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) 209