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b=g0XFcf3cjkpZfcrqUwQitvrKmlP98tPcyTnjSnvzMg66SOi6t7XrWE37A1U2u+mWL nZ+Znb/oYe3BtFUXtdoiJ58lzNOjNwajGcDZqoKPrfwnOgZON8PUYlJH5wCnaV+I0v s54xKEEAcl9jADLPZ93IGIu6ci8YiaDxcoKyzbLw= X-UI-Sender-Class: c548c8c5-30a9-4db5-a2e7-cb6cb037b8f9 Received: from luklap ([89.247.255.130]) by smtp.web.de (mrweb006 [213.165.67.108]) with ESMTPSA (Nemesis) id 1MumJD-1jGW5A162t-00ro9q; Tue, 12 May 2020 21:42:43 +0200 Date: Tue, 12 May 2020 21:42:18 +0200 From: Lukas Straub To: "Daniel P. =?UTF-8?B?QmVycmFuZ8Op?=" Subject: Re: [PATCH 0/5] Introduce 'yank' oob qmp command to recover from hanging qemu Message-ID: <20200512214218.007953fa@luklap> In-Reply-To: <20200512094337.GK1191162@redhat.com> References: <20200511114947.GJ1135885@redhat.com> <20200511120718.GD2811@work-vm> <20200511121714.GL1135885@redhat.com> <20200511154645.GI2811@work-vm> <20200512113206.62836e44@luklap> <20200512094337.GK1191162@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="Sig_/xqBLJNooJjZa=lfK8+ANU4="; protocol="application/pgp-signature"; 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envelope-from=lukasstraub2@web.de; helo=mout.web.de X-detected-operating-system: by eggs.gnu.org: First seen = 2020/05/12 15:42:47 X-ACL-Warn: Detected OS = Linux 3.11 and newer X-Spam_score_int: -24 X-Spam_score: -2.5 X-Spam_bar: -- X-Spam_report: (-2.5 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_ENVFROM_END_DIGIT=0.25, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_PASS=-0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , qemu-block , Juan Quintela , qemu-devel , Max Reitz , =?UTF-8?B?TWFy?= =?UTF-8?B?Yy1BbmRyw6k=?= Lureau , Paolo Bonzini , "Dr. David Alan Gilbert" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" --Sig_/xqBLJNooJjZa=lfK8+ANU4= Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Tue, 12 May 2020 10:43:37 +0100 Daniel P. Berrang=C3=A9 wrote: > On Tue, May 12, 2020 at 11:32:06AM +0200, Lukas Straub wrote: > > ...=20 > >=20 > > Good Idea. We could name the connections (/yank callbacks) in the > > form "nbd:", "chardev:" and "migration" > > (and add "netdev:...", etc. in the future). Then make yank take a > > list of connection names as you suggest and silently ignore connections > > that don't exist. And maybe even add a 'query-yank' oob command returni= ng > > a list of registered connections so the management application can do > > pattern matching if it wants. =20 >=20 > Yes, that would make the yank command much more flexible in how it can > be used. >=20 > As an alternative to using formatted strings like this, it could be > modelled more explicitly in QAPI >=20 > { 'struct': 'YankChannels', > 'data': { 'chardev': [ 'string' ], > 'nbd': ['string'], > 'migration': bool } } >=20 > In this example, 'chardev' would accept a list of chardev IDs which > have it enabled, 'nbd' would accept a list of block node IDs which > have it enabled, and migration is a singleton on/off. With the new command, the yank feature can then be enabled unconditionally = on the instances. > The benefit of this modelling is that you can introspect QEMU > to discover what classes of channels support being yanked by > this QEMU build, as well as what instances are configured to > be yanked. ie you can distinguish between a QEMU that doesn't > support yanking network devices, from a QEMU that does support > yanking network devices, but doesn't have it enabled for any > network device instances. >=20 > Regards, > Daniel --Sig_/xqBLJNooJjZa=lfK8+ANU4= Content-Type: application/pgp-signature Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEEg/qxWKDZuPtyYo+kNasLKJxdslgFAl66/BoACgkQNasLKJxd slg51Q/+OtkIVnO+Ek/GqwuRguCtBxFA+VScox5f4JENNirL+bXxXjzX0+USuasb flB+r9fGLUjQUuY2fNkXy7yg4a8lh4wjN82pQC7kalqynMBS759KTiDe3hRxJl7j fZhUMINqMgzV5Qrn/ZIiZU5lL2RzpWTbO88WDhQsSEZJBvSpPrantGVyB/UAeoXs xzzi1AHoasGu7CNQXel9lYarB9R99NwYdrkzNgk1t+0UxYzXYRu2gUAWNgHm5hv5 h5MCr2CFYEe2pXsWhtRBoS7/Ri8VcziD/tbI1glVDFKxAe+RGhmJzJuZArgnUvMv et5gAhFbdbAyKSvTNWBNUWQZtA3t4c2lwO0LE0NipxZmfIX+UupnzzaVBzrtPNB+ XgDI8UQaQs1two0BItAmbpBhFM7YOOUrS3cM/elRCcyjhDXug55Q2oCYbas9tgcH qtS1tIp3MA/P/g+9d6cGIZV3snKw6BMGlSCa/QCs1Xk1hbsJ3z9dF+4MZfmLqJhl ms0PoFYHjMuu281htSON7MKFjlJ2DWLCo9ptsGTX8osDhM4PRQdQftiS7+bH3/OI q0/xvVlNvbbXe1kmp8+eCHOPlYMSLdl8tw2dJwqdKLrASEBZVmQiINQErObL1Gzl iqZxG2Ic1C36n/EkxCc4FCnUoebCuOGcS9oJY8CEShB4caL1Aps= =RyaK -----END PGP SIGNATURE----- --Sig_/xqBLJNooJjZa=lfK8+ANU4=--