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) 210