From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) (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 8087934B69C for ; Thu, 13 Nov 2025 12:04:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.176.79.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763035461; cv=none; b=HuOivgsgcg5Q09PkIXJ0fxnFGdYzMASyivxv7rugz7x+28EIuzB75RJ6Z3IYsiqYaLnRSDzo4Dcs7f5m+fIQ9H6iWStcPkJESEvHepn10hCWa2WaK/Uf9rXlKlQJhjE1tpemDaW2Uq80YLpILXyl+wFctPjG49K91u8DXhS9N+I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763035461; c=relaxed/simple; bh=hozLaqRPP4hliFEC+8gb8RgILiPWL6kBTjMJS2Tagho=; h=Date:From:To:CC:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=iL8WRueb/QgbBvlFpcs4FJ0N4nXsJcPLONj6yLhBztWsDw8qVuG8ECsUGEnPlLnz3ZhoJwbS6qduOmzEQyweCwZQtPp3qY+BqyqOf31qi299cnvwu2xIQgUN29lfAhjOmMP4UmVRe6+J4i/msMGcKoIm6bVmOIAL38t4+MNRHao= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=185.176.79.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.18.186.31]) by frasgout.his.huawei.com (SkyGuard) with ESMTPS id 4d6f7M2r27zJ468k; Thu, 13 Nov 2025 20:03:43 +0800 (CST) Received: from dubpeml100005.china.huawei.com (unknown [7.214.146.113]) by mail.maildlp.com (Postfix) with ESMTPS id 7514C140277; Thu, 13 Nov 2025 20:04:17 +0800 (CST) Received: from localhost (10.203.177.15) by dubpeml100005.china.huawei.com (7.214.146.113) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.36; Thu, 13 Nov 2025 12:04:16 +0000 Date: Thu, 13 Nov 2025 12:04:15 +0000 From: Jonathan Cameron To: Dan Williams CC: , , Xu Yilun Subject: Re: [PATCH v2 7/8] PCI/TSM: Add pci_tsm_guest_req() for managing TDIs Message-ID: <20251113120415.000026cf@huawei.com> In-Reply-To: <20251113021446.436830-8-dan.j.williams@intel.com> References: <20251113021446.436830-1-dan.j.williams@intel.com> <20251113021446.436830-8-dan.j.williams@intel.com> X-Mailer: Claws Mail 4.3.0 (GTK 3.24.42; x86_64-w64-mingw32) Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: lhrpeml500012.china.huawei.com (7.191.174.4) To dubpeml100005.china.huawei.com (7.214.146.113) On Wed, 12 Nov 2025 18:14:45 -0800 Dan Williams wrote: > A PCIe device function interface assigned to a TVM is a TEE Device > Interface (TDI). A TDI instantiated by pci_tsm_bind() needs additional > steps taken by the TVM to be accepted into the TVM's Trusted Compute > Boundary (TCB) and transitioned to the RUN state. > > pci_tsm_guest_req() is a channel for the guest to request TDISP collateral, > like Device Interface Reports, and effect TDISP state changes, like > LOCKED->RUN transititions. Similar to IDE establishment and pci_tsm_bind(), > these are long running operations involving SPDM message passing via the > DOE mailbox. > > The path for a TVM to invoke pci_tsm_guest_req() is: > * TSM triggers exit via guest-to-host-interface ABI (implementation specific) > * VMM invokes handler (KVM handle_exit() -> userspace io) > * handler issues request (userspace io handler -> ioctl() -> > pci_tsm_guest_req()) > * handler supplies response > * VMM posts response, notifies/re-enters TVM > > This path is purely a transport for messages from TVM to platform TSM. By > design the host kernel does not and must not care about the content of > these messages. I.e. the host kernel is not in the TCB of the TVM. > > As this is an opaque passthrough interface, similar to fwctl, the kernel > requires that implementations stay within the bounds defined by 'enum > pci_tsm_req_scope'. Violation of those expectations likely has market and > regulatory consequences. Out of scope requests are blocked by default. > > Co-developed-by: Xu Yilun > Signed-off-by: Xu Yilun > Signed-off-by: Dan Williams Reviewed-by: Jonathan Cameron