1 /*
2 * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
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7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
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23 */
24
25 #ifndef SHARE_RUNTIME_ABSTRACT_VM_VERSION_HPP
26 #define SHARE_RUNTIME_ABSTRACT_VM_VERSION_HPP
27
28 #include "memory/allStatic.hpp" // For declaration of class AllStatic
29 #include "utilities/globalDefinitions.hpp"
30
31 typedef enum {
32 NoDetectedVirtualization,
33 XenHVM,
34 XenPVHVM, // mix-mode on Linux aarch64
35 KVM,
36 VMWare,
37 HyperV,
38 HyperVRole,
39 PowerVM, // on AIX or Linux ppc64(le)
40 PowerFullPartitionMode, // on Linux ppc64(le)
41 PowerKVM
42 } VirtualizationType;
43
44 class outputStream;
45 class stringStream;
46 enum class vmIntrinsicID;
47
48 // Abstract_VM_Version provides information about the VM.
49
50 class Abstract_VM_Version: AllStatic {
51 friend class VMStructs;
52 friend class JVMCIVMStructs;
53
54 protected:
55 static const char* _s_vm_release;
56 static const char* _s_internal_vm_info_string;
57
58 // CPU feature flags, can be affected by VM settings.
59 static uint64_t _features;
60
61 static const char* _features_string;
62
63 static const char* _cpu_info_string;
64
65 // Original CPU feature flags, not affected by VM settings.
66 static uint64_t _cpu_features;
67
68 // These are set by machine-dependent initializations
69 #ifndef SUPPORTS_NATIVE_CX8
70 static bool _supports_cx8;
71 #endif
72 static bool _supports_atomic_getset4;
73 static bool _supports_atomic_getset8;
74 static bool _supports_atomic_getadd4;
75 static bool _supports_atomic_getadd8;
76 static unsigned int _logical_processors_per_package;
77 static unsigned int _L1_data_cache_line_size;
78 static int _vm_major_version;
79 static int _vm_minor_version;
80 static int _vm_security_version;
81 static int _vm_patch_version;
82 static int _vm_build_number;
83 static unsigned int _data_cache_line_flush_size;
84
85 public:
86
87 static VirtualizationType _detected_virtualization;
88
89 // Called as part of the runtime services initialization which is
90 // called from the management module initialization (via init_globals())
91 // after argument parsing and attaching of the main thread has
92 // occurred. Examines a variety of the hardware capabilities of
93 // the platform to determine which features can be used to execute the
94 // program.
95 static void initialize() { }
96
97 // This allows for early initialization of VM_Version information
98 // that may be needed later in the initialization sequence but before
99 // full VM_Version initialization is possible. It can not depend on any
100 // other part of the VM being initialized when called. Platforms that
101 // need to specialize this define VM_Version::early_initialize().
102 static void early_initialize() { }
103
104 // Called to initialize VM variables needing initialization
105 // after command line parsing. Platforms that need to specialize
106 // this should define VM_Version::init_before_ergo().
107 static void init_before_ergo() {}
108
109 // Name
110 static const char* vm_name();
111 // Vendor
112 static const char* vm_vendor();
113 // VM version information string printed by launcher (java -version)
114 static const char* vm_info_string();
115 static const char* vm_release();
116 static const char* vm_platform_string();
117 static const char* vm_variant();
118
119 static int vm_major_version() { return _vm_major_version; }
120 static int vm_minor_version() { return _vm_minor_version; }
121 static int vm_security_version() { return _vm_security_version; }
122 static int vm_patch_version() { return _vm_patch_version; }
123 static int vm_build_number() { return _vm_build_number; }
124
125 // Gets the jvm_version_info.jvm_version
126 static unsigned int jvm_version();
127
128 // Internal version providing additional build information
129 static const char* internal_vm_info_string();
130 static const char* jdk_debug_level();
131 static const char* printable_jdk_debug_level();
132
133 static const char* features_string() { return _features_string; }
134
135 static const char* cpu_info_string() { return _cpu_info_string; }
136
137 static VirtualizationType get_detected_virtualization() {
138 return _detected_virtualization;
139 }
140
141 // platforms that need to specialize this
142 // define VM_Version::print_platform_virtualization_info()
143 static void print_platform_virtualization_info(outputStream*) { }
144
145 // does HW support an 8-byte compare-exchange operation?
146 // Required to be true but still dynamically checked at runtime
147 // for platforms that don't set SUPPORTS_NATIVE_CX8
148 static bool supports_cx8() {
149 #ifdef SUPPORTS_NATIVE_CX8
150 return true;
151 #else
152 return _supports_cx8;
153 #endif
154 }
155 // does HW support atomic get-and-set or atomic get-and-add? Used
156 // to guide intrinsification decisions for Unsafe atomic ops
157 static bool supports_atomic_getset4() {return _supports_atomic_getset4;}
158 static bool supports_atomic_getset8() {return _supports_atomic_getset8;}
159 static bool supports_atomic_getadd4() {return _supports_atomic_getadd4;}
160 static bool supports_atomic_getadd8() {return _supports_atomic_getadd8;}
161
162 static unsigned int logical_processors_per_package() {
163 return _logical_processors_per_package;
164 }
165
166 static unsigned int L1_data_cache_line_size() {
167 return _L1_data_cache_line_size;
168 }
169
170 // the size in bytes of a data cache line flushed by a flush
171 // operation which should be a power of two or zero if cache line
172 // writeback is not supported by the current os_cpu combination
173 static unsigned int data_cache_line_flush_size() {
174 return _data_cache_line_flush_size;
175 }
176
177 // returns true if and only if cache line writeback is supported
178 static bool supports_data_cache_line_flush() {
179 return _data_cache_line_flush_size != 0;
180 }
181
182 // Denominator for computing default ParallelGCThreads for machines with
183 // a large number of cores.
184 static uint parallel_worker_threads_denominator() { return 8; }
185
186 // Does this CPU support spin wait instruction?
187 static bool supports_on_spin_wait() { return false; }
188
189 // Does platform support fast class initialization checks for static methods?
190 static bool supports_fast_class_init_checks() { return false; }
191
192 // Does platform support stack watermark barriers for concurrent stack processing?
193 constexpr static bool supports_stack_watermark_barrier() { return false; }
194
195 // Is recursive lightweight locking implemented for this platform?
196 constexpr static bool supports_recursive_lightweight_locking() { return false; }
197
198 // Does platform support secondary supers table lookup?
199 constexpr static bool supports_secondary_supers_table() { return false; }
200
201 // Does platform support float16 instructions?
202 static bool supports_float16() { return false; }
203
204 // Does this CPU support this intrinsic?
205 static bool is_intrinsic_supported(vmIntrinsicID id) { return true; }
206
207 static bool profile_all_receivers_at_type_check() { return true; }
208
209 static bool print_matching_lines_from_file(const char* filename, outputStream* st, const char* keywords_to_match[]);
210
211 protected:
212 // VM_Version statics
213 static const size_t CPU_TYPE_DESC_BUF_SIZE = 256;
214 static const size_t CPU_DETAILED_DESC_BUF_SIZE = 4096;
215
216 static int _no_of_threads;
217 static int _no_of_cores;
218 static int _no_of_sockets;
219 static bool _initialized;
220 static char _cpu_name[CPU_TYPE_DESC_BUF_SIZE];
221 static char _cpu_desc[CPU_DETAILED_DESC_BUF_SIZE];
222
223 public:
224 static int number_of_threads(void);
225 static int number_of_cores(void);
226 static int number_of_sockets(void);
227
228 static const char* cpu_name(void);
229 static const char* cpu_description(void);
230
231 static void get_cpu_features_name(void* features_buffer, stringStream& ss) { return; }
232 static void get_missing_features_name(void* features_buffer, stringStream& ss) { return; }
233
234 // Returns number of bytes required to store cpu features representation
235 static int cpu_features_size() { return 0; }
236
237 // Stores arch dependent cpu features representation in the provided buffer.
238 // Size of the buffer must be same as returned by cpu_features_size()
239 static void store_cpu_features(void* buf) { return; }
240
241 // features_to_test is an opaque object that stores arch specific representation of cpu features
242 static bool supports_features(void* features_to_test) { return false; };
243 };
244
245 #endif // SHARE_RUNTIME_ABSTRACT_VM_VERSION_HPP