target/riscv: Use gdb xml according to max mxlen

Signed-off-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20220120122050.41546-9-zhiwei_liu@c-sky.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

target/riscv/cpu.c

@@ -466,6 +466,7 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
     RISCVCPU *cpu = RISCV_CPU(dev);
     CPURISCVState *env = &cpu->env;
     RISCVCPUClass *mcc = RISCV_CPU_GET_CLASS(dev);
+    CPUClass *cc = CPU_CLASS(mcc);
     int priv_version = 0;
     Error *local_err = NULL;
 
@@ -516,11 +517,13 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
     switch (env->misa_mxl_max) {
 #ifdef TARGET_RISCV64
     case MXL_RV64:
+        cc->gdb_core_xml_file = "riscv-64bit-cpu.xml";
         break;
     case MXL_RV128:
         break;
 #endif
     case MXL_RV32:
+        cc->gdb_core_xml_file = "riscv-32bit-cpu.xml";
         break;
     default:
         g_assert_not_reached();
@@ -802,11 +805,6 @@ static void riscv_cpu_class_init(ObjectClass *c, void *data)
     cc->gdb_read_register = riscv_cpu_gdb_read_register;
     cc->gdb_write_register = riscv_cpu_gdb_write_register;
     cc->gdb_num_core_regs = 33;
-#if defined(TARGET_RISCV32)
-    cc->gdb_core_xml_file = "riscv-32bit-cpu.xml";
-#elif defined(TARGET_RISCV64)
-    cc->gdb_core_xml_file = "riscv-64bit-cpu.xml";
-#endif
     cc->gdb_stop_before_watchpoint = true;
     cc->disas_set_info = riscv_cpu_disas_set_info;
 #ifndef CONFIG_USER_ONLY

target/riscv/gdbstub.c

@@ -50,11 +50,23 @@ int riscv_cpu_gdb_read_register(CPUState *cs, GByteArray *mem_buf, int n)
 {
     RISCVCPU *cpu = RISCV_CPU(cs);
     CPURISCVState *env = &cpu->env;
+    target_ulong tmp;
 
     if (n < 32) {
-        return gdb_get_regl(mem_buf, env->gpr[n]);
+        tmp = env->gpr[n];
     } else if (n == 32) {
-        return gdb_get_regl(mem_buf, env->pc);
+        tmp = env->pc;
+    } else {
+        return 0;
+    }
+
+    switch (env->misa_mxl_max) {
+    case MXL_RV32:
+        return gdb_get_reg32(mem_buf, tmp);
+    case MXL_RV64:
+        return gdb_get_reg64(mem_buf, tmp);
+    default:
+        g_assert_not_reached();
     }
     return 0;
 }
@@ -63,18 +75,32 @@ int riscv_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
 {
     RISCVCPU *cpu = RISCV_CPU(cs);
     CPURISCVState *env = &cpu->env;
+    int length = 0;
+    target_ulong tmp;
 
-    if (n == 0) {
+    switch (env->misa_mxl_max) {
-        /* discard writes to x0 */
+    case MXL_RV32:
-        return sizeof(target_ulong);
+        tmp = (int32_t)ldl_p(mem_buf);
-    } else if (n < 32) {
+        length = 4;
-        env->gpr[n] = ldtul_p(mem_buf);
+        break;
-        return sizeof(target_ulong);
+    case MXL_RV64:
-    } else if (n == 32) {
+        if (env->xl < MXL_RV64) {
-        env->pc = ldtul_p(mem_buf);
+            tmp = (int32_t)ldq_p(mem_buf);
-        return sizeof(target_ulong);
+        } else {
+            tmp = ldq_p(mem_buf);
+        }
+        length = 8;
+        break;
+    default:
+        g_assert_not_reached();
     }
-    return 0;
+    if (n > 0 && n < 32) {
+        env->gpr[n] = tmp;
+    } else if (n == 32) {
+        env->pc = tmp;
+    }
+
+    return length;
 }
 
 static int riscv_gdb_get_fpu(CPURISCVState *env, GByteArray *buf, int n)
@@ -387,13 +413,20 @@ void riscv_cpu_register_gdb_regs_for_features(CPUState *cs)
                                                               cs->gdb_num_regs),
                                  "riscv-vector.xml", 0);
     }
-#if defined(TARGET_RISCV32)
+    switch (env->misa_mxl_max) {
-    gdb_register_coprocessor(cs, riscv_gdb_get_virtual, riscv_gdb_set_virtual,
+    case MXL_RV32:
-                             1, "riscv-32bit-virtual.xml", 0);
+        gdb_register_coprocessor(cs, riscv_gdb_get_virtual,
-#elif defined(TARGET_RISCV64)
+                                 riscv_gdb_set_virtual,
-    gdb_register_coprocessor(cs, riscv_gdb_get_virtual, riscv_gdb_set_virtual,
+                                 1, "riscv-32bit-virtual.xml", 0);
-                             1, "riscv-64bit-virtual.xml", 0);
+        break;
-#endif
+    case MXL_RV64:
+        gdb_register_coprocessor(cs, riscv_gdb_get_virtual,
+                                 riscv_gdb_set_virtual,
+                                 1, "riscv-64bit-virtual.xml", 0);
+        break;
+    default:
+        g_assert_not_reached();
+    }
 
     gdb_register_coprocessor(cs, riscv_gdb_get_csr, riscv_gdb_set_csr,
                              riscv_gen_dynamic_csr_xml(cs, cs->gdb_num_regs),