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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 9EB21C433FF for ; Wed, 14 Aug 2019 10:56:27 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 289EC206C1 for ; Wed, 14 Aug 2019 10:56:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 289EC206C1 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 467mjN70pzzDqsC for ; Wed, 14 Aug 2019 20:56:24 +1000 (AEST) Received: from ozlabs.org (bilbo.ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 467mft2y4XzDqP3 for ; Wed, 14 Aug 2019 20:54:14 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 467mfs4Z3Mz9sN1; Wed, 14 Aug 2019 20:54:13 +1000 (AEST) From: Michael Ellerman To: Thiago Jung Bauermann Subject: Re: [PATCH v3 08/16] powerpc/pseries/svm: Use shared memory for LPPACA structures In-Reply-To: <87sgq6gium.fsf@morokweng.localdomain> References: <20190806052237.12525-1-bauerman@linux.ibm.com> <20190806052237.12525-9-bauerman@linux.ibm.com> <875zn2sgqs.fsf@concordia.ellerman.id.au> <87sgq6gium.fsf@morokweng.localdomain> Date: Wed, 14 Aug 2019 20:54:12 +1000 Message-ID: <87tvakqap7.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Anshuman Khandual , Alexey Kardashevskiy , Mike Anderson , Ram Pai , linux-kernel@vger.kernel.org, Claudio Carvalho , Paul Mackerras , "Paul E. McKenney" , linuxppc-dev@lists.ozlabs.org, Christoph Hellwig , Anshuman Khandual Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Thiago Jung Bauermann writes: > Michael Ellerman writes: >> Thiago Jung Bauermann writes: >>> From: Anshuman Khandual >>> >>> LPPACA structures need to be shared with the host. Hence they need to be in >>> shared memory. Instead of allocating individual chunks of memory for a >>> given structure from memblock, a contiguous chunk of memory is allocated >>> and then converted into shared memory. Subsequent allocation requests will >>> come from the contiguous chunk which will be always shared memory for all >>> structures. >>> >>> While we are able to use a kmem_cache constructor for the Debug Trace Log, >>> LPPACAs are allocated very early in the boot process (before SLUB is >>> available) so we need to use a simpler scheme here. >>> >>> Introduce helper is_svm_platform() which uses the S bit of the MSR to tell >>> whether we're running as a secure guest. >>> >>> Signed-off-by: Anshuman Khandual >>> Signed-off-by: Thiago Jung Bauermann >>> --- >>> arch/powerpc/include/asm/svm.h | 26 ++++++++++++++++++++ >>> arch/powerpc/kernel/paca.c | 43 +++++++++++++++++++++++++++++++++- >>> 2 files changed, 68 insertions(+), 1 deletion(-) >>> >>> diff --git a/arch/powerpc/include/asm/svm.h b/arch/powerpc/include/asm/svm.h >>> new file mode 100644 >>> index 000000000000..fef3740f46a6 >>> --- /dev/null >>> +++ b/arch/powerpc/include/asm/svm.h >>> @@ -0,0 +1,26 @@ >>> +/* SPDX-License-Identifier: GPL-2.0+ */ >>> +/* >>> + * SVM helper functions >>> + * >>> + * Copyright 2019 Anshuman Khandual, IBM Corporation. >> >> Are we sure this copyright date is correct? > > I may be confused about which year the copyright refers to. I thought it > was the year when the patch was committed. If it is the first time the > patch was published then this one should be 2018. I'm not a lawyer etc. but AIUI the date above is about the authorship, ie. when it was originally written, not when it was published or committed. In general I don't think it matters too much, but in this case I'm pretty sure Anshuman can't have possibly written it in 2019 on behalf of IBM :) So we can either change the date to 2018, or drop his name and just say it's copyright 2019 by IBM. cheers