Make it possible to specify the iothread where the export will run.
Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com>
---
Note the x-blockdev-set-iothread QMP command can be used to do the same,
but not from the command-line. And it requires sending an additional
command.
In the long run vhost-user-blk will support per-virtqueue iothread
mappings. But for now a single iothread makes sense and most other
transports will just use one iothread anyway.
---
qapi/block-export.json | 4 ++++
block/export/export.c | 26 +++++++++++++++++++++++++-
2 files changed, 29 insertions(+), 1 deletion(-)
diff --git a/qapi/block-export.json b/qapi/block-export.json
index 87ac5117cd..eba6f6eae9 100644
--- a/qapi/block-export.json
+++ b/qapi/block-export.json
@@ -219,11 +219,15 @@
# export before completion is signalled. (since: 5.2;
# default: false)
#
+# @iothread: The name of the iothread object where the export will run. The
+# default is the main loop thread. (since: 5.2)
+#
# Since: 4.2
##
{ 'union': 'BlockExportOptions',
'base': { 'type': 'BlockExportType',
'id': 'str',
+ '*iothread': 'str',
'node-name': 'str',
'*writable': 'bool',
'*writethrough': 'bool' },
diff --git a/block/export/export.c b/block/export/export.c
index 550897e236..0fb3d76ee3 100644
--- a/block/export/export.c
+++ b/block/export/export.c
@@ -15,6 +15,7 @@
#include "block/block.h"
#include "sysemu/block-backend.h"
+#include "sysemu/iothread.h"
#include "block/export.h"
#include "block/nbd.h"
#include "qapi/error.h"
@@ -66,7 +67,7 @@ BlockExport *blk_exp_add(BlockExportOptions *export, Error
**errp)
const BlockExportDriver *drv;
BlockExport *exp = NULL;
BlockDriverState *bs;
- BlockBackend *blk;
+ BlockBackend *blk = NULL;
AioContext *ctx;
uint64_t perm;
int ret;
@@ -102,6 +103,29 @@ BlockExport *blk_exp_add(BlockExportOptions *export, Error
**errp)
ctx = bdrv_get_aio_context(bs);
aio_context_acquire(ctx);
+ if (export->has_iothread) {
+ IOThread *iothread;
+ AioContext *new_ctx;
+
+ iothread = iothread_by_id(export->iothread);
+ if (!iothread) {
+ error_setg(errp, "iothread \"%s\" not found", export->iothread);
+ goto fail;
+ }
+
+ new_ctx = iothread_get_aio_context(iothread);
+
+ ret = bdrv_try_set_aio_context(bs, new_ctx, errp);
+ if (ret != 0) {
+ goto fail;
+ }
+
+ aio_context_release(ctx);
+ aio_context_acquire(new_ctx);
+
+ ctx = new_ctx;
+ }
+
/*
* Block exports are used for non-shared storage migration. Make sure
* that BDRV_O_INACTIVE is cleared and the image is ready for write
--
2.26.2
