From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Sender: 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 565399863C0 for ; Mon, 30 Jan 2023 20:30:37 +0000 (UTC) Date: Mon, 30 Jan 2023 15:30:25 -0500 From: Stefan Hajnoczi Message-ID: References: <961D315C9D3A523B+202301111121345064138@sudoinfotech.com> <20230119064213-mutt-send-email-mst@kernel.org> <7E9D0395E3E96E2E+2023012911324146420712@sudoinfotech.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="sWg+sHkRJ041AMU2" Content-Disposition: inline In-Reply-To: <7E9D0395E3E96E2E+2023012911324146420712@sudoinfotech.com> Subject: Re: Re: [virtio-comment] About adding a new device type virtio-nvme To: =?utf-8?B?5L6v6Iux5LmQ?= Cc: "Michael S. Tsirkin" , virtio-comment , Christoph Hellwig , Keith Busch , Kevin Wolf , Klaus Jensen , sgarzare List-ID: --sWg+sHkRJ041AMU2 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sun, Jan 29, 2023 at 11:32:43AM +0800, =E4=BE=AF=E8=8B=B1=E4=B9=90 wrote: > Thu, 19 Jan 2023 06:42:49 -0500, Michael S. Tsirkin wrote: >=20 > >On Tue, Jan 17, 2023 at 11:01:37AM -0500, Stefan Hajnoczi wrote: >=20 > >> > The NVME technology and ecosystem are complete. However, in virtuali= zation scenarios, NVME devices can only use PCIe pass-through . When NVME a= nd virtio combine to connect to the vDPA ecosystem, live migration is suppo= rted. >=20 > >> > >=20 > >> > >=20 > >> > >Let's not forget that virtio-blk is widely used and new commands are >=20 > >> > >being added as needed. Which NVMe features are you missing in >=20 > >> > >virtio-blk? >=20 > >> > >=20 > >> > With the introduction of the concept of DPU, a large number of vendo= rs are offloading virtual devices to hardware. The back-end of Virtio-blk d= oes not support remote storage. Therefore, Virtio-Nvme-of can well combine = the advantages of remote storage and virtio live migration >=20 > >> >=20 > >> virtio-blk is just a storage interface, whether that storage is local = or >=20 > >> remote is up to the device implementation. The block device could be >=20 > >> located on Ceph, NFS, etc. >=20 > >> >=20 > >> Each virtio-blk device is a single block device. There is no >=20 > >> standardized management protocol in virtio-blk for connecting to remote >=20 > >> block devices. I'm aware of hardware virtio-blk devices that connect to >=20 > >> remote storage. Configuration is performed through an out-of-band >=20 > >> management interface. >=20 > >> >=20 > >> Maybe when you say virtio-blk doesn't support remote storage this is >=20 > >> what you mean? >=20 > >> >=20 > >> Stefan >=20 > > > >=E4=BE=AF=E8=8B=B1=E4=B9=90 you never answered this question. >=20 >=20 > All the topics revolve around the scenario where the virtio device is off= loading into the DPU. > Virtio has a front-end and a back-end. What I mean is that I want to impl= ement the back-end of Virtio-blk on the DPU. You can do that today and the underlying storage can be remote. Can you explain what you mean when you say virtio-blk doesn't support remote storage? Stefan --sWg+sHkRJ041AMU2 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAmPYKOEACgkQnKSrs4Gr c8hYAgf/R3DR5pYqxZAmvf8OdhTVx/L8jzGb6wUBjbVNf7Xur0u2zvH+6OrboVO+ GXyQYPNwbRBE11tehsR/zSFu1v1nFbvHAjUMaM70fBkuZC/v1yQ76rdHxLlQRyFr S+p3Xe3JQwzF4UMo9nmpjEGu8WOZAKo16VrB0h5hAnhR8UZhITHm+IXDRgsXRUCP 6PvKRPAH6FE9NvRrShCP4bgZEIkr5I90wKnzPUuz7hCuYXazlLd9lDktQuzjZtmj /nmyz69ij95mE2dh3//y3clvsYBqypNCV0PXDGcXWjmuZJfIFxk1gXDyv6ZG5f7N beqWuX0lhRZDMZZ8uyvAAK6TwUiDcw== =0gQN -----END PGP SIGNATURE----- --sWg+sHkRJ041AMU2--