Re: [Qemu-devel] [PATCH 18/18] blockdev: 'blockdev-add' QMP command

[Wenchao Xia <xiawenc@linux.vnet.ibm.com>]

于 2013-7-23 21:03, Kevin Wolf 写道:
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>   blockdev.c       |  45 +++++++++
>   qapi-schema.json | 293 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
>   qmp-commands.hx  |  26 +++++
>   3 files changed, 364 insertions(+)
> 
> diff --git a/blockdev.c b/blockdev.c
> index ef55b1a..214173b 100644
> --- a/blockdev.c
> +++ b/blockdev.c
> @@ -38,6 +38,8 @@
>   #include "qemu/option.h"
>   #include "qemu/config-file.h"
>   #include "qapi/qmp/types.h"
> +#include "qapi-visit.h"
> +#include "qapi/qmp-output-visitor.h"
>   #include "sysemu/sysemu.h"
>   #include "block/block_int.h"
>   #include "qmp-commands.h"
> @@ -1805,6 +1807,49 @@ void qmp_block_job_complete(const char *device, Error **errp)
>       block_job_complete(job, errp);
>   }
> 
> +void qmp_blockdev_add(BlockdevOptions *options, Error **errp)
> +{
> +    QmpOutputVisitor *ov = qmp_output_visitor_new();
> +    QObject *obj;
> +    QDict *qdict;
> +
> +    if (!options->has_id) {
> +        error_setg(errp, "Block device needs an ID");
> +        return;
> +    }
> +
> +    /* TODO Sort it out in raw-posix and drive_init: Reject aio=native with
> +     * cache.direct=off instead of silently switching to aio=threads, except if
> +     * called from drive_init.
> +     *
> +     * For now, simply forbidding the combination for all drivers will do. */
> +    if (options->has_aio && options->aio == BLOCKDEV_A_I_O_OPTIONS_NATIVE) {
> +        if (!options->has_cache || !options->cache->direct) {
> +            error_setg(errp, "aio=native requires cache.direct=true");
> +            return;
> +        }
> +    }
> +
> +    visit_type_BlockdevOptions(qmp_output_get_visitor(ov),
> +                               &options, NULL, errp);
> +    obj = qmp_output_get_qobject(ov);
> +    qdict = qobject_to_qdict(obj);
> +
> +    qdict_flatten(qdict);
> +
> +    Error *local_err = NULL;
> +    QemuOpts *opts = qemu_opts_from_qdict(&qemu_drive_opts, qdict, &local_err);
> +    if (error_is_set(&local_err)) {
> +        qerror_report_err(local_err);
> +        error_free(local_err);
> +    } else {
> +        blockdev_init(opts, IF_NONE);
> +    }
> +
> +    qobject_decref(obj);
> +    qmp_output_visitor_cleanup(ov);
> +}
> +
>   static void do_qmp_query_block_jobs_one(void *opaque, BlockDriverState *bs)
>   {
>       BlockJobInfoList **prev = opaque;
> diff --git a/qapi-schema.json b/qapi-schema.json
> index 592bb9c..bfe6d32 100644
> --- a/qapi-schema.json
> +++ b/qapi-schema.json
> @@ -3761,3 +3761,296 @@
>   ##
>   { 'command': 'query-rx-filter', 'data': { '*name': 'str' },
>     'returns': ['RxFilterInfo'] }
> +
> +
> +##
> +# @BlockdevDiscardOptions
> +#
> +# Determines how to handle discard requests.
> +#
> +# @ignore:      Ignore the request
> +# @unmap:       Forward as an unmap request
> +#
> +# Since: 1.6
> +##
> +{ 'enum': 'BlockdevDiscardOptions',
> +  'data': [ 'ignore', 'unmap' ] }
> +
> +##
> +# @BlockdevDiscardOptions
> +#
> +# Selects the AIO backend to handle I/O requests
> +#
> +# @threads:     Use qemu's thread pool
> +# @native:      Use native AIO backend (only Linux and Windows)
> +#
> +# Since: 1.6
> +##
> +{ 'enum': 'BlockdevAIOOptions',
> +  'data': [ 'threads', 'native' ] }
> +
> +##
> +# @BlockdevCacheOptions
> +#
> +# Includes cache-related options for block devices
> +#
> +# @writeback:   enables writeback mode for any caches (default: true)
> +# @direct:      enables use of O_DIRECT (bypass the host page cache;
> +#               default: false)
> +# @no-flush:    ignore any flush requests for the device (default: false)
> +#
> +# Since: 1.6
> +##
> +{ 'type': 'BlockdevCacheOptions',
> +  'data': { '*writeback': 'bool',
> +            '*direct': 'bool',
> +            '*no-flush': 'bool' } }
> +
> +##
> +# @BlockdevThrottlingOptions
> +#
> +# Includes block device options related to I/O throttling. Leaving an option out
> +# means the same as assigning 0 and applies no throttling.
> +#
> +# @bps-total:   limit total bytes per second
> +# @bps-read:    limit read bytes per second
> +# @bps-write:   limit written bytes per second
> +# @iops-total:  limit total I/O operations per second
> +# @iops-read:   limit read operations per second
> +# @iops-write:  limit write operations per second
> +#
> +# Since: 1.6
> +##
> +{ 'type': 'BlockdevThrottlingOptions',
> +  'data': { '*bps-total': 'int',
> +            '*bps-read': 'int',
> +            '*bps-write': 'int',
> +            '*iops-total': 'int',
> +            '*iops-read': 'int',
> +            '*iops-write': 'int' } }
> +
> +##
> +# @BlockdevOptionsBase
> +#
> +# Options that are available for all block devices, independent of the block
> +# driver.
> +#
> +# @driver:      block driver name
> +# @id:          id by which the new block device can be referred to
> +# @discard:     discard-related options
> +# @cache:       cache-related options
> +# @aio:         AIO backend (default: threads)
> +# @rerror:      how to handle read errors on the device (default: report)
> +# @werror:      how to handle write errors on the device (default: enospc)
> +# @throttling:  I/O throttling related options
> +# @read-only:   whether the block device should be read-only (default: false)
> +# @copy-on-read: whether to enable copy on read for the device (default: false)
> +#
> +# Since: 1.6
> +##
> +{ 'type': 'BlockdevOptionsBase',
> +  'data': { 'driver': 'str',
> +            '*id': 'str',
> +            '*discard': 'BlockdevDiscardOptions',
> +            '*cache': 'BlockdevCacheOptions',
> +            '*aio':  'BlockdevAIOOptions',
> +            '*rerror': 'BlockdevOnError',
> +            '*werror': 'BlockdevOnError',
> +            '*throttling': 'BlockdevThrottlingOptions',
> +            '*read-only': 'bool',
> +            '*copy-on-read': 'bool' } }
> +
> +##
> +# @BlockdevOptionsFile
> +#
> +# Driver specific block device options for the file backend and similar
> +# protocols.
> +#
> +# @filename:    path to the image file
> +#
> +# Since: 1.6
> +##
> +{ 'type': 'BlockdevOptionsFile',
> +  'data': { 'filename': 'str' } }
> +
> +##
> +# @BlockdevOptionsFile
> +#
> +# Driver specific block device options for the NBD protocol. Either path or host
> +# must be specified.
> +#
> +# @path:        path to a unix domain socket
> +# @host:        host name for a TCP connection
> +# @port:        port number for a TCP connection (default: 10809)
> +# @export:      NBD export name
> +#
> +# Since: 1.6
> +##
> +{ 'type': 'BlockdevOptionsNBD',
> +  'data': { '*path': 'str', '*host': 'str', '*port': 'int', '*export': 'str' } }
> +
> +##
> +# @BlockdevOptionsSSH
> +#
> +# Driver specific block device options for the SSH protocol.
> +#
> +# @host:        host name for a TCP connection
> +# @port:        port number for a TCP connection (default: 22)
> +# @path:        path to the image on the remote host
> +# @user:        SSH user name
> +#
> +# @host-key-check:
> +# TODO Should this be split into multiple fields for QMP?
> +# TODO Driver takes host_key_check with underscores currently
> +#
> +# Since: 1.6
> +##
> +{ 'type': 'BlockdevOptionsSSH',
> +  'data': { 'host': 'str', '*port': 'int', 'path': 'str', '*user': 'str',
> +            '*host-key-check': 'str' } }
> +
> +##
> +# @BlockdevOptionsVVFAT
> +#
> +# Driver specific block device options for the vvfat protocol.
> +#
> +# @dir:         directory to be exported as FAT image
> +# @fat-type:    FAT type: 12, 16 or 32
> +# @floppy:      whether to export a floppy imae (true) or partitioned hard disk
> +#               (false; default)
> +# @rw:          whether to allow write operations (default: false)
> +#
> +# Since: 1.6
> +##
> +{ 'type': 'BlockdevOptionsVVFAT',
> +  'data': { 'dir': 'str', '*fat-type': 'int', '*floppy': 'bool',
> +            '*rw': 'bool' } }
> +

  Paid some time to find out the organization of options, I think well
named type can help user understand better, how about rename as:
BlockdevOptionsFile --> BlockdevOptionsProtocolFile
BlockdevOptionsNBD --> BlockdevOptionsProtocolNBD
BlockdevOptionsSSH --> BlockdevOptionsProtocolSSH
BlockdevOptionsVVFAT --> BlockdevOptionsProtocolVVFAT

BlockdevOptionsGenericFormat --> BlockdevOptionsFormatGeneric
BlockdevOptionsGenericCOWFormat -->BlockdevOptionsFormatCowGeneric
....

> +##
> +# @BlockdevOptionsGenericFormat
> +#
> +# Driver specific block device options for image format that have no option
> +# besides their data source.
> +#
> +# @file:        reference to or definition of the data source block device
> +#
> +# Since: 1.6
> +##
> +{ 'type': 'BlockdevOptionsGenericFormat',
> +  'data': { 'file': 'BlockdevRef' } }
> +
> +##
> +# @BlockdevOptionsGenericCOWFormat
> +#
> +# Driver specific block device options for image format that have no option
> +# besides their data source and an optional backing file.
> +#
> +# @file:        reference to or definition of the data source block device
> +# @backing:     reference to or definition of the backing file block device
> +#               (if missing, taken from the image file content)
> +#
> +# Since: 1.6
> +##
> +# TODO Add inheritance and base on BlockdevOptionsGenericFormat
> +{ 'type': 'BlockdevOptionsGenericCOWFormat',
> +  'data': { 'file': 'BlockdevRef', '*backing': 'BlockdevRef' } }
> +
> +##
> +# @BlockdevOptionsGenericCOWFormat
> +#
> +# Driver specific block device options for qcow2.
> +#
> +# @file:        reference to or definition of the data source block device
> +#
> +# @backing:     reference to or definition of the backing file block device
> +#               (if missing, taken from the image file content)
> +#
> +# @lazy-refcounts: whether to enable the lazy refcounts feature (default is
> +#                  taken from the image file)
> +#
> +# @pass-discard-request: whether discard requests to the qcow2 device should
> +#                        be forwarded to the data source
> +#
> +# @pass-discard-snapshot: whether discard requests for the data source should
> +#                         be issued when a snapshot operation (e.g. deleting
> +#                         a snapshot) frees clusters in the qcow2 file
> +#
> +# @pass-discard-other: whether discard requests for the data source should be
> +#                      issued on other occasions where a cluster gets freed
> +#
> +# Since: 1.6
> +##
> +# TODO Add inheritance and base on BlockdevOptionsGenericCOWFormat
> +{ 'type': 'BlockdevOptionsQcow2',
> +  'data': { 'file': 'BlockdevRef',
> +            '*backing': 'BlockdevRef',
> +            '*lazy-refcounts': 'bool',
> +            '*pass-discard-request': 'bool',
> +            '*pass-discard-snapshot': 'bool',
> +            '*pass-discard-other': 'bool' } }
> +
> +##
> +# @BlockdevOptions
> +#
> +# Options for creating a block device.
> +#
> +# Since: 1.6
> +##
> +{ 'union': 'BlockdevOptions',
> +  'base': 'BlockdevOptionsBase',
> +  'discriminator': 'driver',
> +  'data': {
> +      'file':       'BlockdevOptionsFile',
> +      'http':       'BlockdevOptionsFile',
> +      'https':      'BlockdevOptionsFile',
> +      'ftp':        'BlockdevOptionsFile',
> +      'ftps':       'BlockdevOptionsFile',
> +      'tftp':       'BlockdevOptionsFile',
> +# TODO gluster: Wait for structured options
> +# TODO iscsi: Wait for structured options
> +# TODO nbd: Should take InetSocketAddress for 'host'?
> +# TODO rbd: Wait for structured options
> +# TODO sheepdog: Wait for structured options
> +# TODO ssh: Should take InetSocketAddress for 'host'?
> +      'vvfat':      'BlockdevOptionsVVFAT',
> +
> +      'bochs':      'BlockdevOptionsGenericFormat',
> +      'cloop':      'BlockdevOptionsGenericFormat',
> +      'cow':        'BlockdevOptionsGenericCOWFormat',
> +      'dmg':        'BlockdevOptionsGenericFormat',
> +      'parallels':  'BlockdevOptionsGenericFormat',
> +      'qcow':       'BlockdevOptionsGenericCOWFormat',
> +      'qcow2':      'BlockdevOptionsQcow2',
> +      'qed':        'BlockdevOptionsGenericCOWFormat',
> +      'raw':        'BlockdevOptionsGenericFormat',
> +      'vdi':        'BlockdevOptionsGenericFormat',
> +      'vhdx':       'BlockdevOptionsGenericFormat',
> +      'vmdk':       'BlockdevOptionsGenericCOWFormat',
> +      'vpc':        'BlockdevOptionsGenericFormat'
> +  } }
> +
> +##
> +# @BlockdevRef
> +#
> +# Reference to a block device.
> +#
> +# @definition:      defines a new block device inline
> +# @reference:       references the ID of an existing block device
> +#
> +# Since: 1.6
> +##
> +{ 'union': 'BlockdevRef',
> +  'discriminator': {},
> +  'data': { 'definition': 'BlockdevOptions'
> +            'reference': 'str' } }
> +
> +##
> +# @blockdev-add:
> +#
> +# Creates a new block device.
> +#
> +# @options: block device options for the new device
> +#
> +# Since: 1.6
> +##
> +{ 'command': 'blockdev-add', 'data': { 'options': 'BlockdevOptions' } }
> diff --git a/qmp-commands.hx b/qmp-commands.hx
> index 65a9e26..96b0956 100644
> --- a/qmp-commands.hx
> +++ b/qmp-commands.hx
> @@ -3113,3 +3113,29 @@ Example:
>      }
> 
>   EQMP
> +
> +    {
> +        .name       = "blockdev-add",
> +        .args_type  = "options:q",
> +        .mhandler.cmd_new = qmp_marshal_input_blockdev_add,
> +    },
> +
> +SQMP
> +blockdev-add
> +------------
> +
> +Add a block device.
> +
> +Arguments:
> +
> +- "options": block driver options
> +
> +Example:
> +
> +-> { "execute": "blockdev-add",
> +    "arguments": { "options" : { "driver": "qcow2",
> +                                 "file": { "driver": "file",
> +                                           "filename": "test.qcow2" } } } }
> +<- { "return": {} }
> +
> +EQMP
> 


-- 
Best Regards

Wenchao Xia