diff options
| -rw-r--r-- | include/sysemu/sysemu.h | 1 | ||||
| -rw-r--r-- | qapi/misc.json | 23 | ||||
| -rw-r--r-- | qapi/qmp-dispatch.c | 8 | ||||
| -rw-r--r-- | qemu-options.hx | 13 | ||||
| -rw-r--r-- | qemu-tech.texi | 40 | ||||
| -rw-r--r-- | qmp.c | 10 | ||||
| -rw-r--r-- | vl.c | 35 |
7 files changed, 129 insertions, 1 deletions
diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h index 544ab77a2b..e893f72f3b 100644 --- a/include/sysemu/sysemu.h +++ b/include/sysemu/sysemu.h @@ -66,6 +66,7 @@ typedef enum WakeupReason { QEMU_WAKEUP_REASON_OTHER, } WakeupReason; +void qemu_exit_preconfig_request(void); void qemu_system_reset_request(ShutdownCause reason); void qemu_system_suspend_request(void); void qemu_register_suspend_notifier(Notifier *notifier); diff --git a/qapi/misc.json b/qapi/misc.json index ae2bb27b83..bd6d1805ab 100644 --- a/qapi/misc.json +++ b/qapi/misc.json @@ -1245,6 +1245,29 @@ { 'command': 'cont' } ## +# @exit-preconfig: +# +# Exit from "preconfig" state +# +# This command makes QEMU exit the preconfig state and proceed with +# VM initialization using configuration data provided on the command line +# and via the QMP monitor during the preconfig state. The command is only +# available during the preconfig state (i.e. when the --preconfig command +# line option was in use). +# +# Since 3.0 +# +# Returns: nothing +# +# Example: +# +# -> { "execute": "exit-preconfig" } +# <- { "return": {} } +# +## +{ 'command': 'exit-preconfig', 'allow-preconfig': true } + +## # @system_wakeup: # # Wakeup guest from suspend. Does nothing in case the guest isn't suspended. diff --git a/qapi/qmp-dispatch.c b/qapi/qmp-dispatch.c index f9377b27fd..935f9e159c 100644 --- a/qapi/qmp-dispatch.c +++ b/qapi/qmp-dispatch.c @@ -18,6 +18,7 @@ #include "qapi/qmp/qdict.h" #include "qapi/qmp/qjson.h" #include "qapi/qmp/qbool.h" +#include "sysemu/sysemu.h" QDict *qmp_dispatch_check_obj(const QObject *request, Error **errp) { @@ -101,6 +102,13 @@ static QObject *do_qmp_dispatch(QmpCommandList *cmds, QObject *request, return NULL; } + if (runstate_check(RUN_STATE_PRECONFIG) && + !(cmd->options & QCO_ALLOW_PRECONFIG)) { + error_setg(errp, "The command '%s' isn't permitted in '%s' state", + cmd->name, RunState_str(RUN_STATE_PRECONFIG)); + return NULL; + } + if (!qdict_haskey(dict, "arguments")) { args = qdict_new(); } else { diff --git a/qemu-options.hx b/qemu-options.hx index abbfa6ae9e..2f61ea42ee 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -3299,6 +3299,19 @@ STEXI Run the emulation in single step mode. ETEXI +DEF("preconfig", 0, QEMU_OPTION_preconfig, \ + "--preconfig pause QEMU before machine is initialized\n", + QEMU_ARCH_ALL) +STEXI +@item --preconfig +@findex --preconfig +Pause QEMU for interactive configuration before the machine is created, +which allows querying and configuring properties that will affect +machine initialization. Use the QMP command 'exit-preconfig' to exit +the preconfig state and move to the next state (ie. run guest if -S +isn't used or pause the second time if -S is used). +ETEXI + DEF("S", 0, QEMU_OPTION_S, \ "-S freeze CPU at startup (use 'c' to start execution)\n", QEMU_ARCH_ALL) diff --git a/qemu-tech.texi b/qemu-tech.texi index 52a56ae25e..dcecba83cb 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 +315,45 @@ 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 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: +@table @asis +@item initial state (after reset/power on state) +@item 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 +@item with incoming migration, initial state will by amended with the migrated +machine state after migration completes. +@end table + +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. That's +when the --preconfig command line option should be used. 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. 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: +@table @asis +@item qmp_capabilities +@item query-qmp-schema +@item query-commands +@item query-status +@item exit-preconfig +@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 +'allow-preconfig' set to true. + @node Bibliography @section Bibliography diff --git a/qmp.c b/qmp.c index 25fdc9a5b2..73e46d795f 100644 --- a/qmp.c +++ b/qmp.c @@ -161,6 +161,16 @@ SpiceInfo *qmp_query_spice(Error **errp) }; #endif +void qmp_exit_preconfig(Error **errp) +{ + if (!runstate_check(RUN_STATE_PRECONFIG)) { + error_setg(errp, "The command is permitted only in '%s' state", + RunState_str(RUN_STATE_PRECONFIG)); + return; + } + qemu_exit_preconfig_request(); +} + void qmp_cont(Error **errp) { BlockBackend *blk; diff --git a/vl.c b/vl.c index 038d7f8042..c4fe25560c 100644 --- a/vl.c +++ b/vl.c @@ -594,7 +594,7 @@ static int default_driver_check(void *opaque, QemuOpts *opts, Error **errp) /***********************************************************/ /* QEMU state */ -static RunState current_run_state = RUN_STATE_PRELAUNCH; +static RunState current_run_state = RUN_STATE_PRECONFIG; /* We use RUN_STATE__MAX but any invalid value will do */ static RunState vmstop_requested = RUN_STATE__MAX; @@ -607,6 +607,13 @@ typedef struct { static const RunStateTransition runstate_transitions_def[] = { /* from -> to */ + { RUN_STATE_PRECONFIG, RUN_STATE_PRELAUNCH }, + /* Early switch to inmigrate state to allow -incoming CLI option work + * as it used to. TODO: delay actual switching to inmigrate state to + * the point after machine is built and remove this hack. + */ + { RUN_STATE_PRECONFIG, RUN_STATE_INMIGRATE }, + { RUN_STATE_DEBUG, RUN_STATE_RUNNING }, { RUN_STATE_DEBUG, RUN_STATE_FINISH_MIGRATE }, { RUN_STATE_DEBUG, RUN_STATE_PRELAUNCH }, @@ -1630,6 +1637,7 @@ static pid_t shutdown_pid; static int powerdown_requested; static int debug_requested; static int suspend_requested; +static bool preconfig_exit_requested = true; static WakeupReason wakeup_reason; static NotifierList powerdown_notifiers = NOTIFIER_LIST_INITIALIZER(powerdown_notifiers); @@ -1714,6 +1722,11 @@ static int qemu_debug_requested(void) return r; } +void qemu_exit_preconfig_request(void) +{ + preconfig_exit_requested = true; +} + /* * Reset the VM. Issue an event unless @reason is SHUTDOWN_CAUSE_NONE. */ @@ -1887,6 +1900,13 @@ static bool main_loop_should_exit(void) RunState r; ShutdownCause request; + if (preconfig_exit_requested) { + if (runstate_check(RUN_STATE_PRECONFIG)) { + runstate_set(RUN_STATE_PRELAUNCH); + } + preconfig_exit_requested = false; + return true; + } if (qemu_debug_requested()) { vm_stop(RUN_STATE_DEBUG); } @@ -3667,6 +3687,9 @@ int main(int argc, char **argv, char **envp) exit(1); } break; + case QEMU_OPTION_preconfig: + preconfig_exit_requested = false; + break; case QEMU_OPTION_enable_kvm: olist = qemu_find_opts("machine"); qemu_opts_parse_noisily(olist, "accel=kvm", false); @@ -4031,6 +4054,12 @@ int main(int argc, char **argv, char **envp) replay_configure(icount_opts); + if (incoming && !preconfig_exit_requested) { + error_report("'preconfig' and 'incoming' options are " + "mutually exclusive"); + exit(EXIT_FAILURE); + } + machine_class = select_machine(); set_memory_options(&ram_slots, &maxram_size, machine_class); @@ -4548,6 +4577,10 @@ int main(int argc, char **argv, char **envp) } parse_numa_opts(current_machine); + /* do monitor/qmp handling at preconfig state if requested */ + main_loop(); + + /* from here on runstate is RUN_STATE_PRELAUNCH */ machine_run_board_init(current_machine); realtime_init(); |