xref: /qemu/hw/usb/dev-storage.c (revision b3c09bde4842f1b157bc4431135aad4f2031e312)
1 /*
2  * USB Mass Storage Device emulation
3  *
4  * Copyright (c) 2006 CodeSourcery.
5  * Written by Paul Brook
6  *
7  * This code is licensed under the LGPL.
8  */
9 
10 #include "qemu-common.h"
11 #include "qemu-option.h"
12 #include "qemu-config.h"
13 #include "hw/usb.h"
14 #include "hw/usb/desc.h"
15 #include "hw/scsi.h"
16 #include "console.h"
17 #include "monitor.h"
18 #include "sysemu.h"
19 #include "blockdev.h"
20 
21 //#define DEBUG_MSD
22 
23 #ifdef DEBUG_MSD
24 #define DPRINTF(fmt, ...) \
25 do { printf("usb-msd: " fmt , ## __VA_ARGS__); } while (0)
26 #else
27 #define DPRINTF(fmt, ...) do {} while(0)
28 #endif
29 
30 /* USB requests.  */
31 #define MassStorageReset  0xff
32 #define GetMaxLun         0xfe
33 
34 enum USBMSDMode {
35     USB_MSDM_CBW, /* Command Block.  */
36     USB_MSDM_DATAOUT, /* Transfer data to device.  */
37     USB_MSDM_DATAIN, /* Transfer data from device.  */
38     USB_MSDM_CSW /* Command Status.  */
39 };
40 
41 struct usb_msd_csw {
42     uint32_t sig;
43     uint32_t tag;
44     uint32_t residue;
45     uint8_t status;
46 };
47 
48 typedef struct {
49     USBDevice dev;
50     enum USBMSDMode mode;
51     uint32_t scsi_len;
52     uint8_t *scsi_buf;
53     uint32_t data_len;
54     uint32_t residue;
55     struct usb_msd_csw csw;
56     SCSIRequest *req;
57     SCSIBus bus;
58     BlockConf conf;
59     char *serial;
60     SCSIDevice *scsi_dev;
61     uint32_t removable;
62     /* For async completion.  */
63     USBPacket *packet;
64 } MSDState;
65 
66 struct usb_msd_cbw {
67     uint32_t sig;
68     uint32_t tag;
69     uint32_t data_len;
70     uint8_t flags;
71     uint8_t lun;
72     uint8_t cmd_len;
73     uint8_t cmd[16];
74 };
75 
76 enum {
77     STR_MANUFACTURER = 1,
78     STR_PRODUCT,
79     STR_SERIALNUMBER,
80     STR_CONFIG_FULL,
81     STR_CONFIG_HIGH,
82 };
83 
84 static const USBDescStrings desc_strings = {
85     [STR_MANUFACTURER] = "QEMU " QEMU_VERSION,
86     [STR_PRODUCT]      = "QEMU USB HARDDRIVE",
87     [STR_SERIALNUMBER] = "1",
88     [STR_CONFIG_FULL]  = "Full speed config (usb 1.1)",
89     [STR_CONFIG_HIGH]  = "High speed config (usb 2.0)",
90 };
91 
92 static const USBDescIface desc_iface_full = {
93     .bInterfaceNumber              = 0,
94     .bNumEndpoints                 = 2,
95     .bInterfaceClass               = USB_CLASS_MASS_STORAGE,
96     .bInterfaceSubClass            = 0x06, /* SCSI */
97     .bInterfaceProtocol            = 0x50, /* Bulk */
98     .eps = (USBDescEndpoint[]) {
99         {
100             .bEndpointAddress      = USB_DIR_IN | 0x01,
101             .bmAttributes          = USB_ENDPOINT_XFER_BULK,
102             .wMaxPacketSize        = 64,
103         },{
104             .bEndpointAddress      = USB_DIR_OUT | 0x02,
105             .bmAttributes          = USB_ENDPOINT_XFER_BULK,
106             .wMaxPacketSize        = 64,
107         },
108     }
109 };
110 
111 static const USBDescDevice desc_device_full = {
112     .bcdUSB                        = 0x0200,
113     .bMaxPacketSize0               = 8,
114     .bNumConfigurations            = 1,
115     .confs = (USBDescConfig[]) {
116         {
117             .bNumInterfaces        = 1,
118             .bConfigurationValue   = 1,
119             .iConfiguration        = STR_CONFIG_FULL,
120             .bmAttributes          = 0xc0,
121             .nif = 1,
122             .ifs = &desc_iface_full,
123         },
124     },
125 };
126 
127 static const USBDescIface desc_iface_high = {
128     .bInterfaceNumber              = 0,
129     .bNumEndpoints                 = 2,
130     .bInterfaceClass               = USB_CLASS_MASS_STORAGE,
131     .bInterfaceSubClass            = 0x06, /* SCSI */
132     .bInterfaceProtocol            = 0x50, /* Bulk */
133     .eps = (USBDescEndpoint[]) {
134         {
135             .bEndpointAddress      = USB_DIR_IN | 0x01,
136             .bmAttributes          = USB_ENDPOINT_XFER_BULK,
137             .wMaxPacketSize        = 512,
138         },{
139             .bEndpointAddress      = USB_DIR_OUT | 0x02,
140             .bmAttributes          = USB_ENDPOINT_XFER_BULK,
141             .wMaxPacketSize        = 512,
142         },
143     }
144 };
145 
146 static const USBDescDevice desc_device_high = {
147     .bcdUSB                        = 0x0200,
148     .bMaxPacketSize0               = 64,
149     .bNumConfigurations            = 1,
150     .confs = (USBDescConfig[]) {
151         {
152             .bNumInterfaces        = 1,
153             .bConfigurationValue   = 1,
154             .iConfiguration        = STR_CONFIG_HIGH,
155             .bmAttributes          = 0xc0,
156             .nif = 1,
157             .ifs = &desc_iface_high,
158         },
159     },
160 };
161 
162 static const USBDesc desc = {
163     .id = {
164         .idVendor          = 0x46f4, /* CRC16() of "QEMU" */
165         .idProduct         = 0x0001,
166         .bcdDevice         = 0,
167         .iManufacturer     = STR_MANUFACTURER,
168         .iProduct          = STR_PRODUCT,
169         .iSerialNumber     = STR_SERIALNUMBER,
170     },
171     .full = &desc_device_full,
172     .high = &desc_device_high,
173     .str  = desc_strings,
174 };
175 
176 static void usb_msd_copy_data(MSDState *s, USBPacket *p)
177 {
178     uint32_t len;
179     len = p->iov.size - p->result;
180     if (len > s->scsi_len)
181         len = s->scsi_len;
182     usb_packet_copy(p, s->scsi_buf, len);
183     s->scsi_len -= len;
184     s->scsi_buf += len;
185     s->data_len -= len;
186     if (s->scsi_len == 0 || s->data_len == 0) {
187         scsi_req_continue(s->req);
188     }
189 }
190 
191 static void usb_msd_send_status(MSDState *s, USBPacket *p)
192 {
193     int len;
194 
195     DPRINTF("Command status %d tag 0x%x, len %zd\n",
196             s->csw.status, le32_to_cpu(s->csw.tag), p->iov.size);
197 
198     assert(s->csw.sig == cpu_to_le32(0x53425355));
199     len = MIN(sizeof(s->csw), p->iov.size);
200     usb_packet_copy(p, &s->csw, len);
201     memset(&s->csw, 0, sizeof(s->csw));
202 }
203 
204 static void usb_msd_transfer_data(SCSIRequest *req, uint32_t len)
205 {
206     MSDState *s = DO_UPCAST(MSDState, dev.qdev, req->bus->qbus.parent);
207     USBPacket *p = s->packet;
208 
209     assert((s->mode == USB_MSDM_DATAOUT) == (req->cmd.mode == SCSI_XFER_TO_DEV));
210     s->scsi_len = len;
211     s->scsi_buf = scsi_req_get_buf(req);
212     if (p) {
213         usb_msd_copy_data(s, p);
214         p = s->packet;
215         if (p && p->result == p->iov.size) {
216             /* Set s->packet to NULL before calling usb_packet_complete
217                because another request may be issued before
218                usb_packet_complete returns.  */
219             DPRINTF("Packet complete %p\n", p);
220             s->packet = NULL;
221             usb_packet_complete(&s->dev, p);
222         }
223     }
224 }
225 
226 static void usb_msd_command_complete(SCSIRequest *req, uint32_t status, size_t resid)
227 {
228     MSDState *s = DO_UPCAST(MSDState, dev.qdev, req->bus->qbus.parent);
229     USBPacket *p = s->packet;
230 
231     DPRINTF("Command complete %d tag 0x%x\n", status, req->tag);
232     s->residue = s->data_len;
233 
234     s->csw.sig = cpu_to_le32(0x53425355);
235     s->csw.tag = cpu_to_le32(req->tag);
236     s->csw.residue = cpu_to_le32(s->residue);
237     s->csw.status = status != 0;
238 
239     if (s->packet) {
240         if (s->data_len == 0 && s->mode == USB_MSDM_DATAOUT) {
241             /* A deferred packet with no write data remaining must be
242                the status read packet.  */
243             usb_msd_send_status(s, p);
244             s->mode = USB_MSDM_CBW;
245         } else {
246             if (s->data_len) {
247                 int len = (p->iov.size - p->result);
248                 usb_packet_skip(p, len);
249                 s->data_len -= len;
250             }
251             if (s->data_len == 0) {
252                 s->mode = USB_MSDM_CSW;
253             }
254         }
255         s->packet = NULL;
256         usb_packet_complete(&s->dev, p);
257     } else if (s->data_len == 0) {
258         s->mode = USB_MSDM_CSW;
259     }
260     scsi_req_unref(req);
261     s->req = NULL;
262 }
263 
264 static void usb_msd_request_cancelled(SCSIRequest *req)
265 {
266     MSDState *s = DO_UPCAST(MSDState, dev.qdev, req->bus->qbus.parent);
267 
268     if (req == s->req) {
269         scsi_req_unref(s->req);
270         s->req = NULL;
271         s->packet = NULL;
272         s->scsi_len = 0;
273     }
274 }
275 
276 static void usb_msd_handle_reset(USBDevice *dev)
277 {
278     MSDState *s = (MSDState *)dev;
279 
280     DPRINTF("Reset\n");
281     if (s->req) {
282         scsi_req_cancel(s->req);
283     }
284     assert(s->req == NULL);
285 
286     if (s->packet) {
287         USBPacket *p = s->packet;
288         s->packet = NULL;
289         p->result = USB_RET_STALL;
290         usb_packet_complete(dev, p);
291     }
292 
293     s->mode = USB_MSDM_CBW;
294 }
295 
296 static int usb_msd_handle_control(USBDevice *dev, USBPacket *p,
297                int request, int value, int index, int length, uint8_t *data)
298 {
299     MSDState *s = (MSDState *)dev;
300     int ret;
301 
302     ret = usb_desc_handle_control(dev, p, request, value, index, length, data);
303     if (ret >= 0) {
304         return ret;
305     }
306 
307     ret = 0;
308     switch (request) {
309     case EndpointOutRequest | USB_REQ_CLEAR_FEATURE:
310         ret = 0;
311         break;
312         /* Class specific requests.  */
313     case ClassInterfaceOutRequest | MassStorageReset:
314         /* Reset state ready for the next CBW.  */
315         s->mode = USB_MSDM_CBW;
316         ret = 0;
317         break;
318     case ClassInterfaceRequest | GetMaxLun:
319         data[0] = 0;
320         ret = 1;
321         break;
322     default:
323         ret = USB_RET_STALL;
324         break;
325     }
326     return ret;
327 }
328 
329 static void usb_msd_cancel_io(USBDevice *dev, USBPacket *p)
330 {
331     MSDState *s = DO_UPCAST(MSDState, dev, dev);
332 
333     if (s->req) {
334         scsi_req_cancel(s->req);
335     }
336 }
337 
338 static int usb_msd_handle_data(USBDevice *dev, USBPacket *p)
339 {
340     MSDState *s = (MSDState *)dev;
341     uint32_t tag;
342     int ret = 0;
343     struct usb_msd_cbw cbw;
344     uint8_t devep = p->ep->nr;
345 
346     switch (p->pid) {
347     case USB_TOKEN_OUT:
348         if (devep != 2)
349             goto fail;
350 
351         switch (s->mode) {
352         case USB_MSDM_CBW:
353             if (p->iov.size != 31) {
354                 fprintf(stderr, "usb-msd: Bad CBW size");
355                 goto fail;
356             }
357             usb_packet_copy(p, &cbw, 31);
358             if (le32_to_cpu(cbw.sig) != 0x43425355) {
359                 fprintf(stderr, "usb-msd: Bad signature %08x\n",
360                         le32_to_cpu(cbw.sig));
361                 goto fail;
362             }
363             DPRINTF("Command on LUN %d\n", cbw.lun);
364             if (cbw.lun != 0) {
365                 fprintf(stderr, "usb-msd: Bad LUN %d\n", cbw.lun);
366                 goto fail;
367             }
368             tag = le32_to_cpu(cbw.tag);
369             s->data_len = le32_to_cpu(cbw.data_len);
370             if (s->data_len == 0) {
371                 s->mode = USB_MSDM_CSW;
372             } else if (cbw.flags & 0x80) {
373                 s->mode = USB_MSDM_DATAIN;
374             } else {
375                 s->mode = USB_MSDM_DATAOUT;
376             }
377             DPRINTF("Command tag 0x%x flags %08x len %d data %d\n",
378                     tag, cbw.flags, cbw.cmd_len, s->data_len);
379             s->residue = 0;
380             s->scsi_len = 0;
381             s->req = scsi_req_new(s->scsi_dev, tag, 0, cbw.cmd, NULL);
382             scsi_req_enqueue(s->req);
383             if (s->req && s->req->cmd.xfer != SCSI_XFER_NONE) {
384                 scsi_req_continue(s->req);
385             }
386             ret = p->result;
387             break;
388 
389         case USB_MSDM_DATAOUT:
390             DPRINTF("Data out %zd/%d\n", p->iov.size, s->data_len);
391             if (p->iov.size > s->data_len) {
392                 goto fail;
393             }
394 
395             if (s->scsi_len) {
396                 usb_msd_copy_data(s, p);
397             }
398             if (s->residue) {
399                 int len = p->iov.size - p->result;
400                 if (len) {
401                     usb_packet_skip(p, len);
402                     s->data_len -= len;
403                     if (s->data_len == 0) {
404                         s->mode = USB_MSDM_CSW;
405                     }
406                 }
407             }
408             if (p->result < p->iov.size) {
409                 DPRINTF("Deferring packet %p\n", p);
410                 s->packet = p;
411                 ret = USB_RET_ASYNC;
412             } else {
413                 ret = p->result;
414             }
415             break;
416 
417         default:
418             DPRINTF("Unexpected write (len %zd)\n", p->iov.size);
419             goto fail;
420         }
421         break;
422 
423     case USB_TOKEN_IN:
424         if (devep != 1)
425             goto fail;
426 
427         switch (s->mode) {
428         case USB_MSDM_DATAOUT:
429             if (s->data_len != 0 || p->iov.size < 13) {
430                 goto fail;
431             }
432             /* Waiting for SCSI write to complete.  */
433             s->packet = p;
434             ret = USB_RET_ASYNC;
435             break;
436 
437         case USB_MSDM_CSW:
438             if (p->iov.size < 13) {
439                 goto fail;
440             }
441 
442             if (s->req) {
443                 /* still in flight */
444                 s->packet = p;
445                 ret = USB_RET_ASYNC;
446             } else {
447                 usb_msd_send_status(s, p);
448                 s->mode = USB_MSDM_CBW;
449                 ret = 13;
450             }
451             break;
452 
453         case USB_MSDM_DATAIN:
454             DPRINTF("Data in %zd/%d, scsi_len %d\n",
455                     p->iov.size, s->data_len, s->scsi_len);
456             if (s->scsi_len) {
457                 usb_msd_copy_data(s, p);
458             }
459             if (s->residue) {
460                 int len = p->iov.size - p->result;
461                 if (len) {
462                     usb_packet_skip(p, len);
463                     s->data_len -= len;
464                     if (s->data_len == 0) {
465                         s->mode = USB_MSDM_CSW;
466                     }
467                 }
468             }
469             if (p->result < p->iov.size) {
470                 DPRINTF("Deferring packet %p\n", p);
471                 s->packet = p;
472                 ret = USB_RET_ASYNC;
473             } else {
474                 ret = p->result;
475             }
476             break;
477 
478         default:
479             DPRINTF("Unexpected read (len %zd)\n", p->iov.size);
480             goto fail;
481         }
482         break;
483 
484     default:
485         DPRINTF("Bad token\n");
486     fail:
487         ret = USB_RET_STALL;
488         break;
489     }
490 
491     return ret;
492 }
493 
494 static void usb_msd_password_cb(void *opaque, int err)
495 {
496     MSDState *s = opaque;
497 
498     if (!err)
499         err = usb_device_attach(&s->dev);
500 
501     if (err)
502         qdev_unplug(&s->dev.qdev, NULL);
503 }
504 
505 static const struct SCSIBusInfo usb_msd_scsi_info = {
506     .tcq = false,
507     .max_target = 0,
508     .max_lun = 0,
509 
510     .transfer_data = usb_msd_transfer_data,
511     .complete = usb_msd_command_complete,
512     .cancel = usb_msd_request_cancelled
513 };
514 
515 static int usb_msd_initfn(USBDevice *dev)
516 {
517     MSDState *s = DO_UPCAST(MSDState, dev, dev);
518     BlockDriverState *bs = s->conf.bs;
519     DriveInfo *dinfo;
520 
521     if (!bs) {
522         error_report("drive property not set");
523         return -1;
524     }
525 
526     /*
527      * Hack alert: this pretends to be a block device, but it's really
528      * a SCSI bus that can serve only a single device, which it
529      * creates automatically.  But first it needs to detach from its
530      * blockdev, or else scsi_bus_legacy_add_drive() dies when it
531      * attaches again.
532      *
533      * The hack is probably a bad idea.
534      */
535     bdrv_detach_dev(bs, &s->dev.qdev);
536     s->conf.bs = NULL;
537 
538     if (!s->serial) {
539         /* try to fall back to value set with legacy -drive serial=... */
540         dinfo = drive_get_by_blockdev(bs);
541         if (*dinfo->serial) {
542             s->serial = strdup(dinfo->serial);
543         }
544     }
545     if (s->serial) {
546         usb_desc_set_string(dev, STR_SERIALNUMBER, s->serial);
547     }
548 
549     usb_desc_init(dev);
550     scsi_bus_new(&s->bus, &s->dev.qdev, &usb_msd_scsi_info);
551     s->scsi_dev = scsi_bus_legacy_add_drive(&s->bus, bs, 0, !!s->removable,
552                                             s->conf.bootindex);
553     if (!s->scsi_dev) {
554         return -1;
555     }
556     s->bus.qbus.allow_hotplug = 0;
557     usb_msd_handle_reset(dev);
558 
559     if (bdrv_key_required(bs)) {
560         if (cur_mon) {
561             monitor_read_bdrv_key_start(cur_mon, bs, usb_msd_password_cb, s);
562             s->dev.auto_attach = 0;
563         } else {
564             autostart = 0;
565         }
566     }
567 
568     return 0;
569 }
570 
571 static USBDevice *usb_msd_init(USBBus *bus, const char *filename)
572 {
573     static int nr=0;
574     char id[8];
575     QemuOpts *opts;
576     DriveInfo *dinfo;
577     USBDevice *dev;
578     const char *p1;
579     char fmt[32];
580 
581     /* parse -usbdevice disk: syntax into drive opts */
582     snprintf(id, sizeof(id), "usb%d", nr++);
583     opts = qemu_opts_create(qemu_find_opts("drive"), id, 0);
584 
585     p1 = strchr(filename, ':');
586     if (p1++) {
587         const char *p2;
588 
589         if (strstart(filename, "format=", &p2)) {
590             int len = MIN(p1 - p2, sizeof(fmt));
591             pstrcpy(fmt, len, p2);
592             qemu_opt_set(opts, "format", fmt);
593         } else if (*filename != ':') {
594             printf("unrecognized USB mass-storage option %s\n", filename);
595             return NULL;
596         }
597         filename = p1;
598     }
599     if (!*filename) {
600         printf("block device specification needed\n");
601         return NULL;
602     }
603     qemu_opt_set(opts, "file", filename);
604     qemu_opt_set(opts, "if", "none");
605 
606     /* create host drive */
607     dinfo = drive_init(opts, 0);
608     if (!dinfo) {
609         qemu_opts_del(opts);
610         return NULL;
611     }
612 
613     /* create guest device */
614     dev = usb_create(bus, "usb-storage");
615     if (!dev) {
616         return NULL;
617     }
618     if (qdev_prop_set_drive(&dev->qdev, "drive", dinfo->bdrv) < 0) {
619         qdev_free(&dev->qdev);
620         return NULL;
621     }
622     if (qdev_init(&dev->qdev) < 0)
623         return NULL;
624 
625     return dev;
626 }
627 
628 static const VMStateDescription vmstate_usb_msd = {
629     .name = "usb-storage",
630     .unmigratable = 1, /* FIXME: handle transactions which are in flight */
631     .version_id = 1,
632     .minimum_version_id = 1,
633     .fields = (VMStateField []) {
634         VMSTATE_USB_DEVICE(dev, MSDState),
635         VMSTATE_END_OF_LIST()
636     }
637 };
638 
639 static Property msd_properties[] = {
640     DEFINE_BLOCK_PROPERTIES(MSDState, conf),
641     DEFINE_PROP_STRING("serial", MSDState, serial),
642     DEFINE_PROP_BIT("removable", MSDState, removable, 0, false),
643     DEFINE_PROP_END_OF_LIST(),
644 };
645 
646 static void usb_msd_class_initfn(ObjectClass *klass, void *data)
647 {
648     DeviceClass *dc = DEVICE_CLASS(klass);
649     USBDeviceClass *uc = USB_DEVICE_CLASS(klass);
650 
651     uc->init           = usb_msd_initfn;
652     uc->product_desc   = "QEMU USB MSD";
653     uc->usb_desc       = &desc;
654     uc->cancel_packet  = usb_msd_cancel_io;
655     uc->handle_attach  = usb_desc_attach;
656     uc->handle_reset   = usb_msd_handle_reset;
657     uc->handle_control = usb_msd_handle_control;
658     uc->handle_data    = usb_msd_handle_data;
659     dc->fw_name = "storage";
660     dc->vmsd = &vmstate_usb_msd;
661     dc->props = msd_properties;
662 }
663 
664 static TypeInfo msd_info = {
665     .name          = "usb-storage",
666     .parent        = TYPE_USB_DEVICE,
667     .instance_size = sizeof(MSDState),
668     .class_init    = usb_msd_class_initfn,
669 };
670 
671 static void usb_msd_register_types(void)
672 {
673     type_register_static(&msd_info);
674     usb_legacy_register("usb-storage", "disk", usb_msd_init);
675 }
676 
677 type_init(usb_msd_register_types)
678