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 "hw/i386/pc.h"
  17 #include "qemu/sockets.h"
  18 #include "virtio-9p.h"
  19 #include "fsdev/qemu-fsdev.h"
  20 #include "9p-xattr.h"
  21 #include "coth.h"
  22 #include "hw/virtio/virtio-access.h"
  23 #include "qemu/iov.h"
  24
  25 void virtio_9p_push_and_notify(V9fsPDU *pdu)
  26 {
  27     V9fsState *s = pdu->s;
  28     V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
  29     VirtQueueElement *elem = &v->elems[pdu->idx];
  30
  31     /* push onto queue and notify */
  32     virtqueue_push(v->vq, elem, pdu->size);
  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 = &v->elems[pdu->idx];
  52
  53         len = virtqueue_pop(vq, elem);
  54         if (!len) {
  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         len = iov_to_buf(elem->out_sg, elem->out_num, 0,
  63                          &out, sizeof out);
  64         BUG_ON(len != sizeof out);
  65
  66         pdu->size = le32_to_cpu(out.size_le);
  67
  68         pdu->id = out.id;
  69         pdu->tag = le16_to_cpu(out.tag_le);
  70
  71         qemu_co_queue_init(&pdu->complete);
  72         pdu_submit(pdu);
  73     }
  74 }
  75
  76 static uint64_t virtio_9p_get_features(VirtIODevice *vdev, uint64_t features,
  77                                        Error **errp)
  78 {
  79     virtio_add_feature(&features, VIRTIO_9P_MOUNT_TAG);
  80     return features;
  81 }
  82
  83 static void virtio_9p_get_config(VirtIODevice *vdev, uint8_t *config)
  84 {
  85     int len;
  86     struct virtio_9p_config *cfg;
  87     V9fsVirtioState *v = VIRTIO_9P(vdev);
  88     V9fsState *s = &v->state;
  89
  90     len = strlen(s->tag);
  91     cfg = g_malloc0(sizeof(struct virtio_9p_config) + len);
  92     virtio_stw_p(vdev, &cfg->tag_len, len);
  93     /* We don't copy the terminating null to config space */
  94     memcpy(cfg->tag, s->tag, len);
  95     memcpy(config, cfg, v->config_size);
  96     g_free(cfg);
  97 }
  98
  99 static void virtio_9p_save(QEMUFile *f, void *opaque)
 100 {
 101     virtio_save(VIRTIO_DEVICE(opaque), f);
 102 }
 103
 104 static int virtio_9p_load(QEMUFile *f, void *opaque, int version_id)
 105 {
 106     return virtio_load(VIRTIO_DEVICE(opaque), f, version_id);
 107 }
 108
 109 static void virtio_9p_device_realize(DeviceState *dev, Error **errp)
 110 {
 111     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 112     V9fsVirtioState *v = VIRTIO_9P(dev);
 113     V9fsState *s = &v->state;
 114
 115     if (v9fs_device_realize_common(s, errp)) {
 116         goto out;
 117     }
 118
 119     v->config_size = sizeof(struct virtio_9p_config) + strlen(s->fsconf.tag);
 120     virtio_init(vdev, "virtio-9p", VIRTIO_ID_9P, v->config_size);
 121     v->vq = virtio_add_queue(vdev, MAX_REQ, handle_9p_output);
 122     register_savevm(dev, "virtio-9p", -1, 1, virtio_9p_save, virtio_9p_load, v);
 123
 124 out:
 125     return;
 126 }
 127
 128 static void virtio_9p_device_unrealize(DeviceState *dev, Error **errp)
 129 {
 130     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 131     V9fsVirtioState *v = VIRTIO_9P(dev);
 132     V9fsState *s = &v->state;
 133
 134     virtio_cleanup(vdev);
 135     unregister_savevm(dev, "virtio-9p", v);
 136     v9fs_device_unrealize_common(s, errp);
 137 }
 138
 139 ssize_t virtio_pdu_vmarshal(V9fsPDU *pdu, size_t offset,
 140                             const char *fmt, va_list ap)
 141 {
 142     V9fsState *s = pdu->s;
 143     V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
 144     VirtQueueElement *elem = &v->elems[pdu->idx];
 145
 146     return v9fs_iov_vmarshal(elem->in_sg, elem->in_num, offset, 1, fmt, ap);
 147 }
 148
 149 ssize_t virtio_pdu_vunmarshal(V9fsPDU *pdu, size_t offset,
 150                               const char *fmt, va_list ap)
 151 {
 152     V9fsState *s = pdu->s;
 153     V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
 154     VirtQueueElement *elem = &v->elems[pdu->idx];
 155
 156     return v9fs_iov_vunmarshal(elem->out_sg, elem->out_num, offset, 1, fmt, ap);
 157 }
 158
 159 void virtio_init_iov_from_pdu(V9fsPDU *pdu, struct iovec **piov,
 160                               unsigned int *pniov, bool is_write)
 161 {
 162     V9fsState *s = pdu->s;
 163     V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
 164     VirtQueueElement *elem = &v->elems[pdu->idx];
 165
 166     if (is_write) {
 167         *piov = elem->out_sg;
 168         *pniov = elem->out_num;
 169     } else {
 170         *piov = elem->in_sg;
 171         *pniov = elem->in_num;
 172     }
 173 }
 174
 175 /* virtio-9p device */
 176
 177 static Property virtio_9p_properties[] = {
 178     DEFINE_PROP_STRING("mount_tag", V9fsVirtioState, state.fsconf.tag),
 179     DEFINE_PROP_STRING("fsdev", V9fsVirtioState, state.fsconf.fsdev_id),
 180     DEFINE_PROP_END_OF_LIST(),
 181 };
 182
 183 static void virtio_9p_class_init(ObjectClass *klass, void *data)
 184 {
 185     DeviceClass *dc = DEVICE_CLASS(klass);
 186     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 187
 188     dc->props = virtio_9p_properties;
 189     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 190     vdc->realize = virtio_9p_device_realize;
 191     vdc->unrealize = virtio_9p_device_unrealize;
 192     vdc->get_features = virtio_9p_get_features;
 193     vdc->get_config = virtio_9p_get_config;
 194 }
 195
 196 static const TypeInfo virtio_device_info = {
 197     .name = TYPE_VIRTIO_9P,
 198     .parent = TYPE_VIRTIO_DEVICE,
 199     .instance_size = sizeof(V9fsVirtioState),
 200     .class_init = virtio_9p_class_init,
 201 };
 202
 203 static void virtio_9p_register_types(void)
 204 {
 205     type_register_static(&virtio_device_info);
 206 }
 207
 208 type_init(virtio_9p_register_types)