From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: ARC-Seal: i=1; a=rsa-sha256; t=1517026844; cv=none; d=google.com; s=arc-20160816; b=fKc5nd1x7lnb9iqEPFuhj3vVYTuWOIUIHl46g/VFmf7tWhz4PBvT3tESsP1hSW3DNx viHOa7J8E2n5RWtNYlShqeF4bQlO1Q8MSp2UhYDIei9alvzMUBeUSHYSpljfLvZFgoxf Vr4svykF+pEaY2WZkFooL2VyL35Z2rNRdB4PuYh/7ECR1RkmfuLmdhoIyyQ0OALLSTH9 01kYK5JrLTZzQSDusF+wIwA90a4YgVIn7SXU/OTiN7/oNchq7K0NmbfmPwHIQ/zQ+SWX UJu/KHJOYJ9EXGrbwuW0OhHRqNPZeVbMrKO7i6CvRuepkNhenzpdGZaDzsapZYyZc79u ApnQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=user-agent:in-reply-to:content-transfer-encoding :content-disposition:mime-version:references:message-id:subject:cc :to:from:date:sender:dkim-signature:arc-authentication-results; bh=KJlFggUXyWVIb85VcDfxlzz+3UcwyyLdCL9J/GPP6Qw=; b=K09RPquwbDM+zzsOMpKVmVkfmvX13mvbgthpx1DXDyisTzUGInUnf/fcvImHgumkkO g/ACfeMccS1ad+XciGrq+LnL0AIlkhjZydkYZ2We/1hrC+OEqB7oAp9d4mMSsaLDfvhm L13EotwvJSuLyfBAootp+4+hkDV2weCSS9JeN9lmiRyrUWVyu6H8MsXm+p2MfpGkWaqq isFdS3g7NQf6hQuVqXZYYcvmiuCT+1+cdXorOcsU0TMV/MxDYcMWrxrgg9fzYbhmW8Mq FCcns8O6Lc+GfijsRHEmRCPatR8RutQIrdhoZh2TGjHScTDNng8nLF7E+Xaqwhw9D+ZK MIMw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=pVbUIcJ+; spf=pass (google.com: domain of konrad.r.wilk@gmail.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=konrad.r.wilk@gmail.com Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=pVbUIcJ+; spf=pass (google.com: domain of konrad.r.wilk@gmail.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=konrad.r.wilk@gmail.com X-Google-Smtp-Source: AH8x225dhfrHvCx2dBudhgORCknC8DvCVkF8SUc/CcVP9QzcY0bcazLZoONl31X/5mgXCWa7i61GYg== Sender: Konrad Rzeszutek Wilk Date: Fri, 26 Jan 2018 23:20:39 -0500 From: Konrad Rzeszutek Wilk To: Borislav Petkov Cc: David Woodhouse , X86 ML , LKML , Josh Poimboeuf , tim.c.chen@linux.intel.com, pjt@google.com, jikos@kernel.org, gregkh@linux-foundation.org, dave.hansen@intel.com, riel@redhat.com, luto@amacapital.net, torvalds@linux-foundation.org, ak@linux.intel.com, keescook@google.com, peterz@infradead.org Subject: Re: [PATCH v2 1/2] x86/retpoline: Simplify vmexit_fill_RSB() Message-ID: <20180127042035.GA21508@localhost.localdomain> References: <20180126121139.31959-1-bp@alien8.de> <20180126121139.31959-4-bp@alien8.de> <1516970011.30244.223.camel@infradead.org> <20180126132431.fsbd3c3g2yreazy6@pd.tnic> <1516983879.30244.236.camel@infradead.org> <20180126164746.dpo7dswid5tjk2tz@pd.tnic> <20180126200616.5xfn244uzeu7ptyo@pd.tnic> <20180126200725.rueqb2m6b4w47eu3@pd.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20180126200725.rueqb2m6b4w47eu3@pd.tnic> User-Agent: Mutt/1.9.1 (2017-09-22) X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1590656989548468968?= X-GMAIL-MSGID: =?utf-8?q?1590717940144071903?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: > + * Google experimented with loop-unrolling and this turned out to be > + * the optimal version — two calls, each with their own speculation > + * trap should their return address end up getting used, in a loop. > + */ > +.macro BOINK_RSB nr:req sp:req BOINK? Really?