cpu: make CPU_INTERRUPT_RESET available on all targets

On the x86, some devices need access to the CPU reset pin (INIT#).
Provide a generic service to do this, using one of the internal
cpu_interrupt targets.  Generalize the PPC-specific code for
CPU_INTERRUPT_RESET to other targets.

Since PPC does not support migration across QEMU versions (its
machine types are not versioned yet), I picked the value that
is used on x86, CPU_INTERRUPT_TGT_INT_1.  Consequently, TGT_INT_2
and TGT_INT_3 are shifted down by one while keeping their value.

Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

cpu-exec.c

@@ -335,20 +335,26 @@ int cpu_exec(CPUArchState *env)
                         cpu_loop_exit(cpu);
                     }
 #endif
+#if defined(TARGET_I386)
+                    if (interrupt_request & CPU_INTERRUPT_INIT) {
+                        cpu_svm_check_intercept_param(env, SVM_EXIT_INIT, 0);
+                        do_cpu_init(x86_cpu);
+                        cpu->exception_index = EXCP_HALTED;
+                        cpu_loop_exit(cpu);
+                    }
+#else
+                    if (interrupt_request & CPU_INTERRUPT_RESET) {
+                        cpu_reset(cpu);
+                    }
+#endif
 #if defined(TARGET_I386)
 #if !defined(CONFIG_USER_ONLY)
                     if (interrupt_request & CPU_INTERRUPT_POLL) {
                         cpu->interrupt_request &= ~CPU_INTERRUPT_POLL;
                         apic_poll_irq(x86_cpu->apic_state);
                     }
 #endif
-                    if (interrupt_request & CPU_INTERRUPT_INIT) {
-                            cpu_svm_check_intercept_param(env, SVM_EXIT_INIT,
-                                                          0);
-                            do_cpu_init(x86_cpu);
-                            cpu->exception_index = EXCP_HALTED;
-                            cpu_loop_exit(cpu);
-                    } else if (interrupt_request & CPU_INTERRUPT_SIPI) {
+                    if (interrupt_request & CPU_INTERRUPT_SIPI) {
                             do_cpu_sipi(x86_cpu);
                     } else if (env->hflags2 & HF2_GIF_MASK) {
                         if ((interrupt_request & CPU_INTERRUPT_SMI) &&
@@ -405,9 +411,6 @@ int cpu_exec(CPUArchState *env)
                         }
                     }
 #elif defined(TARGET_PPC)
-                    if ((interrupt_request & CPU_INTERRUPT_RESET)) {
-                        cpu_reset(cpu);
-                    }
                     if (interrupt_request & CPU_INTERRUPT_HARD) {
                         ppc_hw_interrupt(env);
                         if (env->pending_interrupts == 0) {

include/exec/cpu-all.h

@@ -381,6 +381,9 @@ CPUArchState *cpu_copy(CPUArchState *env);
 /* Debug event pending.  */
 #define CPU_INTERRUPT_DEBUG       0x0080
 
+/* Reset signal.  */
+#define CPU_INTERRUPT_RESET       0x0400
+
 /* Several target-specific external hardware interrupts.  Each target/cpu.h
    should define proper names based on these defines.  */
 #define CPU_INTERRUPT_TGT_EXT_0   0x0008
@@ -395,9 +398,8 @@ CPUArchState *cpu_copy(CPUArchState *env);
    instruction being executed.  These, therefore, are not masked while
    single-stepping within the debugger.  */
 #define CPU_INTERRUPT_TGT_INT_0   0x0100
-#define CPU_INTERRUPT_TGT_INT_1   0x0400
-#define CPU_INTERRUPT_TGT_INT_2   0x0800
-#define CPU_INTERRUPT_TGT_INT_3   0x2000
+#define CPU_INTERRUPT_TGT_INT_1   0x0800
+#define CPU_INTERRUPT_TGT_INT_2   0x2000
 
 /* First unused bit: 0x4000.  */
 

target-i386/cpu.h

@@ -606,10 +606,11 @@ typedef uint32_t FeatureWordArray[FEATURE_WORDS];
 #define CPU_INTERRUPT_NMI       CPU_INTERRUPT_TGT_EXT_3
 #define CPU_INTERRUPT_MCE       CPU_INTERRUPT_TGT_EXT_4
 #define CPU_INTERRUPT_VIRQ      CPU_INTERRUPT_TGT_INT_0
-#define CPU_INTERRUPT_INIT      CPU_INTERRUPT_TGT_INT_1
-#define CPU_INTERRUPT_SIPI      CPU_INTERRUPT_TGT_INT_2
-#define CPU_INTERRUPT_TPR       CPU_INTERRUPT_TGT_INT_3
+#define CPU_INTERRUPT_SIPI      CPU_INTERRUPT_TGT_INT_1
+#define CPU_INTERRUPT_TPR       CPU_INTERRUPT_TGT_INT_2
 
+/* Use a clearer name for this.  */
+#define CPU_INTERRUPT_INIT      CPU_INTERRUPT_RESET
 
 typedef enum {
     CC_OP_DYNAMIC, /* must use dynamic code to get cc_op */

target-ppc/cpu.h

@@ -2042,9 +2042,6 @@ enum {
     PPC_INTERRUPT_PERFM,          /* Performance monitor interrupt        */
 };
 
-/* CPU should be reset next, restart from scratch afterwards */
-#define CPU_INTERRUPT_RESET       CPU_INTERRUPT_TGT_INT_0
-
 /*****************************************************************************/
 
 static inline target_ulong cpu_read_xer(CPUPPCState *env)