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 10405C43217 for ; Mon, 17 Oct 2022 11:52:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230170AbiJQLwk (ORCPT ); Mon, 17 Oct 2022 07:52:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59694 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230118AbiJQLwi (ORCPT ); Mon, 17 Oct 2022 07:52:38 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 878E221269 for ; Mon, 17 Oct 2022 04:52:37 -0700 (PDT) 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 228A36108F for ; Mon, 17 Oct 2022 11:52:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 81290C43470; Mon, 17 Oct 2022 11:52:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1666007556; bh=XLQqaxaFoJ1w3bEHfz1Nz6Iwt6VUcQunxS4ndTgHiAM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OtwOuGSPZNKY1wGsGfTC3CdnUYjAJ9W9W9jQejtnn1OqdAFely9JX6+eODDmVgjo8 eDZK0WBd84y8+B+E+7yKsphgi8eoMsloZ5yJ/MxOrWBmaMIm+EE0tdUHtVju342P6z XftVm65y1W9qjkUUqI8E8iehET+o6mLXNtPQeU/rgY9htflfcYjq6giijFLOHb0JjU XsyTlMz8d3+dcUY+DieJvk75+ahwqL7PZzn8YpCGJ7+YWFCEcX/Xg/RDij7CRwDRDj Fvm5iidxbCWz7XJrKHMiaeRKwlaTwIJnPVE1djDNYRR7za2ex8pi/gpz4C2o0kXHyY GCtWO5FgIQu0w== From: Will Deacon To: kvmarm@lists.linux.dev Cc: Will Deacon , Sean Christopherson , Vincent Donnefort , Alexandru Elisei , Catalin Marinas , James Morse , Chao Peng , Quentin Perret , Suzuki K Poulose , Mark Rutland , Fuad Tabba , Oliver Upton , Marc Zyngier , kernel-team@android.com, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH v4 04/25] KVM: arm64: Fix-up hyp stage-1 refcounts for all pages mapped at EL2 Date: Mon, 17 Oct 2022 12:51:48 +0100 Message-Id: <20221017115209.2099-5-will@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20221017115209.2099-1-will@kernel.org> References: <20221017115209.2099-1-will@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Quentin Perret In order to allow unmapping arbitrary memory pages from the hypervisor stage-1 page-table, fix-up the initial refcount for pages that have been mapped before the 'vmemmap' array was up and running so that it accurately accounts for all existing hypervisor mappings. This is achieved by traversing the entire hypervisor stage-1 page-table during initialisation of EL2 and updating the corresponding 'struct hyp_page' for each valid mapping. Tested-by: Vincent Donnefort Signed-off-by: Quentin Perret Signed-off-by: Will Deacon --- arch/arm64/kvm/hyp/nvhe/setup.c | 62 +++++++++++++++++++++++---------- 1 file changed, 43 insertions(+), 19 deletions(-) diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c index 579eb4f73476..8f2726d7e201 100644 --- a/arch/arm64/kvm/hyp/nvhe/setup.c +++ b/arch/arm64/kvm/hyp/nvhe/setup.c @@ -185,12 +185,11 @@ static void hpool_put_page(void *addr) hyp_put_page(&hpool, addr); } -static int finalize_host_mappings_walker(u64 addr, u64 end, u32 level, - kvm_pte_t *ptep, - enum kvm_pgtable_walk_flags flag, - void * const arg) +static int fix_host_ownership_walker(u64 addr, u64 end, u32 level, + kvm_pte_t *ptep, + enum kvm_pgtable_walk_flags flag, + void * const arg) { - struct kvm_pgtable_mm_ops *mm_ops = arg; enum kvm_pgtable_prot prot; enum pkvm_page_state state; kvm_pte_t pte = *ptep; @@ -199,15 +198,6 @@ static int finalize_host_mappings_walker(u64 addr, u64 end, u32 level, if (!kvm_pte_valid(pte)) return 0; - /* - * Fix-up the refcount for the page-table pages as the early allocator - * was unable to access the hyp_vmemmap and so the buddy allocator has - * initialised the refcount to '1'. - */ - mm_ops->get_page(ptep); - if (flag != KVM_PGTABLE_WALK_LEAF) - return 0; - if (level != (KVM_PGTABLE_MAX_LEVELS - 1)) return -EINVAL; @@ -236,12 +226,30 @@ static int finalize_host_mappings_walker(u64 addr, u64 end, u32 level, return host_stage2_idmap_locked(phys, PAGE_SIZE, prot); } -static int finalize_host_mappings(void) +static int fix_hyp_pgtable_refcnt_walker(u64 addr, u64 end, u32 level, + kvm_pte_t *ptep, + enum kvm_pgtable_walk_flags flag, + void * const arg) +{ + struct kvm_pgtable_mm_ops *mm_ops = arg; + kvm_pte_t pte = *ptep; + + /* + * Fix-up the refcount for the page-table pages as the early allocator + * was unable to access the hyp_vmemmap and so the buddy allocator has + * initialised the refcount to '1'. + */ + if (kvm_pte_valid(pte)) + mm_ops->get_page(ptep); + + return 0; +} + +static int fix_host_ownership(void) { struct kvm_pgtable_walker walker = { - .cb = finalize_host_mappings_walker, - .flags = KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_TABLE_POST, - .arg = pkvm_pgtable.mm_ops, + .cb = fix_host_ownership_walker, + .flags = KVM_PGTABLE_WALK_LEAF, }; int i, ret; @@ -257,6 +265,18 @@ static int finalize_host_mappings(void) return 0; } +static int fix_hyp_pgtable_refcnt(void) +{ + struct kvm_pgtable_walker walker = { + .cb = fix_hyp_pgtable_refcnt_walker, + .flags = KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_TABLE_POST, + .arg = pkvm_pgtable.mm_ops, + }; + + return kvm_pgtable_walk(&pkvm_pgtable, 0, BIT(pkvm_pgtable.ia_bits), + &walker); +} + void __noreturn __pkvm_init_finalise(void) { struct kvm_host_data *host_data = this_cpu_ptr(&kvm_host_data); @@ -286,7 +306,11 @@ void __noreturn __pkvm_init_finalise(void) }; pkvm_pgtable.mm_ops = &pkvm_pgtable_mm_ops; - ret = finalize_host_mappings(); + ret = fix_host_ownership(); + if (ret) + goto out; + + ret = fix_hyp_pgtable_refcnt(); if (ret) goto out; -- 2.38.0.413.g74048e4d9e-goog