diff options
Diffstat (limited to 'hw/block/xen-block.c')
| -rw-r--r-- | hw/block/xen-block.c | 1024 |
1 files changed, 1024 insertions, 0 deletions
diff --git a/hw/block/xen-block.c b/hw/block/xen-block.c new file mode 100644 index 000000000..674953f1a --- /dev/null +++ b/hw/block/xen-block.c @@ -0,0 +1,1024 @@ +/* + * Copyright (c) 2018 Citrix Systems Inc. + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ + +#include "qemu/osdep.h" +#include "qemu/cutils.h" +#include "qemu/main-loop.h" +#include "qemu/module.h" +#include "qemu/option.h" +#include "qapi/error.h" +#include "qapi/qapi-commands-block-core.h" +#include "qapi/qapi-commands-qom.h" +#include "qapi/qapi-visit-block-core.h" +#include "qapi/qobject-input-visitor.h" +#include "qapi/visitor.h" +#include "qapi/qmp/qdict.h" +#include "qapi/qmp/qstring.h" +#include "qom/object_interfaces.h" +#include "hw/xen/xen_common.h" +#include "hw/block/xen_blkif.h" +#include "hw/qdev-properties.h" +#include "hw/xen/xen-block.h" +#include "hw/xen/xen-backend.h" +#include "sysemu/blockdev.h" +#include "sysemu/block-backend.h" +#include "sysemu/iothread.h" +#include "dataplane/xen-block.h" +#include "trace.h" + +static char *xen_block_get_name(XenDevice *xendev, Error **errp) +{ + XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev); + XenBlockVdev *vdev = &blockdev->props.vdev; + + return g_strdup_printf("%lu", vdev->number); +} + +static void xen_block_disconnect(XenDevice *xendev, Error **errp) +{ + XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev); + const char *type = object_get_typename(OBJECT(blockdev)); + XenBlockVdev *vdev = &blockdev->props.vdev; + + trace_xen_block_disconnect(type, vdev->disk, vdev->partition); + + xen_block_dataplane_stop(blockdev->dataplane); +} + +static void xen_block_connect(XenDevice *xendev, Error **errp) +{ + XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev); + const char *type = object_get_typename(OBJECT(blockdev)); + XenBlockVdev *vdev = &blockdev->props.vdev; + BlockConf *conf = &blockdev->props.conf; + unsigned int feature_large_sector_size; + unsigned int order, nr_ring_ref, *ring_ref, event_channel, protocol; + char *str; + + trace_xen_block_connect(type, vdev->disk, vdev->partition); + + if (xen_device_frontend_scanf(xendev, "feature-large-sector-size", "%u", + &feature_large_sector_size) != 1) { + feature_large_sector_size = 0; + } + + if (feature_large_sector_size != 1 && + conf->logical_block_size != XEN_BLKIF_SECTOR_SIZE) { + error_setg(errp, "logical_block_size != %u not supported by frontend", + XEN_BLKIF_SECTOR_SIZE); + return; + } + + if (xen_device_frontend_scanf(xendev, "ring-page-order", "%u", + &order) != 1) { + nr_ring_ref = 1; + ring_ref = g_new(unsigned int, nr_ring_ref); + + if (xen_device_frontend_scanf(xendev, "ring-ref", "%u", + &ring_ref[0]) != 1) { + error_setg(errp, "failed to read ring-ref"); + g_free(ring_ref); + return; + } + } else if (order <= blockdev->props.max_ring_page_order) { + unsigned int i; + + nr_ring_ref = 1 << order; + ring_ref = g_new(unsigned int, nr_ring_ref); + + for (i = 0; i < nr_ring_ref; i++) { + const char *key = g_strdup_printf("ring-ref%u", i); + + if (xen_device_frontend_scanf(xendev, key, "%u", + &ring_ref[i]) != 1) { + error_setg(errp, "failed to read %s", key); + g_free((gpointer)key); + g_free(ring_ref); + return; + } + + g_free((gpointer)key); + } + } else { + error_setg(errp, "invalid ring-page-order (%d)", order); + return; + } + + if (xen_device_frontend_scanf(xendev, "event-channel", "%u", + &event_channel) != 1) { + error_setg(errp, "failed to read event-channel"); + g_free(ring_ref); + return; + } + + if (xen_device_frontend_scanf(xendev, "protocol", "%ms", + &str) != 1) { + protocol = BLKIF_PROTOCOL_NATIVE; + } else { + if (strcmp(str, XEN_IO_PROTO_ABI_X86_32) == 0) { + protocol = BLKIF_PROTOCOL_X86_32; + } else if (strcmp(str, XEN_IO_PROTO_ABI_X86_64) == 0) { + protocol = BLKIF_PROTOCOL_X86_64; + } else { + protocol = BLKIF_PROTOCOL_NATIVE; + } + + free(str); + } + + xen_block_dataplane_start(blockdev->dataplane, ring_ref, nr_ring_ref, + event_channel, protocol, errp); + + g_free(ring_ref); +} + +static void xen_block_unrealize(XenDevice *xendev) +{ + XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev); + XenBlockDeviceClass *blockdev_class = + XEN_BLOCK_DEVICE_GET_CLASS(xendev); + const char *type = object_get_typename(OBJECT(blockdev)); + XenBlockVdev *vdev = &blockdev->props.vdev; + + if (vdev->type == XEN_BLOCK_VDEV_TYPE_INVALID) { + return; + } + + trace_xen_block_unrealize(type, vdev->disk, vdev->partition); + + /* Disconnect from the frontend in case this has not already happened */ + xen_block_disconnect(xendev, NULL); + + xen_block_dataplane_destroy(blockdev->dataplane); + blockdev->dataplane = NULL; + + if (blockdev_class->unrealize) { + blockdev_class->unrealize(blockdev); + } +} + +static void xen_block_set_size(XenBlockDevice *blockdev) +{ + const char *type = object_get_typename(OBJECT(blockdev)); + XenBlockVdev *vdev = &blockdev->props.vdev; + BlockConf *conf = &blockdev->props.conf; + int64_t sectors = blk_getlength(conf->blk) / conf->logical_block_size; + XenDevice *xendev = XEN_DEVICE(blockdev); + + trace_xen_block_size(type, vdev->disk, vdev->partition, sectors); + + xen_device_backend_printf(xendev, "sectors", "%"PRIi64, sectors); +} + +static void xen_block_resize_cb(void *opaque) +{ + XenBlockDevice *blockdev = opaque; + XenDevice *xendev = XEN_DEVICE(blockdev); + enum xenbus_state state = xen_device_backend_get_state(xendev); + + xen_block_set_size(blockdev); + + /* + * Mimic the behaviour of Linux xen-blkback and re-write the state + * to trigger the frontend watch. + */ + xen_device_backend_printf(xendev, "state", "%u", state); +} + +static const BlockDevOps xen_block_dev_ops = { + .resize_cb = xen_block_resize_cb, +}; + +static void xen_block_realize(XenDevice *xendev, Error **errp) +{ + ERRP_GUARD(); + XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev); + XenBlockDeviceClass *blockdev_class = + XEN_BLOCK_DEVICE_GET_CLASS(xendev); + const char *type = object_get_typename(OBJECT(blockdev)); + XenBlockVdev *vdev = &blockdev->props.vdev; + BlockConf *conf = &blockdev->props.conf; + BlockBackend *blk = conf->blk; + + if (vdev->type == XEN_BLOCK_VDEV_TYPE_INVALID) { + error_setg(errp, "vdev property not set"); + return; + } + + trace_xen_block_realize(type, vdev->disk, vdev->partition); + + if (blockdev_class->realize) { + blockdev_class->realize(blockdev, errp); + if (*errp) { + return; + } + } + + /* + * The blkif protocol does not deal with removable media, so it must + * always be present, even for CDRom devices. + */ + assert(blk); + if (!blk_is_inserted(blk)) { + error_setg(errp, "device needs media, but drive is empty"); + return; + } + + if (!blkconf_apply_backend_options(conf, blockdev->info & VDISK_READONLY, + true, errp)) { + return; + } + + if (!(blockdev->info & VDISK_CDROM) && + !blkconf_geometry(conf, NULL, 65535, 255, 255, errp)) { + return; + } + + if (!blkconf_blocksizes(conf, errp)) { + return; + } + + blk_set_dev_ops(blk, &xen_block_dev_ops, blockdev); + blk_set_guest_block_size(blk, conf->logical_block_size); + + if (conf->discard_granularity == -1) { + conf->discard_granularity = conf->physical_block_size; + } + + if (blk_get_flags(blk) & BDRV_O_UNMAP) { + xen_device_backend_printf(xendev, "feature-discard", "%u", 1); + xen_device_backend_printf(xendev, "discard-granularity", "%u", + conf->discard_granularity); + xen_device_backend_printf(xendev, "discard-alignment", "%u", 0); + } + + xen_device_backend_printf(xendev, "feature-flush-cache", "%u", 1); + xen_device_backend_printf(xendev, "max-ring-page-order", "%u", + blockdev->props.max_ring_page_order); + xen_device_backend_printf(xendev, "info", "%u", blockdev->info); + + xen_device_frontend_printf(xendev, "virtual-device", "%lu", + vdev->number); + xen_device_frontend_printf(xendev, "device-type", "%s", + blockdev->device_type); + + xen_device_backend_printf(xendev, "sector-size", "%u", + conf->logical_block_size); + + xen_block_set_size(blockdev); + + blockdev->dataplane = + xen_block_dataplane_create(xendev, blk, conf->logical_block_size, + blockdev->props.iothread); +} + +static void xen_block_frontend_changed(XenDevice *xendev, + enum xenbus_state frontend_state, + Error **errp) +{ + ERRP_GUARD(); + enum xenbus_state backend_state = xen_device_backend_get_state(xendev); + + switch (frontend_state) { + case XenbusStateInitialised: + case XenbusStateConnected: + if (backend_state == XenbusStateConnected) { + break; + } + + xen_block_disconnect(xendev, errp); + if (*errp) { + break; + } + + xen_block_connect(xendev, errp); + if (*errp) { + break; + } + + xen_device_backend_set_state(xendev, XenbusStateConnected); + break; + + case XenbusStateClosing: + xen_device_backend_set_state(xendev, XenbusStateClosing); + break; + + case XenbusStateClosed: + case XenbusStateUnknown: + xen_block_disconnect(xendev, errp); + if (*errp) { + break; + } + + xen_device_backend_set_state(xendev, XenbusStateClosed); + break; + + default: + break; + } +} + +static char *disk_to_vbd_name(unsigned int disk) +{ + char *name, *prefix = (disk >= 26) ? + disk_to_vbd_name((disk / 26) - 1) : g_strdup(""); + + name = g_strdup_printf("%s%c", prefix, 'a' + disk % 26); + g_free(prefix); + + return name; +} + +static void xen_block_get_vdev(Object *obj, Visitor *v, const char *name, + void *opaque, Error **errp) +{ + Property *prop = opaque; + XenBlockVdev *vdev = object_field_prop_ptr(obj, prop); + char *str; + + switch (vdev->type) { + case XEN_BLOCK_VDEV_TYPE_DP: + str = g_strdup_printf("d%lup%lu", vdev->disk, vdev->partition); + break; + + case XEN_BLOCK_VDEV_TYPE_XVD: + case XEN_BLOCK_VDEV_TYPE_HD: + case XEN_BLOCK_VDEV_TYPE_SD: { + char *name = disk_to_vbd_name(vdev->disk); + + str = g_strdup_printf("%s%s%lu", + (vdev->type == XEN_BLOCK_VDEV_TYPE_XVD) ? + "xvd" : + (vdev->type == XEN_BLOCK_VDEV_TYPE_HD) ? + "hd" : + "sd", + name, vdev->partition); + g_free(name); + break; + } + default: + error_setg(errp, "invalid vdev type"); + return; + } + + visit_type_str(v, name, &str, errp); + g_free(str); +} + +static int vbd_name_to_disk(const char *name, const char **endp, + unsigned long *disk) +{ + unsigned int n = 0; + + while (*name != '\0') { + if (!g_ascii_isalpha(*name) || !g_ascii_islower(*name)) { + break; + } + + n *= 26; + n += *name++ - 'a' + 1; + } + *endp = name; + + if (!n) { + return -1; + } + + *disk = n - 1; + + return 0; +} + +static void xen_block_set_vdev(Object *obj, Visitor *v, const char *name, + void *opaque, Error **errp) +{ + Property *prop = opaque; + XenBlockVdev *vdev = object_field_prop_ptr(obj, prop); + char *str, *p; + const char *end; + + if (!visit_type_str(v, name, &str, errp)) { + return; + } + + p = strchr(str, 'd'); + if (!p) { + goto invalid; + } + + *p++ = '\0'; + if (*str == '\0') { + vdev->type = XEN_BLOCK_VDEV_TYPE_DP; + } else if (strcmp(str, "xv") == 0) { + vdev->type = XEN_BLOCK_VDEV_TYPE_XVD; + } else if (strcmp(str, "h") == 0) { + vdev->type = XEN_BLOCK_VDEV_TYPE_HD; + } else if (strcmp(str, "s") == 0) { + vdev->type = XEN_BLOCK_VDEV_TYPE_SD; + } else { + goto invalid; + } + + if (vdev->type == XEN_BLOCK_VDEV_TYPE_DP) { + if (qemu_strtoul(p, &end, 10, &vdev->disk)) { + goto invalid; + } + + if (*end == 'p') { + if (*(++end) == '\0') { + goto invalid; + } + } + } else { + if (vbd_name_to_disk(p, &end, &vdev->disk)) { + goto invalid; + } + } + + if (*end != '\0') { + p = (char *)end; + + if (qemu_strtoul(p, &end, 10, &vdev->partition)) { + goto invalid; + } + + if (*end != '\0') { + goto invalid; + } + } else { + vdev->partition = 0; + } + + switch (vdev->type) { + case XEN_BLOCK_VDEV_TYPE_DP: + case XEN_BLOCK_VDEV_TYPE_XVD: + if (vdev->disk < (1 << 4) && vdev->partition < (1 << 4)) { + vdev->number = (202 << 8) | (vdev->disk << 4) | + vdev->partition; + } else if (vdev->disk < (1 << 20) && vdev->partition < (1 << 8)) { + vdev->number = (1 << 28) | (vdev->disk << 8) | + vdev->partition; + } else { + goto invalid; + } + break; + + case XEN_BLOCK_VDEV_TYPE_HD: + if ((vdev->disk == 0 || vdev->disk == 1) && + vdev->partition < (1 << 6)) { + vdev->number = (3 << 8) | (vdev->disk << 6) | vdev->partition; + } else if ((vdev->disk == 2 || vdev->disk == 3) && + vdev->partition < (1 << 6)) { + vdev->number = (22 << 8) | ((vdev->disk - 2) << 6) | + vdev->partition; + } else { + goto invalid; + } + break; + + case XEN_BLOCK_VDEV_TYPE_SD: + if (vdev->disk < (1 << 4) && vdev->partition < (1 << 4)) { + vdev->number = (8 << 8) | (vdev->disk << 4) | vdev->partition; + } else { + goto invalid; + } + break; + + default: + goto invalid; + } + + g_free(str); + return; + +invalid: + error_setg(errp, "invalid virtual disk specifier"); + + vdev->type = XEN_BLOCK_VDEV_TYPE_INVALID; + g_free(str); +} + +/* + * This property deals with 'vdev' names adhering to the Xen VBD naming + * scheme described in: + * + * https://xenbits.xen.org/docs/unstable/man/xen-vbd-interface.7.html + */ +const PropertyInfo xen_block_prop_vdev = { + .name = "str", + .description = "Virtual Disk specifier: d*p*/xvd*/hd*/sd*", + .get = xen_block_get_vdev, + .set = xen_block_set_vdev, +}; + +static Property xen_block_props[] = { + DEFINE_PROP("vdev", XenBlockDevice, props.vdev, + xen_block_prop_vdev, XenBlockVdev), + DEFINE_BLOCK_PROPERTIES(XenBlockDevice, props.conf), + DEFINE_PROP_UINT32("max-ring-page-order", XenBlockDevice, + props.max_ring_page_order, 4), + DEFINE_PROP_LINK("iothread", XenBlockDevice, props.iothread, + TYPE_IOTHREAD, IOThread *), + DEFINE_PROP_END_OF_LIST() +}; + +static void xen_block_class_init(ObjectClass *class, void *data) +{ + DeviceClass *dev_class = DEVICE_CLASS(class); + XenDeviceClass *xendev_class = XEN_DEVICE_CLASS(class); + + xendev_class->backend = "qdisk"; + xendev_class->device = "vbd"; + xendev_class->get_name = xen_block_get_name; + xendev_class->realize = xen_block_realize; + xendev_class->frontend_changed = xen_block_frontend_changed; + xendev_class->unrealize = xen_block_unrealize; + + device_class_set_props(dev_class, xen_block_props); +} + +static const TypeInfo xen_block_type_info = { + .name = TYPE_XEN_BLOCK_DEVICE, + .parent = TYPE_XEN_DEVICE, + .instance_size = sizeof(XenBlockDevice), + .abstract = true, + .class_size = sizeof(XenBlockDeviceClass), + .class_init = xen_block_class_init, +}; + +static void xen_disk_unrealize(XenBlockDevice *blockdev) +{ + trace_xen_disk_unrealize(); +} + +static void xen_disk_realize(XenBlockDevice *blockdev, Error **errp) +{ + BlockConf *conf = &blockdev->props.conf; + + trace_xen_disk_realize(); + + blockdev->device_type = "disk"; + + if (!conf->blk) { + error_setg(errp, "drive property not set"); + return; + } + + blockdev->info = blk_supports_write_perm(conf->blk) ? 0 : VDISK_READONLY; +} + +static void xen_disk_class_init(ObjectClass *class, void *data) +{ + DeviceClass *dev_class = DEVICE_CLASS(class); + XenBlockDeviceClass *blockdev_class = XEN_BLOCK_DEVICE_CLASS(class); + + blockdev_class->realize = xen_disk_realize; + blockdev_class->unrealize = xen_disk_unrealize; + + dev_class->desc = "Xen Disk Device"; +} + +static const TypeInfo xen_disk_type_info = { + .name = TYPE_XEN_DISK_DEVICE, + .parent = TYPE_XEN_BLOCK_DEVICE, + .instance_size = sizeof(XenDiskDevice), + .class_init = xen_disk_class_init, +}; + +static void xen_cdrom_unrealize(XenBlockDevice *blockdev) +{ + trace_xen_cdrom_unrealize(); +} + +static void xen_cdrom_realize(XenBlockDevice *blockdev, Error **errp) +{ + BlockConf *conf = &blockdev->props.conf; + + trace_xen_cdrom_realize(); + + blockdev->device_type = "cdrom"; + + if (!conf->blk) { + int rc; + + /* Set up an empty drive */ + conf->blk = blk_new(qemu_get_aio_context(), 0, BLK_PERM_ALL); + + rc = blk_attach_dev(conf->blk, DEVICE(blockdev)); + if (!rc) { + error_setg_errno(errp, -rc, "failed to create drive"); + return; + } + } + + blockdev->info = VDISK_READONLY | VDISK_CDROM; +} + +static void xen_cdrom_class_init(ObjectClass *class, void *data) +{ + DeviceClass *dev_class = DEVICE_CLASS(class); + XenBlockDeviceClass *blockdev_class = XEN_BLOCK_DEVICE_CLASS(class); + + blockdev_class->realize = xen_cdrom_realize; + blockdev_class->unrealize = xen_cdrom_unrealize; + + dev_class->desc = "Xen CD-ROM Device"; +} + +static const TypeInfo xen_cdrom_type_info = { + .name = TYPE_XEN_CDROM_DEVICE, + .parent = TYPE_XEN_BLOCK_DEVICE, + .instance_size = sizeof(XenCDRomDevice), + .class_init = xen_cdrom_class_init, +}; + +static void xen_block_register_types(void) +{ + type_register_static(&xen_block_type_info); + type_register_static(&xen_disk_type_info); + type_register_static(&xen_cdrom_type_info); +} + +type_init(xen_block_register_types) + +static void xen_block_blockdev_del(const char *node_name, Error **errp) +{ + trace_xen_block_blockdev_del(node_name); + + qmp_blockdev_del(node_name, errp); +} + +static char *xen_block_blockdev_add(const char *id, QDict *qdict, + Error **errp) +{ + ERRP_GUARD(); + const char *driver = qdict_get_try_str(qdict, "driver"); + BlockdevOptions *options = NULL; + char *node_name; + Visitor *v; + + if (!driver) { + error_setg(errp, "no 'driver' parameter"); + return NULL; + } + + node_name = g_strdup_printf("%s-%s", id, driver); + qdict_put_str(qdict, "node-name", node_name); + + trace_xen_block_blockdev_add(node_name); + + v = qobject_input_visitor_new(QOBJECT(qdict)); + visit_type_BlockdevOptions(v, NULL, &options, errp); + visit_free(v); + if (!options) { + goto fail; + } + + qmp_blockdev_add(options, errp); + + if (*errp) { + goto fail; + } + + qapi_free_BlockdevOptions(options); + + return node_name; + +fail: + if (options) { + qapi_free_BlockdevOptions(options); + } + g_free(node_name); + + return NULL; +} + +static void xen_block_drive_destroy(XenBlockDrive *drive, Error **errp) +{ + ERRP_GUARD(); + char *node_name = drive->node_name; + + if (node_name) { + xen_block_blockdev_del(node_name, errp); + if (*errp) { + return; + } + g_free(node_name); + drive->node_name = NULL; + } + g_free(drive->id); + g_free(drive); +} + +static XenBlockDrive *xen_block_drive_create(const char *id, + const char *device_type, + QDict *opts, Error **errp) +{ + ERRP_GUARD(); + const char *params = qdict_get_try_str(opts, "params"); + const char *mode = qdict_get_try_str(opts, "mode"); + const char *direct_io_safe = qdict_get_try_str(opts, "direct-io-safe"); + const char *discard_enable = qdict_get_try_str(opts, "discard-enable"); + char *driver = NULL; + char *filename = NULL; + XenBlockDrive *drive = NULL; + QDict *file_layer; + QDict *driver_layer; + struct stat st; + int rc; + + if (params) { + char **v = g_strsplit(params, ":", 2); + + if (v[1] == NULL) { + filename = g_strdup(v[0]); + driver = g_strdup("raw"); + } else { + if (strcmp(v[0], "aio") == 0) { + driver = g_strdup("raw"); + } else if (strcmp(v[0], "vhd") == 0) { + driver = g_strdup("vpc"); + } else { + driver = g_strdup(v[0]); + } + filename = g_strdup(v[1]); + } + + g_strfreev(v); + } else { + error_setg(errp, "no params"); + goto done; + } + + assert(filename); + assert(driver); + + drive = g_new0(XenBlockDrive, 1); + drive->id = g_strdup(id); + + file_layer = qdict_new(); + driver_layer = qdict_new(); + + rc = stat(filename, &st); + if (rc) { + error_setg_errno(errp, errno, "Could not stat file '%s'", filename); + goto done; + } + if (S_ISBLK(st.st_mode)) { + qdict_put_str(file_layer, "driver", "host_device"); + } else { + qdict_put_str(file_layer, "driver", "file"); + } + + qdict_put_str(file_layer, "filename", filename); + g_free(filename); + + if (mode && *mode != 'w') { + qdict_put_bool(file_layer, "read-only", true); + } + + if (direct_io_safe) { + unsigned long value; + + if (!qemu_strtoul(direct_io_safe, NULL, 2, &value) && !!value) { + QDict *cache_qdict = qdict_new(); + + qdict_put_bool(cache_qdict, "direct", true); + qdict_put(file_layer, "cache", cache_qdict); + + qdict_put_str(file_layer, "aio", "native"); + } + } + + if (discard_enable) { + unsigned long value; + + if (!qemu_strtoul(discard_enable, NULL, 2, &value) && !!value) { + qdict_put_str(file_layer, "discard", "unmap"); + qdict_put_str(driver_layer, "discard", "unmap"); + } + } + + /* + * It is necessary to turn file locking off as an emulated device + * may have already opened the same image file. + */ + qdict_put_str(file_layer, "locking", "off"); + + qdict_put_str(driver_layer, "driver", driver); + g_free(driver); + + qdict_put(driver_layer, "file", file_layer); + + g_assert(!drive->node_name); + drive->node_name = xen_block_blockdev_add(drive->id, driver_layer, + errp); + + qobject_unref(driver_layer); + +done: + if (*errp) { + xen_block_drive_destroy(drive, NULL); + return NULL; + } + + return drive; +} + +static const char *xen_block_drive_get_node_name(XenBlockDrive *drive) +{ + return drive->node_name ? drive->node_name : ""; +} + +static void xen_block_iothread_destroy(XenBlockIOThread *iothread, + Error **errp) +{ + qmp_object_del(iothread->id, errp); + + g_free(iothread->id); + g_free(iothread); +} + +static XenBlockIOThread *xen_block_iothread_create(const char *id, + Error **errp) +{ + ERRP_GUARD(); + XenBlockIOThread *iothread = g_new(XenBlockIOThread, 1); + ObjectOptions *opts; + + iothread->id = g_strdup(id); + + opts = g_new(ObjectOptions, 1); + *opts = (ObjectOptions) { + .qom_type = OBJECT_TYPE_IOTHREAD, + .id = g_strdup(id), + }; + qmp_object_add(opts, errp); + qapi_free_ObjectOptions(opts); + + if (*errp) { + g_free(iothread->id); + g_free(iothread); + return NULL; + } + + return iothread; +} + +static void xen_block_device_create(XenBackendInstance *backend, + QDict *opts, Error **errp) +{ + ERRP_GUARD(); + XenBus *xenbus = xen_backend_get_bus(backend); + const char *name = xen_backend_get_name(backend); + unsigned long number; + const char *vdev, *device_type; + XenBlockDrive *drive = NULL; + XenBlockIOThread *iothread = NULL; + XenDevice *xendev = NULL; + const char *type; + XenBlockDevice *blockdev; + + if (qemu_strtoul(name, NULL, 10, &number)) { + error_setg(errp, "failed to parse name '%s'", name); + goto fail; + } + + trace_xen_block_device_create(number); + + vdev = qdict_get_try_str(opts, "dev"); + if (!vdev) { + error_setg(errp, "no dev parameter"); + goto fail; + } + + device_type = qdict_get_try_str(opts, "device-type"); + if (!device_type) { + error_setg(errp, "no device-type parameter"); + goto fail; + } + + if (!strcmp(device_type, "disk")) { + type = TYPE_XEN_DISK_DEVICE; + } else if (!strcmp(device_type, "cdrom")) { + type = TYPE_XEN_CDROM_DEVICE; + } else { + error_setg(errp, "invalid device-type parameter '%s'", device_type); + goto fail; + } + + drive = xen_block_drive_create(vdev, device_type, opts, errp); + if (!drive) { + error_prepend(errp, "failed to create drive: "); + goto fail; + } + + iothread = xen_block_iothread_create(vdev, errp); + if (*errp) { + error_prepend(errp, "failed to create iothread: "); + goto fail; + } + + xendev = XEN_DEVICE(qdev_new(type)); + blockdev = XEN_BLOCK_DEVICE(xendev); + + if (!object_property_set_str(OBJECT(xendev), "vdev", vdev, + errp)) { + error_prepend(errp, "failed to set 'vdev': "); + goto fail; + } + + if (!object_property_set_str(OBJECT(xendev), "drive", + xen_block_drive_get_node_name(drive), + errp)) { + error_prepend(errp, "failed to set 'drive': "); + goto fail; + } + + if (!object_property_set_str(OBJECT(xendev), "iothread", iothread->id, + errp)) { + error_prepend(errp, "failed to set 'iothread': "); + goto fail; + } + + blockdev->iothread = iothread; + blockdev->drive = drive; + + if (!qdev_realize_and_unref(DEVICE(xendev), BUS(xenbus), errp)) { + error_prepend(errp, "realization of device %s failed: ", type); + goto fail; + } + + xen_backend_set_device(backend, xendev); + return; + +fail: + if (xendev) { + object_unparent(OBJECT(xendev)); + } + + if (iothread) { + xen_block_iothread_destroy(iothread, NULL); + } + + if (drive) { + xen_block_drive_destroy(drive, NULL); + } +} + +static void xen_block_device_destroy(XenBackendInstance *backend, + Error **errp) +{ + ERRP_GUARD(); + XenDevice *xendev = xen_backend_get_device(backend); + XenBlockDevice *blockdev = XEN_BLOCK_DEVICE(xendev); + XenBlockVdev *vdev = &blockdev->props.vdev; + XenBlockDrive *drive = blockdev->drive; + XenBlockIOThread *iothread = blockdev->iothread; + + trace_xen_block_device_destroy(vdev->number); + + object_unparent(OBJECT(xendev)); + + /* + * Drain all pending RCU callbacks as object_unparent() frees `xendev' + * in a RCU callback. + * And due to the property "drive" still existing in `xendev', we + * can't destroy the XenBlockDrive associated with `xendev' with + * xen_block_drive_destroy() below. + */ + drain_call_rcu(); + + if (iothread) { + xen_block_iothread_destroy(iothread, errp); + if (*errp) { + error_prepend(errp, "failed to destroy iothread: "); + return; + } + } + + if (drive) { + xen_block_drive_destroy(drive, errp); + if (*errp) { + error_prepend(errp, "failed to destroy drive: "); + return; + } + } +} + +static const XenBackendInfo xen_block_backend_info = { + .type = "qdisk", + .create = xen_block_device_create, + .destroy = xen_block_device_destroy, +}; + +static void xen_block_register_backend(void) +{ + xen_backend_register(&xen_block_backend_info); +} + +xen_backend_init(xen_block_register_backend); |