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 38330C433EF for ; Mon, 29 Nov 2021 20:07:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231905AbhK2UKu (ORCPT ); Mon, 29 Nov 2021 15:10:50 -0500 Received: from sin.source.kernel.org ([145.40.73.55]:50198 "EHLO sin.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348333AbhK2UIs (ORCPT ); Mon, 29 Nov 2021 15:08:48 -0500 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 sin.source.kernel.org (Postfix) with ESMTPS id 5A8D9CE13DF for ; Mon, 29 Nov 2021 20:05:29 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 83125C53FCD; Mon, 29 Nov 2021 20:05:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1638216327; bh=2ThkwV02KLfELC/usIrKEsYVmRRm/yHVr4F9Cx+Dngw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=G0uH7D1z0AFrAjWMCNMBiB7zMbl+T0kAkO07VKHKPSVBx5qmHNHAga3ggCW3vBCr1 YuFMMLXcJatV32Y+2Xxx8INGb3vHG91VUDPBQpf+Gq/pAlaYFuyRQ1nI6ex5H/wQj2 8mRm6LpeXQ22opHOZ31qz9CCf4uYF/eGf5c+yv83SdYQwLhAZmlI7Z4RFA/IADoc05 0NvkaK/XmLg/DI2C7OLwDB5ZPgT+iYkz910fmk4xuxrn5NuAIVYWKiwxRssVOuUOye VIWHX6XCpNQEkESiD6wHrpmEjDa/Lfh/damAI3goQUkbSagJqCE8m5OGJGdINV7b23 yIad/gVFy8KyA== Received: from sofa.misterjones.org ([185.219.108.64] helo=why.lan) 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 1mrmr0-008gvR-J1; Mon, 29 Nov 2021 20:02:22 +0000 From: Marc Zyngier To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Cc: Andre Przywara , Christoffer Dall , Jintack Lim , Haibo Xu , Ganapatrao Kulkarni , James Morse , Suzuki K Poulose , Alexandru Elisei , kernel-team@android.com Subject: [PATCH v5 41/69] KVM: arm64: nv: Restrict S2 RD/WR permissions to match the guest's Date: Mon, 29 Nov 2021 20:01:22 +0000 Message-Id: <20211129200150.351436-42-maz@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20211129200150.351436-1-maz@kernel.org> References: <20211129200150.351436-1-maz@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, andre.przywara@arm.com, christoffer.dall@arm.com, jintack@cs.columbia.edu, haibo.xu@linaro.org, gankulkarni@os.amperecomputing.com, james.morse@arm.com, suzuki.poulose@arm.com, alexandru.elisei@arm.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: kvm@vger.kernel.org When mapping a page in a shadow stage-2, special care must be taken not to be more permissive than the guest is (writable or readable page when the guest hasn't set that permission). Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/kvm_nested.h | 15 +++++++++++++++ arch/arm64/kvm/mmu.c | 14 +++++++++++++- arch/arm64/kvm/nested.c | 2 +- 3 files changed, 29 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/kvm_nested.h b/arch/arm64/include/asm/kvm_nested.h index 4f93a5dab183..3f3d8e10bd99 100644 --- a/arch/arm64/include/asm/kvm_nested.h +++ b/arch/arm64/include/asm/kvm_nested.h @@ -93,6 +93,21 @@ static inline u32 kvm_s2_trans_esr(struct kvm_s2_trans *trans) return trans->esr; } +static inline bool kvm_s2_trans_readable(struct kvm_s2_trans *trans) +{ + return trans->readable; +} + +static inline bool kvm_s2_trans_writable(struct kvm_s2_trans *trans) +{ + return trans->writable; +} + +static inline bool kvm_s2_trans_executable(struct kvm_s2_trans *trans) +{ + return !(trans->upper_attr & BIT(54)); +} + extern int kvm_walk_nested_s2(struct kvm_vcpu *vcpu, phys_addr_t gipa, struct kvm_s2_trans *result); diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index fc3613d3f503..d63f60f95abc 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -1123,6 +1123,17 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, if (exec_fault && device) return -ENOEXEC; + /* + * Potentially reduce shadow S2 permissions to match the guest's own + * S2. For exec faults, we'd only reach this point if the guest + * actually allowed it (see kvm_s2_handle_perm_fault). + */ + if (kvm_is_shadow_s2_fault(vcpu)) { + writable &= kvm_s2_trans_writable(nested); + if (!kvm_s2_trans_readable(nested)) + prot &= ~KVM_PGTABLE_PROT_R; + } + spin_lock(&kvm->mmu_lock); pgt = vcpu->arch.hw_mmu->pgt; if (mmu_notifier_retry(kvm, mmu_seq)) @@ -1161,7 +1172,8 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, if (device) prot |= KVM_PGTABLE_PROT_DEVICE; - else if (cpus_have_const_cap(ARM64_HAS_CACHE_DIC)) + else if (cpus_have_const_cap(ARM64_HAS_CACHE_DIC) && + kvm_s2_trans_executable(nested)) prot |= KVM_PGTABLE_PROT_X; /* diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c index c34e96955e04..fb748f2b9e87 100644 --- a/arch/arm64/kvm/nested.c +++ b/arch/arm64/kvm/nested.c @@ -493,7 +493,7 @@ int kvm_s2_handle_perm_fault(struct kvm_vcpu *vcpu, struct kvm_s2_trans *trans) return 0; if (kvm_vcpu_trap_is_iabt(vcpu)) { - forward_fault = (trans->upper_attr & BIT(54)); + forward_fault = !kvm_s2_trans_executable(trans); } else { bool write_fault = kvm_is_write_fault(vcpu); -- 2.30.2