@@ -3949,3 +3949,39 @@
'data' : { 'parent': 'str',
'*child': 'str',
'*node': 'str' } }
+
+##
+# @x-blockdev-set-iothread:
+#
+# Move @node and its children into the @iothread. If @iothread is null then
+# move @node and its children into the main loop.
+#
+# The node must not be attached to a BlockBackend.
+#
+# @node-name: the name of the block driver node
+#
+# @iothread: the name of the IOThread object or null for the main loop
+#
+# Note: this command is experimental and intended for test cases that need
+# control over IOThreads only.
+#
+# Since: 2.12
+#
+# Example:
+#
+# 1. Move a node into an IOThread
+# -> { "execute": "x-blockdev-set-iothread",
+# "arguments": { "node-name": "disk1",
+# "iothread": "iothread0" } }
+# <- { "return": {} }
+#
+# 2. Move a node into the main loop
+# -> { "execute": "x-blockdev-set-iothread",
+# "arguments": { "node-name": "disk1",
+# "iothread": null } }
+# <- { "return": {} }
+#
+##
+{ 'command': 'x-blockdev-set-iothread',
+ 'data' : { 'node-name': 'str',
+ 'iothread': 'StrOrNull' } }
@@ -45,6 +45,7 @@
#include "qapi/qmp/qerror.h"
#include "qapi/qobject-output-visitor.h"
#include "sysemu/sysemu.h"
+#include "sysemu/iothread.h"
#include "block/block_int.h"
#include "qmp-commands.h"
#include "block/trace.h"
@@ -4129,6 +4130,46 @@ BlockJobInfoList *qmp_query_block_jobs(Error **errp)
return head;
}
+void qmp_x_blockdev_set_iothread(const char *node_name, StrOrNull *iothread,
+ Error **errp)
+{
+ AioContext *old_context;
+ AioContext *new_context;
+ BlockDriverState *bs;
+
+ bs = bdrv_find_node(node_name);
+ if (!bs) {
+ error_setg(errp, "Cannot find node %s", node_name);
+ return;
+ }
+
+ /* If we want to allow more extreme test scenarios this guard could be
+ * removed. For now it protects against accidents. */
+ if (bdrv_has_blk(bs)) {
+ error_setg(errp, "Node %s is in use", node_name);
+ return;
+ }
+
+ if (iothread->type == QTYPE_QSTRING) {
+ IOThread *obj = iothread_by_id(iothread->u.s);
+ if (!obj) {
+ error_setg(errp, "Cannot find iothread %s", iothread->u.s);
+ return;
+ }
+
+ new_context = iothread_get_aio_context(obj);
+ } else {
+ new_context = qemu_get_aio_context();
+ }
+
+ old_context = bdrv_get_aio_context(bs);
+ aio_context_acquire(old_context);
+
+ bdrv_set_aio_context(bs, new_context);
+
+ aio_context_release(old_context);
+}
+
QemuOptsList qemu_common_drive_opts = {
.name = "drive",
.head = QTAILQ_HEAD_INITIALIZER(qemu_common_drive_opts.head),
Currently there is no easy way for iotests to ensure that a BDS is bound to a particular IOThread. Normally the virtio-blk device calls blk_set_aio_context() when dataplane is enabled during guest driver initialization. This never happens in iotests since -machine accel=qtest means there is no guest activity (including device driver initialization). This patch adds a QMP command to explicitly assign IOThreads in test cases. See qapi/block-core.json for a description of the command. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> --- qapi/block-core.json | 36 ++++++++++++++++++++++++++++++++++++ blockdev.c | 41 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 77 insertions(+)