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 93A28C76188 for ; Mon, 3 Apr 2023 19:10:25 +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 C3C6426A33 for ; Mon, 3 Apr 2023 19:10:24 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id A5A499863FE for ; Mon, 3 Apr 2023 19:10:24 +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 91479986315; Mon, 3 Apr 2023 19:10:24 +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 7EA679863E4 for ; Mon, 3 Apr 2023 19:10:24 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-MC-Unique: 1YgJlwreMSm2Soro26La8Q-1 Date: Mon, 3 Apr 2023 15:10:14 -0400 From: Stefan Hajnoczi To: Parav Pandit Cc: mst@redhat.com, virtio-dev@lists.oasis-open.org, cohuck@redhat.com, virtio-comment@lists.oasis-open.org, shahafs@nvidia.com Message-ID: <20230403191014.GA350467@fedora> References: <20230330225834.506969-1-parav@nvidia.com> <20230403144523.GC302168@fedora> <46a0db06-f922-2a8a-acf0-cf7e453a2945@nvidia.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="Dgc+T2934FOPeMV9" Content-Disposition: inline In-Reply-To: <46a0db06-f922-2a8a-acf0-cf7e453a2945@nvidia.com> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 Subject: [virtio-dev] Re: [virtio-comment] [PATCH 00/11] Introduce transitional mmr pci device --Dgc+T2934FOPeMV9 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Apr 03, 2023 at 10:53:29AM -0400, Parav Pandit wrote: >=20 >=20 > On 4/3/2023 10:45 AM, Stefan Hajnoczi wrote: > > On Fri, Mar 31, 2023 at 01:58:23AM +0300, Parav Pandit wrote: > > > Overview: > > > --------- > > > The Transitional MMR device is a variant of the transitional PCI devi= ce. > >=20 > > What does "MMR" mean? > >=20 > memory mapped registers. > Explained below in the design section and also in relevant patches 6 to 1= 1. Maybe call it "Memory-mapped Transitional"? That name would be easier to understand. > > Modern devices were added to Linux in 2014 and support SR-IOV. >=20 > > Why is it > > important to support Transitional (which really means Legacy devices, > > otherwise Modern devices would be sufficient)? > >=20 > To support guest VMs which only understand legacy devices and unfortunate= ly > they are still in much wider use by the users. I wonder which guest software without Modern VIRTIO support will still be supported by the time Transitional MMR software and hardware becomes available. Are you aiming for particular guest software versions? Stefan --Dgc+T2934FOPeMV9 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAmQrJJUACgkQnKSrs4Gr c8iFSQgAhWO8PazKwzksUtMyaZfBrHM9d2ixyys8f82VUOXxZrzLF47MdydX9o9H 1xiw/OEHgOg8sRdX7lXQzVtqt0RJ8I/M57xDRFYXDLQpHUi/u68RVS2Ite+pTFIB xoCcrCVw34hL+Yk35voBvKEGA2D2BzJjBuz0G0U5tqF6wTDcKaljMdjoXhGAcyt5 Vu0VqvXqCxb2OgrXAEbChNSGSpPsB8qVifTRN7Xu+JIlZ5giD8ac3DlAtOtaDNzD MbAkUfc5Iudq73umkTohjOAHEnstV+W4rEdGSu8gsIWXKHHLTvNb1+czSNn7jo6o SevC7xL9FBaGcc5GSZdEVsrt0DM/4Q== =RK+t -----END PGP SIGNATURE----- --Dgc+T2934FOPeMV9-- 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 82445C76196 for ; Mon, 3 Apr 2023 19:10:31 +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 CD78F2B02C for ; Mon, 3 Apr 2023 19:10:30 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id BEC6D9864EE for ; Mon, 3 Apr 2023 19:10:30 +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 B663D9863E4; Mon, 3 Apr 2023 19:10:30 +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 A6B2A9863ED for ; Mon, 3 Apr 2023 19:10:30 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-MC-Unique: 1YgJlwreMSm2Soro26La8Q-1 Date: Mon, 3 Apr 2023 15:10:14 -0400 From: Stefan Hajnoczi To: Parav Pandit Cc: mst@redhat.com, virtio-dev@lists.oasis-open.org, cohuck@redhat.com, virtio-comment@lists.oasis-open.org, shahafs@nvidia.com Message-ID: <20230403191014.GA350467@fedora> References: <20230330225834.506969-1-parav@nvidia.com> <20230403144523.GC302168@fedora> <46a0db06-f922-2a8a-acf0-cf7e453a2945@nvidia.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="Dgc+T2934FOPeMV9" Content-Disposition: inline In-Reply-To: <46a0db06-f922-2a8a-acf0-cf7e453a2945@nvidia.com> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 Subject: Re: [virtio-comment] [PATCH 00/11] Introduce transitional mmr pci device --Dgc+T2934FOPeMV9 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Apr 03, 2023 at 10:53:29AM -0400, Parav Pandit wrote: >=20 >=20 > On 4/3/2023 10:45 AM, Stefan Hajnoczi wrote: > > On Fri, Mar 31, 2023 at 01:58:23AM +0300, Parav Pandit wrote: > > > Overview: > > > --------- > > > The Transitional MMR device is a variant of the transitional PCI devi= ce. > >=20 > > What does "MMR" mean? > >=20 > memory mapped registers. > Explained below in the design section and also in relevant patches 6 to 1= 1. Maybe call it "Memory-mapped Transitional"? That name would be easier to understand. > > Modern devices were added to Linux in 2014 and support SR-IOV. >=20 > > Why is it > > important to support Transitional (which really means Legacy devices, > > otherwise Modern devices would be sufficient)? > >=20 > To support guest VMs which only understand legacy devices and unfortunate= ly > they are still in much wider use by the users. I wonder which guest software without Modern VIRTIO support will still be supported by the time Transitional MMR software and hardware becomes available. Are you aiming for particular guest software versions? Stefan --Dgc+T2934FOPeMV9 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAmQrJJUACgkQnKSrs4Gr c8iFSQgAhWO8PazKwzksUtMyaZfBrHM9d2ixyys8f82VUOXxZrzLF47MdydX9o9H 1xiw/OEHgOg8sRdX7lXQzVtqt0RJ8I/M57xDRFYXDLQpHUi/u68RVS2Ite+pTFIB xoCcrCVw34hL+Yk35voBvKEGA2D2BzJjBuz0G0U5tqF6wTDcKaljMdjoXhGAcyt5 Vu0VqvXqCxb2OgrXAEbChNSGSpPsB8qVifTRN7Xu+JIlZ5giD8ac3DlAtOtaDNzD MbAkUfc5Iudq73umkTohjOAHEnstV+W4rEdGSu8gsIWXKHHLTvNb1+czSNn7jo6o SevC7xL9FBaGcc5GSZdEVsrt0DM/4Q== =RK+t -----END PGP SIGNATURE----- --Dgc+T2934FOPeMV9--