gdb/nat/x86-xstate.c

   1 /* x86 XSAVE extended state functions.
   2
   3    Copyright (C) 2022-2023 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 #include "gdbsupport/common-defs.h"
  21 #include "gdbsupport/x86-xstate.h"
  22 #include "nat/x86-cpuid.h"
  23 #include "nat/x86-xstate.h"
  24
  25 /* Fetch the offset of a specific XSAVE extended region.  */
  26
  27 static int
  28 xsave_feature_offset (uint64_t xcr0, int feature)
  29 {
  30   uint32_t ebx;
  31
  32   if ((xcr0 & (1ULL << feature)) == 0)
  33     return 0;
  34
  35   if (!x86_cpuid_count (0xd, feature, nullptr, &ebx, nullptr, nullptr))
  36     return 0;
  37   return ebx;
  38 }
  39
  40 /* See x86-xstate.h.  */
  41
  42 int
  43 x86_xsave_length ()
  44 {
  45   uint32_t ebx;
  46
  47   if (!x86_cpuid_count (0xd, 0, nullptr, &ebx, nullptr, nullptr))
  48     return 0;
  49   return ebx;
  50 }
  51
  52 /* See x86-xstate.h.  */
  53
  54 x86_xsave_layout
  55 x86_fetch_xsave_layout (uint64_t xcr0, int len)
  56 {
  57   x86_xsave_layout layout;
  58   layout.sizeof_xsave = len;
  59   layout.avx_offset = xsave_feature_offset (xcr0, X86_XSTATE_AVX_ID);
  60   layout.bndregs_offset = xsave_feature_offset (xcr0, X86_XSTATE_BNDREGS_ID);
  61   layout.bndcfg_offset = xsave_feature_offset (xcr0, X86_XSTATE_BNDCFG_ID);
  62   layout.k_offset = xsave_feature_offset (xcr0, X86_XSTATE_K_ID);
  63   layout.zmm_h_offset = xsave_feature_offset (xcr0, X86_XSTATE_ZMM_H_ID);
  64   layout.zmm_offset = xsave_feature_offset (xcr0, X86_XSTATE_ZMM_ID);
  65   layout.pkru_offset = xsave_feature_offset (xcr0, X86_XSTATE_PKRU_ID);
  66   return layout;
  67 }