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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 7C85AC433E0 for ; Fri, 12 Mar 2021 12:38:41 +0000 (UTC) Received: from smtp1.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 32D9664D73 for ; Fri, 12 Mar 2021 12:38:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 32D9664D73 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=8bytes.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=virtualization-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by smtp1.osuosl.org (Postfix) with ESMTP id 34F1784557; Fri, 12 Mar 2021 12:38:40 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp1.osuosl.org ([127.0.0.1]) by localhost (smtp1.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Pqp1B4f0dpah; Fri, 12 Mar 2021 12:38:39 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [IPv6:2605:bc80:3010:104::8cd3:938]) by smtp1.osuosl.org (Postfix) with ESMTP id 99D5D84552; Fri, 12 Mar 2021 12:38:38 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 95A7BC0018; Fri, 12 Mar 2021 12:38:37 +0000 (UTC) Received: from smtp3.osuosl.org (smtp3.osuosl.org [140.211.166.136]) by lists.linuxfoundation.org (Postfix) with ESMTP id 107EDC0001 for ; Fri, 12 Mar 2021 12:38:36 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp3.osuosl.org (Postfix) with ESMTP id E3010605E1 for ; Fri, 12 Mar 2021 12:38:35 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp3.osuosl.org ([127.0.0.1]) by localhost (smtp3.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id jvo5l137tlea for ; Fri, 12 Mar 2021 12:38:35 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.8.0 Received: from theia.8bytes.org (8bytes.org [IPv6:2a01:238:4383:600:38bc:a715:4b6d:a889]) by smtp3.osuosl.org (Postfix) with ESMTPS id DC6EC605DD for ; Fri, 12 Mar 2021 12:38:34 +0000 (UTC) Received: from cap.home.8bytes.org (p549adcf6.dip0.t-ipconnect.de [84.154.220.246]) (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 001EC39B; Fri, 12 Mar 2021 13:38:30 +0100 (CET) From: Joerg Roedel To: x86@kernel.org Subject: [PATCH v3 1/8] x86/boot/compressed/64: Cleanup exception handling before booting kernel Date: Fri, 12 Mar 2021 13:38:17 +0100 Message-Id: <20210312123824.306-2-joro@8bytes.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210312123824.306-1-joro@8bytes.org> References: <20210312123824.306-1-joro@8bytes.org> MIME-Version: 1.0 Cc: kvm@vger.kernel.org, Peter Zijlstra , Dave Hansen , virtualization@lists.linux-foundation.org, Arvind Sankar , hpa@zytor.com, Jiri Slaby , Joerg Roedel , David Rientjes , Martin Radev , Tom Lendacky , Joerg Roedel , Kees Cook , Cfir Cohen , Andy Lutomirski , Dan Williams , Juergen Gross , Mike Stunes , Sean Christopherson , linux-kernel@vger.kernel.org, Masami Hiramatsu , Erdem Aktas X-BeenThere: virtualization@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux virtualization List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: virtualization-bounces@lists.linux-foundation.org Sender: "Virtualization" From: Joerg Roedel Disable the exception handling before booting the kernel to make sure any exceptions that happen during early kernel boot are not directed to the pre-decompression code. Signed-off-by: Joerg Roedel --- arch/x86/boot/compressed/idt_64.c | 14 ++++++++++++++ arch/x86/boot/compressed/misc.c | 7 ++----- arch/x86/boot/compressed/misc.h | 6 ++++++ 3 files changed, 22 insertions(+), 5 deletions(-) diff --git a/arch/x86/boot/compressed/idt_64.c b/arch/x86/boot/compressed/idt_64.c index 804a502ee0d2..9b93567d663a 100644 --- a/arch/x86/boot/compressed/idt_64.c +++ b/arch/x86/boot/compressed/idt_64.c @@ -52,3 +52,17 @@ void load_stage2_idt(void) load_boot_idt(&boot_idt_desc); } + +void cleanup_exception_handling(void) +{ + /* + * Flush GHCB from cache and map it encrypted again when running as + * SEV-ES guest. + */ + sev_es_shutdown_ghcb(); + + /* Set a null-idt, disabling #PF and #VC handling */ + boot_idt_desc.size = 0; + boot_idt_desc.address = 0; + load_boot_idt(&boot_idt_desc); +} diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c index 267e7f93050e..cc9fd0e8766a 100644 --- a/arch/x86/boot/compressed/misc.c +++ b/arch/x86/boot/compressed/misc.c @@ -443,11 +443,8 @@ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap, handle_relocations(output, output_len, virt_addr); debug_putstr("done.\nBooting the kernel.\n"); - /* - * Flush GHCB from cache and map it encrypted again when running as - * SEV-ES guest. - */ - sev_es_shutdown_ghcb(); + /* Disable exception handling before booting the kernel */ + cleanup_exception_handling(); return output; } diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h index 901ea5ebec22..e5612f035498 100644 --- a/arch/x86/boot/compressed/misc.h +++ b/arch/x86/boot/compressed/misc.h @@ -155,6 +155,12 @@ extern pteval_t __default_kernel_pte_mask; extern gate_desc boot_idt[BOOT_IDT_ENTRIES]; extern struct desc_ptr boot_idt_desc; +#ifdef CONFIG_X86_64 +void cleanup_exception_handling(void); +#else +static inline void cleanup_exception_handling(void) { } +#endif + /* IDT Entry Points */ void boot_page_fault(void); void boot_stage1_vc(void); -- 2.30.1 _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization