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 mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by smtp.lore.kernel.org (Postfix) with ESMTP id CF461C43334 for ; Thu, 30 Jun 2022 13:58:34 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 7B20A4B3D9; Thu, 30 Jun 2022 09:58:34 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Authentication-Results: mm01.cs.columbia.edu (amavisd-new); dkim=softfail (fail, message has been altered) header.i=@kernel.org Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id xgAWb0tV5uHY; Thu, 30 Jun 2022 09:58:32 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 161324B4D4; Thu, 30 Jun 2022 09:58:32 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 24C3540712 for ; Thu, 30 Jun 2022 09:58:31 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id tvcabM2mAaRj for ; Thu, 30 Jun 2022 09:58:29 -0400 (EDT) Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id C4ED841175 for ; Thu, 30 Jun 2022 09:58:29 -0400 (EDT) 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 ams.source.kernel.org (Postfix) with ESMTPS id 045BAB82AEF; Thu, 30 Jun 2022 13:58:29 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 66962C34115; Thu, 30 Jun 2022 13:58:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1656597507; bh=vQhtWqNapQ5J/g7Q7VK4YV9y0KdMgU3VBqeX83rHXNI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SoEKnFL3hgkDfN/MGe8myg97zESuSdsnvp9F8LErpnaS1LVdLuod7/7AZfVX6OAdI l0piGZBd7Q2oPlR3d3a4sSflQpEnoPYgox6Q+kWqjBsjiGqXVxOCNTvqzii+uKF5HU pT6IUoEKKNH/0eNM2XYE/V6Bzs85DiNNNKDnIroz/Fu8rOevTdiEKrrnaLDbFnosbD lpL3mKpMYjbw5Bje8W1lt8X/ZkR8wKJHkoVuMKgxWORQzB4XeHkG/YJWaNECBQ9CYM cpuWeC+yCZLi1PBmDw57lP21NWAbXX/sIdRC8BkHsA+efxKwWzVFMADP2Rb+OCoXWf Cn3x8CEqoCGDQ== From: Will Deacon To: kvmarm@lists.cs.columbia.edu Subject: [PATCH v2 08/24] KVM: arm64: Prevent the donation of no-map pages Date: Thu, 30 Jun 2022 14:57:31 +0100 Message-Id: <20220630135747.26983-9-will@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20220630135747.26983-1-will@kernel.org> References: <20220630135747.26983-1-will@kernel.org> MIME-Version: 1.0 Cc: Marc Zyngier , kernel-team@android.com, kvm@vger.kernel.org, Andy Lutomirski , linux-arm-kernel@lists.infradead.org, Michael Roth , Catalin Marinas , Chao Peng , Will Deacon X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu From: Quentin Perret Memory regions marked as no-map in DT routinely include TrustZone carevouts and such. Although donating such pages to the hypervisor may not breach confidentiality, it may be used to corrupt its state in uncontrollable ways. To prevent this, let's block host-initiated memory transitions targeting no-map pages altogether in nVHE protected mode as there should be no valid reason to do this currently. Thankfully, the pKVM EL2 hypervisor has a full copy of the host's list of memblock regions, hence allowing to check for the presence of the MEMBLOCK_NOMAP flag on any given region at EL2 easily. Signed-off-by: Quentin Perret Signed-off-by: Will Deacon --- arch/arm64/kvm/hyp/nvhe/mem_protect.c | 22 ++++++++++++++++------ 1 file changed, 16 insertions(+), 6 deletions(-) diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c index f475d554c9fd..e7015bbefbea 100644 --- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c @@ -193,7 +193,7 @@ struct kvm_mem_range { u64 end; }; -static bool find_mem_range(phys_addr_t addr, struct kvm_mem_range *range) +static struct memblock_region *find_mem_range(phys_addr_t addr, struct kvm_mem_range *range) { int cur, left = 0, right = hyp_memblock_nr; struct memblock_region *reg; @@ -216,18 +216,28 @@ static bool find_mem_range(phys_addr_t addr, struct kvm_mem_range *range) } else { range->start = reg->base; range->end = end; - return true; + return reg; } } - return false; + return NULL; } bool addr_is_memory(phys_addr_t phys) { struct kvm_mem_range range; - return find_mem_range(phys, &range); + return !!find_mem_range(phys, &range); +} + +static bool addr_is_allowed_memory(phys_addr_t phys) +{ + struct memblock_region *reg; + struct kvm_mem_range range; + + reg = find_mem_range(phys, &range); + + return reg && !(reg->flags & MEMBLOCK_NOMAP); } static bool is_in_mem_range(u64 addr, struct kvm_mem_range *range) @@ -350,7 +360,7 @@ static bool host_stage2_force_pte_cb(u64 addr, u64 end, enum kvm_pgtable_prot pr static int host_stage2_idmap(u64 addr) { struct kvm_mem_range range; - bool is_memory = find_mem_range(addr, &range); + bool is_memory = !!find_mem_range(addr, &range); enum kvm_pgtable_prot prot; int ret; @@ -428,7 +438,7 @@ static int __check_page_state_visitor(u64 addr, u64 end, u32 level, struct check_walk_data *d = arg; kvm_pte_t pte = *ptep; - if (kvm_pte_valid(pte) && !addr_is_memory(kvm_pte_to_phys(pte))) + if (kvm_pte_valid(pte) && !addr_is_allowed_memory(kvm_pte_to_phys(pte))) return -EINVAL; return d->get_page_state(pte) == d->desired ? 0 : -EPERM; -- 2.37.0.rc0.161.g10f37bed90-goog _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm