From: Eric Blake <eblake@redhat.com>
To: Markus Armbruster <armbru@redhat.com>,
Wen Congyang <wency@cn.fujitsu.com>
Cc: Kevin Wolf <kwolf@redhat.com>, Alberto Garcia <berto@igalia.com>,
zhanghailiang <zhang.zhanghailiang@huawei.com>,
qemu block <qemu-block@nongnu.org>,
Jiang Yunhong <yunhong.jiang@intel.com>,
Dong Eddie <eddie.dong@intel.com>,
qemu devel <qemu-devel@nongnu.org>,
"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
Gonglei <arei.gonglei@huawei.com>,
Stefan Hajnoczi <stefanha@redhat.com>,
Yang Hongyang <yanghy@cn.fujitsu.com>
Subject: Re: [Qemu-devel] [PATCH v3 1/5] support nbd driver in blockdev-add
Date: Tue, 15 Sep 2015 07:03:39 -0600 [thread overview]
Message-ID: <55F8172B.5020209@redhat.com> (raw)
In-Reply-To: <87fv2g876a.fsf@blackfin.pond.sub.org>
[-- Attachment #1: Type: text/plain, Size: 2297 bytes --]
On 09/15/2015 01:37 AM, Markus Armbruster wrote:
>>>>> +# @filename: #optional unix or inet path. The format is:
>>>>> +# unix: nbd+unix:///export?socket=path or
>>>>> +# nbd:unix:path:exportname=export
>>>>> +# inet: nbd[+tcp]://host[:port]/export or
>>>>> +# nbd:host[:port]:exportname=export
>>>
> Since there's an either/or, the complex QAPI type should be a union.
>
>>> { 'enum': 'NBDTransport', 'data': ['unix', 'tcp', 'udp'] }
>>
>> NBD only uses tcp, it doesn't support udp.
Fair enough.
>>
>>> { 'union': 'BlockdevOptionsNBD',
>>> 'base': { 'transport': 'NBDTransport', 'export': 'str' },
>>> 'discriminator': 'transport',
>>> 'data': { 'unix': 'NBDUnix', 'tcp': 'NBDInet', 'udp': 'NBDInet' } }
>>> { 'struct': 'NBDUnix', 'data': { 'socket': 'str' } }
>>
>> unix socket needs a path, and I think we can use UnixSocketAddress here.
Sure, if that works, you could do 'unix':'UnixSocketAddress' instead of
inventing 'NBDUnix'.
>
> Yes, we should try to reuse common types like SocketAddress,
> InetSocketAddress, UnixSocketAddress.
Well, we've already questioned whether 'InetSocketAddress' needs to be
fixed to be separate from a socket range, but it can be a separate fix.
>
> Perhaps it could be as simple as
>
> { 'struct': 'BlockdevOptionsNBD',
> 'data': { 'addr: 'SocketAddress', 'export': 'str' } }
>
> Eric, what do you think?
It has more nesting on the wire, but should work. That is, to express
"nbd+unix:///export?socket=path", the QMP would be:
{ "export":"export", "addr":{ "type":"unix", "data":{ "path": "str"}}}
instead of a nicer:
{ "export":"export", "type":"unix", "path":"str" }
but the advantage of working now rather than waiting on qapi fixes in
the pipeline has its benefit.
There's also the question of how to handle 'fd', if NBD can't reuse an
existing fd but must be given a unix socket filename or tcp host/port
destination. Documenting that we reject a combination may be okay,
except that it is harder to introspect later if the combination is no
longer rejected because we later add support.
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 604 bytes --]
next prev parent reply other threads:[~2015-09-15 13:22 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-10 9:55 [Qemu-devel] [PATCH v3 0/5] qapi: child add/delete support Wen Congyang
2015-09-10 9:55 ` [Qemu-devel] [PATCH v3 1/5] support nbd driver in blockdev-add Wen Congyang
2015-09-14 14:27 ` Markus Armbruster
2015-09-14 15:47 ` Eric Blake
2015-09-15 1:39 ` Wen Congyang
2015-09-15 7:37 ` Markus Armbruster
2015-09-15 8:01 ` Wen Congyang
2015-09-15 11:12 ` Markus Armbruster
2015-09-16 5:59 ` Wen Congyang
2015-09-16 8:21 ` Markus Armbruster
2015-09-16 8:24 ` Wen Congyang
2015-09-16 11:18 ` Markus Armbruster
2015-09-16 14:53 ` [Qemu-devel] [Qemu-block] " Eric Blake
2015-09-17 1:06 ` Wen Congyang
2015-09-17 1:04 ` [Qemu-devel] " Wen Congyang
2015-09-17 5:01 ` Markus Armbruster
2015-09-15 13:03 ` Eric Blake [this message]
2015-09-15 13:26 ` Kevin Wolf
2015-09-15 2:20 ` Wen Congyang
2015-09-15 2:27 ` Wen Congyang
2015-09-15 3:46 ` Eric Blake
2015-09-15 3:58 ` Wen Congyang
2015-09-15 13:11 ` Eric Blake
2015-09-16 7:11 ` Wen Congyang
2015-09-16 14:55 ` Eric Blake
2015-09-10 9:55 ` [Qemu-devel] [PATCH v3 2/5] Add new block driver interface to add/delete a BDS's child Wen Congyang
2015-09-10 9:55 ` [Qemu-devel] [PATCH v3 3/5] quorum: implement bdrv_add_child() and bdrv_del_child() Wen Congyang
2015-09-10 9:55 ` [Qemu-devel] [PATCH v3 4/5] qmp: add monitor command to add/remove a child Wen Congyang
2015-09-10 10:04 ` Daniel P. Berrange
2015-09-10 10:34 ` Wen Congyang
2015-09-14 14:36 ` Markus Armbruster
2015-09-14 15:34 ` Kevin Wolf
2015-09-14 16:09 ` Markus Armbruster
2015-09-15 2:40 ` Wen Congyang
2015-09-15 7:49 ` Markus Armbruster
2015-09-15 7:57 ` Wen Congyang
2015-09-16 6:31 ` Wen Congyang
2015-09-16 8:29 ` Markus Armbruster
2015-09-14 15:37 ` Kevin Wolf
2015-09-15 2:33 ` Wen Congyang
2015-09-15 8:56 ` Alberto Garcia
2015-09-15 9:20 ` Kevin Wolf
2015-09-15 9:26 ` [Qemu-devel] [Qemu-block] " Kevin Wolf
2015-09-10 9:55 ` [Qemu-devel] [PATCH v3 5/5] hmp: " Wen Congyang
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=55F8172B.5020209@redhat.com \
--to=eblake@redhat.com \
--cc=arei.gonglei@huawei.com \
--cc=armbru@redhat.com \
--cc=berto@igalia.com \
--cc=dgilbert@redhat.com \
--cc=eddie.dong@intel.com \
--cc=kwolf@redhat.com \
--cc=qemu-block@nongnu.org \
--cc=qemu-devel@nongnu.org \
--cc=stefanha@redhat.com \
--cc=wency@cn.fujitsu.com \
--cc=yanghy@cn.fujitsu.com \
--cc=yunhong.jiang@intel.com \
--cc=zhang.zhanghailiang@huawei.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.