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 X-Spam-Level: X-Spam-Status: No, score=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9F03BC38A2A for ; Sat, 9 May 2020 00:15:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7BDB5208CA for ; Sat, 9 May 2020 00:15:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588983304; bh=04iNIHT/D+y8mL2H3VwMuWm5RnWhaS/X1x6j6jldBNQ=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=GPBwwJ4DvxlMY+5ljwKllDYI1Q7e1qUEW9wVm+usmByy2s68T2q+PWLNxO/RHscWF MYQkkFFSIxf2pzsUc888xDh5T8qgy6u6GDbs9xzMXDc96t0J2rcElRgM3yyi4sz+mN bIhzsSu0JpmJTa6IOsgIFLcEJkO9RElyRCpuzJEo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728426AbgEIAPD (ORCPT ); Fri, 8 May 2020 20:15:03 -0400 Received: from mail.kernel.org ([198.145.29.99]:38752 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727983AbgEIAPC (ORCPT ); Fri, 8 May 2020 20:15:02 -0400 Received: from mail-wr1-f41.google.com (mail-wr1-f41.google.com [209.85.221.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 07C992496A for ; Sat, 9 May 2020 00:15:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588983302; bh=04iNIHT/D+y8mL2H3VwMuWm5RnWhaS/X1x6j6jldBNQ=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=fnfXFe7TSB/8SepidulViTVdYAdldUWn08mBQGu9C1BQQOvQlk/l6DjtzjSOdDQbr S+5OVEgEQuNthe09wovg0PV+3yASAiif0l2FdtyduqG97JKFVRELMqxji+IMMLnWDV ptUkodlPS3YV1TCGtp8Ecl9r4MAClWCGrcX579z8= Received: by mail-wr1-f41.google.com with SMTP id h9so3914514wrt.0 for ; Fri, 08 May 2020 17:15:01 -0700 (PDT) X-Gm-Message-State: AGi0PuZ1KboD6NWuIDjhVwreDXwYtqfv2DmHMtX2QZMbfCw3VTK02n2E oF3vdQXNLYuz8/IJ1O/+PrRLNeWb1nofh/mLwNnJ/A== X-Google-Smtp-Source: APiQypKmaMXaSt8iEKR+x00GxdW48hFznd/utZShjM6SrX0pPnGKp7nJpnxjsfEcADAWlK4toqijvCfzMgXH66DbBFI= X-Received: by 2002:adf:fe45:: with SMTP id m5mr5542385wrs.257.1588983300442; Fri, 08 May 2020 17:15:00 -0700 (PDT) MIME-Version: 1.0 References: <20200505134112.272268764@linutronix.de> <20200505134341.379326289@linutronix.de> In-Reply-To: <20200505134341.379326289@linutronix.de> From: Andy Lutomirski Date: Fri, 8 May 2020 17:14:49 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [patch V4 part 2 13/18] x86/kvm: Move context tracking where it belongs To: Thomas Gleixner Cc: LKML , X86 ML , "Paul E. McKenney" , Andy Lutomirski , Alexandre Chartre , Frederic Weisbecker , Paolo Bonzini , Sean Christopherson , Masami Hiramatsu , Petr Mladek , Steven Rostedt , Joel Fernandes , Boris Ostrovsky , Juergen Gross , Brian Gerst , Mathieu Desnoyers , Josh Poimboeuf , Will Deacon Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 5, 2020 at 7:14 AM Thomas Gleixner wrote: > > Context tracking for KVM happens way too early in the vcpu_run() > code. Anything after guest_enter_irqoff() and before guest_exit_irqoff() > cannot use RCU and should also be not instrumented. > > The current way of doing this covers way too much code. Move it closer to > the actual vmenter/exit code. Now you've made me wonder what happens if someone traces vmx_vcpu_run(). I'm not sure I really want to think about this.