1 files changed, 54 insertions, 44 deletions

diff --git a/accel/tcg/tcg-all.c b/accel/tcg/tcg-all.c
index c1a30b0..b0d4e3e 100644
--- a/accel/tcg/tcg-all.c
+++ b/accel/tcg/tcg-all.c
@@ -26,27 +26,30 @@
 #include "qemu/osdep.h"
 #include "system/tcg.h"
 #include "exec/replay-core.h"
-#include "system/cpu-timers.h"
+#include "exec/icount.h"
 #include "tcg/startup.h"
 #include "qapi/error.h"
 #include "qemu/error-report.h"
 #include "qemu/accel.h"
 #include "qemu/atomic.h"
+#include "qapi/qapi-types-common.h"
 #include "qapi/qapi-builtin-visit.h"
 #include "qemu/units.h"
 #if defined(CONFIG_USER_ONLY)
 #include "hw/qdev-core.h"
 #else
 #include "hw/boards.h"
+#include "system/tcg.h"
 #endif
+#include "accel/tcg/cpu-ops.h"
 #include "internal-common.h"
-#include "cpu-param.h"
+#include "cpu.h"
 
 
 struct TCGState {
     AccelState parent_obj;
 
-    bool mttcg_enabled;
+    OnOffAuto mttcg_enabled;
     bool one_insn_per_tb;
     int splitwx_enabled;
     unsigned long tb_size;
@@ -58,40 +61,18 @@ typedef struct TCGState TCGState;
 DECLARE_INSTANCE_CHECKER(TCGState, TCG_STATE,
                          TYPE_TCG_ACCEL)
 
-/*
- * We default to false if we know other options have been enabled
- * which are currently incompatible with MTTCG. Otherwise when each
- * guest (target) has been updated to support:
- *   - atomic instructions
- *   - memory ordering primitives (barriers)
- * they can set the appropriate CONFIG flags in ${target}-softmmu.mak
- *
- * Once a guest architecture has been converted to the new primitives
- * there is one remaining limitation to check:
- *   - The guest can't be oversized (e.g. 64 bit guest on 32 bit host)
- */
-
-static bool default_mttcg_enabled(void)
+#ifndef CONFIG_USER_ONLY
+bool qemu_tcg_mttcg_enabled(void)
 {
-    if (icount_enabled()) {
-        return false;
-    }
-#ifdef TARGET_SUPPORTS_MTTCG
-# ifndef TCG_GUEST_DEFAULT_MO
-#  error "TARGET_SUPPORTS_MTTCG without TCG_GUEST_DEFAULT_MO"
-# endif
-    return true;
-#else
-    return false;
-#endif
+    TCGState *s = TCG_STATE(current_accel());
+    return s->mttcg_enabled == ON_OFF_AUTO_ON;
 }
+#endif /* !CONFIG_USER_ONLY */
 
 static void tcg_accel_instance_init(Object *obj)
 {
     TCGState *s = TCG_STATE(obj);
 
-    s->mttcg_enabled = default_mttcg_enabled();
-
     /* If debugging enabled, default "auto on", otherwise off. */
 #if defined(CONFIG_DEBUG_TCG) && !defined(CONFIG_USER_ONLY)
     s->splitwx_enabled = -1;
@@ -100,24 +81,57 @@ static void tcg_accel_instance_init(Object *obj)
 #endif
 }
 
-bool mttcg_enabled;
 bool one_insn_per_tb;
 
 static int tcg_init_machine(MachineState *ms)
 {
     TCGState *s = TCG_STATE(current_accel());
-#ifdef CONFIG_USER_ONLY
-    unsigned max_cpus = 1;
-#else
-    unsigned max_cpus = ms->smp.max_cpus;
+    unsigned max_threads = 1;
+
+#ifndef CONFIG_USER_ONLY
+    CPUClass *cc = CPU_CLASS(object_class_by_name(CPU_RESOLVING_TYPE));
+    bool mttcg_supported = cc->tcg_ops->mttcg_supported;
+
+    switch (s->mttcg_enabled) {
+    case ON_OFF_AUTO_AUTO:
+        /*
+         * We default to false if we know other options have been enabled
+         * which are currently incompatible with MTTCG. Otherwise when each
+         * guest (target) has been updated to support:
+         *   - atomic instructions
+         *   - memory ordering primitives (barriers)
+         * they can set the appropriate CONFIG flags in ${target}-softmmu.mak
+         *
+         * Once a guest architecture has been converted to the new primitives
+         * there is one remaining limitation to check:
+         *   - The guest can't be oversized (e.g. 64 bit guest on 32 bit host)
+         */
+        if (mttcg_supported && !icount_enabled()) {
+            s->mttcg_enabled = ON_OFF_AUTO_ON;
+            max_threads = ms->smp.max_cpus;
+        } else {
+            s->mttcg_enabled = ON_OFF_AUTO_OFF;
+        }
+        break;
+    case ON_OFF_AUTO_ON:
+        if (!mttcg_supported) {
+            warn_report("Guest not yet converted to MTTCG - "
+                        "you may get unexpected results");
+        }
+        max_threads = ms->smp.max_cpus;
+        break;
+    case ON_OFF_AUTO_OFF:
+        break;
+    default:
+        g_assert_not_reached();
+    }
 #endif
 
     tcg_allowed = true;
-    mttcg_enabled = s->mttcg_enabled;
 
     page_init();
     tb_htable_init();
-    tcg_init(s->tb_size * MiB, s->splitwx_enabled, max_cpus);
+    tcg_init(s->tb_size * MiB, s->splitwx_enabled, max_threads);
 
 #if defined(CONFIG_SOFTMMU)
     /*
@@ -138,7 +152,7 @@ static char *tcg_get_thread(Object *obj, Error **errp)
 {
     TCGState *s = TCG_STATE(obj);
 
-    return g_strdup(s->mttcg_enabled ? "multi" : "single");
+    return g_strdup(s->mttcg_enabled == ON_OFF_AUTO_ON ? "multi" : "single");
 }
 
 static void tcg_set_thread(Object *obj, const char *value, Error **errp)
@@ -149,14 +163,10 @@ static void tcg_set_thread(Object *obj, const char *value, Error **errp)
         if (icount_enabled()) {
             error_setg(errp, "No MTTCG when icount is enabled");
         } else {
-#ifndef TARGET_SUPPORTS_MTTCG
-            warn_report("Guest not yet converted to MTTCG - "
-                        "you may get unexpected results");
-#endif
-            s->mttcg_enabled = true;
+            s->mttcg_enabled = ON_OFF_AUTO_ON;
         }
     } else if (strcmp(value, "single") == 0) {
-        s->mttcg_enabled = false;
+        s->mttcg_enabled = ON_OFF_AUTO_OFF;
     } else {
         error_setg(errp, "Invalid 'thread' setting %s", value);
     }