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 08DA5C433EF for ; Wed, 22 Dec 2021 13:16:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240878AbhLVNQo (ORCPT ); Wed, 22 Dec 2021 08:16:44 -0500 Received: from mail.skyhub.de ([5.9.137.197]:37512 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236982AbhLVNQo (ORCPT ); Wed, 22 Dec 2021 08:16:44 -0500 Received: from zn.tnic (dslb-088-067-202-008.088.067.pools.vodafone-ip.de [88.67.202.8]) (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 16E271EC053B; Wed, 22 Dec 2021 14:16:38 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1640178998; 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=ldBbr5F47BRkNwI3KCFQS/UodY8GZ2FSKRo/NdAeHoA=; b=e69K3Rot7r+DAZgXj9o0t3pGLM4ORQDocgHgt/iL0f+XvQ11GV/SzjuIH9Zjvnw9lvaLp4 fmyEq6Rixyg4hGNaZ1bl0Tcga3404uXxPkVRnzjAke6Q6llvGHEkMlJBlaYa+JCKI+w0dv 9a0WJ1k2HOZsvuXUs5ZjYmGdvr7X/zs= Date: Wed, 22 Dec 2021 14:16:40 +0100 From: Borislav Petkov To: Brijesh Singh Cc: x86@kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-efi@vger.kernel.org, platform-driver-x86@vger.kernel.org, linux-coco@lists.linux.dev, linux-mm@kvack.org, Thomas Gleixner , Ingo Molnar , Joerg Roedel , Tom Lendacky , "H. Peter Anvin" , Ard Biesheuvel , Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Jim Mattson , Andy Lutomirski , Dave Hansen , Sergio Lopez , Peter Gonda , Peter Zijlstra , Srinivas Pandruvada , David Rientjes , Dov Murik , Tobin Feldman-Fitzthum , Michael Roth , Vlastimil Babka , "Kirill A . Shutemov" , Andi Kleen , "Dr . David Alan Gilbert" , tony.luck@intel.com, marcorr@google.com, sathyanarayanan.kuppuswamy@linux.intel.com Subject: Re: [PATCH v8 11/40] x86/sev: Register GHCB memory when SEV-SNP is active Message-ID: References: <20211210154332.11526-1-brijesh.singh@amd.com> <20211210154332.11526-12-brijesh.singh@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20211210154332.11526-12-brijesh.singh@amd.com> Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Fri, Dec 10, 2021 at 09:43:03AM -0600, Brijesh Singh wrote: > @@ -652,7 +652,7 @@ static enum es_result vc_handle_msr(struct ghcb *ghcb, struct es_em_ctxt *ctxt) > * This function runs on the first #VC exception after the kernel > * switched to virtual addresses. > */ > -static bool __init sev_es_setup_ghcb(void) > +static bool __init setup_ghcb(void) > { > /* First make sure the hypervisor talks a supported protocol. */ > if (!sev_es_negotiate_protocol()) Ok, let me stare at this for a while: This gets called by handle_vc_boot_ghcb() which gets set at build time: arch/x86/kernel/head_64.S:372:SYM_DATA(initial_vc_handler, .quad handle_vc_boot_ghcb) initial_vc_handler() gets called by vc_boot_ghcb() which gets set in early_setup_idt() and that function already does sev_snp_register_ghcb(). So why don't you concentrate the work setup_ghcb() does before the first #VC and call it in early_setup_idt(), before the IDT is set? And then you get rid of yet another setup-at-first-use case? Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette