From ca00bbb153d03c5338d8c8136812163f463f841e Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Wed, 6 Dec 2017 14:45:49 +0000 Subject: blockdev: add x-blockdev-set-iothread testing command 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 Reviewed-by: Kevin Wolf Reviewed-by: Eric Blake Message-id: 20171206144550.22295-9-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi --- blockdev.c | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) (limited to 'blockdev.c') diff --git a/blockdev.c b/blockdev.c index e865ae4..f75c01f 100644 --- a/blockdev.c +++ b/blockdev.c @@ -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), -- cgit v1.1