[Qemu-devel] [PATCH] x86: Reboot CPU on triple fault - Version 6

[Kevin Wolf <kwolf@suse.de>]

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Quite a few rounds for such a short patch. But surely a CPU dump without
any explanation isn't optimal. We should put a "CPU Reset" line in the
log before the dump.

Signed-off-by: Kevin Wolf <kwolf@suse.de>

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Index: dyngen-exec.h
===================================================================
--- dyngen-exec.h	(Revision 4215)
+++ dyngen-exec.h	(Arbeitskopie)
@@ -86,6 +86,7 @@
 extern int fprintf(FILE *, const char *, ...);
 extern int fputs(const char *, FILE *);
 extern int printf(const char *, ...);
+extern FILE *stderr;
 #undef NULL
 #define NULL 0
 
Index: exec.c
===================================================================
--- exec.c	(Revision 4215)
+++ exec.c	(Arbeitskopie)
@@ -1259,6 +1259,8 @@
 #ifdef TARGET_I386
     { CPU_LOG_PCALL, "pcall",
       "show protected mode far calls/returns/exceptions" },
+    { CPU_LOG_RESET, "cpu_reset",
+      "show CPU state before CPU resets" },
 #endif
 #ifdef DEBUG_IOPORT
     { CPU_LOG_IOPORT, "ioport",
Index: target-i386/helper.c
===================================================================
--- target-i386/helper.c	(Revision 4215)
+++ target-i386/helper.c	(Arbeitskopie)
@@ -1231,6 +1231,9 @@
     }
 }
 
+/* This should come from sysemu.h - if we could include it here... */
+void qemu_system_reset_request(void);
+
 /*
  * Check nested exceptions and change to double or triple fault if
  * needed. It should only be called, if this is not an interrupt.
@@ -1248,9 +1251,20 @@
         fprintf(logfile, "check_exception old: %x new %x\n",
                 env->old_exception, intno);
 
-    if (env->old_exception == EXCP08_DBLE)
-        cpu_abort(env, "triple fault");
+    if (env->old_exception == EXCP08_DBLE) {
+        if(env->intercept & INTERCEPT_SVM_MASK) {
+            /* most probably the virtual machine should not
+               be shut down but rather caught by the VMM */
+            vmexit(SVM_EXIT_SHUTDOWN, 0);
+        }
 
+        if (loglevel & CPU_LOG_RESET)
+            fprintf(logfile, "Triple fault\n");
+
+        qemu_system_reset_request();
+        return EXCP_HLT;
+    }
+
     if ((first_contributory && second_contributory)
         || (env->old_exception == EXCP0E_PAGE &&
             (second_contributory || (intno == EXCP0E_PAGE)))) {
Index: target-i386/helper2.c
===================================================================
--- target-i386/helper2.c	(Revision 4215)
+++ target-i386/helper2.c	(Arbeitskopie)
@@ -362,6 +362,11 @@
 void cpu_reset(CPUX86State *env)
 {
     int i;
+        
+    if (loglevel & CPU_LOG_RESET) {
+        fprintf(logfile, "CPU Reset (CPU %d)\n", env->cpu_index);
+        cpu_dump_state(env, logfile, fprintf, X86_DUMP_FPU | X86_DUMP_CCOP);
+    }
 
     memset(env, 0, offsetof(CPUX86State, breakpoints));
 
Index: cpu-all.h
===================================================================
--- cpu-all.h	(Revision 4215)
+++ cpu-all.h	(Arbeitskopie)
@@ -779,6 +779,7 @@
 #define CPU_LOG_PCALL      (1 << 6)
 #define CPU_LOG_IOPORT     (1 << 7)
 #define CPU_LOG_TB_CPU     (1 << 8)
+#define CPU_LOG_RESET      (1 << 9)
 
 /* define log items */
 typedef struct CPULogItem {