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=-9.0 required=3.0 tests=BAYES_00,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 611ADC4338F for ; Mon, 26 Jul 2021 13:24:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 400BB60F58 for ; Mon, 26 Jul 2021 13:24:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233456AbhGZMoS (ORCPT ); Mon, 26 Jul 2021 08:44:18 -0400 Received: from mail.kernel.org ([198.145.29.99]:55664 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232572AbhGZMoR (ORCPT ); Mon, 26 Jul 2021 08:44:17 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (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 DAB596056C; Mon, 26 Jul 2021 13:24:45 +0000 (UTC) Received: from sofa.misterjones.org ([185.219.108.64] helo=why.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1m80b5-0012pR-Te; Mon, 26 Jul 2021 14:24:43 +0100 Date: Mon, 26 Jul 2021 14:24:43 +0100 Message-ID: <87mtq9dx7o.wl-maz@kernel.org> From: Marc Zyngier To: Quentin Perret Cc: james.morse@arm.com, alexandru.elisei@arm.com, suzuki.poulose@arm.com, catalin.marinas@arm.com, will@kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, ardb@kernel.org, qwandor@google.com, tabba@google.com, dbrazdil@google.com, kernel-team@android.com Subject: Re: [PATCH v2 04/16] KVM: arm64: Optimize host memory aborts In-Reply-To: References: <20210726092905.2198501-1-qperret@google.com> <20210726092905.2198501-5-qperret@google.com> <87pmv5e529.wl-maz@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 (x86_64-pc-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: qperret@google.com, james.morse@arm.com, alexandru.elisei@arm.com, suzuki.poulose@arm.com, catalin.marinas@arm.com, will@kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, ardb@kernel.org, qwandor@google.com, tabba@google.com, dbrazdil@google.com, kernel-team@android.com 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: linux-kernel@vger.kernel.org On Mon, 26 Jul 2021 14:13:06 +0100, Quentin Perret wrote: > > On Monday 26 Jul 2021 at 11:35:10 (+0100), Marc Zyngier wrote: [...] > > You could also use a kvm_mem_range for the iteration, and add a helper > > that checks for the inclusion. > > Something like this (untested)? > > diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c > index 75273166d2c5..07d228163090 100644 > --- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c > +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c > @@ -234,9 +234,15 @@ static inline int __host_stage2_idmap(u64 start, u64 end, > __ret; \ > }) > > +static inline bool range_included(struct kvm_mem_range *child, > + struct kvm_mem_range *parent) > +{ > + return parent->start <= child->start && child->end <= parent->end; > +} > + > static int host_stage2_find_range(u64 addr, struct kvm_mem_range *range) > { > - u64 granule, start, end; > + struct kvm_mem_range cur; > kvm_pte_t pte; > u32 level; > int ret; > @@ -252,16 +258,15 @@ static int host_stage2_find_range(u64 addr, struct kvm_mem_range *range) > return -EPERM; > > do { > - granule = kvm_granule_size(level); > - start = ALIGN_DOWN(addr, granule); > - end = start + granule; > + u64 granule = kvm_granule_size(level); > + cur.start = ALIGN_DOWN(addr, granule); > + cur.end = cur.start + granule; > level++; > } while ((level < KVM_PGTABLE_MAX_LEVELS) && > - (!kvm_level_supports_block_mapping(level) || > - start < range->start || range->end < end)); > + !(kvm_level_supports_block_mapping(level) && > + range_included(&cur, parent))); > > - range->start = start; > - range->end = end; > + *range = cur; > > return 0; > } > Beautiful. M. -- Without deviation from the norm, progress is not possible.