shutdown: Prepare for use of an enum in reset/shutdown_request

We want to track why a guest was shutdown; in particular, being able
to tell the difference between a guest request (such as ACPI request)
and host request (such as SIGINT) will prove useful to libvirt.
Since all requests eventually end up changing shutdown_requested in
vl.c, the logical change is to make that value track the reason,
rather than its current 0/1 contents.

Since command-line options control whether a reset request is turned
into a shutdown request instead, the same treatment is given to
reset_requested.

This patch adds an internal enum ShutdownCause that describes reasons
that a shutdown can be requested, and changes qemu_system_reset() to
pass the reason through, although for now nothing is actually changed
with regards to what gets reported.  The enum could be exported via
QAPI at a later date, if deemed necessary, but for now, there has not
been a request to expose that much detail to end clients.

For the most part, we turn 0 into SHUTDOWN_CAUSE_NONE, and 1 into
SHUTDOWN_CAUSE_HOST_ERROR; the only specific case where we have enough
information right now to use a different value is when we are reacting
to a host signal.  It will take a further patch to edit all call-sites
that can trigger a reset or shutdown request to properly pass in any
other reasons; this patch includes TODOs to point such places out.

qemu_system_reset() trades its 'bool report' parameter for a
'ShutdownCause reason', with all non-zero values having the same
effect; this lets us get rid of the weird #defines for VMRESET_*
as synonyms for bools.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20170515214114.15442-3-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
This commit is contained in:
Eric Blake 2017-05-15 16:41:11 -05:00 committed by Markus Armbruster
parent 7af88279e4
commit aedbe19297
5 changed files with 58 additions and 29 deletions

View File

@ -1089,11 +1089,14 @@ static void cpu_handle_ioreq(void *opaque)
* causes Xen to powerdown the domain.
*/
if (runstate_is_running()) {
ShutdownCause request;
if (qemu_shutdown_requested_get()) {
destroy_hvm_domain(false);
}
if (qemu_reset_requested_get()) {
qemu_system_reset(VMRESET_REPORT);
request = qemu_reset_requested_get();
if (request) {
qemu_system_reset(request);
destroy_hvm_domain(true);
}
}

View File

@ -33,8 +33,21 @@ VMChangeStateEntry *qemu_add_vm_change_state_handler(VMChangeStateHandler *cb,
void qemu_del_vm_change_state_handler(VMChangeStateEntry *e);
void vm_state_notify(int running, RunState state);
#define VMRESET_SILENT false
#define VMRESET_REPORT true
/* Enumeration of various causes for shutdown. */
typedef enum ShutdownCause {
SHUTDOWN_CAUSE_NONE, /* No shutdown request pending */
SHUTDOWN_CAUSE_HOST_ERROR, /* An error prevents further use of guest */
SHUTDOWN_CAUSE_HOST_QMP, /* Reaction to a QMP command, like 'quit' */
SHUTDOWN_CAUSE_HOST_SIGNAL, /* Reaction to a signal, such as SIGINT */
SHUTDOWN_CAUSE_HOST_UI, /* Reaction to UI event, like window close */
SHUTDOWN_CAUSE_GUEST_SHUTDOWN,/* Guest shutdown/suspend request, via
ACPI or other hardware-specific means */
SHUTDOWN_CAUSE_GUEST_RESET, /* Guest reset request, and command line
turns that into a shutdown */
SHUTDOWN_CAUSE_GUEST_PANIC, /* Guest panicked, and command line turns
that into a shutdown */
SHUTDOWN_CAUSE__MAX,
} ShutdownCause;
void vm_start(void);
int vm_prepare_start(void);
@ -62,10 +75,10 @@ void qemu_system_debug_request(void);
void qemu_system_vmstop_request(RunState reason);
void qemu_system_vmstop_request_prepare(void);
bool qemu_vmstop_requested(RunState *r);
int qemu_shutdown_requested_get(void);
int qemu_reset_requested_get(void);
ShutdownCause qemu_shutdown_requested_get(void);
ShutdownCause qemu_reset_requested_get(void);
void qemu_system_killed(int signal, pid_t pid);
void qemu_system_reset(bool report);
void qemu_system_reset(ShutdownCause reason);
void qemu_system_guest_panicked(GuestPanicInformation *info);
size_t qemu_target_page_size(void);

View File

@ -623,7 +623,7 @@ void *colo_process_incoming_thread(void *opaque)
}
qemu_mutex_lock_iothread();
qemu_system_reset(VMRESET_SILENT);
qemu_system_reset(SHUTDOWN_CAUSE_NONE);
vmstate_loading = true;
if (qemu_loadvm_state(fb) < 0) {
error_report("COLO: loadvm failed");

View File

@ -2285,7 +2285,7 @@ int load_vmstate(const char *name, Error **errp)
return -EINVAL;
}
qemu_system_reset(VMRESET_SILENT);
qemu_system_reset(SHUTDOWN_CAUSE_NONE);
mis->from_src_file = f;
aio_context_acquire(aio_context);

53
vl.c
View File

@ -1597,8 +1597,9 @@ void vm_state_notify(int running, RunState state)
}
}
static int reset_requested;
static int shutdown_requested, shutdown_signal;
static ShutdownCause reset_requested;
static ShutdownCause shutdown_requested;
static int shutdown_signal;
static pid_t shutdown_pid;
static int powerdown_requested;
static int debug_requested;
@ -1612,19 +1613,19 @@ static NotifierList wakeup_notifiers =
NOTIFIER_LIST_INITIALIZER(wakeup_notifiers);
static uint32_t wakeup_reason_mask = ~(1 << QEMU_WAKEUP_REASON_NONE);
int qemu_shutdown_requested_get(void)
ShutdownCause qemu_shutdown_requested_get(void)
{
return shutdown_requested;
}
int qemu_reset_requested_get(void)
ShutdownCause qemu_reset_requested_get(void)
{
return reset_requested;
}
static int qemu_shutdown_requested(void)
{
return atomic_xchg(&shutdown_requested, 0);
return atomic_xchg(&shutdown_requested, SHUTDOWN_CAUSE_NONE);
}
static void qemu_kill_report(void)
@ -1647,14 +1648,15 @@ static void qemu_kill_report(void)
}
}
static int qemu_reset_requested(void)
static ShutdownCause qemu_reset_requested(void)
{
int r = reset_requested;
ShutdownCause r = reset_requested;
if (r && replay_checkpoint(CHECKPOINT_RESET_REQUESTED)) {
reset_requested = 0;
reset_requested = SHUTDOWN_CAUSE_NONE;
return r;
}
return false;
return SHUTDOWN_CAUSE_NONE;
}
static int qemu_suspend_requested(void)
@ -1686,7 +1688,10 @@ static int qemu_debug_requested(void)
return r;
}
void qemu_system_reset(bool report)
/*
* Reset the VM. Issue an event unless @reason is SHUTDOWN_CAUSE_NONE.
*/
void qemu_system_reset(ShutdownCause reason)
{
MachineClass *mc;
@ -1699,7 +1704,8 @@ void qemu_system_reset(bool report)
} else {
qemu_devices_reset();
}
if (report) {
if (reason) {
/* TODO update event based on reason */
qapi_event_send_reset(&error_abort);
}
cpu_synchronize_all_post_reset();
@ -1738,9 +1744,10 @@ void qemu_system_guest_panicked(GuestPanicInformation *info)
void qemu_system_reset_request(void)
{
if (no_reboot) {
shutdown_requested = 1;
/* TODO - add a parameter to allow callers to specify reason */
shutdown_requested = SHUTDOWN_CAUSE_HOST_ERROR;
} else {
reset_requested = 1;
reset_requested = SHUTDOWN_CAUSE_HOST_ERROR;
}
cpu_stop_current();
qemu_notify_event();
@ -1807,7 +1814,7 @@ void qemu_system_killed(int signal, pid_t pid)
/* Cannot call qemu_system_shutdown_request directly because
* we are in a signal handler.
*/
shutdown_requested = 1;
shutdown_requested = SHUTDOWN_CAUSE_HOST_SIGNAL;
qemu_notify_event();
}
@ -1815,7 +1822,8 @@ void qemu_system_shutdown_request(void)
{
trace_qemu_system_shutdown_request();
replay_shutdown_request();
shutdown_requested = 1;
/* TODO - add a parameter to allow callers to specify reason */
shutdown_requested = SHUTDOWN_CAUSE_HOST_ERROR;
qemu_notify_event();
}
@ -1846,14 +1854,18 @@ void qemu_system_debug_request(void)
static bool main_loop_should_exit(void)
{
RunState r;
ShutdownCause request;
if (qemu_debug_requested()) {
vm_stop(RUN_STATE_DEBUG);
}
if (qemu_suspend_requested()) {
qemu_system_suspend();
}
if (qemu_shutdown_requested()) {
request = qemu_shutdown_requested();
if (request) {
qemu_kill_report();
/* TODO update event based on request */
qapi_event_send_shutdown(&error_abort);
if (no_shutdown) {
vm_stop(RUN_STATE_SHUTDOWN);
@ -1861,9 +1873,10 @@ static bool main_loop_should_exit(void)
return true;
}
}
if (qemu_reset_requested()) {
request = qemu_reset_requested();
if (request) {
pause_all_vcpus();
qemu_system_reset(VMRESET_REPORT);
qemu_system_reset(request);
resume_all_vcpus();
if (!runstate_check(RUN_STATE_RUNNING) &&
!runstate_check(RUN_STATE_INMIGRATE)) {
@ -1872,7 +1885,7 @@ static bool main_loop_should_exit(void)
}
if (qemu_wakeup_requested()) {
pause_all_vcpus();
qemu_system_reset(VMRESET_SILENT);
qemu_system_reset(SHUTDOWN_CAUSE_NONE);
notifier_list_notify(&wakeup_notifiers, &wakeup_reason);
wakeup_reason = QEMU_WAKEUP_REASON_NONE;
resume_all_vcpus();
@ -4696,7 +4709,7 @@ int main(int argc, char **argv, char **envp)
reading from the other reads, because timer polling functions query
clock values from the log. */
replay_checkpoint(CHECKPOINT_RESET);
qemu_system_reset(VMRESET_SILENT);
qemu_system_reset(SHUTDOWN_CAUSE_NONE);
register_global_state();
if (replay_mode != REPLAY_MODE_NONE) {
replay_vmstate_init();