> -----Original Message-----
> From: Yichen Wang <yichen.w...@bytedance.com>
> Sent: Friday, July 12, 2024 5:53 AM
> To: Paolo Bonzini <pbonz...@redhat.com>; Marc-André Lureau
> <marcandre.lur...@redhat.com>; Daniel P. Berrangé <berra...@redhat.com>;
> Thomas Huth <th...@redhat.com>; Philippe Mathieu-Daudé
> <phi...@linaro.org>; Peter Xu <pet...@redhat.com>; Fabiano Rosas
> <faro...@suse.de>; Eric Blake <ebl...@redhat.com>; Markus Armbruster
> <arm...@redhat.com>; Michael S. Tsirkin <m...@redhat.com>; Cornelia Huck
> <coh...@redhat.com>; qemu-devel@nongnu.org
> Cc: Hao Xiang <hao.xi...@linux.dev>; Liu, Yuan1 <yuan1....@intel.com>;
> Kumar, Shivam <shivam.kum...@nutanix.com>; Ho-Ren (Jack) Chuang
> <horenchu...@bytedance.com>; Wang, Yichen <yichen.w...@bytedance.com>
> Subject: [PATCH v5 01/13] meson: Introduce new instruction set enqcmd to
> the build system.
>
> From: Hao Xiang <hao.xi...@linux.dev>
>
> Enable instruction set enqcmd in build.
>
> Signed-off-by: Hao Xiang <hao.xi...@linux.dev>
> Signed-off-by: Yichen Wang <yichen.w...@bytedance.com>
> ---
> meson.build | 14 ++++++++++++++
> meson_options.txt | 2 ++
> scripts/meson-buildoptions.sh | 3 +++
> 3 files changed, 19 insertions(+)
>
> diff --git a/meson.build b/meson.build
> index 6a93da48e1..af650cfabf 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -2893,6 +2893,20 @@ config_host_data.set('CONFIG_AVX512BW_OPT',
> get_option('avx512bw') \
> int main(int argc, char *argv[]) { return bar(argv[0]); }
> '''), error_message: 'AVX512BW not available').allowed())
>
> +config_host_data.set('CONFIG_DSA_OPT', get_option('enqcmd') \
> + .require(have_cpuid_h, error_message: 'cpuid.h not available, cannot
> enable ENQCMD') \
> + .require(cc.links('''
> + #include <stdint.h>
> + #include <cpuid.h>
> + #include <immintrin.h>
> + static int __attribute__((target("enqcmd"))) bar(void *a) {
> + uint64_t dst[8] = { 0 };
> + uint64_t src[8] = { 0 };
> + return _enqcmd(dst, src);
> + }
> + int main(int argc, char *argv[]) { return bar(argv[argc - 1]); }
> + '''), error_message: 'ENQCMD not available').allowed())
> +
How about using cpuid instruction to dynamically detect enqcmd and movdir64b
instructions?
My reasons are as follows
1. enqcmd/movdir64b and DSA devices are used together. DSA devices are
dynamically
detected, so enqcmd can also dynamically detect.
Simple code for dynamically detect movdir64b and enqcmd
bool check_dsa_instructions(void) {
uint32_t eax, ebx, ecx, edx;
bool movedirb_enabled;
bool enqcmd_enabled;
cpuid(0x07, 0x0, &eax, &ebx, &ecx, &edx);
movedirb_enabled = (ecx >> 28) & 0x1;
if (!movedirb_enabled) {
return false;
}
enqcmd_enabled = (ecx >> 29) & 0x1;
if (!enqcmd_enabled) {
return false;
}
return true;
}
https://cdrdv2-public.intel.com/819680/architecture-instruction-set-extensions-programming-reference.pdf
2. The enqcmd/movdir64b are new instructions, I checked they are integrated
into GCC10
However, users do not need gcc10 or higher to use two instructions.
Simple code to implement enqcmd
static inline int enqcmd(volatile void *reg, struct dsa_hw_desc *desc)
{
uint8_t retry;
asm volatile (".byte 0xf2, 0x0f, 0x38, 0xf8, 0x02\t\n"
"setz %0\t\n":"=r" (retry):"a"(reg), "d"(desc));
return (int)retry;
}
file:///C:/Users/yliu80/Downloads/353216-data-streaming-accelerator-user-guide-002.pdf
> # For both AArch64 and AArch32, detect if builtins are available.
> config_host_data.set('CONFIG_ARM_AES_BUILTIN', cc.compiles('''
> #include <arm_neon.h>
> diff --git a/meson_options.txt b/meson_options.txt
> index 0269fa0f16..4ed820bb8d 100644
> --- a/meson_options.txt
> +++ b/meson_options.txt
> @@ -121,6 +121,8 @@ option('avx2', type: 'feature', value: 'auto',
> description: 'AVX2 optimizations')
> option('avx512bw', type: 'feature', value: 'auto',
> description: 'AVX512BW optimizations')
> +option('enqcmd', type: 'feature', value: 'disabled',
> + description: 'ENQCMD optimizations')
> option('keyring', type: 'feature', value: 'auto',
> description: 'Linux keyring support')
> option('libkeyutils', type: 'feature', value: 'auto',
> diff --git a/scripts/meson-buildoptions.sh b/scripts/meson-buildoptions.sh
> index cfadb5ea86..280e117687 100644
> --- a/scripts/meson-buildoptions.sh
> +++ b/scripts/meson-buildoptions.sh
> @@ -95,6 +95,7 @@ meson_options_help() {
> printf "%s\n" ' auth-pam PAM access control'
> printf "%s\n" ' avx2 AVX2 optimizations'
> printf "%s\n" ' avx512bw AVX512BW optimizations'
> + printf "%s\n" ' enqcmd ENQCMD optimizations'
> printf "%s\n" ' blkio libblkio block device driver'
> printf "%s\n" ' bochs bochs image format support'
> printf "%s\n" ' bpf eBPF support'
> @@ -239,6 +240,8 @@ _meson_option_parse() {
> --disable-avx2) printf "%s" -Davx2=disabled ;;
> --enable-avx512bw) printf "%s" -Davx512bw=enabled ;;
> --disable-avx512bw) printf "%s" -Davx512bw=disabled ;;
> + --enable-enqcmd) printf "%s" -Denqcmd=enabled ;;
> + --disable-enqcmd) printf "%s" -Denqcmd=disabled ;;
> --enable-gcov) printf "%s" -Db_coverage=true ;;
> --disable-gcov) printf "%s" -Db_coverage=false ;;
> --enable-lto) printf "%s" -Db_lto=true ;;
> --
> Yichen Wang
