arch/um/drivers/virtio_uml.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Virtio vhost-user driver
   4  *
   5  * Copyright(c) 2019 Intel Corporation
   6  *
   7  * This driver allows virtio devices to be used over a vhost-user socket.
   8  *
   9  * Guest devices can be instantiated by kernel module or command line
  10  * parameters. One device will be created for each parameter. Syntax:
  11  *
  12  *              virtio_uml.device=<socket>:<virtio_id>[:<platform_id>]
  13  * where:
  14  *              <socket>        := vhost-user socket path to connect
  15  *              <virtio_id>     := virtio device id (as in virtio_ids.h)
  16  *              <platform_id>   := (optional) platform device id
  17  *
  18  * example:
  19  *              virtio_uml.device=/var/uml.socket:1
  20  *
  21  * Based on Virtio MMIO driver by Pawel Moll, copyright 2011-2014, ARM Ltd.
  22  */
  23 #include <linux/module.h>
  24 #include <linux/of.h>
  25 #include <linux/platform_device.h>
  26 #include <linux/slab.h>
  27 #include <linux/virtio.h>
  28 #include <linux/virtio_config.h>
  29 #include <linux/virtio_ring.h>
  30 #include <linux/time-internal.h>
  31 #include <linux/virtio-uml.h>
  32 #include <shared/as-layout.h>
  33 #include <irq_kern.h>
  34 #include <init.h>
  35 #include <os.h>
  36 #include "vhost_user.h"
  37
  38 #define MAX_SUPPORTED_QUEUE_SIZE        256
  39
  40 #define to_virtio_uml_device(_vdev) \
  41         container_of(_vdev, struct virtio_uml_device, vdev)
  42
  43 struct virtio_uml_platform_data {
  44         u32 virtio_device_id;
  45         const char *socket_path;
  46         struct work_struct conn_broken_wk;
  47         struct platform_device *pdev;
  48 };
  49
  50 struct virtio_uml_device {
  51         struct virtio_device vdev;
  52         struct platform_device *pdev;
  53         struct virtio_uml_platform_data *pdata;
  54
  55         spinlock_t sock_lock;
  56         int sock, req_fd, irq;
  57         u64 features;
  58         u64 protocol_features;
  59         u8 status;
  60         u8 registered:1;
  61         u8 suspended:1;
  62         u8 no_vq_suspend:1;
  63
  64         u8 config_changed_irq:1;
  65         uint64_t vq_irq_vq_map;
  66         int recv_rc;
  67 };
  68
  69 struct virtio_uml_vq_info {
  70         int kick_fd, call_fd;
  71         char name[32];
  72         bool suspended;
  73 };
  74
  75 extern unsigned long long physmem_size, highmem;
  76
  77 #define vu_err(vu_dev, ...)     dev_err(&(vu_dev)->pdev->dev, ##__VA_ARGS__)
  78
  79 /* Vhost-user protocol */
  80
  81 static int full_sendmsg_fds(int fd, const void *buf, unsigned int len,
  82                             const int *fds, unsigned int fds_num)
  83 {
  84         int rc;
  85
  86         do {
  87                 rc = os_sendmsg_fds(fd, buf, len, fds, fds_num);
  88                 if (rc > 0) {
  89                         buf += rc;
  90                         len -= rc;
  91                         fds = NULL;
  92                         fds_num = 0;
  93                 }
  94         } while (len && (rc >= 0 || rc == -EINTR));
  95
  96         if (rc < 0)
  97                 return rc;
  98         return 0;
  99 }
 100
 101 static int full_read(int fd, void *buf, int len, bool abortable)
 102 {
 103         int rc;
 104
 105         if (!len)
 106                 return 0;
 107
 108         do {
 109                 rc = os_read_file(fd, buf, len);
 110                 if (rc > 0) {
 111                         buf += rc;
 112                         len -= rc;
 113                 }
 114         } while (len && (rc > 0 || rc == -EINTR || (!abortable && rc == -EAGAIN)));
 115
 116         if (rc < 0)
 117                 return rc;
 118         if (rc == 0)
 119                 return -ECONNRESET;
 120         return 0;
 121 }
 122
 123 static int vhost_user_recv_header(int fd, struct vhost_user_msg *msg)
 124 {
 125         return full_read(fd, msg, sizeof(msg->header), true);
 126 }
 127
 128 static int vhost_user_recv(struct virtio_uml_device *vu_dev,
 129                            int fd, struct vhost_user_msg *msg,
 130                            size_t max_payload_size, bool wait)
 131 {
 132         size_t size;
 133         int rc;
 134
 135         /*
 136          * In virtio time-travel mode, we're handling all the vhost-user
 137          * FDs by polling them whenever appropriate. However, we may get
 138          * into a situation where we're sending out an interrupt message
 139          * to a device (e.g. a net device) and need to handle a simulation
 140          * time message while doing so, e.g. one that tells us to update
 141          * our idea of how long we can run without scheduling.
 142          *
 143          * Thus, we need to not just read() from the given fd, but need
 144          * to also handle messages for the simulation time - this function
 145          * does that for us while waiting for the given fd to be readable.
 146          */
 147         if (wait)
 148                 time_travel_wait_readable(fd);
 149
 150         rc = vhost_user_recv_header(fd, msg);
 151
 152         if (rc)
 153                 return rc;
 154         size = msg->header.size;
 155         if (size > max_payload_size)
 156                 return -EPROTO;
 157         return full_read(fd, &msg->payload, size, false);
 158 }
 159
 160 static void vhost_user_check_reset(struct virtio_uml_device *vu_dev,
 161                                    int rc)
 162 {
 163         struct virtio_uml_platform_data *pdata = vu_dev->pdata;
 164
 165         if (rc != -ECONNRESET)
 166                 return;
 167
 168         if (!vu_dev->registered)
 169                 return;
 170
 171         virtio_break_device(&vu_dev->vdev);
 172         schedule_work(&pdata->conn_broken_wk);
 173 }
 174
 175 static int vhost_user_recv_resp(struct virtio_uml_device *vu_dev,
 176                                 struct vhost_user_msg *msg,
 177                                 size_t max_payload_size)
 178 {
 179         int rc = vhost_user_recv(vu_dev, vu_dev->sock, msg,
 180                                  max_payload_size, true);
 181
 182         if (rc) {
 183                 vhost_user_check_reset(vu_dev, rc);
 184                 return rc;
 185         }
 186
 187         if (msg->header.flags != (VHOST_USER_FLAG_REPLY | VHOST_USER_VERSION))
 188                 return -EPROTO;
 189
 190         return 0;
 191 }
 192
 193 static int vhost_user_recv_u64(struct virtio_uml_device *vu_dev,
 194                                u64 *value)
 195 {
 196         struct vhost_user_msg msg;
 197         int rc = vhost_user_recv_resp(vu_dev, &msg,
 198                                       sizeof(msg.payload.integer));
 199
 200         if (rc)
 201                 return rc;
 202         if (msg.header.size != sizeof(msg.payload.integer))
 203                 return -EPROTO;
 204         *value = msg.payload.integer;
 205         return 0;
 206 }
 207
 208 static int vhost_user_recv_req(struct virtio_uml_device *vu_dev,
 209                                struct vhost_user_msg *msg,
 210                                size_t max_payload_size)
 211 {
 212         int rc = vhost_user_recv(vu_dev, vu_dev->req_fd, msg,
 213                                  max_payload_size, false);
 214
 215         if (rc)
 216                 return rc;
 217
 218         if ((msg->header.flags & ~VHOST_USER_FLAG_NEED_REPLY) !=
 219                         VHOST_USER_VERSION)
 220                 return -EPROTO;
 221
 222         return 0;
 223 }
 224
 225 static int vhost_user_send(struct virtio_uml_device *vu_dev,
 226                            bool need_response, struct vhost_user_msg *msg,
 227                            int *fds, size_t num_fds)
 228 {
 229         size_t size = sizeof(msg->header) + msg->header.size;
 230         unsigned long flags;
 231         bool request_ack;
 232         int rc;
 233
 234         msg->header.flags |= VHOST_USER_VERSION;
 235
 236         /*
 237          * The need_response flag indicates that we already need a response,
 238          * e.g. to read the features. In these cases, don't request an ACK as
 239          * it is meaningless. Also request an ACK only if supported.
 240          */
 241         request_ack = !need_response;
 242         if (!(vu_dev->protocol_features &
 243                         BIT_ULL(VHOST_USER_PROTOCOL_F_REPLY_ACK)))
 244                 request_ack = false;
 245
 246         if (request_ack)
 247                 msg->header.flags |= VHOST_USER_FLAG_NEED_REPLY;
 248
 249         spin_lock_irqsave(&vu_dev->sock_lock, flags);
 250         rc = full_sendmsg_fds(vu_dev->sock, msg, size, fds, num_fds);
 251         if (rc < 0)
 252                 goto out;
 253
 254         if (request_ack) {
 255                 uint64_t status;
 256
 257                 rc = vhost_user_recv_u64(vu_dev, &status);
 258                 if (rc)
 259                         goto out;
 260
 261                 if (status) {
 262                         vu_err(vu_dev, "slave reports error: %llu\n", status);
 263                         rc = -EIO;
 264                         goto out;
 265                 }
 266         }
 267
 268 out:
 269         spin_unlock_irqrestore(&vu_dev->sock_lock, flags);
 270         return rc;
 271 }
 272
 273 static int vhost_user_send_no_payload(struct virtio_uml_device *vu_dev,
 274                                       bool need_response, u32 request)
 275 {
 276         struct vhost_user_msg msg = {
 277                 .header.request = request,
 278         };
 279
 280         return vhost_user_send(vu_dev, need_response, &msg, NULL, 0);
 281 }
 282
 283 static int vhost_user_send_no_payload_fd(struct virtio_uml_device *vu_dev,
 284                                          u32 request, int fd)
 285 {
 286         struct vhost_user_msg msg = {
 287                 .header.request = request,
 288         };
 289
 290         return vhost_user_send(vu_dev, false, &msg, &fd, 1);
 291 }
 292
 293 static int vhost_user_send_u64(struct virtio_uml_device *vu_dev,
 294                                u32 request, u64 value)
 295 {
 296         struct vhost_user_msg msg = {
 297                 .header.request = request,
 298                 .header.size = sizeof(msg.payload.integer),
 299                 .payload.integer = value,
 300         };
 301
 302         return vhost_user_send(vu_dev, false, &msg, NULL, 0);
 303 }
 304
 305 static int vhost_user_set_owner(struct virtio_uml_device *vu_dev)
 306 {
 307         return vhost_user_send_no_payload(vu_dev, false, VHOST_USER_SET_OWNER);
 308 }
 309
 310 static int vhost_user_get_features(struct virtio_uml_device *vu_dev,
 311                                    u64 *features)
 312 {
 313         int rc = vhost_user_send_no_payload(vu_dev, true,
 314                                             VHOST_USER_GET_FEATURES);
 315
 316         if (rc)
 317                 return rc;
 318         return vhost_user_recv_u64(vu_dev, features);
 319 }
 320
 321 static int vhost_user_set_features(struct virtio_uml_device *vu_dev,
 322                                    u64 features)
 323 {
 324         return vhost_user_send_u64(vu_dev, VHOST_USER_SET_FEATURES, features);
 325 }
 326
 327 static int vhost_user_get_protocol_features(struct virtio_uml_device *vu_dev,
 328                                             u64 *protocol_features)
 329 {
 330         int rc = vhost_user_send_no_payload(vu_dev, true,
 331                         VHOST_USER_GET_PROTOCOL_FEATURES);
 332
 333         if (rc)
 334                 return rc;
 335         return vhost_user_recv_u64(vu_dev, protocol_features);
 336 }
 337
 338 static int vhost_user_set_protocol_features(struct virtio_uml_device *vu_dev,
 339                                             u64 protocol_features)
 340 {
 341         return vhost_user_send_u64(vu_dev, VHOST_USER_SET_PROTOCOL_FEATURES,
 342                                    protocol_features);
 343 }
 344
 345 static void vhost_user_reply(struct virtio_uml_device *vu_dev,
 346                              struct vhost_user_msg *msg, int response)
 347 {
 348         struct vhost_user_msg reply = {
 349                 .payload.integer = response,
 350         };
 351         size_t size = sizeof(reply.header) + sizeof(reply.payload.integer);
 352         int rc;
 353
 354         reply.header = msg->header;
 355         reply.header.flags &= ~VHOST_USER_FLAG_NEED_REPLY;
 356         reply.header.flags |= VHOST_USER_FLAG_REPLY;
 357         reply.header.size = sizeof(reply.payload.integer);
 358
 359         rc = full_sendmsg_fds(vu_dev->req_fd, &reply, size, NULL, 0);
 360
 361         if (rc)
 362                 vu_err(vu_dev,
 363                        "sending reply to slave request failed: %d (size %zu)\n",
 364                        rc, size);
 365 }
 366
 367 static irqreturn_t vu_req_read_message(struct virtio_uml_device *vu_dev,
 368                                        struct time_travel_event *ev)
 369 {
 370         struct virtqueue *vq;
 371         int response = 1;
 372         struct {
 373                 struct vhost_user_msg msg;
 374                 u8 extra_payload[512];
 375         } msg;
 376         int rc;
 377
 378         rc = vhost_user_recv_req(vu_dev, &msg.msg,
 379                                  sizeof(msg.msg.payload) +
 380                                  sizeof(msg.extra_payload));
 381
 382         vu_dev->recv_rc = rc;
 383         if (rc)
 384                 return IRQ_NONE;
 385
 386         switch (msg.msg.header.request) {
 387         case VHOST_USER_SLAVE_CONFIG_CHANGE_MSG:
 388                 vu_dev->config_changed_irq = true;
 389                 response = 0;
 390                 break;
 391         case VHOST_USER_SLAVE_VRING_CALL:
 392                 virtio_device_for_each_vq((&vu_dev->vdev), vq) {
 393                         if (vq->index == msg.msg.payload.vring_state.index) {
 394                                 response = 0;
 395                                 vu_dev->vq_irq_vq_map |= BIT_ULL(vq->index);
 396                                 break;
 397                         }
 398                 }
 399                 break;
 400         case VHOST_USER_SLAVE_IOTLB_MSG:
 401                 /* not supported - VIRTIO_F_ACCESS_PLATFORM */
 402         case VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG:
 403                 /* not supported - VHOST_USER_PROTOCOL_F_HOST_NOTIFIER */
 404         default:
 405                 vu_err(vu_dev, "unexpected slave request %d\n",
 406                        msg.msg.header.request);
 407         }
 408
 409         if (ev && !vu_dev->suspended)
 410                 time_travel_add_irq_event(ev);
 411
 412         if (msg.msg.header.flags & VHOST_USER_FLAG_NEED_REPLY)
 413                 vhost_user_reply(vu_dev, &msg.msg, response);
 414
 415         return IRQ_HANDLED;
 416 }
 417
 418 static irqreturn_t vu_req_interrupt(int irq, void *data)
 419 {
 420         struct virtio_uml_device *vu_dev = data;
 421         irqreturn_t ret = IRQ_HANDLED;
 422
 423         if (!um_irq_timetravel_handler_used())
 424                 ret = vu_req_read_message(vu_dev, NULL);
 425
 426         if (vu_dev->recv_rc) {
 427                 vhost_user_check_reset(vu_dev, vu_dev->recv_rc);
 428         } else if (vu_dev->vq_irq_vq_map) {
 429                 struct virtqueue *vq;
 430
 431                 virtio_device_for_each_vq((&vu_dev->vdev), vq) {
 432                         if (vu_dev->vq_irq_vq_map & BIT_ULL(vq->index))
 433                                 vring_interrupt(0 /* ignored */, vq);
 434                 }
 435                 vu_dev->vq_irq_vq_map = 0;
 436         } else if (vu_dev->config_changed_irq) {
 437                 virtio_config_changed(&vu_dev->vdev);
 438                 vu_dev->config_changed_irq = false;
 439         }
 440
 441         return ret;
 442 }
 443
 444 static void vu_req_interrupt_comm_handler(int irq, int fd, void *data,
 445                                           struct time_travel_event *ev)
 446 {
 447         vu_req_read_message(data, ev);
 448 }
 449
 450 static int vhost_user_init_slave_req(struct virtio_uml_device *vu_dev)
 451 {
 452         int rc, req_fds[2];
 453
 454         /* Use a pipe for slave req fd, SIGIO is not supported for eventfd */
 455         rc = os_pipe(req_fds, true, true);
 456         if (rc < 0)
 457                 return rc;
 458         vu_dev->req_fd = req_fds[0];
 459
 460         rc = um_request_irq_tt(UM_IRQ_ALLOC, vu_dev->req_fd, IRQ_READ,
 461                                vu_req_interrupt, IRQF_SHARED,
 462                                vu_dev->pdev->name, vu_dev,
 463                                vu_req_interrupt_comm_handler);
 464         if (rc < 0)
 465                 goto err_close;
 466
 467         vu_dev->irq = rc;
 468
 469         rc = vhost_user_send_no_payload_fd(vu_dev, VHOST_USER_SET_SLAVE_REQ_FD,
 470                                            req_fds[1]);
 471         if (rc)
 472                 goto err_free_irq;
 473
 474         goto out;
 475
 476 err_free_irq:
 477         um_free_irq(vu_dev->irq, vu_dev);
 478 err_close:
 479         os_close_file(req_fds[0]);
 480 out:
 481         /* Close unused write end of request fds */
 482         os_close_file(req_fds[1]);
 483         return rc;
 484 }
 485
 486 static int vhost_user_init(struct virtio_uml_device *vu_dev)
 487 {
 488         int rc = vhost_user_set_owner(vu_dev);
 489
 490         if (rc)
 491                 return rc;
 492         rc = vhost_user_get_features(vu_dev, &vu_dev->features);
 493         if (rc)
 494                 return rc;
 495
 496         if (vu_dev->features & BIT_ULL(VHOST_USER_F_PROTOCOL_FEATURES)) {
 497                 rc = vhost_user_get_protocol_features(vu_dev,
 498                                 &vu_dev->protocol_features);
 499                 if (rc)
 500                         return rc;
 501                 vu_dev->protocol_features &= VHOST_USER_SUPPORTED_PROTOCOL_F;
 502                 rc = vhost_user_set_protocol_features(vu_dev,
 503                                 vu_dev->protocol_features);
 504                 if (rc)
 505                         return rc;
 506         }
 507
 508         if (vu_dev->protocol_features &
 509                         BIT_ULL(VHOST_USER_PROTOCOL_F_SLAVE_REQ)) {
 510                 rc = vhost_user_init_slave_req(vu_dev);
 511                 if (rc)
 512                         return rc;
 513         }
 514
 515         return 0;
 516 }
 517
 518 static void vhost_user_get_config(struct virtio_uml_device *vu_dev,
 519                                   u32 offset, void *buf, u32 len)
 520 {
 521         u32 cfg_size = offset + len;
 522         struct vhost_user_msg *msg;
 523         size_t payload_size = sizeof(msg->payload.config) + cfg_size;
 524         size_t msg_size = sizeof(msg->header) + payload_size;
 525         int rc;
 526
 527         if (!(vu_dev->protocol_features &
 528               BIT_ULL(VHOST_USER_PROTOCOL_F_CONFIG)))
 529                 return;
 530
 531         msg = kzalloc(msg_size, GFP_KERNEL);
 532         if (!msg)
 533                 return;
 534         msg->header.request = VHOST_USER_GET_CONFIG;
 535         msg->header.size = payload_size;
 536         msg->payload.config.offset = 0;
 537         msg->payload.config.size = cfg_size;
 538
 539         rc = vhost_user_send(vu_dev, true, msg, NULL, 0);
 540         if (rc) {
 541                 vu_err(vu_dev, "sending VHOST_USER_GET_CONFIG failed: %d\n",
 542                        rc);
 543                 goto free;
 544         }
 545
 546         rc = vhost_user_recv_resp(vu_dev, msg, msg_size);
 547         if (rc) {
 548                 vu_err(vu_dev,
 549                        "receiving VHOST_USER_GET_CONFIG response failed: %d\n",
 550                        rc);
 551                 goto free;
 552         }
 553
 554         if (msg->header.size != payload_size ||
 555             msg->payload.config.size != cfg_size) {
 556                 rc = -EPROTO;
 557                 vu_err(vu_dev,
 558                        "Invalid VHOST_USER_GET_CONFIG sizes (payload %d expected %zu, config %u expected %u)\n",
 559                        msg->header.size, payload_size,
 560                        msg->payload.config.size, cfg_size);
 561                 goto free;
 562         }
 563         memcpy(buf, msg->payload.config.payload + offset, len);
 564
 565 free:
 566         kfree(msg);
 567 }
 568
 569 static void vhost_user_set_config(struct virtio_uml_device *vu_dev,
 570                                   u32 offset, const void *buf, u32 len)
 571 {
 572         struct vhost_user_msg *msg;
 573         size_t payload_size = sizeof(msg->payload.config) + len;
 574         size_t msg_size = sizeof(msg->header) + payload_size;
 575         int rc;
 576
 577         if (!(vu_dev->protocol_features &
 578               BIT_ULL(VHOST_USER_PROTOCOL_F_CONFIG)))
 579                 return;
 580
 581         msg = kzalloc(msg_size, GFP_KERNEL);
 582         if (!msg)
 583                 return;
 584         msg->header.request = VHOST_USER_SET_CONFIG;
 585         msg->header.size = payload_size;
 586         msg->payload.config.offset = offset;
 587         msg->payload.config.size = len;
 588         memcpy(msg->payload.config.payload, buf, len);
 589
 590         rc = vhost_user_send(vu_dev, false, msg, NULL, 0);
 591         if (rc)
 592                 vu_err(vu_dev, "sending VHOST_USER_SET_CONFIG failed: %d\n",
 593                        rc);
 594
 595         kfree(msg);
 596 }
 597
 598 static int vhost_user_init_mem_region(u64 addr, u64 size, int *fd_out,
 599                                       struct vhost_user_mem_region *region_out)
 600 {
 601         unsigned long long mem_offset;
 602         int rc = phys_mapping(addr, &mem_offset);
 603
 604         if (WARN(rc < 0, "phys_mapping of 0x%llx returned %d\n", addr, rc))
 605                 return -EFAULT;
 606         *fd_out = rc;
 607         region_out->guest_addr = addr;
 608         region_out->user_addr = addr;
 609         region_out->size = size;
 610         region_out->mmap_offset = mem_offset;
 611
 612         /* Ensure mapping is valid for the entire region */
 613         rc = phys_mapping(addr + size - 1, &mem_offset);
 614         if (WARN(rc != *fd_out, "phys_mapping of 0x%llx failed: %d != %d\n",
 615                  addr + size - 1, rc, *fd_out))
 616                 return -EFAULT;
 617         return 0;
 618 }
 619
 620 static int vhost_user_set_mem_table(struct virtio_uml_device *vu_dev)
 621 {
 622         struct vhost_user_msg msg = {
 623                 .header.request = VHOST_USER_SET_MEM_TABLE,
 624                 .header.size = sizeof(msg.payload.mem_regions),
 625                 .payload.mem_regions.num = 1,
 626         };
 627         unsigned long reserved = uml_reserved - uml_physmem;
 628         int fds[2];
 629         int rc;
 630
 631         /*
 632          * This is a bit tricky, see also the comment with setup_physmem().
 633          *
 634          * Essentially, setup_physmem() uses a file to mmap() our physmem,
 635          * but the code and data we *already* have is omitted. To us, this
 636          * is no difference, since they both become part of our address
 637          * space and memory consumption. To somebody looking in from the
 638          * outside, however, it is different because the part of our memory
 639          * consumption that's already part of the binary (code/data) is not
 640          * mapped from the file, so it's not visible to another mmap from
 641          * the file descriptor.
 642          *
 643          * Thus, don't advertise this space to the vhost-user slave. This
 644          * means that the slave will likely abort or similar when we give
 645          * it an address from the hidden range, since it's not marked as
 646          * a valid address, but at least that way we detect the issue and
 647          * don't just have the slave read an all-zeroes buffer from the
 648          * shared memory file, or write something there that we can never
 649          * see (depending on the direction of the virtqueue traffic.)
 650          *
 651          * Since we usually don't want to use .text for virtio buffers,
 652          * this effectively means that you cannot use
 653          *  1) global variables, which are in the .bss and not in the shm
 654          *     file-backed memory
 655          *  2) the stack in some processes, depending on where they have
 656          *     their stack (or maybe only no interrupt stack?)
 657          *
 658          * The stack is already not typically valid for DMA, so this isn't
 659          * much of a restriction, but global variables might be encountered.
 660          *
 661          * It might be possible to fix it by copying around the data that's
 662          * between bss_start and where we map the file now, but it's not
 663          * something that you typically encounter with virtio drivers, so
 664          * it didn't seem worthwhile.
 665          */
 666         rc = vhost_user_init_mem_region(reserved, physmem_size - reserved,
 667                                         &fds[0],
 668                                         &msg.payload.mem_regions.regions[0]);
 669
 670         if (rc < 0)
 671                 return rc;
 672         if (highmem) {
 673                 msg.payload.mem_regions.num++;
 674                 rc = vhost_user_init_mem_region(__pa(end_iomem), highmem,
 675                                 &fds[1], &msg.payload.mem_regions.regions[1]);
 676                 if (rc < 0)
 677                         return rc;
 678         }
 679
 680         return vhost_user_send(vu_dev, false, &msg, fds,
 681                                msg.payload.mem_regions.num);
 682 }
 683
 684 static int vhost_user_set_vring_state(struct virtio_uml_device *vu_dev,
 685                                       u32 request, u32 index, u32 num)
 686 {
 687         struct vhost_user_msg msg = {
 688                 .header.request = request,
 689                 .header.size = sizeof(msg.payload.vring_state),
 690                 .payload.vring_state.index = index,
 691                 .payload.vring_state.num = num,
 692         };
 693
 694         return vhost_user_send(vu_dev, false, &msg, NULL, 0);
 695 }
 696
 697 static int vhost_user_set_vring_num(struct virtio_uml_device *vu_dev,
 698                                     u32 index, u32 num)
 699 {
 700         return vhost_user_set_vring_state(vu_dev, VHOST_USER_SET_VRING_NUM,
 701                                           index, num);
 702 }
 703
 704 static int vhost_user_set_vring_base(struct virtio_uml_device *vu_dev,
 705                                      u32 index, u32 offset)
 706 {
 707         return vhost_user_set_vring_state(vu_dev, VHOST_USER_SET_VRING_BASE,
 708                                           index, offset);
 709 }
 710
 711 static int vhost_user_set_vring_addr(struct virtio_uml_device *vu_dev,
 712                                      u32 index, u64 desc, u64 used, u64 avail,
 713                                      u64 log)
 714 {
 715         struct vhost_user_msg msg = {
 716                 .header.request = VHOST_USER_SET_VRING_ADDR,
 717                 .header.size = sizeof(msg.payload.vring_addr),
 718                 .payload.vring_addr.index = index,
 719                 .payload.vring_addr.desc = desc,
 720                 .payload.vring_addr.used = used,
 721                 .payload.vring_addr.avail = avail,
 722                 .payload.vring_addr.log = log,
 723         };
 724
 725         return vhost_user_send(vu_dev, false, &msg, NULL, 0);
 726 }
 727
 728 static int vhost_user_set_vring_fd(struct virtio_uml_device *vu_dev,
 729                                    u32 request, int index, int fd)
 730 {
 731         struct vhost_user_msg msg = {
 732                 .header.request = request,
 733                 .header.size = sizeof(msg.payload.integer),
 734                 .payload.integer = index,
 735         };
 736
 737         if (index & ~VHOST_USER_VRING_INDEX_MASK)
 738                 return -EINVAL;
 739         if (fd < 0) {
 740                 msg.payload.integer |= VHOST_USER_VRING_POLL_MASK;
 741                 return vhost_user_send(vu_dev, false, &msg, NULL, 0);
 742         }
 743         return vhost_user_send(vu_dev, false, &msg, &fd, 1);
 744 }
 745
 746 static int vhost_user_set_vring_call(struct virtio_uml_device *vu_dev,
 747                                      int index, int fd)
 748 {
 749         return vhost_user_set_vring_fd(vu_dev, VHOST_USER_SET_VRING_CALL,
 750                                        index, fd);
 751 }
 752
 753 static int vhost_user_set_vring_kick(struct virtio_uml_device *vu_dev,
 754                                      int index, int fd)
 755 {
 756         return vhost_user_set_vring_fd(vu_dev, VHOST_USER_SET_VRING_KICK,
 757                                        index, fd);
 758 }
 759
 760 static int vhost_user_set_vring_enable(struct virtio_uml_device *vu_dev,
 761                                        u32 index, bool enable)
 762 {
 763         if (!(vu_dev->features & BIT_ULL(VHOST_USER_F_PROTOCOL_FEATURES)))
 764                 return 0;
 765
 766         return vhost_user_set_vring_state(vu_dev, VHOST_USER_SET_VRING_ENABLE,
 767                                           index, enable);
 768 }
 769
 770
 771 /* Virtio interface */
 772
 773 static bool vu_notify(struct virtqueue *vq)
 774 {
 775         struct virtio_uml_vq_info *info = vq->priv;
 776         const uint64_t n = 1;
 777         int rc;
 778
 779         if (info->suspended)
 780                 return true;
 781
 782         time_travel_propagate_time();
 783
 784         if (info->kick_fd < 0) {
 785                 struct virtio_uml_device *vu_dev;
 786
 787                 vu_dev = to_virtio_uml_device(vq->vdev);
 788
 789                 return vhost_user_set_vring_state(vu_dev, VHOST_USER_VRING_KICK,
 790                                                   vq->index, 0) == 0;
 791         }
 792
 793         do {
 794                 rc = os_write_file(info->kick_fd, &n, sizeof(n));
 795         } while (rc == -EINTR);
 796         return !WARN(rc != sizeof(n), "write returned %d\n", rc);
 797 }
 798
 799 static irqreturn_t vu_interrupt(int irq, void *opaque)
 800 {
 801         struct virtqueue *vq = opaque;
 802         struct virtio_uml_vq_info *info = vq->priv;
 803         uint64_t n;
 804         int rc;
 805         irqreturn_t ret = IRQ_NONE;
 806
 807         do {
 808                 rc = os_read_file(info->call_fd, &n, sizeof(n));
 809                 if (rc == sizeof(n))
 810                         ret |= vring_interrupt(irq, vq);
 811         } while (rc == sizeof(n) || rc == -EINTR);
 812         WARN(rc != -EAGAIN, "read returned %d\n", rc);
 813         return ret;
 814 }
 815
 816
 817 static void vu_get(struct virtio_device *vdev, unsigned offset,
 818                    void *buf, unsigned len)
 819 {
 820         struct virtio_uml_device *vu_dev = to_virtio_uml_device(vdev);
 821
 822         vhost_user_get_config(vu_dev, offset, buf, len);
 823 }
 824
 825 static void vu_set(struct virtio_device *vdev, unsigned offset,
 826                    const void *buf, unsigned len)
 827 {
 828         struct virtio_uml_device *vu_dev = to_virtio_uml_device(vdev);
 829
 830         vhost_user_set_config(vu_dev, offset, buf, len);
 831 }
 832
 833 static u8 vu_get_status(struct virtio_device *vdev)
 834 {
 835         struct virtio_uml_device *vu_dev = to_virtio_uml_device(vdev);
 836
 837         return vu_dev->status;
 838 }
 839
 840 static void vu_set_status(struct virtio_device *vdev, u8 status)
 841 {
 842         struct virtio_uml_device *vu_dev = to_virtio_uml_device(vdev);
 843
 844         vu_dev->status = status;
 845 }
 846
 847 static void vu_reset(struct virtio_device *vdev)
 848 {
 849         struct virtio_uml_device *vu_dev = to_virtio_uml_device(vdev);
 850
 851         vu_dev->status = 0;
 852 }
 853
 854 static void vu_del_vq(struct virtqueue *vq)
 855 {
 856         struct virtio_uml_vq_info *info = vq->priv;
 857
 858         if (info->call_fd >= 0) {
 859                 struct virtio_uml_device *vu_dev;
 860
 861                 vu_dev = to_virtio_uml_device(vq->vdev);
 862
 863                 um_free_irq(vu_dev->irq, vq);
 864                 os_close_file(info->call_fd);
 865         }
 866
 867         if (info->kick_fd >= 0)
 868                 os_close_file(info->kick_fd);
 869
 870         vring_del_virtqueue(vq);
 871         kfree(info);
 872 }
 873
 874 static void vu_del_vqs(struct virtio_device *vdev)
 875 {
 876         struct virtio_uml_device *vu_dev = to_virtio_uml_device(vdev);
 877         struct virtqueue *vq, *n;
 878         u64 features;
 879
 880         /* Note: reverse order as a workaround to a decoding bug in snabb */
 881         list_for_each_entry_reverse(vq, &vdev->vqs, list)
 882                 WARN_ON(vhost_user_set_vring_enable(vu_dev, vq->index, false));
 883
 884         /* Ensure previous messages have been processed */
 885         WARN_ON(vhost_user_get_features(vu_dev, &features));
 886
 887         list_for_each_entry_safe(vq, n, &vdev->vqs, list)
 888                 vu_del_vq(vq);
 889 }
 890
 891 static int vu_setup_vq_call_fd(struct virtio_uml_device *vu_dev,
 892                                struct virtqueue *vq)
 893 {
 894         struct virtio_uml_vq_info *info = vq->priv;
 895         int call_fds[2];
 896         int rc;
 897
 898         /* no call FD needed/desired in this case */
 899         if (vu_dev->protocol_features &
 900                         BIT_ULL(VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS) &&
 901             vu_dev->protocol_features &
 902                         BIT_ULL(VHOST_USER_PROTOCOL_F_SLAVE_REQ)) {
 903                 info->call_fd = -1;
 904                 return 0;
 905         }
 906
 907         /* Use a pipe for call fd, since SIGIO is not supported for eventfd */
 908         rc = os_pipe(call_fds, true, true);
 909         if (rc < 0)
 910                 return rc;
 911
 912         info->call_fd = call_fds[0];
 913         rc = um_request_irq(vu_dev->irq, info->call_fd, IRQ_READ,
 914                             vu_interrupt, IRQF_SHARED, info->name, vq);
 915         if (rc < 0)
 916                 goto close_both;
 917
 918         rc = vhost_user_set_vring_call(vu_dev, vq->index, call_fds[1]);
 919         if (rc)
 920                 goto release_irq;
 921
 922         goto out;
 923
 924 release_irq:
 925         um_free_irq(vu_dev->irq, vq);
 926 close_both:
 927         os_close_file(call_fds[0]);
 928 out:
 929         /* Close (unused) write end of call fds */
 930         os_close_file(call_fds[1]);
 931
 932         return rc;
 933 }
 934
 935 static struct virtqueue *vu_setup_vq(struct virtio_device *vdev,
 936                                      unsigned index, vq_callback_t *callback,
 937                                      const char *name, bool ctx)
 938 {
 939         struct virtio_uml_device *vu_dev = to_virtio_uml_device(vdev);
 940         struct platform_device *pdev = vu_dev->pdev;
 941         struct virtio_uml_vq_info *info;
 942         struct virtqueue *vq;
 943         int num = MAX_SUPPORTED_QUEUE_SIZE;
 944         int rc;
 945
 946         info = kzalloc(sizeof(*info), GFP_KERNEL);
 947         if (!info) {
 948                 rc = -ENOMEM;
 949                 goto error_kzalloc;
 950         }
 951         snprintf(info->name, sizeof(info->name), "%s.%d-%s", pdev->name,
 952                  pdev->id, name);
 953
 954         vq = vring_create_virtqueue(index, num, PAGE_SIZE, vdev, true, true,
 955                                     ctx, vu_notify, callback, info->name);
 956         if (!vq) {
 957                 rc = -ENOMEM;
 958                 goto error_create;
 959         }
 960         vq->priv = info;
 961         vq->num_max = num;
 962         num = virtqueue_get_vring_size(vq);
 963
 964         if (vu_dev->protocol_features &
 965                         BIT_ULL(VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS)) {
 966                 info->kick_fd = -1;
 967         } else {
 968                 rc = os_eventfd(0, 0);
 969                 if (rc < 0)
 970                         goto error_kick;
 971                 info->kick_fd = rc;
 972         }
 973
 974         rc = vu_setup_vq_call_fd(vu_dev, vq);
 975         if (rc)
 976                 goto error_call;
 977
 978         rc = vhost_user_set_vring_num(vu_dev, index, num);
 979         if (rc)
 980                 goto error_setup;
 981
 982         rc = vhost_user_set_vring_base(vu_dev, index, 0);
 983         if (rc)
 984                 goto error_setup;
 985
 986         rc = vhost_user_set_vring_addr(vu_dev, index,
 987                                        virtqueue_get_desc_addr(vq),
 988                                        virtqueue_get_used_addr(vq),
 989                                        virtqueue_get_avail_addr(vq),
 990                                        (u64) -1);
 991         if (rc)
 992                 goto error_setup;
 993
 994         return vq;
 995
 996 error_setup:
 997         if (info->call_fd >= 0) {
 998                 um_free_irq(vu_dev->irq, vq);
 999                 os_close_file(info->call_fd);
1000         }
1001 error_call:
1002         if (info->kick_fd >= 0)
1003                 os_close_file(info->kick_fd);
1004 error_kick:
1005         vring_del_virtqueue(vq);
1006 error_create:
1007         kfree(info);
1008 error_kzalloc:
1009         return ERR_PTR(rc);
1010 }
1011
1012 static int vu_find_vqs(struct virtio_device *vdev, unsigned nvqs,
1013                        struct virtqueue *vqs[], vq_callback_t *callbacks[],
1014                        const char * const names[], u32 sizes[], const bool *ctx,
1015                        struct irq_affinity *desc)
1016 {
1017         struct virtio_uml_device *vu_dev = to_virtio_uml_device(vdev);
1018         int i, queue_idx = 0, rc;
1019         struct virtqueue *vq;
1020
1021         /* not supported for now */
1022         if (WARN_ON(nvqs > 64))
1023                 return -EINVAL;
1024
1025         rc = vhost_user_set_mem_table(vu_dev);
1026         if (rc)
1027                 return rc;
1028
1029         for (i = 0; i < nvqs; ++i) {
1030                 if (!names[i]) {
1031                         vqs[i] = NULL;
1032                         continue;
1033                 }
1034
1035                 vqs[i] = vu_setup_vq(vdev, queue_idx++, callbacks[i], names[i],
1036                                      ctx ? ctx[i] : false);
1037                 if (IS_ERR(vqs[i])) {
1038                         rc = PTR_ERR(vqs[i]);
1039                         goto error_setup;
1040                 }
1041         }
1042
1043         list_for_each_entry(vq, &vdev->vqs, list) {
1044                 struct virtio_uml_vq_info *info = vq->priv;
1045
1046                 if (info->kick_fd >= 0) {
1047                         rc = vhost_user_set_vring_kick(vu_dev, vq->index,
1048                                                        info->kick_fd);
1049                         if (rc)
1050                                 goto error_setup;
1051                 }
1052
1053                 rc = vhost_user_set_vring_enable(vu_dev, vq->index, true);
1054                 if (rc)
1055                         goto error_setup;
1056         }
1057
1058         return 0;
1059
1060 error_setup:
1061         vu_del_vqs(vdev);
1062         return rc;
1063 }
1064
1065 static u64 vu_get_features(struct virtio_device *vdev)
1066 {
1067         struct virtio_uml_device *vu_dev = to_virtio_uml_device(vdev);
1068
1069         return vu_dev->features;
1070 }
1071
1072 static int vu_finalize_features(struct virtio_device *vdev)
1073 {
1074         struct virtio_uml_device *vu_dev = to_virtio_uml_device(vdev);
1075         u64 supported = vdev->features & VHOST_USER_SUPPORTED_F;
1076
1077         vring_transport_features(vdev);
1078         vu_dev->features = vdev->features | supported;
1079
1080         return vhost_user_set_features(vu_dev, vu_dev->features);
1081 }
1082
1083 static const char *vu_bus_name(struct virtio_device *vdev)
1084 {
1085         struct virtio_uml_device *vu_dev = to_virtio_uml_device(vdev);
1086
1087         return vu_dev->pdev->name;
1088 }
1089
1090 static const struct virtio_config_ops virtio_uml_config_ops = {
1091         .get = vu_get,
1092         .set = vu_set,
1093         .get_status = vu_get_status,
1094         .set_status = vu_set_status,
1095         .reset = vu_reset,
1096         .find_vqs = vu_find_vqs,
1097         .del_vqs = vu_del_vqs,
1098         .get_features = vu_get_features,
1099         .finalize_features = vu_finalize_features,
1100         .bus_name = vu_bus_name,
1101 };
1102
1103 static void virtio_uml_release_dev(struct device *d)
1104 {
1105         struct virtio_device *vdev =
1106                         container_of(d, struct virtio_device, dev);
1107         struct virtio_uml_device *vu_dev = to_virtio_uml_device(vdev);
1108
1109         time_travel_propagate_time();
1110
1111         /* might not have been opened due to not negotiating the feature */
1112         if (vu_dev->req_fd >= 0) {
1113                 um_free_irq(vu_dev->irq, vu_dev);
1114                 os_close_file(vu_dev->req_fd);
1115         }
1116
1117         os_close_file(vu_dev->sock);
1118         kfree(vu_dev);
1119 }
1120
1121 void virtio_uml_set_no_vq_suspend(struct virtio_device *vdev,
1122                                   bool no_vq_suspend)
1123 {
1124         struct virtio_uml_device *vu_dev = to_virtio_uml_device(vdev);
1125
1126         if (WARN_ON(vdev->config != &virtio_uml_config_ops))
1127                 return;
1128
1129         vu_dev->no_vq_suspend = no_vq_suspend;
1130         dev_info(&vdev->dev, "%sabled VQ suspend\n",
1131                  no_vq_suspend ? "dis" : "en");
1132 }
1133
1134 static void vu_of_conn_broken(struct work_struct *wk)
1135 {
1136         /*
1137          * We can't remove the device from the devicetree so the only thing we
1138          * can do is warn.
1139          */
1140         WARN_ON(1);
1141 }
1142
1143 /* Platform device */
1144
1145 static struct virtio_uml_platform_data *
1146 virtio_uml_create_pdata(struct platform_device *pdev)
1147 {
1148         struct device_node *np = pdev->dev.of_node;
1149         struct virtio_uml_platform_data *pdata;
1150         int ret;
1151
1152         if (!np)
1153                 return ERR_PTR(-EINVAL);
1154
1155         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
1156         if (!pdata)
1157                 return ERR_PTR(-ENOMEM);
1158
1159         INIT_WORK(&pdata->conn_broken_wk, vu_of_conn_broken);
1160         pdata->pdev = pdev;
1161
1162         ret = of_property_read_string(np, "socket-path", &pdata->socket_path);
1163         if (ret)
1164                 return ERR_PTR(ret);
1165
1166         ret = of_property_read_u32(np, "virtio-device-id",
1167                                    &pdata->virtio_device_id);
1168         if (ret)
1169                 return ERR_PTR(ret);
1170
1171         return pdata;
1172 }
1173
1174 static int virtio_uml_probe(struct platform_device *pdev)
1175 {
1176         struct virtio_uml_platform_data *pdata = pdev->dev.platform_data;
1177         struct virtio_uml_device *vu_dev;
1178         int rc;
1179
1180         if (!pdata) {
1181                 pdata = virtio_uml_create_pdata(pdev);
1182                 if (IS_ERR(pdata))
1183                         return PTR_ERR(pdata);
1184         }
1185
1186         vu_dev = kzalloc(sizeof(*vu_dev), GFP_KERNEL);
1187         if (!vu_dev)
1188                 return -ENOMEM;
1189
1190         vu_dev->pdata = pdata;
1191         vu_dev->vdev.dev.parent = &pdev->dev;
1192         vu_dev->vdev.dev.release = virtio_uml_release_dev;
1193         vu_dev->vdev.config = &virtio_uml_config_ops;
1194         vu_dev->vdev.id.device = pdata->virtio_device_id;
1195         vu_dev->vdev.id.vendor = VIRTIO_DEV_ANY_ID;
1196         vu_dev->pdev = pdev;
1197         vu_dev->req_fd = -1;
1198
1199         time_travel_propagate_time();
1200
1201         do {
1202                 rc = os_connect_socket(pdata->socket_path);
1203         } while (rc == -EINTR);
1204         if (rc < 0)
1205                 goto error_free;
1206         vu_dev->sock = rc;
1207
1208         spin_lock_init(&vu_dev->sock_lock);
1209
1210         rc = vhost_user_init(vu_dev);
1211         if (rc)
1212                 goto error_init;
1213
1214         platform_set_drvdata(pdev, vu_dev);
1215
1216         device_set_wakeup_capable(&vu_dev->vdev.dev, true);
1217
1218         rc = register_virtio_device(&vu_dev->vdev);
1219         if (rc)
1220                 put_device(&vu_dev->vdev.dev);
1221         vu_dev->registered = 1;
1222         return rc;
1223
1224 error_init:
1225         os_close_file(vu_dev->sock);
1226 error_free:
1227         kfree(vu_dev);
1228         return rc;
1229 }
1230
1231 static int virtio_uml_remove(struct platform_device *pdev)
1232 {
1233         struct virtio_uml_device *vu_dev = platform_get_drvdata(pdev);
1234
1235         unregister_virtio_device(&vu_dev->vdev);
1236         return 0;
1237 }
1238
1239 /* Command line device list */
1240
1241 static void vu_cmdline_release_dev(struct device *d)
1242 {
1243 }
1244
1245 static struct device vu_cmdline_parent = {
1246         .init_name = "virtio-uml-cmdline",
1247         .release = vu_cmdline_release_dev,
1248 };
1249
1250 static bool vu_cmdline_parent_registered;
1251 static int vu_cmdline_id;
1252
1253 static int vu_unregister_cmdline_device(struct device *dev, void *data)
1254 {
1255         struct platform_device *pdev = to_platform_device(dev);
1256         struct virtio_uml_platform_data *pdata = pdev->dev.platform_data;
1257
1258         kfree(pdata->socket_path);
1259         platform_device_unregister(pdev);
1260         return 0;
1261 }
1262
1263 static void vu_conn_broken(struct work_struct *wk)
1264 {
1265         struct virtio_uml_platform_data *pdata;
1266
1267         pdata = container_of(wk, struct virtio_uml_platform_data, conn_broken_wk);
1268         vu_unregister_cmdline_device(&pdata->pdev->dev, NULL);
1269 }
1270
1271 static int vu_cmdline_set(const char *device, const struct kernel_param *kp)
1272 {
1273         const char *ids = strchr(device, ':');
1274         unsigned int virtio_device_id;
1275         int processed, consumed, err;
1276         char *socket_path;
1277         struct virtio_uml_platform_data pdata, *ppdata;
1278         struct platform_device *pdev;
1279
1280         if (!ids || ids == device)
1281                 return -EINVAL;
1282
1283         processed = sscanf(ids, ":%u%n:%d%n",
1284                            &virtio_device_id, &consumed,
1285                            &vu_cmdline_id, &consumed);
1286
1287         if (processed < 1 || ids[consumed])
1288                 return -EINVAL;
1289
1290         if (!vu_cmdline_parent_registered) {
1291                 err = device_register(&vu_cmdline_parent);
1292                 if (err) {
1293                         pr_err("Failed to register parent device!\n");
1294                         put_device(&vu_cmdline_parent);
1295                         return err;
1296                 }
1297                 vu_cmdline_parent_registered = true;
1298         }
1299
1300         socket_path = kmemdup_nul(device, ids - device, GFP_KERNEL);
1301         if (!socket_path)
1302                 return -ENOMEM;
1303
1304         pdata.virtio_device_id = (u32) virtio_device_id;
1305         pdata.socket_path = socket_path;
1306
1307         pr_info("Registering device virtio-uml.%d id=%d at %s\n",
1308                 vu_cmdline_id, virtio_device_id, socket_path);
1309
1310         pdev = platform_device_register_data(&vu_cmdline_parent, "virtio-uml",
1311                                              vu_cmdline_id++, &pdata,
1312                                              sizeof(pdata));
1313         err = PTR_ERR_OR_ZERO(pdev);
1314         if (err)
1315                 goto free;
1316
1317         ppdata = pdev->dev.platform_data;
1318         ppdata->pdev = pdev;
1319         INIT_WORK(&ppdata->conn_broken_wk, vu_conn_broken);
1320
1321         return 0;
1322
1323 free:
1324         kfree(socket_path);
1325         return err;
1326 }
1327
1328 static int vu_cmdline_get_device(struct device *dev, void *data)
1329 {
1330         struct platform_device *pdev = to_platform_device(dev);
1331         struct virtio_uml_platform_data *pdata = pdev->dev.platform_data;
1332         char *buffer = data;
1333         unsigned int len = strlen(buffer);
1334
1335         snprintf(buffer + len, PAGE_SIZE - len, "%s:%d:%d\n",
1336                  pdata->socket_path, pdata->virtio_device_id, pdev->id);
1337         return 0;
1338 }
1339
1340 static int vu_cmdline_get(char *buffer, const struct kernel_param *kp)
1341 {
1342         buffer[0] = '\0';
1343         if (vu_cmdline_parent_registered)
1344                 device_for_each_child(&vu_cmdline_parent, buffer,
1345                                       vu_cmdline_get_device);
1346         return strlen(buffer) + 1;
1347 }
1348
1349 static const struct kernel_param_ops vu_cmdline_param_ops = {
1350         .set = vu_cmdline_set,
1351         .get = vu_cmdline_get,
1352 };
1353
1354 device_param_cb(device, &vu_cmdline_param_ops, NULL, S_IRUSR);
1355 __uml_help(vu_cmdline_param_ops,
1356 "virtio_uml.device=<socket>:<virtio_id>[:<platform_id>]\n"
1357 "    Configure a virtio device over a vhost-user socket.\n"
1358 "    See virtio_ids.h for a list of possible virtio device id values.\n"
1359 "    Optionally use a specific platform_device id.\n\n"
1360 );
1361
1362
1363 static void vu_unregister_cmdline_devices(void)
1364 {
1365         if (vu_cmdline_parent_registered) {
1366                 device_for_each_child(&vu_cmdline_parent, NULL,
1367                                       vu_unregister_cmdline_device);
1368                 device_unregister(&vu_cmdline_parent);
1369                 vu_cmdline_parent_registered = false;
1370         }
1371 }
1372
1373 /* Platform driver */
1374
1375 static const struct of_device_id virtio_uml_match[] = {
1376         { .compatible = "virtio,uml", },
1377         { }
1378 };
1379 MODULE_DEVICE_TABLE(of, virtio_uml_match);
1380
1381 static int virtio_uml_suspend(struct platform_device *pdev, pm_message_t state)
1382 {
1383         struct virtio_uml_device *vu_dev = platform_get_drvdata(pdev);
1384
1385         if (!vu_dev->no_vq_suspend) {
1386                 struct virtqueue *vq;
1387
1388                 virtio_device_for_each_vq((&vu_dev->vdev), vq) {
1389                         struct virtio_uml_vq_info *info = vq->priv;
1390
1391                         info->suspended = true;
1392                         vhost_user_set_vring_enable(vu_dev, vq->index, false);
1393                 }
1394         }
1395
1396         if (!device_may_wakeup(&vu_dev->vdev.dev)) {
1397                 vu_dev->suspended = true;
1398                 return 0;
1399         }
1400
1401         return irq_set_irq_wake(vu_dev->irq, 1);
1402 }
1403
1404 static int virtio_uml_resume(struct platform_device *pdev)
1405 {
1406         struct virtio_uml_device *vu_dev = platform_get_drvdata(pdev);
1407
1408         if (!vu_dev->no_vq_suspend) {
1409                 struct virtqueue *vq;
1410
1411                 virtio_device_for_each_vq((&vu_dev->vdev), vq) {
1412                         struct virtio_uml_vq_info *info = vq->priv;
1413
1414                         info->suspended = false;
1415                         vhost_user_set_vring_enable(vu_dev, vq->index, true);
1416                 }
1417         }
1418
1419         vu_dev->suspended = false;
1420
1421         if (!device_may_wakeup(&vu_dev->vdev.dev))
1422                 return 0;
1423
1424         return irq_set_irq_wake(vu_dev->irq, 0);
1425 }
1426
1427 static struct platform_driver virtio_uml_driver = {
1428         .probe = virtio_uml_probe,
1429         .remove = virtio_uml_remove,
1430         .driver = {
1431                 .name = "virtio-uml",
1432                 .of_match_table = virtio_uml_match,
1433         },
1434         .suspend = virtio_uml_suspend,
1435         .resume = virtio_uml_resume,
1436 };
1437
1438 static int __init virtio_uml_init(void)
1439 {
1440         return platform_driver_register(&virtio_uml_driver);
1441 }
1442
1443 static void __exit virtio_uml_exit(void)
1444 {
1445         platform_driver_unregister(&virtio_uml_driver);
1446         vu_unregister_cmdline_devices();
1447 }
1448
1449 module_init(virtio_uml_init);
1450 module_exit(virtio_uml_exit);
1451 __uml_exitcall(virtio_uml_exit);
1452
1453 MODULE_DESCRIPTION("UML driver for vhost-user virtio devices");
1454 MODULE_LICENSE("GPL");