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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DFA7CC00144 for ; Mon, 1 Aug 2022 20:24:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232599AbiHAUYG (ORCPT ); Mon, 1 Aug 2022 16:24:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38098 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231190AbiHAUYF (ORCPT ); Mon, 1 Aug 2022 16:24:05 -0400 Received: from smtp-out2.suse.de (smtp-out2.suse.de [IPv6:2001:67c:2178:6::1d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9BEC8B3 for ; Mon, 1 Aug 2022 13:24:04 -0700 (PDT) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out2.suse.de (Postfix) with ESMTP id 51FE91FA5E; Mon, 1 Aug 2022 20:24:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1659385443; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=R7dmq4djzkOFR69RK7c8s+fuWDxrZrVFcqjlq0EfVNQ=; b=aYz/EljHWSiJAfHsWfC1bCTaisxCjY935FQtanU9jleQldNznciMMANHQBY77g75v0HdVe 3d3e8swYNxSo2wjqXzjCKkLCMPmOWdDMftv2dpH0HoKDoRaaNTlY1cqUiJfm5z31ZM+QG7 e96tf4LEe6fXiPiVopzxyhcTU4IVEn8= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1659385443; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=R7dmq4djzkOFR69RK7c8s+fuWDxrZrVFcqjlq0EfVNQ=; b=b2F5pSaSfLAC3bfALL7ErTvTg2ZIRyWeohxi7oQ8PALeotaHL13CssPH+b50WBRQklpzZc VJWKMzr3tsOllpBg== Received: from kitsune.suse.cz (kitsune.suse.cz [10.100.12.127]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id 960442C141; Mon, 1 Aug 2022 20:24:02 +0000 (UTC) Date: Mon, 1 Aug 2022 22:24:01 +0200 From: Michal =?iso-8859-1?Q?Such=E1nek?= To: Nayna Cc: axboe@kernel.dk, nayna@linux.ibm.com, linux-block@vger.kernel.org, jonathan.derrick@linux.dev, brking@linux.vnet.ibm.com, akpm@linux-foundation.org, linuxppc-dev@lists.ozlabs.org, gjoyce@ibm.com, gjoyce@linux.vnet.ibm.com, Michael Ellerman , Nick Piggin , Christophe Leroy Subject: Re: [PATCH v3 1/2] lib: generic accessor functions for arch keystore Message-ID: <20220801202401.GZ17705@kitsune.suse.cz> References: <20220801123426.585801-1-gjoyce@linux.vnet.ibm.com> <20220801123426.585801-2-gjoyce@linux.vnet.ibm.com> <20220801134018.GY17705@kitsune.suse.cz> <61ebf904-8ce1-eeac-888a-4040711e7903@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <61ebf904-8ce1-eeac-888a-4040711e7903@linux.vnet.ibm.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Mon, Aug 01, 2022 at 03:45:45PM -0400, Nayna wrote: > > On 8/1/22 09:40, Michal Suchánek wrote: > > Hello, > > > > On Mon, Aug 01, 2022 at 07:34:25AM -0500, gjoyce@linux.vnet.ibm.com wrote: > > > From: Greg Joyce > > > > > > Generic kernel subsystems may rely on platform specific persistent > > > KeyStore to store objects containing sensitive key material. In such case, > > > they need to access architecture specific functions to perform read/write > > > operations on these variables. > > > > > > Define the generic variable read/write prototypes to be implemented by > > > architecture specific versions. The default(weak) implementations of > > > these prototypes return -EOPNOTSUPP unless overridden by architecture > > > versions. > > > > > > Signed-off-by: Greg Joyce > > > --- > > > include/linux/arch_vars.h | 23 +++++++++++++++++++++++ > > > lib/Makefile | 2 +- > > > lib/arch_vars.c | 25 +++++++++++++++++++++++++ > > > 3 files changed, 49 insertions(+), 1 deletion(-) > > > create mode 100644 include/linux/arch_vars.h > > > create mode 100644 lib/arch_vars.c > > > > > > diff --git a/include/linux/arch_vars.h b/include/linux/arch_vars.h > > > new file mode 100644 > > > index 000000000000..9c280ff9432e > > > --- /dev/null > > > +++ b/include/linux/arch_vars.h > > > @@ -0,0 +1,23 @@ > > > +/* SPDX-License-Identifier: GPL-2.0 */ > > > +/* > > > + * Platform variable opearations. > > > + * > > > + * Copyright (C) 2022 IBM Corporation > > > + * > > > + * These are the accessor functions (read/write) for architecture specific > > > + * variables. Specific architectures can provide overrides. > > > + * > > > + */ > > > + > > > +#include > > > + > > > +enum arch_variable_type { > > > + ARCH_VAR_OPAL_KEY = 0, /* SED Opal Authentication Key */ > > > + ARCH_VAR_OTHER = 1, /* Other type of variable */ > > > + ARCH_VAR_MAX = 1, /* Maximum type value */ > > > +}; > > > + > > > +int arch_read_variable(enum arch_variable_type type, char *varname, > > > + void *varbuf, u_int *varlen); > > > +int arch_write_variable(enum arch_variable_type type, char *varname, > > > + void *varbuf, u_int varlen); > > > diff --git a/lib/Makefile b/lib/Makefile > > > index f99bf61f8bbc..b90c4cb0dbbb 100644 > > > --- a/lib/Makefile > > > +++ b/lib/Makefile > > > @@ -48,7 +48,7 @@ obj-y += bcd.o sort.o parser.o debug_locks.o random32.o \ > > > bsearch.o find_bit.o llist.o memweight.o kfifo.o \ > > > percpu-refcount.o rhashtable.o \ > > > once.o refcount.o usercopy.o errseq.o bucket_locks.o \ > > > - generic-radix-tree.o > > > + generic-radix-tree.o arch_vars.o > > > obj-$(CONFIG_STRING_SELFTEST) += test_string.o > > > obj-y += string_helpers.o > > > obj-$(CONFIG_TEST_STRING_HELPERS) += test-string_helpers.o > > > diff --git a/lib/arch_vars.c b/lib/arch_vars.c > > > new file mode 100644 > > > index 000000000000..e6f16d7d09c1 > > > --- /dev/null > > > +++ b/lib/arch_vars.c > > > @@ -0,0 +1,25 @@ > > > +// SPDX-License-Identifier: GPL-2.0-only > > > +/* > > > + * Platform variable operations. > > > + * > > > + * Copyright (C) 2022 IBM Corporation > > > + * > > > + * These are the accessor functions (read/write) for architecture specific > > > + * variables. Specific architectures can provide overrides. > > > + * > > > + */ > > > + > > > +#include > > > +#include > > > + > > > +int __weak arch_read_variable(enum arch_variable_type type, char *varname, > > > + void *varbuf, u_int *varlen) > > > +{ > > > + return -EOPNOTSUPP; > > > +} > > > + > > > +int __weak arch_write_variable(enum arch_variable_type type, char *varname, > > > + void *varbuf, u_int varlen) > > > +{ > > > + return -EOPNOTSUPP; > > > +} > > > -- > > Doesn't EFI already have some variables? > > > > And even powernv? > > > > Shouldn't this generalize the already existing variables? > > > > Or move to powerpc and at least generalize the powerpc ones? > > Yes, EFI and PowerNV do have variables, but I am not exactly clear about > your reference to them in this context. What do you mean by generalize > already existing variables ? > > This interface is actually generalizing calls to access platform specific > keystores. It is explained in cover letter that this patch is defining > generic interface and these are default implementations which needs to be > overridden by arch specific versions.  For PowerVM PLPAR Platform KeyStore, > the arch specific version is implemented in Patch 2. For powervm, not powernv. If it's not generic enough to cover even powerpc-specific keystores does such generalization even need to exist? > > Access to EFI variables should be implemented by EFI arch specific interface > and PowerNV will have to do the same if it needs to. If such generic interface is desirable it should cover the existing architectures I think. Otherwise how can you tell if it's usable there? Thanks Michal