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=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 1ACF6C388F9 for ; Sat, 21 Nov 2020 12:25:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CF0C222226 for ; Sat, 21 Nov 2020 12:25:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727337AbgKUMZU (ORCPT ); Sat, 21 Nov 2020 07:25:20 -0500 Received: from disco-boy.misterjones.org ([51.254.78.96]:37550 "EHLO disco-boy.misterjones.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727191AbgKUMZU (ORCPT ); Sat, 21 Nov 2020 07:25:20 -0500 X-Greylist: delayed 2676 seconds by postgrey-1.27 at vger.kernel.org; Sat, 21 Nov 2020 07:25:18 EST Received: from disco-boy.misterjones.org ([51.254.78.96] helo=www.loen.fr) by disco-boy.misterjones.org with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.94) (envelope-from ) id 1kgRFo-00CVLU-BN; Sat, 21 Nov 2020 11:40:32 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Sat, 21 Nov 2020 11:40:32 +0000 From: Marc Zyngier To: Nick Desaulniers Cc: Ard Biesheuvel , linux-arch , Alistair Delva , Kees Cook , "Paul E. McKenney" , Kernel Hardening , Peter Zijlstra , Greg Kroah-Hartman , Masahiro Yamada , Linux Kbuild mailing list , PCI , LKML , Steven Rostedt , clang-built-linux , Sami Tolvanen , Josh Poimboeuf , Will Deacon , Linux ARM Subject: Re: [PATCH v7 00/17] Add support for Clang LTO In-Reply-To: References: <20201118220731.925424-1-samitolvanen@google.com> User-Agent: Roundcube Webmail/1.4.9 Message-ID: X-Sender: maz@misterjones.org X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: ndesaulniers@google.com, ardb@kernel.org, linux-arch@vger.kernel.org, adelva@google.com, keescook@chromium.org, paulmck@kernel.org, kernel-hardening@lists.openwall.com, peterz@infradead.org, gregkh@linuxfoundation.org, masahiroy@kernel.org, linux-kbuild@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, rostedt@goodmis.org, clang-built-linux@googlegroups.com, samitolvanen@google.com, jpoimboe@redhat.com, will@kernel.org, linux-arm-kernel@lists.infradead.org X-SA-Exim-Mail-From: maz@misterjones.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org On 2020-11-20 23:53, Nick Desaulniers wrote: > On Fri, Nov 20, 2020 at 3:30 PM Ard Biesheuvel wrote: >> >> On Fri, 20 Nov 2020 at 21:19, Nick Desaulniers >> wrote: >> > >> > On Fri, Nov 20, 2020 at 2:30 AM Ard Biesheuvel wrote: >> > > >> > > On Thu, 19 Nov 2020 at 00:42, Nick Desaulniers wrote: >> > > > >> > > > Thanks for continuing to drive this series Sami. For the series, >> > > > >> > > > Tested-by: Nick Desaulniers >> > > > >> > > > I did virtualized boot tests with the series applied to aarch64 >> > > > defconfig without CONFIG_LTO, with CONFIG_LTO_CLANG, and a third time >> > > > with CONFIG_THINLTO. If you make changes to the series in follow ups, >> > > > please drop my tested by tag from the modified patches and I'll help >> > > > re-test. Some minor feedback on the Kconfig change, but I'll post it >> > > > off of that patch. >> > > > >> > > >> > > When you say 'virtualized" do you mean QEMU on x86? Or actual >> > > virtualization on an AArch64 KVM host? >> > >> > aarch64 guest on x86_64 host. If you have additional configurations >> > that are important to you, additional testing help would be >> > appreciated. >> > >> >> Could you run this on an actual phone? Or does Android already ship >> with this stuff? > > By `this`, if you mean "the LTO series", it has been shipping on > Android phones for years now, I think it's even required in the latest > release. > > If you mean "the LTO series + mainline" on a phone, well there's the > android-mainline of https://android.googlesource.com/kernel/common/, > in which this series was recently removed in order to facilitate > rebasing Android's patches on ToT-mainline until getting the series > landed upstream. Bit of a chicken and the egg problem there. > > If you mean "the LTO series + mainline + KVM" on a phone; I don't know > the precise state of aarch64 KVM and Android (Will or Marc would > know). If you are lucky enough to have an Android system booting at EL2, KVM should just works [1], though I haven't tried with this series. > We did experiment recently with RockPI's for aach64 KVM, IIRC; > I think Android is tricky as it still requires A64+A32/T32 chipsets, Which is about 100% of the Android systems at the moment (I don't think any of the asymmetric SoCs are in the wild yet). It doesn't really affect KVM anyway. M. [1] with the broken firmware gotchas that I believed to be erradicated 8 years ago, but are still prevalent in the Android world: laughable PSCI implementation, invalid CNTFRQ_EL0... -- Who you jivin' with that Cosmik Debris?