gdbsupport/x86-xstate.h

   1 /* Common code for x86 XSAVE extended state.
   2
   3    Copyright (C) 2010-2024 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef COMMON_X86_XSTATE_H
  21 #define COMMON_X86_XSTATE_H
  22
  23 /* The extended state feature IDs in the state component bitmap.  */
  24 #define X86_XSTATE_X87_ID       0
  25 #define X86_XSTATE_SSE_ID       1
  26 #define X86_XSTATE_AVX_ID       2
  27 #define X86_XSTATE_K_ID         5
  28 #define X86_XSTATE_ZMM_H_ID     6
  29 #define X86_XSTATE_ZMM_ID       7
  30 #define X86_XSTATE_PKRU_ID      9
  31
  32 /* The extended state feature bits.  */
  33 #define X86_XSTATE_X87          (1ULL << X86_XSTATE_X87_ID)
  34 #define X86_XSTATE_SSE          (1ULL << X86_XSTATE_SSE_ID)
  35 #define X86_XSTATE_AVX          (1ULL << X86_XSTATE_AVX_ID)
  36
  37 /* AVX 512 adds three feature bits.  All three must be enabled.  */
  38 #define X86_XSTATE_K            (1ULL << X86_XSTATE_K_ID)
  39 #define X86_XSTATE_ZMM_H        (1ULL << X86_XSTATE_ZMM_H_ID)
  40 #define X86_XSTATE_ZMM          (1ULL << X86_XSTATE_ZMM_ID)
  41 #define X86_XSTATE_AVX512       (X86_XSTATE_K | X86_XSTATE_ZMM_H \
  42                                  | X86_XSTATE_ZMM)
  43
  44 #define X86_XSTATE_PKRU         (1ULL << X86_XSTATE_PKRU_ID)
  45
  46 /* Total size of the XSAVE area extended region and offsets of
  47    register states within the region.  Offsets are set to 0 to
  48    indicate the absence of the associated registers.  */
  49
  50 struct x86_xsave_layout
  51 {
  52   int sizeof_xsave = 0;
  53   int avx_offset = 0;
  54   int k_offset = 0;
  55   int zmm_h_offset = 0;
  56   int zmm_offset = 0;
  57   int pkru_offset = 0;
  58 };
  59
  60 constexpr bool operator== (const x86_xsave_layout &lhs,
  61                            const x86_xsave_layout &rhs)
  62 {
  63   return lhs.sizeof_xsave == rhs.sizeof_xsave
  64     && lhs.avx_offset == rhs.avx_offset
  65     && lhs.k_offset == rhs.k_offset
  66     && lhs.zmm_h_offset == rhs.zmm_h_offset
  67     && lhs.zmm_offset == rhs.zmm_offset
  68     && lhs.pkru_offset == rhs.pkru_offset;
  69 }
  70
  71 constexpr bool operator!= (const x86_xsave_layout &lhs,
  72                            const x86_xsave_layout &rhs)
  73 {
  74   return !(lhs == rhs);
  75 }
  76
  77
  78 /* Supported mask and size of the extended state.  */
  79 #define X86_XSTATE_X87_MASK     X86_XSTATE_X87
  80 #define X86_XSTATE_SSE_MASK     (X86_XSTATE_X87 | X86_XSTATE_SSE)
  81 #define X86_XSTATE_AVX_MASK     (X86_XSTATE_SSE_MASK | X86_XSTATE_AVX)
  82 #define X86_XSTATE_AVX_AVX512_MASK      (X86_XSTATE_AVX_MASK | X86_XSTATE_AVX512)
  83 #define X86_XSTATE_AVX_AVX512_PKU_MASK  (X86_XSTATE_AVX_MASK\
  84                                         | X86_XSTATE_AVX512 | X86_XSTATE_PKRU)
  85
  86 #define X86_XSTATE_ALL_MASK             (X86_XSTATE_AVX_AVX512_PKU_MASK)
  87
  88
  89 #define X86_XSTATE_SSE_SIZE     576
  90 #define X86_XSTATE_AVX_SIZE     832
  91
  92
  93 #define HAS_AVX(XCR0) (((XCR0) & X86_XSTATE_AVX) != 0)
  94 #define HAS_AVX512(XCR0) (((XCR0) & X86_XSTATE_AVX512) != 0)
  95 #define HAS_PKRU(XCR0) (((XCR0) & X86_XSTATE_PKRU) != 0)
  96
  97 /* Initial value for fctrl register, as defined in the X86 manual, and
  98    confirmed in the (Linux) kernel source.  When the x87 floating point
  99    feature is not enabled in an inferior we use this as the value of the
 100    fcrtl register.  */
 101
 102 #define I387_FCTRL_INIT_VAL 0x037f
 103
 104 /* Initial value for mxcsr register.  When the avx and sse floating point
 105    features are not enabled in an inferior we use this as the value of the
 106    mxcsr register.  */
 107
 108 #define I387_MXCSR_INIT_VAL 0x1f80
 109
 110 /* Format of XSAVE extended state is:
 111         struct
 112         {
 113           fxsave_bytes[0..463]
 114           sw_usable_bytes[464..511]
 115           xstate_hdr_bytes[512..575]
 116           extended state regions (AVX, MPX, AVX512, PKRU, etc.)
 117         };
 118
 119   Same memory layout will be used for the coredump NT_X86_XSTATE
 120   representing the XSAVE extended state registers.
 121
 122   The first 8 bytes of the sw_usable_bytes[464..467] is the OS enabled
 123   extended state mask, which is the same as the extended control register
 124   0 (the XFEATURE_ENABLED_MASK register), XCR0.  We can use this mask
 125   together with the mask saved in the xstate_hdr_bytes to determine what
 126   states the processor/OS supports and what state, used or initialized,
 127   the process/thread is in.  */
 128 #define I386_LINUX_XSAVE_XCR0_OFFSET 464
 129
 130 #endif /* COMMON_X86_XSTATE_H */