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 81DD526A0A7; Mon, 13 Apr 2026 15:25:36 +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=1776093936; cv=none; b=Kiiq/TZU0r88s4pleYRRnRkeXatRIasnmDkGgW2E+qIJPqvC/GMwx6JTBv8Xu992rJVrob7q4CWANDNqhgxZoKZ6+EqBAdz70iIIQVk/Qheh+IUCiieu+TFhBHC9ICpSSKmVkO1GtzHu+nJ1dS9BeNdljdmD0dlybxmMp1oHq5I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776093936; c=relaxed/simple; bh=cU9lrhEmZpvQLEgoKVEj0GRhcNMapbzoQ668g/ZSdDU=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=BeHT/+p8KW6wSFf6c1iyu8rnRgNQ/0P6JUwqRNNlIveEkaf+i2jSyDe/ACkzOLnFAMhnhsLA2Kb9nolztL8FFDa0DKkv65IspBoCNUNgrLQ0ZzArWqxEidkEeQJ3OEy0sDuAGBu+WoDJnOjd0+iZ5T9PzFx04ocg2fZhW/6iA+o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=gUm7qJ9y; 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="gUm7qJ9y" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3DEDCC2BCB4; Mon, 13 Apr 2026 15:25:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776093936; bh=cU9lrhEmZpvQLEgoKVEj0GRhcNMapbzoQ668g/ZSdDU=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=gUm7qJ9yF0OgIhNg+F92vYs9RmpAI3ImKBtfqic40EOJqj5yt5jRmNv0ejprfID+l jjcCEfOW0mEasF+VZaIH3vFWd1t8L7rh8rfeVQhc2eL3dsVoKzDli1lgTAxjwr2oSe cDd10Fmf12aUEONAemC706ufTDWNpfuVc3wTVoPWP4CNdurUENl1m7LZgA30Bvl8fM wZe54h9dWcTlWGA69fLQafkLljy1VUZ+m3syyOh+wFFo50Ll6GYiwwEq0KSn5D8lz7 +0DO+pKdYnxTfw0fHZq2xZUH9trnNqvchCtOzKln4PGK3D/+2sFoF3bFtC4SjC/bpO FR/QCkqKIycFg== X-Mailer: emacs 30.2 (via feedmail 11-beta-1 I) From: Aneesh Kumar K.V To: Jason Gunthorpe Cc: Mostafa Saleh , iommu@lists.linux.dev, linux-kernel@vger.kernel.org, robin.murphy@arm.com, m.szyprowski@samsung.com, will@kernel.org, maz@kernel.org, suzuki.poulose@arm.com, catalin.marinas@arm.com, jiri@resnulli.us Subject: Re: [RFC PATCH v2 1/5] dma-mapping: Avoid double decrypting with DMA_RESTRICTED_POOL In-Reply-To: <20260413123559.GI3694781@ziepe.ca> References: <20260330145043.1586623-1-smostafa@google.com> <20260330145043.1586623-2-smostafa@google.com> <20260330150654.GA809900@ziepe.ca> <20260413123559.GI3694781@ziepe.ca> Date: Mon, 13 Apr 2026 20:55:28 +0530 Message-ID: Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Jason Gunthorpe writes: > On Mon, Apr 13, 2026 at 11:30:38AM +0530, Aneesh Kumar K.V wrote: > >> I know there is a v3, but I=E2=80=99m commenting here to check whether w= e really >> need to do this now. In my opinion, we can keep this much simpler by >> treating all swiotlb allocations as decrypted allocations.=20 > > That's not going to work when we get to supporting T=3D1 devices that > may still want SWIOTLB for encrypted memory. > Earlier discussions indicated that a T=3D1 device would not require a bounce buffer. On ARM, we require such devices to support 64-bit DMA so they can operate with an unprotected IPA. -aneesh