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=-14.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 841BEC43466 for ; Fri, 18 Sep 2020 08:53:04 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 11E0A208C3 for ; Fri, 18 Sep 2020 08:53:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="nppkrg0X"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="RNh/kppb" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 11E0A208C3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=mE/Q8pmXZwnIYZG6+0I0or6BKgPRQykNb78lp40AC+4=; b=nppkrg0XQfKk30CBwuZ8HQVUn L+T+KvGhil8JOgewkR5Uq2AJbLqmMCxheaBmrH5GRB5tOi1uz0CpvgCHIa8K6mu3cmTwvSoVh4GHt CF8ZYQ62oiBweugUeN0v1jFjyYvsZHksdgKjfmtHo+LpzVYm3rVEPdy4Iie/D1z7DWexxWz8ThuRi CW+Xm0tM4P6H+bnY5J1p9R+PeP7mjbZ3ij39Vc+TImg3lc3QdAXZe4a98YInrmXzixOa2NKW4HDrM DsylCN2gM/NNtKH11ztAQv9lgDhx/utv97AcJfiFjhSofkZ98elnU+RriKPx9IswTbnFrZ8AZeg+b RFCBrpKvg==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kJC77-0005V7-GH; Fri, 18 Sep 2020 08:51:29 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kJC73-0005UM-UP for linux-arm-kernel@lists.infradead.org; Fri, 18 Sep 2020 08:51:27 +0000 Received: from willie-the-truck (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 97F6D208B8; Fri, 18 Sep 2020 08:51:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600419083; bh=xSuljIaVzLXu/fP2mE0aGU32cBoHqrhtfIi4pwf6ku0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=RNh/kppbBRNafdG5SxQjmgKu6lqLfCQO68yvGZ2XZ0suKr94KuMwIOD6RSsQFvnKI U+4FYyhlZN9nx3UowWA8v4x4ZWdHVqoC6dPHOwb405yYU93zomqj0i4XFen2uxOpKC fkimNUzViQv7Z0sKBHoDStVpoTLvWQ417k2DNin0= Date: Fri, 18 Sep 2020 09:51:17 +0100 From: Will Deacon To: David Brazdil Subject: Re: [PATCH v3 01/11] kvm: arm64: Partially link nVHE hyp code, simplify HYPCOPY Message-ID: <20200918085116.GA30834@willie-the-truck> References: <20200916173439.32265-1-dbrazdil@google.com> <20200916173439.32265-2-dbrazdil@google.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200916173439.32265-2-dbrazdil@google.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200918_045126_141820_7C036D27 X-CRM114-Status: GOOD ( 28.58 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Suzuki K Poulose , Catalin Marinas , linux-kernel@vger.kernel.org, James Morse , linux-arm-kernel@lists.infradead.org, Marc Zyngier , Tejun Heo , Dennis Zhou , Christoph Lameter , kernel-team@android.com, kvmarm@lists.cs.columbia.edu, Julien Thierry Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Sep 16, 2020 at 06:34:29PM +0100, David Brazdil wrote: > Relying on objcopy to prefix the ELF section names of the nVHE hyp code > is brittle and prevents us from using wildcards to match specific > section names. > > Improve the build rules by partially linking all '.nvhe.o' files and > prefixing their ELF section names using a linker script. Continue using > objcopy for prefixing ELF symbol names. > > One immediate advantage of this approach is that all subsections > matching a pattern can be merged into a single prefixed section, eg. > .text and .text.* can be linked into a single '.hyp.text'. This removes > the need for -fno-reorder-functions on GCC and will be useful in the > future too: LTO builds use .text subsections, compilers routinely > generate .rodata subsections, etc. > > Partially linking all hyp code into a single object file also makes it > easier to analyze. > > Signed-off-by: David Brazdil > --- > arch/arm64/include/asm/hyp_image.h | 24 ++++++++++++ > arch/arm64/kvm/hyp/nvhe/Makefile | 60 ++++++++++++++++-------------- > arch/arm64/kvm/hyp/nvhe/hyp.lds.S | 13 +++++++ > 3 files changed, 70 insertions(+), 27 deletions(-) > create mode 100644 arch/arm64/include/asm/hyp_image.h > create mode 100644 arch/arm64/kvm/hyp/nvhe/hyp.lds.S > > diff --git a/arch/arm64/include/asm/hyp_image.h b/arch/arm64/include/asm/hyp_image.h > new file mode 100644 > index 000000000000..5b1e3b9ef376 > --- /dev/null > +++ b/arch/arm64/include/asm/hyp_image.h > @@ -0,0 +1,24 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +/* > + * Copyright (C) 2020 Google LLC. > + * Written by David Brazdil > + */ > + > +#ifndef __ARM64_HYP_IMAGE_H__ > +#define __ARM64_HYP_IMAGE_H__ > + > +#ifdef LINKER_SCRIPT > + > +/* > + * KVM nVHE ELF section names are prefixed with .hyp, to separate them > + * from the kernel proper. > + */ > +#define HYP_SECTION_NAME(NAME) .hyp##NAME > + > +/* Defines an ELF hyp section from input section @NAME and its subsections. */ > +#define HYP_SECTION(NAME) \ > + HYP_SECTION_NAME(NAME) : { *(NAME NAME##.[0-9a-zA-Z_]*) } I still don't get why we can't just use NAME ## .* for the regex here. That matches what we do elsewhere for linker script wildcarding, e.g. .rodata.*, .init.text.* ... in asm-generic/vmlinux.lds.h. Why is it different for these sections? > + > +#endif /* LINKER_SCRIPT */ > + > +#endif /* __ARM64_HYP_IMAGE_H__ */ > diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile > index aef76487edc2..2b27b60182f9 100644 > --- a/arch/arm64/kvm/hyp/nvhe/Makefile > +++ b/arch/arm64/kvm/hyp/nvhe/Makefile > @@ -10,40 +10,46 @@ obj-y := timer-sr.o sysreg-sr.o debug-sr.o switch.o tlb.o hyp-init.o > obj-y += ../vgic-v3-sr.o ../aarch32.o ../vgic-v2-cpuif-proxy.o ../entry.o \ > ../fpsimd.o ../hyp-entry.o > > -obj-y := $(patsubst %.o,%.hyp.o,$(obj-y)) > -extra-y := $(patsubst %.hyp.o,%.hyp.tmp.o,$(obj-y)) > +## > +## Build rules for compiling nVHE hyp code > +## Output of this folder is `kvm_nvhe.o`, a partially linked object > +## file containing all nVHE hyp code and data. > +## > > -$(obj)/%.hyp.tmp.o: $(src)/%.c FORCE > +hyp-obj := $(patsubst %.o,%.nvhe.o,$(obj-y)) > +obj-y := kvm_nvhe.o > +extra-y := $(hyp-obj) kvm_nvhe.tmp.o hyp.lds > + > +# 1) Compile all source files to `.nvhe.o` object files. The file extension > +# avoids file name clashes for files shared with VHE. > +$(obj)/%.nvhe.o: $(src)/%.c FORCE > $(call if_changed_rule,cc_o_c) > -$(obj)/%.hyp.tmp.o: $(src)/%.S FORCE > +$(obj)/%.nvhe.o: $(src)/%.S FORCE > $(call if_changed_rule,as_o_S) > -$(obj)/%.hyp.o: $(obj)/%.hyp.tmp.o FORCE > - $(call if_changed,hypcopy) > > -# Disable reordering functions by GCC (enabled at -O2). > -# This pass puts functions into '.text.*' sections to aid the linker > -# in optimizing ELF layout. See HYPCOPY comment below for more info. > -ccflags-y += $(call cc-option,-fno-reorder-functions) > +# 2) Compile linker script. > +$(obj)/hyp.lds: $(src)/hyp.lds.S FORCE > + $(call if_changed_dep,cpp_lds_S) You need a .gitignore file listing hyp.lds, otherwise some idiot will end up committing it. I definitely didn't do that when playing around with this series. Nope. Not at all. With that, and the regex resolved: Acked-by: Will Deacon Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel