_how *ao_how)
{
    AO_CREATE(ctx, domid, ao_how);
    int rc;

    rc = libxl__device_pci_remove_common(gc, domid, pcidev, 1);

    libxl__ao_complete(egc, ao, rc);
    return AO_INPROGRESS;
}

static void libxl__device_pci_from_xs_be(libxl__gc *gc,
                                         const char *be_path,
                                         libxl_device_pci *pci,
                                         int nr)
{
    char *s;
    unsigned int domain = 0, bus = 0, dev = 0, func = 0, vdevfn = 0;

    s = libxl__xs_read(gc, XBT_NULL, libxl__sprintf(gc, "%s/dev-%d", be_path, nr));
    sscanf(s, PCI_BDF, &domain, &bus, &dev, &func);

    s = libxl__xs_read(gc, XBT_NULL, libxl__sprintf(gc, "%s/vdevfn-%d", be_path, nr));
    if (s)
        vdevfn = strtol(s, (char **) NULL, 16);

    pcidev_struct_fill(pci, domain, bus, dev, func, vdevfn);

    s = libxl__xs_read(gc, XBT_NULL, libxl__sprintf(gc, "%s/opts-%d", be_path, nr));
    if (s) {
        char *saveptr;
        char *p = strtok_r(s, ",=", &saveptr);
        do {
            while (*p == ' ')
                p++;
            if (!strcmp(p, "msitranslate")) {
                p = strtok_r(NULL, ",=", &saveptr);
                pci->msitranslate = atoi(p);
            } else if (!strcmp(p, "power_mgmt")) {
                p = strtok_r(NULL, ",=", &saveptr);
                pci->power_mgmt = atoi(p);
            } else if (!strcmp(p, "permissive")) {
                p = strtok_r(NULL, ",=", &saveptr);
                pci->permissive = atoi(p);
            }
        } while ((p = strtok_r(NULL, ",=", &saveptr)) != NULL);
    }
}

libxl_device_pci *libxl_device_pci_list(libxl_ctx *ctx, uint32_t domid, int *num)
{
    GC_INIT(ctx);
    char *be_path, *num_devs;
    int n, i;
    libxl_device_pci *pcidevs = NULL;

    *num = 0;

    be_path = libxl__sprintf(gc, "%s/backend/pci/%d/0", libxl__xs_get_dompath(gc, 0), domid);
    num_devs = libxl__xs_read(gc, XBT_NULL, libxl__sprintf(gc, "%s/num_devs", be_path));
    if (!num_devs)
        goto out;

    n = atoi(num_devs);
    pcidevs = calloc(n, sizeof(libxl_device_pci));

    for (i = 0; i < n; i++)
        libxl__device_pci_from_xs_be(gc, be_path, pcidevs + i, i);

    *num = n;
out:
    GC_FREE;
    return pcidevs;
}

int libxl__device_pci_destroy_all(libxl__gc *gc, uint32_t domid)
{
    libxl_ctx *ctx = libxl__gc_owner(gc);
    libxl_device_pci *pcidevs;
    int num, i, rc = 0;

    pcidevs = libxl_device_pci_list(ctx, domid, &num);
    if ( pcidevs == NULL )
        return 0;

    for (i = 0; i < num; i++) {
        /* Force remove on shutdown since, on HVM, qemu will not always
         * respond to SCI interrupt because the guest kernel has shut down the
         * devices by the time we even get here!
         */
        if (libxl__device_pci_remove_common(gc, domid, pcidevs + i, 1) < 0)
            rc = ERROR_FAIL;
    }

    free(pcidevs);
    return 0;
}

/*
 * Local variables:
 * mode: C
 * c-basic-offset: 4
 * indent-tabs-mode: nil
 * End:
 */
