accel/hax: Introduce CONFIG_HAX_IS_POSSIBLE

Mirror "sysemu/kvm.h" #ifdef'ry to define CONFIG_HAX_IS_POSSIBLE,
expose hax_allowed to hax_enabled() macro.

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220207075426.81934-9-f4bug@amsat.org>

accel/stubs/hax-stub.c

@@ -16,6 +16,8 @@
 #include "qemu/osdep.h"
 #include "sysemu/hax.h"
 
+bool hax_allowed;
+
 int hax_sync_vcpus(void)
 {
     return 0;

include/sysemu/hax.h

@@ -25,17 +25,23 @@
 int hax_sync_vcpus(void);
 
 #ifdef NEED_CPU_H
+# ifdef CONFIG_HAX
+#  define CONFIG_HAX_IS_POSSIBLE
+# endif
+#else /* !NEED_CPU_H */
+# define CONFIG_HAX_IS_POSSIBLE
+#endif
 
-#ifdef CONFIG_HAX
+#ifdef CONFIG_HAX_IS_POSSIBLE
 
-int hax_enabled(void);
+extern bool hax_allowed;
 
-#else /* CONFIG_HAX */
+#define hax_enabled()               (hax_allowed)
 
-#define hax_enabled() (0)
+#else /* !CONFIG_HAX_IS_POSSIBLE */
 
-#endif /* CONFIG_HAX */
+#define hax_enabled()               (0)
 
-#endif /* NEED_CPU_H */
+#endif /* CONFIG_HAX_IS_POSSIBLE */
 
 #endif /* QEMU_HAX_H */

target/i386/hax/hax-all.c

@@ -49,18 +49,13 @@ const uint32_t hax_cur_version = 0x4; /* API v4: unmapping and MMIO moves */
 /* Minimum HAX kernel version */
 const uint32_t hax_min_version = 0x4; /* API v4: supports unmapping */
 
-static bool hax_allowed;
+bool hax_allowed;
 
 struct hax_state hax_global;
 
 static void hax_vcpu_sync_state(CPUArchState *env, int modified);
 static int hax_arch_get_registers(CPUArchState *env);
 
-int hax_enabled(void)
-{
-    return hax_allowed;
-}
-
 int valid_hax_tunnel_size(uint16_t size)
 {
     return size >= sizeof(struct hax_tunnel);