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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 770ECC433F5 for ; Thu, 25 Nov 2021 11:19:55 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D7DF86B0074; Thu, 25 Nov 2021 06:19:39 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id D2D356B0075; Thu, 25 Nov 2021 06:19:39 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C1CB66B007B; Thu, 25 Nov 2021 06:19:39 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0247.hostedemail.com [216.40.44.247]) by kanga.kvack.org (Postfix) with ESMTP id B01456B0074 for ; Thu, 25 Nov 2021 06:19:39 -0500 (EST) Received: from smtpin05.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 6F47718090175 for ; Thu, 25 Nov 2021 11:19:29 +0000 (UTC) X-FDA: 78847207110.05.7454151 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by imf27.hostedemail.com (Postfix) with ESMTP id 9AE4D700009D for ; Thu, 25 Nov 2021 11:19:27 +0000 (UTC) From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1637839167; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=/ma5VbatWNFQZCLFlfHQQnL8bQbyHFoYfeKADC16NCw=; b=4ePzyve3BV8W3Ri0w2FAt94m/sR5E2beQ9Uzi+snKcGE1+C9sSemwZdCWvyOdNjoJOG9tc L5/g99loi2VqkMdpDQ8IdFbluX4ZM/ugzVUhvMjE+QintyM0hWvSUlxwGrs5/Q05fS6YDR nWcKWslu0wvP6/Cq/wEe9IFSOxVCcWbvmx1OGDMH/1z4nbz84KP/gysD5enVRBaLP2pffu 1KO/uSL7KpyKmJD7meAq9RdoU1eBZ5WQoQ2LLsOYyEcesTjMHz7lG3A9C6rc1d7FFvIJGv mdp+iWt3SkrHeBODGzbJqr5fFflFFFYW8wIEr6ltneHooGZQd02seIViPWBCMg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1637839167; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=/ma5VbatWNFQZCLFlfHQQnL8bQbyHFoYfeKADC16NCw=; b=NXTbV8DDLwaeOj+cBZrvOlV2D4CmfDV75T/cGw6iKtVmqnEoQEAFdJ/LixPiuBWQtghkmD +xPVaQ4L7mjRytCw== To: Ira Weiny , Dave Hansen , Dan Williams , Andy Lutomirski , "H. Peter Anvin" Cc: Peter Zijlstra , Ingo Molnar , Borislav Petkov , Fenghua Yu , Rick Edgecombe , x86@kernel.org, linux-kernel@vger.kernel.org, nvdimm@lists.linux.dev, linux-mm@kvack.org Subject: Re: [PATCH V7 08/18] x86/entry: Preserve PKRS MSR across exceptions In-Reply-To: <20211113005051.GN3538886@iweiny-DESK2.sc.intel.com> References: <20210804043231.2655537-1-ira.weiny@intel.com> <20210804043231.2655537-9-ira.weiny@intel.com> <20211113005051.GN3538886@iweiny-DESK2.sc.intel.com> Date: Thu, 25 Nov 2021 12:19:26 +0100 Message-ID: <8735nkmqip.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain X-Stat-Signature: wdumz11xg1ku8daijbfrzouy8e59hws6 Authentication-Results: imf27.hostedemail.com; dkim=pass header.d=linutronix.de header.s=2020 header.b=4ePzyve3; dkim=pass header.d=linutronix.de header.s=2020e header.b=NXTbV8DD; dmarc=pass (policy=none) header.from=linutronix.de; spf=pass (imf27.hostedemail.com: domain of tglx@linutronix.de designates 193.142.43.55 as permitted sender) smtp.mailfrom=tglx@linutronix.de X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 9AE4D700009D X-HE-Tag: 1637839167-850426 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, Nov 12 2021 at 16:50, Ira Weiny wrote: > On Tue, Aug 03, 2021 at 09:32:21PM -0700, 'Ira Weiny' wrote: >> From: Ira Weiny >> >> The PKRS MSR is not managed by XSAVE. It is preserved through a context >> switch but this support leaves exception handling code open to memory >> accesses during exceptions. >> >> 2 possible places for preserving this state were considered, >> irqentry_state_t or pt_regs.[1] pt_regs was much more complicated and >> was potentially fraught with unintended consequences.[2] However, Andy >> came up with a way to hide additional values on the stack which could be >> accessed as "extended_pt_regs".[3] > > Andy, > > I'm preparing to send V8 of this PKS work. But I have not seen any feed back > since I originally implemented this in V4[1]. > > Does this meets your expectations? Are there any issues you can see with this > code? > > I would appreciate your feedback. Not Andy here, but I'll respond to the patch in a minute. Thanks, tglx