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=-6.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 D54E5C433E0 for ; Thu, 4 Feb 2021 01:40:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A133E64F68 for ; Thu, 4 Feb 2021 01:40:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231841AbhBDBkG (ORCPT ); Wed, 3 Feb 2021 20:40:06 -0500 Received: from mail.kernel.org ([198.145.29.99]:45026 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229601AbhBDBkE (ORCPT ); Wed, 3 Feb 2021 20:40:04 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7172E64E31; Thu, 4 Feb 2021 01:39:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1612402764; bh=6M98RcZOM/Vz/I/vJ2XWRs5F5FBLaXaewlLXJ7TVPXs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Y4GMFZkLXl+nnbtq16WfAcOSgIx3UWaTIwtN9anXdO1NCFQpzjpf2zaDc85BspcuE q5daxXWBuzLjdkVDWV6gX7FWP/ZxkD4PZPwlXFJKMqynfYDsyw4aTPgM2hjFhC4DGh uCSQjKnsgAlSnf7s67fIHthyXRWxzs6sDWTaupE6Ex7z/sMwHUVpoeUQrZR78X/4w1 IvR1jq/Hu33MU6rfSMh9EK5JoZ/3Ifh6bVZcK8HDIN6AyjXbVXznlv2J1pQ9WtVNJx +xUuEWXunHnmatS7R2QBp12Q0DTUJkOPozKWTbkQKX+8TImQt5ZEUTOrbTRCM8CASl qkiZXwcBfsSbA== Date: Thu, 4 Feb 2021 03:39:16 +0200 From: Jarkko Sakkinen To: Sean Christopherson Cc: Kai Huang , linux-sgx@vger.kernel.org, kvm@vger.kernel.org, x86@kernel.org, luto@kernel.org, dave.hansen@intel.com, haitao.huang@intel.com, pbonzini@redhat.com, bp@alien8.de, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com Subject: Re: [RFC PATCH v3 08/27] x86/sgx: Initialize virtual EPC driver even when SGX driver is disabled Message-ID: References: <5076ed2c486ac33bfd87dc0e17047a1673692b53.1611634586.git.kai.huang@intel.com> <20210201184040.646ea9923c2119c205b3378d@intel.com> <20210203134906.78b5265502c65f13bacc5e68@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Wed, Feb 03, 2021 at 02:59:47PM -0800, Sean Christopherson wrote: > On Thu, Feb 04, 2021, Jarkko Sakkinen wrote: > > On Wed, Feb 03, 2021 at 01:49:06PM +1300, Kai Huang wrote: > > > What working *incorrectly* thing is related to SGX virtualization? The things > > > SGX virtualization requires (basically just raw EPC allocation) are all in > > > sgx/main.c. > > > > States: > > > > A. SGX driver is unsupported. > > B. SGX driver is supported and initialized correctly. > > C. SGX driver is supported and failed to initialize. > > > > I just thought that KVM should support SGX when we are either in states A > > or B. Even the short summary implies this. It is expected that SGX driver > > initializes correctly if it is supported in the first place. If it doesn't, > > something is probaly seriously wrong. That is something we don't expect in > > a legit system behavior. > > It's legit behavior, and something we (you?) explicitly want to support. See > patch 05, x86/cpu/intel: Allow SGX virtualization without Launch Control support. What I think would be a sane behavior, would be to allow KVM when sgx_drv_init() returns -ENODEV (case A). This happens when LC is not enabled: if (!cpu_feature_enabled(X86_FEATURE_SGX_LC)) return -ENODEV; /Jarkko