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 67B54C433EF for ; Fri, 17 Dec 2021 11:00:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235203AbhLQLAn (ORCPT ); Fri, 17 Dec 2021 06:00:43 -0500 Received: from smtp-out1.suse.de ([195.135.220.28]:36406 "EHLO smtp-out1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233151AbhLQLAh (ORCPT ); Fri, 17 Dec 2021 06:00:37 -0500 Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 9F09F21112; Fri, 17 Dec 2021 11:00:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1639738836; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=U8jtGkkeifhcn5Pwgza9+c5s/LeDEW5/G8c411nJS58=; b=OJnOAhqjFqPEnNsAGR/FxTrf3DFD70DesFTyWdE5pO7UVRUPhjf7blqxpBZQGQkKKHKmxo ZoIMqWsAuJV7bMi2My67Qhx+CsKOkcgpOhBuNshiQrZa9QLeL4qIaIbD8Be8QcRVcEEjJf +ub1N172CJ7zosXd77d5SZKpmjLEL3k= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1639738836; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=U8jtGkkeifhcn5Pwgza9+c5s/LeDEW5/G8c411nJS58=; b=WmTXz8gKVSiGdpvlfJ254SviGWN7UmGQhpO+Zo4fKPsQRvGiUZccqVbMBroyn5787QVe2x SnTy4H4VLU0oTvDg== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 1F07413DC1; Fri, 17 Dec 2021 11:00:36 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id wW3WBdRtvGFCPQAAMHmgww (envelope-from ); Fri, 17 Dec 2021 11:00:36 +0000 Date: Fri, 17 Dec 2021 12:00:34 +0100 From: Joerg Roedel To: Borislav Petkov Cc: Lai Jiangshan , linux-kernel@vger.kernel.org, x86@kernel.org, Lai Jiangshan , Andy Lutomirski , Thomas Gleixner , Ingo Molnar , Dave Hansen , "H. Peter Anvin" , Oleg Nesterov , "Chang S. Bae" , Jan Kiszka , Tom Lendacky Subject: Re: [PATCH 3/3] x86/sev: The code for returning to user space is also in syscall gap Message-ID: References: <20211213042215.3096-1-jiangshanlai@gmail.com> <20211213042215.3096-4-jiangshanlai@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Dec 17, 2021 at 11:30:10AM +0100, Borislav Petkov wrote: > I audited the handful instructions in there and didn't find anything > that would cause a #VC... If the hypervisor decides to mess with the code-page for this path while a CPU is executing it. This will cause a #VC on that CPU and that could hit in the syscall return path. Regards, -- J?rg R?del jroedel@suse.de SUSE Software Solutions Germany GmbH Maxfeldstr. 5 90409 N?rnberg Germany (HRB 36809, AG N?rnberg) Gesch?ftsf?hrer: Ivo Totev