xref: /openbmc/qemu/hw/9pfs/virtio-9p-device.c (revision bd50530a)
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 #include "hw/virtio/virtio-access.h"
23 
24 static uint64_t virtio_9p_get_features(VirtIODevice *vdev, uint64_t features)
25 {
26     virtio_add_feature(&features, VIRTIO_9P_MOUNT_TAG);
27     return features;
28 }
29 
30 static void virtio_9p_get_config(VirtIODevice *vdev, uint8_t *config)
31 {
32     int len;
33     struct virtio_9p_config *cfg;
34     V9fsState *s = VIRTIO_9P(vdev);
35 
36     len = strlen(s->tag);
37     cfg = g_malloc0(sizeof(struct virtio_9p_config) + len);
38     virtio_stw_p(vdev, &cfg->tag_len, len);
39     /* We don't copy the terminating null to config space */
40     memcpy(cfg->tag, s->tag, len);
41     memcpy(config, cfg, s->config_size);
42     g_free(cfg);
43 }
44 
45 static void virtio_9p_device_realize(DeviceState *dev, Error **errp)
46 {
47     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
48     V9fsState *s = VIRTIO_9P(dev);
49     int i, len;
50     struct stat stat;
51     FsDriverEntry *fse;
52     V9fsPath path;
53 
54     virtio_init(vdev, "virtio-9p", VIRTIO_ID_9P,
55                 sizeof(struct virtio_9p_config) + MAX_TAG_LEN);
56 
57     /* initialize pdu allocator */
58     QLIST_INIT(&s->free_list);
59     QLIST_INIT(&s->active_list);
60     for (i = 0; i < (MAX_REQ - 1); i++) {
61         QLIST_INSERT_HEAD(&s->free_list, &s->pdus[i], next);
62     }
63 
64     s->vq = virtio_add_queue(vdev, MAX_REQ, handle_9p_output);
65 
66     v9fs_path_init(&path);
67 
68     fse = get_fsdev_fsentry(s->fsconf.fsdev_id);
69 
70     if (!fse) {
71         /* We don't have a fsdev identified by fsdev_id */
72         error_setg(errp, "Virtio-9p device couldn't find fsdev with the "
73                    "id = %s",
74                    s->fsconf.fsdev_id ? s->fsconf.fsdev_id : "NULL");
75         goto out;
76     }
77 
78     if (!s->fsconf.tag) {
79         /* we haven't specified a mount_tag */
80         error_setg(errp, "fsdev with id %s needs mount_tag arguments",
81                    s->fsconf.fsdev_id);
82         goto out;
83     }
84 
85     s->ctx.export_flags = fse->export_flags;
86     s->ctx.fs_root = g_strdup(fse->path);
87     s->ctx.exops.get_st_gen = NULL;
88     len = strlen(s->fsconf.tag);
89     if (len > MAX_TAG_LEN - 1) {
90         error_setg(errp, "mount tag '%s' (%d bytes) is longer than "
91                    "maximum (%d bytes)", s->fsconf.tag, len, MAX_TAG_LEN - 1);
92         goto out;
93     }
94 
95     s->tag = g_strdup(s->fsconf.tag);
96     s->ctx.uid = -1;
97 
98     s->ops = fse->ops;
99     s->config_size = sizeof(struct virtio_9p_config) + len;
100     s->fid_list = NULL;
101     qemu_co_rwlock_init(&s->rename_lock);
102 
103     if (s->ops->init(&s->ctx) < 0) {
104         error_setg(errp, "Virtio-9p Failed to initialize fs-driver with id:%s"
105                    " and export path:%s", s->fsconf.fsdev_id, s->ctx.fs_root);
106         goto out;
107     }
108     if (v9fs_init_worker_threads() < 0) {
109         error_setg(errp, "worker thread initialization failed");
110         goto out;
111     }
112 
113     /*
114      * Check details of export path, We need to use fs driver
115      * call back to do that. Since we are in the init path, we don't
116      * use co-routines here.
117      */
118     if (s->ops->name_to_path(&s->ctx, NULL, "/", &path) < 0) {
119         error_setg(errp,
120                    "error in converting name to path %s", strerror(errno));
121         goto out;
122     }
123     if (s->ops->lstat(&s->ctx, &path, &stat)) {
124         error_setg(errp, "share path %s does not exist", fse->path);
125         goto out;
126     } else if (!S_ISDIR(stat.st_mode)) {
127         error_setg(errp, "share path %s is not a directory", fse->path);
128         goto out;
129     }
130     v9fs_path_free(&path);
131 
132     return;
133 out:
134     g_free(s->ctx.fs_root);
135     g_free(s->tag);
136     virtio_cleanup(vdev);
137     v9fs_path_free(&path);
138 }
139 
140 /* virtio-9p device */
141 
142 static Property virtio_9p_properties[] = {
143     DEFINE_PROP_STRING("mount_tag", V9fsState, fsconf.tag),
144     DEFINE_PROP_STRING("fsdev", V9fsState, fsconf.fsdev_id),
145     DEFINE_PROP_END_OF_LIST(),
146 };
147 
148 static void virtio_9p_class_init(ObjectClass *klass, void *data)
149 {
150     DeviceClass *dc = DEVICE_CLASS(klass);
151     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
152 
153     dc->props = virtio_9p_properties;
154     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
155     vdc->realize = virtio_9p_device_realize;
156     vdc->get_features = virtio_9p_get_features;
157     vdc->get_config = virtio_9p_get_config;
158 }
159 
160 static const TypeInfo virtio_device_info = {
161     .name = TYPE_VIRTIO_9P,
162     .parent = TYPE_VIRTIO_DEVICE,
163     .instance_size = sizeof(V9fsState),
164     .class_init = virtio_9p_class_init,
165 };
166 
167 static void virtio_9p_register_types(void)
168 {
169     type_register_static(&virtio_device_info);
170 }
171 
172 type_init(virtio_9p_register_types)
173