From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C428C389DF0; Wed, 13 May 2026 17:23:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778693029; cv=none; b=bSU96bTLDHWcEACBQa9/rcL2ZwvKGu7RicHGiJlClY5Nfk/rAy1EZ9cQmeaNpA0nKdzC1E+LcNjcc1w83SJyQ/RDNrnHOgt/N4ujofI55ErwXpWJjwa4skQ2jeoYbcxpVG3sP6wsKAiXFChHH9lM5zlXQI5FU6kTnACBqFYqgsM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778693029; c=relaxed/simple; bh=bVCUB+XEkZ4ZZOEMStNH8O+vVXyBxeWbiKPyxemPMoo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=dAbioTxXLbKKYt8GtcvHfwvEXnDzjfL1S6Q5c2ju3dDlSk9L9d9Et6bn3O35e6z4mmvqAMgmjxgMr/x0baVUv8v1YvcEDMlvpxjCDrvZ9tlUzQ4/lmbr0b0nRm88LDuzWboSNDh7F0cSVEbRrsmZgTkkM9CbIDN/v6LIt1SauDQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=AKKGdtbP; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="AKKGdtbP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 651B7C2BCB7; Wed, 13 May 2026 17:23:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778693028; bh=bVCUB+XEkZ4ZZOEMStNH8O+vVXyBxeWbiKPyxemPMoo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=AKKGdtbP2IKmlSlB/reSdavwF9cRGIGy/x+5lin8na7Xy3QaAhy82iwgCj4ObYrrF lPbtThIyK2Toh7Hvxenq+NZB2Kscd1J9UrtdiDL80aoOUK7+/Q5w6bD0dZAeggDk2A YMNoM57+WSWlCJxJ6RCelyJxDa3HUCY94Xh+uWxHkj1We4sK9hn0W2S6rd8Mej3/U+ /7OsGzJX9FaUyKhUyFTp1QfltlBxBmzgrDTsLnbboqLZvf8Uh7smupTvRbhCLcsktA S7ffRftzKjWsmjPwocyv6KgzFWGyo3NYlD3/8h/f8RzTiRb9mehDZF8AjBGwqPrzX1 cthG00VUIrhNA== Date: Wed, 13 May 2026 18:23:43 +0100 From: Sudeep Holla To: Sebastian Ene Cc: catalin.marinas@arm.com, maz@kernel.org, oupton@kernel.org, Sudeep Holla , will@kernel.org, joey.gouly@arm.com, korneld@google.com, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, android-kvm@google.com, mrigendra.chaubey@gmail.com, perlarsen@google.com, suzuki.poulose@arm.com, vdonnefort@google.com, yuzenghui@huawei.com Subject: Re: [PATCH v3 0/2] arm_ffa, KVM: Fix FF-A emad offset calculations Message-ID: <20260513-ludicrous-beautiful-cuttlefish-34271d@sudeepholla> References: <20260512124442.1899107-1-sebastianene@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260512124442.1899107-1-sebastianene@google.com> On Tue, May 12, 2026 at 12:44:40PM +0000, Sebastian Ene wrote: > Hi all, > > This series fixes the Endpoint Memory Access Descriptor (EMAD) offset calculations > and adds the necessary bounds checks for both the core FF-A driver and the pKVM > hypervisor. > > Prior to FF-A version 1.1, the memory region header didn't specify an explicit offset > for the EMADs, leading to the assumption that they immediately follow the header. > However, from v1.1 onwards, the specification dictates using the `ep_mem_offset` field > to determine the start of the memory access array. > > The patches in this series address this by: > 1. Updating the core `arm_ffa` firmware driver to correctly calculate the descriptor > offset using `ep_mem_offset` rather than defaulting to `sizeof(struct ffa_mem_region)`. > It also introduces bounds checking against `max_fragsize`. > 2. Enhancing the pKVM hypervisor validation logic to no longer strictly enforce that > the descriptor strictly follows the header, aligning it with the driver behavior > and the FF-A specification, while also ensuring the offset falls within the mailbox > buffer bounds. > Looks good apart from the minor nits, but how do you plan to route these changes as they are dependent for functionality but not for the build IIUC. I don't think I have any conflicting change so far, so it can go along with other pKVM changes. Let me know. > Changelog > ######### > > v2 -> this: > - Fixed typo in nvhe/ffa.c (missing sizeof) > > v1 -> v2: > - For pKVM, removed the strict placement enforcement for `ep_mem_offset` as it is not > compliant with the spec, and avoids making assumptions about the driver's memory > layout. > > Link to: > ######## > > v2: https://lore.kernel.org/all/20260430160241.1934777-1-sebastianene@google.com/ > v1: https://lore.kernel.org/all/ae9KN9nkOgDYJcGP@google.com/T/#t > > Sebastian Ene (2): > firmware: arm_ffa: Fix Endpoint Memory Access Descriptor offset > calculation > KVM: arm64: Validate the offset to the mem access descriptor > > arch/arm64/kvm/hyp/nvhe/ffa.c | 24 ++++++++++++++++++------ > drivers/firmware/arm_ffa/driver.c | 14 ++++++++++---- > include/linux/arm_ffa.h | 2 +- > 3 files changed, 29 insertions(+), 11 deletions(-) > > -- > 2.54.0.563.g4f69b47b94-goog > -- Regards, Sudeep