From patchwork Wed Nov 29 13:33:27 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?b?SsO8cmdlbiBHcm/Dnw==?= X-Patchwork-Id: 13472860 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 lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 0D9D4C4167B for ; Wed, 29 Nov 2023 13:34:09 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.643918.1004489 (Exim 4.92) (envelope-from ) id 1r8KhN-0002QQ-Mh; Wed, 29 Nov 2023 13:33:53 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 643918.1004489; Wed, 29 Nov 2023 13:33:53 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1r8KhN-0002QJ-Jh; Wed, 29 Nov 2023 13:33:53 +0000 Received: by outflank-mailman (input) for mailman id 643918; Wed, 29 Nov 2023 13:33:52 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1r8KhM-0002QC-QE for xen-devel@lists.xenproject.org; Wed, 29 Nov 2023 13:33:52 +0000 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.223.131]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id eed2163a-8ebb-11ee-98e3-6d05b1d4d9a1; Wed, 29 Nov 2023 14:33:51 +0100 (CET) Received: from imap2.dmz-prg2.suse.org (imap2.dmz-prg2.suse.org [10.150.64.98]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id C08DD1FCF3; Wed, 29 Nov 2023 13:33:50 +0000 (UTC) Received: from imap2.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap2.dmz-prg2.suse.org (Postfix) with ESMTPS id 4D8461376F; Wed, 29 Nov 2023 13:33:50 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap2.dmz-prg2.suse.org with ESMTPSA id tvlGEb49Z2V6HwAAn2gu4w (envelope-from ); Wed, 29 Nov 2023 13:33:50 +0000 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: eed2163a-8ebb-11ee-98e3-6d05b1d4d9a1 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1701264830; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=Qd/edhp+5962psCPMPy4XP3r2u443myO08oYjOHlTLA=; b=Pa0EKVY0qxxUd5ai3BkeXQ5O36LsXwze2YUAWSo+uhiqrqu+qQnOMc08tb752X/3bhkI4m zYIZAMIQnrocT+NXv0m6eFE9HhHgm/vc2JCCLVRkIuKeW6Gq8NZCOTCDWChK+a1azg+4be jXG4Qt7cAEBdPBvNbmAiVU1MYGGsVv0= From: Juergen Gross To: linux-kernel@vger.kernel.org, x86@kernel.org, virtualization@lists.linux.dev, kvm@vger.kernel.org Cc: Juergen Gross , Ajay Kaher , Alexey Makhalov , VMware PV-Drivers Reviewers , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , Paolo Bonzini , Wanpeng Li , Vitaly Kuznetsov , Boris Ostrovsky , xen-devel@lists.xenproject.org Subject: [PATCH v5 0/5] 86/paravirt: Get rid of paravirt patching Date: Wed, 29 Nov 2023 14:33:27 +0100 Message-Id: <20231129133332.31043-1-jgross@suse.com> X-Mailer: git-send-email 2.35.3 MIME-Version: 1.0 Authentication-Results: smtp-out2.suse.de; none X-Spamd-Result: default: False [0.90 / 50.00]; ARC_NA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; R_MISSING_CHARSET(2.50)[]; MIME_GOOD(-0.10)[text/plain]; BROKEN_CONTENT_TYPE(1.50)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; RCVD_COUNT_THREE(0.00)[3]; DKIM_SIGNED(0.00)[suse.com:s=susede1]; RCPT_COUNT_TWELVE(0.00)[18]; MID_CONTAINS_FROM(1.00)[]; FUZZY_BLOCKED(0.00)[rspamd.com]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; RCVD_TLS_ALL(0.00)[]; BAYES_HAM(-3.00)[100.00%] This is a small series getting rid of paravirt patching by switching completely to alternative patching for the same functionality. The basic idea is to add the capability to switch from indirect to direct calls via a special alternative patching option. This removes _some_ of the paravirt macro maze, but most of it needs to stay due to the need of hiding the call instructions from the compiler in order to avoid needless register save/restore. What is going away is the nasty stacking of alternative and paravirt patching and (of course) the special .parainstructions linker section. I have tested the series on bare metal and as Xen PV domain to still work. Note that objtool might need some changes to cope with the new indirect call patching mechanism. Additionally some paravirt handling can probably be removed from it. Changes in V5: - addressed Boris' comments - rebased on top of the tip/master branch Changes in V4: - addressed Boris' comments in patch 1 - fixed bugs found by kernel test robot (patch 2) Changes in V3: - split v2 patch 3 into 2 patches as requested by Peter and Ingo Changes in V2: - split last patch into 2 - rebase of patch 2 as suggested by Peter - addressed Peter's comments for patch 3 Juergen Gross (5): x86/paravirt: introduce ALT_NOT_XEN x86/paravirt: move some functions and defines to alternative x86/alternative: add indirect call patching x86/paravirt: switch mixed paravirt/alternative calls to alternative_2 x86/paravirt: remove no longer needed paravirt patching code arch/x86/include/asm/alternative.h | 30 +++++- arch/x86/include/asm/paravirt.h | 77 ++++--------- arch/x86/include/asm/paravirt_types.h | 85 +++++---------- arch/x86/include/asm/qspinlock_paravirt.h | 4 +- arch/x86/include/asm/text-patching.h | 12 --- arch/x86/kernel/alternative.c | 125 ++++++++++------------ arch/x86/kernel/callthunks.c | 17 ++- arch/x86/kernel/kvm.c | 4 +- arch/x86/kernel/module.c | 20 +--- arch/x86/kernel/paravirt.c | 54 ++-------- arch/x86/kernel/vmlinux.lds.S | 13 --- arch/x86/tools/relocs.c | 2 +- arch/x86/xen/irq.c | 2 +- 13 files changed, 161 insertions(+), 284 deletions(-)