gdb: provide the name of the architecture in the target.xml

This patch provides the name of the architecture in the target.xml
if available.

This allows the remote gdb to detect the target architecture on its
own - so there is no need to specify it manually (e.g. if gdb is
started without a binary) using "set arch *arch_name*".

The name of the architecture is provided by a callback that can
be implemented by all architectures. The arm implementation has
special handling for iwmmxt and returns arm otherwise. This can
be extended if necessary.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
[rework to use a callback]
Message-Id: <1449144881-130935-1-git-send-email-borntraeger@de.ibm.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>

gdbstub.c

@@ -540,13 +540,20 @@ static const char *get_feature_xml(const char *p, const char **newp,
             GDBRegisterState *r;
             CPUState *cpu = first_cpu;
 
-            snprintf(target_xml, sizeof(target_xml),
-                     "<?xml version=\"1.0\"?>"
-                     "<!DOCTYPE target SYSTEM \"gdb-target.dtd\">"
-                     "<target>"
-                     "<xi:include href=\"%s\"/>",
-                     cc->gdb_core_xml_file);
-
+            pstrcat(target_xml, sizeof(target_xml),
+                    "<?xml version=\"1.0\"?>"
+                    "<!DOCTYPE target SYSTEM \"gdb-target.dtd\">"
+                    "<target>");
+            if (cc->gdb_arch_name) {
+                gchar *arch = cc->gdb_arch_name(cpu);
+                pstrcat(target_xml, sizeof(target_xml), "<architecture>");
+                pstrcat(target_xml, sizeof(target_xml), arch);
+                pstrcat(target_xml, sizeof(target_xml), "</architecture>");
+                g_free(arch);
+            }
+            pstrcat(target_xml, sizeof(target_xml), "<xi:include href=\"");
+            pstrcat(target_xml, sizeof(target_xml), cc->gdb_core_xml_file);
+            pstrcat(target_xml, sizeof(target_xml), "\"/>");
             for (r = cpu->gdb_regs; r; r = r->next) {
                 pstrcat(target_xml, sizeof(target_xml), "<xi:include href=\"");
                 pstrcat(target_xml, sizeof(target_xml), r->xml);

include/qom/cpu.h

@@ -120,6 +120,8 @@ struct TranslationBlock;
  * @gdb_core_xml_file: File name for core registers GDB XML description.
  * @gdb_stop_before_watchpoint: Indicates whether GDB expects the CPU to stop
  *           before the insn which triggers a watchpoint rather than after it.
+ * @gdb_arch_name: Optional callback that returns the architecture name known
+ * to GDB. The caller must free the returned string with g_free.
  * @cpu_exec_enter: Callback for cpu_exec preparation.
  * @cpu_exec_exit: Callback for cpu_exec cleanup.
  * @cpu_exec_interrupt: Callback for processing interrupts in cpu_exec.
@@ -177,6 +179,7 @@ typedef struct CPUClass {
     const struct VMStateDescription *vmsd;
     int gdb_num_core_regs;
     const char *gdb_core_xml_file;
+    gchar * (*gdb_arch_name)(CPUState *cpu);
     bool gdb_stop_before_watchpoint;
 
     void (*cpu_exec_enter)(CPUState *cpu);

target-arm/cpu.c

@@ -1426,6 +1426,17 @@ static int arm_cpu_handle_mmu_fault(CPUState *cs, vaddr address, int rw,
 }
 #endif
 
+static gchar *arm_gdb_arch_name(CPUState *cs)
+{
+    ARMCPU *cpu = ARM_CPU(cs);
+    CPUARMState *env = &cpu->env;
+
+    if (arm_feature(env, ARM_FEATURE_IWMMXT)) {
+        return g_strdup("iwmmxt");
+    }
+    return g_strdup("arm");
+}
+
 static void arm_cpu_class_init(ObjectClass *oc, void *data)
 {
     ARMCPUClass *acc = ARM_CPU_CLASS(oc);
@@ -1460,6 +1471,7 @@ static void arm_cpu_class_init(ObjectClass *oc, void *data)
 #endif
     cc->gdb_num_core_regs = 26;
     cc->gdb_core_xml_file = "arm-core.xml";
+    cc->gdb_arch_name = arm_gdb_arch_name;
     cc->gdb_stop_before_watchpoint = true;
     cc->debug_excp_handler = arm_debug_excp_handler;
 

target-arm/cpu64.c

@@ -287,6 +287,11 @@ static void aarch64_cpu_set_pc(CPUState *cs, vaddr value)
     }
 }
 
+static gchar *aarch64_gdb_arch_name(CPUState *cs)
+{
+    return g_strdup("aarch64");
+}
+
 static void aarch64_cpu_class_init(ObjectClass *oc, void *data)
 {
     CPUClass *cc = CPU_CLASS(oc);
@@ -297,6 +302,7 @@ static void aarch64_cpu_class_init(ObjectClass *oc, void *data)
     cc->gdb_write_register = aarch64_cpu_gdb_write_register;
     cc->gdb_num_core_regs = 34;
     cc->gdb_core_xml_file = "aarch64-core.xml";
+    cc->gdb_arch_name = aarch64_gdb_arch_name;
 }
 
 static void aarch64_cpu_register(const ARMCPUInfo *info)

target-ppc/translate_init.c

@@ -9681,6 +9681,15 @@ static bool ppc_pvr_match_default(PowerPCCPUClass *pcc, uint32_t pvr)
     return pcc->pvr == pvr;
 }
 
+static gchar *ppc_gdb_arch_name(CPUState *cs)
+{
+#if defined(TARGET_PPC64)
+    return g_strdup("powerpc:common64");
+#else
+    return g_strdup("powerpc:common");
+#endif
+}
+
 static void ppc_cpu_class_init(ObjectClass *oc, void *data)
 {
     PowerPCCPUClass *pcc = POWERPC_CPU_CLASS(oc);
@@ -9724,6 +9733,7 @@ static void ppc_cpu_class_init(ObjectClass *oc, void *data)
     cc->gdb_num_core_regs = 71 + 32;
 #endif
 
+    cc->gdb_arch_name = ppc_gdb_arch_name;
 #if defined(TARGET_PPC64)
     cc->gdb_core_xml_file = "power64-core.xml";
 #else

target-s390x/cpu.c

@@ -325,6 +325,11 @@ unsigned int s390_cpu_set_state(uint8_t cpu_state, S390CPU *cpu)
 }
 #endif
 
+static gchar *s390_gdb_arch_name(CPUState *cs)
+{
+    return g_strdup("s390:64-bit");
+}
+
 static void s390_cpu_class_init(ObjectClass *oc, void *data)
 {
     S390CPUClass *scc = S390_CPU_CLASS(oc);
@@ -360,6 +365,7 @@ static void s390_cpu_class_init(ObjectClass *oc, void *data)
 
     cc->gdb_num_core_regs = S390_NUM_CORE_REGS;
     cc->gdb_core_xml_file = "s390x-core64.xml";
+    cc->gdb_arch_name = s390_gdb_arch_name;
 
     /*
      * Reason: s390_cpu_initfn() calls cpu_exec_init(), which saves