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/virtio/virtio-access.h"
  21 #include "qemu/iov.h"
  22
  23 void virtio_9p_push_and_notify(V9fsPDU *pdu)
  24 {
  25     V9fsState *s = pdu->s;
  26     V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
  27     VirtQueueElement *elem = v->elems[pdu->idx];
  28
  29     /* push onto queue and notify */
  30     virtqueue_push(v->vq, elem, pdu->size);
  31     g_free(elem);
  32     v->elems[pdu->idx] = NULL;
  33
  34     /* FIXME: we should batch these completions */
  35     virtio_notify(VIRTIO_DEVICE(v), v->vq);
  36 }
  37
  38 static void handle_9p_output(VirtIODevice *vdev, VirtQueue *vq)
  39 {
  40     V9fsVirtioState *v = (V9fsVirtioState *)vdev;
  41     V9fsState *s = &v->state;
  42     V9fsPDU *pdu;
  43     ssize_t len;
  44
  45     while ((pdu = pdu_alloc(s))) {
  46         struct {
  47             uint32_t size_le;
  48             uint8_t id;
  49             uint16_t tag_le;
  50         } QEMU_PACKED out;
  51         VirtQueueElement *elem;
  52
  53         elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
  54         if (!elem) {
  55             pdu_free(pdu);
  56             break;
  57         }
  58
  59         BUG_ON(elem->out_num == 0 || elem->in_num == 0);
  60         QEMU_BUILD_BUG_ON(sizeof out != 7);
  61
  62         v->elems[pdu->idx] = elem;
  63         len = iov_to_buf(elem->out_sg, elem->out_num, 0,
  64                          &out, sizeof out);
  65         BUG_ON(len != sizeof out);
  66
  67         pdu->size = le32_to_cpu(out.size_le);
  68
  69         pdu->id = out.id;
  70         pdu->tag = le16_to_cpu(out.tag_le);
  71
  72         qemu_co_queue_init(&pdu->complete);
  73         pdu_submit(pdu);
  74     }
  75 }
  76
  77 static uint64_t virtio_9p_get_features(VirtIODevice *vdev, uint64_t features,
  78                                        Error **errp)
  79 {
  80     virtio_add_feature(&features, VIRTIO_9P_MOUNT_TAG);
  81     return features;
  82 }
  83
  84 static void virtio_9p_get_config(VirtIODevice *vdev, uint8_t *config)
  85 {
  86     int len;
  87     struct virtio_9p_config *cfg;
  88     V9fsVirtioState *v = VIRTIO_9P(vdev);
  89     V9fsState *s = &v->state;
  90
  91     len = strlen(s->tag);
  92     cfg = g_malloc0(sizeof(struct virtio_9p_config) + len);
  93     virtio_stw_p(vdev, &cfg->tag_len, len);
  94     /* We don't copy the terminating null to config space */
  95     memcpy(cfg->tag, s->tag, len);
  96     memcpy(config, cfg, v->config_size);
  97     g_free(cfg);
  98 }
  99
 100 static void virtio_9p_save(QEMUFile *f, void *opaque)
 101 {
 102     virtio_save(VIRTIO_DEVICE(opaque), f);
 103 }
 104
 105 static int virtio_9p_load(QEMUFile *f, void *opaque, int version_id)
 106 {
 107     return virtio_load(VIRTIO_DEVICE(opaque), f, version_id);
 108 }
 109
 110 static void virtio_9p_device_realize(DeviceState *dev, Error **errp)
 111 {
 112     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 113     V9fsVirtioState *v = VIRTIO_9P(dev);
 114     V9fsState *s = &v->state;
 115
 116     if (v9fs_device_realize_common(s, errp)) {
 117         goto out;
 118     }
 119
 120     v->config_size = sizeof(struct virtio_9p_config) + strlen(s->fsconf.tag);
 121     virtio_init(vdev, "virtio-9p", VIRTIO_ID_9P, v->config_size);
 122     v->vq = virtio_add_queue(vdev, MAX_REQ, handle_9p_output);
 123     register_savevm(dev, "virtio-9p", -1, 1, virtio_9p_save, virtio_9p_load, v);
 124
 125 out:
 126     return;
 127 }
 128
 129 static void virtio_9p_device_unrealize(DeviceState *dev, Error **errp)
 130 {
 131     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 132     V9fsVirtioState *v = VIRTIO_9P(dev);
 133     V9fsState *s = &v->state;
 134
 135     virtio_cleanup(vdev);
 136     unregister_savevm(dev, "virtio-9p", v);
 137     v9fs_device_unrealize_common(s, errp);
 138 }
 139
 140 ssize_t virtio_pdu_vmarshal(V9fsPDU *pdu, size_t offset,
 141                             const char *fmt, va_list ap)
 142 {
 143     V9fsState *s = pdu->s;
 144     V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
 145     VirtQueueElement *elem = v->elems[pdu->idx];
 146
 147     return v9fs_iov_vmarshal(elem->in_sg, elem->in_num, offset, 1, fmt, ap);
 148 }
 149
 150 ssize_t virtio_pdu_vunmarshal(V9fsPDU *pdu, size_t offset,
 151                               const char *fmt, va_list ap)
 152 {
 153     V9fsState *s = pdu->s;
 154     V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
 155     VirtQueueElement *elem = v->elems[pdu->idx];
 156
 157     return v9fs_iov_vunmarshal(elem->out_sg, elem->out_num, offset, 1, fmt, ap);
 158 }
 159
 160 void virtio_init_iov_from_pdu(V9fsPDU *pdu, struct iovec **piov,
 161                               unsigned int *pniov, bool is_write)
 162 {
 163     V9fsState *s = pdu->s;
 164     V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
 165     VirtQueueElement *elem = v->elems[pdu->idx];
 166
 167     if (is_write) {
 168         *piov = elem->out_sg;
 169         *pniov = elem->out_num;
 170     } else {
 171         *piov = elem->in_sg;
 172         *pniov = elem->in_num;
 173     }
 174 }
 175
 176 /* virtio-9p device */
 177
 178 static Property virtio_9p_properties[] = {
 179     DEFINE_PROP_STRING("mount_tag", V9fsVirtioState, state.fsconf.tag),
 180     DEFINE_PROP_STRING("fsdev", V9fsVirtioState, state.fsconf.fsdev_id),
 181     DEFINE_PROP_END_OF_LIST(),
 182 };
 183
 184 static void virtio_9p_class_init(ObjectClass *klass, void *data)
 185 {
 186     DeviceClass *dc = DEVICE_CLASS(klass);
 187     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 188
 189     dc->props = virtio_9p_properties;
 190     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 191     vdc->realize = virtio_9p_device_realize;
 192     vdc->unrealize = virtio_9p_device_unrealize;
 193     vdc->get_features = virtio_9p_get_features;
 194     vdc->get_config = virtio_9p_get_config;
 195 }
 196
 197 static const TypeInfo virtio_device_info = {
 198     .name = TYPE_VIRTIO_9P,
 199     .parent = TYPE_VIRTIO_DEVICE,
 200     .instance_size = sizeof(V9fsVirtioState),
 201     .class_init = virtio_9p_class_init,
 202 };
 203
 204 static void virtio_9p_register_types(void)
 205 {
 206     type_register_static(&virtio_device_info);
 207 }
 208
 209 type_init(virtio_9p_register_types)