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| author | Fam Zheng <famz@redhat.com> | 2014-09-11 14:09:56 +0800 |
|---|---|---|
| committer | Stefan Hajnoczi <stefanha@redhat.com> | 2014-09-22 11:39:23 +0100 |
| commit | e819ab22777fd455d5b130afe48c808d35ef7e93 (patch) | |
| tree | 7701c3c369c7c9e03e17e84aca651c679b8d67ac /qapi | |
| parent | a90d411e63ef29bb99b984e0fdb7796aeee1c724 (diff) | |
| download | qemu-e819ab22777fd455d5b130afe48c808d35ef7e93.tar.gz | |
block: Introduce "null" drivers
This is an analogue to Linux null_blk. It can be used for testing or
benchmarking block device emulation and general block layer
functionalities such as coroutines and throttling, where disk IO is not
necessary or wanted.
Use null-aio:// for AIO version, and null-co:// for coroutine version.
[Resolved conflict with Fam's async bdrv_aio_cancel() series:
1. Drop .bdrv_aio_cancel() since it is now done by block.c
2. Rename qemu_aio_release() to qemu_aio_unref()
--Stefan]
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Benoît Canet <benoit.canet@nodalink.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1410415798-20673-2-git-send-email-famz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'qapi')
| -rw-r--r-- | qapi/block-core.json | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/qapi/block-core.json b/qapi/block-core.json index 95dcd81ed4..a886b5d3e4 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -1151,7 +1151,8 @@ 'data': [ 'archipelago', 'file', 'host_device', 'host_cdrom', 'host_floppy', 'http', 'https', 'ftp', 'ftps', 'tftp', 'vvfat', 'blkdebug', 'blkverify', 'bochs', 'cloop', 'cow', 'dmg', 'parallels', 'qcow', - 'qcow2', 'qed', 'raw', 'vdi', 'vhdx', 'vmdk', 'vpc', 'quorum' ] } + 'qcow2', 'qed', 'raw', 'vdi', 'vhdx', 'vmdk', 'vpc', 'quorum', + 'null-aio', 'null-co' ] } ## # @BlockdevOptionsBase @@ -1204,6 +1205,18 @@ 'data': { 'filename': 'str' } } ## +# @BlockdevOptionsNull +# +# Driver specific block device options for the null backend. +# +# @size: #optional size of the device in bytes. +# +# Since: 2.2 +## +{ 'type': 'BlockdevOptionsNull', + 'data': { '*size': 'int' } } + +## # @BlockdevOptionsVVFAT # # Driver specific block device options for the vvfat protocol. @@ -1503,7 +1516,9 @@ 'vhdx': 'BlockdevOptionsGenericFormat', 'vmdk': 'BlockdevOptionsGenericCOWFormat', 'vpc': 'BlockdevOptionsGenericFormat', - 'quorum': 'BlockdevOptionsQuorum' + 'quorum': 'BlockdevOptionsQuorum', + 'null-aio': 'BlockdevOptionsNull', + 'null-co': 'BlockdevOptionsNull' } } ## |