cpu: Introduce CPUState::gdb_num_regs and CPUClass::gdb_num_core_regs

CPUState::gdb_num_regs replaces num_g_regs.
CPUClass::gdb_num_core_regs replaces NUM_CORE_REGS.

Allows building gdb_register_coprocessor() for xtensa, too.

As a side effect this should fix coprocessor register numbering for SMP.

Acked-by: Michael Walle <michael@walle.cc> (for lm32)
Acked-by: Max Filippov <jcmvbkbc@gmail.com> (for xtensa)
Signed-off-by: Andreas Färber <afaerber@suse.de>

18 files changed, 66 insertions, 65 deletions

diff --git a/gdbstub.c b/gdbstub.c
index 9ede3de7ae..4879055c60 100644
--- a/gdbstub.c
+++ b/gdbstub.c
@@ -530,8 +530,6 @@ static const int gpr_map[16] = {
 #endif
 static const int gpr_map32[8] = { 0, 1, 2, 3, 4, 5, 6, 7 };
 
-#define NUM_CORE_REGS (CPU_NB_REGS * 2 + 25)
-
 #define IDX_IP_REG      CPU_NB_REGS
 #define IDX_FLAGS_REG   (IDX_IP_REG + 1)
 #define IDX_SEG_REGS    (IDX_FLAGS_REG + 1)
@@ -732,7 +730,6 @@ static int cpu_gdb_write_register(CPUX86State *env, uint8_t *mem_buf, int n)
    historical mishap the FP registers appear in between core integer
    regs and PC, MSR, CR, and so forth.  We hack round this by giving the
    FP regs zero size when talking to a newer gdb.  */
-#define NUM_CORE_REGS 71
 #if defined (TARGET_PPC64)
 #define GDB_CORE_XML "power64-core.xml"
 #else
@@ -837,12 +834,6 @@ static int cpu_gdb_write_register(CPUPPCState *env, uint8_t *mem_buf, int n)
 
 #elif defined (TARGET_SPARC)
 
-#if defined(TARGET_SPARC64) && !defined(TARGET_ABI32)
-#define NUM_CORE_REGS 86
-#else
-#define NUM_CORE_REGS 72
-#endif
-
 #ifdef TARGET_ABI32
 #define GET_REGA(val) GET_REG32(val)
 #else
@@ -1030,7 +1021,6 @@ static int cpu_gdb_write_register(CPUSPARCState *env, uint8_t *mem_buf, int n)
    the FPA registers appear in between core integer regs and the CPSR.
    We hack round this by giving the FPA regs zero size when talking to a
    newer gdb.  */
-#define NUM_CORE_REGS 26
 #define GDB_CORE_XML "arm-core.xml"
 
 static int cpu_gdb_read_register(CPUARMState *env, uint8_t *mem_buf, int n)
@@ -1104,8 +1094,6 @@ static int cpu_gdb_write_register(CPUARMState *env, uint8_t *mem_buf, int n)
 
 #elif defined (TARGET_M68K)
 
-#define NUM_CORE_REGS 18
-
 #define GDB_CORE_XML "cf-core.xml"
 
 static int cpu_gdb_read_register(CPUM68KState *env, uint8_t *mem_buf, int n)
@@ -1157,8 +1145,6 @@ static int cpu_gdb_write_register(CPUM68KState *env, uint8_t *mem_buf, int n)
 }
 #elif defined (TARGET_MIPS)
 
-#define NUM_CORE_REGS 73
-
 static int cpu_gdb_read_register(CPUMIPSState *env, uint8_t *mem_buf, int n)
 {
     if (n < 32) {
@@ -1285,8 +1271,6 @@ static int cpu_gdb_write_register(CPUMIPSState *env, uint8_t *mem_buf, int n)
 }
 #elif defined(TARGET_OPENRISC)
 
-#define NUM_CORE_REGS (32 + 3)
-
 static int cpu_gdb_read_register(CPUOpenRISCState *env, uint8_t *mem_buf, int n)
 {
     if (n < 32) {
@@ -1312,9 +1296,11 @@ static int cpu_gdb_read_register(CPUOpenRISCState *env, uint8_t *mem_buf, int n)
 static int cpu_gdb_write_register(CPUOpenRISCState *env,
                                   uint8_t *mem_buf, int n)
 {
+    OpenRISCCPU *cpu = openrisc_env_get_cpu(env);
+    CPUClass *cc = CPU_GET_CLASS(cpu);
     uint32_t tmp;
 
-    if (n > NUM_CORE_REGS) {
+    if (n > cc->gdb_num_core_regs) {
         return 0;
     }
 
@@ -1347,8 +1333,6 @@ static int cpu_gdb_write_register(CPUOpenRISCState *env,
 /* Hint: Use "set architecture sh4" in GDB to see fpu registers */
 /* FIXME: We should use XML for this.  */
 
-#define NUM_CORE_REGS 59
-
 static int cpu_gdb_read_register(CPUSH4State *env, uint8_t *mem_buf, int n)
 {
     switch (n) {
@@ -1465,8 +1449,6 @@ static int cpu_gdb_write_register(CPUSH4State *env, uint8_t *mem_buf, int n)
 }
 #elif defined (TARGET_MICROBLAZE)
 
-#define NUM_CORE_REGS (32 + 5)
-
 static int cpu_gdb_read_register(CPUMBState *env, uint8_t *mem_buf, int n)
 {
     if (n < 32) {
@@ -1479,9 +1461,11 @@ static int cpu_gdb_read_register(CPUMBState *env, uint8_t *mem_buf, int n)
 
 static int cpu_gdb_write_register(CPUMBState *env, uint8_t *mem_buf, int n)
 {
+    MicroBlazeCPU *cpu = mb_env_get_cpu(env);
+    CPUClass *cc = CPU_GET_CLASS(cpu);
     uint32_t tmp;
 
-    if (n > NUM_CORE_REGS) {
+    if (n > cc->gdb_num_core_regs) {
         return 0;
     }
 
@@ -1496,8 +1480,6 @@ static int cpu_gdb_write_register(CPUMBState *env, uint8_t *mem_buf, int n)
 }
 #elif defined (TARGET_CRIS)
 
-#define NUM_CORE_REGS 49
-
 static int
 read_register_crisv10(CPUCRISState *env, uint8_t *mem_buf, int n)
 {
@@ -1605,8 +1587,6 @@ static int cpu_gdb_write_register(CPUCRISState *env, uint8_t *mem_buf, int n)
 }
 #elif defined (TARGET_ALPHA)
 
-#define NUM_CORE_REGS 67
-
 static int cpu_gdb_read_register(CPUAlphaState *env, uint8_t *mem_buf, int n)
 {
     uint64_t val;
@@ -1675,8 +1655,6 @@ static int cpu_gdb_write_register(CPUAlphaState *env, uint8_t *mem_buf, int n)
 }
 #elif defined (TARGET_S390X)
 
-#define NUM_CORE_REGS  S390_NUM_REGS
-
 static int cpu_gdb_read_register(CPUS390XState *env, uint8_t *mem_buf, int n)
 {
     uint64_t val;
@@ -1740,7 +1718,6 @@ static int cpu_gdb_write_register(CPUS390XState *env, uint8_t *mem_buf, int n)
 #elif defined (TARGET_LM32)
 
 #include "hw/lm32/lm32_pic.h"
-#define NUM_CORE_REGS (32 + 7)
 
 static int cpu_gdb_read_register(CPULM32State *env, uint8_t *mem_buf, int n)
 {
@@ -1770,9 +1747,11 @@ static int cpu_gdb_read_register(CPULM32State *env, uint8_t *mem_buf, int n)
 
 static int cpu_gdb_write_register(CPULM32State *env, uint8_t *mem_buf, int n)
 {
+    LM32CPU *cpu = lm32_env_get_cpu(env);
+    CPUClass *cc = CPU_GET_CLASS(cpu);
     uint32_t tmp;
 
-    if (n > NUM_CORE_REGS) {
+    if (n > cc->gdb_num_core_regs) {
         return 0;
     }
 
@@ -1806,14 +1785,6 @@ static int cpu_gdb_write_register(CPULM32State *env, uint8_t *mem_buf, int n)
 }
 #elif defined(TARGET_XTENSA)
 
-/* Use num_core_regs to see only non-privileged registers in an unmodified gdb.
- * Use num_regs to see all registers. gdb modification is required for that:
- * reset bit 0 in the 'flags' field of the registers definitions in the
- * gdb/xtensa-config.c inside gdb source tree or inside gdb overlay.
- */
-#define NUM_CORE_REGS (env->config->gdb_regmap.num_regs)
-#define num_g_regs NUM_CORE_REGS
-
 static int cpu_gdb_read_register(CPUXtensaState *env, uint8_t *mem_buf, int n)
 {
     const XtensaGdbReg *reg = env->config->gdb_regmap.reg + n;
@@ -1896,8 +1867,6 @@ static int cpu_gdb_write_register(CPUXtensaState *env, uint8_t *mem_buf, int n)
 }
 #else
 
-#define NUM_CORE_REGS 0
-
 static int cpu_gdb_read_register(CPUArchState *env, uint8_t *mem_buf, int n)
 {
     return 0;
@@ -1910,10 +1879,6 @@ static int cpu_gdb_write_register(CPUArchState *env, uint8_t *mem_buf, int n)
 
 #endif
 
-#if !defined(TARGET_XTENSA)
-static int num_g_regs = NUM_CORE_REGS;
-#endif
-
 #ifdef GDB_CORE_XML
 /* Encode data using the encoding for 'x' packets.  */
 static int memtox(char *buf, const char *mem, int len)
@@ -1982,11 +1947,13 @@ static const char *get_feature_xml(const char *p, const char **newp)
 
 static int gdb_read_register(CPUState *cpu, uint8_t *mem_buf, int reg)
 {
+    CPUClass *cc = CPU_GET_CLASS(cpu);
     CPUArchState *env = cpu->env_ptr;
     GDBRegisterState *r;
 
-    if (reg < NUM_CORE_REGS)
+    if (reg < cc->gdb_num_core_regs) {
         return cpu_gdb_read_register(env, mem_buf, reg);
+    }
 
     for (r = cpu->gdb_regs; r; r = r->next) {
         if (r->base_reg <= reg && reg < r->base_reg + r->num_regs) {
@@ -1998,11 +1965,13 @@ static int gdb_read_register(CPUState *cpu, uint8_t *mem_buf, int reg)
 
 static int gdb_write_register(CPUState *cpu, uint8_t *mem_buf, int reg)
 {
+    CPUClass *cc = CPU_GET_CLASS(cpu);
     CPUArchState *env = cpu->env_ptr;
     GDBRegisterState *r;
 
-    if (reg < NUM_CORE_REGS)
+    if (reg < cc->gdb_num_core_regs) {
         return cpu_gdb_write_register(env, mem_buf, reg);
+    }
 
     for (r = cpu->gdb_regs; r; r = r->next) {
         if (r->base_reg <= reg && reg < r->base_reg + r->num_regs) {
@@ -2012,7 +1981,6 @@ static int gdb_write_register(CPUState *cpu, uint8_t *mem_buf, int reg)
     return 0;
 }
 
-#if !defined(TARGET_XTENSA)
 /* Register a supplemental set of CPU registers.  If g_pos is nonzero it
    specifies the first register number and these registers are included in
    a standard "g" packet.  Direction is relative to gdb, i.e. get_reg is
@@ -2025,7 +1993,6 @@ void gdb_register_coprocessor(CPUState *cpu,
 {
     GDBRegisterState *s;
     GDBRegisterState **p;
-    static int last_reg = NUM_CORE_REGS;
 
     p = &cpu->gdb_regs;
     while (*p) {
@@ -2036,25 +2003,22 @@ void gdb_register_coprocessor(CPUState *cpu,
     }
 
     s = g_new0(GDBRegisterState, 1);
-    s->base_reg = last_reg;
+    s->base_reg = cpu->gdb_num_regs;
     s->num_regs = num_regs;
     s->get_reg = get_reg;
     s->set_reg = set_reg;
     s->xml = xml;
 
     /* Add to end of list.  */
-    last_reg += num_regs;
+    cpu->gdb_num_regs += num_regs;
     *p = s;
     if (g_pos) {
         if (g_pos != s->base_reg) {
             fprintf(stderr, "Error: Bad gdb register numbering for '%s'\n"
                     "Expected %d got %d\n", xml, g_pos, s->base_reg);
-        } else {
-            num_g_regs = last_reg;
         }
     }
 }
-#endif
 
 #ifndef CONFIG_USER_ONLY
 static const int xlat_gdb_type[] = {
@@ -2184,9 +2148,6 @@ static CPUState *find_cpu(uint32_t thread_id)
 
 static int gdb_handle_packet(GDBState *s, const char *line_buf)
 {
-#ifdef TARGET_XTENSA
-    CPUArchState *env;
-#endif
     CPUState *cpu;
     const char *p;
     uint32_t thread;
@@ -2334,11 +2295,8 @@ static int gdb_handle_packet(GDBState *s, const char *line_buf)
         break;
     case 'g':
         cpu_synchronize_state(s->g_cpu);
-#ifdef TARGET_XTENSA
-        env = s->g_cpu->env_ptr;
-#endif
         len = 0;
-        for (addr = 0; addr < num_g_regs; addr++) {
+        for (addr = 0; addr < s->g_cpu->gdb_num_regs; addr++) {
             reg_size = gdb_read_register(s->g_cpu, mem_buf + len, addr);
             len += reg_size;
         }
@@ -2347,13 +2305,10 @@ static int gdb_handle_packet(GDBState *s, const char *line_buf)
         break;
     case 'G':
         cpu_synchronize_state(s->g_cpu);
-#ifdef TARGET_XTENSA
-        env = s->g_cpu->env_ptr;
-#endif
         registers = mem_buf;
         len = strlen(p) / 2;
         hextomem((uint8_t *)registers, p, len);
-        for (addr = 0; addr < num_g_regs && len > 0; addr++) {
+        for (addr = 0; addr < s->g_cpu->gdb_num_regs && len > 0; addr++) {
             reg_size = gdb_write_register(s->g_cpu, registers, addr);
             len -= reg_size;
             registers += reg_size;
diff --git a/include/qom/cpu.h b/include/qom/cpu.h
index daf1835c1a..195fe593ea 100644
--- a/include/qom/cpu.h
+++ b/include/qom/cpu.h
@@ -81,6 +81,7 @@ struct TranslationBlock;
  * #TranslationBlock.
  * @get_phys_page_debug: Callback for obtaining a physical address.
  * @vmsd: State description for migration.
+ * @gdb_num_core_regs: Number of core registers accessible to GDB.
  *
  * Represents a CPU family or model.
  */
@@ -109,7 +110,6 @@ typedef struct CPUClass {
     void (*synchronize_from_tb)(CPUState *cpu, struct TranslationBlock *tb);
     hwaddr (*get_phys_page_debug)(CPUState *cpu, vaddr addr);
 
-    const struct VMStateDescription *vmsd;
     int (*write_elf64_note)(WriteCoreDumpFunction f, CPUState *cpu,
                             int cpuid, void *opaque);
     int (*write_elf64_qemunote)(WriteCoreDumpFunction f, CPUState *cpu,
@@ -118,6 +118,9 @@ typedef struct CPUClass {
                             int cpuid, void *opaque);
     int (*write_elf32_qemunote)(WriteCoreDumpFunction f, CPUState *cpu,
                                 void *opaque);
+
+    const struct VMStateDescription *vmsd;
+    int gdb_num_core_regs;
 } CPUClass;
 
 struct KVMState;
@@ -142,6 +145,7 @@ struct kvm_run;
  * @env_ptr: Pointer to subclass-specific CPUArchState field.
  * @current_tb: Currently executing TB.
  * @gdb_regs: Additional GDB registers.
+ * @gdb_num_regs: Number of total registers accessible to GDB.
  * @next_cpu: Next CPU sharing TB cache.
  * @kvm_fd: vCPU file descriptor for KVM.
  *
@@ -177,6 +181,7 @@ struct CPUState {
     void *env_ptr; /* CPUArchState */
     struct TranslationBlock *current_tb;
     struct GDBRegisterState *gdb_regs;
+    int gdb_num_regs;
     CPUState *next_cpu;
 
     int kvm_fd;
diff --git a/qom/cpu.c b/qom/cpu.c
index 5c45ab5333..2839ddf650 100644
--- a/qom/cpu.c
+++ b/qom/cpu.c
@@ -226,6 +226,14 @@ static void cpu_common_realizefn(DeviceState *dev, Error **errp)
     }
 }
 
+static void cpu_common_initfn(Object *obj)
+{
+    CPUState *cpu = CPU(obj);
+    CPUClass *cc = CPU_GET_CLASS(obj);
+
+    cpu->gdb_num_regs = cc->gdb_num_core_regs;
+}
+
 static int64_t cpu_common_get_arch_id(CPUState *cpu)
 {
     return cpu->cpu_index;
@@ -253,6 +261,7 @@ static const TypeInfo cpu_type_info = {
     .name = TYPE_CPU,
     .parent = TYPE_DEVICE,
     .instance_size = sizeof(CPUState),
+    .instance_init = cpu_common_initfn,
     .abstract = true,
     .class_size = sizeof(CPUClass),
     .class_init = cpu_class_init,
diff --git a/target-alpha/cpu.c b/target-alpha/cpu.c
index c8c8c2c861..cc0f69a84a 100644
--- a/target-alpha/cpu.c
+++ b/target-alpha/cpu.c
@@ -276,6 +276,7 @@ static void alpha_cpu_class_init(ObjectClass *oc, void *data)
     cc->get_phys_page_debug = alpha_cpu_get_phys_page_debug;
     dc->vmsd = &vmstate_alpha_cpu;
 #endif
+    cc->gdb_num_core_regs = 67;
 }
 
 static const TypeInfo alpha_cpu_type_info = {
diff --git a/target-arm/cpu.c b/target-arm/cpu.c
index d3906a4829..f39c19f162 100644
--- a/target-arm/cpu.c
+++ b/target-arm/cpu.c
@@ -828,6 +828,7 @@ static void arm_cpu_class_init(ObjectClass *oc, void *data)
     cc->get_phys_page_debug = arm_cpu_get_phys_page_debug;
     cc->vmsd = &vmstate_arm_cpu;
 #endif
+    cc->gdb_num_core_regs = 26;
 }
 
 static void cpu_register(const ARMCPUInfo *info)
diff --git a/target-cris/cpu.c b/target-cris/cpu.c
index ba095e75a5..31eeddf822 100644
--- a/target-cris/cpu.c
+++ b/target-cris/cpu.c
@@ -258,6 +258,8 @@ static void cris_cpu_class_init(ObjectClass *oc, void *data)
 #ifndef CONFIG_USER_ONLY
     cc->get_phys_page_debug = cris_cpu_get_phys_page_debug;
 #endif
+
+    cc->gdb_num_core_regs = 49;
 }
 
 static const TypeInfo cris_cpu_type_info = {
diff --git a/target-i386/cpu.c b/target-i386/cpu.c
index cd350cb8e4..df9832e151 100644
--- a/target-i386/cpu.c
+++ b/target-i386/cpu.c
@@ -2549,6 +2549,7 @@ static void x86_cpu_common_class_init(ObjectClass *oc, void *data)
     cc->write_elf32_qemunote = x86_cpu_write_elf32_qemunote;
     cc->vmsd = &vmstate_x86_cpu;
 #endif
+    cc->gdb_num_core_regs = CPU_NB_REGS * 2 + 25;
 }
 
 static const TypeInfo x86_cpu_type_info = {
diff --git a/target-lm32/cpu.c b/target-lm32/cpu.c
index ce55e4807d..aa52696cda 100644
--- a/target-lm32/cpu.c
+++ b/target-lm32/cpu.c
@@ -91,6 +91,7 @@ static void lm32_cpu_class_init(ObjectClass *oc, void *data)
     cc->get_phys_page_debug = lm32_cpu_get_phys_page_debug;
     cc->vmsd = &vmstate_lm32_cpu;
 #endif
+    cc->gdb_num_core_regs = 32 + 7;
 }
 
 static const TypeInfo lm32_cpu_type_info = {
diff --git a/target-m68k/cpu.c b/target-m68k/cpu.c
index 988f476257..93200d9964 100644
--- a/target-m68k/cpu.c
+++ b/target-m68k/cpu.c
@@ -194,6 +194,7 @@ static void m68k_cpu_class_init(ObjectClass *c, void *data)
     cc->get_phys_page_debug = m68k_cpu_get_phys_page_debug;
 #endif
     dc->vmsd = &vmstate_m68k_cpu;
+    cc->gdb_num_core_regs = 18;
 }
 
 static void register_cpu_type(const M68kCPUInfo *info)
diff --git a/target-microblaze/cpu.c b/target-microblaze/cpu.c
index 9f10c8c778..758b0cb07d 100644
--- a/target-microblaze/cpu.c
+++ b/target-microblaze/cpu.c
@@ -147,6 +147,7 @@ static void mb_cpu_class_init(ObjectClass *oc, void *data)
 #endif
     dc->vmsd = &vmstate_mb_cpu;
     dc->props = mb_properties;
+    cc->gdb_num_core_regs = 32 + 5;
 }
 
 static const TypeInfo mb_cpu_type_info = {
diff --git a/target-mips/cpu.c b/target-mips/cpu.c
index 4834c86d02..e667fb7b7c 100644
--- a/target-mips/cpu.c
+++ b/target-mips/cpu.c
@@ -104,6 +104,8 @@ static void mips_cpu_class_init(ObjectClass *c, void *data)
     cc->do_unassigned_access = mips_cpu_unassigned_access;
     cc->get_phys_page_debug = mips_cpu_get_phys_page_debug;
 #endif
+
+    cc->gdb_num_core_regs = 73;
 }
 
 static const TypeInfo mips_cpu_type_info = {
diff --git a/target-openrisc/cpu.c b/target-openrisc/cpu.c
index 7718820ecc..9b042e14b0 100644
--- a/target-openrisc/cpu.c
+++ b/target-openrisc/cpu.c
@@ -159,6 +159,7 @@ static void openrisc_cpu_class_init(ObjectClass *oc, void *data)
     cc->get_phys_page_debug = openrisc_cpu_get_phys_page_debug;
     dc->vmsd = &vmstate_openrisc_cpu;
 #endif
+    cc->gdb_num_core_regs = 32 + 3;
 }
 
 static void cpu_register(const OpenRISCCPUInfo *info)
diff --git a/target-ppc/translate_init.c b/target-ppc/translate_init.c
index 0b0844f467..91161939c0 100644
--- a/target-ppc/translate_init.c
+++ b/target-ppc/translate_init.c
@@ -8461,6 +8461,8 @@ static void ppc_cpu_class_init(ObjectClass *oc, void *data)
 #ifndef CONFIG_USER_ONLY
     cc->get_phys_page_debug = ppc_cpu_get_phys_page_debug;
 #endif
+
+    cc->gdb_num_core_regs = 71;
 }
 
 static const TypeInfo ppc_cpu_type_info = {
diff --git a/target-s390x/cpu.c b/target-s390x/cpu.c
index cb89d1a46b..8f99d7c86c 100644
--- a/target-s390x/cpu.c
+++ b/target-s390x/cpu.c
@@ -177,6 +177,7 @@ static void s390_cpu_class_init(ObjectClass *oc, void *data)
     cc->get_phys_page_debug = s390_cpu_get_phys_page_debug;
 #endif
     dc->vmsd = &vmstate_s390_cpu;
+    cc->gdb_num_core_regs = S390_NUM_REGS;
 }
 
 static const TypeInfo s390_cpu_type_info = {
diff --git a/target-sh4/cpu.c b/target-sh4/cpu.c
index 51a77576fb..35f0535436 100644
--- a/target-sh4/cpu.c
+++ b/target-sh4/cpu.c
@@ -290,6 +290,7 @@ static void superh_cpu_class_init(ObjectClass *oc, void *data)
     cc->get_phys_page_debug = superh_cpu_get_phys_page_debug;
 #endif
     dc->vmsd = &vmstate_sh_cpu;
+    cc->gdb_num_core_regs = 59;
 }
 
 static const TypeInfo superh_cpu_type_info = {
diff --git a/target-sparc/cpu.c b/target-sparc/cpu.c
index d1d03396ef..388a632d18 100644
--- a/target-sparc/cpu.c
+++ b/target-sparc/cpu.c
@@ -791,6 +791,12 @@ static void sparc_cpu_class_init(ObjectClass *oc, void *data)
     cc->do_unassigned_access = sparc_cpu_unassigned_access;
     cc->get_phys_page_debug = sparc_cpu_get_phys_page_debug;
 #endif
+
+#if defined(TARGET_SPARC64) && !defined(TARGET_ABI32)
+    cc->gdb_num_core_regs = 86;
+#else
+    cc->gdb_num_core_regs = 72;
+#endif
 }
 
 static const TypeInfo sparc_cpu_type_info = {
diff --git a/target-xtensa/cpu.c b/target-xtensa/cpu.c
index 5a39971d2c..560fa0c058 100644
--- a/target-xtensa/cpu.c
+++ b/target-xtensa/cpu.c
@@ -85,8 +85,11 @@ static ObjectClass *xtensa_cpu_class_by_name(const char *cpu_model)
 
 static void xtensa_cpu_realizefn(DeviceState *dev, Error **errp)
 {
+    CPUState *cs = CPU(dev);
     XtensaCPUClass *xcc = XTENSA_CPU_GET_CLASS(dev);
 
+    cs->gdb_num_regs = xcc->config->gdb_regmap.num_regs;
+
     xcc->parent_realize(dev, errp);
 }
 
diff --git a/target-xtensa/helper.c b/target-xtensa/helper.c
index e3098798af..a0f9993b2d 100644
--- a/target-xtensa/helper.c
+++ b/target-xtensa/helper.c
@@ -37,10 +37,18 @@ static struct XtensaConfigList *xtensa_cores;
 
 static void xtensa_core_class_init(ObjectClass *oc, void *data)
 {
+    CPUClass *cc = CPU_CLASS(oc);
     XtensaCPUClass *xcc = XTENSA_CPU_CLASS(oc);
     const XtensaConfig *config = data;
 
     xcc->config = config;
+
+    /* Use num_core_regs to see only non-privileged registers in an unmodified
+     * gdb. Use num_regs to see all registers. gdb modification is required
+     * for that: reset bit 0 in the 'flags' field of the registers definitions
+     * in the gdb/xtensa-config.c inside gdb source tree or inside gdb overlay.
+     */
+    cc->gdb_num_core_regs = config->gdb_regmap.num_regs;
 }
 
 void xtensa_register_core(XtensaConfigList *node)