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=-13.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 A5AA3C433E8 for ; Fri, 24 Jul 2020 16:05:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8D8DA2065E for ; Fri, 24 Jul 2020 16:05:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728288AbgGXQE7 (ORCPT ); Fri, 24 Jul 2020 12:04:59 -0400 Received: from 8bytes.org ([81.169.241.247]:60432 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728144AbgGXQEp (ORCPT ); Fri, 24 Jul 2020 12:04:45 -0400 Received: from cap.home.8bytes.org (p5b006776.dip0.t-ipconnect.de [91.0.103.118]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by theia.8bytes.org (Postfix) with ESMTPSA id 2E12EFEE; Fri, 24 Jul 2020 18:04:38 +0200 (CEST) From: Joerg Roedel To: x86@kernel.org Cc: Joerg Roedel , Joerg Roedel , 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 , Sean Christopherson , Martin Radev , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org Subject: [PATCH v5 70/75] x86/head/64: Don't call verify_cpu() on starting APs Date: Fri, 24 Jul 2020 18:03:31 +0200 Message-Id: <20200724160336.5435-71-joro@8bytes.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200724160336.5435-1-joro@8bytes.org> References: <20200724160336.5435-1-joro@8bytes.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Joerg Roedel The APs are not ready to handle exceptions when verify_cpu() is called in secondary_startup_64. Signed-off-by: Joerg Roedel --- arch/x86/include/asm/realmode.h | 1 + arch/x86/kernel/head_64.S | 12 ++++++++++++ arch/x86/realmode/init.c | 6 ++++++ 3 files changed, 19 insertions(+) diff --git a/arch/x86/include/asm/realmode.h b/arch/x86/include/asm/realmode.h index 6590394af309..5c97807c38a4 100644 --- a/arch/x86/include/asm/realmode.h +++ b/arch/x86/include/asm/realmode.h @@ -69,6 +69,7 @@ extern unsigned char startup_32_smp[]; extern unsigned char boot_gdt[]; #else extern unsigned char secondary_startup_64[]; +extern unsigned char secondary_startup_64_no_verify[]; #endif static inline size_t real_mode_size_needed(void) diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index 8d5bf7c568a4..a708107688a2 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -140,6 +140,18 @@ SYM_CODE_START(secondary_startup_64) /* Sanitize CPU configuration */ call verify_cpu + /* + * The secondary_startup_64_no_verify entry point is only used by + * SEV-ES guests. In those guests the call to verify_cpu() would cause + * #VC exceptions which can not be handled at this stage of secondary + * CPU bringup. + * + * All non SEV-ES systems, especially Intel systems, need to execute + * verify_cpu() above to make sure NX is enabled. + */ +SYM_INNER_LABEL(secondary_startup_64_no_verify, SYM_L_GLOBAL) + UNWIND_HINT_EMPTY + /* * Retrieve the modifier (SME encryption mask if SME is active) to be * added to the initial pgdir entry that will be programmed into CR3. diff --git a/arch/x86/realmode/init.c b/arch/x86/realmode/init.c index 61a52b925d15..df701f87ddef 100644 --- a/arch/x86/realmode/init.c +++ b/arch/x86/realmode/init.c @@ -46,6 +46,12 @@ static void sme_sev_setup_real_mode(struct trampoline_header *th) th->flags |= TH_FLAGS_SME_ACTIVE; if (sev_es_active()) { + /* + * Skip the call to verify_cpu() in secondary_startup_64 as it + * will cause #VC exceptions when the AP can't handle them yet. + */ + th->start = (u64) secondary_startup_64_no_verify; + if (sev_es_setup_ap_jump_table(real_mode_header)) panic("Failed to update SEV-ES AP Jump Table"); } -- 2.27.0