Commit 8ffb1bcf authored by Gerd Hoffmann's avatar Gerd Hoffmann Committed by Anthony Liguori
Browse files

qdev: bus walker + qdev_device_add() 



This patch implements a parser and qdev tree walker for bus paths and
adds qdev_device_add on top of this.

A bus path can be:
  (1) full path, i.e. /i440FX-pcihost/pci.0/lsi/scsi.0
  (2) bus name, i.e. "scsi.0".  Best used together with id= to make
      sure this is unique.
  (3) relative path starting with a bus name, i.e. "pci.0/lsi/scsi.0"

For the (common) case of a single child bus being attached to a device
it is enougth to specify the device only, i.e. "pci.0/lsi" will be
accepted too.

qdev_device_add() adds devices and accepts bus= parameters to find the
bus the device should be attached to.  Without bus= being specified it
takes the first bus it finds where the device can be attached to (i.e.
first pci bus for pci devices, ...).

Signed-off-by: default avatarGerd Hoffmann <kraxel@redhat.com>
Signed-off-by: default avatarAnthony Liguori <aliguori@us.ibm.com>
parent d271de9f

hw/qdev.c

+251 −0
Original line number Diff line number Diff line
@@ -35,6 +35,10 @@ static BusState *main_system_bus; 


static DeviceInfo *device_info_list;



static BusState *qbus_find_recursive(BusState *bus, const char *name,

                                     const BusInfo *info);

static BusState *qbus_find(const char *path);



/* Register a new device type.  */

void qdev_register(DeviceInfo *info)

{
@@ -101,6 +105,80 @@ DeviceState *qdev_create(BusState *bus, const char *name) 
    return dev;

}



DeviceState *qdev_device_add(const char *cmdline)

{

    DeviceInfo *info;

    DeviceState *qdev;

    BusState *bus;

    char driver[32], path[128] = "";

    char tag[32], value[256];

    const char *params = NULL;

    int n = 0;



    if (1 != sscanf(cmdline, "%32[^,],%n", driver, &n)) {

        fprintf(stderr, "device parse error: \"%s\"\n", cmdline);

        return NULL;

    }

    if (strcmp(driver, "?") == 0) {

        for (info = device_info_list; info != NULL; info = info->next) {

            fprintf(stderr, "name \"%s\", bus %s\n", info->name, info->bus_info->name);

        }

        return NULL;

    }

    if (n) {

        params = cmdline + n;

        get_param_value(path, sizeof(path), "bus",  params);

    }

    info = qdev_find_info(NULL, driver);

    if (!info) {

        fprintf(stderr, "Device \"%s\" not found.  Try -device '?' for a list.\n",

                driver);

        return NULL;

    }

    if (info->no_user) {

        fprintf(stderr, "device \"%s\" can't be added via command line\n",

                info->name);

        return NULL;

    }



    if (strlen(path)) {

        bus = qbus_find(path);

        if (!bus)

            return NULL;

        qdev = qdev_create(bus, driver);

    } else {

        bus = qbus_find_recursive(main_system_bus, NULL, info->bus_info);

        if (!bus)

            return NULL;

        qdev = qdev_create(bus, driver);

    }



    if (params) {

        while (params[0]) {

            if (2 != sscanf(params, "%31[^=]=%255[^,]%n", tag, value, &n)) {

                fprintf(stderr, "parse error at \"%s\"\n", params);

                break;

            }

            params += n;

            if (params[0] == ',')

                params++;

            if (strcmp(tag, "bus") == 0)

                continue;

            if (strcmp(tag, "id") == 0) {

                qdev->id = qemu_strdup(value);

                continue;

            }

            if (-1 == qdev_prop_parse(qdev, tag, value)) {

                fprintf(stderr, "can't set property \"%s\" to \"%s\" for \"%s\"\n",

                        tag, value, driver);

            }

        }

    }



    qdev_init(qdev);

    return qdev;

}



/* Initialize a device.  Device properties should be set before calling

   this function.  IRQs and MMIO regions should be connected/mapped after

   calling this function.  */
@@ -229,6 +307,179 @@ void scsi_bus_new(DeviceState *host, SCSIAttachFn attach) 
   }

}



static BusState *qbus_find_recursive(BusState *bus, const char *name,

                                     const BusInfo *info)

{

    DeviceState *dev;

    BusState *child, *ret;

    int match = 1;



    if (name && (strcmp(bus->name, name) != 0)) {

        match = 0;

    }

    if (info && (bus->info != info)) {

        match = 0;

    }

    if (match) {

        return bus;

    }



    LIST_FOREACH(dev, &bus->children, sibling) {

        LIST_FOREACH(child, &dev->child_bus, sibling) {

            ret = qbus_find_recursive(child, name, info);

            if (ret) {

                return ret;

            }

        }

    }

    return NULL;

}



static void qbus_list_bus(DeviceState *dev, char *dest, int len)

{

    BusState *child;

    const char *sep = " ";

    int pos = 0;



    pos += snprintf(dest+pos, len-pos,"child busses at \"%s\":",

                    dev->id ? dev->id : dev->info->name);

    LIST_FOREACH(child, &dev->child_bus, sibling) {

        pos += snprintf(dest+pos, len-pos, "%s\"%s\"", sep, child->name);

        sep = ", ";

    }

}



static void qbus_list_dev(BusState *bus, char *dest, int len)

{

    DeviceState *dev;

    const char *sep = " ";

    int pos = 0;



    pos += snprintf(dest+pos, len-pos, "devices at \"%s\":",

                    bus->name);

    LIST_FOREACH(dev, &bus->children, sibling) {

        pos += snprintf(dest+pos, len-pos, "%s\"%s\"",

                        sep, dev->info->name);

        if (dev->id)

            pos += snprintf(dest+pos, len-pos, "/\"%s\"", dev->id);

        sep = ", ";

    }

}



static BusState *qbus_find_bus(DeviceState *dev, char *elem)

{

    BusState *child;



    LIST_FOREACH(child, &dev->child_bus, sibling) {

        if (strcmp(child->name, elem) == 0) {

            return child;

        }

    }

    return NULL;

}



static DeviceState *qbus_find_dev(BusState *bus, char *elem)

{

    DeviceState *dev;



    /*

     * try to match in order:

     *   (1) instance id, if present

     *   (2) driver name

     *   (3) driver alias, if present

     */

    LIST_FOREACH(dev, &bus->children, sibling) {

        if (dev->id  &&  strcmp(dev->id, elem) == 0) {

            return dev;

        }

    }

    LIST_FOREACH(dev, &bus->children, sibling) {

        if (strcmp(dev->info->name, elem) == 0) {

            return dev;

        }

    }

    LIST_FOREACH(dev, &bus->children, sibling) {

        if (dev->info->alias && strcmp(dev->info->alias, elem) == 0) {

            return dev;

        }

    }

    return NULL;

}



static BusState *qbus_find(const char *path)

{

    DeviceState *dev;

    BusState *bus;

    char elem[128], msg[256];

    int pos, len;



    /* find start element */

    if (path[0] == '/') {

        bus = main_system_bus;

        pos = 0;

    } else {

        if (sscanf(path, "%127[^/]%n", elem, &len) != 1) {

            fprintf(stderr, "path parse error (\"%s\")\n", path);

            return NULL;

        }

        bus = qbus_find_recursive(main_system_bus, elem, NULL);

        if (!bus) {

            fprintf(stderr, "bus \"%s\" not found\n", elem);

            return NULL;

        }

        pos = len;

    }



    for (;;) {

        if (path[pos] == '\0') {

            /* we are done */

            return bus;

        }



        /* find device */

        if (sscanf(path+pos, "/%127[^/]%n", elem, &len) != 1) {

            fprintf(stderr, "path parse error (\"%s\" pos %d)\n", path, pos);

            return NULL;

        }

        pos += len;

        dev = qbus_find_dev(bus, elem);

        if (!dev) {

            qbus_list_dev(bus, msg, sizeof(msg));

            fprintf(stderr, "device \"%s\" not found\n%s\n", elem, msg);

            return NULL;

        }

        if (path[pos] == '\0') {

            /* last specified element is a device.  If it has exactly

             * one child bus accept it nevertheless */

            switch (dev->num_child_bus) {

            case 0:

                fprintf(stderr, "device has no child bus (%s)\n", path);

                return NULL;

            case 1:

                return LIST_FIRST(&dev->child_bus);

            default:

                qbus_list_bus(dev, msg, sizeof(msg));

                fprintf(stderr, "device has multiple child busses (%s)\n%s\n",

                        path, msg);

                return NULL;

            }

        }



        /* find bus */

        if (sscanf(path+pos, "/%127[^/]%n", elem, &len) != 1) {

            fprintf(stderr, "path parse error (\"%s\" pos %d)\n", path, pos);

            return NULL;

        }

        pos += len;

        bus = qbus_find_bus(dev, elem);

        if (!bus) {

            qbus_list_bus(dev, msg, sizeof(msg));

            fprintf(stderr, "child bus \"%s\" not found\n%s\n", elem, msg);

            return NULL;

        }

    }

}



BusState *qbus_create(BusInfo *info, DeviceState *parent, const char *name)

{

    BusState *bus;

hw/qdev.h

+1 −0
Original line number Diff line number Diff line
@@ -82,6 +82,7 @@ struct CompatProperty { 
/*** Board API.  This should go away once we have a machine config file.  ***/



DeviceState *qdev_create(BusState *bus, const char *name);

DeviceState *qdev_device_add(const char *cmdline);

void qdev_init(DeviceState *dev);

void qdev_free(DeviceState *dev);