From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id DAD383D75A4; Fri, 20 Mar 2026 16:45:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774025114; cv=none; b=SVeQSmwBZ/x27iYVZiNjN8sBHZvVg/VioCHLYRnhJCHMzWcr25PU1H6hC+fMf9f4H+xeZSV5kK5s7iP8BMMvtoMLZ4gxVBiT8Ko9CbXvLCfsOSSlGMOzr9J8wxLpVFPXytGDLuXv6lJJOwoq1IuIwcawnXec8uSnYU5GtjxuAnM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774025114; c=relaxed/simple; bh=yurgVKs3bGZmMYJDWdi483cyucCah3RKVTMIIzx+Q/A=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=c19/ImgTikq4JZxerXwaUAkENryFm9GGK0eXB3I3AjafzXXF3LEiWcsPRe70YmHneW4GqBDXXwBZNtbNV8/x3DAf/Z/9Q6Sd4sK1mB8GYk4rL/UOx99MKCofrBQ9572FCaP4nj8AwJboHxB7HrMfpYIwhjvSohFLfxAUgpOxL0Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com 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 501C71682; Fri, 20 Mar 2026 09:45:06 -0700 (PDT) Received: from [10.1.29.20] (unknown [10.1.29.20]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0D5063F7BD; Fri, 20 Mar 2026 09:45:07 -0700 (PDT) Message-ID: Date: Fri, 20 Mar 2026 16:45:07 +0000 Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v13 37/48] arm64: RMI: Prevent Device mappings for Realms To: Wei-Lin Chang , kvm@vger.kernel.org, kvmarm@lists.linux.dev Cc: 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 References: <20260318155413.793430-1-steven.price@arm.com> <20260318155413.793430-38-steven.price@arm.com> From: Steven Price Content-Language: en-GB In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 19/03/2026 18:46, Wei-Lin Chang wrote: > 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 >> 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 > > Hi, > > What is private_memslot_fault()? I don't see it anywhere in the series & > upstream. Oh dear, that comment is out of date ;) It's now become gmem_abort()... >> + * relaxed to support e.g. protected devices. >> + */ >> + if (vcpu_is_rec(vcpu) && >> + kvm_gpa_from_fault(kvm, fault_ipa) == fault_ipa) >> + return -EINVAL; >> + > > Additionally, there is a hunk almost identical to this one here in added > in patch 27. Which is what this chunk says. It appears I screwed up a rebase at some point! This whole patch can really be dropped and the kvm_phys_addr_ioremap() change moved into another patch. Thanks, Steve > Thanks, > Wei-Lin Chang > >> if (nested) >> adjust_nested_fault_perms(nested, &prot, &writable); >> >> -- >> 2.43.0 >>