target/i386: gdbstub: only write CR0/CR2/CR3/EFER for sysemu

Signed-off-by: Claudio Fontana <cfontana@suse.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210322132800.7470-21-cfontana@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

target/i386/gdbstub.c

@@ -351,22 +351,30 @@ int x86_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
 
         case IDX_CTL_CR0_REG:
             len = gdb_write_reg_cs64(env->hflags, mem_buf, &tmp);
+#ifndef CONFIG_USER_ONLY
             cpu_x86_update_cr0(env, tmp);
+#endif
             return len;
 
         case IDX_CTL_CR2_REG:
             len = gdb_write_reg_cs64(env->hflags, mem_buf, &tmp);
+#ifndef CONFIG_USER_ONLY
             env->cr[2] = tmp;
+#endif
             return len;
 
         case IDX_CTL_CR3_REG:
             len = gdb_write_reg_cs64(env->hflags, mem_buf, &tmp);
+#ifndef CONFIG_USER_ONLY
             cpu_x86_update_cr3(env, tmp);
+#endif
             return len;
 
         case IDX_CTL_CR4_REG:
             len = gdb_write_reg_cs64(env->hflags, mem_buf, &tmp);
+#ifndef CONFIG_USER_ONLY
             cpu_x86_update_cr4(env, tmp);
+#endif
             return len;
 
         case IDX_CTL_CR8_REG:
@@ -378,7 +386,9 @@ int x86_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
 
         case IDX_CTL_EFER_REG:
             len = gdb_write_reg_cs64(env->hflags, mem_buf, &tmp);
+#ifndef CONFIG_USER_ONLY
             cpu_load_efer(env, tmp);
+#endif
             return len;
         }
     }