Add a command that can replace bs in following BdrvChild structures: - qdev blk root child - block-export blk root child - any child of BlockDriverState selected by child-name
Signed-off-by: Vladimir Sementsov-Ogievskiy <[email protected]> --- blockdev.c | 56 +++++++++++++++++++++++++++ qapi/block-core.json | 88 ++++++++++++++++++++++++++++++++++++++++++ stubs/blk-by-qdev-id.c | 13 +++++++ stubs/meson.build | 1 + 4 files changed, 158 insertions(+) create mode 100644 stubs/blk-by-qdev-id.c diff --git a/blockdev.c b/blockdev.c index ba7e90b06e..2190467022 100644 --- a/blockdev.c +++ b/blockdev.c @@ -3559,6 +3559,62 @@ void qmp_x_blockdev_set_iothread(const char *node_name, StrOrNull *iothread, bdrv_try_change_aio_context(bs, new_context, NULL, errp); } +void qmp_blockdev_replace(BlockdevReplace *repl, Error **errp) +{ + BdrvChild *child = NULL; + BlockDriverState *new_child_bs; + + if (repl->parent_type == BLOCK_PARENT_TYPE_DRIVER) { + BlockDriverState *parent_bs; + + parent_bs = bdrv_find_node(repl->u.driver.node_name); + if (!parent_bs) { + error_setg(errp, "Block driver node with node-name '%s' not " + "found", repl->u.driver.node_name); + return; + } + + child = bdrv_find_child(parent_bs, repl->u.driver.child); + if (!child) { + error_setg(errp, "Block driver node '%s' doesn't have child " + "named '%s'", repl->u.driver.node_name, + repl->u.driver.child); + return; + } + } else { + /* Other types are similar, they work through blk */ + BlockBackend *blk; + bool is_qdev = repl->parent_type == BLOCK_PARENT_TYPE_QDEV; + const char *id = + is_qdev ? repl->u.qdev.qdev_id : repl->u.export.export_id; + + assert(is_qdev || repl->parent_type == BLOCK_PARENT_TYPE_EXPORT); + + blk = is_qdev ? blk_by_qdev_id(id, errp) : blk_by_export_id(id, errp); + if (!blk) { + return; + } + + child = blk_root(blk); + if (!child) { + error_setg(errp, "%s '%s' is empty, nothing to replace", + is_qdev ? "Device" : "Export", id); + return; + } + } + + assert(child); + assert(child->bs); + + new_child_bs = bdrv_find_node(repl->new_child); + if (!new_child_bs) { + error_setg(errp, "Node '%s' not found", repl->new_child); + return; + } + + bdrv_replace_child_bs(child, new_child_bs, errp); +} + QemuOptsList qemu_common_drive_opts = { .name = "drive", .head = QTAILQ_HEAD_INITIALIZER(qemu_common_drive_opts.head), diff --git a/qapi/block-core.json b/qapi/block-core.json index df5e07debd..0a6f08a6e0 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -6148,3 +6148,91 @@ ## { 'struct': 'DummyBlockCoreForceArrays', 'data': { 'unused-block-graph-info': ['BlockGraphInfo'] } } + +## +# @BlockParentType: +# +# @qdev: block device, such as created by device_add, and denoted by +# qdev-id +# +# @driver: block driver node, such as created by blockdev-add, and +# denoted by node-name +# +# @export: block export, such created by block-export-add, and +# denoted by export-id +# +# Since 9.1 +## +{ 'enum': 'BlockParentType', + 'data': ['qdev', 'driver', 'export'] } + +## +# @BdrvChildRefQdev: +# +# @qdev-id: the device's ID or QOM path +# +# Since 9.1 +## +{ 'struct': 'BdrvChildRefQdev', + 'data': { 'qdev-id': 'str' } } + +## +# @BdrvChildRefExport: +# +# @export-id: block export identifier +# +# Since 9.1 +## +{ 'struct': 'BdrvChildRefExport', + 'data': { 'export-id': 'str' } } + +## +# @BdrvChildRefDriver: +# +# @node-name: the node name of the parent block node +# +# @child: name of the child to be replaced, like "file" or "backing" +# +# Since 9.1 +## +{ 'struct': 'BdrvChildRefDriver', + 'data': { 'node-name': 'str', 'child': 'str' } } + +## +# @BlockdevReplace: +# +# @parent-type: type of the parent, which child is to be replaced +# +# @new-child: new child for replacement +# +# Since 9.1 +## +{ 'union': 'BlockdevReplace', + 'base': { + 'parent-type': 'BlockParentType', + 'new-child': 'str' + }, + 'discriminator': 'parent-type', + 'data': { + 'qdev': 'BdrvChildRefQdev', + 'export': 'BdrvChildRefExport', + 'driver': 'BdrvChildRefDriver' + } } + +## +# @blockdev-replace: +# +# Replace a block-node associated with device (selected by +# @qdev-id) or with block-export (selected by @export-id) or +# any child of block-node (selected by @node-name and @child) +# with @new-child block-node. +# +# Features: +# +# @unstable: This command is experimental. +# +# Since 9.1 +## +{ 'command': 'blockdev-replace', 'boxed': true, + 'features': [ 'unstable' ], + 'data': 'BlockdevReplace' } diff --git a/stubs/blk-by-qdev-id.c b/stubs/blk-by-qdev-id.c new file mode 100644 index 0000000000..5ec9f755ee --- /dev/null +++ b/stubs/blk-by-qdev-id.c @@ -0,0 +1,13 @@ +#include "qemu/osdep.h" +#include "qapi/error.h" +#include "sysemu/block-backend.h" + +BlockBackend *blk_by_qdev_id(const char *id, Error **errp) +{ + /* + * We expect this when blockdev-change is called with parent-type=qdev, + * but qdev-monitor is not linked in. So no blk_ API is not available. + */ + error_setg(errp, "Parameter 'parent-type' does not accept value 'qdev'"); + return NULL; +} diff --git a/stubs/meson.build b/stubs/meson.build index 772a3e817d..068998c1a5 100644 --- a/stubs/meson.build +++ b/stubs/meson.build @@ -15,6 +15,7 @@ if have_block stub_ss.add(files('bdrv-next-monitor-owned.c')) stub_ss.add(files('blk-commit-all.c')) stub_ss.add(files('blk-exp-close-all.c')) + stub_ss.add(files('blk-by-qdev-id.c')) stub_ss.add(files('blockdev-close-all-bdrv-states.c')) stub_ss.add(files('change-state-handler.c')) stub_ss.add(files('get-vm-name.c')) -- 2.34.1
