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 "qemu/osdep.h"
  15 #include "hw/virtio/virtio.h"
  16 #include "qemu/sockets.h"
  17 #include "virtio-9p.h"
  18 #include "fsdev/qemu-fsdev.h"
  19 #include "coth.h"
  20 #include "hw/qdev-properties.h"
  21 #include "hw/virtio/virtio-access.h"
  22 #include "qemu/iov.h"
  23 #include "qemu/module.h"
  24 #include "sysemu/qtest.h"
  25
  26 static void virtio_9p_push_and_notify(V9fsPDU *pdu)
  27 {
  28     V9fsState *s = pdu->s;
  29     V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
  30     VirtQueueElement *elem = v->elems[pdu->idx];
  31
  32     /* push onto queue and notify */
  33     virtqueue_push(v->vq, elem, pdu->size);
  34     g_free(elem);
  35     v->elems[pdu->idx] = NULL;
  36
  37     /* FIXME: we should batch these completions */
  38     virtio_notify(VIRTIO_DEVICE(v), v->vq);
  39 }
  40
  41 static void handle_9p_output(VirtIODevice *vdev, VirtQueue *vq)
  42 {
  43     V9fsVirtioState *v = (V9fsVirtioState *)vdev;
  44     V9fsState *s = &v->state;
  45     V9fsPDU *pdu;
  46     ssize_t len;
  47     VirtQueueElement *elem;
  48
  49     while ((pdu = pdu_alloc(s))) {
  50         P9MsgHeader out;
  51
  52         elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
  53         if (!elem) {
  54             goto out_free_pdu;
  55         }
  56
  57         if (iov_size(elem->in_sg, elem->in_num) < 7) {
  58             virtio_error(vdev,
  59                          "The guest sent a VirtFS request without space for "
  60                          "the reply");
  61             goto out_free_req;
  62         }
  63
  64         len = iov_to_buf(elem->out_sg, elem->out_num, 0, &out, 7);
  65         if (len != 7) {
  66             virtio_error(vdev, "The guest sent a malformed VirtFS request: "
  67                          "header size is %zd, should be 7", len);
  68             goto out_free_req;
  69         }
  70
  71         v->elems[pdu->idx] = elem;
  72
  73         pdu_submit(pdu, &out);
  74     }
  75
  76     return;
  77
  78 out_free_req:
  79     virtqueue_detach_element(vq, elem, 0);
  80     g_free(elem);
  81 out_free_pdu:
  82     pdu_free(pdu);
  83 }
  84
  85 static uint64_t virtio_9p_get_features(VirtIODevice *vdev, uint64_t features,
  86                                        Error **errp)
  87 {
  88     virtio_add_feature(&features, VIRTIO_9P_MOUNT_TAG);
  89     return features;
  90 }
  91
  92 static void virtio_9p_get_config(VirtIODevice *vdev, uint8_t *config)
  93 {
  94     int len;
  95     struct virtio_9p_config *cfg;
  96     V9fsVirtioState *v = VIRTIO_9P(vdev);
  97     V9fsState *s = &v->state;
  98
  99     len = strlen(s->tag);
 100     cfg = g_malloc0(sizeof(struct virtio_9p_config) + len);
 101     virtio_stw_p(vdev, &cfg->tag_len, len);
 102     /* We don't copy the terminating null to config space */
 103     memcpy(cfg->tag, s->tag, len);
 104     memcpy(config, cfg, v->config_size);
 105     g_free(cfg);
 106 }
 107
 108 static void virtio_9p_reset(VirtIODevice *vdev)
 109 {
 110     V9fsVirtioState *v = (V9fsVirtioState *)vdev;
 111
 112     v9fs_reset(&v->state);
 113 }
 114
 115 static ssize_t virtio_pdu_vmarshal(V9fsPDU *pdu, size_t offset,
 116                                    const char *fmt, va_list ap)
 117 {
 118     V9fsState *s = pdu->s;
 119     V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
 120     VirtQueueElement *elem = v->elems[pdu->idx];
 121     ssize_t ret;
 122
 123     ret = v9fs_iov_vmarshal(elem->in_sg, elem->in_num, offset, 1, fmt, ap);
 124     if (ret < 0) {
 125         VirtIODevice *vdev = VIRTIO_DEVICE(v);
 126
 127         virtio_error(vdev, "Failed to encode VirtFS reply type %d",
 128                      pdu->id + 1);
 129     }
 130     return ret;
 131 }
 132
 133 static ssize_t virtio_pdu_vunmarshal(V9fsPDU *pdu, size_t offset,
 134                                      const char *fmt, va_list ap)
 135 {
 136     V9fsState *s = pdu->s;
 137     V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
 138     VirtQueueElement *elem = v->elems[pdu->idx];
 139     ssize_t ret;
 140
 141     ret = v9fs_iov_vunmarshal(elem->out_sg, elem->out_num, offset, 1, fmt, ap);
 142     if (ret < 0) {
 143         VirtIODevice *vdev = VIRTIO_DEVICE(v);
 144
 145         virtio_error(vdev, "Failed to decode VirtFS request type %d", pdu->id);
 146     }
 147     return ret;
 148 }
 149
 150 static void virtio_init_in_iov_from_pdu(V9fsPDU *pdu, struct iovec **piov,
 151                                         unsigned int *pniov, size_t size)
 152 {
 153     V9fsState *s = pdu->s;
 154     V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
 155     VirtQueueElement *elem = v->elems[pdu->idx];
 156     size_t buf_size = iov_size(elem->in_sg, elem->in_num);
 157
 158     if (buf_size < size) {
 159         VirtIODevice *vdev = VIRTIO_DEVICE(v);
 160
 161         virtio_error(vdev,
 162                      "VirtFS reply type %d needs %zu bytes, buffer has %zu",
 163                      pdu->id + 1, size, buf_size);
 164     }
 165
 166     *piov = elem->in_sg;
 167     *pniov = elem->in_num;
 168 }
 169
 170 static void virtio_init_out_iov_from_pdu(V9fsPDU *pdu, struct iovec **piov,
 171                                          unsigned int *pniov, size_t size)
 172 {
 173     V9fsState *s = pdu->s;
 174     V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
 175     VirtQueueElement *elem = v->elems[pdu->idx];
 176     size_t buf_size = iov_size(elem->out_sg, elem->out_num);
 177
 178     if (buf_size < size) {
 179         VirtIODevice *vdev = VIRTIO_DEVICE(v);
 180
 181         virtio_error(vdev,
 182                      "VirtFS request type %d needs %zu bytes, buffer has %zu",
 183                      pdu->id, size, buf_size);
 184     }
 185
 186     *piov = elem->out_sg;
 187     *pniov = elem->out_num;
 188 }
 189
 190 static const V9fsTransport virtio_9p_transport = {
 191     .pdu_vmarshal = virtio_pdu_vmarshal,
 192     .pdu_vunmarshal = virtio_pdu_vunmarshal,
 193     .init_in_iov_from_pdu = virtio_init_in_iov_from_pdu,
 194     .init_out_iov_from_pdu = virtio_init_out_iov_from_pdu,
 195     .push_and_notify = virtio_9p_push_and_notify,
 196 };
 197
 198 static void virtio_9p_device_realize(DeviceState *dev, Error **errp)
 199 {
 200     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 201     V9fsVirtioState *v = VIRTIO_9P(dev);
 202     V9fsState *s = &v->state;
 203     FsDriverEntry *fse = get_fsdev_fsentry(s->fsconf.fsdev_id);
 204
 205     if (qtest_enabled() && fse) {
 206         fse->export_flags |= V9FS_NO_PERF_WARN;
 207     }
 208
 209     if (v9fs_device_realize_common(s, &virtio_9p_transport, errp)) {
 210         return;
 211     }
 212
 213     v->config_size = sizeof(struct virtio_9p_config) + strlen(s->fsconf.tag);
 214     virtio_init(vdev, "virtio-9p", VIRTIO_ID_9P, v->config_size);
 215     v->vq = virtio_add_queue(vdev, MAX_REQ, handle_9p_output);
 216 }
 217
 218 static void virtio_9p_device_unrealize(DeviceState *dev)
 219 {
 220     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 221     V9fsVirtioState *v = VIRTIO_9P(dev);
 222     V9fsState *s = &v->state;
 223
 224     virtio_delete_queue(v->vq);
 225     virtio_cleanup(vdev);
 226     v9fs_device_unrealize_common(s);
 227 }
 228
 229 /* virtio-9p device */
 230
 231 static const VMStateDescription vmstate_virtio_9p = {
 232     .name = "virtio-9p",
 233     .minimum_version_id = 1,
 234     .version_id = 1,
 235     .fields = (VMStateField[]) {
 236         VMSTATE_VIRTIO_DEVICE,
 237         VMSTATE_END_OF_LIST()
 238     },
 239 };
 240
 241 static Property virtio_9p_properties[] = {
 242     DEFINE_PROP_STRING("mount_tag", V9fsVirtioState, state.fsconf.tag),
 243     DEFINE_PROP_STRING("fsdev", V9fsVirtioState, state.fsconf.fsdev_id),
 244     DEFINE_PROP_END_OF_LIST(),
 245 };
 246
 247 static void virtio_9p_class_init(ObjectClass *klass, void *data)
 248 {
 249     DeviceClass *dc = DEVICE_CLASS(klass);
 250     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 251
 252     device_class_set_props(dc, virtio_9p_properties);
 253     dc->vmsd = &vmstate_virtio_9p;
 254     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 255     vdc->realize = virtio_9p_device_realize;
 256     vdc->unrealize = virtio_9p_device_unrealize;
 257     vdc->get_features = virtio_9p_get_features;
 258     vdc->get_config = virtio_9p_get_config;
 259     vdc->reset = virtio_9p_reset;
 260 }
 261
 262 static const TypeInfo virtio_device_info = {
 263     .name = TYPE_VIRTIO_9P,
 264     .parent = TYPE_VIRTIO_DEVICE,
 265     .instance_size = sizeof(V9fsVirtioState),
 266     .class_init = virtio_9p_class_init,
 267 };
 268
 269 static void virtio_9p_register_types(void)
 270 {
 271     type_register_static(&virtio_device_info);
 272 }
 273
 274 type_init(virtio_9p_register_types)