From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 528B0A05A0; Tue, 21 Apr 2020 22:41:42 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 2A4501D445; Tue, 21 Apr 2020 22:41:42 +0200 (CEST) Received: from mail-qt1-f196.google.com (mail-qt1-f196.google.com [209.85.160.196]) by dpdk.org (Postfix) with ESMTP id 7DCB61D440 for ; Tue, 21 Apr 2020 22:41:41 +0200 (CEST) Received: by mail-qt1-f196.google.com with SMTP id 71so12751909qtc.12 for ; Tue, 21 Apr 2020 13:41:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=Lo8+d918gZimIDGjN/gkv+6HIWmTeGcYnnMcht/KXPo=; b=lbWrsLvB0bghZViekIXQdbgGtdKlrPnRB2Rfyc4kqcBl2o9YAC+wAx98SSGmQ3hti3 RjHurLxKWdygxtMa2n4eRsFEIX1W9spN2KKpAck4d69kO9ZUAI9cTBLxuTpXehIJXw5K Vo7hbgmn+198qEkcrAnifAhIqQjnlxcuDMOBALkwScol5jihImiG4MfubQ79Uwju8CzY ApxjkyHqrgdTCP2SN4a6eWqWfKpujyAS+MGdc81JNZxtMACYmTv/G3X/MH8Ml49cqCi4 ex4JL20q6rFJwvtJZGsKvYhwYe/vY5PWegjQPnuGuFvMGHProhF06nih+auY1hcTi3GZ S/Fw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-transfer-encoding; bh=Lo8+d918gZimIDGjN/gkv+6HIWmTeGcYnnMcht/KXPo=; b=EBQfORBH/9Uflw7rTmcUL2g83kQjXQgOriRUd21aTPM4/GbmC05IFM1HjLO/WhDUa5 sHYYg8Gs1s+hUkpM9cv20y0bk5ccorcrBsIl37SyjtaY8CTPI2xi8l+k2ZX77uWPZkZR mfm/N+bnAHHIiSO8md05mVlhRYQi5ZE7FIcfqwjarjHavCE2HvZOiC/5Up1Ut3TnceiW 8GN9XVMIV1zHawjAYmsMW/Ym5MMZYDMyXiewnwifj2I9FmTzcDKerfb0ybA2x4dBuG0p jQRqrbYVFA8eokQ6OaMOob+77tqJ0Y3mn4ZIP1ntwHAx97d0yd6hQJmBHIBpXyVKzcWJ GPdg== X-Gm-Message-State: AGi0PuY/ELEw9BmwOyJ8gGAEDCXujQumi9j95zwwKL+3qrWQArLqO4nF X7RnLYE8DwI0gmHoNeVFR7oU1tdeaTw= X-Google-Smtp-Source: APiQypIo1O68LZq1ZhoIbwBy+PjClMZSZfIAPPOXoxMIA6kdgPol89wQMHlSH8A+Xp1dG7RtaPWpvQ== X-Received: by 2002:ac8:724b:: with SMTP id l11mr9607437qtp.35.1587501700652; Tue, 21 Apr 2020 13:41:40 -0700 (PDT) Received: from localhost.localdomain ([168.121.99.161]) by smtp.gmail.com with ESMTPSA id d23sm2431067qkj.26.2020.04.21.13.41.38 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 21 Apr 2020 13:41:40 -0700 (PDT) From: Dan Gora To: dev@dpdk.org, Thomas Monjalon , =?UTF-8?q?Mattias=20R=C3=B6nnblom?= Cc: David Marchand , Jerin Jacob , Dan Gora Date: Tue, 21 Apr 2020 17:41:14 -0300 Message-Id: <20200421204115.31950-2-dg@adax.com> X-Mailer: git-send-email 2.24.1.425.g7034cd094b In-Reply-To: <20200421204115.31950-1-dg@adax.com> References: <20200421195446.1730-1-dg@adax.com> <20200421204115.31950-1-dg@adax.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Subject: [dpdk-dev] [PATCH v2 1/2] eal: check for rdseed at run time for random seed X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" Instead of enabling the rdseed instruction for the random number generator entropy source at compilation time, determine if the instruction can be used at run time. The DPDK build is updated to check that the compiler can generate the rdseed instruction even if the compilation platform does not natively support it. If so, the -mrdseed flag is explicitly added. This allows binaries compiled on systems which do not support the rdseed instruction to use the instruction if the execution platform supports it. At run-time on x86, __rte_random_initial_seed() will check for the availability of the rdseed instruction on the execution platform using rte_cpu_get_flag_enabled(). This allows binaries which were compiled on systems which support the rdseed instruction to run on x86 CPUs which do not support the rdseed instruction. RTE_CPUFLAG_RDSEED is removed from the list of RTE_COMPILE_TIME_CPUFLAGS which are checked in rte_eal_init() at run time because it is no longer required to match the compilation system. Signed-off-by: Dan Gora --- config/x86/meson.build | 11 ++++++++--- lib/librte_eal/common/rte_random.c | 19 +++++++++++-------- mk/rte.cpuflags.mk | 9 +++++++-- 3 files changed, 26 insertions(+), 13 deletions(-) diff --git a/config/x86/meson.build b/config/x86/meson.build index adc857ba2..9491fad3a 100644 --- a/config/x86/meson.build +++ b/config/x86/meson.build @@ -20,15 +20,20 @@ if cc.get_define('__SSE4_2__', args: machine_args) == '' machine_args += '-msse4' endif +# set -mrdseed if necessary so _rdseed32_step compiles if the +# compilation host does not support the RDSEED instruction. +if cc.get_define('__RDSEED__', args: machine_args) == '' and cc.has_argument('-mrdseed') + machine_args += '-mrdseed' + message('RDSEED not enabled by default, explicitly setting -mrdseed') +endif + base_flags = ['SSE', 'SSE2', 'SSE3','SSSE3', 'SSE4_1', 'SSE4_2'] foreach f:base_flags dpdk_conf.set('RTE_MACHINE_CPUFLAG_' + f, 1) compile_time_cpuflags += ['RTE_CPUFLAG_' + f] endforeach -optional_flags = ['AES', 'PCLMUL', - 'AVX', 'AVX2', 'AVX512F', - 'RDRND', 'RDSEED'] +optional_flags = ['AES', 'PCLMUL', 'AVX', 'AVX2', 'AVX512F', 'RDRND'] foreach f:optional_flags if cc.get_define('__@0@__'.format(f), args: machine_args) == '1' if f == 'PCLMUL' # special case flags with different defines diff --git a/lib/librte_eal/common/rte_random.c b/lib/librte_eal/common/rte_random.c index b7a089ac4..2c84c8527 100644 --- a/lib/librte_eal/common/rte_random.c +++ b/lib/librte_eal/common/rte_random.c @@ -2,7 +2,7 @@ * Copyright(c) 2019 Ericsson AB */ -#ifdef RTE_MACHINE_CPUFLAG_RDSEED +#if defined(RTE_ARCH_X86) #include #endif #include @@ -188,14 +188,17 @@ __rte_random_initial_seed(void) if (ge_rc == 0) return ge_seed; #endif -#ifdef RTE_MACHINE_CPUFLAG_RDSEED - unsigned int rdseed_low; - unsigned int rdseed_high; - +#if defined(RTE_ARCH_X86) /* first fallback: rdseed instruction, if available */ - if (_rdseed32_step(&rdseed_low) == 1 && - _rdseed32_step(&rdseed_high) == 1) - return (uint64_t)rdseed_low | ((uint64_t)rdseed_high << 32); + if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_RDSEED)) { + unsigned int rdseed_low; + unsigned int rdseed_high; + + if (_rdseed32_step(&rdseed_low) == 1 && + _rdseed32_step(&rdseed_high) == 1) + return (uint64_t)rdseed_low | + ((uint64_t)rdseed_high << 32); + } #endif /* second fallback: seed using rdtsc */ return rte_get_tsc_cycles(); diff --git a/mk/rte.cpuflags.mk b/mk/rte.cpuflags.mk index fa8753531..a114e9c02 100644 --- a/mk/rte.cpuflags.mk +++ b/mk/rte.cpuflags.mk @@ -51,8 +51,13 @@ ifneq ($(filter $(AUTO_CPUFLAGS),__RDRND__),) CPUFLAGS += RDRAND endif -ifneq ($(filter $(AUTO_CPUFLAGS),__RDSEED__),) -CPUFLAGS += RDSEED +ifeq ($(filter $(AUTO_CPUFLAGS),__RDSEED__),) +# If the native environment doesn't define __RDSEED__, see +# if the compiler supports -mrdseed. +RDSEED_CPUFLAGS := $(shell $(CC) $(MACHINE_CFLAGS) $(WERROR_FLAGS) $(EXTRA_CFLAGS) -mrdseed -dM -E - < /dev/null) +ifneq ($(filter $(RDSEED_CPUFLAGS),__RDSEED__),) +MACHINE_CFLAGS += -mrdseed +endif endif ifneq ($(filter $(AUTO_CPUFLAGS),__FSGSBASE__),) -- 2.24.1.425.g7034cd094b