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([2a01:e0a:466:71c0:7440:4d06:49b0:1f79]) by smtp.gmail.com with ESMTPSA id 2sm23268821wrq.31.2020.01.15.01.34.09 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 15 Jan 2020 01:34:10 -0800 (PST) Mime-Version: 1.0 (Mac OS X Mail 13.0 \(3608.40.2.2.4\)) Subject: Re: Making QEMU easier for management tools and applications From: Christophe de Dinechin In-Reply-To: <87o8v52hz9.fsf@dusky.pond.sub.org> Date: Wed, 15 Jan 2020 10:34:09 +0100 Message-Id: <8CF8359B-1E52-4F7A-944E-C1C14FEC4F92@redhat.com> References: <1EFEF446-AFEA-429F-B6BA-3206A7C41836@redhat.com> <20200108104306.GC5057@dhcp-200-226.str.redhat.com> <97F153BD-FB8A-46C7-90D0-9E894B9E0292@redhat.com> <20200108133842.GE5057@dhcp-200-226.str.redhat.com> <87d0bmchq0.fsf@dusky.pond.sub.org> <1B253197-5592-472A-AA26-E0614A13C91A@redhat.com> <87o8v52hz9.fsf@dusky.pond.sub.org> To: Markus Armbruster X-Mailer: Apple Mail (2.3608.40.2.2.4) X-MC-Unique: 200IvHKWMAmhCbYNmQKmDg-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.120 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 , Peter Maydell , "Daniel P. Berrange" , "Denis V. Lunev" , Stefan Hajnoczi , qemu-devel , Paolo Bonzini , =?utf-8?Q?Marc-Andr=C3=A9_Lureau?= , John Snow , Dominik Csapak Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Thanks a bunch. This clarifies a number of my misconceptions about how this is currently used. Most notably this one: > On 15 Jan 2020, at 10:20, Markus Armbruster wrote: >=20 >> We don=E2=80=99t want the QAPI to let arbitrary fields of a QOM object >> be modified, do we? >=20 > We already do: QMP command qom-set. If it breaks your guest, you get to > keep the pieces. Ouch. I certainly did not expect that. "It is not what you don=E2=80=99t know that kills you, it is what you know = that ain=E2=80=99t so". >=20 >>> http://dreamsongs.com/RiseOfWorseIsBetter.html >>=20 >> You know that I positively hate this ;-) >=20 > It's been a tough lesson for me, too. Not sure I can call it a =E2=80=9Clesson=E2=80=9D. Much like a philosophy t= o fight against, IMO. >> Well, I guess we can expand the schema. #ILoveJSON. >=20 > Basing the QAPI language on JSON was a poor choice. Not sure that's > fixable at a reasonable cost. Well, at least now I have a slightly better understanding of the related co= sts and trade-offs. Thanks a lot for explaining. Christophe