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     g_free(elem);
  34     v->elems[pdu->idx] = NULL;
  35
  36     /* FIXME: we should batch these completions */
  37     virtio_notify(VIRTIO_DEVICE(v), v->vq);
  38 }
  39
  40 static void handle_9p_output(VirtIODevice *vdev, VirtQueue *vq)
  41 {
  42     V9fsVirtioState *v = (V9fsVirtioState *)vdev;
  43     V9fsState *s = &v->state;
  44     V9fsPDU *pdu;
  45     ssize_t len;
  46
  47     while ((pdu = pdu_alloc(s))) {
  48         struct {
  49             uint32_t size_le;
  50             uint8_t id;
  51             uint16_t tag_le;
  52         } QEMU_PACKED out;
  53         VirtQueueElement *elem;
  54
  55         elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
  56         if (!elem) {
  57             pdu_free(pdu);
  58             break;
  59         }
  60
  61         BUG_ON(elem->out_num == 0 || elem->in_num == 0);
  62         QEMU_BUILD_BUG_ON(sizeof out != 7);
  63
  64         v->elems[pdu->idx] = elem;
  65         len = iov_to_buf(elem->out_sg, elem->out_num, 0,
  66                          &out, sizeof out);
  67         BUG_ON(len != sizeof out);
  68
  69         pdu->size = le32_to_cpu(out.size_le);
  70
  71         pdu->id = out.id;
  72         pdu->tag = le16_to_cpu(out.tag_le);
  73
  74         qemu_co_queue_init(&pdu->complete);
  75         pdu_submit(pdu);
  76     }
  77 }
  78
  79 static uint64_t virtio_9p_get_features(VirtIODevice *vdev, uint64_t features,
  80                                        Error **errp)
  81 {
  82     virtio_add_feature(&features, VIRTIO_9P_MOUNT_TAG);
  83     return features;
  84 }
  85
  86 static void virtio_9p_get_config(VirtIODevice *vdev, uint8_t *config)
  87 {
  88     int len;
  89     struct virtio_9p_config *cfg;
  90     V9fsVirtioState *v = VIRTIO_9P(vdev);
  91     V9fsState *s = &v->state;
  92
  93     len = strlen(s->tag);
  94     cfg = g_malloc0(sizeof(struct virtio_9p_config) + len);
  95     virtio_stw_p(vdev, &cfg->tag_len, len);
  96     /* We don't copy the terminating null to config space */
  97     memcpy(cfg->tag, s->tag, len);
  98     memcpy(config, cfg, v->config_size);
  99     g_free(cfg);
 100 }
 101
 102 static void virtio_9p_save(QEMUFile *f, void *opaque)
 103 {
 104     virtio_save(VIRTIO_DEVICE(opaque), f);
 105 }
 106
 107 static int virtio_9p_load(QEMUFile *f, void *opaque, int version_id)
 108 {
 109     return virtio_load(VIRTIO_DEVICE(opaque), f, version_id);
 110 }
 111
 112 static void virtio_9p_device_realize(DeviceState *dev, Error **errp)
 113 {
 114     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 115     V9fsVirtioState *v = VIRTIO_9P(dev);
 116     V9fsState *s = &v->state;
 117
 118     if (v9fs_device_realize_common(s, errp)) {
 119         goto out;
 120     }
 121
 122     v->config_size = sizeof(struct virtio_9p_config) + strlen(s->fsconf.tag);
 123     virtio_init(vdev, "virtio-9p", VIRTIO_ID_9P, v->config_size);
 124     v->vq = virtio_add_queue(vdev, MAX_REQ, handle_9p_output);
 125     register_savevm(dev, "virtio-9p", -1, 1, virtio_9p_save, virtio_9p_load, v);
 126
 127 out:
 128     return;
 129 }
 130
 131 static void virtio_9p_device_unrealize(DeviceState *dev, Error **errp)
 132 {
 133     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 134     V9fsVirtioState *v = VIRTIO_9P(dev);
 135     V9fsState *s = &v->state;
 136
 137     virtio_cleanup(vdev);
 138     unregister_savevm(dev, "virtio-9p", v);
 139     v9fs_device_unrealize_common(s, errp);
 140 }
 141
 142 ssize_t virtio_pdu_vmarshal(V9fsPDU *pdu, size_t offset,
 143                             const char *fmt, va_list ap)
 144 {
 145     V9fsState *s = pdu->s;
 146     V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
 147     VirtQueueElement *elem = v->elems[pdu->idx];
 148
 149     return v9fs_iov_vmarshal(elem->in_sg, elem->in_num, offset, 1, fmt, ap);
 150 }
 151
 152 ssize_t virtio_pdu_vunmarshal(V9fsPDU *pdu, size_t offset,
 153                               const char *fmt, va_list ap)
 154 {
 155     V9fsState *s = pdu->s;
 156     V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
 157     VirtQueueElement *elem = v->elems[pdu->idx];
 158
 159     return v9fs_iov_vunmarshal(elem->out_sg, elem->out_num, offset, 1, fmt, ap);
 160 }
 161
 162 void virtio_init_iov_from_pdu(V9fsPDU *pdu, struct iovec **piov,
 163                               unsigned int *pniov, bool is_write)
 164 {
 165     V9fsState *s = pdu->s;
 166     V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
 167     VirtQueueElement *elem = v->elems[pdu->idx];
 168
 169     if (is_write) {
 170         *piov = elem->out_sg;
 171         *pniov = elem->out_num;
 172     } else {
 173         *piov = elem->in_sg;
 174         *pniov = elem->in_num;
 175     }
 176 }
 177
 178 /* virtio-9p device */
 179
 180 static Property virtio_9p_properties[] = {
 181     DEFINE_PROP_STRING("mount_tag", V9fsVirtioState, state.fsconf.tag),
 182     DEFINE_PROP_STRING("fsdev", V9fsVirtioState, state.fsconf.fsdev_id),
 183     DEFINE_PROP_END_OF_LIST(),
 184 };
 185
 186 static void virtio_9p_class_init(ObjectClass *klass, void *data)
 187 {
 188     DeviceClass *dc = DEVICE_CLASS(klass);
 189     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 190
 191     dc->props = virtio_9p_properties;
 192     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 193     vdc->realize = virtio_9p_device_realize;
 194     vdc->unrealize = virtio_9p_device_unrealize;
 195     vdc->get_features = virtio_9p_get_features;
 196     vdc->get_config = virtio_9p_get_config;
 197 }
 198
 199 static const TypeInfo virtio_device_info = {
 200     .name = TYPE_VIRTIO_9P,
 201     .parent = TYPE_VIRTIO_DEVICE,
 202     .instance_size = sizeof(V9fsVirtioState),
 203     .class_init = virtio_9p_class_init,
 204 };
 205
 206 static void virtio_9p_register_types(void)
 207 {
 208     type_register_static(&virtio_device_info);
 209 }
 210
 211 type_init(virtio_9p_register_types)