qemu: add config to control if auto-shutdown VMs are restored

If shutting down running VMs at host shutdown, it can be useful to
automatically start them again on next boot. This adds a config
parameter 'auto_shutdown_restore', which defaults to enabled, which
leverages the autostart once feature.

Reviewed-by: Peter Krempa <pkrempa@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

src/qemu/libvirtd_qemu.aug

@@ -107,6 +107,7 @@ module Libvirtd_qemu =
                  | str_entry "auto_shutdown_try_shutdown"
                  | str_entry "auto_shutdown_poweroff"
                  | int_entry "auto_shutdown_wait"
+                 | bool_entry "auto_shutdown_restore"
                  | bool_entry "auto_save_bypass_cache"
 
    let process_entry = str_entry "hugetlbfs_mount"

src/qemu/qemu.conf.in

@@ -714,6 +714,10 @@
 # is currently 30 secs)
 #auto_shutdown_wait = 30
 
+# Whether VMs that are automatically powered off or saved during
+# host shutdown, should be set to restore on next boot
+#auto_shutdown_restore = 1
+
 # When a domain is configured to be auto-saved on shutdown, enabling
 # this flag has the same effect as using the VIR_DOMAIN_SAVE_BYPASS_CACHE
 # flag with the virDomainManagedSave API.  That is, the system will

src/qemu/qemu_conf.c

@@ -328,6 +328,7 @@ virQEMUDriverConfig *virQEMUDriverConfigNew(bool privileged,
         cfg->autoShutdownTryShutdown = VIR_DOMAIN_DRIVER_AUTO_SHUTDOWN_SCOPE_ALL;
         cfg->autoShutdownPoweroff = VIR_DOMAIN_DRIVER_AUTO_SHUTDOWN_SCOPE_ALL;
     }
+    cfg->autoShutdownRestore = true;
 
     return g_steal_pointer(&cfg);
 }
@@ -766,6 +767,8 @@ virQEMUDriverConfigLoadSaveEntry(virQEMUDriverConfig *cfg,
     if (virConfGetValueUInt(conf, "auto_shutdown_wait",
                             &cfg->autoShutdownWait) < 0)
         return -1;
+    if (virConfGetValueBool(conf, "auto_shutdown_restore", &cfg->autoShutdownRestore) < 0)
+        return -1;
     if (virConfGetValueBool(conf, "auto_save_bypass_cache",
                             &cfg->autoSaveBypassCache) < 0)
         return -1;

src/qemu/qemu_conf.h

@@ -216,6 +216,7 @@ struct _virQEMUDriverConfig {
     virDomainDriverAutoShutdownScope autoShutdownTryShutdown;
     virDomainDriverAutoShutdownScope autoShutdownPoweroff;
     unsigned int autoShutdownWait;
+    bool autoShutdownRestore;
     bool autoSaveBypassCache;
 
     char *lockManagerName;

src/qemu/qemu_driver.c

@@ -971,6 +971,7 @@ qemuStateStop(void)
         .poweroff = cfg->autoShutdownPoweroff,
         .waitShutdownSecs = cfg->autoShutdownWait,
         .saveBypassCache = cfg->autoSaveBypassCache,
+        .autoRestore = cfg->autoShutdownRestore,
     };
 
     virDomainDriverAutoShutdown(&ascfg);

src/qemu/test_libvirtd_qemu.aug.in

@@ -84,6 +84,7 @@ module Test_libvirtd_qemu =
 { "auto_shutdown_try_shutdown" = "all" }
 { "auto_shutdown_poweroff" = "all" }
 { "auto_shutdown_wait" = "30" }
+{ "auto_shutdown_restore" = "1" }
 { "auto_save_bypass_cache" = "0" }
 { "hugetlbfs_mount" = "/dev/hugepages" }
 { "bridge_helper" = "qemu-bridge-helper" }