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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 26339C4360C for ; Tue, 8 Oct 2019 09:09:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EA1B3206C2 for ; Tue, 8 Oct 2019 09:09:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="d86V74O5" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730065AbfJHJJo (ORCPT ); Tue, 8 Oct 2019 05:09:44 -0400 Received: from mail.skyhub.de ([5.9.137.197]:56482 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729784AbfJHJJn (ORCPT ); Tue, 8 Oct 2019 05:09:43 -0400 Received: from zn.tnic (p200300EC2F0B510054990CC7734BB19B.dip0.t-ipconnect.de [IPv6:2003:ec:2f0b:5100:5499:cc7:734b:b19b]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 5B0CA1EC0586; Tue, 8 Oct 2019 11:09:41 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1570525781; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=qt4hy0nHJpZzoW+FdanfkOoQrJ3VcoxYAWMats/0cuY=; b=d86V74O523mB29Lrfe7xMwqw93h5ms5psG6yR7hcCoIgxSi5PEiyu47/agTwTCT/IIbWt8 BIPm+2KnntWEpPpFkLTdYVjBIJGPdxzc8Fx1QGdGlywjgUm9KrGXOXOAK2Hv55GNrYdbnX jAVfXJiG0V9CQyCuFjQXb2IFyFQxr34= Date: Tue, 8 Oct 2019 11:09:31 +0200 From: Borislav Petkov To: Sean Christopherson Cc: Jarkko Sakkinen , linux-kernel@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org, akpm@linux-foundation.org, dave.hansen@intel.com, nhorman@redhat.com, npmccallum@redhat.com, serge.ayoun@intel.com, shay.katz-zamir@intel.com, haitao.huang@intel.com, andriy.shevchenko@linux.intel.com, tglx@linutronix.de, kai.svahn@intel.com, josh@joshtriplett.org, luto@kernel.org, kai.huang@intel.com, rientjes@google.com, cedric.xing@intel.com Subject: Re: [PATCH v22 09/24] x86/sgx: Add functions to allocate and free EPC pages Message-ID: <20191008090931.GC14765@zn.tnic> References: <20190903142655.21943-1-jarkko.sakkinen@linux.intel.com> <20190903142655.21943-10-jarkko.sakkinen@linux.intel.com> <20191005164408.GB25699@zn.tnic> <20191007145011.GA18016@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20191007145011.GA18016@linux.intel.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 07, 2019 at 07:50:11AM -0700, Sean Christopherson wrote: > The caller is responsible for ensuring EREMOVE can be safely executed, > e.g. by holding the enclave's lock. lockdep_assert_held() here maybe? > For many ENCLS leafs, EREMOVE included, the CPU requires exclusive access > to the SGX Enclave Control Structures (SECS)[*] and will signal a #GP if > a different logical CPU is already executing an ENCLS leaf that requires > exclusive SECS access. The SGX subsystem uses a per-enclave mutex to > serialize such ENCLS leafs, among other things. > > [*] The SECS is a per-enclave page that resides in the EPC and can only be > directly accessed by the CPU. It's used to track metadata about the > enclave, e.g. number of child pages, base, size, etc... Ok. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette