From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55392) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fVbMs-0008JI-8B for qemu-devel@nongnu.org; Wed, 20 Jun 2018 07:33:43 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fVbMr-0004fZ-6Z for qemu-devel@nongnu.org; Wed, 20 Jun 2018 07:33:42 -0400 References: <20180609151758.17343-1-vsementsov@virtuozzo.com> <20180609151758.17343-7-vsementsov@virtuozzo.com> From: Eric Blake Message-ID: Date: Wed, 20 Jun 2018 06:33:34 -0500 MIME-Version: 1.0 In-Reply-To: <20180609151758.17343-7-vsementsov@virtuozzo.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v5 6/6] docs/interop: add nbd.txt List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Vladimir Sementsov-Ogievskiy , qemu-block@nongnu.org, qemu-devel@nongnu.org Cc: armbru@redhat.com, pbonzini@redhat.com, mreitz@redhat.com, kwolf@redhat.com, den@openvz.org On 06/09/2018 10:17 AM, Vladimir Sementsov-Ogievskiy wrote: > Describe new metadata namespace: "qemu". > > Signed-off-by: Vladimir Sementsov-Ogievskiy > --- > docs/interop/nbd.txt | 37 +++++++++++++++++++++++++++++++++++++ > MAINTAINERS | 1 + > 2 files changed, 38 insertions(+) > create mode 100644 docs/interop/nbd.txt > > diff --git a/docs/interop/nbd.txt b/docs/interop/nbd.txt > new file mode 100644 > index 0000000000..7366269fc0 > --- /dev/null > +++ b/docs/interop/nbd.txt > @@ -0,0 +1,37 @@ > +Qemu supports NBD protocol, and has internal NBD client (look at s/supports/supports the/ > +block/nbd.c), internal NBD server (look at blockdev-nbd.c) as well as s/internal/an internal/2 > +external NBD server tool - qemu-nbd.c. The common code is placed in s/external/an external/ > +nbd/*. > + > +NBD protocol is specified here: s/NBD/The NBD/ > +https://github.com/NetworkBlockDevice/nbd/blob/master/doc/proto.md > + > +This following paragraphs describe some specific properties of NBD > +protocol realization in Qemu. > + > + > += Metadata namespaces = > + > +Qemu supports "base:allocation" metadata context as defined in the NBD s/supports/supports the/ > +protocol specification and defines own metadata namespace: "qemu". s/own/an additional/ > + > + > +== "qemu" namespace == > + > +For now, the only type of metadata context in the namespace is dirty > +bitmap. All available metadata contexts have the following form: maybe: The "qemu" namespace currently contains only one type of context, related to exposing the contents of a dirty bitmap alongside the associated disk contents. The available metadata context has the following form: > + > + qemu:dirty-bitmap: > + > +Each dirty-bitmap metadata context defines the only one flag for > +extents in reply for NBD_CMD_BLOCK_STATUS: > + > + bit 0: NBD_STATE_DIRTY, means that the extent is "dirty" > + > +For NBD_OPT_LIST_META_CONTEXT the following queries are supported > +additionally to "qemu:dirty-bitmap:": s/additionally/in addition/ > + > +* "qemu:" : returns list of all available metadata contexts in the > + namespace. > +* "qemu:dirty-bitmap:" : returns list of all available dirty-bitmap > + metadata contexts. > diff --git a/MAINTAINERS b/MAINTAINERS > index e187b1f18f..887b479440 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -1923,6 +1923,7 @@ F: nbd/ > F: include/block/nbd* > F: qemu-nbd.* > F: blockdev-nbd.c > +F: docs/interop/nbd.txt > T: git git://repo.or.cz/qemu/ericb.git nbd > > NFS > Reviewed-by: Eric Blake At this point, I think I'll touch up the issues I've spotted and submit a pull request, in order to make it easier for me to test my libvirt code. -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org