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 ws5-mx01.kavi.com (ws5-mx01.kavi.com [34.193.7.191]) (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 A7ECDC77B61 for ; Mon, 10 Apr 2023 10:06:57 +0000 (UTC) Received: from lists.oasis-open.org (oasis.ws5.connectedcommunity.org [10.110.1.242]) by ws5-mx01.kavi.com (Postfix) with ESMTP id E41EC2B01A for ; Mon, 10 Apr 2023 10:06:56 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id DA52698638E for ; Mon, 10 Apr 2023 10:06:56 +0000 (UTC) Received: from host09.ws5.connectedcommunity.org (host09.ws5.connectedcommunity.org [10.110.1.97]) by lists.oasis-open.org (Postfix) with QMQP id CF1D79862A5; Mon, 10 Apr 2023 10:06:56 +0000 (UTC) Mailing-List: contact virtio-dev-help@lists.oasis-open.org; run by ezmlm List-ID: Sender: Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id BFE1D98631E for ; Mon, 10 Apr 2023 10:06:56 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-MC-Unique: _2-E7JnaP7Sn2fTlUP5jlg-1 X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1681121213; 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=SIuPh0Q7aaEGGPtMDp8rtCrHeHZutODr6kSvT7g9XWY=; b=fwTQw5PanLkL5Kw3dlIU/yVzBIRTqe0ys8jPY8oALrf0pzlQru9QKl423lRM7aR/kZ YheEFn+u5K/sDES8RwYKB6QLAorl23SGZJXXiarrCjTpCJFbdCnmg+GVzcCEDs+maJW4 t2rMZIOWJuGqI/l1B3bzs9VThaITzuW2oQfhFGvnS4D32wbdcsuBEp5if6p7qBGiZNrn z60/QQHRxbjq1WacrXODm31Zg0iyVjKwieAFyzjmuVaTh3U6sFns2+3QmSkUHe4cfht/ fXTdNzTe52P5en4rO2X9d1lQIcryqb51M/MFd2uatX7VquXDvzmpAZsHCN1TdpYRXDF1 wt3g== X-Gm-Message-State: AAQBX9egpgCcoz9CQDTZzNfQGmcVu6LcYdP8QfGs6rwSMtWjBfUESM2j 1oVTlqVE2aeVYX4hN5qntjEayBAlpW7DxBBAhejSb2EtjBrZlm+dP9O9LrQYoh18fGraM+Xd6hD nwBj09+nwE5s1lmStgJu3dsPdI2uf X-Received: by 2002:a7b:cd8f:0:b0:3ef:67fc:fef1 with SMTP id y15-20020a7bcd8f000000b003ef67fcfef1mr7367801wmj.26.1681121213672; Mon, 10 Apr 2023 03:06:53 -0700 (PDT) X-Google-Smtp-Source: AKy350Z3hwEKUTi1MmJ6HRJ+Rkj89Kq0S+EultviAtUCSE5ycoOtzNa2wHaGq3Rap/lXfHzhxzkS+Q== X-Received: by 2002:a7b:cd8f:0:b0:3ef:67fc:fef1 with SMTP id y15-20020a7bcd8f000000b003ef67fcfef1mr7367786wmj.26.1681121213384; Mon, 10 Apr 2023 03:06:53 -0700 (PDT) Date: Mon, 10 Apr 2023 06:06:49 -0400 From: "Michael S. Tsirkin" To: Jason Wang Cc: Parav Pandit , virtio-dev@lists.oasis-open.org, cohuck@redhat.com, virtio-comment@lists.oasis-open.org, shahafs@nvidia.com, Satananda Burla Message-ID: <20230410060417-mutt-send-email-mst@kernel.org> References: <20230330225834.506969-1-parav@nvidia.com> <20230330225834.506969-10-parav@nvidia.com> <20230407043841-mutt-send-email-mst@kernel.org> <20230410020906-mutt-send-email-mst@kernel.org> <20230410023715-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit Subject: [virtio-dev] Re: [virtio-comment] Re: [PATCH 09/11] transport-pci: Describe PCI MMR dev config registers On Mon, Apr 10, 2023 at 03:20:52PM +0800, Jason Wang wrote: > On Mon, Apr 10, 2023 at 2:40 PM Michael S. Tsirkin wrote: > > > > On Mon, Apr 10, 2023 at 02:20:16PM +0800, Jason Wang wrote: > > > On Mon, Apr 10, 2023 at 2:15 PM Michael S. Tsirkin wrote: > > > > > > > > On Mon, Apr 10, 2023 at 09:33:32AM +0800, Jason Wang wrote: > > > > > This is fine for vDPA but not for virtio if the design can only work > > > > > for some specific setups (OSes/archs). > > > > > > > > > > Thanks > > > > > > > > Well virtio legacy has a long history of documenting existing hacks :) > > > > > > Exactly, so the legacy behaviour is not (or can't be) defined by the > > > spec but the codes. > > > > I mean driver behaviour derives from the code but we do document it in > > the spec to help people build devices. > > > > > > > > But yes, VIRTIO_F_ORDER_PLATFORM has to be documented. > > > > And we have to decide what to do about ACCESS_PLATFORM since > > > > there's a security problem if device allows not acking it. > > > > Two options: > > > > - relax the rules a bit and say device will assume ACCESS_PLATFORM > > > > is acked anyway > > > > > > This will break legacy drivers which assume physical addresses. > > > > not that they are not already broken. > > I may miss something, the whole point is to allow legacy drivers to > run otherwise a modern device is sufficient? yes and if legacy drivers don't work in a given setup then we should not worry. > > > > > > - a new flag that is insecure (so useful for sec but useless for dpdk) but optional > > > > > > This looks like a new "hack" for the legacy hacks. > > > > it's not just for legacy. > > We have the ACCESS_PLATFORM feature bit, what is the useage for this new flag? ACCESS_PLATFORM is also a security boundary. so devices must fail negotiation if it's not there. this new one won't be. > > > > > And what about ORDER_PLATFORM, I don't think we can modify legacy drivers... > > > > > > Thanks > > > > You play some tricks with shadow VQ I guess. > > Do we really want to add a new feature in the virtio spec that can > only work with the datapath mediation? > > Thanks As long as a feature is useful and can't be supported otherwise we are out of options. Keeping field practice things out of the spec helps no one. > > > > -- > > MST > > --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org 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 ws5-mx01.kavi.com (ws5-mx01.kavi.com [34.193.7.191]) (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 04688C77B61 for ; Mon, 10 Apr 2023 10:07:00 +0000 (UTC) Received: from lists.oasis-open.org (oasis.ws5.connectedcommunity.org [10.110.1.242]) by ws5-mx01.kavi.com (Postfix) with ESMTP id BFCD926A59 for ; Mon, 10 Apr 2023 10:06:57 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id A550B986366 for ; Mon, 10 Apr 2023 10:06:57 +0000 (UTC) Received: from host09.ws5.connectedcommunity.org (host09.ws5.connectedcommunity.org [10.110.1.97]) by lists.oasis-open.org (Postfix) with QMQP id 9AC77986319; Mon, 10 Apr 2023 10:06:57 +0000 (UTC) Mailing-List: contact virtio-comment-help@lists.oasis-open.org; run by ezmlm List-ID: Sender: Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id 8396D98631E for ; Mon, 10 Apr 2023 10:06:57 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-MC-Unique: 1NEuKSaPNFSBsOyVl2VPqA-1 X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1681121213; 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=SIuPh0Q7aaEGGPtMDp8rtCrHeHZutODr6kSvT7g9XWY=; b=I+c253FzvwVdGkwr8LjZmTTs3JGP9iWaTDD/LDb0HXtyII1i7z89g4Bg5ki93WlcAM fLlkLrvPicdKuB9YgNwNa9MfwsjOIHvZmZ2EmVap7IiA0f99yNIudbAZAI3fi14hzlce mD6eU/SXYPMBgOAsnWonI++I+7c8N/71nibi4qdYzBVeAza6cbsZSbCJnKEl097kIRpz PWIe4YlJ1f3ovRVEZEnT9FTZLujiR4rDRXjMD8nKB/naHES6bkHG5Hr/AIkmaIOCi1vc 8G/u6kKjRnIYi80cyFTUHNugek+n8TSQu5siF6xfGOn+RKjpQWsh/XUX8y1Wyn9r1lDR pYqg== X-Gm-Message-State: AAQBX9c/YBv2dAkweVahxoGvi6efUTo7/djZzK0pvsoyRYoywsmh5iTH lvgk/2hcYDS0L2VCxfTjN4XUrb1+jAg2l1mv0qljCkYrN9cYp8M1wqW2Clp30s1ylFS66Xoh7fX 7UiB+zdA9oVD54S2hhzq27VhNJdESc7hZpw== X-Received: by 2002:a7b:cd8f:0:b0:3ef:67fc:fef1 with SMTP id y15-20020a7bcd8f000000b003ef67fcfef1mr7367802wmj.26.1681121213673; Mon, 10 Apr 2023 03:06:53 -0700 (PDT) X-Google-Smtp-Source: AKy350Z3hwEKUTi1MmJ6HRJ+Rkj89Kq0S+EultviAtUCSE5ycoOtzNa2wHaGq3Rap/lXfHzhxzkS+Q== X-Received: by 2002:a7b:cd8f:0:b0:3ef:67fc:fef1 with SMTP id y15-20020a7bcd8f000000b003ef67fcfef1mr7367786wmj.26.1681121213384; Mon, 10 Apr 2023 03:06:53 -0700 (PDT) Date: Mon, 10 Apr 2023 06:06:49 -0400 From: "Michael S. Tsirkin" To: Jason Wang Cc: Parav Pandit , virtio-dev@lists.oasis-open.org, cohuck@redhat.com, virtio-comment@lists.oasis-open.org, shahafs@nvidia.com, Satananda Burla Message-ID: <20230410060417-mutt-send-email-mst@kernel.org> References: <20230330225834.506969-1-parav@nvidia.com> <20230330225834.506969-10-parav@nvidia.com> <20230407043841-mutt-send-email-mst@kernel.org> <20230410020906-mutt-send-email-mst@kernel.org> <20230410023715-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit Subject: Re: [virtio-comment] Re: [PATCH 09/11] transport-pci: Describe PCI MMR dev config registers On Mon, Apr 10, 2023 at 03:20:52PM +0800, Jason Wang wrote: > On Mon, Apr 10, 2023 at 2:40 PM Michael S. Tsirkin wrote: > > > > On Mon, Apr 10, 2023 at 02:20:16PM +0800, Jason Wang wrote: > > > On Mon, Apr 10, 2023 at 2:15 PM Michael S. Tsirkin wrote: > > > > > > > > On Mon, Apr 10, 2023 at 09:33:32AM +0800, Jason Wang wrote: > > > > > This is fine for vDPA but not for virtio if the design can only work > > > > > for some specific setups (OSes/archs). > > > > > > > > > > Thanks > > > > > > > > Well virtio legacy has a long history of documenting existing hacks :) > > > > > > Exactly, so the legacy behaviour is not (or can't be) defined by the > > > spec but the codes. > > > > I mean driver behaviour derives from the code but we do document it in > > the spec to help people build devices. > > > > > > > > But yes, VIRTIO_F_ORDER_PLATFORM has to be documented. > > > > And we have to decide what to do about ACCESS_PLATFORM since > > > > there's a security problem if device allows not acking it. > > > > Two options: > > > > - relax the rules a bit and say device will assume ACCESS_PLATFORM > > > > is acked anyway > > > > > > This will break legacy drivers which assume physical addresses. > > > > not that they are not already broken. > > I may miss something, the whole point is to allow legacy drivers to > run otherwise a modern device is sufficient? yes and if legacy drivers don't work in a given setup then we should not worry. > > > > > > - a new flag that is insecure (so useful for sec but useless for dpdk) but optional > > > > > > This looks like a new "hack" for the legacy hacks. > > > > it's not just for legacy. > > We have the ACCESS_PLATFORM feature bit, what is the useage for this new flag? ACCESS_PLATFORM is also a security boundary. so devices must fail negotiation if it's not there. this new one won't be. > > > > > And what about ORDER_PLATFORM, I don't think we can modify legacy drivers... > > > > > > Thanks > > > > You play some tricks with shadow VQ I guess. > > Do we really want to add a new feature in the virtio spec that can > only work with the datapath mediation? > > Thanks As long as a feature is useful and can't be supported otherwise we are out of options. Keeping field practice things out of the spec helps no one. > > > > -- > > MST > > This publicly archived list offers a means to provide input to the OASIS Virtual I/O Device (VIRTIO) TC. In order to verify user consent to the Feedback License terms and to minimize spam in the list archive, subscription is required before posting. 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