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=-18.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL 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 BBDF7C433DB for ; Wed, 27 Jan 2021 13:32:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 74F44207B3 for ; Wed, 27 Jan 2021 13:32:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S313349AbhAZWf2 (ORCPT ); Tue, 26 Jan 2021 17:35:28 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50252 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730154AbhAZRFM (ORCPT ); Tue, 26 Jan 2021 12:05:12 -0500 Received: from mail-pf1-x434.google.com (mail-pf1-x434.google.com [IPv6:2607:f8b0:4864:20::434]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 02833C061573 for ; Tue, 26 Jan 2021 09:00:54 -0800 (PST) Received: by mail-pf1-x434.google.com with SMTP id w14so10775285pfi.2 for ; Tue, 26 Jan 2021 09:00:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=ENlLmc+JejdwJwWT2OL+d2JHDx3OTLzS/BlF7JGq2nA=; b=aZ/ShnW8eg0eJ5zhC4gY7+YObNwS5lRBPfbAGJ4ULjVLsF55wBXe9n8giN7CT2SM/S /DhG85ScJiXlL0JBakWStEdk5M3H2FD/nemAq/AIG+jo2/oEzN/nFlhqJHdRvGmX5ckg f//nXQd0qCvuQymR64nsDY27lBtZBNl1KEQ5mE47uORe6pr9IRdvs6ewoYwBbiEzzzB5 I4t9ku9OHD8eAp6XM9e87sB3533UzU8oa+xG5YS+i0xD3Wp2LPVifKg73pICaNyKzMma OE+Ps9wJU+TuEfyzftqI/wrZ6KVCmQihFVoNg8oo3Ng6DqQCbCpdLgADSyKcrgU5TlRS 66CA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=ENlLmc+JejdwJwWT2OL+d2JHDx3OTLzS/BlF7JGq2nA=; b=b1WMEliPutdA3ckTpFKGwBYqw1RAmDOxefKKk511+a2BRMySYXRQsWnY/Tqge1paKy HnRoQxdDlUwfpozQ8ACeVghxcZoIq4A3Qn0ZF4kAguF/NcGUc+w0w58b6ZUBN5zp/syZ CwBl1ZvZGcPLyYk6CHk35p3ofWh5uBaug/DFMW0Ul+b2Luk+W1+Gfvuubg0LVhN2ZgsE 27hyVK026opubFtZPc4dUGJdNwu3y8khuDjVxwRWUMAf/ZcJsLVNnHxcFm6PqQ1y0toq dhyzx21nXz83xTkUR+pNP3IQAuTXgAOg6QlGUrYu55pB0+wRiJCRkNu+g4LIZ1B/UzrX 09sA== X-Gm-Message-State: AOAM530syyRyKCZVSb5W+gyis9d3dO1scQZZlHgTUoPu6vTwTMjP6K3F T/57GGnwF9Wva3qvFsnYcmd9EA== X-Google-Smtp-Source: ABdhPJyWOBKzyzUyfMtkAbOdRuR4zb43p89ImjgpolqyL65mgDafFCN9gIbSLho2Ez7hZxhmbwoDxQ== X-Received: by 2002:a65:5283:: with SMTP id y3mr6502558pgp.174.1611680453424; Tue, 26 Jan 2021 09:00:53 -0800 (PST) Received: from google.com ([2620:15c:f:10:1ea0:b8ff:fe73:50f5]) by smtp.gmail.com with ESMTPSA id a2sm5382885pgq.94.2021.01.26.09.00.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 26 Jan 2021 09:00:52 -0800 (PST) Date: Tue, 26 Jan 2021 09:00:45 -0800 From: Sean Christopherson To: Dave Hansen Cc: Kai Huang , linux-sgx@vger.kernel.org, kvm@vger.kernel.org, x86@kernel.org, jarkko@kernel.org, luto@kernel.org, haitao.huang@intel.com, pbonzini@redhat.com, bp@alien8.de, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, jethro@fortanix.com, b.thiel@posteo.de Subject: Re: [RFC PATCH v3 07/27] x86/cpu/intel: Allow SGX virtualization without Launch Control support Message-ID: References: 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 Tue, Jan 26, 2021, Dave Hansen wrote: > > - enable_sgx = cpu_has(c, X86_FEATURE_SGX) && > > - cpu_has(c, X86_FEATURE_SGX_LC) && > > - IS_ENABLED(CONFIG_X86_SGX); > > + enable_sgx_any = cpu_has(c, X86_FEATURE_SGX) && > > + cpu_has(c, X86_FEATURE_SGX1) && > > + IS_ENABLED(CONFIG_X86_SGX); > > The X86_FEATURE_SGX1 check seems to have snuck in here. Why? It's a best effort check to handle the scenario where SGX is enabled by BIOS, but was disabled by hardware in response to a machine check bank being disabled. Adding a check on SGX1 should be in a different patch. I thought we had a dicscussion about why the check was omitted in the merge of bare metal support, but I can't find any such thread. > > + enable_sgx_driver = enable_sgx_any && > > + cpu_has(c, X86_FEATURE_SGX_LC); > > + enable_sgx_kvm = enable_sgx_any && enable_vmx && > > + IS_ENABLED(CONFIG_X86_SGX_KVM); > > > > if (msr & FEAT_CTL_LOCKED) > > goto update_caps; > > @@ -136,15 +146,18 @@ void init_ia32_feat_ctl(struct cpuinfo_x86 *c) > > * i.e. KVM is enabled, to avoid unnecessarily adding an attack vector > > * for the kernel, e.g. using VMX to hide malicious code. > > */ > > - if (cpu_has(c, X86_FEATURE_VMX) && IS_ENABLED(CONFIG_KVM_INTEL)) { > > + if (enable_vmx) { > > msr |= FEAT_CTL_VMX_ENABLED_OUTSIDE_SMX; > > > > if (tboot) > > msr |= FEAT_CTL_VMX_ENABLED_INSIDE_SMX; > > } > > > > - if (enable_sgx) > > - msr |= FEAT_CTL_SGX_ENABLED | FEAT_CTL_SGX_LC_ENABLED; > > + if (enable_sgx_kvm || enable_sgx_driver) { > > + msr |= FEAT_CTL_SGX_ENABLED; > > + if (enable_sgx_driver) > > + msr |= FEAT_CTL_SGX_LC_ENABLED; > > + } > > > > wrmsrl(MSR_IA32_FEAT_CTL, msr); > > > > @@ -167,10 +180,29 @@ void init_ia32_feat_ctl(struct cpuinfo_x86 *c) > > } > > > > update_sgx: > > - if (!(msr & FEAT_CTL_SGX_ENABLED) || > > - !(msr & FEAT_CTL_SGX_LC_ENABLED) || !enable_sgx) { > > - if (enable_sgx) > > - pr_err_once("SGX disabled by BIOS\n"); > > + if (!(msr & FEAT_CTL_SGX_ENABLED)) { > > + if (enable_sgx_kvm || enable_sgx_driver) > > + pr_err_once("SGX disabled by BIOS.\n"); > > clear_cpu_cap(c, X86_FEATURE_SGX); > > + return; > > + } > > > Isn't there a pr_fmt here already? Won't these just look like: > > sgx: SGX disabled by BIOS. > > That seems a bit silly. Eh, I like the explicit "SGX" to clarify that the hardware feature was disabled.