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=-14.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,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 5D462C49EA6 for ; Thu, 24 Jun 2021 10:43:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3F48D61400 for ; Thu, 24 Jun 2021 10:43:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232230AbhFXKpo (ORCPT ); Thu, 24 Jun 2021 06:45:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:59084 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232213AbhFXKpl (ORCPT ); Thu, 24 Jun 2021 06:45:41 -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 45619613FD; Thu, 24 Jun 2021 10:43:22 +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 1lwMpM-009Zh2-CA; Thu, 24 Jun 2021 11:43:20 +0100 Date: Thu, 24 Jun 2021 11:43:19 +0100 Message-ID: <87lf6zilvc.wl-maz@kernel.org> From: Marc Zyngier To: David Stevens Cc: Huacai Chen , Aleksandar Markovic , Paul Mackerras , Paolo Bonzini , Zhenyu Wang , Zhi Wang , James Morse , Alexandru Elisei , Suzuki K Poulose , Will Deacon , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, intel-gvt-dev@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Subject: Re: [PATCH 4/6] KVM: arm64/mmu: avoid struct page in MMU In-Reply-To: <20210624035749.4054934-5-stevensd@google.com> References: <20210624035749.4054934-1-stevensd@google.com> <20210624035749.4054934-5-stevensd@google.com> 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: stevensd@chromium.org, chenhuacai@kernel.org, aleksandar.qemu.devel@gmail.com, paulus@ozlabs.org, pbonzini@redhat.com, zhenyuw@linux.intel.com, zhi.a.wang@intel.com, james.morse@arm.com, alexandru.elisei@arm.com, suzuki.poulose@arm.com, will@kernel.org, seanjc@google.com, vkuznets@redhat.com, wanpengli@tencent.com, jmattson@google.com, joro@8bytes.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, intel-gvt-dev@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.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, 24 Jun 2021 04:57:47 +0100, David Stevens wrote: > > From: David Stevens > > Avoid converting pfns returned by follow_fault_pfn to struct pages to > transiently take a reference. The reference was originally taken to > match the reference taken by gup. However, pfns returned by > follow_fault_pfn may not have a struct page set up for reference > counting. > > Signed-off-by: David Stevens > --- > arch/arm64/kvm/mmu.c | 43 +++++++++++++++++++++++-------------------- > 1 file changed, 23 insertions(+), 20 deletions(-) > > diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c > index 896b3644b36f..a741972cb75f 100644 > --- a/arch/arm64/kvm/mmu.c > +++ b/arch/arm64/kvm/mmu.c [...] > @@ -968,16 +968,16 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, > */ > if (vma_pagesize == PAGE_SIZE && !force_pte) > vma_pagesize = transparent_hugepage_adjust(memslot, hva, > - &pfn, &fault_ipa); > + &pfnpg, &fault_ipa); > if (writable) > prot |= KVM_PGTABLE_PROT_W; > > if (fault_status != FSC_PERM && !device) > - clean_dcache_guest_page(pfn, vma_pagesize); > + clean_dcache_guest_page(pfnpg.pfn, vma_pagesize); > > if (exec_fault) { > prot |= KVM_PGTABLE_PROT_X; > - invalidate_icache_guest_page(pfn, vma_pagesize); > + invalidate_icache_guest_page(pfnpg.pfn, vma_pagesize); This is going to clash with what is currently in -next, specially with MTE. Paolo, if you really want to take this in 5.13, can you please push a stable branch based on -rc4 or older so that I can merge it in and test it? Thanks, M. -- Without deviation from the norm, progress is not possible.