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=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 B9C7EC43382 for ; Wed, 26 Sep 2018 16:34:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7EA3721536 for ; Wed, 26 Sep 2018 16:34:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7EA3721536 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729051AbeIZWsA (ORCPT ); Wed, 26 Sep 2018 18:48:00 -0400 Received: from foss.arm.com ([217.140.101.70]:50164 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728554AbeIZWsA (ORCPT ); Wed, 26 Sep 2018 18:48:00 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A32641684; Wed, 26 Sep 2018 09:34:14 -0700 (PDT) Received: from en101.Emea.Arm.com (en101.emea.arm.com [10.4.13.23]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 2AE933F5B3; Wed, 26 Sep 2018 09:34:12 -0700 (PDT) From: Suzuki K Poulose To: linux-arm-kernel@lists.infradead.org Cc: kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, marc.zyngier@arm.com, cdall@kernel.org, eric.auger@redhat.com, suzuki.poulose@arm.com, will.deacon@arm.com, dave.martin@arm.com, peter.maydell@linaro.org, pbonzini@redhat.com, rkrcmar@redhat.com, julien.grall@arm.com, linux-kernel@vger.kernel.org Subject: [PATCH v6 17/18] kvm: arm64: Limit the minimum number of page table levels Date: Wed, 26 Sep 2018 17:32:53 +0100 Message-Id: <20180926163258.20218-18-suzuki.poulose@arm.com> X-Mailer: git-send-email 2.19.0 In-Reply-To: <20180926163258.20218-1-suzuki.poulose@arm.com> References: <20180926163258.20218-1-suzuki.poulose@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Since we are about to remove the lower limit on the IPA size, make sure that we do not go to 1 level page table (e.g, with 32bit IPA on 64K host with concatenation) to avoid splitting the host PMD huge pages at stage2. Cc: Marc Zyngier Cc: Christoffer Dall Signed-off-by: Suzuki K Poulose --- Change since v5: - Cosmetic changes to the comment - Remove unnecessary new line --- arch/arm64/include/asm/stage2_pgtable.h | 7 ++++++- arch/arm64/kvm/reset.c | 10 +++++++++- 2 files changed, 15 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/stage2_pgtable.h b/arch/arm64/include/asm/stage2_pgtable.h index c62fe118a898..2cce769ba4c6 100644 --- a/arch/arm64/include/asm/stage2_pgtable.h +++ b/arch/arm64/include/asm/stage2_pgtable.h @@ -72,8 +72,13 @@ /* * The number of PTRS across all concatenated stage2 tables given by the * number of bits resolved at the initial level. + * If we force more levels than necessary, we may have (stage2_pgdir_shift > IPA), + * in which case, stage2_pgd_ptrs will have one entry. */ -#define __s2_pgd_ptrs(ipa, lvls) (1 << ((ipa) - pt_levels_pgdir_shift((lvls)))) +#define pgd_ptrs_shift(ipa, pgdir_shift) \ + ((ipa) > (pgdir_shift) ? ((ipa) - (pgdir_shift)) : 0) +#define __s2_pgd_ptrs(ipa, lvls) \ + (1 << (pgd_ptrs_shift((ipa), pt_levels_pgdir_shift(lvls)))) #define __s2_pgd_size(ipa, lvls) (__s2_pgd_ptrs((ipa), (lvls)) * sizeof(pgd_t)) #define stage2_pgd_ptrs(kvm) __s2_pgd_ptrs(kvm_phys_shift(kvm), kvm_stage2_levels(kvm)) diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c index 96b3f50101bc..f156e45760bc 100644 --- a/arch/arm64/kvm/reset.c +++ b/arch/arm64/kvm/reset.c @@ -190,6 +190,7 @@ int kvm_arm_config_vm(struct kvm *kvm, unsigned long type) { u64 vtcr = VTCR_EL2_FLAGS; u32 parange, phys_shift; + u8 lvls; if (type) return -EINVAL; @@ -203,7 +204,14 @@ int kvm_arm_config_vm(struct kvm *kvm, unsigned long type) if (phys_shift > KVM_PHYS_SHIFT) phys_shift = KVM_PHYS_SHIFT; vtcr |= VTCR_EL2_T0SZ(phys_shift); - vtcr |= VTCR_EL2_LVLS_TO_SL0(stage2_pgtable_levels(phys_shift)); + /* + * Use a minimum 2 level page table to prevent splitting + * host PMD huge pages at stage2. + */ + lvls = stage2_pgtable_levels(phys_shift); + if (lvls < 2) + lvls = 2; + vtcr |= VTCR_EL2_LVLS_TO_SL0(lvls); /* * Enable the Hardware Access Flag management, unconditionally -- 2.19.0