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=-5.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 4E3D6C433DF for ; Fri, 29 May 2020 09:02:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1CE3C208A7 for ; Fri, 29 May 2020 09:02:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="PvGwZ3rY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726549AbgE2JCa (ORCPT ); Fri, 29 May 2020 05:02:30 -0400 Received: from mail.skyhub.de ([5.9.137.197]:44990 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725601AbgE2JC3 (ORCPT ); Fri, 29 May 2020 05:02:29 -0400 Received: from zn.tnic (p200300ec2f0f5e00e15a1b2e1d2ace20.dip0.t-ipconnect.de [IPv6:2003:ec:2f0f:5e00:e15a:1b2e:1d2a:ce20]) (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 35F751EC03D2; Fri, 29 May 2020 11:02:28 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1590742948; 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=YgI+deux/7QqPwTMEpnAWUAEJvChvf4UJKUuseczbb4=; b=PvGwZ3rYkyScKSVfHSnOMSijlVOIzSrLpHiSrsUElDG4vAzwAYEsx6De23tXnYVphT6ZgT Dr4h4i5vlcTx2lq79mmX7QhWu+2bY+eytnB7asc3JQXZjR8YwcsapWBxZvRxBUX7Wwrh7X U2INYoyOAHuXtTHPwVuZtStgsNeMBEs= Date: Fri, 29 May 2020 11:02:22 +0200 From: Borislav Petkov To: Joerg Roedel Cc: x86@kernel.org, hpa@zytor.com, Andy Lutomirski , Dave Hansen , Peter Zijlstra , Jiri Slaby , Dan Williams , Tom Lendacky , Juergen Gross , Kees Cook , David Rientjes , Cfir Cohen , Erdem Aktas , Masami Hiramatsu , Mike Stunes , Joerg Roedel , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org Subject: Re: [PATCH v3 69/75] x86/realmode: Setup AP jump table Message-ID: <20200529090222.GA9011@zn.tnic> References: <20200428151725.31091-1-joro@8bytes.org> <20200428151725.31091-70-joro@8bytes.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20200428151725.31091-70-joro@8bytes.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 28, 2020 at 05:17:19PM +0200, Joerg Roedel wrote: > From: Tom Lendacky > > Setup the AP jump table to point to the SEV-ES trampoline code so that > the APs can boot. Tom, in his laconic way, doesn't want to explain to us why is this even needed... :) /me reads the code /me reads the GHCB spec aha, it gets it from the HV. And it can be set by the guest too... So how about expanding that commit message as to why this is done, why needed, etc? Thx. > diff --git a/arch/x86/realmode/init.c b/arch/x86/realmode/init.c > index 262f83cad355..1c5cbfd102d5 100644 > --- a/arch/x86/realmode/init.c > +++ b/arch/x86/realmode/init.c > @@ -9,6 +9,7 @@ > #include > #include > #include > +#include > > struct real_mode_header *real_mode_header; > u32 *trampoline_cr4_features; > @@ -107,6 +108,11 @@ static void __init setup_real_mode(void) > if (sme_active()) > trampoline_header->flags |= TH_FLAGS_SME_ACTIVE; > > + if (sev_es_active()) { > + if (sev_es_setup_ap_jump_table(real_mode_header)) > + panic("Failed to update SEV-ES AP Jump Table"); > + } > + So this function gets slowly sprinkled with if (sev-something) bla Please wrap at least those last two into a sev_setup_real_mode() or so. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette