qemu-e2k/hw/scsi-bus.c
Paolo Bonzini d800040fb4 scsi: fix tracing of scsi requests with simple backend
The simple backend only supports a maximum of 6 arguments.  Split the
scsi_req_parsed event in two parts to cope with the limit.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2011-06-05 15:05:35 +00:00

732 lines
20 KiB
C

#include "hw.h"
#include "qemu-error.h"
#include "scsi.h"
#include "scsi-defs.h"
#include "qdev.h"
#include "blockdev.h"
#include "trace.h"
static char *scsibus_get_fw_dev_path(DeviceState *dev);
static struct BusInfo scsi_bus_info = {
.name = "SCSI",
.size = sizeof(SCSIBus),
.get_fw_dev_path = scsibus_get_fw_dev_path,
.props = (Property[]) {
DEFINE_PROP_UINT32("scsi-id", SCSIDevice, id, -1),
DEFINE_PROP_END_OF_LIST(),
},
};
static int next_scsi_bus;
/* Create a scsi bus, and attach devices to it. */
void scsi_bus_new(SCSIBus *bus, DeviceState *host, int tcq, int ndev,
const SCSIBusOps *ops)
{
qbus_create_inplace(&bus->qbus, &scsi_bus_info, host, NULL);
bus->busnr = next_scsi_bus++;
bus->tcq = tcq;
bus->ndev = ndev;
bus->ops = ops;
bus->qbus.allow_hotplug = 1;
}
static int scsi_qdev_init(DeviceState *qdev, DeviceInfo *base)
{
SCSIDevice *dev = DO_UPCAST(SCSIDevice, qdev, qdev);
SCSIDeviceInfo *info = DO_UPCAST(SCSIDeviceInfo, qdev, base);
SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
int rc = -1;
if (dev->id == -1) {
for (dev->id = 0; dev->id < bus->ndev; dev->id++) {
if (bus->devs[dev->id] == NULL)
break;
}
}
if (dev->id >= bus->ndev) {
error_report("bad scsi device id: %d", dev->id);
goto err;
}
if (bus->devs[dev->id]) {
qdev_free(&bus->devs[dev->id]->qdev);
}
bus->devs[dev->id] = dev;
dev->info = info;
QTAILQ_INIT(&dev->requests);
rc = dev->info->init(dev);
if (rc != 0) {
bus->devs[dev->id] = NULL;
}
err:
return rc;
}
static int scsi_qdev_exit(DeviceState *qdev)
{
SCSIDevice *dev = DO_UPCAST(SCSIDevice, qdev, qdev);
SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, dev->qdev.parent_bus);
assert(bus->devs[dev->id] != NULL);
if (bus->devs[dev->id]->info->destroy) {
bus->devs[dev->id]->info->destroy(bus->devs[dev->id]);
}
bus->devs[dev->id] = NULL;
return 0;
}
void scsi_qdev_register(SCSIDeviceInfo *info)
{
info->qdev.bus_info = &scsi_bus_info;
info->qdev.init = scsi_qdev_init;
info->qdev.unplug = qdev_simple_unplug_cb;
info->qdev.exit = scsi_qdev_exit;
qdev_register(&info->qdev);
}
/* handle legacy '-drive if=scsi,...' cmd line args */
SCSIDevice *scsi_bus_legacy_add_drive(SCSIBus *bus, BlockDriverState *bdrv,
int unit, bool removable)
{
const char *driver;
DeviceState *dev;
driver = bdrv_is_sg(bdrv) ? "scsi-generic" : "scsi-disk";
dev = qdev_create(&bus->qbus, driver);
qdev_prop_set_uint32(dev, "scsi-id", unit);
if (qdev_prop_exists(dev, "removable")) {
qdev_prop_set_bit(dev, "removable", removable);
}
if (qdev_prop_set_drive(dev, "drive", bdrv) < 0) {
qdev_free(dev);
return NULL;
}
if (qdev_init(dev) < 0)
return NULL;
return DO_UPCAST(SCSIDevice, qdev, dev);
}
int scsi_bus_legacy_handle_cmdline(SCSIBus *bus)
{
Location loc;
DriveInfo *dinfo;
int res = 0, unit;
loc_push_none(&loc);
for (unit = 0; unit < bus->ndev; unit++) {
dinfo = drive_get(IF_SCSI, bus->busnr, unit);
if (dinfo == NULL) {
continue;
}
qemu_opts_loc_restore(dinfo->opts);
if (!scsi_bus_legacy_add_drive(bus, dinfo->bdrv, unit, false)) {
res = -1;
break;
}
}
loc_pop(&loc);
return res;
}
SCSIRequest *scsi_req_alloc(size_t size, SCSIDevice *d, uint32_t tag, uint32_t lun)
{
SCSIRequest *req;
req = qemu_mallocz(size);
req->refcount = 1;
req->bus = scsi_bus_from_device(d);
req->dev = d;
req->tag = tag;
req->lun = lun;
req->status = -1;
trace_scsi_req_alloc(req->dev->id, req->lun, req->tag);
return req;
}
SCSIRequest *scsi_req_new(SCSIDevice *d, uint32_t tag, uint32_t lun)
{
return d->info->alloc_req(d, tag, lun);
}
uint8_t *scsi_req_get_buf(SCSIRequest *req)
{
return req->dev->info->get_buf(req);
}
int scsi_req_get_sense(SCSIRequest *req, uint8_t *buf, int len)
{
if (req->dev->info->get_sense) {
return req->dev->info->get_sense(req, buf, len);
} else {
return 0;
}
}
int32_t scsi_req_enqueue(SCSIRequest *req, uint8_t *buf)
{
int32_t rc;
assert(!req->enqueued);
scsi_req_ref(req);
req->enqueued = true;
QTAILQ_INSERT_TAIL(&req->dev->requests, req, next);
scsi_req_ref(req);
rc = req->dev->info->send_command(req, buf);
scsi_req_unref(req);
return rc;
}
static void scsi_req_dequeue(SCSIRequest *req)
{
trace_scsi_req_dequeue(req->dev->id, req->lun, req->tag);
if (req->enqueued) {
QTAILQ_REMOVE(&req->dev->requests, req, next);
req->enqueued = false;
scsi_req_unref(req);
}
}
static int scsi_req_length(SCSIRequest *req, uint8_t *cmd)
{
switch (cmd[0] >> 5) {
case 0:
req->cmd.xfer = cmd[4];
req->cmd.len = 6;
/* length 0 means 256 blocks */
if (req->cmd.xfer == 0)
req->cmd.xfer = 256;
break;
case 1:
case 2:
req->cmd.xfer = cmd[8] | (cmd[7] << 8);
req->cmd.len = 10;
break;
case 4:
req->cmd.xfer = cmd[13] | (cmd[12] << 8) | (cmd[11] << 16) | (cmd[10] << 24);
req->cmd.len = 16;
break;
case 5:
req->cmd.xfer = cmd[9] | (cmd[8] << 8) | (cmd[7] << 16) | (cmd[6] << 24);
req->cmd.len = 12;
break;
default:
trace_scsi_req_parse_bad(req->dev->id, req->lun, req->tag, cmd[0]);
return -1;
}
switch(cmd[0]) {
case TEST_UNIT_READY:
case REZERO_UNIT:
case START_STOP:
case SEEK_6:
case WRITE_FILEMARKS:
case SPACE:
case RESERVE:
case RELEASE:
case ERASE:
case ALLOW_MEDIUM_REMOVAL:
case VERIFY:
case SEEK_10:
case SYNCHRONIZE_CACHE:
case LOCK_UNLOCK_CACHE:
case LOAD_UNLOAD:
case SET_CD_SPEED:
case SET_LIMITS:
case WRITE_LONG:
case MOVE_MEDIUM:
case UPDATE_BLOCK:
req->cmd.xfer = 0;
break;
case MODE_SENSE:
break;
case WRITE_SAME:
req->cmd.xfer = 1;
break;
case READ_CAPACITY:
req->cmd.xfer = 8;
break;
case READ_BLOCK_LIMITS:
req->cmd.xfer = 6;
break;
case READ_POSITION:
req->cmd.xfer = 20;
break;
case SEND_VOLUME_TAG:
req->cmd.xfer *= 40;
break;
case MEDIUM_SCAN:
req->cmd.xfer *= 8;
break;
case WRITE_10:
case WRITE_VERIFY:
case WRITE_6:
case WRITE_12:
case WRITE_VERIFY_12:
case WRITE_16:
case WRITE_VERIFY_16:
req->cmd.xfer *= req->dev->blocksize;
break;
case READ_10:
case READ_6:
case READ_REVERSE:
case RECOVER_BUFFERED_DATA:
case READ_12:
case READ_16:
req->cmd.xfer *= req->dev->blocksize;
break;
case INQUIRY:
req->cmd.xfer = cmd[4] | (cmd[3] << 8);
break;
case MAINTENANCE_OUT:
case MAINTENANCE_IN:
if (req->dev->type == TYPE_ROM) {
/* GPCMD_REPORT_KEY and GPCMD_SEND_KEY from multi media commands */
req->cmd.xfer = cmd[9] | (cmd[8] << 8);
}
break;
}
return 0;
}
static int scsi_req_stream_length(SCSIRequest *req, uint8_t *cmd)
{
switch(cmd[0]) {
/* stream commands */
case READ_6:
case READ_REVERSE:
case RECOVER_BUFFERED_DATA:
case WRITE_6:
req->cmd.len = 6;
req->cmd.xfer = cmd[4] | (cmd[3] << 8) | (cmd[2] << 16);
if (cmd[1] & 0x01) /* fixed */
req->cmd.xfer *= req->dev->blocksize;
break;
case REWIND:
case START_STOP:
req->cmd.len = 6;
req->cmd.xfer = 0;
break;
/* generic commands */
default:
return scsi_req_length(req, cmd);
}
return 0;
}
static void scsi_req_xfer_mode(SCSIRequest *req)
{
switch (req->cmd.buf[0]) {
case WRITE_6:
case WRITE_10:
case WRITE_VERIFY:
case WRITE_12:
case WRITE_VERIFY_12:
case WRITE_16:
case WRITE_VERIFY_16:
case COPY:
case COPY_VERIFY:
case COMPARE:
case CHANGE_DEFINITION:
case LOG_SELECT:
case MODE_SELECT:
case MODE_SELECT_10:
case SEND_DIAGNOSTIC:
case WRITE_BUFFER:
case FORMAT_UNIT:
case REASSIGN_BLOCKS:
case SEARCH_EQUAL:
case SEARCH_HIGH:
case SEARCH_LOW:
case UPDATE_BLOCK:
case WRITE_LONG:
case WRITE_SAME:
case SEARCH_HIGH_12:
case SEARCH_EQUAL_12:
case SEARCH_LOW_12:
case SET_WINDOW:
case MEDIUM_SCAN:
case SEND_VOLUME_TAG:
case WRITE_LONG_2:
case PERSISTENT_RESERVE_OUT:
case MAINTENANCE_OUT:
req->cmd.mode = SCSI_XFER_TO_DEV;
break;
default:
if (req->cmd.xfer)
req->cmd.mode = SCSI_XFER_FROM_DEV;
else {
req->cmd.mode = SCSI_XFER_NONE;
}
break;
}
}
static uint64_t scsi_req_lba(SCSIRequest *req)
{
uint8_t *buf = req->cmd.buf;
uint64_t lba;
switch (buf[0] >> 5) {
case 0:
lba = (uint64_t) buf[3] | ((uint64_t) buf[2] << 8) |
(((uint64_t) buf[1] & 0x1f) << 16);
break;
case 1:
case 2:
lba = (uint64_t) buf[5] | ((uint64_t) buf[4] << 8) |
((uint64_t) buf[3] << 16) | ((uint64_t) buf[2] << 24);
break;
case 4:
lba = (uint64_t) buf[9] | ((uint64_t) buf[8] << 8) |
((uint64_t) buf[7] << 16) | ((uint64_t) buf[6] << 24) |
((uint64_t) buf[5] << 32) | ((uint64_t) buf[4] << 40) |
((uint64_t) buf[3] << 48) | ((uint64_t) buf[2] << 56);
break;
case 5:
lba = (uint64_t) buf[5] | ((uint64_t) buf[4] << 8) |
((uint64_t) buf[3] << 16) | ((uint64_t) buf[2] << 24);
break;
default:
lba = -1;
}
return lba;
}
int scsi_req_parse(SCSIRequest *req, uint8_t *buf)
{
int rc;
if (req->dev->type == TYPE_TAPE) {
rc = scsi_req_stream_length(req, buf);
} else {
rc = scsi_req_length(req, buf);
}
if (rc != 0)
return rc;
memcpy(req->cmd.buf, buf, req->cmd.len);
scsi_req_xfer_mode(req);
req->cmd.lba = scsi_req_lba(req);
trace_scsi_req_parsed(req->dev->id, req->lun, req->tag, buf[0],
req->cmd.mode, req->cmd.xfer);
if (req->cmd.lba != -1) {
trace_scsi_req_parsed_lba(req->dev->id, req->lun, req->tag, buf[0],
req->cmd.lba);
}
return 0;
}
/*
* Predefined sense codes
*/
/* No sense data available */
const struct SCSISense sense_code_NO_SENSE = {
.key = NO_SENSE , .asc = 0x00 , .ascq = 0x00
};
/* LUN not ready, Manual intervention required */
const struct SCSISense sense_code_LUN_NOT_READY = {
.key = NOT_READY, .asc = 0x04, .ascq = 0x03
};
/* LUN not ready, Medium not present */
const struct SCSISense sense_code_NO_MEDIUM = {
.key = NOT_READY, .asc = 0x3a, .ascq = 0x00
};
/* Hardware error, internal target failure */
const struct SCSISense sense_code_TARGET_FAILURE = {
.key = HARDWARE_ERROR, .asc = 0x44, .ascq = 0x00
};
/* Illegal request, invalid command operation code */
const struct SCSISense sense_code_INVALID_OPCODE = {
.key = ILLEGAL_REQUEST, .asc = 0x20, .ascq = 0x00
};
/* Illegal request, LBA out of range */
const struct SCSISense sense_code_LBA_OUT_OF_RANGE = {
.key = ILLEGAL_REQUEST, .asc = 0x21, .ascq = 0x00
};
/* Illegal request, Invalid field in CDB */
const struct SCSISense sense_code_INVALID_FIELD = {
.key = ILLEGAL_REQUEST, .asc = 0x24, .ascq = 0x00
};
/* Illegal request, LUN not supported */
const struct SCSISense sense_code_LUN_NOT_SUPPORTED = {
.key = ILLEGAL_REQUEST, .asc = 0x25, .ascq = 0x00
};
/* Command aborted, I/O process terminated */
const struct SCSISense sense_code_IO_ERROR = {
.key = ABORTED_COMMAND, .asc = 0x00, .ascq = 0x06
};
/* Command aborted, I_T Nexus loss occurred */
const struct SCSISense sense_code_I_T_NEXUS_LOSS = {
.key = ABORTED_COMMAND, .asc = 0x29, .ascq = 0x07
};
/* Command aborted, Logical Unit failure */
const struct SCSISense sense_code_LUN_FAILURE = {
.key = ABORTED_COMMAND, .asc = 0x3e, .ascq = 0x01
};
/*
* scsi_build_sense
*
* Build a sense buffer
*/
int scsi_build_sense(SCSISense sense, uint8_t *buf, int len, int fixed)
{
if (!fixed && len < 8) {
return 0;
}
memset(buf, 0, len);
if (fixed) {
/* Return fixed format sense buffer */
buf[0] = 0xf0;
buf[2] = sense.key;
buf[7] = 7;
buf[12] = sense.asc;
buf[13] = sense.ascq;
return MIN(len, 18);
} else {
/* Return descriptor format sense buffer */
buf[0] = 0x72;
buf[1] = sense.key;
buf[2] = sense.asc;
buf[3] = sense.ascq;
return 8;
}
}
static const char *scsi_command_name(uint8_t cmd)
{
static const char *names[] = {
[ TEST_UNIT_READY ] = "TEST_UNIT_READY",
[ REZERO_UNIT ] = "REZERO_UNIT",
/* REWIND and REZERO_UNIT use the same operation code */
[ REQUEST_SENSE ] = "REQUEST_SENSE",
[ FORMAT_UNIT ] = "FORMAT_UNIT",
[ READ_BLOCK_LIMITS ] = "READ_BLOCK_LIMITS",
[ REASSIGN_BLOCKS ] = "REASSIGN_BLOCKS",
[ READ_6 ] = "READ_6",
[ WRITE_6 ] = "WRITE_6",
[ SEEK_6 ] = "SEEK_6",
[ READ_REVERSE ] = "READ_REVERSE",
[ WRITE_FILEMARKS ] = "WRITE_FILEMARKS",
[ SPACE ] = "SPACE",
[ INQUIRY ] = "INQUIRY",
[ RECOVER_BUFFERED_DATA ] = "RECOVER_BUFFERED_DATA",
[ MAINTENANCE_IN ] = "MAINTENANCE_IN",
[ MAINTENANCE_OUT ] = "MAINTENANCE_OUT",
[ MODE_SELECT ] = "MODE_SELECT",
[ RESERVE ] = "RESERVE",
[ RELEASE ] = "RELEASE",
[ COPY ] = "COPY",
[ ERASE ] = "ERASE",
[ MODE_SENSE ] = "MODE_SENSE",
[ START_STOP ] = "START_STOP",
[ RECEIVE_DIAGNOSTIC ] = "RECEIVE_DIAGNOSTIC",
[ SEND_DIAGNOSTIC ] = "SEND_DIAGNOSTIC",
[ ALLOW_MEDIUM_REMOVAL ] = "ALLOW_MEDIUM_REMOVAL",
[ SET_WINDOW ] = "SET_WINDOW",
[ READ_CAPACITY ] = "READ_CAPACITY",
[ READ_10 ] = "READ_10",
[ WRITE_10 ] = "WRITE_10",
[ SEEK_10 ] = "SEEK_10",
[ WRITE_VERIFY ] = "WRITE_VERIFY",
[ VERIFY ] = "VERIFY",
[ SEARCH_HIGH ] = "SEARCH_HIGH",
[ SEARCH_EQUAL ] = "SEARCH_EQUAL",
[ SEARCH_LOW ] = "SEARCH_LOW",
[ SET_LIMITS ] = "SET_LIMITS",
[ PRE_FETCH ] = "PRE_FETCH",
/* READ_POSITION and PRE_FETCH use the same operation code */
[ SYNCHRONIZE_CACHE ] = "SYNCHRONIZE_CACHE",
[ LOCK_UNLOCK_CACHE ] = "LOCK_UNLOCK_CACHE",
[ READ_DEFECT_DATA ] = "READ_DEFECT_DATA",
[ MEDIUM_SCAN ] = "MEDIUM_SCAN",
[ COMPARE ] = "COMPARE",
[ COPY_VERIFY ] = "COPY_VERIFY",
[ WRITE_BUFFER ] = "WRITE_BUFFER",
[ READ_BUFFER ] = "READ_BUFFER",
[ UPDATE_BLOCK ] = "UPDATE_BLOCK",
[ READ_LONG ] = "READ_LONG",
[ WRITE_LONG ] = "WRITE_LONG",
[ CHANGE_DEFINITION ] = "CHANGE_DEFINITION",
[ WRITE_SAME ] = "WRITE_SAME",
[ READ_TOC ] = "READ_TOC",
[ LOG_SELECT ] = "LOG_SELECT",
[ LOG_SENSE ] = "LOG_SENSE",
[ MODE_SELECT_10 ] = "MODE_SELECT_10",
[ RESERVE_10 ] = "RESERVE_10",
[ RELEASE_10 ] = "RELEASE_10",
[ MODE_SENSE_10 ] = "MODE_SENSE_10",
[ PERSISTENT_RESERVE_IN ] = "PERSISTENT_RESERVE_IN",
[ PERSISTENT_RESERVE_OUT ] = "PERSISTENT_RESERVE_OUT",
[ MOVE_MEDIUM ] = "MOVE_MEDIUM",
[ READ_12 ] = "READ_12",
[ WRITE_12 ] = "WRITE_12",
[ WRITE_VERIFY_12 ] = "WRITE_VERIFY_12",
[ SEARCH_HIGH_12 ] = "SEARCH_HIGH_12",
[ SEARCH_EQUAL_12 ] = "SEARCH_EQUAL_12",
[ SEARCH_LOW_12 ] = "SEARCH_LOW_12",
[ READ_ELEMENT_STATUS ] = "READ_ELEMENT_STATUS",
[ SEND_VOLUME_TAG ] = "SEND_VOLUME_TAG",
[ WRITE_LONG_2 ] = "WRITE_LONG_2",
[ REPORT_DENSITY_SUPPORT ] = "REPORT_DENSITY_SUPPORT",
[ GET_CONFIGURATION ] = "GET_CONFIGURATION",
[ READ_16 ] = "READ_16",
[ WRITE_16 ] = "WRITE_16",
[ WRITE_VERIFY_16 ] = "WRITE_VERIFY_16",
[ SERVICE_ACTION_IN ] = "SERVICE_ACTION_IN",
[ REPORT_LUNS ] = "REPORT_LUNS",
[ LOAD_UNLOAD ] = "LOAD_UNLOAD",
[ SET_CD_SPEED ] = "SET_CD_SPEED",
[ BLANK ] = "BLANK",
};
if (cmd >= ARRAY_SIZE(names) || names[cmd] == NULL)
return "*UNKNOWN*";
return names[cmd];
}
SCSIRequest *scsi_req_ref(SCSIRequest *req)
{
req->refcount++;
return req;
}
void scsi_req_unref(SCSIRequest *req)
{
if (--req->refcount == 0) {
if (req->dev->info->free_req) {
req->dev->info->free_req(req);
}
qemu_free(req);
}
}
/* Tell the device that we finished processing this chunk of I/O. It
will start the next chunk or complete the command. */
void scsi_req_continue(SCSIRequest *req)
{
trace_scsi_req_continue(req->dev->id, req->lun, req->tag);
if (req->cmd.mode == SCSI_XFER_TO_DEV) {
req->dev->info->write_data(req);
} else {
req->dev->info->read_data(req);
}
}
/* Called by the devices when data is ready for the HBA. The HBA should
start a DMA operation to read or fill the device's data buffer.
Once it completes, calling scsi_req_continue will restart I/O. */
void scsi_req_data(SCSIRequest *req, int len)
{
trace_scsi_req_data(req->dev->id, req->lun, req->tag, len);
req->bus->ops->transfer_data(req, len);
}
void scsi_req_print(SCSIRequest *req)
{
FILE *fp = stderr;
int i;
fprintf(fp, "[%s id=%d] %s",
req->dev->qdev.parent_bus->name,
req->dev->id,
scsi_command_name(req->cmd.buf[0]));
for (i = 1; i < req->cmd.len; i++) {
fprintf(fp, " 0x%02x", req->cmd.buf[i]);
}
switch (req->cmd.mode) {
case SCSI_XFER_NONE:
fprintf(fp, " - none\n");
break;
case SCSI_XFER_FROM_DEV:
fprintf(fp, " - from-dev len=%zd\n", req->cmd.xfer);
break;
case SCSI_XFER_TO_DEV:
fprintf(fp, " - to-dev len=%zd\n", req->cmd.xfer);
break;
default:
fprintf(fp, " - Oops\n");
break;
}
}
void scsi_req_complete(SCSIRequest *req)
{
assert(req->status != -1);
scsi_req_ref(req);
scsi_req_dequeue(req);
req->bus->ops->complete(req, req->status);
scsi_req_unref(req);
}
void scsi_req_cancel(SCSIRequest *req)
{
if (req->dev && req->dev->info->cancel_io) {
req->dev->info->cancel_io(req);
}
scsi_req_ref(req);
scsi_req_dequeue(req);
if (req->bus->ops->cancel) {
req->bus->ops->cancel(req);
}
scsi_req_unref(req);
}
void scsi_req_abort(SCSIRequest *req, int status)
{
req->status = status;
if (req->dev && req->dev->info->cancel_io) {
req->dev->info->cancel_io(req);
}
scsi_req_complete(req);
}
void scsi_device_purge_requests(SCSIDevice *sdev)
{
SCSIRequest *req;
while (!QTAILQ_EMPTY(&sdev->requests)) {
req = QTAILQ_FIRST(&sdev->requests);
scsi_req_cancel(req);
}
}
static char *scsibus_get_fw_dev_path(DeviceState *dev)
{
SCSIDevice *d = (SCSIDevice*)dev;
SCSIBus *bus = scsi_bus_from_device(d);
char path[100];
int i;
for (i = 0; i < bus->ndev; i++) {
if (bus->devs[i] == d) {
break;
}
}
assert(i != bus->ndev);
snprintf(path, sizeof(path), "%s@%x", qdev_fw_name(dev), i);
return strdup(path);
}