From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qk1-f178.google.com (mail-qk1-f178.google.com [209.85.222.178]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7CC82C2EA for ; Thu, 12 Mar 2026 12:06:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.222.178 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773317170; cv=none; b=lNaO6PEkjkC4Vmly19oVtZZHO/IHvW/GKlUFjPW0UisEkXUIOJ0F9QvmaU7aJ/QbAtoWa4dqzjyIrj98NBoG48oPpZ1R4k8yHoulAkIh3duEKzXQINdGMvf3qS+coImJRHP+sCazhEzulToXABBrt3+E4QMR+zJrCKrWbLybrvs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773317170; c=relaxed/simple; bh=pLE9KQjABbXYq0V8sOoF2HYf/JGl7DSdVHj+w9thxVk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=THBb+EM2jyhquG4CTks7/21F/5vxOvDG7yqLkZ40ktZzRLv4YE700/f/MuaIdX3MOY02e4B63tBb81aEg7RzDUG6NbYssAT7NaY1gG3I/kUupX/3ifaqIpU9aMzRZYotGO2/5DyhwieHb5hJxBE/aeLhKN6LNiu2xA/AtuN4OzY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ziepe.ca; spf=pass smtp.mailfrom=ziepe.ca; dkim=pass (2048-bit key) header.d=ziepe.ca header.i=@ziepe.ca header.b=gAoZ5GMa; arc=none smtp.client-ip=209.85.222.178 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ziepe.ca Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ziepe.ca Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ziepe.ca header.i=@ziepe.ca header.b="gAoZ5GMa" Received: by mail-qk1-f178.google.com with SMTP id af79cd13be357-8cd785a8783so100192385a.0 for ; Thu, 12 Mar 2026 05:06:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ziepe.ca; s=google; t=1773317168; x=1773921968; darn=lists.linux.dev; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=Pw97G/mFXVE/FuLAkp3lotBvQF2JekIeUS8x5bLQ+LE=; b=gAoZ5GMaTcXUILNehPSyuuy72dfA3pAyr+CAIdKvBcxl/MuwhT0xjOqM2P1OVsarFr OkmTa5Ig+3JMp4hdBJ7pfSv6jaTP9lRczRCd/CCvxSP+DnPXzclvqemm7g9gPOKbJg0f NjJn7J6VTbtHcelxAll/2t1cHACLKrqn3ansMqlrMnlwnHUWxwK4ZohBjS3w7xU2q0V5 ZskDA5y88DxDO+2O1CihRC06l3LHZnlygrG6rhjrwkkJRQdnvVs5eJlm1Db/jeEyzEr7 bEdcEAFcJFuBe4maZdds7lH3uXoDiQMTlgF0dIaCKXAJNTuP3KtnOHREzjaInqqpjHoF TEJA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1773317168; x=1773921968; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Pw97G/mFXVE/FuLAkp3lotBvQF2JekIeUS8x5bLQ+LE=; b=ZmVY5mpAEMQ72VSiBigjrJvrjrcqypfGWNqPNjZTpj3SHyObqxO61MhxaZkwj18ZXO 9jG4JBUMLTCH7u0YH/JHkRqvUuWdnxIRmRAp2CQJi8Igsts5KTm+yjX792ZtvrOelcgi KHf0HAqi54xsj4Q8mpCcszVc7JnNPHqOjGBJKHomUUbkzySlpwh9wT6ME3BatpjmpBTE JW+csg8MUPb7bX6jNl4dKF5d7bvLCuyi5wAZg2EbXEfRUFzgEu2T8aheSUdjoqW8suWt AbSPS6DFr29yVK/J+fzUmM774zil8eIVcEyNxbydYFAMgBblms5jc7kw2oPN6dK0Us/D zsug== X-Forwarded-Encrypted: i=1; AJvYcCUp2V7aWhgUfa1MBnm6tL5GXlyWvC0XZDo1tVza9ipDqSrJYxTR2jiZfh9dbXLTFa+h1jZ70A==@lists.linux.dev X-Gm-Message-State: AOJu0YwVymg1ar9NkcMVVc2QS8Mt1oD/X3Y8WfReSmZq1irzZx80O/Uo HjxLL0/lh5bcRn6Q30V19mbY88FdzBN2sO75buN+t9PUrPM05tM4EXw9dv9hTAicDtM= X-Gm-Gg: ATEYQzwdnGfhI6idrpiALUGRgOZhNy6LoBO7OIV6lpP4xqfVrRqlt7ImtszZn00PJ11 UyaUmlrdiVe+r+yV/ZR5b8HOmEnTooAQiHXoOvvWWPh0ed7ZvnV+l/2es2dPYU5ERCrE6u9897N hHWgv7b7vK9qwiDNQwQWbB76qa7HceEkbiKbhU7hLaR5gvm9OnyqzZNBpn/IZ/5el1ZgSGWU3xI u1XB/mEVsATw6ah60JQUIC0/82xAZivf5J1MkqaNyLuGPGkrBi4DGaaUFvMqRs/vvTubOwYsW71 MZwVeHlThJ9ocDXhbi6ldJpuKh3Wo5mIgUCGmR6qHp7VAo+pljzSHwpChyI8vEEbFGoU1Aw7JFY WiQjNJCz/yzEDNOOZnhGSk/CzEg6k1uGfCWl834tztxK7xSkGnZOINF0PB7L7hYUOeIP7z0LmNq cLsTV+aDvvpmgm8jLs5AVjTU/m15F7oiTLFPAD2rUAweC4S0FpXK9jfcRzOmEW/Fcgv7HUFZlCv uCjE5NH X-Received: by 2002:a05:620a:4e93:b0:8cd:a4d8:cd8d with SMTP id af79cd13be357-8cda4d8d254mr527718485a.14.1773317168272; Thu, 12 Mar 2026 05:06:08 -0700 (PDT) Received: from ziepe.ca (hlfxns017vw-142-162-112-119.dhcp-dynamic.fibreop.ns.bellaliant.net. [142.162.112.119]) by smtp.gmail.com with ESMTPSA id af79cd13be357-8cda1fbcd23sm361027485a.1.2026.03.12.05.06.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 12 Mar 2026 05:06:07 -0700 (PDT) Received: from jgg by wakko with local (Exim 4.97) (envelope-from ) id 1w0enm-00000006ejP-0ZCe; Thu, 12 Mar 2026 09:06:06 -0300 Date: Thu, 12 Mar 2026 09:06:06 -0300 From: Jason Gunthorpe To: Jiri Pirko Cc: Leon Romanovsky , dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, iommu@lists.linux.dev, linux-media@vger.kernel.org, sumit.semwal@linaro.org, benjamin.gaignard@collabora.com, Brian.Starkey@arm.com, jstultz@google.com, tjmercier@google.com, christian.koenig@amd.com, m.szyprowski@samsung.com, robin.murphy@arm.com, sean.anderson@linux.dev, ptesarik@suse.com, catalin.marinas@arm.com, aneesh.kumar@kernel.org, suzuki.poulose@arm.com, steven.price@arm.com, thomas.lendacky@amd.com, john.allen@amd.com, ashish.kalra@amd.com, suravee.suthikulpanit@amd.com, linux-coco@lists.linux.dev Subject: Re: [PATCH net-next v3 1/2] dma-mapping: introduce DMA_ATTR_CC_DECRYPTED for pre-decrypted memory Message-ID: <20260312120606.GC1469476@ziepe.ca> References: <20260305123641.164164-1-jiri@resnulli.us> <20260305123641.164164-2-jiri@resnulli.us> <20260308101948.GO12611@unreal> <20260309131530.GJ1687929@ziepe.ca> <20260309140233.GW12611@unreal> <20260309151857.GO1687929@ziepe.ca> <20260312003408.GA1469476@ziepe.ca> Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Thu, Mar 12, 2026 at 10:03:37AM +0100, Jiri Pirko wrote: > >Alot of device MMIO is decrypted by nature and can't be encrypted, so > >you'd have to use both flags. eg in VFIO we'd want to do this. > > Why both flags? Why MMIO flag is not enough? You still want to hit > "if (attrs & DMA_ATTR_MMIO) {" path, don't you? Because we will eventually have both decrypted and encrypted MMIO. > I mean, CC_DECRYPTED says the memory to be mapped was explicitly > decrypted before the call. MMIO was not explicitly decrypted, it is > decrypted by definition. For me that does not fit the CC_DECRYPTED > semantics. I would say CC_DECRYPTED means that pgprot_decrypted must be used to form a PTE, and !CC_DECRYPTED means that pgprot_encrypted() was used This flag should someday flow down into the vIOMMU driver and set the corresponding C bit the IOPTE (for AMD) exactly as the pgprot does. Less about set_memory_encrypted as that is only for DRAM. Jason