From 6bc12fd04243a5bfe28bc5d6ed8b0a7ed40f5de4 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Wed, 17 May 2023 21:12:08 -0700 Subject: util: Add cpuinfo-i386.c MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add cpuinfo.h for i386 and x86_64, and the initialization for that in util/. Populate that with a slightly altered copy of the tcg host probing code. Other uses of cpuid.h will be adjusted one patch at a time. Reviewed-by: Alex Bennée Reviewed-by: Juan Quintela Signed-off-by: Richard Henderson --- util/cpuinfo-i386.c | 97 +++++++++++++++++++++++++++++++++++++++++++++++++++++ util/meson.build | 4 +++ 2 files changed, 101 insertions(+) create mode 100644 util/cpuinfo-i386.c (limited to 'util') diff --git a/util/cpuinfo-i386.c b/util/cpuinfo-i386.c new file mode 100644 index 0000000..434319a --- /dev/null +++ b/util/cpuinfo-i386.c @@ -0,0 +1,97 @@ +/* + * SPDX-License-Identifier: GPL-2.0-or-later + * Host specific cpu indentification for x86. + */ + +#include "qemu/osdep.h" +#include "host/cpuinfo.h" +#ifdef CONFIG_CPUID_H +# include "qemu/cpuid.h" +#endif + +unsigned cpuinfo; + +/* Called both as constructor and (possibly) via other constructors. */ +unsigned __attribute__((constructor)) cpuinfo_init(void) +{ + unsigned info = cpuinfo; + + if (info) { + return info; + } + +#ifdef CONFIG_CPUID_H + unsigned max, a, b, c, d, b7 = 0, c7 = 0; + + max = __get_cpuid_max(0, 0); + + if (max >= 7) { + __cpuid_count(7, 0, a, b7, c7, d); + info |= (b7 & bit_BMI ? CPUINFO_BMI1 : 0); + info |= (b7 & bit_BMI2 ? CPUINFO_BMI2 : 0); + } + + if (max >= 1) { + __cpuid(1, a, b, c, d); + + info |= (d & bit_CMOV ? CPUINFO_CMOV : 0); + info |= (d & bit_SSE2 ? CPUINFO_SSE2 : 0); + info |= (c & bit_SSE4_1 ? CPUINFO_SSE4 : 0); + info |= (c & bit_MOVBE ? CPUINFO_MOVBE : 0); + info |= (c & bit_POPCNT ? CPUINFO_POPCNT : 0); + + /* For AVX features, we must check available and usable. */ + if ((c & bit_AVX) && (c & bit_OSXSAVE)) { + unsigned bv = xgetbv_low(0); + + if ((bv & 6) == 6) { + info |= CPUINFO_AVX1; + info |= (b7 & bit_AVX2 ? CPUINFO_AVX2 : 0); + + if ((bv & 0xe0) == 0xe0) { + info |= (b7 & bit_AVX512F ? CPUINFO_AVX512F : 0); + info |= (b7 & bit_AVX512VL ? CPUINFO_AVX512VL : 0); + info |= (b7 & bit_AVX512BW ? CPUINFO_AVX512BW : 0); + info |= (b7 & bit_AVX512DQ ? CPUINFO_AVX512DQ : 0); + info |= (c7 & bit_AVX512VBMI2 ? CPUINFO_AVX512VBMI2 : 0); + } + + /* + * The Intel SDM has added: + * Processors that enumerate support for Intel® AVX + * (by setting the feature flag CPUID.01H:ECX.AVX[bit 28]) + * guarantee that the 16-byte memory operations performed + * by the following instructions will always be carried + * out atomically: + * - MOVAPD, MOVAPS, and MOVDQA. + * - VMOVAPD, VMOVAPS, and VMOVDQA when encoded with VEX.128. + * - VMOVAPD, VMOVAPS, VMOVDQA32, and VMOVDQA64 when encoded + * with EVEX.128 and k0 (masking disabled). + * Note that these instructions require the linear addresses + * of their memory operands to be 16-byte aligned. + * + * AMD has provided an even stronger guarantee that processors + * with AVX provide 16-byte atomicity for all cachable, + * naturally aligned single loads and stores, e.g. MOVDQU. + * + * See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104688 + */ + __cpuid(0, a, b, c, d); + if (c == signature_INTEL_ecx || c == signature_AMD_ecx) { + info |= CPUINFO_ATOMIC_VMOVDQA; + } + } + } + } + + max = __get_cpuid_max(0x8000000, 0); + if (max >= 1) { + __cpuid(0x80000001, a, b, c, d); + info |= (c & bit_LZCNT ? CPUINFO_LZCNT : 0); + } +#endif + + info |= CPUINFO_ALWAYS; + cpuinfo = info; + return info; +} diff --git a/util/meson.build b/util/meson.build index e1f1c39..b3be9fa 100644 --- a/util/meson.build +++ b/util/meson.build @@ -108,3 +108,7 @@ if have_block endif util_ss.add(when: 'CONFIG_LINUX', if_true: files('vfio-helpers.c')) endif + +if cpu in ['x86', 'x86_64'] + util_ss.add(files('cpuinfo-i386.c')) +endif -- cgit v1.1