machine: Add wakeup method to MachineClass

Waking from suspend is not logically a machine reset on all machines,
particularly in the paravirtualized case rather than hardware
emulated. The ppc spapr machine for example just invokes hypervisor
to suspend, and expects that call to return with the machine in the
same state (modulo some possible migration and reconfiguration
details).

Implement a machine ->wakeup method and use that if it exists.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-Id: <20190722053215.20808-2-npiggin@gmail.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

diff --git a/include/hw/boards.h b/include/hw/boards.h
index aa35955f7fa79620fa4bf237fc8340ce382bfada..60d69217b494d078a32d91807df0d139f632d686 100644 (file)
--- a/include/hw/boards.h
+++ b/include/hw/boards.h
@@ -180,6 +180,7 @@ struct MachineClass {
 
     void (*init)(MachineState *state);
     void (*reset)(MachineState *state);
+    void (*wakeup)(MachineState *state);
     void (*hot_add_cpu)(MachineState *state, const int64_t id, Error **errp);
     int (*kvm_type)(MachineState *machine, const char *arg);
     void (*smp_parse)(MachineState *ms, QemuOpts *opts);

diff --git a/vl.c b/vl.c
index edd5390110b273fb401261ed7615bf1a4aad0f71..09aa18cb350488267d36cd1c4d70ce5b566cf13e 100644 (file)
--- a/vl.c
+++ b/vl.c
@@ -1557,6 +1557,22 @@ void qemu_system_reset(ShutdownCause reason)
     cpu_synchronize_all_post_reset();
 }
 
+/*
+ * Wake the VM after suspend.
+ */
+static void qemu_system_wakeup(void)
+{
+    MachineClass *mc;
+
+    mc = current_machine ? MACHINE_GET_CLASS(current_machine) : NULL;
+
+    if (mc && mc->wakeup) {
+        mc->wakeup(current_machine);
+    } else {
+        qemu_system_reset(SHUTDOWN_CAUSE_NONE);
+    }
+}
+
 void qemu_system_guest_panicked(GuestPanicInformation *info)
 {
     qemu_log_mask(LOG_GUEST_ERROR, "Guest crashed");
@@ -1765,7 +1781,7 @@ static bool main_loop_should_exit(void)
     }
     if (qemu_wakeup_requested()) {
         pause_all_vcpus();
-        qemu_system_reset(SHUTDOWN_CAUSE_NONE);
+        qemu_system_wakeup();
         notifier_list_notify(&wakeup_notifiers, &wakeup_reason);
         wakeup_reason = QEMU_WAKEUP_REASON_NONE;
         resume_all_vcpus();