x86: Debug register emulation (Jan Kiszka)

Built on top of previously enhanced breakpoint/watchpoint support, this
patch adds full debug register emulation for the x86 architecture.

Many corner cases were considered, and the result was successfully
tested inside a Linux guest with gdb, but I won't be surprised if one
or two scenarios still behave differently in reality.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5747 c046a42c-6fe2-441c-8c8c-71466251a162
diff --git a/linux-user/main.c b/linux-user/main.c
index f17d012..66be107 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -403,7 +403,7 @@
                 queue_signal(env, info.si_signo, &info);
             }
             break;
-        case EXCP01_SSTP:
+        case EXCP01_DB:
         case EXCP03_INT3:
 #ifndef TARGET_X86_64
             if (env->eflags & VM_MASK) {
@@ -413,7 +413,7 @@
             {
                 info.si_signo = SIGTRAP;
                 info.si_errno = 0;
-                if (trapnr == EXCP01_SSTP) {
+                if (trapnr == EXCP01_DB) {
                     info.si_code = TARGET_TRAP_BRKPT;
                     info._sifields._sigfault._addr = env->eip;
                 } else {