From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1305CC4332F for ; Wed, 23 Nov 2022 11:26:10 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oxns3-0005Sa-FT; Wed, 23 Nov 2022 06:24:51 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oxnrY-00057A-Iz for qemu-devel@nongnu.org; Wed, 23 Nov 2022 06:24:25 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oxnrV-0007QL-MG for qemu-devel@nongnu.org; Wed, 23 Nov 2022 06:24:20 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1669202655; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=sA6kQa63kT5DBa73irm8C3MNfC5MWe86Uv1W5TsLgEg=; b=e9jhPpzHPDozCz3gzWJqvkE+te0ORk/7vlao7lxeimD4esUg925g94JEV2oYQ7CnvgTqJ4 ljhxv897TcG+iJUjbvp2BVKqUHXIR9gsyI7U2Guy4kDG66ps/BL0q1WkUfyytlR48wZhpe n80dCsU3T37PHh2oqSkNLtFklXVbuTw= Received: from mail-wr1-f70.google.com (mail-wr1-f70.google.com [209.85.221.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-265-M1rnpBQOO8a1_9aDfB4lcg-1; Wed, 23 Nov 2022 06:24:14 -0500 X-MC-Unique: M1rnpBQOO8a1_9aDfB4lcg-1 Received: by mail-wr1-f70.google.com with SMTP id j30-20020adfa55e000000b00241b49be1a3so4867685wrb.4 for ; Wed, 23 Nov 2022 03:24:14 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=sA6kQa63kT5DBa73irm8C3MNfC5MWe86Uv1W5TsLgEg=; b=j0Z4rfnMdvIpdZjG8k6I0sfXL6ERazT/pbSOxhHgjyBUtrxSHMNvaejqG/sNbdM5M6 zhI8WFCiFRZstGvDbWgt1kaFm7uhxRs9ccu9vrQaL1ni3jMlOk8Jk+ttjkjXXKJvi5z8 Ig+5uXvjbwZaUbWCuH7fyZ5fk9orve7bBqIJXIoQwY5nXVNh7oph/Zdf6bw1ODXiLLbX umfWuWUYMcLHLt6njw3p7NBV1+7TCxgSZhOGvIQnM344/AsfQW1tAdEMBFmmX1r3jh4H WBPf2AmwAFyoImlVwONbhLclGiUbDl5Q1fuEBewafkw2l3QXwlpwsgKYp3OTuSINib5O fYHQ== X-Gm-Message-State: ANoB5plwLi1Y0uyb3SqAIK9mhAql0ofyC5AHLQcSnrTKACrFd/r9Q5ue 2pZ9S7Q/9bVzNpr7oAwDAV+FtANggbL0ZJhp8IRtrSN9Rm+QYfmcaMLnDDggFKR2jFmPMqwE+a+ 1jK6bV/0dhsQbvsI= X-Received: by 2002:adf:a158:0:b0:241:b98f:fa22 with SMTP id r24-20020adfa158000000b00241b98ffa22mr11073269wrr.648.1669202653203; Wed, 23 Nov 2022 03:24:13 -0800 (PST) X-Google-Smtp-Source: AA0mqf4j2biAr5LPDpMbdNgil+8+C9dYx3/hfihHXBSHFq9IW8jkCOLwXLjTxyWmNV2NGkAp8zEV8Q== X-Received: by 2002:adf:a158:0:b0:241:b98f:fa22 with SMTP id r24-20020adfa158000000b00241b98ffa22mr11073256wrr.648.1669202652948; Wed, 23 Nov 2022 03:24:12 -0800 (PST) Received: from redhat.com ([2.52.16.74]) by smtp.gmail.com with ESMTPSA id r13-20020a056000014d00b0024165454262sm16315408wrx.11.2022.11.23.03.24.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 23 Nov 2022 03:24:12 -0800 (PST) Date: Wed, 23 Nov 2022 06:24:09 -0500 From: "Michael S. Tsirkin" To: Eric Auger Cc: Stefan Berger , eric.auger.pro@gmail.com, qemu-devel@nongnu.org, alex.williamson@redhat.com, stefanb@linux.vnet.ibm.com, cohuck@redhat.com, f4bug@amsat.org Subject: Re: [PATCH v5 1/2] sysemu: tpm: Add a stub function for TPM_IS_CRB Message-ID: <20221123062202-mutt-send-email-mst@kernel.org> References: <20220506132510.1847942-1-eric.auger@redhat.com> <20220506132510.1847942-2-eric.auger@redhat.com> <96940f79-a6e0-d14f-5d74-abe280846f26@linux.ibm.com> <20221123013441-mutt-send-email-mst@kernel.org> <45e916e5-9297-a8e4-c539-123e0ee6347c@redhat.com> <20221123043005-mutt-send-email-mst@kernel.org> <9ffcc26f-e3b2-77f1-5929-6c6caf1ea64d@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <9ffcc26f-e3b2-77f1-5929-6c6caf1ea64d@redhat.com> Received-SPF: pass client-ip=170.10.129.124; envelope-from=mst@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Wed, Nov 23, 2022 at 12:10:09PM +0100, Eric Auger wrote: > > > On 11/23/22 10:30, Michael S. Tsirkin wrote: > > On Wed, Nov 23, 2022 at 09:18:39AM +0100, Eric Auger wrote: > >> Hi, > >> > >> On 11/23/22 07:36, Michael S. Tsirkin wrote: > >>> On Fri, May 06, 2022 at 09:47:52AM -0400, Stefan Berger wrote: > >>>> On 5/6/22 09:25, Eric Auger wrote: > >>>>> In a subsequent patch, VFIO will need to recognize if > >>>>> a memory region owner is a TPM CRB device. Hence VFIO > >>>>> needs to use TPM_IS_CRB() even if CONFIG_TPM is unset. So > >>>>> let's add a stub function. > >>>>> > >>>>> Signed-off-by: Eric Auger > >>>>> Suggested-by: Cornelia Huck > >>>> Reviewed-by: Stefan Berger > >>> ... and now in 7.2 vdpa needs a dependency on tpm too, what a hack :( > >>> And what exactly is it about TPM CRB that everyone needs to > >>> know about it and skip it? The API does not tell ... > >> An excerpt of one reply I made at that time: > >> > >> The spec (CG PC Client Platform TPM Profile (PTP) > >>     Specification Family “2.0” Level 00 Revision 01.03 v22, page 100)  > >> says that the command/response data "may be defined as large as 3968", > >> which is (0x1000 - 0x80), 0x80 being the size of the control struct. > >> so the size of the region logically is less than a 4kB page, hence our > >> trouble. > >> > >> We learnt in the past Windows driver has some stronger expectation wrt > >> memory mapping. I don't know if those latter would work if we were to > >> enlarge the window by some tricks. > >> > >> https://trustedcomputinggroup.org/wp-content/uploads/Mobile-Command-Response-Buffer-Interface-v2-r12-Specification_FINAL2.pdf > >> says > >> > >> " > >> Including the control structure, the three memory areas comprise the > >> entirety of the CRB. There are no constraints on how those three memory > >> areas are provided. They can all be in system RAM, or all be in device > >> memory, or any combination. > >> > >> Thanks > >> > >> Eric > > So we put it in system RAM then? But why isn't DMA there allowed? > > I don't think there is any need and since it violates the alignment > check in VFIO we discard the region from DMA mapped ones. > > Thanks > > Eric If that's all then we could just check alignment - why are we bothering with a tpm specific hack? > > > >>>>> --- > >>>>> include/sysemu/tpm.h | 6 ++++++ > >>>>> 1 file changed, 6 insertions(+) > >>>>> > >>>>> diff --git a/include/sysemu/tpm.h b/include/sysemu/tpm.h > >>>>> index 68b2206463c..fb40e30ff60 100644 > >>>>> --- a/include/sysemu/tpm.h > >>>>> +++ b/include/sysemu/tpm.h > >>>>> @@ -80,6 +80,12 @@ static inline TPMVersion tpm_get_version(TPMIf *ti) > >>>>> #define tpm_init() (0) > >>>>> #define tpm_cleanup() > >>>>> > >>>>> +/* needed for an alignment check in non-tpm code */ > >>>>> +static inline Object *TPM_IS_CRB(Object *obj) > >>>>> +{ > >>>>> + return NULL; > >>>>> +} > >>>>> + > >>>>> #endif /* CONFIG_TPM */ > >>>>> > >>>>> #endif /* QEMU_TPM_H */