On Thu, 26 Apr 2018 09:55:40 -0500
Eric Blake <ebl...@redhat.com> wrote:
> On 04/26/2018 09:39 AM, Igor Mammedov wrote:
>
> >>> I'll try to come up with a text for qemu-doc.texi, not about
> >>> deprecating -S but about when --preconfig should be used vs -S
> >>> and where to get list of commands that could be used at preconfig state.
> >>>
> >>
> >> Sounds good to me. Thanks!
> > how about something like this:
> >
> > diff --git a/qemu-tech.texi b/qemu-tech.texi
> > index 52a56ae..6951258 100644
> > --- a/qemu-tech.texi
> > +++ b/qemu-tech.texi
> > @@ -5,6 +5,7 @@
> > * CPU emulation::
> > * Translator Internals::
> > * QEMU compared to other emulators::
> > +* Managed start up options::
> > * Bibliography::
> > @end menu
> >
> > @@ -314,6 +315,44 @@ VirtualBox [9], Xen [10] and KVM [11] are based on
> > QEMU. QEMU-SystemC
> > [12] uses QEMU to simulate a system where some hardware devices are
> > developed in SystemC.
> >
> > +@node Managed start up options
> > +@section Managed start up options
> > +
> > +In system mode emulation, it's possible to create VM in paused state using
> > +-S command line option. In this state the machine is completely initialized
> > +according to command line options and ready to execute VM code but VCPU
> > threads
> > +are not executing any code. VM state in this paused state depends on way
> > QEMU
> > +was started. It could be in:
> > +@table @asis
> > +@item initial state (after reset/power on state)
> > +@item with direct kernel loading initial state could be ammended to
> > execute
>
> s/ammended/amended/
>
> > +code loaded by QEMU in VM's RAM and with incomming migration
>
> s/incomming/incoming/
>
> > +@item with incomming migrartion, initial state will by ammended by the
> > migrated
>
> and again, for both words
> s/migrartion/migration/
>
> > +machine state after migration completes.
> > +@end table
> > +
> > +This paused state is typically used by users to query machine state and/or
> > +additionally configure machine (hotplug devices) in runtime before allowing
> > +VM code to run.
> > +
> > +However at -S pause point it's impossible to configure options that affect
> > +initial VM creation (like: -smp/-m/-numa ...) or cold plug devices. That's
> > +when -preconfig command line option should be used. It allows to pause
>
> s/to pause/pausing/
>
> > +QEMU before initial VM creation in preconfig state, query being created
> > +VM at runtime and configure start up options depending on previous query
>
> Reads awkwardly. Maybe:
>
> It allows pausing QEMU before the initial VM creation, in a new
> preconfig state, where additional queries and configuration can be
> performed via QMP before moving on to the resulting configuration startup.
>
> > +results. In preconfig state QEMU allows to configure VM only via QMP
> > monitor
> > +with a limited command set which doesn't depend on completely initialized
> > +machine, which includes but not limited to:
>
> In the preconfig state, QEMU only allows a limited set of commands over
> the QMP monitor, where the commands do not depend on an initialized
> machine, including but not limited to:
thanks for review,
I amended patches as you suggested.
I plan to respin v6 today with these changes since exit-preconfig
affected several patches in series.
>
> > +@table @asis
> > +@item qmp_capabilities
> > +@item query-qmp-schema
> > +@item query-commands
> > +@item query-status
> > +@end table
> > +The full list of commands is in QMP schema which could be queried with
> > +query-qmp-schema, where commands supported at preconfig state have option
> > +'allowed-in-preconfig' set to true.
> > +
> > @node Bibliography
> > @section Bibliography
> >
>
> >> A separate command would have less room for ambiguity.
> > I've added following instead of reusing 'cont':
> >
> > ##
> >
> > # @exit-preconfig:
> >
>
> This should definitely be mentioned in the docs section of commands
> permitted during preconfig.
done
>
> > #
> >
> > # Exit from "preconfig" state
> >
> > #
> >
> > # Since 2.13
> >
> > #
> >
> > # Returns: nothing
> >
> > #
> >
> > # Notes: Command makes QEMU exit from preconfig state and proceeds with
> >
> > # VM initialization using configuration data provided on command line
> >
> > # and via QMP monitor at preconfig state. Command is available only at
> >
> > # preconfig state (i.e. if --preconfig command line option).
> >
> > #
> >
> > # Example:
> >
> > #
> >
> > # -> { "execute": "exit-preconfig" }
> >
> > # <- { "return": {} }
> >
> > #
> >
> > ##
> >
> > { 'command': 'exit-preconfig', 'allowed-in-preconfig': true }
> >
> >
>
