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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,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 1F5C5C4338F for ; Wed, 11 Aug 2021 04:51:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E905560C40 for ; Wed, 11 Aug 2021 04:51:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233885AbhHKEwU (ORCPT ); Wed, 11 Aug 2021 00:52:20 -0400 Received: from foss.arm.com ([217.140.110.172]:42414 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233729AbhHKEwS (ORCPT ); Wed, 11 Aug 2021 00:52:18 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6E0E66D; Tue, 10 Aug 2021 21:51:55 -0700 (PDT) Received: from p8cg001049571a15.arm.com (unknown [10.163.67.241]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id B1BF13F40C; Tue, 10 Aug 2021 21:51:51 -0700 (PDT) From: Anshuman Khandual To: linux-arm-kernel@lists.infradead.org Cc: mark.rutland@arm.com, Anshuman Khandual , Marc Zyngier , James Morse , Alexandru Elisei , Suzuki K Poulose , Catalin Marinas , Will Deacon , kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org Subject: [PATCH] KVM: arm64: Restrict IPA size to maximum 48 bits on 4K and 16K page size Date: Wed, 11 Aug 2021 10:22:29 +0530 Message-Id: <1628657549-27584-1-git-send-email-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.7.4 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Even though ID_AA64MMFR0.PARANGE reports 52 bit PA size support, it cannot be enabled as guest IPA size on 4K or 16K page size configurations. Hence kvm_ipa_limit must be restricted to 48 bits. This change achieves required IPA capping. Before the commit c9b69a0cf0b4 ("KVM: arm64: Don't constrain maximum IPA size based on host configuration"), the problem here would have been just latent via PHYS_MASK_SHIFT (which earlier in turn capped kvm_ipa_limit), which remains capped at 48 bits on 4K and 16K configs. Cc: Marc Zyngier Cc: James Morse Cc: Alexandru Elisei Cc: Suzuki K Poulose Cc: Catalin Marinas Cc: Will Deacon Cc: linux-arm-kernel@lists.infradead.org Cc: kvmarm@lists.cs.columbia.edu Cc: linux-kernel@vger.kernel.org Fixes: c9b69a0cf0b4 ("KVM: arm64: Don't constrain maximum IPA size based on host configuration") Signed-off-by: Anshuman Khandual --- This applies on v5.14-rc5 arch/arm64/kvm/reset.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c index 20588220fe66..e66974c4b9d3 100644 --- a/arch/arm64/kvm/reset.c +++ b/arch/arm64/kvm/reset.c @@ -337,6 +337,15 @@ int kvm_set_ipa_limit(void) return -EINVAL; } + /* + * IPA size beyond 48 bits could not be supported + * on either 4K or 16K page size. Hence let's cap + * it to 48 bits, in case it's reported as larger + * on the system. + */ + if (!IS_ENABLED(CONFIG_ARM64_64K_PAGES)) + parange = min(parange, (unsigned int)ID_AA64MMFR0_PARANGE_48); + kvm_ipa_limit = id_aa64mmfr0_parange_to_phys_shift(parange); kvm_info("IPA Size Limit: %d bits%s\n", kvm_ipa_limit, ((kvm_ipa_limit < KVM_PHYS_SHIFT) ? -- 2.20.1