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 3C5E0C433FE for ; Fri, 11 Nov 2022 16:54:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234195AbiKKQyV (ORCPT ); Fri, 11 Nov 2022 11:54:21 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41930 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234175AbiKKQyU (ORCPT ); Fri, 11 Nov 2022 11:54:20 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F0B71716C9 for ; Fri, 11 Nov 2022 08:54:17 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 7F35B6205A for ; Fri, 11 Nov 2022 16:54:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D50DDC433D7; Fri, 11 Nov 2022 16:54:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1668185656; bh=V/4r+ljPjRP3kyOGZMiUj9fZdU5kQWc0BerI3B4lM74=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=OEp3VPeo/Dc5lHgnCZGsftYiePdL0Z503ga2WED+orMdhlpaJjYNwVOf8/YDNn1je UUSuHz6XvbMIQOsslEqhyHp6qG29WxrNGb3UOSCcQwe6PTTkz9vwLRySagfzNiJiLO W5eTU2maM6z2Mz0bv3SY2ekiGlt7HAYjXTb7WiE4+4RBHLCQOacbZEpE1NQf7VMkxk B4jsksLjr+DjNUUAiDLFDTME8J7DxdVPVHeV4EUkZot6su8HdgGVvJrr2Pwwd/8lr7 EAy1MnmnPjeKOjvJU1Osutjtdh/UTFsaARDp/VBmVqTAVzDR1iEUjNAxLpkyzQnqxU qVB3cpwU8GBZw== Received: from sofa.misterjones.org ([185.219.108.64] helo=goblin-girl.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1otXIE-005TOg-LT; Fri, 11 Nov 2022 16:54:14 +0000 Date: Fri, 11 Nov 2022 16:54:14 +0000 Message-ID: <86edu9ph3d.wl-maz@kernel.org> From: Marc Zyngier To: Will Deacon Cc: kvmarm@lists.linux.dev, Sean Christopherson , Vincent Donnefort , Alexandru Elisei , Catalin Marinas , Philippe =?UTF-8?B?TWF0aGlldS1EYXVkw6k=?= , James Morse , Chao Peng , Quentin Perret , Suzuki K Poulose , Mark Rutland , Fuad Tabba , Oliver Upton , kernel-team@android.com, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v6 00/26] KVM: arm64: Introduce pKVM hyp VM and vCPU state at EL2 In-Reply-To: <20221110190259.26861-1-will@kernel.org> References: <20221110190259.26861-1-will@kernel.org> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: will@kernel.org, kvmarm@lists.linux.dev, seanjc@google.com, vdonnefort@google.com, alexandru.elisei@arm.com, catalin.marinas@arm.com, philmd@linaro.org, james.morse@arm.com, chao.p.peng@linux.intel.com, qperret@google.com, suzuki.poulose@arm.com, mark.rutland@arm.com, tabba@google.com, oliver.upton@linux.dev, kernel-team@android.com, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Thu, 10 Nov 2022 19:02:33 +0000, Will Deacon wrote: > > Hi all, > > This is version six of the pKVM EL2 state series, extending the pKVM > hypervisor code so that it can dynamically instantiate and manage VM > data structures without the host being able to access them directly. > These structures consist of a hyp VM, a set of hyp vCPUs and the stage-2 > page-table for the MMU. The pages used to hold the hypervisor structures > are returned to the host when the VM is destroyed. > > Previous versions are archived at: > > Mega-patch: https://lore.kernel.org/kvmarm/20220519134204.5379-1-will@kernel.org/ > v2: https://lore.kernel.org/all/20220630135747.26983-1-will@kernel.org/ > v3: https://lore.kernel.org/kvmarm/20220914083500.5118-1-will@kernel.org/ > v4: https://lore.kernel.org/kvm/20221017115209.2099-1-will@kernel.org/ > v5: https://lore.kernel.org/r/20221020133827.5541-1-will@kernel.org > > The changes since v5 include: > > * Fix teardown ordering so that the host 'kvm' structure remains pins > while the memcache is being filled. > > * Fixed a kerneldoc typo. > > * Included a patch from Oliver to rework the 'pkvm_mem_transition' > structure and it's handling of the completer address. > > * Tweaked some commit messages and added new R-b tags. > > As before, the final patch is RFC since it illustrates a very naive use > of the new hypervisor structures and subsequent changes will improve on > this once we have the guest private memory story sorted out. > > Oliver: I'm pretty sure we're going to need to revert your completer > address cleanup as soon as we have guest-host sharing. We want to keep > the 'pkvm_mem_transition' structure 'const', but we will only know the > host address (PA) after walking the guest stage-2 and so we're going to > want to track that separately. Anyway, I've included it here at the end > so Marc can decide what he wants to do! Thanks, I guess... :-/ If this patch is going to be reverted, I'd rather not take it (without guest/host sharing, we don't have much of a hypervisor). I guess we can always revisit this in the light of the avalanche of pKVM patches that will follow... Cheers, M. -- Without deviation from the norm, progress is not possible.