kvm: Separate TCG from KVM cpu execution

Mixing up TCG bits with KVM already led to problems around eflags
emulation on x86. Moreover, quite some code that TCG requires on cpu
enty/exit is useless for KVM. So dispatch between tcg_cpu_exec and
kvm_cpu_exec as early as possible.

The core logic of cpu_halted from cpu_exec is added to
kvm_arch_process_irqchip_events. Moving away from cpu_exec makes
exception_index meaningless for KVM, we can simply pass the exit reason
directly (only "EXCP_DEBUG vs. rest" is relevant).

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/cpu-exec.c b/cpu-exec.c
index 9c0b10d..b03b3a7 100644
--- a/cpu-exec.c
+++ b/cpu-exec.c
@@ -226,13 +226,11 @@
     }
 
 #if defined(TARGET_I386)
-    if (!kvm_enabled()) {
-        /* put eflags in CPU temporary format */
-        CC_SRC = env->eflags & (CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C);
-        DF = 1 - (2 * ((env->eflags >> 10) & 1));
-        CC_OP = CC_OP_EFLAGS;
-        env->eflags &= ~(DF_MASK | CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C);
-    }
+    /* put eflags in CPU temporary format */
+    CC_SRC = env->eflags & (CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C);
+    DF = 1 - (2 * ((env->eflags >> 10) & 1));
+    CC_OP = CC_OP_EFLAGS;
+    env->eflags &= ~(DF_MASK | CC_O | CC_S | CC_Z | CC_A | CC_P | CC_C);
 #elif defined(TARGET_SPARC)
 #elif defined(TARGET_M68K)
     env->cc_op = CC_OP_FLAGS;
@@ -257,7 +255,7 @@
         if (setjmp(env->jmp_env) == 0) {
 #if defined(__sparc__) && !defined(CONFIG_SOLARIS)
 #undef env
-                    env = cpu_single_env;
+            env = cpu_single_env;
 #define env cpu_single_env
 #endif
             /* if an exception is pending, we execute it here */
@@ -316,11 +314,6 @@
                 }
             }
 
-            if (kvm_enabled()) {
-                kvm_cpu_exec(env);
-                longjmp(env->jmp_env, 1);
-            }
-
             next_tb = 0; /* force lookup of first TB */
             for(;;) {
                 interrupt_request = env->interrupt_request;