From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:33734) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gkWhj-0005oQ-6D for qemu-devel@nongnu.org; Fri, 18 Jan 2019 11:09:12 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gkWhZ-0007Hg-4m for qemu-devel@nongnu.org; Fri, 18 Jan 2019 11:09:03 -0500 References: <20190117193658.16413-1-eblake@redhat.com> From: Eric Blake Message-ID: <39599bab-cf0f-80d1-a9f4-d7735da2fe28@redhat.com> Date: Fri, 18 Jan 2019 10:08:26 -0600 MIME-Version: 1.0 In-Reply-To: <20190117193658.16413-1-eblake@redhat.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="kAT7CinLnBqX9yGLPTCnDN9vtEqDtjKs8" Subject: Re: [Qemu-devel] [PATCH v4 00/21] nbd: add qemu-nbd --list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: nsoffer@redhat.com, vsementsov@virtuozzo.com, jsnow@redhat.com, rjones@redhat.com, qemu-block@nongnu.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --kAT7CinLnBqX9yGLPTCnDN9vtEqDtjKs8 From: Eric Blake To: qemu-devel@nongnu.org Cc: nsoffer@redhat.com, vsementsov@virtuozzo.com, jsnow@redhat.com, rjones@redhat.com, qemu-block@nongnu.org Message-ID: <39599bab-cf0f-80d1-a9f4-d7735da2fe28@redhat.com> Subject: Re: [Qemu-devel] [PATCH v4 00/21] nbd: add qemu-nbd --list References: <20190117193658.16413-1-eblake@redhat.com> In-Reply-To: <20190117193658.16413-1-eblake@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 1/17/19 1:36 PM, Eric Blake wrote: > I got tired of debugging whether a server was advertising the > correct things during negotiation by inspecting the trace > logs of qemu-io as client - not to mention that without SOME > sort of client tracing particular commands, we can't easily > regression test the server for correct behavior. The final > straw was at KVM Forum, when Nir asked me to make sure there > was a way to easily determine if an NBD server is exposing what > we really want (and fixing x-dirty-bitmap to behave saner fell > out as a result of answering that question). >=20 > I note that upstream NBD has 'nbd-client -l $host' for querying > just export names (with no quoting, so you have to know that > a blank line means the default export), but it wasn't powerful > enough, so I implemented 'qemu-nbd -L' to document everything. > Upstream NBD has separate 'nbd-client' and 'nbd-server' binaries, > while we only have 'qemu-nbd' (which is normally just a server, > but 'qemu-nbd -c' also operates a second thread as a client). > Our other uses of qemu as NBD client are for consuming a block > device (as in qemu-io, qemu-img, or a drive to qemu) - but those > binaries are less suited to something so specific to the NBD > protocol. >=20 > Bonus: As a result of my work on this series, nbdkit now supports > NBD_OPT_INFO (my interoperability testing between server > implementations has been paying off, both at fixing server bugs, > and at making this code more reliable across difference in valid > servers). >=20 > Also available at: > https://repo.or.cz/qemu/ericb.git qemu-nbd-list-v4 Vladimir spotted a few more tweaks to make, but they all look sufficiently minor that I'll go ahead and queue this on my NBD tree for a pull request on Monday, rather than posting a v5, if there aren't any other major comments in the meantime. --=20 Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org --kAT7CinLnBqX9yGLPTCnDN9vtEqDtjKs8 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEccLMIrHEYCkn0vOqp6FrSiUnQ2oFAlxB+foACgkQp6FrSiUn Q2rNnwf/Q2FTN1gBYq97WnN/MGCqElADDyGCZqP2oAjy8GOobm5ZIZjqioOCfyjz y0R48BkzXidJ0u9OQKXIsq321YmUYbGpWs2Kh2/0ZXrHKNSWm87TjHQ2wDTlhOKf FL2ekVXbtMY7WLjsRp9TxTWwcXB04ZNNeZ+jdavcDoDapLe/iPbt3IN0C+V3wJ05 hYMJtvghLnKbeM9z8kIBClfd1Xch6EAjBj1DC2dLXoycoCJdAcZuN8YfrDpzCgkg xmiAhvhDXA5ncAUQH86lNNVhK9afc/ipsSXptntdFPIXBGZNLz5zdLn5ELuhwG3h ngwZeCOtVGxi4unH4n2d9KGBWJcjZQ== =8qP/ -----END PGP SIGNATURE----- --kAT7CinLnBqX9yGLPTCnDN9vtEqDtjKs8--