Peter Maydell <peter.mayd...@linaro.org> writes:
> Fix one typo in the process and format more option and > command names as literal text, but make no significant > changes to the content. > > Signed-off-by: Peter Maydell <peter.mayd...@linaro.org> > Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> > Message-id: 20200226113034.6741-17-pbonz...@redhat.com Reviewed-by: Alex Bennée <alex.ben...@linaro.org> > --- > docs/system/index.rst | 2 +- > docs/system/managed-startup.rst | 35 +++++++++++++++++++++++++++++++++ > 2 files changed, 36 insertions(+), 1 deletion(-) > create mode 100644 docs/system/managed-startup.rst > > diff --git a/docs/system/index.rst b/docs/system/index.rst > index 5034f903407..d655344fffd 100644 > --- a/docs/system/index.rst > +++ b/docs/system/index.rst > @@ -13,6 +13,6 @@ Contents: > > .. toctree:: > :maxdepth: 2 > - > + managed-startup > security > vfio-ap > diff --git a/docs/system/managed-startup.rst b/docs/system/managed-startup.rst > new file mode 100644 > index 00000000000..9bcf98ea790 > --- /dev/null > +++ b/docs/system/managed-startup.rst > @@ -0,0 +1,35 @@ > +Managed start up options > +======================== > + > +In system mode emulation, it's possible to create a VM in a paused > +state using the ``-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. The VM > +state in this paused state depends on the way QEMU was started. It > +could be in: > + > +- initial state (after reset/power on state) > +- with direct kernel loading, the initial state could be amended to execute > + code loaded by QEMU in the VM's RAM and with incoming migration > +- with incoming migration, initial state will be amended with the migrated > + machine state after migration completes > + > +This paused state is typically used by users to query machine state and/or > +additionally configure the machine (by hotplugging devices) in runtime before > +allowing VM code to run. > + > +However, at the ``-S`` pause point, it's impossible to configure options > +that affect initial VM creation (like: ``-smp``/``-m``/``-numa`` ...) or > +cold plug devices. The experimental ``--preconfig`` command line option > +allows pausing QEMU before the initial VM creation, in a "preconfig" state, > +where additional queries and configuration can be performed via QMP > +before moving on to the resulting configuration startup. 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: > + > +- ``qmp_capabilities`` > +- ``query-qmp-schema`` > +- ``query-commands`` > +- ``query-status`` > +- ``x-exit-preconfig`` -- Alex Bennée
