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 2052FC76196 for ; Mon, 10 Apr 2023 10:05:28 +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 C10AD2AC5A for ; Mon, 10 Apr 2023 10:05:27 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id 53EAC98660D for ; Mon, 10 Apr 2023 10:05:27 +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 BF6A798636D; Mon, 10 Apr 2023 10:05:26 +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 692B8986321 for ; Mon, 10 Apr 2023 10:04:11 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-MC-Unique: 9kD0_81wOvKdOVfWTa1MSg-1 X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1681121048; 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=jtEbMCwMnkI2VdNhYUQPmDl2IgpBxhJ69FS4TtXZ9j8=; b=6RCnacZK7sGUCVMR9fZ+biQrWzg/IvrrzUughLhqSzZqjknKvGPB4rzQpt/Q0PBqE+ g9TD+iqSrenGxDlpUGg7gV/KM6j+OmKvI7Ur+S1FHY6DjqGfbfWSQc8qoB8f9mcTM5G4 +wKNcXpH47oHs9fBZ77X3BSuMlV2jMQm6g6re0ec+fSGf9cKVbW+ITqsTrC6rEHJRehK dgDrjlX+CjLS8cnc/ma5qYw1QCyrDXo1y9QhuUx0Vc/tqyVG8qQ5g9bpAKGswHP53Yp+ mazf0el3yDAEKByg/8lfcILnIy0CDKA5480lhqK6hlc42uUmpWxVlGp48GB1k/nA+Seu iXtA== X-Gm-Message-State: AAQBX9cZ8twHHr3lXp0axxdzRq/qtkvF5cTs4kK2/LhXX2G7eI0PjQgK x55NcRTKHry+bKvBbnVM4S+9OAoTjfHNitHQl+RlCgCySwPaMg6Mb5hBiVXm6nc/hO0Bo8MVrdg 4OfjaHNXzwPdpvQQ1mRS80WhBf/2v X-Received: by 2002:a1c:f219:0:b0:3ea:d620:57a7 with SMTP id s25-20020a1cf219000000b003ead62057a7mr7219781wmc.8.1681121048101; Mon, 10 Apr 2023 03:04:08 -0700 (PDT) X-Google-Smtp-Source: AKy350ZPXmVZcVyMjFIOdnBtpKQoncHXttB5viMKOgSDbZnlDMH3eTAQE0TsdoH+r0NwhQ+iWgTALw== X-Received: by 2002:a1c:f219:0:b0:3ea:d620:57a7 with SMTP id s25-20020a1cf219000000b003ead62057a7mr7219769wmc.8.1681121047811; Mon, 10 Apr 2023 03:04:07 -0700 (PDT) Date: Mon, 10 Apr 2023 06:04:04 -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: <20230410055947-mutt-send-email-mst@kernel.org> References: <20230330225834.506969-1-parav@nvidia.com> <20230330225834.506969-9-parav@nvidia.com> <20230410021619-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-dev] [PATCH 08/11] transport-pci: Introduce virtio extended capability On Mon, Apr 10, 2023 at 03:16:46PM +0800, Jason Wang wrote: > On Mon, Apr 10, 2023 at 2:24 PM Michael S. Tsirkin wrote: > > > > On Mon, Apr 10, 2023 at 09:36:17AM +0800, Jason Wang wrote: > > > On Fri, Mar 31, 2023 at 7:00 AM Parav Pandit wrote: > > > > > > > > PCI device configuration space for capabilities is limited to only 192 > > > > bytes shared by many PCI capabilities of generic PCI device and virtio > > > > specific. > > > > > > > > Hence, introduce virtio extended capability that uses PCI Express > > > > extended capability. > > > > Subsequent patch uses this virtio extended capability. > > > > > > > > Co-developed-by: Satananda Burla > > > > Signed-off-by: Parav Pandit > > > > > > Can you explain the differences compared to what I've used to propose? > > > > > > https://www.mail-archive.com/virtio-dev@lists.oasis-open.org/msg08078.html > > > > > > This can save time for everybody. > > > > > > Thanks > > > > BTW another advantage of extended capabilities is - these are actually > > cheaper to access from a VM than classic config space. > > Config space/BAR is allowed by both of the proposals or anything I missed? > > > > > > > Several points > > - I don't like it that yours is 32 bit. We do not need 2 variants just > > make it all 64 bit > > That's fine. > > > - We need to document that if driver does not scan extended capbilities it will not find them. > > This is implicit since I remember we don't have such documentation for > pci capability, anything makes pcie special? yes - the fact that there are tons of existing drivers expecting everything in standard space. > > And existing drivers do not scan them. So what is safe > > to put there? vendor specific? extra access types? > > For PASID at least, since it's a PCI-E feature, vendor specific should > be fine. Not sure about legacy MMIO then. > > > Can we make scanning these mandatory in future drivers? future devices? > > I guess we can add a feature bit to flag that. > > For PASID, it doesn't need this, otherwise we may duplicate transport > specific features. i don't get it. what does PASID have to do with it? A new feature will allow clean split at least: we make any new features and new devices that expect express capability depend on this new feature bit. > > Is accessing these possible from bios? > > Not at least for the two use cases now PASID or legacy MMIO. can't parse english here. what does this mean? > > > > So I like this one better as a basis - care reviewing it and adding > > stuff? > > There are very few differences and I will have a look. > > Thanks > > > > > -- > > 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 E7B10C77B61 for ; Mon, 10 Apr 2023 10:05:27 +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 0C1462B019 for ; Mon, 10 Apr 2023 10:05:27 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id D57EC9863D1 for ; Mon, 10 Apr 2023 10:05:26 +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 BE965986319; Mon, 10 Apr 2023 10:05:26 +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 66D5498631E for ; Mon, 10 Apr 2023 10:04:11 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-MC-Unique: jhllW8BRMHGfcdajyw_c0Q-1 X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1681121048; 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=jtEbMCwMnkI2VdNhYUQPmDl2IgpBxhJ69FS4TtXZ9j8=; b=g/h3cKyTFE/+fAwlhfdV9mHmN6H3EZmRR2IeXWSSW1zHMpzHT2ExWwSJCYvBAWnGrC XVMzUuVh6rax2LtAGHdiNgYB7FQKGeHJLsdKBhz0Zxs2X70tkLgVvAyZa9Ksk7Ve+7hG rIFedsG8iy0r4+uAvhVVBSGIwEemSdEgXL2aLDN9g4wyFy9+daFvm1Wys7cwtUoIh6Zg 39bC9TbUc6F/KRgOBAYdl5LaRCauDhWE8S9uLijwqFDIJoawIEhFdXY8/eSpieREL/Pw TqTCMNlXSmUnISwA8/ZokUGp4dHyclTrB7t3Eq1pp3znD2pwlEnmYbVSV0q+j943Fggb ERJA== X-Gm-Message-State: AAQBX9fBFp5FB9kDcQnlIPonPo/qsPmG+t/gR6uuPGfBFBDKb3qI0tSV vcFmxDXEIP1d/fFWO12ibxmpile9SWVyzvLDV0ZC8cDNYzKFf8YCURPxQHRLC10OfhielfsLNlT T/1DJFUKv8tc0nfg73pipgRhjpj/01F9Plw== X-Received: by 2002:a1c:f219:0:b0:3ea:d620:57a7 with SMTP id s25-20020a1cf219000000b003ead62057a7mr7219783wmc.8.1681121048101; Mon, 10 Apr 2023 03:04:08 -0700 (PDT) X-Google-Smtp-Source: AKy350ZPXmVZcVyMjFIOdnBtpKQoncHXttB5viMKOgSDbZnlDMH3eTAQE0TsdoH+r0NwhQ+iWgTALw== X-Received: by 2002:a1c:f219:0:b0:3ea:d620:57a7 with SMTP id s25-20020a1cf219000000b003ead62057a7mr7219769wmc.8.1681121047811; Mon, 10 Apr 2023 03:04:07 -0700 (PDT) Date: Mon, 10 Apr 2023 06:04:04 -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: <20230410055947-mutt-send-email-mst@kernel.org> References: <20230330225834.506969-1-parav@nvidia.com> <20230330225834.506969-9-parav@nvidia.com> <20230410021619-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-comment] Re: [virtio-dev] [PATCH 08/11] transport-pci: Introduce virtio extended capability On Mon, Apr 10, 2023 at 03:16:46PM +0800, Jason Wang wrote: > On Mon, Apr 10, 2023 at 2:24 PM Michael S. Tsirkin wrote: > > > > On Mon, Apr 10, 2023 at 09:36:17AM +0800, Jason Wang wrote: > > > On Fri, Mar 31, 2023 at 7:00 AM Parav Pandit wrote: > > > > > > > > PCI device configuration space for capabilities is limited to only 192 > > > > bytes shared by many PCI capabilities of generic PCI device and virtio > > > > specific. > > > > > > > > Hence, introduce virtio extended capability that uses PCI Express > > > > extended capability. > > > > Subsequent patch uses this virtio extended capability. > > > > > > > > Co-developed-by: Satananda Burla > > > > Signed-off-by: Parav Pandit > > > > > > Can you explain the differences compared to what I've used to propose? > > > > > > https://www.mail-archive.com/virtio-dev@lists.oasis-open.org/msg08078.html > > > > > > This can save time for everybody. > > > > > > Thanks > > > > BTW another advantage of extended capabilities is - these are actually > > cheaper to access from a VM than classic config space. > > Config space/BAR is allowed by both of the proposals or anything I missed? > > > > > > > Several points > > - I don't like it that yours is 32 bit. We do not need 2 variants just > > make it all 64 bit > > That's fine. > > > - We need to document that if driver does not scan extended capbilities it will not find them. > > This is implicit since I remember we don't have such documentation for > pci capability, anything makes pcie special? yes - the fact that there are tons of existing drivers expecting everything in standard space. > > And existing drivers do not scan them. So what is safe > > to put there? vendor specific? extra access types? > > For PASID at least, since it's a PCI-E feature, vendor specific should > be fine. Not sure about legacy MMIO then. > > > Can we make scanning these mandatory in future drivers? future devices? > > I guess we can add a feature bit to flag that. > > For PASID, it doesn't need this, otherwise we may duplicate transport > specific features. i don't get it. what does PASID have to do with it? A new feature will allow clean split at least: we make any new features and new devices that expect express capability depend on this new feature bit. > > Is accessing these possible from bios? > > Not at least for the two use cases now PASID or legacy MMIO. can't parse english here. what does this mean? > > > > So I like this one better as a basis - care reviewing it and adding > > stuff? > > There are very few differences and I will have a look. > > Thanks > > > > > -- > > 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. Subscribe: virtio-comment-subscribe@lists.oasis-open.org Unsubscribe: virtio-comment-unsubscribe@lists.oasis-open.org List help: virtio-comment-help@lists.oasis-open.org List archive: https://lists.oasis-open.org/archives/virtio-comment/ Feedback License: https://www.oasis-open.org/who/ipr/feedback_license.pdf List Guidelines: https://www.oasis-open.org/policies-guidelines/mailing-lists Committee: https://www.oasis-open.org/committees/virtio/ Join OASIS: https://www.oasis-open.org/join/