xref: /openbmc/qemu/hw/9pfs/virtio-9p-device.c (revision c71c3e99)
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.h"
15 #include "hw/pc.h"
16 #include "qemu/sockets.h"
17 #include "virtio-9p.h"
18 #include "fsdev/qemu-fsdev.h"
19 #include "virtio-9p-device.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 }
139