From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5EE56ECAAD5 for ; Tue, 30 Aug 2022 21:43:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231704AbiH3Vnw (ORCPT ); Tue, 30 Aug 2022 17:43:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45354 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231683AbiH3Vnl (ORCPT ); Tue, 30 Aug 2022 17:43:41 -0400 Received: from mail-pl1-x62b.google.com (mail-pl1-x62b.google.com [IPv6:2607:f8b0:4864:20::62b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2D1938C446 for ; Tue, 30 Aug 2022 14:43:33 -0700 (PDT) Received: by mail-pl1-x62b.google.com with SMTP id c2so12376574plo.3 for ; Tue, 30 Aug 2022 14:43:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc; bh=yxuPGAgyr2YjlkXSwoWeZko/CUmlXgmDG76kUE3q7zA=; b=aH4Waxy1Ly1CTXiseORnUequMFv5g4WKFXKSK01Tg3E5FoZ7Voi3A6YVqRdS/Dd0Yl 1IoVc+nowFtPr5sPbdRIHZ1iyG9u4lJTSJyCUmSP0X7QPDn3TFtRJYxHIeF3+PHo083R QBmouR14BZZWovfe7pvOcUGHQWH546mpL+nAEYCtDfZjacoRQiIDC7mlRqp0vVxvWbG7 QNG0bk3KcvENRkbms8yzQC87X4mXCIxqcG9eNc8FQ43O7QkXjA43sNzxIXJ5HI8HjdL/ ciJz06EE+gFPjAaYrwoEe1da4NDUZ9u5CAwUolpEhve8fC45OLNAdyfxeU4E3Gyyxus2 pZcQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc; bh=yxuPGAgyr2YjlkXSwoWeZko/CUmlXgmDG76kUE3q7zA=; b=gvJeZ+5Ab6d7b4nkn/IclonlzJXo8Vg7oZmCaY+9bYEdFa7Ciy9UNLywxyE83i5z6c 7MOVGR3wrADjcbY46yzcTsLbZmUt9TbbyqC0uQGpvIjD7i600SwjRijum/Zqx+UxlNWj itOuL07uoxyITrHzOdlYBVIlgcvI8nAKoD3jBwEJqTF4tCBZs5hAjuMvfY9Wp0b1S1HW McEua/eTuSwoQwjUjFluhh4tltPNfsACkYguV1J96Yy28oOXllevprZTNFUBJrHaqpFR ZZdCLhJ7RZ9MlezHgxIV8b4wXfQwg3uVF3hs0YGnE/M1UWDewuRNh6OniM8njocOkwvR xtZg== X-Gm-Message-State: ACgBeo0IgkLUCgQhmAO4Uol7XrMMzuLhjoc5CBXagKS+YFsWHWa69x6N CWRKZVjUp5634MrM72kTGEwsSYES2XNkbQ== X-Google-Smtp-Source: AA6agR4d9a86XOYmekbqcUomIz+HR7ZC0q/6LOY3PB+81Acv7okg/KHbPM8scoZKhlG1pAM+Wzz7Eg== X-Received: by 2002:a17:902:edd5:b0:174:a6e6:51f4 with SMTP id q21-20020a170902edd500b00174a6e651f4mr13206714plk.82.1661895812536; Tue, 30 Aug 2022 14:43:32 -0700 (PDT) Received: from google.com (7.104.168.34.bc.googleusercontent.com. [34.168.104.7]) by smtp.gmail.com with ESMTPSA id j8-20020a170903024800b00172e97382cdsm10404872plh.285.2022.08.30.14.43.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 30 Aug 2022 14:43:32 -0700 (PDT) Date: Tue, 30 Aug 2022 21:43:28 +0000 From: Sean Christopherson To: Uros Bizjak Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Paolo Bonzini Subject: Re: [PATCH] KVM/VMX: Avoid stack engine synchronization uop in __vmx_vcpu_run Message-ID: References: <20220816211010.25693-1-ubizjak@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220816211010.25693-1-ubizjak@gmail.com> Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Tue, Aug 16, 2022, Uros Bizjak wrote: > Avoid instructions with explicit uses of the stack pointer between > instructions that implicitly refer to it. The sequence of > POP %reg; ADD $x, %RSP; POP %reg forces emission of synchronization > uop to synchronize the value of the stack pointer in the stack engine > and the out-of-order core. > > Using POP with the dummy register instead of ADD $x, %RSP results in a > smaller code size and faster code. > > The patch also fixes the reference to the wrong register in the > nearby comment. > > Cc: Paolo Bonzini > Cc: Sean Christopherson > Signed-off-by: Uros Bizjak > --- Pushed to branch `for_paolo/6.1` at: https://github.com/sean-jc/linux.git Unless you hear otherwise, it will make its way to kvm/queue "soon". Note, the commit IDs are not guaranteed to be stable.