From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36815) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1f3NuV-0004yr-JP for qemu-devel@nongnu.org; Tue, 03 Apr 2018 11:31:49 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1f3NuS-0003hf-Br for qemu-devel@nongnu.org; Tue, 03 Apr 2018 11:31:47 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56698) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1f3NuS-0003hJ-2n for qemu-devel@nongnu.org; Tue, 03 Apr 2018 11:31:44 -0400 Date: Tue, 3 Apr 2018 12:31:29 -0300 From: Eduardo Habkost Message-ID: <20180403153129.GV5046@localhost.localdomain> References: <1520860275-101576-1-git-send-email-imammedo@redhat.com> <1520860275-101576-4-git-send-email-imammedo@redhat.com> <20180323212508.GF28161@localhost.localdomain> <20180327170541.295fc29a@redhat.com> <20180328134835.04f95535@redhat.com> <20180328192148.GR5046@localhost.localdomain> <20180329134303.548a864b@redhat.com> <20180329162409.GX5046@localhost.localdomain> <20180403163253.1d13633f@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180403163253.1d13633f@redhat.com> Subject: Re: [Qemu-devel] [PATCH v4 3/9] cli: add -preconfig option List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Igor Mammedov Cc: peter.maydell@linaro.org, pkrempa@redhat.com, cohuck@redhat.com, qemu-devel@nongnu.org, armbru@redhat.com, pbonzini@redhat.com, david@gibson.dropbear.id.au On Tue, Apr 03, 2018 at 04:32:53PM +0200, Igor Mammedov wrote: > On Thu, 29 Mar 2018 13:24:09 -0300 > Eduardo Habkost wrote: > > > On Thu, Mar 29, 2018 at 01:43:03PM +0200, Igor Mammedov wrote: > > > On Wed, 28 Mar 2018 16:21:48 -0300 > > > Eduardo Habkost wrote: > > > > > > > On Wed, Mar 28, 2018 at 01:48:35PM +0200, Igor Mammedov wrote: > > > > > On Tue, 27 Mar 2018 17:05:41 +0200 > > > > > Igor Mammedov wrote: > > > > > > > > > > > On Fri, 23 Mar 2018 18:25:08 -0300 > > > > > > Eduardo Habkost wrote: > [...] > > > > This doesn't make sense to me. Why would we enter > > > > RUN_STATE_PRECONFIG state if -preconfig is not used at all? > > > because of RUN_STATE_PRECONFIG becomes new initial state of > > > our state machine where we start of (used to be RUN_STATE_PRELAUNCH) > > > > Oh, I missed that part. > > > > > Lets call it variant 1: > > > > > > with this we have 2 possible transitions: > > > RUN_STATE_PRECONFIG -> RUN_STATE_PRELAUNCH (machine_init) > > > > > > and > > > > > > RUN_STATE_PRECONFIG -> RUN_STATE_INMIGRATE > > > ugly but it was the same with RUN_STATE_PRELAUNCH initial transition > [...] > > > > Thanks, now variant 1 makes more sense to me. But I really miss > > here are very clear and explicit descriptions of what each state > > really mean, and what are the differences between them. > > > > It looks like the existing description for `prelaunch` isn't > > accurate: > > > > # @prelaunch: QEMU was started with -S and guest has not started > > > > This is false, as QEMU can be in `prelaunch` state even if -S is > > not used. > > > > > > Also, this is the description you proposed for `preconfig`: > > > > # @preconfig: QEMU is paused before board specific init callback is executed. > > # The state is reachable only if -preconfig CLI option is used. > > # (Since 2.12) > > > > This seems wrong as well: the `prelaunch` state is reachable even > > if `-preconfig` isn't used in the command-line (because it is the > > initial state). > I'm not sure we should describe transitions/initial state here > (it's not the case now). > > I think descriptions 'almost' match 'end' result of what QMP client > cloud see and the initial state is not something that QMP user could > observe. That's my impression as well: `prelaunch` should be visible externally only if `-S` was used, and `preconfig` should be visible externally only if `-preconfig` was used. However, I miss documentation on what are the expectations/requirements internally. e.g. there's no explanation why a reset request moves QEMU to RUN_STATE_PRELAUNCH. Ideally, each line in runstate_transition_def would have a clear explanation for when/why each transition happens. But this isn't a requirement for the new feature you are implementing, anyway. -- Eduardo