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 60A12108E1DA for ; Thu, 19 Mar 2026 10:27:48 +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:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=foaoda/fy8EAWFYlFaBL37MQIpGUcNcrbVYNPPRRRDQ=; b=bgedfHcDajj+Oc+Q08E84wFfTV CuxF1MM4vPgwydsl9CXVHwBNlE4q91sy2H7/FDORuFHfgFhAJQDzEFZanKwjwj/EGjWs2tHRgGESJ XuVCk/jjabjNRZdD/i8XII7nvq98XpqYXdenaKsof9Suvu20MUTV9kVm79IJ0yNM5GNRUxkJZaTFq r1Lme1IwigvaQlmL6psmDjKtUPZwKH2t0AV+tuKFcfsB0R/FQVGOq50GPi3zqIPkRVlg/hNCFN8wY vYe/gZqXejV7WaCePYqP8h8uNkCEL6GKlA1WbdIsUbCge/V1QXUPMYbxlLO3BfaLFnpzxtO9CXIlB G5UEYX/w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1w3AbP-0000000APgJ-1VK4; Thu, 19 Mar 2026 10:27:43 +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 1w3AbN-0000000APfz-1ltP for linux-arm-kernel@lists.infradead.org; Thu, 19 Mar 2026 10:27:42 +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 79DA21A25; Thu, 19 Mar 2026 03:27:34 -0700 (PDT) Received: from e124191.cambridge.arm.com (e124191.cambridge.arm.com [10.1.197.45]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 46C7D3F7BD; Thu, 19 Mar 2026 03:27:37 -0700 (PDT) Date: Thu, 19 Mar 2026 10:27:34 +0000 From: Joey Gouly To: Steven Price Cc: kvm@vger.kernel.org, kvmarm@lists.linux.dev, 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, 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: Re: [PATCH v13 37/48] arm64: RMI: Prevent Device mappings for Realms Message-ID: <20260319102734.GC3942350@e124191.cambridge.arm.com> References: <20260318155413.793430-1-steven.price@arm.com> <20260318155413.793430-38-steven.price@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260318155413.793430-38-steven.price@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260319_032741_522891_17B39A2F X-CRM114-Status: GOOD ( 21.68 ) 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 On Wed, Mar 18, 2026 at 03:54:01PM +0000, Steven Price wrote: > Physical device assignment is not supported by RMM v1.0, so it But we're targetting 2.0 now! I guess just change it to something about device support being a later feature. Thanks, Joey > 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 ad1300f366df..7d7caab8f573 100644 > --- a/arch/arm64/kvm/mmu.c > +++ b/arch/arm64/kvm/mmu.c > @@ -1222,6 +1222,10 @@ 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; > > @@ -1965,6 +1969,15 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, > return 1; > } > > + /* > + * 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 > >