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=-3.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 8E040C433E6 for ; Wed, 15 Jul 2020 08:48:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6884620663 for ; Wed, 15 Jul 2020 08:48:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="WW8YoVzk" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730435AbgGOIsN (ORCPT ); Wed, 15 Jul 2020 04:48:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55214 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729377AbgGOIsN (ORCPT ); Wed, 15 Jul 2020 04:48:13 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0709CC061755; Wed, 15 Jul 2020 01:48:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=2hxetUaUv/Sl3bYl89m2PSXLP2Q6opXZZBO3eaTSzBk=; b=WW8YoVzkyFTNUO9zvgWo2fwDzD Lqc0L2K1pu7x6Aoez048E/g4JFKPhwgeWkwrPWMYTj0CoOm8R+ljR0SxX8amd6+eXuJX/CS9zmIBP 943484iheiZFam8/iMWZxomMZnKu3B5V7HkQa0b7F7vNyE0OOpFL410o1HVKURFQzX7WfnAynrSRq tPJdTgs6yJAUqRMlfeetU4QyxaCqG8Ix+u5Od6IdthJP8fJ/XDceikh2bSZdYT0a33CAF8phFpOoh sMIvkBLrFGVTnISkOolA4A/ruDGcTPVcQFmN13Opjlbj/piWe6oHWmXOLLCQdHnbZ2fe1g5NLgJOf CE8x9iDA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jvd50-0007wY-B1; Wed, 15 Jul 2020 08:47:54 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id BB2203028C8; Wed, 15 Jul 2020 10:47:52 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id A994F2145CCC2; Wed, 15 Jul 2020 10:47:52 +0200 (CEST) Date: Wed, 15 Jul 2020 10:47:52 +0200 From: Peter Zijlstra To: Joerg Roedel Cc: x86@kernel.org, Joerg Roedel , hpa@zytor.com, Andy Lutomirski , Dave Hansen , 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: Re: [PATCH v4 63/75] x86/sev-es: Handle #DB Events Message-ID: <20200715084752.GD10769@hirez.programming.kicks-ass.net> References: <20200714120917.11253-1-joro@8bytes.org> <20200714120917.11253-64-joro@8bytes.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200714120917.11253-64-joro@8bytes.org> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Tue, Jul 14, 2020 at 02:09:05PM +0200, Joerg Roedel wrote: > @@ -1028,6 +1036,16 @@ DEFINE_IDTENTRY_VC_SAFE_STACK(exc_vmm_communication) > struct ghcb *ghcb; > > lockdep_assert_irqs_disabled(); > + > + /* > + * #DB is special and needs to be handled outside of the intrumentation_begin()/end(). > + * Otherwise the #VC handler could be raised recursivly. > + */ > + if (error_code == SVM_EXIT_EXCP_BASE + X86_TRAP_DB) { > + vc_handle_trap_db(regs); > + return; > + } > + > instrumentation_begin(); Wait what?! That makes no sense what so ever.