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To: Markus Armbruster References: <87tv0vzrwj.fsf@dusky.pond.sub.org> <6fc8633a-6d91-b83a-e6cd-5f714ccaf9ea@redhat.com> <875zda8j3m.fsf@dusky.pond.sub.org> From: Paolo Bonzini Message-ID: Date: Tue, 5 May 2020 18:26:57 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: <875zda8j3m.fsf@dusky.pond.sub.org> Content-Language: en-US X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=207.211.31.81; envelope-from=pbonzini@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/05/05 00:37:19 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-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: "Daniel P. Berrange" , qemu-devel@nongnu.org, Eduardo Habkost Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 05/05/20 18:03, Markus Armbruster wrote: >> That's a good one, and especially a safe one, since it matches >> qdev_device_add. It has the disadvantage of having to touch all >> qdev_create() calls. > > Also, it moves onboard devices from /machine/unattached/ to > /machine/peripheral-anon/. Uh indeed. No that's too ugly. >> Even better however would be to move the bus argument (and thus >> qdev_set_parent_bus) to qdev_init, and likewise in qdev_device_add move >> qdev_set_id after qemu_opt_foreach. I looked at the property setters >> and couldn't find anything suspicious (somewhat to my surprise), but I >> haven't honestly tried. > > Thus, we satisfy bus_unparent()'s precondition "bus children have a QOM > parent"[*] by moving "add to parent bus" next to the place where we > ensure "has QOM parent" by putting orphans under /machine/unattached/. > Makes sense. > > If we add to the bus first, the precondition ceases to hold until we > realize. Ugly, but harmless unless we manage to actually call the > function then. Shouldn't be a big deal, since users should call either qdev_set_id or object_property_add_child before device_set_realized. > I suspect we can't realize first, because the realize method may want to > use the parent bus. Right. Moving the bus to qdev_init would be quite large but hopefully scriptable. Paolo