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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 256C9D6552C for ; Wed, 17 Dec 2025 10:14:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=/KAVFf2ooIChp5hvNI83iNG2UN3xGaSvsJVSH8BSgn4=; b=o5V3QGBldZtdZ+UA2GRj+fR53w 2tP8QzE69+MC4VcE0JjgMMmn9mmIbULbnGV4oRx7rolvTVaQ1EWajBIwDa3xYPdpCBJcrqVBHICab lRBZ4W7c8KhxPstkEnrjVd06MHJogGXUpIeC38cGHio7uKoIu3a3FbHL32lTdhqT5W+7RqBYsnl17 CegdFlNZDEbDlYfqV8i6CbnE3WcHCBlGSEwMZynPI6BzjnQ58wf7zsHxVhkNZ8O7C9jN31scfmO5L ruD6+0jXC56IvYkEUQnOnfnaPLWaOAA0Dg+7ZYam8psM8XYAs5PAGcVBujZab/ePn6d4R405ftEPD WxE/Ju2g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vVoYN-00000006YVJ-1vBF; Wed, 17 Dec 2025 10:14:43 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vVoYA-00000006YHB-2b0y for linux-arm-kernel@lists.infradead.org; Wed, 17 Dec 2025 10:14:39 +0000 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 097FD168F; Wed, 17 Dec 2025 02:14:23 -0800 (PST) Received: from e122027.arm.com (unknown [10.57.45.201]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 731543F73B; Wed, 17 Dec 2025 02:14:26 -0800 (PST) From: Steven Price To: kvm@vger.kernel.org, kvmarm@lists.linux.dev Cc: Steven Price , Catalin Marinas , Marc Zyngier , Will Deacon , James Morse , Oliver Upton , Suzuki K Poulose , Zenghui Yu , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Joey Gouly , Alexandru Elisei , Christoffer Dall , Fuad Tabba , linux-coco@lists.linux.dev, Ganapatrao Kulkarni , Gavin Shan , Shanker Donthineni , Alper Gun , "Aneesh Kumar K . V" , Emi Kisanuki , Vishal Annapurve Subject: [PATCH v12 34/46] arm64: RMI: Prevent Device mappings for Realms Date: Wed, 17 Dec 2025 10:11:11 +0000 Message-ID: <20251217101125.91098-35-steven.price@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20251217101125.91098-1-steven.price@arm.com> References: <20251217101125.91098-1-steven.price@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251217_021430_721687_AF9A21AC X-CRM114-Status: GOOD ( 11.64 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Physical device assignment is not supported by RMM v1.0, so it doesn't make much sense to allow device mappings within the realm. Prevent them when the guest is a realm. Signed-off-by: Steven Price --- Changes from v6: * Fix the check in user_mem_abort() to prevent all pages that are not guest_memfd() from being mapped into the protected half of the IPA. Changes from v5: * Also prevent accesses in user_mem_abort() --- arch/arm64/kvm/mmu.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index c30d7be27361..e71ef41fb6b1 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -1221,6 +1221,10 @@ int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa, if (is_protected_kvm_enabled()) return -EPERM; + /* We don't support mapping special pages into a Realm */ + if (kvm_is_realm(kvm)) + return -EPERM; + size += offset_in_page(guest_ipa); guest_ipa &= PAGE_MASK; @@ -1955,6 +1959,15 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, return ret; } + /* + * For now we shouldn't be hitting protected addresses because they are + * handled in private_memslot_fault(). In the future this check may be + * relaxed to support e.g. protected devices. + */ + if (vcpu_is_rec(vcpu) && + kvm_gpa_from_fault(kvm, fault_ipa) == fault_ipa) + return -EINVAL; + if (nested) adjust_nested_fault_perms(nested, &prot, &writable); -- 2.43.0