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=ham 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 34198C433FF for ; Wed, 14 Aug 2019 10:54:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C905F206C1 for ; Wed, 14 Aug 2019 10:54:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727226AbfHNKyQ (ORCPT ); Wed, 14 Aug 2019 06:54:16 -0400 Received: from ozlabs.org ([203.11.71.1]:34401 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725996AbfHNKyQ (ORCPT ); Wed, 14 Aug 2019 06:54:16 -0400 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 Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Alexey Kardashevskiy , Anshuman Khandual , Benjamin Herrenschmidt , Christoph Hellwig , Mike Anderson , Paul Mackerras , Ram Pai , Claudio Carvalho , Anshuman Khandual , "Paul E. McKenney" 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 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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