hw/9pfs/virtio-9p-device.c

   1 /*
   2  * Virtio 9p backend
   3  *
   4  * Copyright IBM, Corp. 2010
   5  *
   6  * Authors:
   7  *  Anthony Liguori   <aliguori@us.ibm.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2.  See
  10  * the COPYING file in the top-level directory.
  11  *
  12  */
  13
  14 #include "hw/virtio/virtio.h"
  15 #include "hw/virtio/virtio-9p.h"
  16 #include "hw/i386/pc.h"
  17 #include "qemu/sockets.h"
  18 #include "virtio-9p.h"
  19 #include "fsdev/qemu-fsdev.h"
  20 #include "virtio-9p-xattr.h"
  21 #include "virtio-9p-coth.h"
  22
  23 static uint32_t virtio_9p_get_features(VirtIODevice *vdev, uint32_t features)
  24 {
  25     features |= 1 << VIRTIO_9P_MOUNT_TAG;
  26     return features;
  27 }
  28
  29 static V9fsState *to_virtio_9p(VirtIODevice *vdev)
  30 {
  31     return (V9fsState *)vdev;
  32 }
  33
  34 static void virtio_9p_get_config(VirtIODevice *vdev, uint8_t *config)
  35 {
  36     int len;
  37     struct virtio_9p_config *cfg;
  38     V9fsState *s = to_virtio_9p(vdev);
  39
  40     len = strlen(s->tag);
  41     cfg = g_malloc0(sizeof(struct virtio_9p_config) + len);
  42     stw_raw(&cfg->tag_len, len);
  43     /* We don't copy the terminating null to config space */
  44     memcpy(cfg->tag, s->tag, len);
  45     memcpy(config, cfg, s->config_size);
  46     g_free(cfg);
  47 }
  48
  49 VirtIODevice *virtio_9p_init(DeviceState *dev, V9fsConf *conf)
  50 {
  51     V9fsState *s;
  52     int i, len;
  53     struct stat stat;
  54     FsDriverEntry *fse;
  55     V9fsPath path;
  56
  57     s = (V9fsState *)virtio_common_init("virtio-9p",
  58                                     VIRTIO_ID_9P,
  59                                     sizeof(struct virtio_9p_config)+
  60                                     MAX_TAG_LEN,
  61                                     sizeof(V9fsState));
  62     /* initialize pdu allocator */
  63     QLIST_INIT(&s->free_list);
  64     QLIST_INIT(&s->active_list);
  65     for (i = 0; i < (MAX_REQ - 1); i++) {
  66         QLIST_INSERT_HEAD(&s->free_list, &s->pdus[i], next);
  67     }
  68
  69     s->vq = virtio_add_queue(&s->vdev, MAX_REQ, handle_9p_output);
  70
  71     fse = get_fsdev_fsentry(conf->fsdev_id);
  72
  73     if (!fse) {
  74         /* We don't have a fsdev identified by fsdev_id */
  75         fprintf(stderr, "Virtio-9p device couldn't find fsdev with the "
  76                 "id = %s\n", conf->fsdev_id ? conf->fsdev_id : "NULL");
  77         exit(1);
  78     }
  79
  80     if (!conf->tag) {
  81         /* we haven't specified a mount_tag */
  82         fprintf(stderr, "fsdev with id %s needs mount_tag arguments\n",
  83                 conf->fsdev_id);
  84         exit(1);
  85     }
  86
  87     s->ctx.export_flags = fse->export_flags;
  88     s->ctx.fs_root = g_strdup(fse->path);
  89     s->ctx.exops.get_st_gen = NULL;
  90     len = strlen(conf->tag);
  91     if (len > MAX_TAG_LEN - 1) {
  92         fprintf(stderr, "mount tag '%s' (%d bytes) is longer than "
  93                 "maximum (%d bytes)", conf->tag, len, MAX_TAG_LEN - 1);
  94         exit(1);
  95     }
  96
  97     s->tag = g_strdup(conf->tag);
  98     s->ctx.uid = -1;
  99
 100     s->ops = fse->ops;
 101     s->vdev.get_features = virtio_9p_get_features;
 102     s->config_size = sizeof(struct virtio_9p_config) + len;
 103     s->vdev.get_config = virtio_9p_get_config;
 104     s->fid_list = NULL;
 105     qemu_co_rwlock_init(&s->rename_lock);
 106
 107     if (s->ops->init(&s->ctx) < 0) {
 108         fprintf(stderr, "Virtio-9p Failed to initialize fs-driver with id:%s"
 109                 " and export path:%s\n", conf->fsdev_id, s->ctx.fs_root);
 110         exit(1);
 111     }
 112     if (v9fs_init_worker_threads() < 0) {
 113         fprintf(stderr, "worker thread initialization failed\n");
 114         exit(1);
 115     }
 116
 117     /*
 118      * Check details of export path, We need to use fs driver
 119      * call back to do that. Since we are in the init path, we don't
 120      * use co-routines here.
 121      */
 122     v9fs_path_init(&path);
 123     if (s->ops->name_to_path(&s->ctx, NULL, "/", &path) < 0) {
 124         fprintf(stderr,
 125                 "error in converting name to path %s", strerror(errno));
 126         exit(1);
 127     }
 128     if (s->ops->lstat(&s->ctx, &path, &stat)) {
 129         fprintf(stderr, "share path %s does not exist\n", fse->path);
 130         exit(1);
 131     } else if (!S_ISDIR(stat.st_mode)) {
 132         fprintf(stderr, "share path %s is not a directory\n", fse->path);
 133         exit(1);
 134     }
 135     v9fs_path_free(&path);
 136
 137     return &s->vdev;
 138 }