diff mbox series

[7/7] spice: Call qemu spice functions indirectly

Message ID 20200723174615.2370096-8-dinechin@redhat.com (mailing list archive)
State New, archived
Headers show
Series Make SPICE a load module | expand

Commit Message

Christophe de Dinechin July 23, 2020, 5:46 p.m. UTC
In order to be able to move all of spice in a shared library that is
loaded dynamically only on demand, this commit puts the functions
called by the main binary in a QemuSpiceOps structure, and use static
inline stubs to preserve the call sites.

With these changes, the following shared libraries are no longer
necessary in the top-level qemu binary when building with CONFIG_MDULES:

        libspice-server.so.1 => /lib64/libspice-server.so.1 (HEX)
        libopus.so.0 => /lib64/libopus.so.0 (HEX)
        liblz4.so.1 => /lib64/liblz4.so.1 (HEX)
        libgstapp-1.0.so.0 => /lib64/libgstapp-1.0.so.0 (HEX)
        libgstvideo-1.0.so.0 => /lib64/libgstvideo-1.0.so.0 (HEX)
        libgstbase-1.0.so.0 => /lib64/libgstbase-1.0.so.0 (HEX)
        libgstreamer-1.0.so.0 => /lib64/libgstreamer-1.0.so.0 (HEX)
        libssl.so.1.1 => /lib64/libssl.so.1.1 (HEX)
        liborc-0.4.so.0 => /lib64/liborc-0.4.so.0 (HEX)

Signed-off-by: Christophe de Dinechin <dinechin@redhat.com>
---
 include/ui/qemu-spice.h | 74 +++++++++++++++++++----------------------
 monitor/hmp-cmds.c      | 13 ++++++++
 monitor/misc.c          |  2 +-
 monitor/qmp-cmds.c      |  6 ++--
 softmmu/vl.c            | 28 ++++++++++++++--
 ui/spice-core.c         | 33 ++++++++++++++++--
 6 files changed, 107 insertions(+), 49 deletions(-)

Comments

Dr. David Alan Gilbert July 27, 2020, 5:38 p.m. UTC | #1
* Christophe de Dinechin (dinechin@redhat.com) wrote:
> In order to be able to move all of spice in a shared library that is
> loaded dynamically only on demand, this commit puts the functions
> called by the main binary in a QemuSpiceOps structure, and use static
> inline stubs to preserve the call sites.
> 
> With these changes, the following shared libraries are no longer
> necessary in the top-level qemu binary when building with CONFIG_MDULES:
> 
>         libspice-server.so.1 => /lib64/libspice-server.so.1 (HEX)
>         libopus.so.0 => /lib64/libopus.so.0 (HEX)
>         liblz4.so.1 => /lib64/liblz4.so.1 (HEX)
>         libgstapp-1.0.so.0 => /lib64/libgstapp-1.0.so.0 (HEX)
>         libgstvideo-1.0.so.0 => /lib64/libgstvideo-1.0.so.0 (HEX)
>         libgstbase-1.0.so.0 => /lib64/libgstbase-1.0.so.0 (HEX)
>         libgstreamer-1.0.so.0 => /lib64/libgstreamer-1.0.so.0 (HEX)
>         libssl.so.1.1 => /lib64/libssl.so.1.1 (HEX)
>         liborc-0.4.so.0 => /lib64/liborc-0.4.so.0 (HEX)
> 
> Signed-off-by: Christophe de Dinechin <dinechin@redhat.com>
> ---
>  include/ui/qemu-spice.h | 74 +++++++++++++++++++----------------------
>  monitor/hmp-cmds.c      | 13 ++++++++
>  monitor/misc.c          |  2 +-
>  monitor/qmp-cmds.c      |  6 ++--
>  softmmu/vl.c            | 28 ++++++++++++++--
>  ui/spice-core.c         | 33 ++++++++++++++++--
>  6 files changed, 107 insertions(+), 49 deletions(-)
> 
> diff --git a/include/ui/qemu-spice.h b/include/ui/qemu-spice.h
> index d34cea2e0f..9721d8817e 100644
> --- a/include/ui/qemu-spice.h
> +++ b/include/ui/qemu-spice.h
> @@ -25,21 +25,28 @@
>  #include <spice.h>
>  #include "qemu/config-file.h"
>  
> -extern int using_spice;
> +#define using_spice     (qemu_spice.in_use())
>  
> -void qemu_spice_init(void);
>  void qemu_spice_input_init(void);
>  void qemu_spice_audio_init(void);
> -void qemu_spice_display_init(void);
> -int qemu_spice_display_add_client(int csock, int skipauth, int tls);
>  int qemu_spice_add_interface(SpiceBaseInstance *sin);
>  bool qemu_spice_have_display_interface(QemuConsole *con);
>  int qemu_spice_add_display_interface(QXLInstance *qxlin, QemuConsole *con);
> +
> +#if !defined(CONFIG_MODULES) || defined(BUILD_DSO)
> +bool qemu_is_using_spice(void);
> +void qemu_start_using_spice(void);
> +void qemu_spice_init(void);
> +void qemu_spice_display_init(void);
> +int qemu_spice_display_add_client(int csock, int skipauth, int tls);
>  int qemu_spice_set_passwd(const char *passwd,
>                            bool fail_if_connected, bool disconnect_if_connected);
>  int qemu_spice_set_pw_expire(time_t expires);
>  int qemu_spice_migrate_info(const char *hostname, int port, int tls_port,
>                              const char *subject);
> +struct SpiceInfo *qemu_spice_query(Error **errp);
> +#endif /* !CONFIG_MODULES || BUILD_DSO */
> +
>  
>  #if !defined(SPICE_SERVER_VERSION) || (SPICE_SERVER_VERSION < 0xc06)
>  #define SPICE_NEEDS_SET_MM_TIME 1
> @@ -47,46 +54,33 @@ int qemu_spice_migrate_info(const char *hostname, int port, int tls_port,
>  #define SPICE_NEEDS_SET_MM_TIME 0
>  #endif
>  
> -#else  /* CONFIG_SPICE */
> -
> -#include "qemu/error-report.h"
> -
> -#define using_spice 0
> -#define spice_displays 0
> -static inline int qemu_spice_set_passwd(const char *passwd,
> -                                        bool fail_if_connected,
> -                                        bool disconnect_if_connected)
> -{
> -    return -1;
> -}
> -static inline int qemu_spice_set_pw_expire(time_t expires)
> -{
> -    return -1;
> -}
> -static inline int qemu_spice_migrate_info(const char *h, int p, int t,
> -                                          const char *s)
> -{
> -    return -1;
> -}
> +#else /* !CONFIG_SPICE */
>  
> -static inline int qemu_spice_display_add_client(int csock, int skipauth,
> -                                                int tls)
> -{
> -    return -1;
> -}
> +#define using_spice     0
>  
> -static inline void qemu_spice_display_init(void)
> -{
> -    /* This must never be called if CONFIG_SPICE is disabled */
> -    error_report("spice support is disabled");
> -    abort();
> -}
> +#endif /* CONFIG_SPICE */
>  
> -static inline void qemu_spice_init(void)
> +/* Module high-level inteface for SPICE */
> +struct QemuSpiceOps
>  {
> -}
> -
> -#endif /* CONFIG_SPICE */
> +    bool (*in_use)(void);
> +    void (*init)(void);
> +    void (*display_init)(void);
> +    int (*display_add_client)(int csock, int skipauth, int tls);
> +
> +    int (*set_passwd)(const char *passwd,
> +                      bool fail_if_connected,
> +                      bool disconnect_if_connected);
> +    int (*set_pw_expire)(time_t expires);
> +    int (*migrate_info)(const char *hostname,
> +                        int port, int tls_port,
> +                        const char *subject);
> +    struct SpiceInfo * (*query)(Error **errp);
> +};
> +typedef struct QemuSpiceOps QemuSpiceOps;
> +void qemu_spice_ops_register(QemuSpiceOps *ops);
> +
> +extern struct QemuSpiceOps qemu_spice;
>  
>  static inline bool qemu_using_spice(Error **errp)
>  {
> diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
> index ae4b6a4246..8e10af188f 100644
> --- a/monitor/hmp-cmds.c
> +++ b/monitor/hmp-cmds.c
> @@ -57,6 +57,7 @@
>  
>  #ifdef CONFIG_SPICE
>  #include <spice/enums.h>
> +#include "ui/qemu-spice.h"
>  #endif
>  
>  void hmp_handle_error(Monitor *mon, Error *err)
> @@ -573,6 +574,14 @@ void hmp_info_vnc(Monitor *mon, const QDict *qdict)
>  #endif
>  
>  #ifdef CONFIG_SPICE
> +SpiceInfo *qmp_query_spice(Error **errp)
> +{
> +    if (!using_spice) {
> +        return NULL;
> +    }
> +    return qemu_spice.query(errp);
> +}
> +

It's a bit weird to put the qmp function in the hmp file.

>  void hmp_info_spice(Monitor *mon, const QDict *qdict)
>  {
>      SpiceChannelList *chan;
> @@ -599,6 +608,10 @@ void hmp_info_spice(Monitor *mon, const QDict *qdict)
>  
>      info = qmp_query_spice(NULL);
>  
> +    if (!info) {
> +        monitor_printf(mon, "Server: not started\n");
> +        goto out;
> +    }
>      if (!info->enabled) {
>          monitor_printf(mon, "Server: disabled\n");
>          goto out;

Dave

> diff --git a/monitor/misc.c b/monitor/misc.c
> index e847b58a8c..88f8915734 100644
> --- a/monitor/misc.c
> +++ b/monitor/misc.c
> @@ -443,7 +443,7 @@ void qmp_client_migrate_info(const char *protocol, const char *hostname,
>              return;
>          }
>  
> -        if (qemu_spice_migrate_info(hostname,
> +        if (qemu_spice.migrate_info(hostname,
>                                      has_port ? port : -1,
>                                      has_tls_port ? tls_port : -1,
>                                      cert_subject)) {
> diff --git a/monitor/qmp-cmds.c b/monitor/qmp-cmds.c
> index 864cbfa32e..9f9822b3f3 100644
> --- a/monitor/qmp-cmds.c
> +++ b/monitor/qmp-cmds.c
> @@ -196,7 +196,7 @@ void qmp_set_password(const char *protocol, const char *password,
>          if (!qemu_using_spice(errp)) {
>              return;
>          }
> -        rc = qemu_spice_set_passwd(password, fail_if_connected,
> +        rc = qemu_spice.set_passwd(password, fail_if_connected,
>                                     disconnect_if_connected);
>          if (rc != 0) {
>              error_setg(errp, QERR_SET_PASSWD_FAILED);
> @@ -242,7 +242,7 @@ void qmp_expire_password(const char *protocol, const char *whenstr,
>          if (!qemu_using_spice(errp)) {
>              return;
>          }
> -        rc = qemu_spice_set_pw_expire(when);
> +        rc = qemu_spice.set_pw_expire(when);
>          if (rc != 0) {
>              error_setg(errp, QERR_SET_PASSWD_FAILED);
>          }
> @@ -339,7 +339,7 @@ void qmp_add_client(const char *protocol, const char *fdname,
>          }
>          skipauth = has_skipauth ? skipauth : false;
>          tls = has_tls ? tls : false;
> -        if (qemu_spice_display_add_client(fd, skipauth, tls) < 0) {
> +        if (qemu_spice.display_add_client(fd, skipauth, tls) < 0) {
>              error_setg(errp, "spice failed to add client");
>              close(fd);
>          }
> diff --git a/softmmu/vl.c b/softmmu/vl.c
> index bc0dcc4f58..8defda56c9 100644
> --- a/softmmu/vl.c
> +++ b/softmmu/vl.c
> @@ -173,6 +173,30 @@ int icount_align_option;
>  QemuUUID qemu_uuid;
>  bool qemu_uuid_set;
>  
> +static bool qemu_is_not_using_spice(void)
> +{
> +    return 0;
> +}
> +
> +static void qemu_spice_init_no_op(void)
> +{
> +}
> +
> +/*
> + * Only two fields are initialized, that can be used even when SPICE
> + * is not configured or not loaded. Other functions are protected by
> + * checking if using_spice.
> + */
> +QemuSpiceOps qemu_spice = {
> +    .in_use             = qemu_is_not_using_spice,
> +    .init               = qemu_spice_init_no_op,
> +};
> +
> +void qemu_spice_ops_register(QemuSpiceOps *ops)
> +{
> +    memcpy(&qemu_spice, ops, sizeof(qemu_spice));
> +}
> +
>  static NotifierList exit_notifiers =
>      NOTIFIER_LIST_INITIALIZER(exit_notifiers);
>  
> @@ -4128,7 +4152,7 @@ void qemu_init(int argc, char **argv, char **envp)
>      /* spice needs the timers to be initialized by this point */
>      /* spice must initialize before audio as it changes the default auiodev */
>      /* spice must initialize before chardevs (for spicevmc and spiceport) */
> -    qemu_spice_init();
> +    qemu_spice.init();
>  
>      qemu_opts_foreach(qemu_find_opts("object"),
>                        user_creatable_add_opts_foreach,
> @@ -4424,7 +4448,7 @@ void qemu_init(int argc, char **argv, char **envp)
>  #endif
>  
>      if (using_spice) {
> -        qemu_spice_display_init();
> +        qemu_spice.display_init();
>      }
>  
>      if (foreach_device_config(DEV_GDB, gdbserver_start) < 0) {
> diff --git a/ui/spice-core.c b/ui/spice-core.c
> index 37dd68f2ab..9d7ac70d92 100644
> --- a/ui/spice-core.c
> +++ b/ui/spice-core.c
> @@ -48,7 +48,7 @@ static time_t auth_expires = TIME_MAX;
>  static int spice_migration_completed;
>  static int spice_display_is_running;
>  static int spice_have_target_host;
> -int using_spice = 0;
> +static int is_using_spice;
>  
>  static QemuThread me;
>  
> @@ -503,7 +503,7 @@ static QemuOptsList qemu_spice_opts = {
>      },
>  };
>  
> -SpiceInfo *qmp_query_spice(Error **errp)
> +SpiceInfo *qemu_spice_query(Error **errp)
>  {
>      QemuOpts *opts = QTAILQ_FIRST(&qemu_spice_opts.head);
>      int port, tls_port;
> @@ -634,6 +634,16 @@ static void vm_change_state_handler(void *opaque, int running,
>      }
>  }
>  
> +bool qemu_is_using_spice(void)
> +{
> +    return is_using_spice;
> +}
> +
> +void qemu_start_using_spice(void)
> +{
> +    is_using_spice = 1;
> +}
> +
>  void qemu_spice_init(void)
>  {
>      QemuOpts *opts = QTAILQ_FIRST(&qemu_spice_opts.head);
> @@ -796,7 +806,7 @@ void qemu_spice_init(void)
>          error_report("failed to initialize spice server");
>          exit(1);
>      };
> -    using_spice = 1;
> +    qemu_start_using_spice();
>  
>      migration_state.notify = migration_state_notifier;
>      add_migration_state_change_notifier(&migration_state);
> @@ -1000,3 +1010,20 @@ static void spice_register_config(void)
>      qemu_add_opts(&qemu_spice_opts);
>  }
>  opts_init(spice_register_config);
> +
> +static QemuSpiceOps qemu_spice_ops = {
> +    .in_use             = qemu_is_using_spice,
> +    .init               = qemu_spice_init,
> +    .display_init       = qemu_spice_display_init,
> +    .display_add_client = qemu_spice_display_add_client,
> +    .set_passwd         = qemu_spice_set_passwd,
> +    .set_pw_expire      = qemu_spice_set_pw_expire,
> +    .migrate_info       = qemu_spice_migrate_info,
> +    .query              = qemu_spice_query,
> +};
> +
> +static void spice_register_ops(void)
> +{
> +    qemu_spice_ops_register(&qemu_spice_ops);
> +}
> +type_init(spice_register_ops);
> -- 
> 2.26.2
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
Gerd Hoffmann Aug. 4, 2020, 10:18 a.m. UTC | #2
Hi,

These stubs (picked two examples) ...

> -static inline int qemu_spice_set_passwd(const char *passwd,
> -                                        bool fail_if_connected,
> -                                        bool disconnect_if_connected)
> -{
> -    return -1;
> -}

> -static inline void qemu_spice_display_init(void)
> -{
> -    /* This must never be called if CONFIG_SPICE is disabled */
> -    error_report("spice support is disabled");
> -    abort();
> -}

... can simply be moved to this place ...

> --- a/softmmu/vl.c
> +++ b/softmmu/vl.c
> @@ -173,6 +173,30 @@ int icount_align_option;
>  QemuUUID qemu_uuid;
>  bool qemu_uuid_set;
>  
> +static bool qemu_is_not_using_spice(void)
> +{
> +    return 0;
> +}
> +
> +static void qemu_spice_init_no_op(void)
> +{
> +}

(I'd suggest to name this qemu_spice_display_init_stub)

> +
> +/*
> + * Only two fields are initialized, that can be used even when SPICE
> + * is not configured or not loaded. Other functions are protected by
> + * checking if using_spice.
> + */
> +QemuSpiceOps qemu_spice = {
> +    .in_use             = qemu_is_not_using_spice,
> +    .init               = qemu_spice_init_no_op,

... and hooked up here, i.e.

       .init               = qemu_spice_display_init_stub,
       .set_passwd         = qemu_spice_set_passwd_stub,
       [ ... ]

Also I'd suggest to place the code in a new file (maybe named
ui/spice-ops.c, or ui/spice-stubs.c) which is compiled into qemu
unconditionally.

take care,
  Gerd
Gerd Hoffmann Aug. 4, 2020, 10:25 a.m. UTC | #3
> >  #ifdef CONFIG_SPICE
> > +SpiceInfo *qmp_query_spice(Error **errp)
> > +{
> > +    if (!using_spice) {
> > +        return NULL;
> > +    }
> > +    return qemu_spice.query(errp);
> > +}
> > +
> 
> It's a bit weird to put the qmp function in the hmp file.

Yes, it should go to qmp-cmds.c instead.

The #ifdef CONFIG_SPICE should not be needed.  Also the !using_spice
case should throw an error.  Or, even better, just have a
qemu_spice_query_stub() function throwing an error, then the
!using_spice check can be dropped.

take care,
  Gerd
diff mbox series

Patch

diff --git a/include/ui/qemu-spice.h b/include/ui/qemu-spice.h
index d34cea2e0f..9721d8817e 100644
--- a/include/ui/qemu-spice.h
+++ b/include/ui/qemu-spice.h
@@ -25,21 +25,28 @@ 
 #include <spice.h>
 #include "qemu/config-file.h"
 
-extern int using_spice;
+#define using_spice     (qemu_spice.in_use())
 
-void qemu_spice_init(void);
 void qemu_spice_input_init(void);
 void qemu_spice_audio_init(void);
-void qemu_spice_display_init(void);
-int qemu_spice_display_add_client(int csock, int skipauth, int tls);
 int qemu_spice_add_interface(SpiceBaseInstance *sin);
 bool qemu_spice_have_display_interface(QemuConsole *con);
 int qemu_spice_add_display_interface(QXLInstance *qxlin, QemuConsole *con);
+
+#if !defined(CONFIG_MODULES) || defined(BUILD_DSO)
+bool qemu_is_using_spice(void);
+void qemu_start_using_spice(void);
+void qemu_spice_init(void);
+void qemu_spice_display_init(void);
+int qemu_spice_display_add_client(int csock, int skipauth, int tls);
 int qemu_spice_set_passwd(const char *passwd,
                           bool fail_if_connected, bool disconnect_if_connected);
 int qemu_spice_set_pw_expire(time_t expires);
 int qemu_spice_migrate_info(const char *hostname, int port, int tls_port,
                             const char *subject);
+struct SpiceInfo *qemu_spice_query(Error **errp);
+#endif /* !CONFIG_MODULES || BUILD_DSO */
+
 
 #if !defined(SPICE_SERVER_VERSION) || (SPICE_SERVER_VERSION < 0xc06)
 #define SPICE_NEEDS_SET_MM_TIME 1
@@ -47,46 +54,33 @@  int qemu_spice_migrate_info(const char *hostname, int port, int tls_port,
 #define SPICE_NEEDS_SET_MM_TIME 0
 #endif
 
-#else  /* CONFIG_SPICE */
-
-#include "qemu/error-report.h"
-
-#define using_spice 0
-#define spice_displays 0
-static inline int qemu_spice_set_passwd(const char *passwd,
-                                        bool fail_if_connected,
-                                        bool disconnect_if_connected)
-{
-    return -1;
-}
-static inline int qemu_spice_set_pw_expire(time_t expires)
-{
-    return -1;
-}
-static inline int qemu_spice_migrate_info(const char *h, int p, int t,
-                                          const char *s)
-{
-    return -1;
-}
+#else /* !CONFIG_SPICE */
 
-static inline int qemu_spice_display_add_client(int csock, int skipauth,
-                                                int tls)
-{
-    return -1;
-}
+#define using_spice     0
 
-static inline void qemu_spice_display_init(void)
-{
-    /* This must never be called if CONFIG_SPICE is disabled */
-    error_report("spice support is disabled");
-    abort();
-}
+#endif /* CONFIG_SPICE */
 
-static inline void qemu_spice_init(void)
+/* Module high-level inteface for SPICE */
+struct QemuSpiceOps
 {
-}
-
-#endif /* CONFIG_SPICE */
+    bool (*in_use)(void);
+    void (*init)(void);
+    void (*display_init)(void);
+    int (*display_add_client)(int csock, int skipauth, int tls);
+
+    int (*set_passwd)(const char *passwd,
+                      bool fail_if_connected,
+                      bool disconnect_if_connected);
+    int (*set_pw_expire)(time_t expires);
+    int (*migrate_info)(const char *hostname,
+                        int port, int tls_port,
+                        const char *subject);
+    struct SpiceInfo * (*query)(Error **errp);
+};
+typedef struct QemuSpiceOps QemuSpiceOps;
+void qemu_spice_ops_register(QemuSpiceOps *ops);
+
+extern struct QemuSpiceOps qemu_spice;
 
 static inline bool qemu_using_spice(Error **errp)
 {
diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
index ae4b6a4246..8e10af188f 100644
--- a/monitor/hmp-cmds.c
+++ b/monitor/hmp-cmds.c
@@ -57,6 +57,7 @@ 
 
 #ifdef CONFIG_SPICE
 #include <spice/enums.h>
+#include "ui/qemu-spice.h"
 #endif
 
 void hmp_handle_error(Monitor *mon, Error *err)
@@ -573,6 +574,14 @@  void hmp_info_vnc(Monitor *mon, const QDict *qdict)
 #endif
 
 #ifdef CONFIG_SPICE
+SpiceInfo *qmp_query_spice(Error **errp)
+{
+    if (!using_spice) {
+        return NULL;
+    }
+    return qemu_spice.query(errp);
+}
+
 void hmp_info_spice(Monitor *mon, const QDict *qdict)
 {
     SpiceChannelList *chan;
@@ -599,6 +608,10 @@  void hmp_info_spice(Monitor *mon, const QDict *qdict)
 
     info = qmp_query_spice(NULL);
 
+    if (!info) {
+        monitor_printf(mon, "Server: not started\n");
+        goto out;
+    }
     if (!info->enabled) {
         monitor_printf(mon, "Server: disabled\n");
         goto out;
diff --git a/monitor/misc.c b/monitor/misc.c
index e847b58a8c..88f8915734 100644
--- a/monitor/misc.c
+++ b/monitor/misc.c
@@ -443,7 +443,7 @@  void qmp_client_migrate_info(const char *protocol, const char *hostname,
             return;
         }
 
-        if (qemu_spice_migrate_info(hostname,
+        if (qemu_spice.migrate_info(hostname,
                                     has_port ? port : -1,
                                     has_tls_port ? tls_port : -1,
                                     cert_subject)) {
diff --git a/monitor/qmp-cmds.c b/monitor/qmp-cmds.c
index 864cbfa32e..9f9822b3f3 100644
--- a/monitor/qmp-cmds.c
+++ b/monitor/qmp-cmds.c
@@ -196,7 +196,7 @@  void qmp_set_password(const char *protocol, const char *password,
         if (!qemu_using_spice(errp)) {
             return;
         }
-        rc = qemu_spice_set_passwd(password, fail_if_connected,
+        rc = qemu_spice.set_passwd(password, fail_if_connected,
                                    disconnect_if_connected);
         if (rc != 0) {
             error_setg(errp, QERR_SET_PASSWD_FAILED);
@@ -242,7 +242,7 @@  void qmp_expire_password(const char *protocol, const char *whenstr,
         if (!qemu_using_spice(errp)) {
             return;
         }
-        rc = qemu_spice_set_pw_expire(when);
+        rc = qemu_spice.set_pw_expire(when);
         if (rc != 0) {
             error_setg(errp, QERR_SET_PASSWD_FAILED);
         }
@@ -339,7 +339,7 @@  void qmp_add_client(const char *protocol, const char *fdname,
         }
         skipauth = has_skipauth ? skipauth : false;
         tls = has_tls ? tls : false;
-        if (qemu_spice_display_add_client(fd, skipauth, tls) < 0) {
+        if (qemu_spice.display_add_client(fd, skipauth, tls) < 0) {
             error_setg(errp, "spice failed to add client");
             close(fd);
         }
diff --git a/softmmu/vl.c b/softmmu/vl.c
index bc0dcc4f58..8defda56c9 100644
--- a/softmmu/vl.c
+++ b/softmmu/vl.c
@@ -173,6 +173,30 @@  int icount_align_option;
 QemuUUID qemu_uuid;
 bool qemu_uuid_set;
 
+static bool qemu_is_not_using_spice(void)
+{
+    return 0;
+}
+
+static void qemu_spice_init_no_op(void)
+{
+}
+
+/*
+ * Only two fields are initialized, that can be used even when SPICE
+ * is not configured or not loaded. Other functions are protected by
+ * checking if using_spice.
+ */
+QemuSpiceOps qemu_spice = {
+    .in_use             = qemu_is_not_using_spice,
+    .init               = qemu_spice_init_no_op,
+};
+
+void qemu_spice_ops_register(QemuSpiceOps *ops)
+{
+    memcpy(&qemu_spice, ops, sizeof(qemu_spice));
+}
+
 static NotifierList exit_notifiers =
     NOTIFIER_LIST_INITIALIZER(exit_notifiers);
 
@@ -4128,7 +4152,7 @@  void qemu_init(int argc, char **argv, char **envp)
     /* spice needs the timers to be initialized by this point */
     /* spice must initialize before audio as it changes the default auiodev */
     /* spice must initialize before chardevs (for spicevmc and spiceport) */
-    qemu_spice_init();
+    qemu_spice.init();
 
     qemu_opts_foreach(qemu_find_opts("object"),
                       user_creatable_add_opts_foreach,
@@ -4424,7 +4448,7 @@  void qemu_init(int argc, char **argv, char **envp)
 #endif
 
     if (using_spice) {
-        qemu_spice_display_init();
+        qemu_spice.display_init();
     }
 
     if (foreach_device_config(DEV_GDB, gdbserver_start) < 0) {
diff --git a/ui/spice-core.c b/ui/spice-core.c
index 37dd68f2ab..9d7ac70d92 100644
--- a/ui/spice-core.c
+++ b/ui/spice-core.c
@@ -48,7 +48,7 @@  static time_t auth_expires = TIME_MAX;
 static int spice_migration_completed;
 static int spice_display_is_running;
 static int spice_have_target_host;
-int using_spice = 0;
+static int is_using_spice;
 
 static QemuThread me;
 
@@ -503,7 +503,7 @@  static QemuOptsList qemu_spice_opts = {
     },
 };
 
-SpiceInfo *qmp_query_spice(Error **errp)
+SpiceInfo *qemu_spice_query(Error **errp)
 {
     QemuOpts *opts = QTAILQ_FIRST(&qemu_spice_opts.head);
     int port, tls_port;
@@ -634,6 +634,16 @@  static void vm_change_state_handler(void *opaque, int running,
     }
 }
 
+bool qemu_is_using_spice(void)
+{
+    return is_using_spice;
+}
+
+void qemu_start_using_spice(void)
+{
+    is_using_spice = 1;
+}
+
 void qemu_spice_init(void)
 {
     QemuOpts *opts = QTAILQ_FIRST(&qemu_spice_opts.head);
@@ -796,7 +806,7 @@  void qemu_spice_init(void)
         error_report("failed to initialize spice server");
         exit(1);
     };
-    using_spice = 1;
+    qemu_start_using_spice();
 
     migration_state.notify = migration_state_notifier;
     add_migration_state_change_notifier(&migration_state);
@@ -1000,3 +1010,20 @@  static void spice_register_config(void)
     qemu_add_opts(&qemu_spice_opts);
 }
 opts_init(spice_register_config);
+
+static QemuSpiceOps qemu_spice_ops = {
+    .in_use             = qemu_is_using_spice,
+    .init               = qemu_spice_init,
+    .display_init       = qemu_spice_display_init,
+    .display_add_client = qemu_spice_display_add_client,
+    .set_passwd         = qemu_spice_set_passwd,
+    .set_pw_expire      = qemu_spice_set_pw_expire,
+    .migrate_info       = qemu_spice_migrate_info,
+    .query              = qemu_spice_query,
+};
+
+static void spice_register_ops(void)
+{
+    qemu_spice_ops_register(&qemu_spice_ops);
+}
+type_init(spice_register_ops);