From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792698012; b=MZDZUJpiOwyxnYneP3wZyYNP/2dxwFYawflClkVof4hQsOsp8X5LyHiTkmDxRDSlNbWY MzxwHyJ9GVOdJ4kwLsVumbTouop1FUvRzYOsSJM5bLVhriqTrpD19xF4Q/JU9Q5IF2nMm F08MAQN5WtpDJk2BLI4MV9g/ve1GVR33nAbsi36lUbI9jQsPbBIP2wPrGTA0UaoyijN3k X8rDTzgMPS+4w7sgWXEsCOJS7KaP6t4tcMgEiXsln73xALYqbbdyYavSGernOHkxNC7MF mBYaZImAzckFz2kP+k6FYTp5PJawF8oxpvPUMbstH4SrlFNPaqru4DNBUM+k7c4eUjg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792698012; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: References:MIME-Version:Content-Type:Content-Disposition: Content-Transfer-Encoding:In-Reply-To; bh=q5JTgohXUR8Op6NlSpjnxP0zgVyww3zZN/iYh+n3im0=; b=2lHL6VzxLe4IqeNkn0Nr0K8v0+0scoz2mgKNzDlhNmIornsx7Pf1uZ7hvwf7AL5QlAo5 DAEBnr9hH/AKXREX5jo7/ldCgSBhMY2cxx2KJjaLgLqftrQhdvOAhXEHlyfg5uU5X0S2T kdXlHu/eE8H3dx6dHzUlKJ3tIOqI9wfCR+rfrRgATjBuP06ZzAY9D1cAu+pFWhuYGo1Mp A6TNHY4TpevuTEN3dkxs9KaqEF+Cv/xDhAjevX6LH6xKM1acyhC/ktWeHbidc4CccpBCC Dwk45ACmCW1RTKnYAUOeY6sEBZ+4aZ53/wfJ7F50b8/nFJs6/pYhr/v2mA2GWP7HTcg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=HfnsLZh2; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with UTF8SMTPS id 9FAEB606A31B; Thu, 22 Oct 2026 19:40:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=HfnsLZh2 Received: by smtp.kernel.org (Postfix) with UTF8SMTPSA id E04F11F01828; Thu, 22 Oct 2026 19:40:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792698012; bh=q5JTgohXUR8Op6NlSpjnxP0zgVyww3zZN/iYh+n3im0=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=HfnsLZh2mR0+/B55NAr+FDqKkXP3gp8VdcfFaDuzdDFhGd8HslFepY4FSDOsg5TC8 9TGoS10sS4qDN+u+S/yBZkD5toajxWzyof1x0YkJrraLJAU+0im1NSsgvIYJnO2E+Z sMEK6bo4G1yrEyVCLvyGS9miMNKhqjILvQ7ireFl/idxEl1/IR2UvadcGz2QO+jkFi lvMDcdI9iQdWnq6DhrFuw2sZ5mFtoa+4uNOko8j1DJvWEVs1++UeNSPwDqgh0l8ee5 hjOS0mztl6thTUKCfs/mG5f+JVhBkRDcY1YFpq4QBUBfF6mXTv/tiCDiTb5QJQ+6ni JpyUKDRu0j7pA== Date: Thu, 22 Oct 2026 22:40:08 +0300 From: Jarkko Sakkinen To: Jason Gunthorpe Cc: Mimi Zohar , Jiri Pirko , Dionna Glaze , linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org, linux-doc@vger.kernel.org, david.quigley@intel.com, lukas@wunner.de, ksinyuk@kernel.org, rodrigo.vivi@intel.com, cedric.xing@intel.com, sameo@meta.com, James.Bottomley@hansenpartnership.com, aik@amd.com, jpiotrowski@nvidia.com, qinkun@google.com, pgonda@google.com, jic23@kernel.org, alistair.francis@wdc.com, ankita@nvidia.com, suzuki.poulose@arm.com, kas@kernel.org, rick.p.edgecombe@intel.com, elena.reshetova@intel.com, dave.hansen@linux.intel.com, sathyanarayanan.kuppuswamy@linux.intel.com, peter.fang@intel.com, roberto.sassu@huawei.com Subject: Re: [PATCH RFC 00/20] attestation: Add a common subsystem and TDX support Message-ID: References: <20261019225658.GS13920@nvidia.com> <103486a4a29ecc7b72940dd051c00ae59266bd05.camel@linux.ibm.com> <20261021143529.GP3008132@nvidia.com> <8d8833fac61558a94af415143530884349584a2f.camel@linux.ibm.com> <2342b42699292d4e5fc85e5dd4d351a3f29ae336.camel@linux.ibm.com> <20261022185133.GA3746973@nvidia.com> <20261022192322.GD3746973@nvidia.com> X-Mailing-List: linux-api@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20261022192322.GD3746973@nvidia.com> On Thu, Oct 22, 2026 at 04:23:22PM -0300, Jason Gunthorpe wrote: > On Thu, Oct 22, 2026 at 10:19:41PM +0300, Jarkko Sakkinen wrote: > > On Thu, Oct 22, 2026 at 03:51:33PM -0300, Jason Gunthorpe wrote: > > > On Thu, Oct 22, 2026 at 07:24:57AM -0400, Mimi Zohar wrote: > > > > > Isn't the hypervisor what we are doing now? I mean multiple extension > > > > > originators share the same register and eventually the same log. Or do > > > > > you suggest to go even further having a "generic_registerX" exposed for > > > > > every hw implementation allowing the user to have full abstraction? > > > > > The "generic_registerX" would be always alias to something hw specific, > > > > > like RTMR2 for example of TDX. > > > > > > > > I definitely prefer the latter, as everything continues to work as is with > > > > minimal, if any, change. > > > > > > > > AI's wording: > > > > • The Virtual Mapping: The [attestation] subsystem exposes "Virtual RTMRs" > > > > (vRTMRs) internally to the kernel. > > > > > > > > • IMA's Dedicated Lane: The kernel config routes IMA to vRTMR_IMA. > > > > > > I was thinking something similar too > > > > > > I called this "PCR policy" in my previous posting, but in-kernel I > > > would expect something like IMA to request the "IMA PCR" from the > > > current attestation policy. > > > > > > This could be a locality 0 TPM PCR, a locality 2 PCR for a DRTM > > > launch, a TDX RTMR, etc. It keeps the layout in one place, and lets > > > the multiplexor steer it to different hardware. > > > > 5 Authenticated hibernate [1] > > > > This is on the table at least. > > Yeah, any in-kernel use of PCRs has to fit into the overall system > policy. Like maybe you don't want to use PCR 5 if you have DRTM, or > you want to do hibernation using an alternative ROT from TPM.. Just mentioning it for completeness but it is, of course, not a committed reservation as the patch set is still only an RFC. I'm looking forward to test the feature as soon as I have the bandwidth to setup a proper environment for it. > > Jason Br, Jarkko