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 0E5B2C433EF for ; Tue, 1 Feb 2022 18:31:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237603AbiBASbD (ORCPT ); Tue, 1 Feb 2022 13:31:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53478 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234686AbiBASbC (ORCPT ); Tue, 1 Feb 2022 13:31:02 -0500 Received: from mail.skyhub.de (mail.skyhub.de [IPv6:2a01:4f8:190:11c2::b:1457]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ED3B7C061714 for ; Tue, 1 Feb 2022 10:31:01 -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 60A7C1EC0513; Tue, 1 Feb 2022 19:30:56 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1643740256; 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=SelJnsO3AI+ddNI4mpxmGVzS4kYycs/voWIlYXQsR6c=; b=MkB9SXbeyDNgeqM0WeSGqg8Xv9ksewonLwTSCjuAT5FuM8zjbys8kwBL+IIQwoAk44NsWg Re0J289D0PTENYTO30XUnlqrGmsJKvZKNkibHmOtxLaOwvIFVuOPMxRMqbnPZQtDCdqALD CTWsRxSY0ELzQVIfT1Hs6Bu1jmcV7Pk= Date: Tue, 1 Feb 2022 19:30:52 +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 09/29] x86/tdx: Detect TDX at early kernel decompression time Message-ID: References: <20220124150215.36893-1-kirill.shutemov@linux.intel.com> <20220124150215.36893-10-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20220124150215.36893-10-kirill.shutemov@linux.intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 24, 2022 at 06:01:55PM +0300, Kirill A. Shutemov wrote: > From: Kuppuswamy Sathyanarayanan > > The early decompression code does port I/O for its console output. But, > handling the decompression-time port I/O demands a different approach > from normal runtime because the IDT required to support #VE based port > I/O emulation is not yet set up. Paravirtualizing I/O calls during > the decompression step is acceptable because the decompression code size is > small enough and hence patching it will not bloat the image size a lot. > > To support port I/O in decompression code, TDX must be detected before > the decompression code might do port I/O. Add support to detect for > TDX guest support before console_init() in the extract_kernel(). s/Add support to detect for TDX guest support before console_init() in the extract_kernel()./Detect whether the kernel runs in a TDX guest./ Simple. > Detecting it above the console_init() is early enough for patching > port I/O. No need for that sentence - there's already a comment above the call below. > > Add an early_is_tdx_guest() interface to get the cached TDX guest s/get/query/ > status in the decompression code. ... > diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c > index a4339cb2d247..d8373d766672 100644 > --- a/arch/x86/boot/compressed/misc.c > +++ b/arch/x86/boot/compressed/misc.c > @@ -370,6 +370,14 @@ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap, > lines = boot_params->screen_info.orig_video_lines; > cols = boot_params->screen_info.orig_video_cols; > > + /* > + * Detect TDX guest environment. > + * > + * It has to be done before console_init() in order to use > + * paravirtualized port I/O oprations if needed. Unknown word [oprations] in comment. Suggestions: ['orations', 'operations', 'op rations', 'op-rations', 'preparations', 'reparations', 'inspirations', 'operation'] > + */ > + early_tdx_detect(); > + > console_init(); > > /* ... > diff --git a/arch/x86/include/asm/shared/tdx.h b/arch/x86/include/asm/shared/tdx.h > new file mode 100644 > index 000000000000..12bede46d048 > --- /dev/null > +++ b/arch/x86/include/asm/shared/tdx.h > @@ -0,0 +1,7 @@ > +#ifndef _ASM_X86_SHARED_TDX_H > +#define _ASM_X86_SHARED_TDX_H WARNING: Missing or malformed SPDX-License-Identifier tag in line 1 #232: FILE: arch/x86/include/asm/shared/tdx.h:1: +#ifndef _ASM_X86_SHARED_TDX_H Why isn't checkpatch part of your patch creation workflow? > + > +#define TDX_CPUID_LEAF_ID 0x21 > +#define TDX_IDENT "IntelTDX " > + > +#endif ^ /* _ASM_X86_SHARED_TDX_H */ -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette