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 6CD19C433F5 for ; Tue, 1 Feb 2022 19:02:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232052AbiBATCY (ORCPT ); Tue, 1 Feb 2022 14:02:24 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32912 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229565AbiBATCW (ORCPT ); Tue, 1 Feb 2022 14:02:22 -0500 Received: from mail.skyhub.de (mail.skyhub.de [IPv6:2a01:4f8:190:11c2::b:1457]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4CD97C061714 for ; Tue, 1 Feb 2022 11:02:22 -0800 (PST) Received: from zn.tnic (dslb-088-067-221-104.088.067.pools.vodafone-ip.de [88.67.221.104]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id B12341EC0453; Tue, 1 Feb 2022 20:02:16 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1643742136; 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: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=sMD/D31sXs4fBGWeHEfOilbAUNlN6E+BckKU637Cks8=; b=MkLQo87j6k+qoMo5XV7fJI1jxPFle1fNlSyXro2g1sNO/bGu8oUCgjQWt8Lz9c0MLke0Ww dv5kNMRdFBcQUAH9qgCmj2KkqOS7IC1ovOUmiddqrb8+Q4O6ex1BWY46NCjzgXgQKr3jE9 9hH8B1yCNUvTkYvRDTwOTEcir6/PwNw= Date: Tue, 1 Feb 2022 20:02:12 +0100 From: Borislav Petkov To: "Kirill A. Shutemov" Cc: tglx@linutronix.de, mingo@redhat.com, dave.hansen@intel.com, luto@kernel.org, peterz@infradead.org, sathyanarayanan.kuppuswamy@linux.intel.com, aarcange@redhat.com, ak@linux.intel.com, dan.j.williams@intel.com, david@redhat.com, hpa@zytor.com, jgross@suse.com, jmattson@google.com, joro@8bytes.org, jpoimboe@redhat.com, knsathya@kernel.org, pbonzini@redhat.com, sdeep@vmware.com, seanjc@google.com, tony.luck@intel.com, vkuznets@redhat.com, wanpengli@tencent.com, x86@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCHv2 11/29] x86/boot: Allow to hook up alternative port I/O helpers Message-ID: References: <20220124150215.36893-1-kirill.shutemov@linux.intel.com> <20220124150215.36893-12-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20220124150215.36893-12-kirill.shutemov@linux.intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 24, 2022 at 06:01:57PM +0300, Kirill A. Shutemov wrote: > Port I/O instructions trigger #VE in the TDX environment. In response to > the exception, kernel emulates these instructions using hypercalls. > > But during early boot, on the decompression stage, it is cumbersome to > deal with #VE. It is cleaner to go to hypercalls directly, bypassing #VE > handling. > > Add a way to hook up alternative port I/O helpers in the boot stub. > All port I/O operations are routed via 'pio_ops'. By default 'pio_ops' > initialized with native port I/O implementations. I see that you like to talk about what a patch is doing in the commit message but there's really no need for it - that's visible from the diff itself, hopefully. So talk about the *why* instead, pls. > This is a preparation patch. The next patch will override 'pio_ops' if > the kernel booted in the TDX environment. That's also not needed. The rest LGTM. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette