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

[Kevin Wolf <kwolf@redhat.com>]

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' } }
+
+##
+# @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
-- 
1.8.1.4