From 2b77727b356747ab6b91af0400f4a6f1a7d36a40 Mon Sep 17 00:00:00 2001

From: Eric Blake <eblake@redhat.com>

Date: Thu, 1 Jun 2017 16:58:18 +0200

Subject: [PATCH 02/17] shutdown: Prepare for use of an enum in

 reset/shutdown_request

RH-Author: Eric Blake <eblake@redhat.com>

Message-id: <20170601165821.26810-3-eblake@redhat.com>

Patchwork-id: 75465

O-Subject: [RHEL-7.4 qemu-kvm-rhev PATCH v2 2/5] shutdown: Prepare for use of an enum in reset/shutdown_request

Bugzilla: 1418927

RH-Acked-by: John Snow <jsnow@redhat.com>

RH-Acked-by: Markus Armbruster <armbru@redhat.com>

RH-Acked-by: Thomas Huth <thuth@redhat.com>

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>

(cherry picked from commit aedbe19297907143f17b733a7ff0e0534377bed1)

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>

---

 include/sysemu/sysemu.h | 23 ++++++++++++++++-----

 migration/colo.c        |  2 +-

 migration/savevm.c      |  2 +-

 vl.c                    | 53 ++++++++++++++++++++++++++++++-------------------

 xen-hvm.c               |  7 +++++--

 5 files changed, 58 insertions(+), 29 deletions(-)

diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h

index 1fd51a8..f942562 100644

--- a/include/sysemu/sysemu.h

+++ b/include/sysemu/sysemu.h

@@ -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_bits(void);

diff --git a/migration/colo.c b/migration/colo.c

index 963c802..12d355a 100644

--- a/migration/colo.c

+++ b/migration/colo.c

@@ -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");

diff --git a/migration/savevm.c b/migration/savevm.c

index 6e2f9e7..483c05f 100644

--- a/migration/savevm.c

+++ b/migration/savevm.c

@@ -2368,7 +2368,7 @@ int load_vmstate(const char *name)

         return -EINVAL;

     }

-    qemu_system_reset(VMRESET_SILENT);

+    qemu_system_reset(SHUTDOWN_CAUSE_NONE);

     mis->from_src_file = f;

     aio_context_acquire(aio_context);

diff --git a/vl.c b/vl.c

index f5dea2c..ea181c6 100644

--- a/vl.c

+++ b/vl.c

@@ -1596,8 +1596,9 @@ 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;

@@ -1611,19 +1612,19 @@ 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)

@@ -1646,14 +1647,15 @@ 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)

@@ -1685,7 +1687,10 @@ 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;

@@ -1698,7 +1703,8 @@ 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();

@@ -1737,9 +1743,10 @@ 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();

@@ -1806,7 +1813,7 @@ 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();

 }

@@ -1814,7 +1821,8 @@ 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();

 }

@@ -1845,14 +1853,18 @@ 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);

@@ -1860,9 +1872,10 @@ 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)) {

@@ -1871,7 +1884,7 @@ 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();

@@ -4689,7 +4702,7 @@ 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();

diff --git a/xen-hvm.c b/xen-hvm.c

index 5043beb..858e934 100644

--- a/xen-hvm.c

+++ b/xen-hvm.c

@@ -1090,11 +1090,14 @@ 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);

             }

         }

-- 

1.8.3.1