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=-0.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 04BFDC48BD7 for ; Thu, 27 Jun 2019 15:38:49 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id CC6C320656 for ; Thu, 27 Jun 2019 15:38:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="le+R9R8o" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CC6C320656 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1hgWTm-0005mk-G6; Thu, 27 Jun 2019 15:38:30 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1hgWTl-0005mf-Ll for xen-devel@lists.xenproject.org; Thu, 27 Jun 2019 15:38:29 +0000 X-Inumbo-ID: 9c3f1166-98f1-11e9-be4f-735414ef5475 Received: from mail.kernel.org (unknown [198.145.29.99]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 9c3f1166-98f1-11e9-be4f-735414ef5475; Thu, 27 Jun 2019 15:38:29 +0000 (UTC) Received: from localhost (c-67-164-102-47.hsd1.ca.comcast.net [67.164.102.47]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 15F7220656; Thu, 27 Jun 2019 15:38:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1561649908; bh=y/gAZTbbnke/lqh7QdUGuOmflgUksCdsNFUi5p1cn+Y=; h=Date:From:To:cc:Subject:In-Reply-To:References:From; b=le+R9R8oHbhupeZ84H9WlAWk1VY5u3vTXAuYChJqK8ibHz2nIfFizf0NV2mVl4Gl8 nm4Se7Tx/6oFtvdVm+4oPdMlc6AtKvMbLe+qOUr/0Ap1nHwiQ5tl3AvbSBJ9bxbGDz QsFxvxZb1/tvFFO9wCHUmC3YR6P0YNZcwGcmn0YI= Date: Thu, 27 Jun 2019 08:38:27 -0700 (PDT) From: Stefano Stabellini X-X-Sender: sstabellini@sstabellini-ThinkPad-T480s To: Julien Grall In-Reply-To: <4d2fc214-4e8c-6c40-68ec-c35b6f9e5dab@arm.com> Message-ID: References: <20190610193215.23704-1-julien.grall@arm.com> <20190610193215.23704-16-julien.grall@arm.com> <218cf497-cbb5-7213-7678-6294ac3e0882@arm.com> <4d2fc214-4e8c-6c40-68ec-c35b6f9e5dab@arm.com> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="8323329-1252697341-1561649908=:5851" Subject: Re: [Xen-devel] [PATCH 15/17] xen/arm64: head: Rework and document setup_fixmap() X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: xen-devel@lists.xenproject.org, Oleksandr_Tyshchenko@epam.com, Stefano Stabellini , andrii_anisov@epam.com, andre.przywara@arm.com Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --8323329-1252697341-1561649908=:5851 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT On Thu, 27 Jun 2019, Julien Grall wrote: > Hi Stefano, > > On 26/06/2019 20:30, Julien Grall wrote: > > On 6/26/19 8:01 PM, Stefano Stabellini wrote: > > > On Mon, 10 Jun 2019, Julien Grall wrote: > > > > At the moment, the fixmap table is only hooked when earlyprintk is used. > > > > This is fine today because in C land, the fixmap is not used by anyone > > > > until the the boot CPU is switching to the runtime page-tables. > > > > > > > > In the future, the boot CPU will not switch between page-tables to avoid > > > > TLB conflict. This means the fixmap table will need to be hooked before > > > > any use. For simplicity, setup_fixmap() will now do that job. > > > > > > Can I ask you to reword this slightly, especially the last sentence? It > > > took me a while to understand what you meant. I suggest: > > > > > >   In the future, the boot CPU will not switch between page-tables to > > >   avoid any TLB conflicts. Thus, the fixmap table will need to be always > > >   hooked before any use. Let's start doing it now in setup_fixmap(). > > > > > > > I will update the commit message. > > I realized the commit message I wrote is inaccurate and reflected to your > rewording. > > Not all the platforms will generate a TLB conflict abort. Some of them may > just decide to use an amalgamation of two entries (see "TLB matching" page > D5-2500 in ARM DDI 0487D.b). > > I will replace "any TLB conflicts" by "TLB incoherency". > > > > > > Acked-by: Stefano Stabellini > > > Let me know if you are happy with the change suggested. Yes, that's fine --8323329-1252697341-1561649908=:5851 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Content-Disposition: inline X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KWGVuLWRldmVs IG1haWxpbmcgbGlzdApYZW4tZGV2ZWxAbGlzdHMueGVucHJvamVjdC5vcmcKaHR0cHM6Ly9saXN0 cy54ZW5wcm9qZWN0Lm9yZy9tYWlsbWFuL2xpc3RpbmZvL3hlbi1kZXZlbA== --8323329-1252697341-1561649908=:5851--